description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
The present invention relates to double-glazing insulating panels.
HISTORY OF THE RELATED ART
For dressing facades, particularly in office buildings, modern architecture calls upon transparent panels appropriately fixed on a virtually invisible frame, such panels comprising two panes of glass, double-glazing, mounted in a tight manner on a peripheral chassis.
It is an object of the present invention to provide such panels with a motorized screen device directly incorporated inside the tight intermediate space formed between the double-glazing.
SUMMARY OF THE INVENTION
To that end, the invention consists essentially in providing the upper part of the the intermediate space with a cradle element forming an envelope for a rotating drum to which is secured the upper horizontal edge of a supple screen engaged through a longitudinal slot in the cradle element. The rotation of this drum in the two directions is accomplished by a drive mechanism introduced in the drum by axial slide from one of the ends thereof. The corresponding end of the drive mechanism is fixed in dismountable manner to a removable stopper tightly engaged in an opening made laterally in the chassis or frame of the panel.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which:
FIG. 1 is a schematic vertical section of the upper part of a panel according to the present invention.
FIG. 2 is a horizontal section of a detail, on a larger scale, along the plane indicated at II--II in FIG. 1.
FIG. 3 illustrates in perspective the arrangement of the cradle element and its fixation inside the panel.
FIG. 4 shows in perspective and exploded, the elements which serve to obturate the opening made laterally in the frame for assembling the drive mechanism of the screen device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, the insulating panel shown in FIGS. 1 and 2 comprises in manner known per se, two transparent sheets or panes 1 and 2 of which the edges are secured within a square or rectangular frame 3, with the interposition of O-rings 4. It will be observed that the thickness of this panel is slightly greater than that of the conventional panels of the same type, so that the intermediate space formed between the panes 1 and 2 is capable of receiving the motorized screen mechanism which will be described hereinbelow. Of course, the atmosphere of this intermediate space, treated to avoid any condensation, is sealed from the outside atmosphere.
When the panel is constructed, it is provided with a cradle element 5 which, as shown in FIG. 3, is of substantially circular cross-section. The cradle element 5 includes a longitudinal slot 5a which extends over its entire length and which faces obliquely downwardly. Opposite this slot 5, the cradle element 5 is provided with two vertical extensions 5b of which the upper edge includes a flange 5c sectioned to from a longitudinal groove. This groove is adapted to cooperate, by axially sliding the cradle element 5, with two corresponding longitudinal guide flanges 3a provided at the inner face of a section of the frame consequently supporting of the cradle element in the frame.
In the cradle element 5 is mounted a winding drum 6, on the periphery of which is fixed the upper edge of a blind or like screen shown schematically at 7 in FIG. 1, which screen is engaged through the lower slot 5a so as to allow vertical displacement thereof inside the intermediate space, by rotation of the drum 6. The drum is centred in rotation in the cradle element 5; to that end, one of its ends is closed by an endpiece 8 mounted on a pin 8a on the projecting end of which is idly mounted a side element 9 of circular section, secured at its periphery to the inner wall of the cradle element 5.
Drum 6 is driven in rotation by a mechanism housed inside the drum and which comprises, in conventional manner, an electric motor 10 associated with a speed reducer 11. The driven shaft 11a of the reducer 11 is sectioned so as to be fitted, by axial displacement of assembly 10-11, inside the hub of a drive member 12 which is secured to drum 6.
Opposite reducer 11, the motor 10 is supported in removable manner inside the drum 6 by an endpiece 13a of square section, adapted to fit axially in the central part of the casing of the motor. This endpiece 13a is secured to a support 13 arranged in the manner of a removable stopper adapted to be engaged by force inside an annular seal 14 which is mounted inside an opening 3b provided laterally in the frame 3.
FIGS. 2 and 4 clearly show the arrangement of the stopper 13 and seal 14. The axial opening of this seal 14 presents a truncated section to which corresponds on the stopper 13 a conjugate part, followed by a cylindrical axial extension adapted to engage in the opening of a guide ring 15 fitted by force inside the corresponding opening of the cradle element 5, which ring thus ensures the centering of the end of the drum 6.
For the passage of the cable 16 which provides electrical power to the motor 10, there is arranged in the stopper 13 a longitudinal bore 13b which must, of course, be rendered tight after assembly of motor-reducer assembly 10-11 in the drum 6. To that end, a bushing 17 is employed, made of a deformable material in order to serve as stuffing box. This bushing 17 is carried by a pusher 18 of half-moon section, introduced in a recess 13c in the stopper 13 and retained in place by screws.
To avoid any untimely axial displacement of stopper 13 once positioned with the pusher 18, the invention provides a key 19 having an elongated opening 19a cut therein, intended to overlap the cable 16. This key 19 is introduced, by vertically sliding from an inlet 3d (FIG. 4) made in the frame 3, in a recess defined by outer longitudinal ribs 3e of the frame.
It will be observed that the stopper 13 is advantageously provided, on its outer face, with projections 13d identical to ribs 3e of the outer face of the frame 3. Consequently, a continuous profile is obtained which allows the conventional seal associated with each panel to be positioned.
The advantages offered by the structure which has just been described will be readily understood. The insulating panel obtained is equipped with a motorized screen device which is incorporated in the panel and which can be manoeuvred by a reversible switch of conventional type, it being, however, noted that, in the case in question, adjustment of the ends-of-stroke of the screen must be able to be effected by means of the reversible switch mentioned. In the event of failure, the drive mechanism 10-11 may be replaced by extracting the key 19 and the stopper 13 with its pusher 18 and the stuffing box 17; after a new assembly has been positioned, the internal atmosphere is treated before closing of the opening of the frame by the stopper 13 and its related components. | A double-glazing insulation panel having a pair of panes which define an intermediate space in which is mounted a drum for use in vertically adjusting a screen and which the drive mechanism for the drum is removably mounted through an opening in the frame of the panel and supported relative thereto by a stopper assembly which is used to seal the opening through the frame. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation application, claiming priority to the United States application for patent, having the Ser. No. 12/653,152, filed Dec. 9, 2009 now U.S. Pat. No. 8,196,515, the entirety of which is incorporated herein by reference.
FIELD
The present invention relates, generally, to a power source usable to actuate a subsurface tool.
BACKGROUND
Subsurface tools, placed downhole within a well, are used for a variety of purposes. Such tools can include packers or plugs, cutters, other similar downhole tools, and setting tools used in conjunction with such devices.
For example, in a typical downhole operation, a packer can be lowered into a well and positioned at a desired depth, and a setting tool can be positioned above the packer in operative association therewith. An explosive power charge is then provided in conjunction with the setting tool. When it is desired to set the packer, the power charge is initiated, which causes gas to be rapidly produced, forcefully driving a movable portion of the setting tool into a position to actuate the packer to seal a desired area of the well. The gas can also provide sufficient force to shear a shear pin or similar frangible member to separate the setting tool from the packer.
The force applied to a subsurface tool by a power charge and/or a setting tool must be carefully controlled. The force must be sufficient to set a packer or to similarly actuate a downhole tool; however, excessive force can damage portions of the downhole tool, rendering it ineffective. Additionally, the power charge must be configured to provide force for a sufficient period of time. An explosive force provided for an extremely short duration can fail to actuate a tool, and in many cases a “slow set” is preferred due to favorable characteristics provided when actuating a tool in such a manner. For example, when setting a packer, a “slow set” provides the packer with improved holding capacity.
Conventional power charges are classified as explosive devices. Most power charges include black powder and/or ammonium perchlorate, and are configured to provide a short, forceful pressure to a subsurface tool to actuate the tool. An explosive force can often create shockwaves within a well bore, which can undesirably move and/or damage various tools and other components disposed within.
Classification of power charges as explosive devices creates numerous difficulties relating to their transport and use. Shipment of explosive devices on commercial carriers, such as passenger and cargo airplanes, is prohibited. Further, shipment of explosive devices via most trucking companies or similar ground transport is also prohibited. Permissible truck, rail, and ship-based modes of transport are burdened by exacting and costly requirements. Shipments of explosives by rail require buffering areas around an explosive device, resulting in inefficient spacing of cargo with increased cost to the shipper. Shipments by truck require use of vehicles specifically equipped and designated to carry explosive devices, which is a costly process due to the hazards involved. Shipment using ships is subject to regulation by port authorities of various nations, grounded in national security concerns, which greatly increases the time and expense required for the shipment.
The difficulties inherent in the shipment of explosive devices are complicated by the fact that numerous oil and gas wells requiring use of power charges are located in remote locales, which are subject to various national and local regulations regarding explosive devices, and which often require numerous modes of transportation and numerous carriers to reach.
Operation of explosive power charges is also restricted, depending on the location in which an operation is to be performed. In many locations, the user of a power charge must be specifically licensed to handle and operate explosive devices. Some nations do not allow transport or use of explosive devices within their borders without obtaining a special permit to requisition a desired explosive device from a designated storage area. In others, various governmental agents or other specialists must be present to ensure safe operation of the device.
In addition to the regulatory difficulties present when using an explosive power charge, the explosive nature of conventional power charges can also inhibit the effectiveness of such devices.
In some instances, a packer or similar subsurface tool can become misaligned within a wellbore. Use of an explosive power charge to provide a short, powerful burst of pressure to actuate the tool can cause the tool to set, or otherwise become actuated, in a misaligned orientation, hindering its effectiveness. While conventional power charges are configured to provide a sustained pressure over a period of time, this period of time is often insufficient to allow a misaligned tool to become realigned within a wellbore, while a longer, slower application of pressure (a “slow set”) can cause a tool to become aligned as it is actuated. Additionally, a longer, slower application of pressure to a subsurface tool can improve the quality of the actuation of the tool, as described previously.
A further complication encountered when using explosive power charges relates to the heat transfer created by the device. Conventional power charges can heat a subsurface tool to temperatures in excess of 2,000 degrees Fahrenheit. These extreme temperatures can cause excessive wear to tool components, leading to the degradation of one or more portions of the tool.
A need exists for a power source, usable as an alternative to conventional power charges, that does not contain explosive substances, thereby avoiding the difficulties inherent in the transport and use of explosive devices.
A further need exists for a power source that provides a continuous pressure to a subsurface tool over an extended period of time, enabling alignment of misaligned tools and improving the quality of the actuation of the subsurface tool, while providing an aggregate pressure equal to or exceeding that provided by conventional power charges.
A need also exists for a power source that provides pressure sufficient to actuate a subsurface tool without increasing the temperature of the tool to an extent that can cause significant damage or degradation.
The present invention meets these needs.
SUMMARY
The present invention relates, generally, to a power source, usable to actuate a variety of subsurface tools, such as packers, plugs, cutters, and/or a setting tool operably associated therewith. The present power source incorporates use of non-explosive, reactive components that can provide a pressure sufficient to actuate a subsurface tool. The aggregate pressure provided during the reaction of the components can equal or exceed that provided by a conventional explosive power charge. By omitting use of explosive components, the present power source is not subject to the burdensome restrictions relating to use and transport of explosive devices, while providing a more continuous pressure over a greater period of time than a conventional explosive power charge.
In an embodiment of the invention, the present power source includes thermite, present in a quantity sufficient to generate a thermite reaction. Thermite is a mixture that includes a powdered or finely divided metal, such as aluminum, magnesium, chromium, nickel, and/or similar metals, combined with a metal oxide, such as cupric oxide, iron oxide, and/or similar metal oxides. The ignition point of thermite can vary, depending on the specific composition of the thermite mixture. For example, the ignition point of a mixture of aluminum and cupric oxide is about 1200 degrees Fahrenheit. Other thermite mixtures can have an ignition point as low as 900 degrees Fahrenheit.
When ignited, the thermite produces a non-explosive, exothermic reaction. The rate of the thermite reaction occurs on the order of milliseconds, while an explosive reaction has a rate occurring on the order of nanoseconds. While explosive reactions can create detrimental explosive shockwaves within a wellbore, use of a thermite-based power charge avoids such shockwaves.
The power source also includes a gas producing substance and/or compound disposed in association with the thermite. Pressure from the gas produced is usable to actuate a subsurface tool, such as by causing movement of a movable portion of a tool from a first position to a second position. In a preferred embodiment, the substance and/or compound includes a polymer that that produces gas responsive to the thermite reaction, and as such, the present application will refer to use of a “polymer” throughout; however, it should be understood that the term “polymer” is used synonymously with any substance that can produce gas responsive to a thermite reaction.
Usable polymers can include, without limitation, polyethylene, polypropylene, polystyrene, polyester, polyurethane, acetal, nylon, polycarbonate, vinyl, acrylin, acrylonitrile butadiene styrene, polyimide, cylic olefin copolymer, polyphenylene sulfide, polytetrafluroethylene, polyketone, polyetheretherketone, polytherlmide, polyethersulfone, polyamide imide, styrene acrylonitrile, cellulose propionate, diallyl phthalate, melamine formaldehyde, other similar polymers, or combinations thereof.
In a preferred embodiment of the invention, the polymer can take the shape of a container, disposed exterior to and at least partially enclosing the thermite. Other associations between a polymer and thermite are also usable, such as substantially mixing the polymer with the thermite, or otherwise combining the polymer and thermite such that the polymer produces gas responsive to the thermite reaction. For example, a usable polymer can be included within a thermite mixture as a binding agent. In an embodiment of the invention, a polymer can be present in an amount ranging from 110% the quantity of thermite to 250% the quantity of thermite, and in a preferred embodiment, in an amount approximately equal to 125% the quantity of thermite.
Use of a power source that includes thermite and a polymer that produces gas when the thermite reaction occurs provides increased pressure when compared to reacting thermite without a polymer. Use of thermite alone can frequently fail to produce sufficient pressure to actuate a subsurface tool.
The gas produced by the polymer can slow the thermite reaction, while being non-extinguishing of the thermite reaction, which enables the power source to provide a continuous pressure over a period of time. In an embodiment of the invention, the thermite reaction, as affected by the gas, can occur over a period of time in excess of one minute. The aggregate pressure produced by the power source over the time within which the thermite reaction occurs can exceed the pressure provided by a conventional explosive power charge. Additionally, use of a continuous pressure, suitable for a “slow set,” can improve the quality of the actuation of certain subsurface tools, such as packers. Further, when a packer or a similar tool has become misaligned in a borehole, application of a continuous, steadily increasing pressure over a period of time can cause the misaligned tool to straighten as it is actuated. Use of an explosive burst of force provided by a conventional power charge would instead cause a misaligned tool to become actuated in an improper orientation.
In embodiments of the invention where a “slow set” is not desired, such as when actuating a subsurface tool requiring pressure to be exerted for a period of time less than that of the thermite reaction, one or more accelerants can also be included within the power source. For example, inclusion of magnesium or a similar accelerant, in association with the thermite and/or the polymer can cause a reaction that would have occurred over a period of two to three minutes to occur within ten to twenty seconds.
In a further embodiment of the invention, the polymer and/or the gas can reduce the heat transfer from the thermite reaction to the subsurface tool, or another adjacent object. While typically, the exothermic thermite reaction can increase the temperature of an adjacent subsurface tool by up to 6,000 degrees Fahrenheit, potentially causing wear and/or degradation of the tool, an embodiment of the present power source can include a quantity and configuration of thermite and polymer that controls the heat transfer of the reaction such that the temperature of an adjacent subsurface tool is increased by only 1000 degrees Fahrenheit or less. During typical use, the present power source can increase the temperature of an adjacent tool by only 225 degrees Fahrenheit or less.
In operation, a power source, as described above, can be provided in operative association with a movable member of a subsurface tool. For example, a packer secured to a setting tool, having a piston or mandrel used to actuate the packer, can be lowered into a wellbore, the power source being placed adjacent to, or otherwise in operative association with, the piston or mandrel. A thermal generator, torch, or similar device usable to begin the thermite reaction can be provided in association with the thermite.
When the tool has been lowered to a selected depth and it is desirable to actuate the tool, the thermal generator can be used to initiate the thermite reaction, such as by providing current to the thermal generator through electrical contacts with a source of power located at the well surface. The power source can also be actuated using a self-contained thermal generator that includes batteries, a mechanical spring, and/or another source of power usable to cause the thermal generator to initiate the thermite reaction. Initiation of the reaction can be manual, or the reaction can be initiated automatically, responsive to a number of conditions including time, pressure, temperature, motion, and/or other factors or conditions, through use of various timers and/or sensors in communication with the thermal generator.
As the thermite reacts, the polymer produces gas, and the gas from the polymer and/or the thermite reaction applies a pressure to the movable member sufficient to actuate the subsurface tool. The gas from the polymer slows the thermite reaction, thereby enabling, in various embodiments of the invention, provision of a continuous pressure to the movable member over a period of time, and/or prevention of excessive heat transfer from the thermite reaction to the subsurface tool. The thermite reaction can provide a continuous, increasing pressure such that if a packer or similar tool has become misaligned, pressure from the power source will push the tool into alignment prior to actuating the tool.
The force provided by the power source can be controlled by varying the quantity of thermite and/or the quantity of polymer. In an embodiment of the invention, the force provided by the power source can be used to perform actions subsequent to actuating the subsurface tool. For example, after actuating a setting tool to cause setting of a packer, the force from the power source can shear a shear pin or similar item to cause separation of the setting tool from the packer.
Embodiments of the present power source thereby provide a non-explosive alternative to conventional explosive power charges, that can provide a continuous pressure over a period of time that equals or exceeds the aggregate pressure provided by conventional alternatives, and can reduce heat transfer from the power source to a subsurface tool.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description of various embodiments of the present invention presented below, reference is made to the accompanying drawings, in which:
FIG. 1 depicts an embodiment of a subsurface tool within a wellbore, in operative association with an embodiment of the present power source.
FIG. 2 depicts a cross-sectional view of an embodiment of the present power source.
Embodiments of the present invention are described below with reference to the listed Figures.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Before explaining selected embodiments of the present invention in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein and that the present invention can be practiced or carried out in various ways.
Referring now to FIG. 1 , an embodiment of the present power source is shown within a wellbore, in operative association with a subsurface tool.
Specifically, FIG. 1 depicts a wellbore ( 13 ), drilled within the earth ( 14 ), extending from the surface ( 16 ) to a desired depth. The wellbore has a packer ( 11 ) disposed therein. While FIG. 1 depicts a cased wellbore ( 13 ), it should be noted that embodiments of the power source are usable within any type of hole or opening, including cased or uncased wells, open holes, mines, platforms over subsurface openings, or other similar subsurface locations beneath land or water, as well as above-ground locations where production of a gas and/or pressure is desirable to actuate a tool and/or for other purposes. Additionally, while FIG. 1 depicts the wellbore ( 13 ) containing a packer ( 11 ), embodiments of the present power source are usable to actuate any type of subsurface tool, including without limitation, packers, plugs, cutters, setting tools, and other devices able to be actuated using pressure.
The packer ( 11 ) is shown in operative association with a setting tool ( 15 ), usable to actuate the packer ( 11 ). Exemplary setting tools can include such tools as Baker No. 10 and No. 20, from Baker Oil Tools. Another exemplary setting tool is described in U.S. Pat. No. 5,396,951, the entirety of which is incorporated herein by reference. Through actuation by the setting tool ( 15 ), the packer ( 11 ) deploys sealing members ( 51 ) against the inner circumference of the wellbore ( 13 ).
A firing head ( 17 ) is shown coupled to the setting tool ( 15 ), the firing head ( 17 ) containing an embodiment of the present power source (not visible in FIG. 1 ). The power source within the firing head ( 17 ) is operatively coupled with a movable member of the setting tool ( 15 ) (for example a movable piston ( 43 ), as shown in FIG. 2 ), such that gas produced by the power source applies, to the setting tool ( 15 ), a pressure sufficient to cause actuation of the setting tool ( 15 ). An electrical conduit ( 45 ) is shown connecting the firing head ( 17 ) to a source of power (not shown) disposed at the surface ( 16 ), for ignition of the power source. Other sources of power, such as batteries, a downhole source of power, a mechanical source of power, or similar sources of power, are also usable, such that a electrical connection between the firing head ( 17 ) and the surface ( 16 ) is not required.
Referring now to FIG. 2 , an embodiment of the present power source ( 21 ) is shown, disposed within the firing head ( 17 ). The power source ( 21 ) is shown including a quantity of thermite ( 23 ), partially encased by a polymer ( 25 ), the polymer ( 25 ) defining a bottom wall ( 31 ) and a side wall ( 33 ). In one or more embodiments of the invention, the bottom wall ( 31 ) and/or the side wall ( 33 ) can be omitted, and the thermite ( 23 ) can be pressed against a stop or wall within the firing head ( 17 ) or against the setting tool ( 15 ).
The top of the thermite ( 23 ) is shown enclosed by a cap ( 41 ). The firing head ( 17 ) can also include an outer cap ( 42 ), which is shown enclosing the power source ( 21 ) contained within, enabling the entirety of the pressure produced by the power source ( 21 ) to be contained for actuating a movable member, shown as a piston ( 43 ) within the setting tool ( 15 ), by directing the pressure produced by the power source ( 21 ) in a downhole direction. A thermal generator ( 27 ) is shown disposed in contact with the thermite ( 23 ) for initiating the thermite reaction. An electrical conduit (such as that depicted in FIG. 1 ), or a similar source of energy is usable to activate the thermal generator ( 27 ). A typical thermal generator can produce heat sufficient to ignite the thermite ( 23 ) responsive to electrical current. An exemplary thermal generator is shown and described in U.S. Pat. No. 6,925,937, the entirety of which is incorporated herein by reference. Usable thermal generators can include any source of heat for initiating the thermite reaction, including direct contact between heating elements and the thermite or use of a heat source in communication with a separate controlled quantity of thermite used to initiate the thermite reaction within the power source ( 21 ).
While the polymer ( 25 ) is shown having the structural form of a container or sleeve for containing or otherwise partially or wholly enclosing the thermite ( 23 ), the polymer ( 25 ) can be combined with the thermite ( 23 ) in any manner that permits the polymer ( 25 ) to produce gas responsive to the thermite reaction.
Thermite includes as a mixture of powdered or finely divided metals and metal oxides that reacts exothermically when ignited. The resulting thermite reaction is classified as non-explosive, the reaction occurring over a period of milliseconds, rather than nanoseconds. Specifically, thermite can include powdered aluminum, magnesium, chromium, nickel, or other similar metals, mixed with cupric oxide, iron oxide, or other similar metal oxides. In a preferred embodiment of the invention, the thermite ( 23 ) includes a mixture of aluminum and cupric oxide.
The polymer ( 25 ) can include any polymer or copolymer, including but not limited to polyethylene, polypropylene, polystyrene, polyester, polyurethane, acetal, nylon, polycarbonate, vinyl, acrylin, acrylonitrile butadiene styrene, polyimide, cylic olefin copolymer, polyphenylene sulfide, polytetrafluroethylene, polyketone, polyetheretherketone, polytherlmide, polyethersulfone, polyamide imide, styrene acrylonitrile, cellulose propionate, diallyl phthalate, melamine formaldehyde, or combinations thereof.
The quantity of polymer ( 25 ) within the power source ( 21 ) can be varied, in relation to the quantity of thermite ( 23 ), depending on the subsurface tool to be set. For example, when setting a packer, approximately 25% more polymer than thermite, by weight, can be used. In other embodiments of the invention, the quantity of polymer can range from 110% the quantity of thermite to 250% the quantity of thermite, by weight. It should be understood, however, that any quantity of polymer in relation to the quantity of thermite can be used, depending on the desired characteristics of the power source and the pressure to be produced.
In an embodiment of the invention, the power source ( 21 ) can also include an accelerant (not shown), such as magnesium, mixed or otherwise associated with the thermite ( 23 ) and/or the polymer ( 25 ).
In operation, electrical current is provided to the thermal generator ( 27 ), via the electrical conduit (depicted in FIG. 1 ) or using another similar source of power. once the thermal generator ( 27 ) reaches the ignition temperature of the thermite ( 23 ), the thermite ( 23 ) begins to react. Heat from the thermite reaction heats the polymer ( 25 ), which causes the polymer to produce gas, which is at least partially consumed by the thermite reaction, thereby slowing the reaction. Absent the polymer ( 25 ), the thermite would react rapidly, in a manner of seconds or less. Through use of the polymer ( 25 ) to attenuate the reaction, the thermite reaction can occur over several minutes, generally from one to three minutes. The gas produced by the polymer ( 25 ) further increases the overall gas pressure produced by the thermite reaction.
The gas from the polymer ( 25 ) and/or the thermite reaction, confined by the outer cap ( 42 ), breaches the bottom wall ( 31 ) to apply pressure to the piston ( 43 ), thereby actuating the subsurface tool ( 15 ). The thermite reaction is not temperature sensitive, thus, the power source ( 21 ) is unaffected by the temperature of the downhole environment, enabling a reliable and controllable pressure to be provided by varying the quantity of thermite ( 23 ) and polymer ( 25 ) within the power source ( 21 ). Through provision of a “slow set” to a packer or similar tool, such as a continuous pressure for a period of one minute or longer, elastomeric sealing elements obtain greater holding capacity than sealing elements that are set more rapidly.
Subsequent to the thermite reaction, the thermite ( 23 ) and polymer ( 25 ) can be substantially consumed, such that only ash byproducts remain. The quantity of thermite ( 23 ) and/or polymer ( 25 ) can be configured to vary the reaction rate and the pressure provided by the reaction. For example, the length of the firing head ( 17 ) can be extended to accommodate a larger quantity of thermite ( 23 ) and/or polymer ( 25 ) when a longer reaction is desired. Similarly, a longitudinal hole or similar gap can be provided within the thermite ( 23 ) to shorten the reaction time.
While various embodiments of the present invention have been described with emphasis, it should be understood that within the scope of the appended claims, the present invention might be practiced other than as specifically described herein. | A power source for applying a force to an object includes thermite in a quantity sufficient to generate a thermite reaction, and a gas producing substance disposed in association with the thermite. The gas producing substance produces a gas when the thermite reaction. The thermite reaction, the gas, or combinations thereof provide a force to the object. | 2 |
BACKGROUND OF INVENTION
The present invention relates to a method of identifying a plurality of transponders through an interrogation process, to an identification system comprising a plurality of transponders and at least one interrogator, to the transponders and to the interrogators themselves.
Radio Frequency Identification (RFID) systems frequently use collision arbitration, also known as anti-collision protocols, so that a plurality of RFID transponders, often referred to as tags, can be present and separately identified by an RFID interrogator (also known as a reader). There are a number of different types of protocol that can be adopted, the two most common of which are tree walking (using binary search or similar techniques) and random transmit and retry generally referred to as Aloha collision arbitration.
Examples of such systems are described by Marsh et al in U.S. Pat. No. 5,995,017, Palmer et al in U.S. Pat. No. 5,530,702 and Reis et al in EP0467036 and Reis et al U.S. Pat. No. 5,640,151, the whole contents of which are incorporated herein by way of reference. In all these known systems, a tag intermittently transmits an identification code or its identity in response to a signal, command or instruction from an Interrogator. The intermittent response is typically at random or pseudo-random intervals. In many embodiments of the subject invention the systems are such that the interrogator is not required to send commands or conduct a two-way dialogue with the tag or tags, however, the subject invention does not excluded such systems and indeed may be used with such systems. When a plurality of tags is present in the energising zone of an interrogator and if all tags transmit their identities in response to a signal from the interrogator, then tag transmissions may collide or clash. By randomly spacing tag transmissions the probability of collisions is reduced. However, the more tags that are present in the interrogator zone, the greater the repeat interval necessary to ensure that all tag identities are received by the interrogator without clashes of tag transmissions occurring. This problem is increased when the tag transmissions become longer, the longer the data packets the greater the likelihood of the tag transmissions clashing.
Tags are frequently required to carry an identification code as well as additional user encoded data. Also, tags and interrogators are frequently used in open systems where the well known method of data layers is used. The tag—interrogator data exchange and data definition layers are thus often separate entities with no shared knowledge. While the length of the tag ID (TID) may always be pre-determined there is no way to determine how much user data is encoded on the tag or is transmitted by the tag. Therefore the tag packet length could be either a variable length data packet or a fixed length packet with unused bits filled with null information, which is wasteful. It should also be noted that a TID is usually but not always defined in such a way to make it uniquely detectable as a TID data message.
One method used to transmit tag ID or data is to break the tag transmission (message) into a number of transmissions (which we call packets) of equal length and to only transmit the number of packets needed to convey the required data. There are two disadvantages to this method. The first is that the interrogator does not know how many packets to expect. The second disadvantage is potentially more serious. If the transmissions from two separate tags clash or overlap, the interrogator may receive a number of packets from a first tag and then when the first tag has sent its data the interrogator may receive one or more packets from a second tag whose transmission may have been slightly weaker and therefore overridden by the first tag transmission. The interrogator has no way to determine whether all the packets originated from a first tag or that they erroneously originated from a first tag followed by a second or even third tag. Interrogators thus normally need to receive a tag transmission multiple times before deciding it is correct, or have knowledge of the data payload; this is often not practical. A packet, as part of a long transponder transmission, may even not be recognised because of RF noise or collisions. This will result in the interrogator believing that it received two or more transmissions from transponders.
SUMMARY OF THE INVENTION
Accordingly, the invention seeks to eliminate or reduce the aforementioned problems.
According to an aspect of the present invention there is provided a method of identifying a plurality of transponders, the method comprising receiving at a interrogator one or more data transmission blocks from each transponder, wherein the first data block contains a uniquely detectable transponder identity and zero or more further data blocks defining a set of data blocks making up a transponder transmission.
In one embodiment the method comprises uniquely combining the chain of data transmission blocks into a single transponder transmission, the single transponder transmissions received at the interrogator may be of variable length and a plurality of transponders may be transmitting in the same time space.
According to a further aspect of the present invention there is provided a method of identifying a plurality of transponders, the method comprising receiving at a interrogator a chain of data transmission blocks from each transponder, wherein the first data transmission block contains a transponder identity and a transmission block number; one or more further data transmission blocks containing additional block data and a respective transmission block number; the block number being changed automatically as each data block is transmitted.
In one embodiment of the invention each data transmission block contains an error checking code.
In a further embodiment the transmission block number is derived from a counter in the transponder, the block number being decremented automatically as each data block is transmitted. Alternatively, the transmission block number may be derived by the block number being incremented automatically as each data block is transmitted. It will be appreciated that the exact sequence of block number change, whether by decrement, increment or combination thereof, for each data transmission block that makes up a single transponder transmission may take a variety of forms with the end result that the interrogator can determine when a single transmission has been received.
In an embodiment the method of identifying a plurality of transponders comprises transmitting a power or interrogation signal to the transponders and receiving response signals from the transponders, each response signal comprising a chain of data transmission blocks; the first transmission containing a transponder identity and further contains a transmission block number derived from a counter in the transponder; one or more further data blocks containing additional block data and a block number; the block number being changed automatically as each data block is transmitted and each data block containing an error checking code.
In one embodiment each data block, which may also be referred to as a data packet or page, is appended a down-counter number indicating the number of blocks to follow and a CRC calculated to include the down-counter number. Thus the interrogator always knows how many data blocks are to follow and also can detect the first data block. It thus has the ability to detect part of the start of a transponder transmission and successfully detects the completion of a transponder transmission or the interruption of a transponder transmission. Although in this embodiment a down-counter number is employed it will be appreciated by those skilled in the art that an up-counter may also be employed, the crucial factor being that the interrogator is informed as to how many data blocks are to be received.
After the interrogator detects the first data block using the uniquely identifiable tag identifier (TID), the interrogator detects the number of pages (data blocks) making up the full transponder transmission whereby the interrogator can reserve space for the set of data blocks, making up the transponder transmission, and fill it in as received. Specific data blocks may not be received or may be wrong as indicated by the CRC; the receiver will leave those blank. The method in accordance with an embodiment of the invention will then use a second transmission to fill in the gaps, even if this transmission also contains wrong data blocks.
In a further embodiment of the invention there is provided a further method of linking data blocks of a transmission. The method comprises using a CRC calculation in a data block which also includes the CRC of the previous data block, with the first packet using a NULL value as the previous data block. The interrogator now can also detect the first data block by using this method thereby enhancing the detection integrity and integrity of the chain of data blocks.
According to a further embodiment of the invention there is provided a method whereby the interrogator, on detection of too many collisions or RF noise, instructs the transponders to change their random number patterns. Furthermore, a tag may adapt its random number pattern in response to the number of clashes detected in a multi-tag environment.
It is known that in an Aloha collision arbitration method employed for transponder transmissions from a plurality of transponders, the transmissions may be of variable length using a plurality of fixed length data packets, separated by a time gap. The first page contains a TID detectable by the data format of the TID and a CRC which forms part of the data of the TID. In a specific application the data packets contain 64 bits of data and the data packet is preceded by 8 preamble bits. The packets are separated by 8 bits in time. In one specific embodiment of the present invention there is appended at the end of each data packet a 3 bit down-counter value and a 5 bit CRC. The interrogator can detect the first page using the TID and determine from data on that first page the number of packets to be received. The interrogator can then detect the intermediate packages and detect their position in the chain and also verify the data packet correctness using the 5 bit CRC. The interrogator then detects the last packet and verifies the data packet correctness using the 5 bit CRC. It is clear that the interrogator may now, in accordance with an embodiment of the invention, use partial transmissions to build up a complete transmission even when never receiving a complete transmission.
An enhancement of the later embodiment is by calculating the 5 bit CRC on the previous CRC, the data and the down-counter. The interrogator now has the ability to detect to which transponder transmission a rogue data packet belongs. This aids the interrogator further to decode a complete transponder transmission in very noisy RF environments.
In one embodiment the transponder or tag, when entering an energising field or signal from an interrogator or reader, may power up into a powered-up state, whereupon the tag waits for a predetermined period, and if at the end of said predetermined period the tag has not detected any modulation in the interrogator signal, the tag will start a random timer within the tag which determines an overall period before the tag enters its transmitting state, the transmitting state being that at which the tag transmits its data message in the form of the chain of data transmission blocks.
In one embodiment the tag reverts back to its powered state after it has transmitted its data message.
In one embodiment, after the execution of a valid command the tag reverts to its powered-up state whereupon it follows a protocol of executing a random internal waiting period before transmitting its message.
In a further aspect of the invention there is provided an identification system comprising an interrogator and a plurality of transponders, the interrogator including a transmitter for transmitting an interrogation signal to the transponders, each transponder including a receiver for receiving the interrogation signal, a transmitter for transmitting a response signal, the response signal comprising a chain of data transmission blocks; the first data block containing the transponder identity and a data block number; one or more further data blocks containing additional block data and a data block number; the block number being changed automatically as each data block is transmitted.
In one embodiment each data packet contains an error checking code.
The block number, which may be derived from a counter in the transponder, can be incremented, decremented or otherwise altered whereby the interrogator or reader can determine when it has received a single transmission from the transponder.
In a yet further aspect of the invention there is provided a transponder, the transponder including a receiver for receiving an interrogation signal from an interrogator, a transmitter for transmitting a response signal after receipt of the interrogation signal, the response signal comprising a chain of data transmission blocks; the first data transmission block containing the transponder identity and further containing a transmission block number derived; one or more further data blocks containing additional block data and a block number; the page number being incremented or decremented automatically as each data block is transmitted.
In one embodiment each data block contains an error checking code.
The transponder may be provided with a counter for changing the block number.
In a further aspect of the invention there is provided an integrated circuit for use in a transponder including a receiver for receiving an interrogation signal, a transmitter for transmitting a response signal after receipt of the interrogation signal, the response signal comprising a chain of data transmission blocks; the first data block containing the transponder identity and further containing a data block number; one or more further data blocks containing additional block data and a block number; the block number being changed automatically as each data block is transmitted.
In one embodiment each data block contains an error checking code.
The integrated circuit may be provided with a counter for changing the block number.
In a further aspect of the invention there is provided an interrogator for identifying a plurality of transponders, the interrogator comprising a transmitter for transmitting an interrogation signal to the transponders and a receiver for receiving response signals from the transponders wherein the interrogator is adapted to identify the transponders from response signals comprising a chain of data transmission blocks; the first data block containing the transponder identity and further containing a block number; one or more further data blocks containing additional block data and a block number; the block number being changed automatically as each data packet is transmitted.
In one embodiment each data block contains an error checking code.
The interrogator may comprise a counter for counting the chain of data transmission blocks received, and a comparator to determining when the number of packages received corresponds to the full data message having been received from the transponder.
In a yet further aspect of the invention there is provided a computer program product operable, when executed on a computer, to perform the method defined above. The product may be implemented as a storage medium, the storage medium comprising one or more from the group consisting of a memory device or a hardware implementation such as an ASIC.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a simplified representation of prior art transducer data transmissions;
FIG. 2 is a simplified representation, similar to that of FIG. 1 , with a difference illustrating a further problem that arises with the prior art transmissions;
FIG. 3 is a simplified block diagram showing an interrogator and three transponders according to prior art arrangements;
FIG. 4 is a flow diagram illustrating the various operational states of a transponder in accordance with one embodiment of the invention;
FIG. 5 is a simplified data representation of a transponder transmission consisting of N+1 pages of user data with a down-counter number and CRC appended;
FIG. 6 is a simplified diagram showing how an interrogator may complete a transponder transmission using incomplete transmissions and
FIG. 7 is a simplified data diagram showing the calculation of the CRC including the previous page's CRC, the first pages using a NULL value.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description, specific implementations of the invention are described. It will be appreciated by the reader that these are provided by way of example only, and are not intended to provide restriction or limitation on the scope of the invention which is defined in the appended claims.
FIG. 1 illustrates the random or pseudo-random nature in which data packets are transmitted from four tags, and in the case of tag 1 it is only on the fourth transmission T 14 of its data packet that no clashes between transmissions occur at the receiver. It is only on the fourth transmission T 14 from tag 1 that the data packet of tag 1 can be read correctly by an interrogator. In the instances when clashing of signals occurs at the interrogator, the received signal is corrupted and the corruption is detected by the interrogator.
However, the detection in corruption of a received signal at the interrogator is dependent on various factors such as the format of the overlapping signals, signal strength and duty cycle. For example, if the data packet from each tag is split into a number of smaller data packets of equal length, defining a concatenated format, the overlapping, clashing concatenated package parts (or pages) may be mistaken at the interrogator as being transmitted by the same tag, and the non-overlapping parts (or pages) may also be read at the interrogator as being from the same tag thereby providing erroneous information as to the data package.
FIG. 2 illustrates the data transmission packets shown in FIG. 1 with the single change that a further data packet T 23 is transmitted randomly from tag 2 , which, although not overlapping T 14 , directly follows T 14 . In this instance, even if previous clashes of concatenated data packets from the different tags have been previously recognised as such by the interrogator, the two data packets T 14 and T 23 may still erroneously be read together as being one data packet originating from tag 1 .
FIG. 3 illustrates an RFID system, typically used in the prior art, the system comprises an interrogator 10 , including a transmitter 11 with a transmitting antenna 11 a and a receiver 12 with a receiving antenna 12 a . The transmitter ( 11 , 11 a ) transmits a powering signal (interrogator signal) to a number of passive transponders (tag 1 , tag 2 and tag 3 ).
Each transponder includes an antenna, the two antenna poles 4 and 5 . The transponders within the interrogator field are able to derive a power supply from the energy in the interrogator signal using a capacitor C and a diode D. A code generator 6 and logic circuit 7 generate a signal using a predetermined coding, which is transmitted to the interrogator 10 , by modulating a portion of the energy received from the interrogator 10 using a modulator 9 connected to the antenna poles 4 and 5 .
The transponders are provided with local timing means. Looking at the operation of the system of FIG. 2 in more detail, on receiving power each transponder executes a random wait cycle before transmitting its code signal as a data packet (or page). In one embodiment if the interrogator detects too many clashes are occurring, the interrogator may transmit an instruction for the transponders to alter their maximum random waiting time. Upon successful receipt of a transponder code signal, the interrogator 10 transmits an acknowledgement signal that disables that transponder.
More particularly, and in accordance with one specific embodiment of the invention, one or more of the tags 1 , 2 and 3 in FIG. 3 may have a data memory of 256 bits of data arranged as 4 pages each of 64 bits. The first page contains tag data shown below as IDn followed by an indicator providing the number of pages p and a cyclic redundancy error check code. The first packet transmitted is a standard identification page with a format recognisable to the interrogator. The second and subsequent packets transmitted each contain the next block of tag data followed by a page indicator followed by an error check code.
A “1” page message, employing a down counter, is constructed as a packet containing the elements:
[ID][0][CRC]
with ID the identification page of the tag message
with [0] down counter number indicating that no more pages are to follow, and
with CRC the CRC of the page
A 5 page message, employing a down counter, will be constructed as 5 concatenated packets containing the elements:
[ID][4][CRC 1 ]|[D 1 ][3][CRC 2 ]|[D 2 ][2][CRC 3 ]|[D 3 ][1][CRC 4 ][D 4 ]|[D 4 ][0][CRC 5 ]
with ID the identification page of the tag message
with D M data page M of the tag message
with [x] a down counter indicating the number of pages to follow.
with CRC N the CRC of the page N
The page counter serves two functions, first it indicates the page's original value and secondly it provides the interrogator with an indication of how many pages to expect from the tag. By providing an error check code at the end of each tag page and therefore each transmitted tag packet the error check code in addition to validating the data content of the packet also validates the page number indicator.
In the case of a down counter, by example, the page counter is initially set to the number of data pages to be transmitted and is decremented each time a page is transmitted so that it always indicates the number of pages to follow. The last page transmitted will have the data value of 0. In an alternative embodiment the page counter can be incremented up to a desired page value. In this case the ID page may contain the number of data pages and each on of the data pages are number to its position in the chain. A 5 page tag message will then look as follows:
[ID][4][CRC 1 ]|[D 1 ][1][CRC 2 ]|[D 2 ][2][CRC 3 ]|[D 3 ][3][CRC 4 ]|[D 4 ][4][CRC 5 ]
Thus, if two tag transmissions overlap but are not completely synchronised with each other, and if the interrogator receives the transmission from the strongest tag transmission first it will stop decoding when it receives the last packet and will ignore any further packets received.
The tag to interrogator transmission makes use of the known propagating wave backscatter technique. In the specific embodiment the tags are UHF RFID tags and interrogators, however it will be appreciated, tags and interrogators operating in other frequency ranges or using other coupling means such as wave propagation, reactive coupling such as magnetic coupling or capacitive coupling can also be used for carrying out the invention.
The tags transmit their data packets at random or pseudo-random intervals for the purpose of employing unslotted Aloha collision arbitration. Whereas unslotted Aloha is a preferred form of transmission for many tag to interrogator applications, the invention can also be adapted for use with slotted Aloha transmission between the tag and interrogator.
In the specific embodiment described here the interrogator (or reader) does not have to issue a talk command to the tags, it being sufficient for the interrogator to merely transmit an unmodulated carrier signal which supplies the power to the tag. The tag then entering a wake up mode, and after a slight delay, automatically switches into a transmit mode whereby it implements a pseudo-random Aloha transmission of its data packets. It will be appreciated that should the interrogator wish to write to or program a tag, that tag can be provided with a suitable receiver and/or command decoder.
Looking at the RFID communication protocol of the specific embodiment in more detail, a tag will first enter an energising field of an interrogator and when the field, at the tag, reaches a strength above a predefined value, the tag will power up and begin the transmission sequence of its data packets as described above.
As referred to earlier an unmodulated carrier wave from the interrogator is sufficient for the power-up of the tag. Any modulation in the carrier signal may indicate communication occurring between the interrogator and a tag, for example the interrogator may send a signal to the tag when it has successfully read its data packet and wishes to mute that tag, and will do this by modulating its carrier wave or transmitting a second signal.
Accordingly, in one embodiment the tags monitor for any modulation for a predefined period and if any modulation is detected in the interrogator's signal, the tag suspends the backscattering of its data packets. When the interrogator signal reverts to pure carrier wave, the tag waits for a random delay time, with a maximum delay time value, and then backscatters its message. In between backscattering its data packets, the tag may continuously monitor for modulation on the energising carrier signal.
In the description above the tag derives its power from the energising field, the incident energy being rectified and smoothed power the circuits. Alternatively the tag may be provided with a battery to facilitate the powering of the tag. The tag can still use backscatter modulation for transmitting its message. Furthermore, when a tag uses a battery to assist its circuits, it may incorporate a signal detection circuit to detect the presence of an interrogator transmission or carrier wave and use the resulting signal detection to cause the tag to transmit its message.
The various states in which a transponder operates is illustrated in a specific embodiment shown in FIG. 4 , it will be appreciated the transponder can operate in many other configurations and is in no way limited to the implementation to be described below with reference to FIG. 4 .
A transponder starts in an OFF STATE until it finds itself in an energising field provided by the interrogator, the energising field being of a sufficient strength to wake up the tag, the tag will then power up into what is shown in FIG. 4 as the POWER state.
When the tag is in thePOWER state there are various operational modes for the tag. In the first mode the tag waits for a predetermined period, typically a few milliseconds, and if at the end of this short period it has not detected any modulation in the interrogator signal it will start a random timer within the tag which determines the overall DELAY period before entering its TRANS state, the TRANS state being that at which the tag transmits its data message in the form of a series of concatenated data packages.
After sending its message in this way, the tag reverts back to the POWER state and if it detects modulation in the interrogator of a specific nature will pass either into the QUIET or COMMAND state. The tag may determine the modulated signal from the interrogator as acknowledging the tag's message has been successfully received and the tag can then pass into the QUIET state where it is muted for a defined period before passing to the OFF state when the energising field is removed. Alternatively the modulation in the interrogator signal may indicate communication between the interrogator with another tag, in which event the tag still passes into the QUIET state where it may detect a power reset command or another valid command to change it into the COMMAND state. When in the COMMAND state the tag suspends the transmission of its messages and executes any valid command from the interrogator, and after the execution of that command may revert to the POWER state whereupon it follows the protocol of executing a random internal waiting period before transmitting its message.
In the above manner the tag will implement an RFID protocol in accordance with one specific embodiment of the present invention.
FIG. 5 is a simplified data representation of a transponder transmission consisting of N+1 pages of user data with the down-counter number and CRC appended. The first page, or data block, provides a transponder identity TID followed by the number of data pages N in the transmission and the CRC for that data block. The next data block provides user data with an indication of the changed data block number, now N−1, and a further CRC. This process is continued until the final data block is received at the interrogator, indicated by data block number zero followed by a CRC.
FIG. 6 is a simplified diagram showing how an interrogator may complete a transponder transmission using incomplete transmissions. In the example shown the transponder transmission consists of four data blocks. After the first data transmission the interrogator has correctly identified the first, second and fourth data blocks but has disregarded the third as it may have been involved in a collision or is otherwise corrupted. The interrogator therefore waits for the second transmission from the same transponder, in this case the interrogator has correctly identified the first, third and fourth data block in the transmission, it can therefore incorporate the second data block into its memory thereby assembling the complete transmission from the transponder.
FIG. 7 is a simplified data diagram showing the calculation of the CRC including the previous page's CRC, the first page using a NULL value. The method comprises using a CRC calculation in a data block which also includes the CRC of the previous data block, with the first packet using a NULL value as the previous data block. The interrogator now can also detect the first data block by using this method thereby enhancing the detection integrity and integrity of the chain of data blocks. | A method of identifying a plurality of transponders, the method comprising receiving at an interrogator one or more data transmission blocks from each transponder, wherein the first data block contains a uniquely detectable transponder identity and zero or more further data blocks defining a set of data blocks making up a transponder transmission. The first data transmission block also contains in transmission block number; one or more further data transmission blocks containing additional block data and a respective transmission block number; the block number being changed, by decrement or increment, automatically as each data block is transmitted. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is derived from provisional application 60/078,312, filed Mar. 17, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrical switching device utilizing a frangible actuator, specifically to a device for bypassing (i.e., isolating) a failed battery cell utilizing an improved frangible actuator.
2. Description of the Related Technology
A multi-cell battery typically has the cells connected in series so that their voltages will be summed to produce a battery with a higher voltage than could be obtained with a single cell. Unfortunately, when a battery cells fails, it generally develops a high resistance. Since this resistance is in series with the other cells, it effectively disables the entire battery, even though the remaining good cells would be sufficient to keep the battery operating in a slightly degraded mode. For large batteries, where battery cost is high and replacement is difficult, it makes sense to use actuators to detect and isolate failed cells so that the battery can keep operating. Since a defective cell generally cannot be repaired, such actuators are generally one-way single-use actuators, and can be frangible (i.e., they activate by separating).
Conventional actuators (used for a variety of purposes) have a number of deficiencies. For the switch portion, a commonly-used structure provides a conductive tube with the end slightly bent in. A slightly smaller conductive cylinder fits within the tube so that it just touches the inwardly indented portion of the tube's rim. A second tube with a similarly indented end faces the first. Upon activation, the cylinder passes into the second tube, contacting its rim and providing an electrical connection between the two tubes. Unfortunately, such devices can only be used as simple on-off switches. In addition, they provide a minimal contact area, which limits the amount of occurrent that can be conducted. Also, the degradation of contact force due to heating is reduced.
Another problem with conventional actuators is that they employ frangible cylinder-type actuators, which are prone to mechanical failure, due to the manner in which certain portions can interfere with other portions during actuation. An actuator is needed that maintains the simplicity of conventional actuators, but with improved reliability and higher current capacity.
SUMMARY OF THE INVENTION
A frangible actuator may contain a plurality of separable parts, preferably in the form of two cylinder halves pressed together to form an overall cylinder shape. The cylinder halves may be held together by wrapping a restraining wire around them multiple times, and securing the ends of the restraining wire so that it stays in this position. One end of the restraining wire may be secured to one of the separable halves, while the other end may be secured by a sensor that detects when an electrical current exceeds a predetermined threshold. The sensor is preferably a fusible link which melts, separates, deforms or otherwise fails in tension when the current through it exceeds the threshold, thereby releasing the end of the restraining wire. Once the restraining wire is released, the cylinder halves may be free to separate.
A spring-loaded plunger may be held in place by the cylinder halves in their restrained position, with the end of the plunger pressed against a conical surface formed between the two halves. When the cylinder halves are allowed to separate, the force of the plunger against this conical surface may force the cylinder halves apart, allowing the plunger to continue moving forward between the cylinder halves until stopped by a physical obstacle. This motion of the plunger may activate a switch.
The sensor may be attached to an insulator at one end of the cylinder, so that the electrical connections to the sensor are held away from the cylinder halves to avoid physically interfering with them during separation. The insulator may also include two pins disposed between the cylinder halves to prevent them from rotating under the urging of the restraining wire, which can be made of a spring-like material and be spring loaded in its restraining position.
The actuator can activate an electrical switch. The switch may include a contact base formed as a conductive cylinder which slides axially within the bore of multiple electrical terminals. By attaching the contact base to the end of a non-conductive cylinder of the same diameter, the total conductive/non-conductive cylinder may slide within the terminal bores, making or breaking contact with each terminal according to which portion of the cylinder is within that terminal. Reliable electrical contact may be achieved by placing toroidal contact elements within annular grooves in the conductive cylinder. Each contact element may be in the form of a coiled spring with its two ends attached to each other, thus forming a toroid having a spiral spring traversing the circle of the toroid. By sizing the various elements so that outermost portions of the toroid are slightly larger than the diameter of the terminal bore, the contact element may be slightly compressibly deformed when within the terminal bore, thus creating a spring-loaded force at each contact point. Switches formed in this manner may be configured with one or more poles, single- or double-throw, make-before-break or break-before-make, or any combination of these, simply by changing the number and spacing of contact elements and the spacing between terminals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a-c show a section of the invention in various positions respectively in a pre-activated state, a transitional state and a post-activated state. FIG. 1 a ′ is a cross-sectional view of the invention taken along line 1 a ′— 1 a ′ of FIG. 1 a . FIG. 1 a ″ is an end view taken from the end opposite to that shown in FIG. 1 a ′ of the invention depicted in FIG. 1 a.
FIGS. 2 a-b show the circuitry of the invention respectively before and after actuation.
FIGS. 3 a-c show details of the actuator illustrated in FIG. 1 a , in which FIGS. 3 a and 3 b are taken orthogonally to one another.
FIGS. 4 a-f shows various alternative configurations of the switch depicted in FIGS. 2 a and 2 b , in which FIG. 4 a switch is a double-pole single-throw switch, the FIG. 4 b switch is a single-pole double-throw switch, the FIG. 4 c switch is a single-pole double-throw switch, the FIG. 4 d switch comprises two separate single-pole single-throw switches, the FIG. 4 e switch is a single-pole single-throw switch, and the FIG. 4 f switch is a double-pole switch with one pole being single-throw and the other being double-throw.
DETAILED DESCRIPTION OF THE INVENTION
The invention can be a one-shot or single-use device which, upon application of a predetermined electrical stimulus, provides at least one closed and/or open switch connection. Depending on the arrangement of the switching elements, a preferred embodiment of the switch may be configured as a single-pole single-throw or a single-pole double-throw switch. Contacts may be configured in a make-before-break or break-before-make arrangement. Ganged and multiple switch designs are also possible.
Switch Assembly
FIG. 1 a ′ and 1 a ″ show the battery cell bypass with frangible actuator, in an embodiment adapted for a single-pole double-throw switch. As can be seen, in the “before activation” position, the circuit between terminal T- 1 and terminal T- 2 is closed by conductive contact base 30 , whereas the circuit between terminal T- 2 and terminal T- 3 is opened by non-conductive base 32 . FIG. 1 b shows the frangible actuator opening, allowing the plunger 14 (generally a dielectric plunger with a conductive tip) to be urged forward by compression spring 18 . Terminals T- 1 , T- 2 and T- 3 are all shown connected in a make-before-break mode. As the compression spring urges the plunger after forward to its final position, FIG. 1 c shows the circuit between terminals T- 1 and T- 2 has been opened and the circuit between terminals T- 2 and T- 3 has been closed, completing the operation. Improved electrical contact between contact base 30 and the terminals can be achieved by the use of coiled springs 25 , 27 , 29 and 29 a formed in a toroidal shape. Although FIG. 1 a shows a preferred embodiment employing two pairs of coiled springs 25 , 27 and 29 29 a, other combinations may also be employed for specific applications, such as two single coiled springs (not shown) replacing the two pairs shown ( 25 , 27 and 29 , 29 a ) or one pair of coiled springs 25 , 27 and a single coiled spring (not shown) replacing paired springs 29 , 29 a. Other configurations are also useful, again depending on the specific application.
FIG. 1 c also shows a cross section of the actuator/switch assembly 1 in its pre-actuated condition. In a preferred embodiment, cylindrically-shaped housing 12 can provide physical support for plunger 14 , non-conductive base 32 , and contact base 30 . Plunger 14 , base 32 and contact base 30 may be effectively attached to each other so that they move as a single unit in a longitudinal direction within housing 12 , and this movement may provide the switching action. Contact base 30 may be made of electrically conductive material, with contacts elements 25 , 27 and 29 , 29 a providing dependable electrical contact between contact base 30 and electrical terminals T- 1 , T- 2 , and T- 3 . In a preferred embodiment, contact elements 25 , 27 and 29 , 29 a encircle contact base 30 in recessed annular grooves, and make contact with an inside surface of a circular bore within terminals T- 1 , T- 2 , T- 3 . This “full circle” contact area provides for a large contact surface, permitting the switch to carry more current than it could with a single-point contact area. In a preferred embodiment, contact elements 25 , 27 and 29 , 29 a toroidal springs, which can be formed by connecting the two ends of a standard spiral-coiled spring together so the spring assumes the overall shape of a toroid. The various elements of the switch may be sized so that the outer diameter of the toroid is slightly larger that an annular contact surface of a terminal, thereby compressing or deforming the contact element when it is moved into contact with the terminal. The spring-like resistance of the contact element may thus be used to assure good contact at each point. This shape can provide a separate contact point with the terminal for each turn of the spiral in the contact element spring, thereby creating many contact points. With the current flow thereby distributed over a larger area, current density at any given point can be maintained at a lower level, with a corresponding reduction in heat generation and an increase in the surface area for dissipating the heat. This configuration also improves reliability, since poor contact at any given point (due to corrosion, physical defect, etc.) is essentially in parallel with many other good contact points, and thus has little effect on overall current flow.
FIGS. 1 a, 1 b, and 1 c show the sequence of movement during an activation cycle. In the pre-activated state of FIG. 1 a, terminal T- 1 is electrically connected to terminal T- 2 through contact elements 29 and 29 a, contact base 30 , and contact elements 25 , 27 . As contact base 30 moves to the left (as left is depicted in the drawing), terminals T- 1 , T- 2 , and T- 3 are all connected together in the transitional state of FIG. 1 b. This is a make-before-break configuration, since a new connection is made with terminal T- 3 before the old connection with terminal T- 1 is broken. A break-before-make switch could be configured by spacing T- 1 and T- 3 farther apart, so that they are never connected to T- 2 at the same time. FIG. 1 c shows the post-activated state, in which terminal T- 2 is connected to T- 3 through contact elements 29 and 29 a, contact base 30 , and contacts 25 , 27 .
Another advantage of the toroid-spring contact elements is that all the forces required to assure electrical continuity are contained within the contacts themselves, and therefore are not reliant upon any external members or features to react upon.
Although FIGS. 1 a-c show a single-pole, double throw, make-before-break switch, other configurations can be easily incorporated. Additional poles can be implemented by adding more contact bases 30 , electrically isolated from each other, if separate electrical circuits are to be switched. Single/double throw operation can be implemented simply by changing the quantity of the contact elements and associated terminals. Break-before-make or make-before-break can be implemented by simply changing the spacing between contact elements. FIGS. 4 a-f show several different switch types which might be implemented. In each figure, the two terminals at the bottom of the figure represent the fusible link (which may take the form or a fusible link wire), while the remaining terminals represent the switch terminals. FIG. 4 a shows a double-pole single-throw switch, FIG. 4 b a single-pole double-throw switch, FIG. 4 c a single-pole single-throw combined with a separate single-pole double-throw, FIG. 4 d shows two separate single-pole single-throw switches, FIG. 4 e has one single-pole single-throw switch, and FIG. 4 f double-pole switch with one pole being single-throw and the other double-throw.
Regardless of the switching configuration, the necessary force for the switching action may be provided by spring 18 , which is normally constrained from motion because plunger 14 is prevented from moving by frangible actuator 10 . When actuator 10 is split into two halves as shown in FIG. 1 b, plunger 14 is free to move between the two halves, and the force of spring 18 can urge plunger 14 , non-conductive base 32 , and contact base 30 toward insulator 65 as shown in FIG. 1 c.
Actuator
The actuator may be an enabling device that initially restrains a coaxially located shaft from axial movement, but releases the restraint upon application of a predetermined minimum amount of electrical current. The actuator includes a fusible link, which may include any resistive material that decreases its tensile strength in response to an increase in temperature. In a preferred embodiment, the fusible link is a length of 18-8 stainless steel wire. The actuator also includes a restraining wire, an insulator assembly, and two cylinder halves. A preferred embodiment may use several mechanical advantages to multiply the holding capability of the fusible link, such as inclined planes or cones, and multiple wraps of a restraining wire. Reliability may be improved by using anti-rotation pins, and by connecting the fusible link to a non-moving part. A current sensor, such as the fusible link, may be used to hold the restraining wire in place during normal operation, but release the restraining wire when an overcurrent condition is detected. The fusible link may be made of high-strength, corrosion-resistant, heat-resistant material with a length and diameter sufficient to create the necessary thermal and electrical effects. In a preferred embodiment, the fusible link may have an electrical resistance of about one ohm, and a diameter large enough to continuously dissipate the heat generated by a predetermined-maximum current (in one embodiment, one amp) but small enough to heat past its stress-failure point if the current exceeds that predetermined maximum. When the fusible link temperature exceeds its stress-failure point, it can release the restraining wire, which in turn may release the mechanical components of the actuator. In a preferred embodiment, stress failure is characterized by melting, separation or other tensile failure of the fusible link.
FIGS. 3 a- 3 c show a preferred configuration of actuator 10 in greater detail. As shown, the two halves 62 , 64 of a cylinder-shaped device may be bound together by multiple wraps of a restraining wire 50 . Restraining wire 50 may be secured at one end to one of the cylinder halves, and restrained at the other end by fusible link 46 . Fusible link 46 may be terminated at either end by electrical terminals T- 4 and T- 5 . These terminals may be attached to insulator 65 through pre-formed holes. Access to the terminals by fusible link 46 may be acquired through access holes 67 . Conventional devices typically attach the fusible link to one of the cylinder halves, where the fuse terminals or connecting wires could get caught in the uncoiling restraining wire and jam it, preventing actuation. By placing the fusible link on the non-moving, non-frangible insulator as shown, the present invention prevents this problem by keeping all such components away from the uncoiling restraining wire 50 and the moving cylinder halves 62 , 64 .
When bound together as described, cylinder halves 62 , 64 may form a pyramid-shaped or cone-shaped recess 68 at one end. In the non-actuated position shown in FIG. 1 a, plunger 14 may be pressed into this recess, where it tries to force cylinder halves 62 , 64 apart with the insertion force provided by spring 18 . But since the two cylinder halves are tightly bound together by restraining wire 50 , this force may be unable to cause separation.
When a stress failure of fusible link 46 occurs, it can release the end of restraining wire 50 , which in turn releases cylinder halves 62 , 64 , allowing them to separate. The force of plunger 14 against recess 68 may force cylinder halves 62 , 64 apart, allowing plunger 14 to penetrate between the cylinder halves until it is stopped by recess 66 in insulator 65 . In a preferred embodiment, restraining wire 50 may be made of spring-like material, which in its unrestrained state is either straight or has a curvature larger than in its restrained state. When such a wire is released, it may “uncoil” from the cylinder, thus releasing the two cylinder halves. The interior walls of housing 12 can prevent the unrestrained wire from flying out too far and possibly interfering from with other parts of the device. In an alternate embodiment, restraining wire 50 may simply be flexible wire without the “memory shape” characteristics of a spring, and may be forced to uncoil simply by the force of plunger 14 separating the two cylinder halves. This configuration may require greater force from plunger spring 18 , since it must overcome the friction of restraining wire 50 against the cylinder halves.
Since a spring-loaded restraining wire 50 can impart a twisting force on the cylinder, cylinder halves 62 , 64 must be prevented from rotating and thereby unwinding wire 50 , causing the actuator to inadvertently actuate. This prevention may be accomplished with pins 70 , 72 inserted between the cylinder halves and attached to insulator 65 . As shown in FIG. 3 c, these pins can prevent cylinder halves 62 , 64 from rotating but do not impede separation. Since plunger shaft 14 fits between the two pins, the pins also prevent the cylinder halves from interfering with the plunger during actuation. Conventional devices typically place the cylinders in a recess in the insulator, where frictional forces between the cylinder half and the insulator can impede the separation motion.
Fuse terminals T- 4 and T- 5 are shown as conductive posts, with fusible link 46 shown as a short piece of wire connected between terminals T- 4 and T- 5 . Referring to both FIGS. 2 a and 3 a, as the cell fails and current flowing through diode 44 or 45 (or as noted below, other voltage sensitive electrical component) exceeds the diode threshold limit, such current is sufficient to heat and cause tensile failure of the fusible link 46 . Restraining wire 50 is normally held in place by having its end 51 hooked over fusible link 46 . When fusible link 46 fails in tension, hook end 51 is released, and restraining wire 50 is allowed to uncoil, thus allowing the two cylinder halves 62 and 64 to separate. Referring back to FIG. 1 a, prior to separation, initiator segments 62 , 64 in their closed position restrain the movement of plunger 14 . As shown in FIG. 1 b, when the restraining effect of restraining wire 50 is removed, plunger 14 is urged forward by spring 18 , causing cylinder halves 62 , 64 to be spread apart by the force of plunger 14 against angled recess 68 (see FIG. 3 b ). Once cylinder halves 62 , 64 are open sufficiently wide, plunger 14 may continue moving forward essentially without resistance, until plunger 14 encounters end 66 of the bore, as shown in FIG. 1 c.
The time it takes for the actuator to actuate is the sum of the time it takes fusible link 46 to melt or otherwise fail in tension, and the time for the mechanical parts to complete their motion. In a preferred embodiment, this total time is a few milliseconds. Variation in this time may be primarily due to the actuating current, which dictates how long it takes fusible link 46 to heat up and fail in tension. The time should be consistent for any given actuating current.
Although the cylinder halves are so named because of their shape in a preferred embodiment, they might assume various other geometric shapes as well, and there might be more than two such parts. An important consideration is that their shape and quantity permit the uncoiling of the restraining wire during actuation.
Circuit
FIGS. 2 a and 2 b show how the device is used in the context of a battery cell bypass. FIG. 2 a schematically shows bypass circuit 42 attached to a battery cell # 2 in which all cells are functioning. As can be seen, the cells are connected in series, so that if one cell fails by developing high resistance (the normal failure mode for a cell), the entire battery fails, even though all other cells may be functional. In a preferred embodiment, a bypass switch and sensor mechanism includes a voltage detector, such as diodes 44 , 45 , for detecting a voltage drop across a battery cell. Diodes 44 , 45 may be connected in parallel and together connected in series with a fuse, actuator, or other current-activated cutoff device, such as fusible link 46 (FIG. 3 a ) between terminals T- 4 and T- 5 . Fusible link 46 is adapted for triggering switch 47 , which has terminals T- 1 , T- 2 and T- 3 , and is connected between cell # 1 and cell # 3 . In normal operation as shown in FIG. 2 a, diodes 44 , 45 block current flowing in either direction unless the voltage drop across the diodes exceeds the small threshold value of the forward-biased diode. As long as the impedance of the diodes is much greater than that of the battery cell, most of the current will flow through the cell rather than the diode. Using two diodes with opposite polarity allows the sensor to operate with either battery polarity.
Each diode therefore effectively functions as a conductor in one direction and a high resistance insulator in the other direction, causing most of the current from cell # 1 to travel through cell # 2 to cell # 3 . FIG. 2 b shows that in the event of a failure of cell # 2 , most of the current from cell # 1 (which is greater than the threshold limits of the diodes) cannot pass through the high resistance of cell # 2 and therefore passes through the diodes and through fusible link 46 . When fusible link 46 melts, fails in tension or otherwise triggers, this actuates switch 47 , causing the circuit between terminals T- 1 and T- 2 to be broken and the circuit between T- 2 and T- 3 to be completed. As can also be seen, terminal T- 3 is connected to a bypass circuit beginning at the end of cell # 1 , such that with the bypass switch activated, a closed circuit exists between cell # 1 and cell # 3 , bypassing cell # 2 and allowing the battery to continue functioning despite the loss of that cell. In a typical application, a good battery cell may have an internal impedance of a few milli-ohms or less, a defective cell may have an impedance of hundreds of ohms or higher, and fusible link 46 in series with diodes 44 , 45 may have a resistance of about one ohm.
Cell # 3 is shown with a similar bypass circuit 43 . In a preferred embodiment, every cell in the battery will be protected by a bypass switch of the type described. Although the switch shown is a single-pole double-throw switch, other possible combinations may be used depending on the specific application. FIGS. 2 a and 2 b show one possible embodiment of the invention. Alternately, transistors rather than diodes can be used to activate a bypass circuit as soon as a predetermined power level is detected. The circuit may also be activated by sensors that sense gaseous pressure or temperature within a given cell.
The embodiments of the invention described herein are illustrative and not restrictive. Numerous variations may occur to those of skill in the art that fall within the spirit of the invention. The scope of the invention is therefore limited not by the particular examples described herein, but only by the scope of the attached claims. | A frangible actuator and switch isolates a defective cell in a battery by switching an electrical circuit when the current through a fusible link exceeds a predetermined value. The high impedance of the defective cell causes most of the battery's current to flow through the fusible link. The actuator releases a spring-loaded plunger when the high current causes tensile failure of a fusible link. Electrical contacts coupled to the pre-loaded plunger are displaced by a predetermined distance, causing the contacts to move into or out of contact with electrical terminals. The actuator includes two mating parts held together by a restrainig wire, which is in turn held in place by the fusible link. When the fuse melts, fails in tension or otherwise triggers due to excessive current, the restraining wire loosens and allows the two actuator parts to separate. This separation in turn permits the spring loaded plunger to advance, triggering the switching action. The actuator contains the fusible link on an insulator portion rather than on one of the mating parts, so that the connecting wires will not mechanically interfere with the separation of the mating parts. Pins are used between the mating parts to prevent unwanted rotation of the parts and to prevent the resulting false activation of that could thereby occur. The switching contacts use toroidal springs as contact elements to maximize contact area and thereby increase current capacity of the switch. | 7 |
CROSS-REFERENCE
This application is a 371 of PCT/JP95/02057 filed Oct. 6, 1995.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to γ-diketone compound derivatives having inhibitory activity against platelet aggregation and pharmaceutical compositions useful for the treatment and prevention of thrombotic diseases.
2. Background Art
Cardiovascular diseases are increased along with the change of dietary habits and the increase of advanced ages. Almost fifty percent of these diseases may be caused by thrombus.
Platelets in plasma are mainly associated with the formation of thrombus in organisms. For the purpose of the treatment and prevention of thrombotic diseases in clinical practice, there have been used a medicine which suppresses the functions of platelet or inhibits the aggregation of platelets, for example, aspirin which inhibits cyclooxygenase and ticlopidine which activates adenylcyclase.
In recent years, glycoproteins on platelet membrane have been progressively studied. As a result, it has been elucidated that the membrane glycoprotein called GPIIb/IIIa is a receptor of fibrinogen. This has therefore led to the expectation that a GPIIb/IIIa antagonist would become an inhibitor of platelet aggregation having a novel action mechanism effectively used for the treatment and prevention of the thrombotic diseases (Trends in Pharmacological Science, 13, 413, 1992).
The compounds as the GPIIb/IIIa antagonist include, for examples, monoclonal antibodies (Ann. N.Y. Acad. Sci., 614, 193, 1991), tripeptide derivatives comprising arginine-glycine-aspartic acid (J. Med. Chem., 35, 2040, 1992), amidinophenyl derivatives (J. Med. Chem., 35, 4393, 1992; Japanese Patent Laid-Open Publication Nos. 264068/1992, 334351/1992, EP-A-483667, EP-A-502536, EP-A-525629, EP-A-529858, EP-A-537980, WO-9307867 and WO-9402472), tyrosine derivatives (J. Med. Chem., 35, 4640, 1992), and piperidine derivatives (EP-A-512831, EP-A-540334 and EP-A-578535).
Further, for γ-diketone compounds, compounds having a peptide bond are known in the art (Japanese Patent Laid-Open Publication No. 235853/1990, WO09307867 and the like), whereas no compounds free from a peptide bond are known in the art. It is expected that such compounds not having any peptide bond are less likely to be metabolized by peptidases in vivo. Therefore, they are potentially promissing compounds which can offer prolonged duration of efficacy.
On the other hand, the development of a drug, not having side effects such as hemorrhage and with a highly selective function, as a therapeutic or preventive agent of thrombotic diseases has been desired in the art.
SUMMARY OF THE INVENTION
The present inventors have now found that a certain kind of a compound becomes a GPIIb/IIIa antagonist.
Thus, an object of the present invention is to provide novel compounds having inhibitory activity against the aggregation of platelets.
Another object of the present invention is to provide a pharmaceutical composition comprising a novel compound having the above effect.
Further object of the present invention is to provide a therapeutic or preventive method of thrombotic diseases which comprises administering a novel compound having the above activity.
Further object of the present invention is to provide the use of the novel compound having the above activity for preparing a pharmaceutical composition used for the therapy or prevention of thrombotic disorders. The γ-diketone compound according to the present invention is represented by the formula (I): ##STR3## wherein R 1 and R 2 which may be the same or different is hydrogen; lower alkyl in which at least one hydrogen atom may be substituted by hydroxyl, halogen, amino, carboxyl, lower alkoxy, lower alkylamino, or lower alkoxycarbonyl; phenyl in which at least one hydrogen atom of the phenyl may be substituted by hydroxyl, halogen, amino, carboxyl, lower alkoxy, lower alkylamino, lower alkoxycarbonyl, or halo-lower alkyl; or phenyl-lower alkyl in which at least one hydrogen atom of the phenyl may be substituted by hydroxyl, halogen, amino, carboxyl, lower alkoxy, lower alkylamino, lower alkoxycarbonyl, or halo-lower alkyl;
A is the following group (II) or (III): ##STR4## wherein R 3 is amidino or amino-substituted lower alkyl;
R 4 is hydrogen atom; lower alkyl in which at least one hydrogen atom may be substituted by hydroxyl, halogen, amino, or lower alkylamino; or amidino;
D, E, F, and G which may be the same or different is --CR 5 ═, --CR 5 R 6 --, --N═; --NR 5 --, --O--, --S--, --(CO)--, or a bond wherein R 5 and R 6 which may be the same or different is hydrogen or lower alkyl;
B is --Z--(CH 2 ) q COOR 7 wherein Z is --O-- or a bond, R 7 is hydrogen, lower alkyl, or an ester residue which can be removed under physiological conditions and q is an integer of 1 to 4; and
p is an integer of 1 to 3; and a pharmaceutically acceptable salt and solvate thereof.
The platelet aggregation inhibitor according to the present invention comprises as an effective ingredient a compound represented by the general formula (I) or a pharmaceutically acceptable salt and solvate thereof.
The compound according to the present invention has excellent inhibitory activity against platelet aggregation and, further, is free from side effects derived from hemorrhage and lack of selectivity for inhibitory action. Therefore, the present invention can provide a platelet aggregation inhibitor which is safe to the human body.
DETAILED DESCRIPTION OF THE INVENTION
Compound of the general formula (I)
The term "lower alkyl" as a group or a portion of a group used herein means a straight or branched alkyl chain having 1 to 6, preferably 1 to 4 carbon atoms. The term halogen atom means fluorine, chlorine, bromine or iodine. Furthermore, the term "haloalkyl" means an alkyl group in which one or more hydrogen atoms are substituted by halogen atoms.
In the general formula (I), R 1 and R 2 are a hydrogen atom, a lower alkyl group, a phenyl group or a phenyl-lower alkyl group. At least one hydrogen atom of this lower alkyl group may be substituted. Preferred examples of this substituent include a hydroxyl group, a halogen atom (preferably, chlorine, bromine or fluorine), an amino group, a carboxyl group, a lower alkoxy group (preferably, methoxy, ethoxy, n-propoxy or iso-propoxy), a lower alkylamino group (preferably, methylamino, ethylamino, propylamino, dimethylamino or diethylamino), or a lower alkoxycarbonyl group (preferably, methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl or iso-propoxycarbonyl). Furthermore, at least one hydrogen atom of the phenyl group may be substituted. Specific examples of this substituent include a hydroxyl group, a halogen atom (preferably, chlorine, bromine or fluorine), an amino group, a carboxyl group, a lower alkoxy group (preferably, methoxy, ethoxy, n-propoxy or iso-propoxy), a lower alkylamino group (preferably, methylamino, ethylamino, propylamino, dimethylamino or diethylamino), a lower alkoxycarbonyl group (preferably, methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl or iso-propoxycarbonyl), or a halo-lower alkyl group (preferably, trifluoromethyl or trifluoroethyl).
In addition, at least one hydrogen atom of the phenyl group in the phenyl-lower alkyl group (preferably, benzyl, 2-phenylethyl or 3-phenylpropyl) may be substituted. Preferred examples of this substituent include a hydroxyl group, a halogen atom (preferably, chlorine, bromine or fluorine), an amino group, a carboxyl group, a lower alkoxy group (preferably, methoxy, ethoxy, n-propoxy or isopropoxy), a lower alkylamino group (preferably, methylamino, ethylamino, propylamino, dimethylamino or diethylamino), a lower alkoxycarbonyl group (preferably, methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl or isopropoxycarbonyl), or a halo-lower alkyl group (preferably, trifluoromethyl or trifluoroethyl).
In the formula (II), the amino-substituted lower alkyl represented by R 3 is most preferably aminomethyl.
In the formula (III), R 4 is a hydrogen atom or a lower alkyl or amidino group. At least one hydrogen atom of the lower alkyl group may be substituted. Specific examples of the substituent include a hydroxyl group, a halogen atom (preferably, chlorine, bromine or fluorine), an amino group, or a lower alkylamino (preferably, methylamino, ethylamino, propylamino, dimethylamino or diethylamino).
The group represented by the formula (II) and the carbonyl group may be bonded to each other at any position without limitation, with the bonding at the 4-position to R 3 being preferred.
Examples of the group (III) include that D or G is --NR 5 --, --O-- or --S-- and the other represents a bond with both E and F representing --CR 5 ═. Specific preferred examples of the formula (III) include 4,5,6,7-tetrahydrothieno 3,2-c!pyridin-2-yl or 3-yl, 4,5,6,7-tetrahydrothieno 2,3-c!pyridin-2-yl or 3-yl, 1-methyl-4,5,6,7-tetrahydropyrrolo 3,2-c!pyridin-2-yl or 3-yl, 1-methyl-4,5,6,7-tetrahydropyrrolo 2,3-c!pyridin-2-yl or 3-yl, 4,5,6,7-tetrahydrofuro 3,2-c!pyridin-2-yl or 3-yl, and 4,5,6,7-tetrahydrofuro 2,3-c!pyridin-2-yl or 3-yl.
In the group --Z--(CH 2 ) q COOR 7 as B in the general formula (I), Z represents an oxygen atom or a bond with Z being preferably an oxygen atom. Further, q is preferably an integer of 1 or 2. Preferred examples of lower alkyls as R 7 include methyl, ethyl, n-propyl, iso-propyl, or n-, iso-, sec-, or t-butyl. R 7 may represent an ester residue which can be removed under physiological conditions. Specific examples of such ester residues include pivaloyloxymethyl, 1-(cyclohexyloxycarbonyloxy) ethyl, (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl.
The compound according to the present invention can be in the form of a salt. Such a salt includes a pharmacologically acceptable non-toxic salt. Preferred examples of the salt include inorganic salts such as a sodium salt, a potassium salt, a magnesium salt and a calcium salt, acid addition salts such as a trifluoroacetate salt, a hydrochloride salt, a sulfate salt, an oxalate salt, a methanesulfonate salt, and a citrate salt, and amino acid salts such as a glutamate salt and an aspartate salt.
The compound according to the present invention can be in the form of a solvate. The solvate preferably includes a hydrate and an ethanolate.
Preparation of the Compound represented by the Formula (I)
The compound according to the present invention can be prepared by the following processes.
Protective groups for an amino group which are generally used in peptide synthesis may be used in the following processes. Preferred examples of the protective group include t-butoxycarbonyl, benzyloxycarbonyl, 4-methoxybenzyloxycarbonyl, 2,2,2-trichloroethoxycarbonyl, trifluoroacetyl, allyloxycarbonyl and trityl. Furthermore, protective groups for a carboxyl group which are generally used in peptide synthesis may be used in the following processes. Preferred examples of the protective group include methyl, ethyl, t-butyl, benzyl, 4-methoxybenzyl, 4-nitrobenzyl, allyl and benzhydryl.
Process (1)
A compound of the formula (I) wherein A represents the group (III) can be prepared by the following reaction. ##STR5##
A compound represented by the general formula (IV), wherein A is as defined above, provided that R 4 in A is as defined above and, in addition, may represent a protective group for the amino group, is reacted with a compound represented by the general formula (V), wherein R 1 , R 2 , B, and p are as defined above, provided that R 7 in B is as defined above and, in addition, may represent a protective group for the ester group, in an inert solvent in the presence of a catalyst (VI) and a base at 0° to 180° C., preferably at 10° to 100° C., for 0.5 to 24 hr, preferably for 1 to 10 hr, and, thereafter, optionally subjected to deprotection, thereby giving the compound represented by the formula (I).
The compound represented by the general formula (IV) may be prepared according to a process described in Japanese Patent Application No. 265273/1993, and the compound represented by the general formula (VI) may be prepared according to a process described in Synthesis, p. 379 (1975).
Process (2)
A compound of the formula (I) where A represents the group (II), wherein R 3 represents an amidino group, can be prepared using the compound of the formula (VII) as a starting material. ##STR6##
Specifically, a cyano compound represented by the general formula (VII), wherein R 1 , R 2 , p, and B are as defined above, provided that R 7 in B is as defined above and, in addition, may represent a protective group for the ester group, is reacted with hydrogen sulfide and triethylamine in pyridine to give a thioamide which is then methylated with methyl iodide in an inert solvent (preferably, acetone), further reacted with ammonium acetate or ammonium carbonate in an inert solvent (preferably, methanol) and optionally subjected to deprotection, thereby preparing a contemplated compound.
For a person having ordinary skill in the art, it would be apparent that, in the above production processes, the sequence of the reactions may be determined so that no side reaction occurs in a function group which does not participate in the reaction and that the functional group may be protected with a protective group suitable for preventing the progression of an unfavorable reaction.
Use of the compound/pharmaceutical composition
The compound according to the present invention inhibits the aggregation of platelets by inhibiting the binding of platelet membrane protein GPIIb/IIIa and fibrinogen. Thus, the compound according to the present invention and a pharmacologically acceptable salt thereof are effective in the treatment and prevention of thrombotic disorders caused by the aggregation of platelets, particularly cerebral infarction, myocardial infarction, angina pectoris or peripheral arterioocclusion.
A pharmaceutical composition comprising the compound according to the present invention or a pharmacologically acceptable salt thereof as an effective ingredient can be administered to human and non-human animal subjects through any one of routes such as oral or parenteral routes such as intravenous injection, intramuscular injection, subcutaneous administration, rectal administration or percutaneous administration.
Therefore, the pharmaceutical composition comprising as an effective ingredient the compound according to the present invention may be processed into suitable dosage forms depending on dosage routes, and can be specifically formed into preparations mainly including injections such as intravenous injection or intramuscular injection, oral preparations such as capsule, tablet, granule, powder, pill, grains or troche, rectal preparations, oily suppositories or aqueous suppositories.
These preparations can be prepared in the usual manners with conventional additives such as an excipient, a filler, a binder, a humidifier, a disintegrating agent, a surface active agent, a lubricant, a dispersant, a buffer, a preservative, a dissolution aid, an antiseptic agent, a flavoring agent, an analgesic agent or a stabilizer. The aforementioned acceptable and non-toxic additives include, for example, lactose, fructose, glucose, starch, gelatin, magnesium carbonate, synthetic magnesium silicate, talc, magnesium stearate, methyl cellulose or a salt thereof, gum arabic, polyethylene glycol, syrup, vaseline, glycerin, ethanol, propylene glycol, citric acid, sodium chloride, sodium sulfite and sodium phosphate.
The content of the compound according to the present invention in the pharmaceutical composition may vary depending on dosage forms. It, however, generally ranges from about 1 to 70% by weight, preferably from about 5 to 50% by weight of the total composition.
The dose is appropriately determined in consideration of the use, and the age, sex and severity of a patient. The dose is generally in the range from about 0.1 to 1,000 mg, preferably from 1 to 200 mg per day to an adult patient for the purpose of the treatment of thrombotic disorders. The dose may be administered in one or more portions per day.
EXAMPLES
Preparation 1
3,4-Bis(t-butoxycarbonylmethyloxy)benzaldehyde
3,4-Dihydroxybenzaldehyde (9.67 g) was dissolved in acetone (250 ml), and potassium carbonate (21.3 g) and t-butyl bromoacetate (24.6 ml) were added thereto. The resultant solution was stirred at room temperature, and, 2.5 hr after the initiation of stirring, t-butyl bromoacetate (2 ml) was further added to the reaction mixture, followed by stirring for 3.5 hr. Water was added to the reaction mixture, and acetone was then distilled off. The aqueous layer was extracted with ethyl acetate, the resultant organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off. The residue thus obtained was purified by column chromatography on silica gel (500 g, chloroform:methanol=100:1) to give 25.4 g of the title compound (yield 99%).
1 H-NMR (CDCl 3 ) δ: 1.48 (9H, s), 1.49 (9H, s), 4.67 (2H, s), 4.70 (2H, s), 6.90 (1H, d, J=8.2 Hz), 7.35 (1H, d, J=2.0 Hz), 7.46 (1H, dd, J=2.0, 8.2 Hz), 9.84 (1H, s) EIMS (m/z): 366 (M + )
Preparation 2
3,4-Bis(n-butoxycarbonylmethyloxy)benzaldehyde
3,4-Dihydroxybenzaldehyde (6.91 g), potassium carbonate (20.7 g), n-butyl chloroacetate (15.5 ml), and sodium iodide (2.25 g) were dissolved in dimethylformamide (100 ml), and the solution was treated in the same manner as in Preparation 1 to give 13.4 g of the title compound (yield 73%).
1 H-NMR (CDCl 3 ) δ: 0.91 (3H, t, J=7.5 Hz); 0.92 (3H, t, J=7.5 Hz), 1.29-1.42 (4H, m), 1.59-1.69 (4H, m), 4.21 (4H, t, J=6.7 Hz), 4.78 (2H, s), 4.81 (2H, s), 6.93 (1H, d, J=8.1 Hz), 7.38 (1H, d, J=1.7 Hz), 7.48 (1H, dd, J=1.7, 8.1 Hz), 9.84 (1H, s) EIMS (m/z): 366 (M + )
Preparation 3
1,2-Bis(t-butoxycarbonylmethyloxy)-4-(3-hydroxy-1-propenyl)benzene
The compound (5.13 g) prepared in Preparation 1 was dissolved in tetrahydrofuran (40 ml). The solution was cooled to -30° C., and vinyl magnesium bromide (about 1.0M THF solution, 18.2 ml) was added thereto. The mixture was stirred at -25° to -30° C., and, one hr after the initiation of stirring, vinyl magnesium bromide (9.8 ml) was added thereto, followed by stirring for 30 min. An aqueous ammonium chloride solution (0.35M, 120 ml) was added to the reaction mixture, and tetrahydrofuran was distilled off. The aqueous layer was extracted with ethyl acetate, and the organic layer was washed with water, a saturated aqueous solution of sodium hydrogencarbonate, and water in that order, and dried over magnesium sulfate. The solvent was then distilled off, and the residue was purified by column chromatography on silica gel (300 g, chloroform--chloroform:methanol=50:1) to give 3.70 g of the title compound (yield 70%).
1 H-NMR (CDCl 3 ) δ: 1.47 (18H, s), 1.88 (1H, br s), 4.59 (2H, s), 4.60 (2H, s), 5.12 (1H, d, J=5.6 Hz), 5.18 (1H, dt, J=1.5, 10.3 Hz), 5.32 (1H, dt, J=1.5, 17.2 Hz), 5.94-6.04 (1H, m), 6.82 (1H, d, J=8.2 Hz), 6.87 (1H, d, J=1.8 Hz), 6.92 (1H, dd, J=1.8, 8.2 Hz), EIMS (m/z): 366 (M + )
Preparation 4
1,2-Bis(n-butoxycarbonylmethyloxy)-4-(3-hydroxy-1-propenyl)benzene
The compound prepared in Preparation 2 was treated in the same manner as in Preparation 3 to give 3.18 g of the title compound (yield 40%).
1 H-NMR (CDCl 3 ) δ: 0.91 (3H, t, J=7.5 Hz), 0.92 (3H, t, J=7.5 Hz), 1.29-1.41 (4H, m), 1.58-1.67 (4H, m), 1.93 (1H, d, J=3.9 Hz), 4.18 (2H, t, J=6.7 Hz), 4.19 (2H, t, J=6.7 Hz), 4.71 (2H, s), 4.72 (2H, s), 5.10-5.15 (1H, m), 5.18 (1H, dt, J=1.4, 10.5 Hz), 5.32 (1H, dt, J=1.4, 17.2 Hz), 5.94-6.04 (1H, m), 6.86 (1H, d, J=8.1 Hz), 6.89-6.96 (2H, m) EIMS (m/z): 394 (M + )
Preparation 5
1,2-Bis(t-butoxycarbonylmethyloxy)-4-(3-oxo-1-propenyl)benzene
Pyridinium chlorochromate (3.03 g), Molecular Sieves 4A (5.50 g) were suspended in dichloromethane (45 ml), and a solution of the compound (3.70 g), prepared in Preparation 3, in dichloromethane (45 ml) was added thereto. The mixture was stirred at room temperature for 1.5 hr. The reaction mixture was filtered through Florisil, and the filtrate was concentrated. The residue thus obtained was purified by column chromatography on silica gel (80 g, hexane:ethyl acetate=10:1-5:1) to give 1.59 g of the title compound (yield 43%).
1 H-NMR (CDCl 3 ) δ: 1.48 (9H, s), 1.49 (9H, s), 4.67 (2H, s), 4.68 (2H, s), 5.88 (1H, dd, J=1.7, 10.5 Hz), 6.42 (1H, dd, J=1.7, 16.9 Hz), 6.84 (1H, d, J=8.6 Hz), 7.14 (1H, dd, J=10.5, 16.9 Hz), 7.50 (1H, d, J=1.9 Hz), 7.59 (1H, dd, J=1.9, 8.6 Hz) EIMS (m/z): 392 (M + )
Preparation 6
1,2-Bis(n-butoxycarbonylmethyloxy)-4-(3-oxo-1-propenyl)benzene
The compound (2.57 g) prepared in Preparation 4 was dissolved in dichloromethane (65 ml), manganese dioxide (5.66 g) was added thereto, and the mixture was stirred at room temperature for 24 hr. The reaction mixture was filtered through Celite, and the filtrate was concentrated. The residue thus obtained was subjected to the above procedure again, and then purified by column chromatography on silica gel (90 g, hexane:ethyl acetate=5:1) to give 1.82 g (yield 71%) of the title compound.
1 H-NMR (CDCl 3 ) δ: 0.91 (3H, t, J=7.5 Hz), 0.92 (3H, t, J=7.5 Hz), 1.29-1.41 (4H, m), 1.57-1.68 (4H, m), 4.20 (2H, t, J=6.7 Hz), 4.21 (2H, t, J=6.7 Hz), 4.78 (2H, s), 4.80 (2H, s), 5.88 (1H, dd, J=1.7, 10.5 Hz), 6.42 (1H, dd, J=1.7, 17.2 Hz), 6.87 (1H, d, J=8.6 Hz), 7.13 (1H, dd, J=10.5, 17.2 Hz), 7.54 (1H, d, J=1.9 Hz), 7.60 (1H, dd, J=1.9, 8.6 Hz) EIMS (m/z): 392 (M + )
Preparation 7
n-Butyl 4-formylphenoxyacetate
The title compound (28.4 g, yield 99%) was prepared in the same manner as in Preparation 2, except that 4-hydroxybenzaldehyde (12.2 g) was used instead of 3,4-dihydroxybenzaldehyde.
1 H-NMR (CDCl 3 ) δ: 0.92 (3H, t, J=7.6 Hz), 1.30-1.40 (2H, m), 1.56-1.68 (2H, m), 4.23 (2H, t, J=6.9 Hz), 4.72 (2H, s), 7.01 (2H, d, J=8.8 Hz), 7.85 (2H, d, J=8.8 Hz), 9.91 (1H, s) SIMS (m/z): 237 (M + +1)
Preparation 8
n-Butyl 4-(1-hydroxy-2-propenyl)phenoxyacetate
The compound (16.5 g) prepared in Preparation 7 was treated in the same manner as in Preparation 3 to give 8.82 g (yield 48%) of the title compound.
1 H-NMR (CDCl 3 ) δ: 0.92 (3H, t, J=7.4 Hz), 1.30-1.40 (2H, m), 1.58-1.68 (2H, m), 1.91 (1H, d, J=3.5 Hz), 4.21 (2H, t, J=6.7 Hz), 4.62 (2H, s), 5.14-5.19 (1H, m), 5.19 (1H, dt, J=1.3, 10.3 Hz), 5.33 (1H, dt, J=1.3, 17.2 Hz), 6.03 (1H, ddd, J=5.9, 10.3, 17.2 Hz), 6.89 (2H, d, J=8.7 Hz), 7.30 (2H, d, J=8.7 Hz) SIMS (m/z): 264 (M + +1)
Preparation 9
n-Butyl 4-(1-oxo-2-propenyl)phenoxyacetate
The compound (8.80 g) prepared in Preparation 8 was treated in the same manner as in Preparation 6 to give 5.76 g (yield 66%) of the title compound.
1 H-NMR (CDCl 3 ) δ: 0.92 (3H, t, J=7.4 Hz), 1.30-1.40 (2H, m), 1.59-1.68 (2H, m), 4.22 (2H, t, J=6.7 Hz), 4.70 (2H, s), 5.89 (1H, dd, J=1.8, 10.5 Hz), 6.43 (1H, dd, J=1.8, 16.9 Hz), 6.97 (1H, d, J=9.0 Hz), 7.16 (1H, dd, J=10.5, 16.9 Hz), 7.96 (1H, d, J=9.0 Hz) EIMS (m/z): 262 (M + )
EXAMPLE 1
4- 1,4-Dioxo-4-(4,5,6,7-tetrahydrothieno 3,2-c!pyridin-2-yl)butan-1-yl!-1,2-phenylene!dioxy!diacetic acid trifluoroacetate
(a) The compound (491 mg) prepared in Preparation 5 and 5-t-butoxycarbonyl-2-formyl-4,5,6,7-tetrahydrothieno 3,2-c!pyridine (668 mg) were dissolved in 1,4-dioxane (12.5 ml), and 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride (101 mg) and triethylamine (105 μl) were further added thereto. The mixture was stirred at 80° to 90° C. for 21 hr. Chloroform was added to the reaction mixture, and the mixture was washed with 1N hydrochloric acid, water, a saturated aqueous solution of sodium hydrogencarbonate, and water in that order, and dried over magnesium sulfate. The solvent was then distilled off, and the residue was purified by column chromatography on silica gel (70 g, hexane:ethyl acetate=3:1) to give 464 mg of di-t-butyl 4- 1,4-dioxo-4-(5-t-butoxycarbonyl-4,5,6,7-tetrahydrothieno 3,2-c!pyridin-2-yl)butan-1-yl!-1,2-phenylene!dioxy!diacetate (yield 54%).
1 H-NMR (CDCl 3 ) δ: 1.47 (9H, s), 1.48 (9H, s), 2.89 (2H, s), 3.31 (2H, t, J=5.8 Hz), 3.36 (2H, t, J=5.8 Hz), 3.73 (2H, s), 4.52 (2H, s), 4.64 (2H, s), 4.68 (2H, s), 6.82 (1H, d, J=8.6 Hz), 7.50 (1H, d, J=2.0 Hz), 7.53 (1H, s), 7.66 (1H, dd, J=2.0, 8.6 Hz) FDMS (m/z): 660 (M + )
(b) Anisole (0.8 ml) and trifluoroacetic acid (3.2 ml) were added to the compound (288 mg) prepared in the above step (a), and the mixture was stirred at room temperature for 2.5 hr. Diisopropyl ether was added to the reaction mixture, and the resultant precipitate was collected by filtration to give 208 mg of the title compound (yield 85%).
1 H-NMR (DMSO-d6) δ: 3.11 (2H, t, J=6.1 Hz), 3.18-3.37 (4H, m), 3.46 (2H, t, J=6.1 Hz), 4.25 (2H, s), 4.76 (2H, s), 4.83 (2H, s), 7.00 (1H, d, J=8.8 Hz), 7.39 (1H, d, J=1.9 Hz), 7.67 (1H, dd, J=1.9, 8.8 Hz), 7.87 (1H, s), 9.16 (1H, br s), 13.02 (2H, br s) SIMS (m/z): 448 (M + +1)
EXAMPLE 2
Di-n-butyl 4- 1,4-dioxo-4-(4,5,6,7-tetrahydrothieno 3,2-c!pyridin-2-yl)butan-1-yl!-1,2-phenylene!dioxy!diacetate hydrochloride
(a) The procedure of Example 1 (a) was repeated, except that the compound prepared in Preparation 6 was used and, further, ethanol was used instead of 1,4-dioxane. Thus, 669 mg of di-n-butyl 4- 1,4-dioxo-4-(5-t-butoxycarbonyl-4,5,6,7-tetrahydrothieno 3,2-c!pyridin-2-yl)butan-1-yl!-1,2-phenylene!dioxy!diacetate was obtained (yield 68%).
1 H-NMR (CDCl 3 ) δ: 0.91 (3H, t, J=7.5 Hz), 0.92 (3H, t, J=7.5 Hz), 1.30-1.40 (4H, m), 1.50 (9H, s), 1.55-1.68 (4H, m), 2.89 (2H, s), 3.30 (2H, t, J=6.1 Hz), 3.36 (2H, t, J=6.1 Hz), 3.74 (2H, s), 4.20 (2H, t, J=6.6 Hz), 4.21 (2H, t, J=6.6 Hz), 4.52 (2H, s), 4.75 (2H, s), 4.79 (2H, s), 6.86 (1H, d, J=8.3 Hz), 7.53 (1H, s), 7.54 (1H, d, J=1.9 Hz), 7.67 (1H, dd, J=1.9, 8.3 Hz) FDMS (m/z): 659 (M + )
(b) Anisole (2 ml) and trifluoroacetic acid (8 ml) were added to the compound (669 mg) prepared in the step (a), and the mixture was stirred at room temperature for 2 hr. Chloroform (20 ml) and water (10 ml) were added to the reaction mixture, and the mixture was neutralized with sodium hydrogencarbonate and then separated into an organic layer and an aqueous layer. The aqueous layer was extracted with chloroform, and the extract was combined with the organic layer. The combined extract and organic layer were dried over magnesium sulfate, and the solvent was distilled off. The residue was purified by column chromatography on silica gel (40 g, chloroform:methanol=40:1) to give an oil. The oil was dissolved in dioxane (25 ml), and the solution was stirred for 15 min while blowing hydrochloric acid gas into the system. The resultant crystals were collected by filtration, washed with ether, and lyophilized to give 528 mg of the title compound (yield 87%).
1 H-NMR (CDCl 3 ) δ: 0.91 (3H, t, J=7.4 Hz), 0.92 (3H, t, J=7.4 Hz), 1.30-1.40 (4H, m), 1.58-1.68 (4H, m), 3.21-3.32 (4H, m), 3.36 (2H, t, J=6.3 Hz), 3.52 (2H, br t, J=10.5 Hz), 4.19 (2H, t, J=6.7 Hz), 4.20 (2H, t, J=6.7 Hz), 4.33 (2H, s), 4.75 (2H, s), 4.78 (2H, s), 6.85 (1H, d, J=8.6 Hz), 7.52 (1H, d, J=2.0 Hz), 7.57 (1H, s), 7.64 (1H, dd, J=2.0, 8.6 Hz), 10.28 (1H, br s) SIMS (m/z): 560 (M + +1)
EXAMPLE 3
4- 4-(4-Amidinophenyl)-1,4-dioxobutan-1-yl!-1,2-phenylene!dioxy!diacetic acid trifluoroacetate
(a) The procedure of Example 1 (a) was repeated, except that the compound prepared in Preparation 5 was used and 4-cyanobenzaldehyde was used instead of 5-t-butoxycarbonyl-2-formyl-4,5,6,7-tetrahydrothieno 3,2-c!pyridine. Thus, 285 mg of di-t-butyl 4- 4-(4-cyanophenyl) -1,4-dioxobutan-1-yl!-1,2-phenylene!dioxy!diacetate was obtained (yield 54%).
1 H-NMR (CDCl 3 ) δ: 1.48 (18H, s), 3.38-3.47 (4H, m), 4.65 (2H, s), 4.68 (2H, s), 6.85 (1H, d, J=8.5 Hz), 7.51 (1H, d, J=1.8 Hz), 7.67 (1H, dd, J=1.8, 8.5 Hz), 7.79 (2H, d, J=8.2 Hz), 8.12 (2H, d, J=8.2 Hz) FDMS (m/z): 523 (M + )
(b) Pyridine (7 ml) and triethylamine (1.3 ml) were added to the compound (399 mg) prepared in the step (a), and the mixture was stirred for 30 min while blowing hydrogen sulfide gas under ice cooling into the system and further stirred at room temperature for 2 hr. The solvent was distilled off, and the resultant crystals were purified by recrystallization from CHCl 3 to give 357 mg of di-t-butyl 4- 1,4-dioxo-4-(4-thiocarbamoylphenyl)butan-1-yl!-1,2-phenylene!dioxy!diacetate (yield 84%).
1 H-NMR (DMSO) δ: 1.42 (9H, s), 1.44 (9H, s), 3.33-3.42 (4H, m), 4.75 (2H, s), 4.81 (2H, s), 7.00 (1H, d, J=8.5 Hz), 7.42 (1H, d, J=1.8 Hz), 7.70 (1H, dd, J=1.8, 8.5 Hz), 7.96 (2H, d, J=8.5 Hz), 8.02 (2H, d, J=8.5 Hz), 9.68 (2H, br s) FDMS (m/z): 557 (M + )
(c) The compound (351 mg) prepared in the step (b) was dissolved in acetone (12 ml), methyl iodide (190 μl) was added thereto, the mixture was heated under reflux, and, 2.5 hr after the initiation of reflux, methyl iodide (95 μl) was further added thereof. Thereafter, the mixture was heated under reflux for 30 min, and the solvent was distilled off to give 553 mg of di-t-butyl 4- 1,4-dioxo-4- 4- (1-methylthio-1-imino)methyl!phenyl!butan-1-yl!-1,2-phenylene!dioxy!diacetate hydroiodide.
1 H-NMR (CDCl 3 ) δ: 1.48 (9H, s), 1.49 (9H, s), 2.64 (3H, s), 3.43 (4H, s), 4.65 (2H, s), 4.69 (2H, s), 6.86 (1H, d, J=8.8 Hz), 7.51 (1H, d, J=1.9 Hz), 7.69 (1H, dd, J=1.9, 8.8 Hz), 8.05 (2H, d, J=8.4 Hz), 8.14 (2H, d, J=8.4 Hz) SIMS (m/z): 572 (M + +1)
(d) The compound (547 mg) prepared in the step (c) was dissolved in methanol (12 ml), ammonium acetate (94.6 mg) was added thereto, and the mixture was heated under reflux for 3 hr. The solvent was distilled off, methylene chloride was added to the residue, insolubles were removed by filtration, and the filtrate was concentrated. Acetone and ether were added to the residue thus obtained, and the resultant crystals were collected by filtration to give 161 mg of di-t-butyl 4- 4-(4-amidinophenyl)-1,4-dioxobutan-1-yl!-1,2-phenylene!dioxy!diacetate hydroiodide SIMS (m/z): 541 (M + +1).
(e) The compound (159 mg) prepared in the step (d) was treated in the same manner as in Example 1 (b) to give 112 mg of the title compound (yield from the compound prepared in the step (b): 34%).
1 H-NMR (DMSO) δ: 3.32-3.46 (4H, m), 4.71 (2H, s), 4.78 (2H, s), 6.99 (1H, d, J=8.8 Hz), 7.39 (1H, d, J=1.9 Hz), 7.69 (1H, dd, J=1.9, 8.8 Hz), 7.94 (2H, d, J=8.8 Hz), 8.18 (2H, d, J=8.8 Hz), 9.39 (2H, br s), 9.84 (2H, br s) FDMS (m/z): 429 (M + +1)
EXAMPLE 4
Di-n-butyl 4- 4-(4-amidinophenyl)-1,4-dioxobutan-1-yl!-1,2-phenylene!dioxy!diacetate trifluoroacetate
a) The procedure of Example 3 (a) was repeated, except that the compound (1.18 g) prepared in Reference Example 6 was used and ethanol was used instead of 1,4-dioxane. Thus, 1.22 g of di-n-butyl 4- 4-(4-cyanophenyl)-1,4-dioxobutan-1-yl!-1,2-phenylene!dioxy!diacetate was obtained (yield 78%).
1 H-NMR (CDCl 3 ) δ: 0.91 (3H, t, J=7.3 Hz), 0.92 (3H, t, J=7.3 Hz), 1.30-1.41 (4H, m), 1.59-1.68 (4H, m), 3.37-3.46 (4H, m), 4.20 (2H, t, J=6.9 Hz), 4.21 (2H, t, J=6.9 Hz), 4.76 (2H, s), 4.80 (2H, s), 6.88 (1H, d, J=8.4 Hz), 7.55 (1H, d, J=1.9 Hz), 7.69 (1H, dd, J=1.9, 8.4 Hz), 7.80 (2H, d, J=8.8 Hz), 8.12 (2H, d, J=8.8 Hz) EIMS (m/z): 523 (M + )
(b) The compound (1.22 g) prepared in the step (a) was treated in the same manner as in Example 3 (b) to give 0.940 g of di-n-butyl 4- 1,4-dioxy-4-(4-thiocarbamoylphenyl)butan-1-yl!-1,2-phenylene!dioxy!diacetate (yield 72%).
1 H-NMR (CDCl 3 ) δ: 0.91 (3H, t, J=7.3 Hz), 0.92 (3H, t, J=7.3 Hz), 1.30-1.41 (4H, m), 1.59-1.69 (4H, m), 3.40 (4H, s), 4.20 (2H, t, J=6.9 Hz), 4.22 (2H, t, J=6.9 Hz), 4.76 (2H, s), 4.80 (2H, s), 6.87 (1H, d, J=8.4 Hz), 7.54 (1H, d, J=1.9 Hz), 7.69 (1H, dd, J=1.9, 8.4 Hz), 7.93 (2H, d, J=8.0 Hz), 8.02 (2H, d, J=8.0 Hz) SIMS (m/z): 558 (M + +1)
(c) The compound (0.940 g) prepared in the step (b) was treated in the same manner as in Example 3 (c) to give 1.36 g of di-n-butyl 4- 1,4-dioxo-4- 4- (1-methylthio-1-imino)methyl!phenyl!butan-1-yl!-1,2-phenylene!dioxy!diacetate hydroiodide.
1 H-NMR (CDCl 3 ) δ: 0.91 (3H, t, J=7.3 Hz), 0.92 (3H, t, J=7.3 Hz), 1.29-1.42 (4H, m), 1.60-1.69 (4H, m), 2.64 (3H, s), 3.42 (4H, s), 4.20 (2H, t, J=6.9 Hz), 4.21 (2H, t, J=6.9 Hz), 4.76 (2H, s), 4.80 (2H, s), 6.88 (1H, d, J=8.4 Hz), 7.54 (1H, d, J=1.9 Hz), 7.69 (1H, dd, J=1.9, 8.4 Hz), 8.18 (4H, s) SIMS (m/z): 572 (M + +1)
(d) The compound (1.36 g) prepared in the step (c) was dissolved in methanol (17 ml), ammonium acetate (261 mg) was added thereto, and the mixture was heated under reflux for 1.5 hr. The solvent was distilled off, methylene chloride was added to the residue, insolubles were removed by filtration, and the filtrate was concentrated. The residue thus obtained was purified by column chromatography on silica gel (55 g, chloroform:methanol=15:1-methanol) to give 460 mg of di-n-butyl 4- 4-(4-amidinophenyl)-1,4-dioxobutan-1-yl!-1,2-phenylene!dioxy!diacetate hydroiodide (yield from the compound prepared in the step (b): 41%).
1 H-NMR (CDCl 3 ) δ: 0.86 (3H, t, J=7.6 Hz), 0.90 (3H, t, J=7.6 Hz), 1.22-1.39 (4H, m), 1.53-1.67 (4H, m), 3.24 (4H, br s), 4.15 (2H, t, J=6.5 Hz), 4.18 (2H, t, J=6.5 Hz), 4.72 (2H, s), 4.75 (2H, s), 6.82 (1H, d, J=8.8 Hz), 7.46 (1H, s), 7.57 (1H, d, J=8.8 Hz), 7.95 (4H, s), 8.73-9.30 (3H, m) SIMS (m/z):
(e) The compound (369 mg) prepared in the step (d) was dissolved in dimethylformamide (7 ml), triethylamine (200 μl), di-t-butyl dicarbonate (165 μl), and 4-dimethylaminopyridine (8.3 mg) were added thereto, and the mixture was stirred at room temperature for one hr. Ethyl acetate was added to the reaction mixture, and the mixture was washed with 1N hydrochloric acid, water, a saturated aqueous solution of sodium hydrogencarbonate, and water in that order, and dried over magnesium sulfate. The solvent was then distilled off, and the residue was purified by column chromatography on silica gel (20 g, hexane:ethyl acetate=3:1-3:2) to give 280 mg of di-n-butyl 4- 4- N-(t-butoxycarbonyl)!amidinophenyl!-1,4-dioxobutan-1-yl!-1,2-phenylene!dioxy!diacetate hydroiodide (yield 64%).
1 H-NMR (CDCl 3 ) δ: 0.91 (3H, t, J=7.6 Hz), 0.92 (3H, t, J=7.6 Hz), 1.30-1.41 (4H, m), 1.56 (9H, s), 1.58-1.68 (4H, m), 3.37-3.47 (4H, m), 4.20 (2H, t, J=6.9 Hz), 4.21 (2H, t, J=6.9 Hz), 4.76 (2H, s), 4.80 (2H, s), 6.88 (1H, d, J=8.4 Hz), 7.55 (1H, d, J=1.9 Hz), 7.70 (1H, dd, J=1.9, 8.4 Hz), 7.96 (2H, d, J=8.4 Hz), 8.07 (2H, d, J=8.4 Hz) FDMS (m/z): 641 (M + +1)
(f) Anisole (1.5 ml) and trifluoroacetic acid (6 ml) were added to the compound (275 mg) prepared in the step (e), and the mixture was stirred at room temperature for 3 hr. Diisopropyl ether was added to the reaction mixture, and the resultant crystals were collected by filtration. The crystals were then purified by reversed phase chromatography (Cosmoseal 75C 18 -OPN=20 g, 0.2% aqueous trifluoroacetic acid solution:acetonitrile=7:3-1:1) and lyophilized to give 169 mg of the title compound (yield 60%).
1 H-NMR (CD 3 OD) δ: 0.91 (3H, t, J=7.6 Hz), 0.94 (3H, t, J=7.6 Hz), 1.31-1.43 (4H, m), 1.59-1.69 (4H, m), 3.46 (4H, m), 4.20 (2H, t, J=6.5 Hz), 4.21 (2H, t, J=6.5 Hz), 4.83 (2H, s), 4.89 (2H, s), 7.05 (1H, d, J=8.4 Hz), 7.60 (1H, d, J=1.9 Hz), 7.77 (1H, dd, J=1.9, 8.4 Hz), 7.93 (2H, d, J=8.8 Hz), 8.24 (2H, d, J=8.8 Hz) SIMS (m/z): 541 (M + +1)
EXAMPLE 5
n-Butyl 4- 4-(4-amidinophenyl)-1,4-dioxobutan-1-yl!phenoxyacetate hydroiodide
(a) The procedure of Example 4 (a) was repeated, except that the compound (4.18 g) prepared in Reference Example 9 was used and ethanol and dimethylformamide (4:1) are used as the solvent. Thus, 3.35 g of n-butyl 4- 4-(4-cyanophenyl)-1,4-dioxobutan-1-yl!phenoxyacetate (yield 54%).
1 H-NMR (CDCl 3 ) δ: 0.92 (3H, t, J=7.4 Hz), 1.31-1.42 (2H, m), 1.60-1.69 (2H, m), 3.38-3.48 (4H, m), 4.22 (2H, t, J=6.7 Hz), 4.70 (2H, s), 6.96 (2H, d, J=9.0 Hz), 7.79 (2H, d, J=8.7 Hz), 8.01 (2H, d, J=9.0 Hz), 8.12 (2H, d, J=8.7 Hz) EIMS (m/z): 393 (M + )
(b) The compound (3.23 g) prepared in the step (a) was treated in the same manner as in Example 3 (b) and recrystallized from ethyl acetate to give 2.07 g of n-butyl 4- 1,4-dioxo-4-(4-thiocarbamoylphenyl)butan-1-yl!phenoxyacetate (yield 59%).
1 H-NMR (CDCl 3 ) δ: 0.93 (3H, t, J=7.4 Hz), 1.31-1.41 (2H, m), 1.60-1.69 (2H, m), 3.43 (4H, s), 4.22 (2H, t, J=6.6 Hz), 4.70 (2H, s), 6.96 (2H, d, J=9.0 Hz), 7.94 (2H, d, J 9.0 Hz), 7.98-8.06 (4H, m)
(c) The compound (2.00 g) prepared in the step (b) was treated in the same manner as in Example 3 (c) to give 2.58 g of n-butyl 4- 1,4-dioxo-4- 4- (1-methylthio-1-imino)methyl!phenyl!butan-1-yl!phenoxyacetate hydroiodide.
1 H-NMR (CDCl 3 ) δ: 0.93 (3H, t, J=7.6 Hz), 1.30-1.42 (2H, m), 1.60-1.69 (2H, m), 3.17 (3H, s), 3.39-3.47 (4H, m), 3.75 (1H, br s), 4.22 (2H, t, J=6.9 Hz), 4.70 (2H, s), 6.96 (2H, d, J=9.0 Hz), 8.00 (2H, d, J=9.0 Hz), 8.19 (4H, s) SIMS (m/z): 442 (M + +1)
(d) The compound (2.45 g) prepared in the step (c) was treated in the same manner as in Example 4 (d) to give 2.21 g of the title compound (yield 88%).
1 H-NMR (DMSO-d6) δ: 0.87 (3H, t, J=7.4 Hz), 1.25-1.36 (2H, m), 1.52-1.62 (2H, m), 3.37-3.46 (4H, m), 4.13 (2H, t, J=6.6 Hz), 4.93 (2H, s), 7.06 (2H, d, J=9.0 Hz), 7.93 (2H, d, J=8.2 Hz), 7.99 (2H, d, J=9.0 Hz), 8.18 (2H, d, J=8.2 Hz) SIMS (m/z): 411 (M + +1)
EXAMPLE 6
4- 4-(4-Amidinophenyl)-1,4-dioxobutan-1-yl!phenoxyacetic acid hydrochloride
The compound (108 mg) prepared in Example 5 (d) was suspended in ethanol (2 ml), 1N sodium hydroxide (420 μl) was added thereto, and the mixture was stirred at room temperature for 2.5 hr. The solvent was distilled off, and water (14 ml), 1N hydrochloric acid (0.84 ml), and dimethylformamide (2 ml) were added thereto, and the mixture was stirred at room temperature for 30 min. The solvent was distilled off, and chloroform was added to the residue. The resultant crystals were collected by filtration to give 60 mg of the title compound (yield 73%).
1 H-NMR (CF 3 COOD) δ: 3.72 (4H, s), 4.96(2H, s), 7.14 (2H, d, J=8.8 Hz), 8.02 (2H, d, J=8.0 Hz), 8.15 (2H, d, J=8.8 Hz), 8.33 (2H, d, J=8.0 Hz) SIMS (m/z): 355 (M + +1)
Pharmacological test: Inhibitory activity against platelet aggregation
The inhibitory activity of the compound according to the present invention against platelet aggregation was examined with human PRP (platelet rich plasma).
Nine volumes of a blood sample was taken out of the vein of a normal male human with a syringe in which one volume of a 3.8% sodium citrate solution was charged. The blood sample was centrifuged at 170×g at room temperature for 10 min. The supernatant thus obtained was isolated as PRP. The residual blood sample that PRP had been taken out was centrifuged at 2,700×g for 15 minutes. The supernatant was then taken as platelet poor plasma (PPP).
A platelet aggregation test was conducted with an aggligometer (PAM-8C, manufactured by MEBANICKS Co., Ltd.). Compounds under test were dissolved in a 50% DMSO saline, a 50% methanol saline, or physiological saline. The compound under test and PRP were preincubated for 2 min. An aggregation inducer ADP (CHRONO-PAR REAGENTS 384 ADP, CHRONO-LOG Corp.) was used in the form of a dilution with saline so that the final concentration is 5 μM.
The anti-platelet aggregation activity was determined as an inhibition rate to platelet aggregation effect of ADP in the absence of a compound under test as follows. The results are tabulated in Table 1. ##EQU1##
TABLE 1______________________________________Example No. of Compound IC.sub.50 (μM)______________________________________1 0.132 2.03 0.0174 0.0235 0.0436 <0.1______________________________________ | A γ-diketone compound represented by the following formula (I) and a pharmaceutically acceptable salt and solvate thereof having platelet aggregation inhibitory activity is disclosed: ##STR1## wherein B is --Z--(CH 2 ) q COOR 7 and A is the following group (II) or (III): ##STR2## | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of our copending application, Ser. No. 738,876, filed on Nov. 4, 1976 and now abandoned.
FIELD OF THE INVENTION
This invention relates to an echo canceller for effectively preventing an echo disturbance in a long-delay telephone circuit.
BACKGROUND OF THE INVENTION
At the start of a telephone call in a long-delay telephone circuit using an echo canceller, since the connection of a telephone circuit has just been completed, the impulse response must be rapidly subjected to a large amount of correction from its initial value. If this correction is delayed, a large residual echo will occur at the start of the telephone call. On the other hand, after the impulse response has been formed to some extent, that is, after an appreciable period of time has elapsed from the start of the telephone call, it is desired that the correction of the impulse response is an operation slow enough to follow-up a circuit condition change and still provide an accurate follow-up response.
However, the conventional echo canceller cannot satisfy in principle the above contradictory requirements.
BRIEF SUMMARY OF THE INVENTION
An object of this invention is to provide an echo canceller, which eliminates a residual echo at the start of a telephone call and reduces influence from overlapping talkings.
To attain the above object of this invention, an echo canceller is adapted such that, to minimize a residual echo obtained by subtracting a pseudo-echo reproduced from an impulse response of an echo path from a true echo, the impulse response is corrected by using the product of the residual echo and a received input, characterized in that a variable coefficient circuit is provided between a circuit for obtaining the product and a circuit for correcting the impulse response, and that control means is provided for reducing the coefficient of the variable coefficient circuit in accordance with the lapse of time of the duration of the received input level exceeding a predetermined threshold level after receiving a circuit connection completion signal.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The principle, construction and operation of this invention will be clearly understood from the following detailed decription taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a block diagram illustrating an embodiment of this invention;
FIG. 2 is a circuit diagram illustrating an example of a circuit connection completion signal detector employed in the embodiment shown in FIG. 1; and
FIG. 3 is a block diagram illustrating an example of a variable coefficient circuit employed in the embodiment shown in FIG. 1.
DETAILED DESCRIPTION
With reference to FIG. 1, reference numeral 100 indicates a transmitting input terminal; 200 designates a transmitting output terminal; 300 identifies a receiving input terminal; 400 denotes a receiving output terminal; 500 represents a circuit connection completion signal terminal; 1 shows a subtractor; 2 refers to a received signal register; 3 indicates an impulse response register; 4 designates a convolution integrator; 5 identifies a multiplier; 6 denotes a variable coefficient circuit such as a variable attenuator; 7 represents a signal detector, such as a conventional speech detector, for detecting a received signal exceeding a predetermined threshold level under control of the detected output of a signal detector 9 mentioned below; 8 shows a timer for counting clock pulses, such as a counter; 9 refers to a circuit connection completion signal detector, such as a ground dc signal detector. A line from the terminal 100 to the terminal 200 forms a transmission path, while a line from the terminal 300 to a terminal 400 forms a reception path.
To make a feature of this invention clear, a conventional echo canceller which is obtained by eliminating circuits 6, 7, 8 and 9 from FIG. 1 and directly connecting the output of the multiplier 5 to the impulse response register 3, will first be described.
In such a conventional circuit construction, the received signal x arrives at a receiving input terminal 300 and is delivered out from a receiving output terminal 400 into a two-wire section including a telephone set. An echo (y) reflected in the two-wire section reaches a transmitting input terminal 100. Then, in the subtractor 1, a pseudo-echo (y) alone is subtracted from the echo (y) and the residual echo (e) is applied to a receiving side through a transmitting output terminal 200. If the pseudo-echo (y) is the same as the true echo (y), the residual echo (e) is zero and this implies that a complete echo cancellation has been achieved. On the other hand, the received signal x is applied to the received signal register 2 and is subjected to convolution integration in the convolution integrator 4 by an impulse response of the impulse response register 3. Accordingly, if the content of the impulse response register 3 is an accurate impulse response, the output from the convolution integrator 4 becomes the pseudo-echo (y) equal to the echo (y). In this case, the content of the impulse response register 3 starts from its initial value, for instance, the state in which all registers are in their reset states, and converges in such a direction that an adaptive control loop comprising the subtractor 1, the multiplier 5, the impulse response register 3 for storing an impulse response produced by the addition of the output from the multiplier 5, and the convolution integrator 4 operates to reduce the residual echo (e) to zero. During such a recurring operation, a correct impulse response is gradually produced in the impulse response register 3. In this case, in the multiplier 5, a multiplication of the following equation (1) is achieved using the content x of the received signal register 2 and the residual echo e, by which is calculated an amount of correction Δhj of the impulse response, which is added to the content of the impulse response register 3. ##EQU1##
Since the conventional system has such a construction and is designed to perform such an operation as described above, the algorithm of the adaptive control loop shown in the equation (1) is applied at the start of and during a telephone call.
Now, the features of the present invention will be clarified by a description limited only to the operation different from the conventional circuit. A first feature resides in the provision of the variable coefficient circuit 6 between the multiplier 5 and the impulse response register 3. A second feature lies in the provision of the signal detector 7 which is started by a circuit connection completion signal at the terminal 500 to detect a received signal exceeding a predetermined threshold level, and the timer 8 such as a counter for measuring the duration of the detected output.
The first feature is equal to changing the equation (1) to the following equation (2): ##EQU2## α: a variable coefficient
Namely, at the start of a telephone call, the variable coefficient is set so that α≧1.
Next, after a certain period of time has elapsed from the moment of the start of the telephone call, for example, after the sum total of the period of time for which the received power exceeded a predetermined threshold level (for instance, -31 dBnO) has reached about 500 ms, the variable coefficient is set so that α<1, and this is held till the end of the telephone call. In this case, for convenience of explanation, the above values of the variable coefficient will hereinafter be called as follows:
α≧1: the state A
α<1: the state B
For judging whether it is at the start of a telephone call or after a certain period of time has elapsed, a telephone circuit connection completion signal can be used. This signal is a ground dc signal produced at the time of completion of the connection of the telephone circuit in the No. 5 signal system recommended by CCITT (International Telegraph and Telephone Consultative Committee). Accordingly, the use of this signal enables the time of the start of a telephone call to be detected. Further, after the start of the telephone call, an impulse resonse is gradually formed, but since its manner of formation is substantially proportional to the length of a received input signal, the signal detector 7 is provided for detecting a received signal exceeding a certain threshold level and, after the start of the telephone call, the length of the received input signal exceeding the threshold level is measured by the timer 8 such as a counter or the like, and if the measured value has exceeded a certain value, for instance, 500 milli-seconds, the state A is altered to the state B.
An example of the circuit connection completion detector 9 is shown in FIG. 2, in which the ground signal applied from the terminal 300 to a terminal 9-1 is detected by the restoration of a relay 9-2 actuated by a direct current supplied through the terminal 300, so that a ground signal is applied to the terminal 500 through a relay contact 9-3 of the relay 9-2 and a terminal 9-4.
An example of the variable coefficient circuit 6 is shown in FIG. 3, in which the output of the multiplier 5 is applied, through a terminal 6-3, a multiplier 6-5 and a terminal 6-6, to the impulse response register 3. The variable coefficient α applied to the multiplier 6-5 is read out of the outputs of the read-only memory 6-4 under control of the outputs of the timer 8 and the circuit connection completion signal detector 9. For example, the read-only memory 6-4 stores two states α 1 and α 2 of the variable coefficient α, where the states α 1 and α 2 have a value greater than one and a value less than one, respectively. In the time interval of the above 500 milli-seconds indicated by the state of the output of the timer 8 at a terminal 6-1, the read-only memory 6-4 generates the variable coefficient α of the state α 1 (≧ 1). Accordingly, the output of the multiplier 5 is applied to the impulse response register 3 after multiplied by the variable coefficient α of the state α 1 . After the above 500 milli-seconds indicated by the state of the output of the timer 8 at the terminal 6-1, the read-only memory 6-4 generates the variable coefficient α of the state α 2 (< 1). In this time, the output of the multiplier 5 is applied to the impulse response register 3 after being multiplied by the variable coefficient α of the state α 2 . The state α 2 of the variable coefficient α from the read-only memory 6-4 is restored to the state α 1 in response to the output of the timer 8 which is generated after a predetermined time from the termination of the call detected by the signal detector 7 and applied from a terminal 6-7. In this manner, the states A and B are automatically shifted from one to the other, thereby to provide an optimum control in each case.
The number of states of the variable coefficient α can be further increased, so that the states of the variable coefficient α can be successively varied by the output of the timer 8 in course of time.
As has been described in the foregoing, the present invention employs a variable coefficient circuit and is adapted to change its coefficient in accordance with the states at the start of and during a telephone call, so that a rapid impulse response at the start of the telephone call can be set to thereby reduce a residual echo as much as possible, and during the telephone call, a slow and precise impulse response can be set. Accordingly, the circuit of this invention is little affected by external disturbance and is capable of sufficiently reducing a residual echo. | An echo canceller in a telephone circuit for minimizing a residual echo obtained by subtracting a pseudo-echo reproduced from an impulse response of an echo path from a true echo, in which the inpulse response is corrected by the use of the product of the residual echo and received input. A variable coefficient circuit is provided between a multiplier for obtaining the product and a circuit for correcting the impulse response. A control circuit is provided for reducing the coefficient of the variable coefficient circuit in accordance with the lapse of time of the duration of the received input exceeding a predetermined threshold level after receiving a circuit connection completion signal of the telephone circuit. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 60/834,736, filed on Aug. 1, 2006 under 35 U.S.C. §119(e), the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates a system and method of equipping specific types of nuclear power plants with low cost storage that has a very high thermal efficiency.
[0004] The invention also relates to systems and methods for operating nuclear reactors cost-effectively at maximum capacity so that nuclear plants will be able to compete with conventional fossil fueled power plants in their responsiveness to load changes over a wide range.
[0005] The invention also relates to a storage system and method for a high-temperature gas-cooled nuclear reactor wherein the storage system or the method has a high efficiency (over 90%) and a low cost, allowing the nuclear reactor to always operate at maximum reactor power, while remaining capable of varying its electrical output as does a steam power plant.
[0006] 2. Discussion of Background Information
[0007] Nuclear reactors have a large thermal inertia, which slows their responsiveness to variations in the demand for power from the grid. Their potential to become the major source of electricity is seriously affected by this limitation. Additionally, the initial cost of investment in a nuclear power plant is high; therefore, they must be built to operate at full capacity as it is too costly to operate them at low loads. Commercial nuclear reactors are kept operating full time to ensure a profitable return on the original investment, therefore, most nuclear reactors are designed for base load. Operating them at or below half-capacity is not economically attractive since halving the load nearly doubles the cost per KWh. Another limitation on their functionality is that due to their thermal inertia, nuclear reactors can have a slow transient response.
[0008] As currently designed, nuclear power plants are unable to follow the variable demands of the grid because they are expensive to operate at intermediate loads and unsuitable for rapid load following. Because they are used mostly for base power, the total contribution they can make to the grid is thereby limited. Sixty percent of the demand for electricity is for variable, controllable power. At present, this need is supplied by coal-fired steam and gas turbine power plants and to some extent by hydroelectric power. While coal-fired steam power plants can respond to load changes quickly and can operate well with a load of only 13% of design capacity, they are more expensive to use for generating electricity during periods of partial load as they must be designed for maximum capacity.
[0009] Various energy storage devices have been proposed to solve this problem, but all of these proposals have limited efficiency (about 75%) and are expensive. Furthermore, while storage systems have been proposed for solar thermal power plants (see Sargent & Lundy, “ Assessment of Parabolic Trough and Power Tower Solar Technology Cost and Performance Forecasts ”, SL-5641, (2002), the disclosure of which is hereby expressly incorporated by reference in its entirety), they are based on liquid heat transfer fluids and molten salts, which may be unsuitable for nuclear reactors.
[0010] Consider, for example, a high temperature nuclear reactor cooled by helium (He) or any intermediate heat transfer medium (see Baxi, C. B., et al.; “ Evolution of the Power Conversion Unit Design of the GT - MHR ”, presented at the International Congress on Advances in Nuclear Power Plants, (2006), the website http://en.wikipedia.org/wiki/Pebble_bed_reactor, and Penner, S. S.; Seiser, R. Schultz, K.; “Nuclear Energy for the Future”, Presented at the Meeting of the Doctors for Disaster Preparedness, Las Vegas Nev., 16-17 Jul. 2005, the disclosures of which are hereby expressly incorporated by reference in their entireties).
[0011] The invention solves one or more of the problems associated with conventional nuclear power plants, is simple in design, is more robust, is cheaper and lacks one or more of the disadvantages of conventional nuclear power plants.
SUMMARY OF THE INVENTION
[0012] The invention provides for a system and method for equipping specific types of nuclear power plants with low cost storage that has a very high thermal efficiency. As a result of the invention, nuclear reactors will be able to operate cost-effectively at maximum capacity and will be able to compete with conventional fossil fueled power plants in their responsiveness to load changes over a wide range.
[0013] The system and method can utilize a high temperature heat transfer medium, e.g., hot helium (He), and can be used to provide heat for a steam power plant. A steam power plant can, in particular, be used as it has a high turndown ratio and provides a fast response. Of course, any device that can use heat to generate electricity may be substituted. To increase its suitability for variable operation, the size of the steam power plant can be enlarged to several times that of the nuclear reactor without increasing the size of the nuclear reactor itself.
[0014] The invention also provides for a process for operating a nuclear reactor with a capability to store energy and deliver electricity when needed. The process comprises removing heat from a core of a nuclear reactor by a circulating liquid or gaseous heat transfer medium. The method also includes transferring the heat transfer medium at least one of directly to a power generating device capable of load following and to a storage system. Additionally, the process includes storing either the heat transfer medium or its heat in a storage system and delivering the either the stored heat transfer medium or its heat to the power-generating device when needed.
[0015] The heat transfer medium may be a compressed gas. The compressed gas may be helium. The heat storage system may comprise a set of tanks or a set of pipes containing or filled with high temperature resistant solids through which hot gas from the nuclear reactor is passed in one direction heating up the filling and leaving a section of the end cooled such that the gas exits the tank at a low temperature to be recycled to the reactor core leaving a small section cold, and the storage circuit is either switched to another cold tank or stopped. The hot tank may remain hot as a storage medium until the heat is needed, wherein when the heat is needed, a second stream of the same compressed gas is passed in a counter current way to be heated in order to be fed to the power generating device and in a closed circuit recycled to the storage and back to the power generating device until only a small section remains hot to insure constant temperature of the hot gas delivered to the power generating device.
[0016] The heat storage system may comprise a storage vessel configured such that heat is absorbed in a way that it spreads through the tank in a relatively sharp front, and preferably less wide than one tenth of the length of the vessel. The storage vessel may be similar to the design of a recuperative heat exchanger with the main difference being that in a recuperative heat exchanger the cycles are short and of similar duration and the counter current streams have similar velocities whereas when used for storage, whereby heating occurs whenever heat is available, and the heat recovery whenever needed to supply the variable load and the counter current streams may have totally different velocities. The power-generating device may be a steam power plant or a gas turbine. The heat transfer medium may be a liquid. The liquid may comprise one of a molten salt and a molten metal.
[0017] The gas may be compressed and the heat exchanged with a gas of the same composition but at lower pressure, which is used in separate circuits to deposit the heat in the storage tank and to recover it when needed to the power-generating device. The lower pressure may comprise about 3 atm to about 30 atm.
[0018] The process may further comprise storing hot liquid in one insulated tank, transferring it when not needed for power generation to a storage vessel, and when needed using it to provide heat to the power generating device preferably a steam power plant and the cooled liquid to a cold storage tank and when needed back to the reactor core.
[0019] The process may be capable of providing fast load following whenever needed by using sufficient storage and a steam power plant is configured for a high turndown ratio and fast response. The power-generating device may be capable of meeting a maximum variable load expected even when the load is larger than the rated capacity of the nuclear power plant, whereby the nuclear power plant is able to achieve a large capacity for short times using the stored heat.
[0020] The invention also provides for a system for storing heat in a nuclear power plant, wherein the system comprises at least one tank comprising solid media structured and arranged to store heat. The system is structured and arranged to pass a first fluid through at least one tank, transfer heat from the first fluid to the solid media, store the heat in the solid media, and transfer the heat from the solid media to a second fluid.
[0021] The first fluid may comprise a compressed gas. The compressed gas may comprise helium. The second fluid may comprise a compressed gas. At least one of the first and second fluids may comprise a compressed gas having a high pressure. The first fluid may comprise a compressed gas moving a predetermined velocity. The first fluid may be higher in temperature than the second fluid. The first fluid may pass through at least one device heated by nuclear fission before entering the at least one tank. The second fluid may be used to produce steam in a power plant before entering the at least one tank. The first fluid may comprise a compressed gas passing through at least one nuclear reactor core. The second fluid may comprise a compressed gas passing through a power plant generating electrical power.
[0022] The system may further comprise a control system controlling at least one of: when the first fluid is allowed to pass through the at least one tank and when the second fluid is allowed to pass through the at least one tank.
[0023] The system may further comprise a control system controlling at least one of: when the first fluid is allowed to pass through the at least one tank, when the first fluid is allowed to bypass the at least one tank, when the second fluid is allowed to pass through the at least one tank, and when the second fluid is allowed to bypass the at least one tank.
[0024] The solid media may comprise at least one of: alumina; silica; quartz; ceramic; pebbles made of at least one of alumina, silica, quartz, and ceramic; high conductivity and high temperature resistant particles; at least one packed bed of at least one of particles and pebbles; and at least one packed bed of solids. The system may be structured and arranged to move at least one of the first and second fluids through the at least one tank with at least one of uniform flow distribution and minimal pressure drops.
[0025] The system may further comprise at least one nuclear reactor core heating the first fluid before the first fluid enters the at least one tank and a steam power plant receiving the heated fluid from the at least one nuclear reactor core under certain conditions and receiving the second fluid from the at least one tank under certain other conditions.
[0026] The system may further comprise one or more valves controlling movement of the first and second fluids between the at least one nuclear reactor core, the at least one tank, and the steam power plant and one or more recycle compressors pressurizing the first and second fluids.
[0027] The first and the second fluid may comprise helium. The first and second fluids may comprise portions of the same compressed gas flowing in a closed system, wherein the portions have different temperatures when entering the at least one tank. The first fluid may comprise a fluid heated by at least one reactor core before entering the at least one tank and the second fluid comprises a fluid exiting a power plant before entering the at least one tank. The system may have the following three cycles; a first cycle wherein the first fluid bypasses the at least one tank, flows to a power plant, and returns to at least one reactor core, a second cycle wherein at least a portion of the first fluid flows through the at least one tank and returns to the at least one reactor core, and a third cycle wherein the second fluid passes through the at least one tank, flows to a power plant, and returns to the at least one tank.
[0028] The invention also provides for a system for producing electrical energy comprising at least one tank comprising solid media structured and arranged to store heat, at least one reactor core heating a first fluid before the first fluid enters the at least one tank, and a power plant receiving the heated fluid from the at least one reactor core under certain conditions and receiving a second fluid from the at least one tank under certain other conditions. The system is structured and arranged to pass the first fluid through the at least one tank, transfer heat from the first fluid to the solid media, store the heat in the solid media, and transfer the heat from the solid media to the second fluid.
[0029] The system may further comprise one or more valves controlling movement of the first and second fluids between the at least one reactor core, the at least one tank, and the power plant, one or more recycle compressors pressurizing the first and second fluids, and a control system controlling at least one of: when the first fluid is allowed to pass through the at least one tank, when the first fluid is allowed to bypass the at least one tank and pass through the power plant, when the second fluid is allowed to pass through the at least one tank, and when the second fluid is allowed to bypass the at least one tank and enter the at least one reactor core.
[0030] The system may have three cycles which include: a first cycle wherein the first fluid bypasses the at least one tank, flows to the power plant, and returns to the at least one reactor core, a second cycle wherein at least a portion of the first fluid flows through the at least one tank and returns to the at least one reactor core, and a third cycle wherein the second fluid passes through the at least one tank, flows to the power plant, and returns to the at least one tank.
[0031] The invention also provides for a method of storing heat comprising moving a portion of heated fluid from at least one reactor core to at least one tank comprising solid media structured and arranged to store heat and transferring the stored heat from the solid media to a fluid that can be used by a power plant to generate electrical energy.
[0032] The heated fluid and the fluid may comprise a compressed gas. The compressed gas may comprise helium. The method may further comprise pressurizing at least one of the heated fluid and the fluid to a high pressure.
[0033] The invention also provides for a process for providing a nuclear reactor with a capability to store energy and deliver electricity when needed, wherein the process comprises removing heat from a core of a nuclear reactor by a circulating liquid or gaseous heat transfer medium, transferring the hot heat transfer medium when needed directly to a power generating device capable of load following, and when needed to a storage system, and storing either the heat transfer fluid or its heat in a storage system capable of storing either the heat transfer medium or its heat and capable of delivering the either the heat transfer medium or its heat to the power-generating device when needed.
[0034] The heat transfer medium may be a compressed gas. The compressed gas may be helium. The heat storage system may comprise a set of tanks or a set of pipes containing or filled with high temperature resistant solids through which hot gas from the nuclear reactor is passed in one direction heating up the filling and leaving a section of the end cooled such that the gas exits the tank at a low temperature to be recycled to the reactor core leaving a small section cold, and the storage circuit is either switched to another cold tank or stopped. The hot tank may remain hot as a storage medium until the heat is needed, wherein when the heat is needed, a second stream of the same compressed gas is passed in a counter current way to be heated in order to be fed to the power generating device and in a closed circuit recycled to the storage and back to the power generating device until only a small section remains hot to insure constant temperature of the hot gas delivered to the power generating device.
[0035] The heat storage system may comprise a storage vessel configured such that heat is absorbed in a way that it spreads through the tank in a relatively sharp front, and preferably less wide than one tenth of the length of the vessel. The storage vessel may be similar to the design of a recuperative heat exchanger with the main difference being that in a recuperative heat exchanger the cycles are short and of similar duration and the counter current streams have similar velocities whereas when used for storage, whereby heating occurs whenever heat is available, and the heat recovery whenever needed to supply the variable load and the counter current streams may have totally different velocities. The gas may be compressed and the heat exchanged with a gas of the same composition but at lower pressure, which is used in separate circuits to deposit the heat in the storage tank and to recover it when needed to the power-generating device. The lower pressure may comprise about 3 atm to about 30 atm. The power-generating device may be a steam power plant, or a gas turbine or, a combination of both. At least one power-producing device may comprise a gas turbine is utilized. The heat transfer medium may be a liquid. The liquid may comprise one of a molten salt and a molten metal.
[0036] The process may further comprise storing hot metal in one insulated tank, transferring it when not needed for power generation to a storage vessel, and when needed using it to provide heat to the power generating device preferably a steam power plant and the cooled liquid to a cold storage tank and when needed back to the reactor core.
[0037] The process may be capable of providing fast load following whenever needed by using sufficient storage and a steam power plant configured for a high turndown ratio and fast response.
[0038] The power-generating device may be capable of meeting a maximum variable load expected even when the load is larger than the rated capacity of the nuclear power plant, whereby the nuclear power plant is able to achieve a large capacity for short times using the stored heat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
[0040] The FIGURE schematically shows one non-limiting embodiment of a high temperature nuclear reactor with storage capability.
DETAILED DESCRIPTION OF THE INVENTION
[0041] The FIGURE provides a schematic of one non-limiting embodiment of the invention. The system utilizes a nuclear reactor or reactor core RC, a distribution valve system DV, a first helium compressor HC 1 , a steam power plant SPP, a heat storage system HSS, a helium tank HT, a second helium compressor HC 2 , as well as one or more valves V, and conduits, e.g., pipes, for moving the helium through the system. The solid-line (cycle 1 ) indicates a flow of He between the reactor core RC, distribution valve DV, the steam power plant SPP, the valve V and the first compressor HC 1 , and then back to the reactor core RC. The dotted-line (cycle 2 ) indicates a flow of He between the reactor core RC, through the distribution valve DV, through the heat storage system HSS, valve V, and compressor HC 1 , and then back to the reactor core RC. The dashed-line (cycle 3 ) indicates a flow of He from the steam power plant SPP, to the helium tank HT, through the second compressor HC 2 , to the heat storage system HSS, and then to the steam power plant SPP.
[0042] As is apparent from the FIGURE, the invention provides for removing and storing the heat from hot He passing through one or more large storage tanks of the system HSS. The tanks can be filled with a suitable solid filling, which is resistant to (i.e., which can withstand) high temperature (e.g., pebbles or particles made from alumina, silica, quartz or ceramics) and preferably have a high heat capacity. Acceptable heat capacities (specific heat) are above 0.15 preferably above 0.2 and most preferably 0.25 and above. Heat conductivity should be above 2 W/m ° K. and preferably, above 5 W/m ° K. An example would be alumina balls (specific heat 0.27, conductivity 6-20 W/m ° K.). To minimize both the heating time of a particle and of the total pressure drop, their size should be preferably between 1 to 20 mm and most preferably between 3 to 10 mm to get acceptable heating times and pressure drop. While there may be other materials and other geometric shapes that may be preferable, the selection of appropriate materials and shapes are left to the artisan based upon the instant invention and cost considerations.
[0043] In accordance with the features of the invention, the following example is provided to further facilitate understanding of the invention. When the full capacity of the nuclear power plant is used to meet the demand for electricity, all the He from the reactor core RC can be fed directly to the steam power plant SPP. When the demand for electricity is reduced or, when the plant SPP is to operate from storage HSS, the excess He not required in the steam plant SPP is directed or diverted to the storage tanks of the system HSS where its heat is deposited or transferred into the solid filling. Then, the cool He exits the system HSS and is fed back to the nuclear reactor RC. The storage system HSS is designed to allow the deposited heat to progress as a narrow front along the length of the tank(s). The tank(s) should be sufficiently oversized so that the cool end remains relatively cool at the end of the storage cycle. The same would apply when the flow is reversed. The hot end of the tank(s) would still stay hot until the end of the heat recovery cycle. The capacity of the tank(s) should be sufficient to accommodate the maximum volume of storage needed.
[0044] When the stored heat of the system HSS is used to raise the temperature of the He (cycle 3 ), the flow through the system HSS is reversed and the cold He flowing into the system HSS from the second compressor HC 2 is fed to the cold end of the system HSS and exits the system HSS hot. Due to the excellent heat transfer between the gas and the solid heat storing media, there is practically no energy loss in the heat transfer. The only loss of energy is due to pressure drops through the solid media bed, and the heat loss through the walls of the system HSS. Both of these losses, however, can be minimized by taking these into account in designing the system. Here, the aim is to make energy storage of the system HSS as efficient as possible, and to do so more so than by any other available method.
[0045] When the power requirements of the system exceed normal capacity, all the He from the reactor core RC can be fed to the steam plant SPP. Additionally, pressurized He in the storage tank(s) of the system HSS is heated and also fed to the steam power plant SPP. This later flow represents a recycled counter flow through the storage tank(s) and then back to the steam plant SPP (cycle 3 ). The amount of gas in the He cycle 3 can be small, i.e., merely sufficient to compensate for the residence times in the reactor core RC, the power plant SPP, and the storage tank(s) of the system HSS.
[0046] The arrangement described above can be likened to a steam power plant which uses stored hot He as a fuel and which stores a supply for one day of operation (or for whatever period is desired). The steam plant can be designed to meet almost any desired delivery schedule as long as the total output per day does not exceed the total output of the nuclear reactor. Thus, for intermediate loads, one can operate the plant at double the capacity of the nuclear reactor, e.g., twelve hours each day, and store the total output during the night (directing just enough He to keep the steam power plant hot). In this case, the capacity of the steam power plant would have to be doubled.
[0047] The nuclear power plant could also be designed to supply instantaneously dispatchable electricity with a much larger electricity output than the capacity of the nuclear reactor itself for a limited period, i.e., based on demand. For example, by quadrupling the capacity of the steam power plant, one can supply instantaneously dispatchable electricity up to four times nominal capacity, as long as the total amount delivered does not reach the total capacity of the nuclear reactor for one day. To operate in variable mode, or to provide instantaneously available standby, however, the output of the steam power plant has to be kept above 13% of maximum capacity during this period. In this regard, the reactor can be shut down overnight and energy can be stored if enough heat is supplied to keep it warm.
[0048] The invention or aspects thereof can be applied to any other power generating device that can convert the energy of the hot heat transfer medium to electricity. It can be assumed, for example, that a grid will be powered by differently designed reactors; some for base power, (40% of total power requirement of the grid) and others for intermediate load activity or load following.
[0049] The invention or aspects thereof can also be applied to an HTR in which hot pressurized He (see Penner, S. S.; Seiser, R.; Schultz, K.; “Nuclear Energy for the Future”, Presented at the Meeting of the Doctors for Disaster Preparedness, Las Vegas Nev., 16-17 Jul. 2005, the disclosure of which is hereby expressly incorporated by reference in its entirety). Furthermore, the invention also contemplates using another pressurized gas which is expanded in a gas turbine to generate electricity and after cooling, is re-compressed and fed back to the reactor core. Such plants can be substituted for the steam power plant in the FIGURE. However, these other arrangements can limit the applicability of the invention to load following substantially. When used for intermediate loads, combined cycle gas turbine power plants are shut down at night and weekends and started up one hour before needed—so are the gas turbines.
[0050] As should be apparent from the FIGURE, the invention can be used with combined cycle power plants or with any closed loop gas turbine (see, for example, “Small Nuclear Power Reactors”, UIC Nuclear Issues Briefing Paper #60, June 2006, the disclosure of which is hereby expressly incorporated by reference in its entirety). These can be used for intermediate power by doubling the capacity of the gas turbine and bypassing it when not in use, storing the heat in the same way as described in the example which follows. In this case, however, fast load following over large amplitudes is no longer feasible because efficiency drops severely when operation is below 80% capacity.
[0051] The invention can be applied to any nuclear reactor in which the nuclear core is cooled by a circulating gas or liquid that can be used to heat or drive a power-generating device. A liquid heat transfer medium (of the type described in, for example, “Small Nuclear Power Reactors”, UIC Nuclear Issues Briefing Paper #60, June 2006) can also be used the same way in a tank filled with an appropriate temperature-resistant filling. Alternatively, one storage tank can be used for storing hot liquid and another for cold liquid. However, a much larger inventory of liquid is required when two empty tanks are used, therefore, the system described in the instant FIGURE is normally preferable.
Example
[0052] Consider a 250 MW high-temperature nuclear reactor in which the reactor core RC is cooled by circulating He under pressure. According to the invention, the hot He is used to raise or produce steam in a high-pressure, high-efficiency steam power plant SPP which has a fast response, a high turndown ratio and, can operate efficiently at 13% of capacity. Then, the gas is recycled cold to the reactor core RC. If the maximum capacity of the steam power plant SPP is increased four-fold to 1000 MW, 1000 MW can be delivered for short periods, even though the heat source is sufficient for only an average load of 250 MW. For load following, the output can be varied over the entire range, 150 to 1000 MW. For supplying intermediate power, the steam power plant SPP needs to be increased to 500 MW, operating 12-13 hours a day. In addition, it is assumed that 12 hours of storage might be optimal.
[0053] Assuming also that a steam power plant SPP requires 8000 BTU/KWh, 12 times that amount or 96,000 BTU per KW capacity is required to provide 12 hours of storage; for the total plant, a storage capability of 24,000 MMBTU is required. Given that the heat resistant solid filling of the system HSS will have a specific heat C p of 0.25 and that the temperature drop of the circulating He will be 1400° F., 0.125 tons of pebbles will be needed per KW installed or 31,200 tons of pebbles for the total plant, plus an excess of 15% to keep the two end sections at constant temperature, for a total of 36,000 tons. There are a significant number of suppliers for ceramic fillings in any desired shape, suitable alumina balls are made by MarkeTech (for example, grades P975 and P965). Special ceramic fillers can also be ordered.
[0054] Another option would be to use ready made, e.g., 4-foot diameter steel pipes, and have them prepared in a shop to provide 50 to 100 foot sections coated in the inside with an insulating heat resistant layer, and designed for easy on-site assembly. The pipes can be provided already filled with the proper filling material. This is especially advisable if more than one plant is built. In this example, 700 such pipes, each 100 feet long, would be needed (or, 1200 section, each 60 feet long).
[0055] In some high temperature nuclear reactors, the pressure of the helium can reach 70 to 100 atm. At this pressure, large tanks become expensive. A possible solution is to add a secondary circuit of helium at a lower pressure (2.0 to 50 atm, and preferably in the range of 20-35 atm) and heat exchange it with the primary circuit. The same applies to any other gaseous heat transfer medium used in the primary circuit. Later when needed, heat from the storage tank can be transferred to the power plant by the secondary circuit in the same manner as described above. This requires a vessel or tank volume of about 24,000 m 3 or 0.1 m 3 /KW.
[0056] It is preferable to use several tanks since a single tank of 24,000 m 3 is likely too large and not optimal. The number and dimensions of the tanks used in the system HSS will depend on local conditions. While vertical tanks placed in the ground are acceptable when conditions permit, horizontal tanks in which the two end sections are easily available for maintenance may be preferable. Both ends require a distributor and an outlet collection system. There are many proven designs for distribution and collection developed for catalytic reactors which are well-known to those skilled in the art. High L/D ratios are preferable as they promote an even flow distribution, and a good plug flow.
[0057] The example herein provides one possible embodiment. The desired volume of 20,000 m 3 can be achieved by installing 17 tanks placed horizontally, each 8 meters in diameter and 30 meters long. Each tank will provide 14,750 KW capacity. The heat flowing through one storage tank is 111 million BTU/hr, the temperature drop is 1400° F., and the molar Cp of He is 5.0 moles. Thus, the total flow of He is 20,570 moles/hr or, 5.7 moles/second. In Table 1 we have estimates for a proposed design for this example using a pressure of 30 atm and a tank with a length of 100 feet. It should be noted that the linear velocities are small and the pressure drop and the required re-compression energy for the storage bed is quite small, and for maximum delivery during load following this pressure drop and the compression requirements are acceptable and the storage efficiency is still very high.
[0058] Clearly, the total amount of electricity supplied per day cannot exceed 6 GWh/day, i.e., the capacity of the nuclear reactor in the instant example. With 12-hour storage, the maximum feasible output that can be supplied is 1 GW for 4 hours (of which 1 million KWh would come directly from the reactor RC and 3 million KWh from the storage HSS). An additional 2 GWh would have to be dispatched at the rate of 250 MW over a long time period.
[0059] The foregoing is an extreme case. In practice, load following up to 500 MW for the entire time desired could be provided by one gigawatt output for shorter periods. With experience, a practical dispatching schedule that allows the system to be used for intermediate loads, peak loads and instantaneously dispatchable energy can be devised, and the system can be designed accordingly. The proposed system maximizes flexibility by using multiple tanks and by allowing for an increase in storage capacity.
[0060] It should be apparent that there can be many potential variations in scheduling that fulfill the three constraints of the design: the capacity of the nuclear reactor, the storage supplied, and the size of the steam power plant. With the invention, the response to changes in demand can be as fast as with conventional steam power plants, and the nuclear reactors can always operate steadily at optimum conditions. Detailed cost estimates are not herein discussed, as they strongly depend on the location, timing and the desired load schedule. However, the following hypothetical example will illustrate the potential advantages of the invention.
[0061] Consider a 250 MW high-temperature reactor RC cooled with pressurized He and designed with 12 hour heat storage in the system HSS. For simplicity, all costs are based on 1 KW capacity. We assume that the cost of the nuclear reactor complex itself without storage is $2500/KW capacity of which $350 goes for the steam power plants. To operate in intermediate mode, the capacity of the steam power plant SPP must be doubled and this adds $350/KW to the cost. When designed for load following mode, the steam power plant capacity must be increased four-fold, raising the base cost by $1050/KW. The cost of heat storage of the system HSS would be the same in each case.
[0062] To store heat for 12 KWh, the storage system HSS need per KW capacity is 0.125 tons of solid media, which requires a storage vessel with a volume of 0.1 m 3 per KW at a cost of less than $200. If another $100/KW is added for the cost of the rest of the storage system HSS, the total cost of the heat storage is $300 per KW. This brings the total cost to $3,250 for the total power plant. To increase the capacity four-fold, another $700 should be added for the steam plant SPP. This brings the total cost to $3950/KW of the base plant or about 60% above the cost of the base-load only cost.
[0063] To supply 2 KW intermediate load from the same HTR without storage requires two 250 MW power plants. The incremental capital cost would be $2,500 compared to $750 for the storage case. Unlike the instant invention, which includes storage, however, this solution has very little load following capability. Where fast load following is required, however, the ability to produce up to 1 GW (as mentioned above) cannot be matched by any combination of HTRs without storage. Even if this were possible, the cost would be much higher.
[0064] The invention described herein places high-temperature nuclear reactors at a substantial economic advantage. Today, their market is limited because they are more expensive to build and operate than water-cooled reactors and, their maximum size is small. In addition to increasing the cost-effectiveness of nuclear reactors for base load, the invention also makes them economically attractive for supplying the variable demands of the grid, which is the major part of the total market for electricity.
[0065] It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to exemplary embodiments, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
[0000]
TABLE 1
Nuclear Plant Design
Parameter
Value
Nuclear Plant Size (MW)
250
Steam Power Plant Size (MW)
1000
Heat Transfer Fluid
He
Pressure (atm)
30
T Max (° F.)
1700
Daily kWh via Storage/kW Installed
12
Power Plant Efficiency (%)
42.6
(1 kWh = 8000 Btu)
[0000]
TABLE 2
Design of Storage
Parameter
Value
Storage: Number of Vessels
17
(Diameter × Length: m × m)
(8 × 30)
Solid Filling (mm)
10
Average Diameter Alumina Particles
Density (kg/m 3 )
4000
Bulk Density (kg/m 3 )
2400
Velocity in Storage Tank (m/sec)
0.12
Maximum Velocity in Storage Tank
0.48
During Load Following (m/sec)
Single Pass Pressure Drops in Storage
0.024
Tank (atm)
Maximum Single Pass Pressure Drops in
0.45
Storage Tank During Load Following (atm)
kWh Compression per kWh Generated
0.0006
Maximum kWh Compression per kWh Generated
0.011
During Load Following | A method of storing heat includes moving a portion of a heated fluid from at least one reactor core to at least one tank having solid media, storing heat from the portion of the heated fluid in the solid media, and transferring the stored heat from the solid media to a fluid that can be used by a power plant to generate electrical energy. A system for storing heat in a nuclear power plant includes at least one tank comprising solid media structured and arranged to store heat and an arrangement structured and arranged to pass a first fluid through the at least one tank, transfer heat from the first fluid to the solid media, store the heat in the solid media, and transfer the heat from the solid media to a second fluid. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way. | 6 |
RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of U.S. patent application Ser. No. 14/067,333 filed Oct. 30, 2013, and incorporates the foregoing by reference hereto.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates to a connector or fastener, and a system therefore, for use with a display material. In particular, the invention relates to a reusable fastener designed to secure material such as promotional posters, displays, and brackets to a peg board or slatwall display or other backing in a retail or similar environment. Of course, a person of ordinary skill in the art will understand that the invention is not necessarily so limited.
[0004] 2. Background of the Invention
[0005] In retail environments promotional and marketing display material are commonly affixed to open wall space near, or in anticipation of the arrival of, goods or services for sale. Conventionally, these materials, which can include posters, displays, product samples, or other materials, are affixed to a backing adapted for repeated display and removal of the items. A common type of backing is referred to as peg board, which consists of a durable material with a pattern of perforations located in a predetermined pattern. Connectors, fasteners, or brackets are designed to secure materials to the peg board in a secure or releasably secure manner. Also, due to the fact that these displays are frequently changed the connectors and fasteners must be reasonably capable of removal to allow for such updates. The prior art, however, fails to adequately accomplish these goals.
[0006] Prior art connectors, as shown in FIG. 1 , include devices that comprise a generally flat head connected to an extended body that is sized to be captured in the spaced apart holes of the peg board. The connectors pass through holes in the material to be displayed and then into the peg board and thereby provide a reasonably stable mounting mechanism.
[0007] Such connectors include so called “canoe clips.” These clips have a body that includes an elongated center gap and are sized slightly wider than the peg board holes, such that upon insertion the body is compressed about the gap to form sufficient tension to retain the clip. The head of the clip is flat without any indentations or grooves for removal or insertion. In fact, the clips do not include any particular structural elements to allow for removal. When the display is replaced the clips are pulled or pried out of place, normally in a destructive manner, thrown away and new clips are used for the next display. In this manner the clips are disposable and not suitable for reuse, and removal frequently results in damage to the underlying peg board which may also need replacement.
[0008] Another such device is the “Christmas tree” clip. These clips also contain a head and body, however, in this case the body includes a plurality of teeth disposed along the axis of the body, and each tooth is comprised of a circumferential flange angled to resist removal after insertion. Again, the clips do not include any convenient means of removal and are therefore designed for one-time disposable use, and when they are removed they also damage the peg board.
[0009] While these prior art clips are generally inexpensive plastic articles, ultimately the cost of continued replacement of used clips becomes very significant. The difficulty of inserting and removing the clips consumes a great deal of unnecessary labor, as well as frustration. Furthermore, the environmental impact of disposable clips is detrimental. Additionally, as noted, because these clips are not designed to be removed easily, over time they damage the peg board requiring further costs and expense. The combined cost of these inefficiencies is substantial, and can be in the millions of dollars or more every year for retailers and others that use peg board displays and the like.
[0010] Another use of such clips is to assemble displays, and in particular assembly of cardboard or corrugated display material. One such prior art device is known as the Viking clip, which is comprised of plastic and consists of a flathead screw with a nut or wing nut that affixes to the screw. The Viking clip, however, requires manipulation from both sides of the assembly since the nut must be placed on the screw after the screw is placed through the assembly. Frequently, given the size of the assemblies, this requires two people to perform the assembly. Viking clips are also sometimes used with peg board displays, but suffer from the drawbacks described herein.
[0011] The prior art clips suffer from another material drawback, they do not meet the full range of needs required for displays and in particular peg board displays. Displays frequently require more than just pinning a poster, backer, or header to the peg board. There is a need to affix brackets, dimensional signage, product samples, powered items, and the like. The prior art clips cannot meet these needs.
[0012] Another type of backing used in displays, and other applications, is slatwall (also known as slotwall) is a building material used in shopfitting for wall coverings or display fixtures. It consists of panels made with horizontal grooves that are configured to accept a variety of merchandising accessories. The panels are typically made from medium-density fiberboard (MDF), with a finish such as melamine paper pressed or laminated onto one or both sides. Grooves are then machined into the board and painted or fitted with plastic or aluminum inserts, which can then be used to attach or hang various items therefrom. Slatwall is used in retail environments, to machine shops, garages, basements, and the like.
[0013] Heretofore, it has not been possible to use any of the clip based systems with slatwall because clips do not have the ability to fit in the elongated horizontal groove of the slatwall.
[0014] Accordingly, a need exists for a fastener or clip, and system therefore, that overcomes the difficulties of the prior art.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1A shows a side view of a prior art canoe clip.
[0016] FIG. 1B shows a side view of a prior art Christmas tree clip.
[0017] FIG. 1C shows a side view of a prior art Viking clip.
[0018] FIG. 2A shows a perspective view of a hex head fastener.
[0019] FIG. 2B shows a side view of the fastener of FIG. 2A .
[0020] FIG. 2C shows a side view of the top of the fastener of FIG. 2A .
[0021] FIG. 3A shows a perspective view of a low profile fastener.
[0022] FIG. 3B shows a side view of the fastener of FIG. 3A .
[0023] FIG. 3C shows a sectional view taken along the line labeled 3 C of FIG. 3B .
[0024] FIG. 3D shows a top view of the fastener of FIG. 3A .
[0025] FIG. 3E show a partial side view of the fastener of FIG. 3A .
[0026] FIG. 4A shows a perspective view of a thumb screw fastener.
[0027] FIG. 4B shows a side view of the fastener of FIG. 4A .
[0028] FIG. 4C shows a side of the fastener of FIG. 4A rotated 90° from the position show in FIG. 4B .
[0029] FIG. 5A shows a perspective view of a security fastener.
[0030] FIG. 5B shows a side view of the fastener of FIG. 5A .
[0031] FIG. 5C shows a top view of the fastener of FIG. 5A .
[0032] FIG. 6A shows a perspective view of a nut.
[0033] FIG. 6B shows a top view of the nut of FIG. 6A .
[0034] FIG. 7 shows various views of a bracket, with a female connector.
[0035] FIG. 8 shows various views of a bracket, with a male connector.
[0036] FIG. 9 shows various views of a bracket.
[0037] FIG. 10 shows various views of an L-shaped bracket.
[0038] FIG. 11A shows a perspective view of a tool.
[0039] FIG. 11B shows a sectional view of the tool of FIG. 11A taken along the line labeled 11 B in FIG. 11A .
[0040] FIG. 12 shows various views of a tool.
[0041] FIG. 13 shows various views of a handle.
[0042] FIG. 14 shows a peg board display.
[0043] FIG. 15 shows a peg board display, fastener, and drill with tool bit.
[0044] FIGS. 16 a, b show a peg board display with backer paper.
[0045] FIG. 17 shows a peg board display and header.
[0046] FIG. 18 shows a peg board display and dimensional header.
[0047] FIG. 19 shows a slatwall fastener.
[0048] FIG. 20A shows a perspective view view of the slatwall fastener.
[0049] FIG. 20B shows a side view of the fastener of FIG. 20A .
[0050] FIG. 20C shows a top view of the fastener of FIG. 20A .
[0051] FIG. 20D shows a side view of the fastener of FIG. 20A rotated 90° from the position show in FIG. 20B .
[0052] FIG. 20E is a sectional view of the fastener of FIG. 20A taken along the line labeled 20 E in FIG. 20D .
[0053] FIG. 21 shows the slatwall fastener attached to a slatwall slat.
[0054] FIG. 22A shows perspective views of a fastener, wherein fasteners labeled I and II are have a ball head and fastener labeled III has a low profile head.
[0055] FIG. 22B shows side views of the fasteners of FIG. 22A , wherein fasteners labeled I and II are have a ball head and fastener labeled III has a low profile head.
[0056] FIG. 22C shows top views of the fasteners of FIG. 22A , wherein fasteners labeled I and II are have a ball head and fastener labeled III has a low profile head.
[0057] FIG. 23A shows a perspective view of an elongated fastener.
[0058] FIG. 23B shows a side view of the fastener of FIG. 23A .
[0059] FIG. 23C shows a partial side view of the fastener of FIG. 23A .
[0060] FIG. 24 shows the elongated fastener attached to a peg board display.
[0061] FIG. 25A shows a perspective view of a fastener nut.
[0062] FIG. 25B shows a top view of the fastener nut of FIG. 25A .
[0063] FIG. 25C shows a side view of the fastener nut of FIG. 25A .
[0064] FIG. 25D shows a sectional view of the fastener of FIG. 25A taken along the line labeled 25 D shown in FIG. 25C .
[0065] FIG. 26 shows a slatwall backer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0066] In the Figures, a system for affixing display materials to a surface is shown. In particular, FIGS. 2 show views of a fastener 10 adapted for use with a display surface, such as peg board, walls, and the like.
[0067] The fastener 10 includes a head 12 , which is hexagonal in shape. The hexagonal shape allows for the use of one or more tools (described below) to grip the head 12 and drive the fastener 10 into place and for removal of the fastener 10 . The head 12 is also threaded to allow for securement of various devices to the head 12 (detailed below). The head includes a notch 18 along the bottom of one side of the head 12 . The notch, as described below, provides a gripping mechanism to retain in place paper items such as posters, backers, headers, and the like, that are placed over the head 12 of the fastener.
[0068] The fastener 10 includes a stem 14 , which is inserted in the surface, such as a hole in peg board. The stem 14 is threaded, and more particularly, includes wide spaced threads that allow for insertion of the fastener 10 with a minimal number of turns. The fastener 10 is comprised of a semi-rigid material, such as plastic, such that it easily stays in place when inserted into a surface, but does not damage the surface when inserted and removed (especially in the case or peg board).
[0069] The fastener 10 includes a base 16 , which forms a circular skirt between the head 12 and the stem 14 . The base 16 has a diameter greater than that of the stem 14 and stem threads, and greater than the hole in which the fastener 10 is inserted. This provides for a snug fit substantially flush with the hole into which the fastener 10 is inserted. A tapered bevel 20 is included on the bottom of the base 14 , which is closer in diameter to the hole in which the fastener 10 will be inserted to allow for more easily centering the fastener 10 into the hole, as well as enhancing the snug fit when inserted.
[0070] The threads on the stem 14 are tapered/narrowed at the point where they contact the bevel 20 to allow for a flat even fit with the fastener 10 is inserted and threaded into the hole.
[0071] The fastener 10 is designed to be inserted and removed with a tool 100 , described in detail below.
[0072] FIGS. 3 show various views of an alternative fastener 10 , and in particular a low profile fastener 10 . The fastener 10 includes a head 12 , which has a substantially lower profile than the fastener 10 shown in FIG. 2 . The head 12 has a circular flange 22 , which performs the same function as the notch 18 of the fastener 10 show in FIG. 2 , namely to releasably capture paper items such as posters, backers, headers, and the like, that are placed over the head 12 of the fastener 10 shown in FIG. 3 .
[0073] The fastener 10 also includes a base 16 having two opposing notches 24 , which engage with the tool 100 for insertion and removal of the fastener 10 (described in detail below).
[0074] FIGS. 4 show various views of an alternative fastener 10 , and in particular a thumb screw fastener 10 . The fastener 10 comprises a head 12 , which has a thumbscrew shape allowing a user to insert and remove the fastener 10 with their thumb and finger. The fastener 10 includes a threaded stem 14 and a base 16 generally consistent in function with those shown for the fasteners 10 shown in FIGS. 2 and 3 .
[0075] The head 12 can also be removed and inserted with the tool 100 , described in detail below.
[0076] FIGS. 5 show various views of an alternative fastener 10 , and in particular a security fastener 10 . The fastener 10 has a threaded stem, but is without a defined protruding head. The fastener 10 has a base 16 , and notches 24 for engagement with the tool 14 for removal and insertion. The fastener 10 is difficult to remove by hand, or with conventional tools, allowing it to be used to hold in place items subject to theft. This feature is particularly useful for in-store displays of valuable products. The fastener 10 can be removed with the tool 100 .
[0077] FIGS. 6 show various views of a nut 26 that can be used with the fasteners 10 for further securement. The nut 26 includes wings 28 for grasping to thread the nut 26 on and off. The nut 26 has internal threads 30 that match the threads on the stem 14 of the fastener 10 . The nut 26 can be used to construct dimensional objects, such as boxes, cartons, and display figures, or to secure items to brackets that may be affixed to the display surface.
[0078] FIG. 7 shows a bracket 32 that can be attached to a display surface and that is compatible with the fasteners 10 . The bracket comprises a connector 34 , a female snap fit connector as shown in FIG. 7 , and a plurality of holes 36 . Each hole 36 has a built in threads that match the threads of the fasteners 10 .
[0079] FIG. 8 shows a bracket 32 with a male connector 34 designed to make an L-shaped connection with the bracket 32 shown in FIG. 7 . The brackets 32 (joined or separate) can be connected to the display surface with one or more fasteners 10 , and then articles can be affixed to the brackets 32 with the fasteners 10 and/or nuts 26 .
[0080] FIG. 9 shows a bracket 32 having a connector 34 and holes 36 (threaded) that is adapted for connection within slots 38 in a display surface. In the case of peg board displays, the bracket 32 can affix to the slots in the sides of the peg board.
[0081] FIG. 10 shows a bracket 32 that is a single piece L-shape. The L-shaped bracket 32 may have threaded holes 36 or not, and can otherwise be used the same as the previously described brackets 32 .
[0082] FIGS. 11 show various views of a tool 100 for insertion and removal of the fasteners 10 described above. The tool 100 has a shaft 102 that terminates in a hex head 104 to which a power drill (for example) can attach. The tool 100 has a base 106 for engaging the various heads 12 of the fasteners 10 . The base 106 includes an internal cavity shaped to mate with the head 12 of the thumb screw fastener 10 of FIGS. 4 . While the fastener 10 of FIG. 4 is designed for manual use, the tool 100 can also be used. The internal cavity includes rib cavity members 108 , which align and mate with the outer most ribs 15 of the head 12 of the fastener 10 of FIGS. 4 . The internal cavity includes hex shaped cavity portions 110 , on opposing sides of the internal cavity, which engage the hex head 12 of the fastener 10 shown in FIGS. 2 .
[0083] The tool 100 also includes feet 112 to engage the notches 24 in the base 16 of the fastener 10 shown in FIGS. 3 and 5 . In this manner, the tool 100 is compatible with all of the fasteners 10 of the present invention. The tool 100 further comprises opposing claws 116 that can grip the base 16 of the fastener 10 during insertion to make it easier to insert the fasteners 10 .
[0084] FIG. 12 shows a tool 100 that is a hand operated version of the tool 100 shown in FIG. 11 , otherwise the tool 100 is the same. FIG. 13 show a handle 114 that includes an internal hex shaped cavity 116 that can engage the hex head 104 of the tool 100 shown in FIG. 11 , or can directly engage the hex head 12 of the fastener 10 shown in FIGS. 2 .
[0085] In operation, the components described above can be used in combination with a display surface such as a peg board display 120 shown in FIG. 14 , which is commonly used in retail stores and in other establishments. The fasteners 10 are designed for insertion into the holes of the display 120 , as shown in FIG. 15 , with the tool 100 (either by hand or with a power tool as shown in FIG. 15 ). In one aspects of the invention, the fasteners 10 would be inserted into each corner, or around the perimeter of the display 120 , and act as anchors for later attachment of display materials.
[0086] FIG. 16 a shows display material 122 , such as a backer display, attached to the display 120 by inserting holes in the material 122 over the head 12 of the fastener 10 . Commonly backers are used to cover the display 120 . Backers are frequently removed, for example, to accommodate seasonally decorated displays (or for other reasons). The present invention, firmly secures the backer to the display 120 , but the backer can be easily removed without removing the fasteners 10 . In the prior art, to remove and replace the backer required removing the fasteners, which was difficult and time consuming. Removal required prying the fasteners out of the holes of the display, often resulting in destruction of the fasteners and damage to the holes of the display; or, if the fasteners were removed without destroying them the force needed to remove them sent them flying across the room which was hardly any better than destroying them. Once the old fasteners were removed, new fasteners had to be inserted, and on and on and on—each time a backer needed replacement. The present invention eliminates these problems, as backers can be removed and replaced without any change to the underlying fasteners.
[0087] Furthermore, multiple layers of display materials 122 can be applied over the heads 12 of the fasteners 10 . As shown in FIG. 17 , a header can be applied directly over the backer by merely pressing the holes in the header over the heads 12 of the fasteners 10 .
[0088] Headers are also frequently replaced, as they contain advertising and promotional material that typically used for a limited period of time. Again, in the prior art there is no way to secure or change the header, except to remove the fasteners in the exasperating fashion described above. The present invention suffers no similar limitations.
[0089] FIG. 18 shows the present invention used with dimensional display material 124 , such as a shaped or dimensional header. The header is affixed to the display 120 by placing the header over the head 12 of the fastener 10 (in this case the fastener shown in FIG. 2 ) and placing a nut 26 (threaded to match the threads of the head 12 ) over the exposed end of the fastener 10 . In a similar manner, the brackets 32 can be attached to the display 120 , and any other combination of materials. The present invention is enormously flexible in the way it can be used, without requiring removal of the fasteners; however, if removal is desirable this can be done easily and without damaging the underlying display 120 .
[0090] As described above, the fasteners can be used on other surfaces besides peg board. The fasteners can be applied directly to wood, stucco, or masonry walls by drilling a hole in the wall and then inserting the fasteners as described herein. The displays can be standard peg board of the type shown in the Figures or specialty displays that are designed with a minimal number of holes in specific patterns. These types of displays are sometimes used as in-store displays. The fasteners can be used to assemble dimensional items as well.
[0091] In another embodiment of the present invention, FIG. 19 shows a fastener 10 adapted for use with slatwall systems. Slatwall panels include elongated horizontal slots to which items can be attached. The slots are narrow at the end near the surface of the panel and wide at the bottom. A slot in a slatwall panel has a side profile that looks like an upside down letter T.
[0092] The fastener 10 includes a head 12 , which in this case is hexagonal in shape as described above and includes threads. The fastener 10 includes a stem 14 which depends downward from a base 16 . The stem 14 attaches to a retainer 19 . The retainer 19 is elongated along a longitudinal axis, and has a much narrow transverse profile. This allows the retainer 19 to be placed in a slot of a slatwall, when the longitudinal axis of the retainer 19 is parallel to the axis of the horizontal aligned slatwall slot. Upon insertion of the retainer in the slot, the fastener 10 is turned 90° in either direction and the longitudinal axis of the retainer 19 is then perpendicular to the horizontal slatwall slot, and retained therein. The retainer 19 is biased as shown so that the retainer 19 is arcuate, or curved. This allows the retainer 19 to act like a spring when in place such that the terminal ends of the retainer 19 grip the slot holding the fastener 10 in place.
[0093] The fastener 10 also includes a stop 17 located on the underside of the base 16 . The stop 17 if flattened on two sides, has opposing somewhat rounded edges and opposing somewhat squared off edges. The stop is shaped to allow the fastener 10 to initially easily turn from the insertion position to the retention position, but then stop turning when the fastener 10 has been rotated 90° thereby signaling that the fastener 10 is in place. The stop 17 engages with the upper narrow portion of the slot of the slatwall to accomplish this purpose.
[0094] The fastener 10 includes opposing notches 24 to allow the fastener 10 to be removed and inserted with the tool described herein above. The fastener 10 , although shown with a hex shaped head in FIG. 19 , and be configured with any of the various head described herein above or below. Thus, enabling the use of all the advantages and embodiments of the present invention described in reference to peg boards to be used with slatwall as well.
[0095] FIGS. 20 show various views of the fastener 10 shown in FIG. 19 . The head 12 of the fastener 10 is different, however, from the head 12 shown in FIG. 19 , but as described above the head 12 of the fastener 10 with the retainer 19 is fully interchangeable with any of the fasteners shown herein.
[0096] FIG. 21 shows the fastener 10 engaged in the slot of a slatwall display. The head 12 extends from the slatwall allow access and use as set forth herein.
[0097] FIGS. 22 shows various views of a fastener 10 with a head 12 that comprises a ball (and one having a low profile head). The ball can be of various sizes. The ball allows for users to place items over the ball and have them retained thereon, in a manner similar to the fastener shown in FIGS. 2 and 3 . This application would include, retaining backers and the like. The fastener 10 shown in FIG. 22 can be configured for slatwall by including the stem 14 and retainer 19 as shown in FIG. 19 .
[0098] FIGS. 23 shows various views of an extended fastener 10 , with a long necked head 12 . A shown in FIG. 24 , the fastener 10 can be used (for example) to attach a sign or other item to peg board or slatwall, especially when it is desired that the sign or other item extend some distance from the display surface. The fastener 10 show in FIGS. 23 and 24 can be configured for slatwall by including the stem 14 and retainer 19 as shown in FIG. 19 .
[0099] FIGS. 25 shows various view of a threaded nut 21 that can attach to the head 12 of a fastener 10 , and in particular the fastener 10 show in FIGS. 2 and 19 .
[0100] FIG. 26 shows a backer 23 adapted for use with slatwall displays. The backer 23 can be made from paper, or other suitable material, and can be retained in place by affixing to the head 12 of the clip 10 . As described herein, in the prior art backers are commonly used with displays, and are frequently replaced based on seasonal considerations or other periodic changes to the look of the displays. In the prior art, it was very difficult to remove and replace the backer because it required removal of the prior art clips. Backers were next to impossible to use with slatwall displays due to the lack of an adequate method of attachment. The present invention eliminates this drawback by allowing the backer to be affixed to the head 12 of one or more of the fasteners 12 shown herein, and in particular to the fastener 11 adapted for use with slatwall displays. The fasteners 10 can be attached to the perimeter of the display, and the backer 23 then pressed over the head 12 of the fastener 10 . The head 12 includes one or more devices as shown herein that retain the backer 23 , but still provide an undemanding way to remove the replacing the backer 23 . The backer 23 includes predefined perforations that align with the slots in the slatwall, and/or holes that can fit over the head 12 of the fastener 10 .
[0101] Unless otherwise defined, 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 methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety to the extent allowed by applicable law and regulations. In case of conflict, the present specification, including definitions, will control.
[0102] The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention. Those of ordinary skill in the art that have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention. | The invention relates to a reusable fastener designed to secure material such as promotional posters, displays, and brackets to slatwall or peg board or other backing in a retail environment. The fastener has a head designed to receive display material without removal, and includes brackets and other items as part thereof. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application No. 61/663,103, filed on Jun. 22, 2012, the disclosure of which is incorporated by reference herein in its entirety.
FIELD OF INVENTION
The present disclosure relates to a system and method for dynamically changing a channel in a wireless communication system. More particularly, the present disclosure relates to a wireless audience response system having at least one base unit and a plurality of handheld response units, and a method for dynamically changing a channel of the base unit.
BACKGROUND
Audience response systems are employed to retrieve (or receive) responses from a group of individuals at a central location. Such systems may be used in classroom settings, corporate meetings, or in other gatherings of individuals. Wireless audience response systems may include at least one base unit and a plurality of handheld units. Each handheld unit typically includes a keypad for inputting user responses.
In one known embodiment, all of the handheld units transmit signals on the same channel or band of frequencies. Such a system, however, may not be adaptable to accommodate a handheld unit transmitting on a different channel. In an alternative embodiment, an audience response system may include different hardware versions of handheld units that transmit on different frequencies. In such an embodiment, the base unit is configured to simultaneously receive signals on a plurality of frequencies. However, such a system may not be configured to maximize use of available bandwidth and therefore may not perform optimally.
SUMMARY OF THE INVENTION
A method of receiving signals in an audience response system on a plurality of channels comprises receiving a first number of signals on a first channel during a first period of reception for a first predetermined length of time. The method further comprises transmitting at least one acknowledgment signal. The method further comprises receiving a second number of signals on a second channel during a second period of reception for a second predetermined length of time. The method further comprises transmitting at least one additional acknowledgment signal. The method further comprises comparing the first number of signals to the second number of signals. The method further comprises adjusting a future predetermined length of time for a period of reception on one of the first and second channels based on the comparison.
An audience response system configured to be used during an audience response session comprises a plurality of transmission devices, including at least a first transmission device that transmits wireless signals on a first channel and a second transmission device that transmits wireless signals on a second channel different from the first channel. The audience response system further comprises a base unit. The base unit has a transceiver configured to receive wireless signals on a single channel. The base unit also has logic configured to place the transceiver in a first reception state to receive wireless signals on the first channel for a first length of time, and place the transceiver in a second reception state to receive wireless signals on the second channel for a second length of time. The logic is further configured to compare a number of wireless signals received when the transceiver is in the first reception state to a number of wireless signals received when the transceiver is in the second reception state. The logic is also configured to adjust a length of time for a period of reception on one of the first and second channels based on the comparison.
A base unit for an audience response system comprises a transceiver configured to receive wireless signals on a single channel. The base unit further comprises logic configured to place the transceiver in a first reception state to receive wireless signals on a first channel for a first length of time, and place the transceiver in a second reception state to receive wireless signals on a second channel for a second length of time. The logic is further configured to compare a number of wireless signals received when the transceiver is in the first reception state to a number of wireless signals received when the transceiver is in the second reception state. The logic is also configured to adjust a length of time for a period of reception on one of the first and second channels based on the comparison.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate various example systems, methods, and so on that illustrate various example embodiments of aspects of the invention. It will be appreciated that the illustrated element boundaries (e.g., boxes, groups of boxes, or other shapes in the figures) represent one example of the boundaries. One of ordinary skill in the art will appreciate that one element may be designed as multiple elements or that multiple elements may be designed as one element. An element shown as an internal component of another element may be implemented as an external component and vice versa. The drawings may not be to scale and the proportion of certain elements may be exaggerated for the purpose of illustration.
FIG. 1 is a simplified front plan view of one embodiment of a handheld unit for a wireless response system;
FIG. 2 is a simplified front plan view of one embodiment of a base unit for a wireless response system;
FIG. 3 is a simplified schematic drawing of components of one embodiment of a handheld unit in communication with a base unit;
FIG. 4 is a simplified schematic drawing of components of one embodiment of a base unit in communication with a plurality of handheld units;
FIG. 5 is a schematic drawing showing one example of stages of reception and transmission for a base unit on a first and second channel;
FIG. 6 is a schematic drawing showing an additional example of stages of reception and transmission for a base unit on a first and second channel;
FIG. 7 is a schematic drawing showing another additional example of stages of reception and transmission for a base unit on a first and second channel;
FIG. 8 is a schematic drawing showing yet another additional example of stages of reception and transmission for a base unit on a first and second channel; and
FIG. 9 is a schematic drawing showing one example of stages of reception and transmission for a base unit on a first, second, and third channel.
DETAILED DESCRIPTION
“Computer-readable medium,” as used herein, refers to any medium that participates directly or indirectly in providing signals, instructions and/or data to one or more processors for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media may include, for example, optical disks, magnetic disks or so-called “memory sticks.” Volatile media may include dynamic memory. Transmission media may include coaxial cables, copper wire, and fiber optic cables. Transmission media can also take the form of acoustic or light waves, such as those generated during radio-wave and infra-red data communications, or take the form of one or more groups of signals. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a CD-ROM, any other optical medium, punch cards, papertape, any other physical medium with patterns of holes, a RAM, a PROM, an EPROM, an EEPROM, a FLASH-EPROM, phase change memory, any other memory chip or cartridge, a carrier wave/pulse, or any other medium from which a computer, a processor or other electronic device can read.
“Logic,” as used herein, includes but is not limited to hardware, firmware, software and/or combinations of each to perform a function(s) or an action(s), and/or to cause a function or action from another component. For example, based on a desired application or need, logic may include a software controlled microprocessor, discrete logic such as an application specific integrated circuit (ASIC), a programmed logic device, memory device containing instructions, or the like. Logic may also be fully embodied as software.
“Signal,” as used herein, includes but is not limited to one or more electrical or optical signals, analog or digital signals, one or more computer or processor instructions, messages, a bit or bit stream, or other means that can be received, transmitted, and/or detected.
“Software,” as used herein, includes but is not limited to one or more computer readable and/or executable instructions that cause a computer or other electronic device to perform functions, actions, and/or behave in a desired manner. The instructions may be embodied in various forms such as routines, algorithms, modules or programs including separate applications or code from dynamically linked libraries. Software may also be implemented in various forms such as a stand-alone program, a function call, a servlet, an applet, instructions stored in a memory, part of an operating system or other type of executable instructions. It will be appreciated by one of ordinary skill in the art that the form of software is dependent on, for example, requirements of a desired application, the environment it runs on, and/or the desires of a designer/programmer or the like.
“User,” as used herein, includes but is not limited to one or more persons, software, computers or other devices, or combinations of these.
FIG. 1 illustrates a front plan view of one embodiment of a handheld unit 100 for a wireless response system. In the illustrated embodiment, the handheld unit 100 includes a plurality of buttons 110 configured to accept a user input. In alternative embodiments, the handheld unit may employ switches, dials, an LCD touch screen, a graphical user interface, or any other known interface configured to accept a user input.
FIG. 2 illustrates a front plan view of one embodiment of a base unit 200 for a wireless response system. In the illustrated embodiment, the base unit 200 includes a connector 210 configured to be connected to a port of a computer. In an alternative embodiment, the base unit may wirelessly communicate with a computer via an infrared or RF transmitter. In another alternative embodiment, the base unit does not directly connect to a computer.
The base unit 200 includes at least one LED 220 . The LED 220 may be configured to indicate on/off status and transmission status. In alternative embodiments, the base unit may employ a dial, an LCD screen, or other known indicators. In another alternative embodiment, the base unit does not include any indicators.
FIG. 3 illustrates one embodiment of a wireless response system 300 . In the illustrated embodiment, the system 300 includes at least one handheld unit 100 and at least one base unit 200 . The handheld unit 100 includes the plurality of buttons 110 described above that act as an input interface. Alternatively, the input interface may include a keypad, an LCD touchpad, dials, toggle switches, levers, knobs, buttons, or any other appropriate control or input mechanisms.
The handheld unit also includes an output interface 120 . In one embodiment, the output interface 120 indicates operating status to a user such as: a signal is being transmitted, an acknowledgment has been received, user entry has been confirmed, and a software update is being received. In such an embodiment, one or more LEDs, an LCD, or other display may serve as an output interface 120 . The handheld unit 100 further includes a power source 130 , such as the battery described above.
The handheld unit 100 further includes processing logic 140 and a wireless data transceiver 150 , such as a radio frequency (RF) transceiver configured to transmit RF signals as shown at 310 a and receive RF signals as shown at 310 b . In an alternative embodiment (not shown), the handheld unit may include an RF transmitter, but not a receiver or a transceiver. In another alternative embodiment (not shown), the handheld unit may include an infrared (IR) source configured to transmit data and/or an IR sensor configured to receive data.
The input interface 110 is in communication with processing logic 140 . When a user inputs a selection into the input interface 110 , the user selection is communicated to the processing logic 140 . The processing logic 140 then generates and formats a signal for transmission by the transceiver 150 . In one embodiment, the signal includes a stored address and the user selection. The address may be a number, a sequence of alphanumeric characters, a sequence of ASCII characters, and the like. In one embodiment, the address is permanently assigned to a handheld unit 100 .
The processing logic 140 is in signal communication with one or more computer-readable media, shown in FIG. 3 as a memory 160 . The memory 160 is used for data storage purposes, such as to store user responses and the address of the handheld unit 100 . The memory 160 also stores the software application and associated executable files, such as a bootstrap loader (“BSL”), RAM, and USB RAM, that are executed by the processing logic 140 to perform the audience response functions described above. Although the memory 160 is shown schematically as a single box, it should be understood that several computer-readable media may constitute the memory 160 .
FIG. 4 illustrates a simplified schematic drawing of one embodiment of a wireless response system 400 , having a base unit 200 in communication with a plurality of handheld units 100 A-N. The handheld units 100 A-N may be substantially the same as the handheld units 100 described above. It should be understood that the base unit 200 may be in data communication with a single handheld unit or many handheld units.
As shown in FIG. 4 , the base unit 200 includes an input/interface such as the connector 210 that is in signal communication with a computer 410 . In an alternative embodiment (not shown), the base unit may be a stand alone device that is not connected to an external computer.
The base unit 200 further includes an output/interface, such as the LED 220 . In alternative embodiments, the base unit may employ an LCD screen or other known displays and indicators.
The base unit 200 also has an RF transceiver 230 configured to receive an RF signal as shown at 420 a and send an RF signal as shown at 420 b . In an alternative embodiment (not shown), the base unit may include an RF receiver, but not a transmitter or a transceiver. In another alternative embodiment (not shown), the base unit may include an infrared (IR) sensor configured to receive data and/or an IR source configured to transmit data.
The transceiver 230 is in signal communication with processing logic 240 . In this embodiment, when a signal is received by the RF transceiver, it is communicated to the processing logic 240 , which decodes and parses the signal.
In one embodiment (not shown), the base unit may have an ID. The processing logic may be configured to only accept signals that contain the base unit ID, thus ensuring that any collected data is not skewed by spurious signals. In one embodiment, a replacement base unit may have the same ID as a first base unit. In such an embodiment, the replacement base unit would accept signals from the handheld units, without the need for reprogramming the handheld units. In another embodiment, all manufactured base units may have the same ID.
After the signal has been successfully decoded and parsed, the processing logic 240 may generate an acknowledgment signal that contains, for example, the address and an acknowledgment indicator. The acknowledgment signal may also include an indication of whether the user selection was accepted.
With continued reference to FIG. 4 , the base unit 200 also includes a computer-readable medium such as a memory 250 , configured, for example, as RAM, FLASH, EEPROM, or other types of writable memory. In one embodiment, the user selection and/or the address are stored in the memory 250 after the signal has been decoded and parsed by the processing logic 240 . The storing of the user selection and/or the address may occur before, after, or concurrently with the transmission of the acknowledgment signal. In an alternative embodiment (not shown), the base unit does not have a writable memory and the user selection and unique identifier are instead only communicated to an external computer.
In one embodiment, each of the handheld units 100 transmit signals on the same channel, or band of frequencies, and the base unit 200 is configured to receive the signals on that one channel. In one such embodiment, users are allowed to select one channel for the handheld unit 100 to broadcast from a plurality of channels, and the base unit 200 is set to receive signals on the one selected channel. In such an embodiment, all of the handheld units in the system must be set to the same channel.
In an alternative embodiment, the handheld units 100 transmit signals on a plurality of channels. In one such embodiment, one version of a handheld unit 100 is configured to transmit on a first channel, and a second version of a handheld unit 100 is configured to transmit on a second channel. In one known example, a first version of a handheld unit 100 is set to transmit signals on a first channel, and a second version of a handheld unit 100 is set to transmit signals on a first or second channel, depending on the size of the data packet being transmitted (e.g., small data packets may be transmitted on a first channel, and large data packets may be transmitted on a second channel). Although the above examples illustrate handheld units that transmit on two different channels, it should be understood that the handheld units 100 may also transmit on three or more channels.
In one known embodiment, where the plurality of handheld units 100 transmit signals on a plurality of channels, the base unit 200 is configured to simultaneously receive signals on a plurality of channels. For example, the base unit 200 may include two receivers, with a first receiver tuned to a first channel and a second receiver tuned to a second channel.
In another known embodiment, the base unit 200 is configured to receive signals on only one channel at a time, and therefore switches between a plurality of channels. FIG. 5 is a schematic drawing showing one such example 500 of stages of reception and transmission (or reception and transmission states) for a base unit on a first and second channel. In the example 500 , the base unit 200 receives signals on a first channel C A for a first period of reception for a first period of time t 1 . The base unit 200 then transmits acknowledgment signals on the first channel C A corresponding to each signal received during the first period of reception. Alternatively, the base unit may transmit the acknowledgment signal on another predetermined channel.
The base unit 200 then receives signals on a second channel C B for a second period of reception for a time equal to the first period of time t 1 . The base unit 200 then transmits acknowledgment signals on the second channel C B corresponding to each signal received during the second period of reception. Alternatively, the base unit may transmit the acknowledgment on another predetermined channel. In one such embodiment, all acknowledgment signals may be sent on the same channel, regardless of the channel the signals were received. In an alternative embodiment, the acknowledgment channel is determined by the channel on which the signal was received.
The base unit 200 then continues to alternate between the channels in the above-described manner.
In one known embodiment, each handheld unit 100 repeatedly transmits a response signal until an acknowledgment signal is received, or until the handheld unit 100 times out after a predetermined amount of time. The periods of base unit reception may be selected such that they are less than the time out period for the handheld units 100 . For example, in one known embodiment, the handheld units time out after transmitting a signal for 5 milliseconds, and the each period of base unit reception is 3 milliseconds. This allows the base unit to receive signals and transmit acknowledgments before the handheld units time out.
In one known embodiment, the handheld units 100 and the base unit 200 each transmit at the same transmission rate. In an alternative embodiment, different transmission rates may be employed. For example, the base unit may be configured to transmit at a variety of transmission rates. In one embodiment, the base unit may transmit acknowledgments on the first channel at a first transmission rate, and acknowledgments on the second channel at a second transmission rate different from the first.
Additionally, different handheld units may be configured to transmit at different pre-selected transmission rates. For example, a first handheld unit may transmit data on a first channel at a first transmission rate, and a second handheld unit may transmit data on a second channel at a second transmission rate.
Further, one or more handheld units may be configured to transmit signals at a plurality of different rates. For example, a handheld unit may be configured to transmit signals at a first or second transmission rate, depending on the size of the data packet being transmitted (e.g., small data packets may be transmitted at a higher rate, and large data packets may be transmitted at a lower rate, or vice versa). A handheld unit may transmit at a first transmission rate on a first channel, and at a second transmission rate on a second channel. As one of ordinary skill would understand, data is transmitted faster when it is transmitted at a higher rate, but is more susceptible to loss at greater distances.
FIG. 6 is a schematic drawing showing another example 600 of stages of reception and transmission for a base unit on a first and second channel. The example 600 begins like example 500 , with the base unit 200 receiving signals on a first channel C A for a first period of reception for a first period of time t 1 , then transmitting acknowledgment signals on the first channel C A or another predetermined channel. The base unit 200 then receives signals on a second channel C B for a second period of reception for a time equal to the first period of time t 1 , and transmits acknowledgment signals on the second channel C B or another predetermined channel.
Unlike example 500 , the base unit 200 then determines whether more signals were received on the first channel C A or the second channel C B . In the illustrated example 600 , the base unit determines that more signals were received on the first channel C A . Therefore, the base unit 200 receives signals on the first channel C A for a period of reception equal to the first period of time t 1 , transmits acknowledgment signals on the first channel C A or other predetermined channel, and then receives signals on the second channel C B for a period of reception that is for a second period of time t 2 that is less than the first period of time t 1 . The base unit 200 then transmits acknowledgment signals on the second channel C B or other predetermined channel.
As one of ordinary skill would understand, the number of handheld units in an audience response system may change over time. For example, new audience members may join an ongoing presentation, or existing members may leave the presentation. Additionally, some or all of the audience members may only provide responses to a select number of questions, rather than all of the questions. Therefore, the periods of reception for a base unit may be continuously adjusted during a session. In the illustrated example 600 , the base unit 200 always receives signals on the first channel for a period of reception equal to the first period of time t 1 , but adjusts the periods of reception on the second channel. After receiving signals on the second channel for the second period of time t 2 , the base unit determines that fewer signals were received, and employs a shorter third period of time t 3 . After further determination, the base unit employs a longer period of time t 4 , and then settles on an optimal period of time t 5 . In one embodiment, each period of reception is above a predetermined threshold to allow time for signals to be received.
It should be understood that example 600 is presented for illustrative purposes only. While an optimal period of time t 5 was found for the second channel C B in example 600 , the period of time may be continuously adjusted in other instances.
In one embodiment, the periods of time are adjusted based on the signals received on a channel during the most recent period of reception on that channel. In an alternative embodiment, the periods of time are adjusted based on the signals received on a channel during a group of periods of reception on that channel. In another alternative embodiment, the periods of time are adjusted based on all of the signals received on that channel during the audience response session.
FIG. 7 is a schematic drawing showing another additional example 700 of stages of reception and transmission for a base unit on a first and second channel. Example 700 is similar to example 600 , except in this example, the base unit 200 determines that more signals were received on the second channel C B than on the first channel C A . Therefore, the base unit 200 always receives signals on the second channel for a period of reception equal to the first period of time t 1 , but adjusts the periods of reception on the first channel.
FIG. 8 is a schematic drawing showing another additional example 800 of stages of reception and transmission for a base unit on a first and second channel. Example 800 is similar to examples 600 and 700 , except in this example, the base unit 200 adjusts the periods of reception on both the first channel and the second channel.
FIG. 9 is a schematic drawing showing another additional example 900 of stages of reception and transmission for a base unit on a first and second channel. Example 900 is similar to examples 600 , 700 , and 800 except in this example, the base unit 200 receives signals on three channels, C A , C B , and C C . In example 800 determines that more signals were received on the first channel C A than on the second channel C B or the third channel C C . Therefore, the base unit 200 always receives signals on the first channel for a period of reception equal to the first period of time t 1 , but adjusts the periods of reception on the second channel and third channel.
It should be understood that examples 600 - 900 are merely exemplary and are not intended to be limiting. In alternative embodiments, four or more channels may be employed. In other alternative embodiments, certain periods of reception may be lengthened while others are maintained or shortened. In still another alternative embodiment, channels may be dynamically added or subtracted as needed. Additionally, a base unit may include multiple transceivers, with one or more transceivers changing between multiple channels. It should be further understood that, although the examples 600 - 900 illustrate the various channels at what appear to be various amplitudes, this is for illustrative purposes only and is not meant to signify that the various channels operate at various signal strengths.
While example systems, methods, and so on, have been illustrated by describing examples, and while the examples have been described in considerable detail, it is not the intention to restrict or in any way limit the scope of the appended claims to such detail. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the systems, methods, and so on, described herein. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention is not limited to the specific details, and illustrative examples shown or described. Thus, this application is intended to embrace alterations, modifications, and variations that fall within the scope of the appended claims. Furthermore, the preceding description is not meant to limit the scope of the invention. Rather, the scope of the invention is to be determined by the appended claims and their equivalents.
To the extent that the term “includes” or “including” is employed in the detailed description or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed in the detailed description or claims (e.g., A or B) it is intended to mean “A or B or both”. When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. See, Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). | A method of receiving signals in an audience response system on a plurality of channels comprises receiving a first number of signals on a first channel during a first period of reception for a first predetermined length of time. The method further comprises transmitting at least one acknowledgment signal. The method further comprises receiving a second number of signals on a second channel during a second period of reception for a second predetermined length of time. The method further comprises transmitting at least one additional acknowledgment signal. The method further comprises comparing the first number of signals to the second number of signals. The method further comprises adjusting a future predetermined length of time for a period of reception on one of the first and second channels based on the comparison. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a merchandising wall structure which may be free-standing or anchored to a wall, and more particularly refers to a wall structure formed of individual panels which are attached to frame members of the wall structure, and have plastic reveals mounted intermediate the panels and the frame members.
2. Description of the Prior Art
Vertical merchandising walls are widely used in commercial establishments for the display of a wide variety of items. The display apparatus is universal and may be assembled to take a wide variety of shape and form configurations to accommodate a particular size and motif in a display area or showroom. The wall structures are generally formed of a plurality of panels which, in cooperation with frame members, are adapted to be readily assembled and disassembled, and which wall structures provide a functional and aesthetically appealing means for displaying a wide variety of articles. A wall of the type described is disclosed and claimed in U.S. Pat. No. 4,434,900. The edges of the individual panels are assembled to each other edge-wise by means of keyholes provided in the edge of one panel which engage screwheads provided in a post or another panel. Although this structure has been found adequate for many uses, it has the disadvantage that the panels or posts must be lifted in order for the screwheads to be engaged in the keyhole slots in an adjacent member.
In U.S. Pat. No. 4,625,477 a wall structure is disclosed which is comprised of a plurality of wall panels and metal standards or posts of tubular structure which are easily connected to each other by means of rotary latches retained in mortises provided in the edges of the panel members or related structures, and which latches are adapted to engage slots provided in the metal standard or post structures or other panel edges. The structures are engaged by sliding them together without the necessity for lifting any of them, inserting a key into an aperture of the latch mechanism, and rotating the key until an arcuate latch member of the latch mechanism engages slots in the standard affixed to an adjacent structure and latches the structures together. The latching structure has the advantage that it is recessed within the edges of the panels and therefore does not detract from the aesthetic appearance of the panels. Moreover, the latches may be readily engaged and disengaged by a simple rotation of a key inserted in the key aperture provided in the latch and in the panel. The standard disclosed is in the form of a square tube which is extruded from aluminum. Although this standard support structure has been found to be eminently suitable for the purpose, the cost of the aluminum extrusion is somewhat higher than would be desirable.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a new and improved vertical merchandising wall structure suitable for use in commercial establishments for various functions including the display of a wide variety of items, as well as for use as a wall structure generally.
It is a further object to provide a wall structure wherein a plurality of panels and posts may be relatively easily assembled and disassembled without the necessity for lifting the panel members and posts to engage and disengage the locking structures. This results in reduced installation time and costs and the involvement of fewer construction trades in the field.
It is still further an object of the invention to provide a wall structure of the type described having components which may be relatively inexpensively fabricated.
It is additionally an object to provide a wall structure having various improvements in both mechanical and esthetic features not exhibited in prior art structures.
These and other objects, advantages and functions of the invention will be apparent upon reference to the specification and attached drawings illustrating preferred embodiments of the invention, in which like parts are identified by like reference symbols in each of the views.
According to the invention, a merchandising wall structure is provided comprised of a plurality of wall panels and metal standards or posts, and for some applications pilasters, which are easily connected to each other by means of rotary latches retained in mortises provided in the edges of the panel members adapted to engage slots provided in metal standards or post structures or other structural edges. The metal standards or post structures are formed from sheets of cold rolled steel shaped in the form of a web, a pair of panel members extending one from each of the edges of the web and oriented substantially perpendicularly with respect to the web, and flanges extending one from each of the edges of the panel members and substantially perpendicular thereto, the flanges extending in opposite directions from each other. The structures are engaged by sliding them together without lifting, inserting a key in an aperture of the latch mechanism, and rotating the key until an arcuate latch member engages slots provided in the standard of an adjacent member and latches the two members together. The latching structure has the advantage that it is recessed within the edges of the panels and therefore does not detract from the aesthetic appearance of the panels. Moreover, the latches may be readily engaged and disengaged by a simple rotation of the key inserted in the key aperture provided in the latch and in the panel. Additional features of the invention include the provision of plastic reveals intermediate the standards and adjacent structures and dimpling and swagging structures provided in the walls of the standards.
BRIEF DESCRIPTION OF DRAWINGS
In the drawings:
FIG. 1 is a perspective view of a modular merchandising wall structure according to the invention, assembled from a plurality of wall panels, pilasters and standards.
FIG. 2 is an elevational view of a single wall panel.
FIG. 3 is a perspective fragmentary view of a vertical standard according to the invention.
FIG. 4 is a fragmentary front view of the standard shown in FIG. 3.
FIG. 5 is a left-edge view of the standard.
FIG. 6 is an end view of a standard as shown in FIGS. 3-5.
FIG. 7 is a perspective view of a plastic trim or reveal member.
FIG. 8 is an elevational view of the trim or reveal member of FIG. 7 showing the front portion.
FIG. 9 is a fragmentary elevational view of the left side of the plastic trim or reveal member of FIGS. 7 and 8.
FIG. 10 is an end view of the trim or reveal member of FIGS. 7-9.
FIG. 11 is a perspective view of a lock assembly according to the invention.
FIG. 12 is an elevational view of the locking mechanism shown in FIG. 11.
FIG. 13 is a cross-sectional view of a joint between two wall panels in disassembled form.
FIG. 14 is a cross-sectional view of the two wall panels of FIG. 13 in assembled condition.
FIG. 15 is an elevational view, partly broken away, of a joint between two wall panels with the bolt in unlocked position.
FIG. 16 is an elevational view, partly broken away, of the structure shown in FIG. 15 with the bolt in locked position.
FIG. 17 is a view of a standard partly in cross-section having a supporting bracket mounted thereon.
FIG. 18 is a cross-sectional view of a wall panel being mortised at both edges to receive a bolt lock.
FIG. 19 is a fragmentary cross-sectional view of a wall panel having a standard at both edges.
FIG. 20 is a cross-sectional view of a pilaster in the form of an obtuse angle having a standard at both edges.
FIG. 21 is a cross-sectional view of a pilaster in the form of a right angle having a mortise at one edge and a standard at the other edge.
FIG. 22 is a pilaster of U-shaped cross-section having a mortise at one edge and a standard at the other, and
FIG. 23 is a cross-sectional view of a pilaster having a T-shaped cross-section with a standard mounted at each edge.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a modular merchandising wall panel construction 10 is shown comprising a plurality of smooth wall panels 11, 12, 13 and 14, and display panels 15, 16 and 17 having horizontal grooves for mounting display brackets. The corners of the modular construction are formed by anular pilasters 18 and 19. Each joint is formed by a standard 20 co-operating with bolt locks mounted in mortised recesses at the edges of the complementary mating structure. The standards 20 are preferably formed of cold rolled steel.
Referring to FIGS. 3, 4, 5, and 6, a standard 20 is shown in the form of a channel structure 26 having a front wall 27, a left sidewall 28 and a right sidewall 29. An attachment flange 30 extends from the right sidewall 29, and a guide flange 31 extends from and is positioned perpendicular to the left sidewall 28, apertures 32 are provided in the attachment flange 30 for attaching the flange 30 to a wall panel. Pairs of slots 33 and 33a are provided in the left sidewall 28 for receiving lock bolts. Slots 35 are provided in the front wall 27 for receiving bracket inserts for supporting the majority of the load placed on the system in terms of merchandise and display hardware. Face dimples 36 are pressed into the front wall 27 intermediate the slots 35. The use of steel and the use of the cold rolling process to form the standard permits the standard to have incorporated therein the unique dimpling feature according to the invention. The dimples may be applied during the rolling process in any desired magnitude. This permits material of different thicknesses to be utilized to form the standard. When steel is used in forming the standards, because of its strength, thinner material may be utilized than would be required if the standards were formed of a weaker material such as aluminum. The presence of the dimples 36 in any desired elevation permits a thin steel sheet to be used in forming the standards while still enabling conventional brackets to be used without the necessity for redesigning the brackets to accommodate the thinner steel. Thus, brackets which are designed to be mounted on aluminum structure incorporating a thicker metal insert than the steel sheet of which the present standards are formed may be utilized and the presence of the dimples 36 compensate for the difference in thickness of the metal, thereby permitting conventional brackets to be utilized.
As an additional feature of the invention, areas intermediate the pairs of slots 33 and 33a are provided with protuberances 37 during the rolling process. This structure permits thin steel sheeting to be used while still providing sufficient strength to the areas between the slots 33 and 33a to be engaged by the arcuate bolt 56 without bending.
Referring to FIGS. 7-10, a reveal or trim member 44 is shown comprising a web 45, an attachment flange 46, and a face trim flange 47. A slot 48 is provided in the web 45 to permit a lock bolt to extend therethrough for engaging a standard 20. The reveal or trim member 44 may be formed of a plastic material such as polyvinyl chloride or other suitable plastic materials. A pair of reveals 44 are utilized with each standard 20, one reveal may be affixed to the attachment flange by means of screws extending through the attachment flange 46 of the reveal, and a second reveal may be attached to the guide flange 31 by means of staples passing through the attachment flange 46 of the reveal 44, the face trim flanges of both reveals extend over the front wall 27 of the standard 20. The reveals 44 provide several advantages. The reveal functions as a padding agent to assure that the joint between the panel/pilaster and steel standard is solid and does not rattle. The reveal also has an aesthetic function. It wraps the face of the steel standard, adding a radiused, softening element to the transition between the plain of the structural component face and the plain of the standard face. Additionally it visually reduces the width of the joint, making the vertical standard appear with less overall impact in the installation. The reveal can also be formed of materials having various integral colors, thereby providing a coloration concept for the system. All the component parts of the system, the panels, pilasters, steel standards, vinyl reveals, vinyl back caps and vinyl groove inserts are readily available in standard materials and may be promoted in matching colors. The ability to bring the various elements together in a homogeneity of elements in a complete system to achieve a completely monochromatically appearance provides another valuable feature of the system of the invention.
Referring to FIGS. 11 and 12, a bolt lock assembly 34 is shown. The bolt lock 34 is generally known in the trade a GIRO-bolt lock marketed by the Hafele American Company, High Point, N.C. As shown in FIGS. 11 and 12, this structure includes a housing 51 having a mounting plate 52 affixed thereto. A rotatable hub 53 is mounted in the housing and is provided with a hexagonal aperture 54. A radial arm 55, shown in FIG. 12, is connected to the hub 53 at one end and has an arcuate bolt 56 connected at the other end and extending through an aperture 57 provided in the mounting plate 52, and adapted, upon rotation of the hub 53, to enter a second aperture 58 also provided in the mounting plate 52. The assembly additionally includes an Allen crank wrench 59 having a hexagonal cross-section adapted to be inserted into the hexagonal aperture 54 of the hub 53.
Referring to FIGS. 13 and 14, a pair of wall panels 11 and 12 are shown. In FIG. 13 the panels are in disassembled state. The panel 11 has a bolt lock 34 recessed in a mortise 65 therein and a reveal 44 affixed thereto by staples 67. The panel 12 has a standard 20 affixed thereto by means of screws 63 extending through apertures 32,. A reveal 44 is mounted between the standard 20 and the panel 12.
FIG. 14 shows the structure of FIG. 13 after the panel 11 has been put in place in engagement with the guide flange 31 and left sidewall 28, and the bolt lock rotated until the arcuate bolt 56 is locked in place.
Referring to FIGS. 15 and 16, a pair of wall panels 11 and 12 are shown. The wall panel 12 has a metal standard affixed thereto. New wall panel 11 has a plurality of mortised recesses 65 provided therein in which are mounted rotary bolt locks 34 affixed to the wall panel 11 by means of screws 68. As shown in FIG. 15, the hub 53 has been rotated by inserting the crank-shaped Allen wrench 59 into the hexagonal aperture 54 and turning the crank until the arcuate bolt 56 has just entered the first slot 33 of the metal standard 20. FIGS. 16 shows the assembly after the crank has been further rotated and the arcuate bolt 56 penetrated and passed through the second slot 33a of the pair of slots of the metal standard 20. In this condition the two walls are firmly locked together and can not be pulled apart. The locked condition is also shown in FIG. 14.
Referring to FIG. 17, a standard 20 is shown having a bracket 71 mounted therein and useful for supporting shelves and other related items. The bracket has inserts 72 and 73 extending into slots 35 of the standard. The insert 72 has legs 74 and 75, the leg 75 defining a recess 78 engaging a portion of the front wall 27. The insert 73 has a leg 76 defining a recess 79 engaging a portion of the front wall 27. As a result the bracket is maintained in place. Conventionally the recesses 78 and 79 are designed to engage thick-walled extruded or stamped metal and are therefore quite wide. In order to permit the utilization of conventional brackets with wide recesses, dimples 36 are provided in the front wall 27 to take up the additional space and prevent excessive play of the structure.
Referring to FIG. 18, a wall panel 81 is shown having mortises 82 and 83 provided at its edges for receiving bolt locks. Reveals 84 are affixed to the edges by suitable means such as staples.
Referring to FIG. 19, a panel 85 is shown having standards 20 and reveals 84 affixed thereto by screws 63.
The modular merchandising wall panel construction of the present invention is extremely versatile. Joints may be formed between wall panels of many different styles such as decorative wall panels and display-type wall panels. In order to form a joint, it is only necessary that one structural member has a standard according to the invention affixed thereto by means of screws or other suitable fastening means, and the other structural member must have mortises provided in a plurality of positions in which rotary bolt locks are inserted and affixed. In order to connect two structural members together, they need only be made to slide together, and the crank inserted into the hexagonal apertures of the locks and rotated until the arcuate bolt 56 enters the first slot 33 of each standard, the crank being further rotated until the bolt end returns and enters and emerges from the second slot 33a of the standard. In this condition the two structures are locked together and cannot be pulled apart. For connecting structural members such as wall panels it is desirable to have at least one rotary bolt lock provided for each 3 feet of structural edge, and an equal number of pairs of slots provided in the standard of the other structural member for each rotary bolt lock used in the first structural member. In connecting two structural members such as two wall panels together, it is only necessary to slide the two panels together until their edges meet, and then rotate the hub of each rotary bolt lock until the arcuate bolt of each lock engages the slots of the metal standard. The two structures are then firmly locked together and cannot be pulled apart.
In order to assembly a plurality of wall panels, each panel may be provided with one metal standard at one edge and a plurality of rotary bolt locks at the other edge, as shown and described in FIGS. 13-16. Alternatively, as shown in FIG. 18, a wall panel 81 may be provided having mortises 82 and 83 in which rotary bolt locks 34 according to the invention may be provided at both edges. The panel may then be connected at both ends to structural members having standards.
FIG. 19 shows a wall panel 85 having standards 20 mounted one at each edge. Each edge may be then mounted to another structural member which has a plurality of rotary bolt locks 34 mounted therein.
The modular wall panel construction of the present invention may be affixed by means of suitable brackets to a permanent wall structure, or, alternatively, may be free-standing. In order for the structure to be free-standing in straight runs, a structural post which incorporates the elongate standard must be used. Otherwise, some of the wall panels must be oriented at an angle with respect to the others. In order to provide for this, the present invention includes structural members in the form of pilasters or posts. The pilasters may be provided with any desired angular shape, and may have either standards or rotary bolt locks at its edges.
In FIG. 20 is shown a pilaster 86 whose legs are at an obtuse angle with respect to each other. Affixed to the ends of the pilaster are a pair of standards 20 and reveals 44. Alternatively, a plurality of rotary bolt locks 34 may be substituted at one or both edges.
In FIG. 21 is shown a pilaster 88 in the form of a right angle. Here a plurality of mortises 89 and reveals 44 are provided at one edge adapted to receive a plurality of rotary bolt locks 34. A standard 20 and reveal 44 are affixed to the other edge. Wall panels may then be affixed to the edges of the pilaster by means of complementary locking means. Since the walls affixed to the pilaster 88 will be at right angles, the structure will be free-standing.
Referring to FIG. 22 a pilaster 91 is shown having a U-shaped cross-section. The structure comprises legs 92 and 93, one having a mortise 94 provided to receive a bolt lock 34 and the other being provided with a metal standard 20 and reveal 44 adapted to be attached to wall panels having bolt locks 34.
Referring to FIG. 23, a pilaster 96 is shown having a T-shaped cross-section comprised of legs 97, 98 and 99. Metal standards 20 and reveals 44 are provided at the end of each leg for being connected to wall panels having bolt locks.
The modular merchandising wall panel instruction of the present invention has a number of advantages over the structures of the prior art. First, in contrast to the case of fastening means such as keyholes and bolts, the panels of the present structure need not be lifted in order to engage their edges. It is only necessary to slide the panels together until their edges are in engagement. Then the Allen wrench crank is inserted in the hex apertures of the bolt locks and turned until the bolts engage the slots of the metal standard of the adjoining structural member. Once the bolts are engaged, the structural members cannot be pulled apart, but can only be released by rotating the bolts in the opposite direction. Many different types of panels may be affixed together. The structure may be made free-standing by utilizing a pilaster to connect the wall panels at an angle. Wall panels may be connected to wall panels and wall panels may be connected to pilasters. It is only necessary that the engaging edge of one structural member be provided with a metal standard having appropriately placed pairs of engagement slots, and the edge of the other structural member be provided with a plurality of bolt locks at positions where they may engage the slots of the metal standard. A simple rotation of the Allen wrench crank will then firmly lock the members together. The bolt locks are commercially made and may be readily obtained in the market. The metal standard may be readily formed by stamping or rolling a relatively inexpensive material such as sheet steel, and then machined to provide the proper engagement slots. Modular structures may then be assembled such as the one shown in FIG. 1. Infinite configurations and site requirements can thus be accommodated.
Secondly, structures of the prior art require elaborate and costly wall preparation for structural integration. Existing building walls must be furred, and numerous horizontal and vertical channels must be applied in order to create an intra-structure to which the decorative wall or display-type panels are then applied. No such preparation methods or costs are required of the invention described herein.
A further advantage of the invention results from the fact that the use of reveals of various colors enables systems according to the invention to be marketed and assembled in any of a number of monochromatic patterns. The reveals additionally function as padding agents to enable the joints between the structural elements to secure and quiet.
It is to be understood that the invention is not to be liminted to the exact details of construction or operation or materials shown and described, as obvious modifications and equilvalents will be apparent to those skilled in the art. | A modular merchandising wall panel construction including at least two vertically oriented structural members in edge-to-edge engagement, and means affixing the structural members together and permitting ready disassembly thereof, comprising a vertically oriented standard affixed to the edge of one structural member, the standard being in the form of a channel having flanges extending therefrom, a wall of the channel having slots provided therein, and a plurality of rotary bolt locks mounted in the edge of the other structural member, the rotary bolt lock having an arcuate bolt engaging the slots of the vertical standard, thereby locking the structural members together, and permitting easy disassembly thereof. In one embodiment of the invention some of the structural members comprise pilasters also having rotary bolt locks or vertical standards for assembly with the other structural members. In a further improved embodiment plastic reveals are inserted between the walls of the standard and the edges of the structural members to provide a more secure joint and also to improve the esthetic appearance of the modular structure. | 4 |
[0001] This application claims the benefit of the Korean Patent Application No. P2003-42074 filed in Korea on Jun. 26, 2003, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method of fabricating a liquid crystal display device and a wiring structure of the LCD, and more particularly, to a method of fabricating a liquid crystal display device and a wiring structure of the LCD in which a gate line and a data line are formed of a low resistance metal.
[0004] 2. Description of the Related Art
[0005] Recently, as modern society is rapidly changing to an information-oriented society, display techniques for processing a large amount of information and displaying images are actively advancing. In particular, flat panel liquid crystal displays (LCD) have been gaining in popularity due to advantageous characteristics such as slimness, lightweight, low power consumption requirements and the like. Of these, a thin film transistor liquid crystal display device (TFT-LCD) having superior color reproduction and slimming has been developed.
[0006] Generally, the LCD uses optical anisotropy and polarization of liquid crystal for its operation. Liquid crystal molecules with a thin and long structure have directionality in their configuration. Hence, by applying an electric field to the liquid crystal molecules, it is possible to control the alignment direction of the liquid crystal molecules.
[0007] To this end, by arbitrarily controlling the alignment direction of the liquid crystal molecules, the alignment of the liquid crystal molecules is varied and a polarized light is modulated by the optical anisotropy of the liquid crystal, thereby displaying image information.
[0008] Recently, an active matrix LCD (AM-LCD) in which the aforementioned thin film transistors and pixel electrodes connected to the thin film transistors are arranged in a matrix configuration is gaining popularity due to its high resolution and superior moving picture reproducing capability.
[0009] FIG. 1 is a plane view illustrating a pixel structure of a related art LCD.
[0010] Referring to FIG. 1 , a plurality of gate lines 10 for applying a driving signal are arranged on a thin film transistor substrate 1 of an LCD. A plurality of data lines 30 are arranged on the thin film transistor substrate and cross the gate lines perpendicularly. A plurality of pixel regions are defined by the gate lines 10 and the data lines 30 .
[0011] In a unit pixel region defined by the pair of gate lines 10 and the pair of data lines 30 , a thin film transistor (TFT) serving as a switching element is arranged.
[0012] The TFT has a structure in which a gate insulating layer, a semiconductor layer 50 consisting of an amorphous silicon (a-Si) layer and an impurity-doped amorphous silicon (n+a-Si) layer, a source electrode 60 a and a drain electrode 60 b are formed on a gate electrode 10 a branched from the gate line 10 .
[0013] The drain electrode 60 b of the TFT is electrically connected with a pixel electrode 100 through a contact hole 70 within the unit pixel region defined by the gate line 10 and the data line 30 .
[0014] Recently, as the resolution and screen sizes of the LCD have increased, the use of a metal with decreased resistance as the gate line and the data line has become more desirable. To enable use of the resistance metal, methods of fabricating the LCD using such a metal are being developed.
[0015] FIGS. 2A and 2B are sectional views illustrating a stack structure of a gate electrode in a fabrication method of an LCD according to a related art. Specifically, FIG. 2A shows a metal line on a substrate is formed of a single metal layer such as molybdenum (Mo) or chromium (Cr). The metal line formed of Mo or Cr is able to be chemically etched in a simple manner.
[0016] The process of forming the gate line is performed like in the process of forming the gate line of a general LCD. In other words, a metal layer of Mo or Cr is deposited on a cleaned substrate 200 . A photoresist film is coated on the metal layer, and is exposed and developed using a mask, thereby forming a photoresist pattern. The metal film is etched by using the photoresist pattern as an etch mask, thereby forming a gate line and a gate electrode 201 at the same time.
[0017] FIG. 2B shows a gate line has a double layered structure consisting of an Mo metal layer and an Al alloy layer. Referring to FIG. 2B , an Al alloy layer 301 is deposited on a substrate 300 , and then an Mo metal layer 301 a is deposited on the Al alloy layer 301 .
[0018] Since the Al alloy layer 301 has superior adhesion to the substrate and low resistance characteristics compared with the Mo metal layer 301 a, the double layered structure is superior in resistance characteristic to the single layer structure of Mo or Cr shown in FIG. 2A .
[0019] The Mo metal layer 301 a continuously deposited on the Al alloy layer 301 prevents an aluminum oxide (Al 2 O 3 ) layer from being formed on the Al alloy layer 301 , thereby decreasing a contact resistance between gate pad and pixel electrode to be formed later.
[0020] Also, the Mo metal layer 301 a prevents the Al alloy layer 301 from being damaged while a photolithography process of the semiconductor layer and the metal layer is performed.
[0021] FIGS. 3A and 3B are sectional views illustrating a fabrication method of an LCD, and structures of source and drain electrodes the array substrate according to a related art. Specifically, FIG. 3A shows that a source electrode 205 a and a drain electrode 205 b are formed above the gate electrode 201 shown in FIG. 2A , thereby forming a TFT.
[0022] The fabrication method of the TFT will now be described in more detail.
[0023] A gate insulating layer 202 is formed on the gate electrode 201 formed of a single metal layer and a transparent substrate 200 . Thereafter, a semiconductor layer 203 , 204 is formed on a resultant structure of the transparent substrate 200 by depositing an amorphous silicon (a-Si) layer 203 and an impurity-doped amorphous silicon (n+a-Si) layer 204 .
[0024] Next, a single metal layer of Mo or Cr is deposited on the semiconductor layer 204 and is then etched, thereby forming a source electrode 205 a and a drain electrode 205 b. By the above processes, a thin film transistor having electrodes made of the aforementioned signal metal layer can be formed.
[0025] Unlike in the above, FIG. 3B shows that a source electrode and a drain electrode are formed above the gate electrode shown in FIG. 2B . That is, FIG. 3B shows that each of the electrodes of a TFT is formed in a double layered structure consisting of an Mo metal layer and an Al alloy layer.
[0026] The fabrication method of the TFT will now be described in more detail.
[0027] A gate insulating layer 302 and a semiconductor layer 303 , 304 are sequentially formed on a substrate 300 and a gate electrode 301 , 301 a having a double layered structure consisting of an Mo metal layer 301 a and an Al alloy layer 301 . Next, an Mo metal layer 306 , 307 and an Al alloy layer are sequentially formed on the semiconductor layer 303 , 304 and are then etched, thereby forming a source electrode 305 a and a drain electrode 305 b, each having a triple layered structure consisting of the Mo metal layer 306 , 307 and the Al alloy layer.
[0028] In the above method, the Mo metal layer 301 a, 306 , 307 may replaced by a Cr metal layer.
[0029] The Al alloy is generally used as a material of the gate line, and has a relatively low resistance, thereby enabling a rapid signal transmission.
[0030] The Mo (or Cr) metal layer formed on the source electrode 305 a and the drain electrode 305 b prevents an aluminum oxide (Al 2 O 3 ) layer from being formed on the Al alloy layer 307 , thereby decreasing a contact resistance between the source/drain electrode and the pixel electrode connected to a data pad later.
[0031] Also, the Mo (or Cr) metal layer functions as a buffer layer for preventing the Al alloy layer 301 from being damaged while a photolithography process of the semiconductor layer and the metal layer is performed.
[0032] However, since the single Mo or Cr layer, and the double layers of the Mo or Cr layer and the Al alloy layer are have a high resistance, it is difficult to use them in an LCD with a high resolution of greater than UXGA (1600×1200) level.
[0033] Thus, if the resistance of the electrodes or signal lines is not sufficiently low, a signal transmission delay and a signal transmission loss may be caused.
SUMMARY OF THE INVENTION
[0034] A method of fabricating a liquid crystal display device and a wiring structure of the LCD are presented that employ a low resistance wiring structure and permit high resolution and large-sized screen to be fabricated.
[0035] A liquid crystal display device and fabrication method are presented that can minimize loss of the semiconductor layer by reducing a height difference in a stepped portion of the semiconductor layer.
[0036] As embodied and broadly described herein, there is provided a method of fabricating a liquid crystal display device is provided. The method includes: sequentially forming an aluminum alloy layer and a copper metal layer on a substrate; forming a photoresist pattern on the copper metal layer and etching the copper metal layer and the underlying aluminum alloy layer to form a gate line; depositing and etching a gate insulating layer, an amorphous silicon layer and an impurity-doped amorphous silicon layer to form a semiconductor layer; sequentially forming and etching an aluminum alloy layer and a copper metal layer on a resultant structure of the substrate including the semiconductor layer to form a data line, a source electrode and a drain electrode; forming a passivation layer on a resultant structure of the substrate including the data line, the source electrode and the drain electrode, and forming a contact hole and a pad opening in the passivation layer; and depositing a transparent conductive thin film on a resultant structure of the substrate including the passivation layer having the contact hole and the pad opening.
[0037] According to another aspect of the present invention, there is provided a wiring structure of an LCD including a gate line, a data line, and a thin film transistor, the thin film transistor having a gate electrode, a source electrode and a drain electrode, wherein each of the gate line, the data line, the gate electrode, the source electrode, and the drain electrode is formed in a double layers of an aluminum alloy layer and a copper metal layer.
[0038] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0040] FIG. 1 is a plane view illustrating a pixel structure of a related art LCD;
[0041] FIGS. 2A and 2B are sectional views illustrating a stack structure of a gate electrode in a fabrication method of an LCD according to a related art;
[0042] FIGS. 3A and 3B are sectional views illustrating a fabrication method of an LCD, and structures of source and drain electrodes the array substrate according to a related art;
[0043] FIG. 4 is a sectional view illustrating a structure of a gate line in an LCD according to the present invention;
[0044] FIG. 5 is a sectional view illustrating a fabrication method of an LCD and a source/drain structure of the LCD according to the present invention;
[0045] FIGS. 6A through 6C are sectional views illustrating a fabrication method of an LCD according to the present invention;
[0046] FIG. 7A is a schematic view illustrating a sectional structure of electrodes of an LCD formed by a continuous deposition;
[0047] FIG. 7B is a schematic view illustrating a sectional structure of electrodes of an LCD formed by a non-continuous deposition;
[0048] FIG. 8 is a graph illustrating variation in specific resistance when thermally annealing the electrodes fabricated as in FIGS. 7A and 7B ; and
[0049] FIG. 9 is a graph illustrating variation in specific resistance with respect to the thickness of the electrodes fabricated as in FIGS. 7A and 7B .
DETAILED DESCRIPTION OF THE INVENTION
[0050] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0051] FIG. 4 is a sectional view illustrating a structure of a gate line in an LCD according to an embodiment of the present invention.
[0052] Referring to FIG. 4 , an inventive LCD includes a gate line having a double layered structure consisting of a copper metal layer 501 a and an aluminum alloy layer 501 .
[0053] To form the gate line, an aluminum alloy layer 501 is deposited on a transparent substrate 300 and a copper metal layer 501 a is deposited on the aluminum alloy layer 501 in an identical chamber. Alternatively, the aluminum alloy layer 501 is first deposited, is exposed to air, and then the copper metal layer 501 a is deposited in a copper film deposition chamber.
[0054] The aluminum alloy layer 501 is formed thinner than the copper metal layer 501 a because the resistance of the double gate line is dependent on the thickness of the copper metal layer 501 a and the thickness of the aluminum alloy layer 501 . Detailed description relating to the resistance will be described later with reference to FIGS. 8 and 9 .
[0055] Thus, since the gate line is formed of the double layered structure of the copper metal layer 501 a and the aluminum alloy layer 501 , the gate line can be employed to create a high resolution LCD having low resistance line characteristics.
[0056] FIG. 5 is a sectional view illustrating a fabrication method of an LCD and a source/drain structure of the LCD according to an embodiment of the present invention.
[0057] Referring to FIG. 5 , a gate electrode of a thin film transistor of an LCD has a double layered structure consisting of an aluminum alloy layer 501 and a copper metal layer 501 a. A gate insulating layer 502 is formed on the gate electrode and a transparent substrate 500 . Thereafter, a semiconductor layer 503 , 504 , a source electrode 505 a and a drain electrode 505 b each including an aluminum alloy layer 506 are formed on a resultant structure of the transparent substrate 500 .
[0058] In the forming of the source and drain electrode layers 505 a and 505 b as the double layered structure including the aluminum alloy layer 506 , the aluminum alloy layer 506 and the copper metal layer 505 a, 505 b are formed by a continuous deposition or a non-continuous deposition. At this time, to allow the double layers to have a low resistance, the source and drain electrode layer 505 a, 505 b made of copper metal is formed thicker than the aluminum alloy layer 506 .
[0059] The semiconductor layer 503 , 504 includes an unintentionally doped amorphous silicon (a-Si) layer 503 and an impurity-doped amorphous silicon (n+a-Si), which are formed on the gate insulating layer 502 .
[0060] Next, a fabrication method of an LCD according to the present invention will now be described with reference to FIGS. 6A through 6C . FIGS. 6A through 6C are sectional views illustrating a fabrication method of an LCD according to an embodiment of the present invention.
[0061] First, referring to FIG. 6A , an aluminum alloy layer 501 is deposited on a transparent substrate 500 and then a copper metal layer 501 a is deposited on the aluminum alloy layer 501 . At this time, the copper metal layer 501 a and the aluminum alloy layer 501 can be continuously deposited in an identical chamber. Alternatively, the aluminum alloy layer 501 and the copper metal layer 501 a can be deposited in a non-continuous deposition method. In other words, the aluminum alloy layer 501 is first deposited, is exposed to air, and then the copper metal layer 501 a is deposited inside the chamber where the copper metal layer deposition has been deposited.
[0062] The aluminum alloy layer 501 includes an aluminum layer, or an aluminum alloy layer containing a conductive metal element. The conductive metal element can be alloyed with aluminum.
[0063] Next, a photoresist film is coated on an entire surface of a resultant structure of the substrate 500 , and is then patterned by a photolithography process including exposing, developing and etching, thereby forming a gate line 501 , 501 a.
[0064] Since the double layers of the copper layer 501 a and the aluminum layer 501 are used as the gate line, an etchant used for patterning the gate line may be different, but other elements except for the etchant are the same as those of the related art fabrication method of the LCD.
[0065] Next, referring to FIG. 6B , after the gate pattern including the gate line and the gate electrode is formed, a gate insulating layer 502 , an unintentionally doped amorphous silicon (a-Si) layer 503 , an impurity-doped amorphous silicon (n+a-Si) layer 504 are sequentially deposited on a resultant structure of the substrate 500 including the gate pattern, and are patterned to form a semiconductor layer including an unintentionally doped amorphous silicon (a-Si) layer pattern 503 and an impurity-doped amorphous silicon (n+a-Si) layer pattern 504 .
[0066] Next, referring to FIG. 6C , after the semiconductor layer is formed, double layers consisting of an aluminum layer 506 and a copper metal layer are deposited by a continuous deposition or a non-continuous deposition like in the deposition of the gate pattern.
[0067] The deposited double layers are patterned by a photolithography process including an exposing operation and an etching operation, thereby forming a source electrode 505 a and a drain electrode 505 b.
[0068] Thereafter, although not shown in the drawings, a passivation layer is formed on a resultant structure of the substrate including the source electrode 505 a and the drain electrode 505 b, and contact holes exposing the drain electrode 505 b and the source electrode 505 a are formed in the passivation layer. Then, an ITO thin film is deposited on a resultant structure of the substrate including the passivation layer, and is then patterned to form a pixel electrode, thereby completing a thin film transistor of an LCD.
[0069] As described above, since the gate line, the gate electrode, the data line, the source electrode and the data electrode are all formed in double layers of aluminum layer and copper layer, the LCD has an effective low resistance wiring.
[0070] Next, when the double layers of aluminum layer and copper layer are formed in an identical chamber by continuous deposition, and when the double layers of aluminum layer and copper layer are formed by the non-continuous deposition method including depositing the aluminum layer, exposing the deposited aluminum layer to air, and then depositing the copper layer, variation in resistance will now be described.
[0071] FIG. 7A is a schematic view illustrating a sectional structure of electrodes of an LCD formed by a continuous deposition.
[0072] Referring to FIG. 7A , an aluminum alloy layer 602 is deposited on a substrate 601 at a thickness of 200 Å. The deposited aluminum alloy layer 602 is exposed to air, and then a copper metal layer 604 is deposited thereon. An aluminum oxide layer 603 having a chemical formula of Al 2 O 3 is formed between the aluminum alloy layer 602 and the copper metal layer 604 .
[0073] The aluminum oxide layer 603 has a thickness of a few Å. The non-continuous deposition method can maintain a low resistance without any variation in the total resistance, but has relatively low production yield due to processes being non-continuous.
[0074] FIG. 7B is a schematic view illustrating a sectional structure of electrodes of an LCD formed by a non-continuous deposition.
[0075] Unlike in FIG. 7A , FIG. 7B corresponds to continuously deposition of an aluminum alloy layer 702 and a copper metal layer 704 without an exposure of the aluminum alloy layer 702 . Since the aluminum alloy layer 702 is not exposed to air, the aluminum oxide layer is not formed, but a CuAl layer 703 is formed at a thickness of a few of tens Å due to a chemical reaction between the copper metal layer 704 and the aluminum alloy layer 702 .
[0076] Thus, if the aluminum alloy layer 702 and the copper metal layer 704 are deposited by the non-continuous deposition, resistivity increases due to thermal treatment and accordingly resistance may increase.
[0077] However, if the aluminum alloy layer 702 and the copper metal layer 704 are deposited by the continuous deposition without a stop in the processes, production efficiency increases.
[0078] FIG. 8 is a graph illustrating variation in specific resistance when thermally annealing the electrodes fabricated as in FIGS. 7A and 7B , and FIG. 9 is a graph illustrating variation in specific resistance with respect to the thickness of the electrodes fabricated as in FIGS. 7A and 7B .
[0079] Referring to FIG. 8 , if the aluminum alloy layer 602 is deposited on a substrate 601 , exposed to air, and then the copper metal layer 604 deposited thereon, as shown in FIG. 7A , the specific resistance does not vary appreciably and is essentially constant even after thermal annealing is performed. In other words, the low resistance of the copper layer is essentially maintained at a constant value.
[0080] However, if the aluminum alloy layer 702 and the copper metal layer 704 are continuously deposited in the same chamber as shown in FIG. 7B , specific resistance of the double layered electrode increases and accordingly the double layered electrode fails to maintain a low resistance.
[0081] When considering the above facts, it is noted that the fabrication method presented herein can employ both the continuous deposition and the non-continuous deposition. However, if the lowest resistance is desired for a high resolution LCD, it is more desirable to use the continuous deposition process.
[0082] Referring to FIG. 9 , the resistance of the double layered electrode increases as the thickness of the aluminum alloy layer increases, or as the thickness of the copper metal layer decreases.
[0083] Accordingly, when forming the wiring structure with a double layered electrode consisting of the aluminum alloy layer and the copper metal layer, the copper metal layer is made thick and the aluminum alloy layer is made thin.
[0084] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A method of fabricating a liquid crystal display device is provided. An aluminum alloy layer and a copper metal layer are sequentially formed on a substrate. A photoresist pattern is formed on the copper metal layer and the copper metal layer and the underlying aluminum alloy layer are etched to form a gate line. A gate insulating layer, an amorphous silicon layer and an impurity-doped amorphous silicon layer are deposited and then etched to form a semiconductor layer. An aluminum alloy layer and a copper metal layer are sequentially formed and etched on the structure to form a data line, a source electrode and a drain electrode. A passivation layer is formed and a contact hole and a pad opening are formed in the passivation layer. A transparent conductive thin film is deposited on this structure. | 7 |
[0001] This application claims priority to U.S. provisional Application Ser. No. 61/751,381, filed Jan. 11, 2013, which is herein incorporated by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to an electronic device package structure, and more particularly, to an electronic component package structure isolating moisture and a method for manufacturing the same.
[0004] 2. Description of Related Art
[0005] In the manufacturing process of electronic components, the electronic components require a packaging operation for use in various applications such as computers, mobiles or digital camera. Therefore, the reliability of the packaging of the electronic components directly affects the performance of electronic devices.
[0006] FIG. 1A is a schematic cross-sectional view of a general electronic device package structure 100 a . In FIG. 1A , an electronic chip 110 a is positioned on a substrate 120 a , and electrically connected to a bonding pad 130 a . The bonding pad 130 a is sandwiched between the electronic chip 110 a and the substrate 120 a . A first passivation layer 140 a is sandwiched between the bonding pad 130 a and the substrate 120 a . A conductive layer 150 a is formed on the electronic chip 110 a , and electrically connected to the bonding pad 130 a to form a T-contact. In which, the conductive layer 150 a has a first side end 151 a and a second side end 152 a opposite to the first side end 151 a , and the bottom surface of the second side end 152 a contacts the first passivation layer 140 a . Then, a second passivation layer 160 a covers the conductive layer 150 a . The first side end 151 a is exposed, and the second side end 152 a is exposed at a sidewall of the general electronic device package structure 100 a . A solder ball 170 a is formed on the first side end 151 a of the conductive layer 150 a.
[0007] In the general electronic device package structure, the second passivation layer only covers the conductive layer, but the second side end of the conductive layer is exposed at the sidewall of the general electronic device package structure. The moisture from the surrounding may enter into the electronic device package structure along the second side end of the conductive layer, causing the degradation of the T-contact, or even decreasing the performance of the general electronic device. Therefore, there is a need for an improved electronic device package structure and a method for manufacturing thereof to prevent the moisture of the surrounding entering into the improved electronic device package structure, so as to enhance the tolerance and reliability of the improved electronic device.
SUMMARY
[0008] For solving the aforementioned issues, one embodiment of the present disclosure is to provide an electronic device package structure isolating moisture. The electronic device package structure includes a substrate, an electronic chip, a bonding pad, a first passivation layer, a conductive layer, a second passivation layer and a solder ball.
[0009] The electronic chip is positioned on the substrate. The bonding pad is sandwiched between the substrate and the electronic chip and electrically connected to the electronic chip. The first passivation layer is sandwiched between the substrate and the bonding pad. The conductive layer is positioned on a sidewall of the electronic chip and electrically connected to the bonding pad, and has a first side end and a second side end opposite to the first side end. The bottom surface of the second side end contacts the first passivation layer. The second passivation layer is positioned on the conductive layer. The first side end of the conductive layer is exposed, and the second side end of the conductive layer is covered. The second passivation layer simultaneously contacts the top surface and sidewall of the conductive layer, and completely covers the second side end of the conductive layer with the first passivation layer. The solder ball is positioned on the exposed first side end of the conductive layer.
[0010] Another embodiment of the present disclosure is to provide a method for manufacturing an electronic device package structure. The method includes several operations. A semiconductor wafer is provided, and has several electronic chips thereon. A bonding pad is formed under and electrically connected to each of the electronic chips. A first passivation layer is formed under the bonding pad. A conductive layer is formed on a sidewall of each of the electronic chips, and electrically connected to the bonding pad. The conductive layer has a first side end and a second side end. The bottom surface of the second side end of the conductive layer contacts the first passivation layer. The conductive layer is disconnected from a conductive layer on a sidewall of the adjacent electronic chip. A second passivation layer is formed on the conductive layer. The first side end of the conductive layer is exposed, and the second side end of the conductive layer is covered. The second passivation layer simultaneously contacts the top surface and sidewall of the conductive layer, and completely covers the second side end of the conductive layer with the first passivation layer. A solder ball is formed on the first side end of the conductive layer. A disconnection area between the conductive layers of the adjacent electronic chips is diced to separate the electronic chips, so as to provide the electronic device package structure.
[0011] In the electronic device package structure, the second passivation layer simultaneously contacts the top surface and sidewall of the conductive layer, and completely covers the second side end of the conductive layer with the first passivation layer. The electronic device package structure may prevent the outside moisture entering into the electronic device package structure and reduce the degradation of the electronic device, so as to enhance the tolerance and reliability of the electronic device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0013] FIG. 1A is a schematic cross-sectional view of a general electronic device package structure 100 a;
[0014] FIG. 1B is a schematic cross-sectional view of an electronic device package structure 100 b according to one embodiment of the present disclosure;
[0015] FIG. 2A is a sub-pattern 200 a of a general mask for manufacturing a general conductive layer;
[0016] FIG. 2B is a sub-pattern 200 b of a mask for manufacturing a conductive layer according to one embodiment of the present disclosure;
[0017] FIG. 2C is a sub-pattern 200 c of a mask for manufacturing a conductive layer according to one embodiment of the present disclosure;
[0018] FIGS. 3A-3I are schematic cross-sectional views at various stages of fabricating an electronic device package structure according to one embodiment of the present disclosure; and
[0019] FIGS. 4A-4E are schematic cross-sectional views at various stages of fabricating an electronic device package structure according to one embodiment of the present disclosure.
DETAILED DESCRIPTION
[0020] The embodiments of the transparent conductive structure and a method for manufacturing the same of the present disclosure are discussed in detail below, but not limited the scope of the present disclosure. The same symbols or numbers are used to the same or similar portion in the drawings or the description. And the applications of the present disclosure are not limited by the following embodiments and examples which the person in the art can apply in the related field.
[0021] The singular forms “a,” “an” and “the” used herein include plural referents unless the context clearly dictates otherwise. Therefore, reference to, for example, a metal layer includes embodiments having two or more such metal layers, unless the context clearly indicates otherwise. Reference throughout this specification to “one embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Further, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be appreciated that the following figures are not drawn to scale; rather, the figures are intended; rather, these figures are intended for illustration.
[0022] FIG. 1B is a schematic cross-sectional view of an electronic device package structure 100 b according to one embodiment of the present disclosure. In FIG. 1B , an electronic chip 110 b is positioned on a substrate 120 b , and electrically connected to a bonding pad 130 b . The bonding pad 130 b is sandwiched between the electronic chip 110 b and the substrate 120 b . A first passivation layer 140 b is sandwiched between the bonding pad 130 b and the substrate 120 b . A conductive layer 150 b is formed on the electronic chip 110 b , and electrically connected to the bonding pad 130 b to form a T-contact. In which, the conductive layer 150 b has a first side end 151 b and a second side end 152 b opposite to the first side end 151 b , and the bottom surface of the second side end 152 b contacts the first passivation layer 140 b . Then, a second passivation layer 160 b covers the conductive layer 150 b . The first side end 151 b of the conductive layer 150 b is exposed, and the second side end 152 b of the conductive layer 150 b is covered. A solder ball 170 b is formed on the first side end 151 b of the conductive layer 150 b . In which, the second passivation layer 160 b simultaneously contacts the top surface and sidewall of the conductive layer 150 b , and completely covers the second side end 152 b of the conductive layer 150 with first passivation layer 140 b.
[0023] According to one embodiment of the present disclosure, the electronic chip 110 b includes an integrated circuit device, a photoelectric device, a microelectromechanical (MEM) device, a surface acoustic wave (SAW) device and a combination thereof.
[0024] According to one embodiment of the present disclosure, the first passivation layer 140 b includes epoxy resin, polyimide (PI) resin, silicon oxide, metal oxide or silicon nitride.
[0025] According to one embodiment of the present disclosure, the conductive layer 150 b includes copper (Cu), aluminum (Al), nickel (Ni), gold (Au) or a combination thereof.
[0026] According to one embodiment of the present disclosure, the second passivation layer 160 b includes epoxy resin, polyimide (PI) resin, silicon oxide, metal oxide or silicon nitride.
[0027] In FIG. 1B , the electronic device package structure 100 b further includes a barrier layer 180 sandwiched between the substrate 120 b and the electronic chip 110 b . According to one embodiment of the present disclosure, the bonding pad 130 b and the barrier layer 180 are on the same surface. According to one embodiment of the present disclosure, the barrier layer 180 includes epoxy resin, polyimide (PI) resin, silicon oxide, metal oxide or silicon nitride.
[0028] In FIG. 1B , the electronic device package structure 100 b further includes an adhesive layer 190 sandwiched between the conductive layer 150 b and the electronic chip 110 b . According to one embodiment of the present disclosure, the adhesive layer 190 includes epoxy resin, polyimide (PI) resin, silicon oxide, metal oxide or silicon nitride.
[0029] FIG. 2A is a sub-pattern 200 a of a general mask for manufacturing a general conductive layer. In FIG. 2A , the sub-pattern 200 a of the general mask has a plurality of light transmissive areas (white portion) and at least one shading area (oblique portion), and a sub-pattern 210 a and a sub-pattern 220 a are adjacent sub-patterns. In which, one of the light transmissive areas of the sub-pattern 210 a connects one of the light transmissive areas of the sub-pattern 220 a.
[0030] FIG. 2B is a sub-pattern 200 b of a mask for manufacturing a conductive layer according to one embodiment of the present disclosure. In FIG. 2B , the sub-pattern 200 b of the mask has a plurality of light transmissive areas (white portion) and at least one shading area (oblique portion), and a sub-pattern 210 b and a sub-pattern 220 b are adjacent sub-patterns. In which, the sub-pattern 210 b and the sub-pattern 220 b have a separating channel 230 therebetween. The separating channel 230 is part of the shading area, so as to separate the light transmissive areas of the sub-pattern 210 b and the light transmissive areas of the sub-pattern 220 b.
[0031] FIG. 2C is a sub-pattern 200 c of a mask for manufacturing a conductive layer according to one embodiment of the present disclosure. In FIG. 2C , the sub-pattern 200 c of the mask has a plurality of shading areas (oblique portion) and at least one light transmissive area (white portion), and a sub-pattern 210 c and a sub-pattern 220 c are adjacent sub-patterns. In which, the sub-pattern 210 c and the sub-pattern 220 c have a separating channel 240 therebetween. The separating channel 240 is part of the light transmissive area, so as to separate the shading areas of the sub-pattern 210 c and the shading areas of the sub-pattern 220 c.
[0032] FIGS. 3A-3I are schematic cross-sectional views at various stages of fabricating an electronic device package structure according to one embodiment of the present disclosure. In FIG. 3A , electronic chips 310 are positioned on a substrate 320 , and electrically connected to a bonding pad 330 , wherein the bonding pad 330 is sandwiched between the electronic chips 310 and the substrate 320 . A first passivation layer 340 is sandwiched between the bonding pad 330 and the substrate 320 . A conductive layer 350 is formed on the electronic chip 310 , and electrically connected to the bonding pad 330 . In which, the bottom surface of the conductive layer 350 contracts the first passivation layer 340 . In FIG. 3A , a trench 360 is formed to separate an electronic device package substrate 300 a and an adjacent electronic device package substrate 300 b.
[0033] According to one embodiment of the present disclosure, the method further includes forming a barrier layer sandwiched between the substrate and the electronic chips. According to one embodiment of the present disclosure, the method further includes forming an adhesive layer sandwiched between the electronic chips and the conductive layer.
[0034] In FIG. 3B , a photo-resist layer 370 a is formed on the conductive layer 350 . Then, a developing process is performed by applying the mask having the sub-pattern as shown in FIG. 2B or 2 C, to form a photo-resist layer 370 b having the sub-pattern as the mask, as shown in FIG. 3C . According to one embodiment of the present disclosure, the photo-resist layer 370 b is formed by applying a negative photo-resist agent and a clear mask, wherein the clear mask has the sub-pattern as shown in FIG. 2B . According to one embodiment of the present disclosure, the photo-resist layer 370 b is formed by applying a positive photo-resist agent and a dark mask, wherein the dark mask has the sub-pattern as shown in FIG. 2C .
[0035] In FIG. 3D , a photo-resist layer 370 b is removed to form a photo-resist layer 370 c having a recess in the trench 360 , so that part of the conductive layer 350 is exposed. It is noted that, the recess of the photo-resist layer 370 c is corresponded to the separating channel 230 or 240 of the sub-pattern of the mask as shown in FIG. 2B or 2 C.
[0036] In FIG. 3E , the exposed conductive layer 350 is etched, so as to expose part of the first passivation layer 340 in the trench 360 to form conductive layers 350 a and 360 b . In which, the conductive layer 350 a has a first side end 351 a and a second side end 352 a , and the conductive layer 350 b has a first side end 351 b and a second side end 352 b . The second side end 352 a of the conductive layer 350 a is disconnected from the second side end 352 b of the conductive layer 350 b . However, in general methods, there is no an etching process of a conductive layer, so that the conductive layer of the general electronic device package structure is connected to a conductive layer of the adjacent electronic device package structure.
[0037] In FIG. 3F , after the photo-resist layer 370 c (see FIG. 3E ) is removed, the conductive layers 350 a and 350 b are exposed. Then, metal is deposited on the conductive layers 350 a and 350 b to thicken the conductive layers 350 a and 350 b , as shown in FIG. 3G .
[0038] In FIG. 3H , a second passivation layer 380 is formed on the conductive layers 350 a and 350 b . First side ends 351 a and 351 b of the conductive layers 350 a and 350 b are exposed, and second side ends 352 a and 352 b of the conductive layers 350 a and 350 b are covered. In which, the second passivation layer 380 simultaneously contacts top surfaces and sidewalls of the conductive layers 350 a and 350 b , and completely covers the second side ends 352 a and 352 b of the conductive layers 350 a and 350 b with the first passivation layer 340 . Then, a solder ball 390 a is formed on the first side end 351 a of the conductive layer 350 a , and a solder ball 390 b is formed on the first side end 351 b of the conductive layer 350 b . By dicing along the trench 360 , individual electronic device package structure 300 a and 300 b are provided, as shown in FIG. 3I .
[0039] FIGS. 4A-4E are schematic cross-sectional views at various stages of fabricating an electronic device package structure according to one embodiment of the present disclosure. In FIG. 4A , followed the structure as shown in FIG. 3B , a developing process is performed by applying the mask having the sub-pattern as shown in FIG. 2B or 2 C, to form a photo-resist layer 410 a having the sub-pattern as the mask. According to one embodiment of the present disclosure, the photo-resist layer 410 a is formed by applying a positive photo-resist agent and a clear mask, wherein the clear mask has the sub-pattern as shown in FIG. 2B . According to one embodiment of the present disclosure, the photo-resist layer 410 a is formed by applying a negative photo-resist agent and a dark mask, wherein the dark mask has the sub-pattern as shown in FIG. 2C .
[0040] In FIG. 4B , a photo-resist layer 410 a (see FIG. 4A ) is removed to form a photo-resist layer 410 b having an embossment in the trench 360 , so that part of the conductive layer 350 is exposed. It is noted that, the embossment of the photo-resist layer 410 b is corresponded to the separating channel 230 or 240 of the sub-pattern of the mask as shown in FIG. 2B or 2 C.
[0041] In FIG. 4C , metal is deposited on the exposed conductive layers 350 to thicken the conductive layers 350 . Then, the photo-resist layer 410 b is removed to form the conductive layers 350 having a recess, as shown in FIG. 4D .
[0042] In FIG. 4E , the recess of the conductive layer 350 is etched to expose part of the first passivation layer 340 in the trench 360 , so as to form the conductive layers 350 a and 360 b . In which, the conductive layer 350 a has a first side end 351 a and a second side end 352 a , and the conductive layer 350 b has a first side end 351 b and a second side end 352 b . The second side end 352 a of the conductive layer 350 a is disconnected from the second side end 352 b of the conductive layer 350 b.
[0043] Then, as shown in FIGS. 3H-3I , the second passivation layer 380 , the solder balls 390 a and 390 b , and the dicing process along the trench 360 are sequentially formed, so as to separate into the individual electronic device package structure 300 a and 300 b.
[0044] It is noted that, the first passivation layer contacts the bottom surface of the second side end of the conductive layer, and the second passivation layer simultaneously contacts the top surface and sidewall of the conductive layer, so that the first passivation layer and the second passivation layer completely covers the second side end of the conductive layer to prevent moisture entering into the electronic device package structure. Because the degradation of the electronic device is reduced, the reliability of the electronic device may be enhanced.
[0045] Although embodiments of the present disclosure and their advantages have been described in detail, they are not used to limit the present disclosure. It should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the present disclosure. Therefore, the protecting scope of the present disclosure should be defined as the following claims. | The invention provides an electronic device package and method for manufacturing thereof. The electronic device package includes a substrate, an electronic chip, a bonding pad, a first passivation layer, a conductive layer, a second passivation layer, and a solder ball. The conductive layer has a first side end and a second side end, and the solder ball is positioned on the first side end of the conductive layer. The second passivation layer contacts with both the upper surface and the sidewall of the second side end of the conductive layer, and the first passivation layer contacts with the lower surface of the second side end of the conductive layer, so as to completely encapsulate the second end of the conductive layer. The electronic device package accordingly prevents the moisture penetration and to enhance the reliability of the electronic device. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is the US national phase of International Patent Application No. PCT/EP2013/068971, filed Sep. 13, 2013, which application claims priority to German Application No. 102012217572.5, filed Sep. 27, 2012. The priority application, DE 102012217572.5, is hereby incorporated by reference.
FIELD OF THE DISCLOSURE
[0002] The present invention relates to an operator system for a machine, in particular a beverage processing machine, to a mobile operator device, a carrying device and a signal emitter.
BACKGROUND
[0003] When servicing beverage processing plants, a user normally operates the individual machines via an operator system. The operator system can e.g. be used for triggering individual sequences of operations in the machine, adjusting parameters and/or receiving alarm and/or warning signals. To this end, stationary operator devices and, to an increasing extent, also mobile operator devices are used, the mobile operator devices being compatible with the entire plant and adapted to be used for different machines. The user can here take along a mobile operator device to the respective machine and can simultaneously execute or supervise functions of other machines.
[0004] The user, for example, puts down the mobile operator device in the area of a specific machine and, while carrying out repair work, he will be able to keep an eye on the display of the mobile operator device for reading information thereon. Likewise, he will be able to control individual components of the machine via the mobile operator device so as to carry out the repair. In addition, alarm and warning signals of the machine in question and/or of other machines will be displayed to the user, who can thus decide whether a more urgent repair of some other machine should perhaps be given preference.
[0005] Such operator systems with mobile operator devices often prove to be non-ergonomic in practice, since the user has to carry them in his hand and since, normally, there are no possibilities of depositing them in a stable manner on the machine during servicing. After the repair of a machine it may, moreover, easily happen that the mobile operator device is left behind on the machine and that the user has to return in order to get it. In addition, the user may easily fail to hear alarm and/or warning signals, since, during servicing, he works e.g. in the interior of the machine or in noisy surroundings.
[0006] Therefore, it is the object of the present invention to provide an operator system that is more ergonomic to handle.
SUMMARY OF THE DISCLOSURE
[0007] This object is achieved by operator system for a machine, in particular for a beverage processing machine, having a mobile operator device for the machine, a signal emitter for reporting alarm and/or warning signals, and a carrying device for the operator device, wherein the operator device comprises a coupling element for attaching to the machine and/or to the carrying device and a sensor for transmitting alarm and/or warning signals, wherein the signal emitter comprises an attachment element for attaching to an article of clothing and/or to a body part of a user and a receiver for the alarm and/or warning signals, and wherein the carrying device comprises a mounting element for attaching to an article of clothing and/or to a body part of the user and a receptacle for the operator device.
[0008] Due to the fact that the operator device comprises a coupling element for attaching to the machine and/or to the carrying device, the user, when carrying the operator device, can attach it to the receptacle of the carrying device on the one hand, whereas, during servicing, he can attach it to the machine. Hence, the user need not hold the operator device in his hands, neither during servicing nor when he carries it to the next machine, i.e. his hands will be free for other activities. Simultaneously, the coupling element for attaching to the machine allows the operator device to be held on the machine in a stable manner, while the user's hands are free for repair work. At the same time, the user may wear, e.g. on his arm, a signal emitter, which informs him of alarm and/or warning signals from the operator device. These alarm and/or warning signals can thus be transmitted from the transmitter of the operator device to the receiver of the signal emitter, where they can be announced to the user. Due to the fact that the signal emitter is attached directly on an article of clothing and/or a body part of the user, the user will no longer fail to notice the alarm and/or warning signals. In addition, the operator device may also be outside the user's reach, the alarm and/or warning signals being, however, nevertheless announced via the signal emitter. The carrying device additionally allows easy transport of the operator device, without restraining the user from other activities.
[0009] Hence, the operator system according to the present invention supports the user in an ergonomic manner in operating and/or servicing the machine.
[0010] The operator system may be provided for a plant, in particular for a beverage processing plant. The plant may comprise at least one machine. The machine may be arranged in a beverage processing plant. The machine may comprise a computer-based machine control. The machine may be a beverage processing machine and/or a container treatment machine, which is especially a stretch blow molder, a rinser, a filler, a capper, a labeler and/or a packaging machine or some other beverage processing machine and/or some other container treatment machine.
[0011] The mobile operator device may comprise a microprocessor, a keyboard and/or a display, which may especially be touch-sensitive. Likewise, the mobile operator device may comprise individual control knobs. The mobile operator device may comprise a data interface for machine control of the machine, in particular a wireless data interface. The wireless data interface may be a Bluetooth interface or a WLAN interface. The mobile operator device may be a tablet computer or a smart phone. The coupling element for attaching to the machine and/or to the carrying device may be glued onto the housing as an additional element. Alternatively, the coupling element may be attached to the mobile operator device by a mounting bracket. The coupling element may comprise electric connection terminals by means of which signals are transmitted to the machine and/or the carrying device.
[0012] The signal emitter may comprise a wristband, a chain that can be worn around the neck, a clip and/or a clasp for attaching to the article of clothing and/or the body part of the user. The signal emitter may comprise a microprocessor and/or a battery for power supply. The power supply may here especially be provided for the receiver and/or the microprocessor.
[0013] The mounting element of the carrying device may be configured as a buckle, a clip or a clasp. The mounting element may especially be configured for attaching to a belt. The receptacle for the operator device may be a protective cover and/or a bag.
[0014] In the case of the operator system for a machine, the coupling element may comprise a magnet, a ferromagnetic metal element, a locking element and/or a Velcro fastener. The operator device can thus be attached to the machine particularly easily. For example, the operator device can be attached directly to a metal part of the machine by means of the magnet.
[0015] The signal emitter may comprise a vibrator, an acoustic signal emitter and/or an optical signal emitter. The vibrator imparts to the user an activation stimulus, which he can perceive independently of the noise in the surroundings. The same can also be achieved by the optical signal emitter. In addition, the user's attention can be drawn to the alarm and/or warning signals by the acoustic signal emitter, if he does not have direct visual contact with the signal emitter. The signal emitter may reproduce different types of alarm and/or warning signals as differently encoded vibration, audio and/or light signals. The different codes may have different intensities or rhythms. The optical signal emitter may display different types of alarm and/or warning signals with different colors. The optical signal emitter may comprise a display.
[0016] In the operator system, the transmitter and the receiver may comprise a wireless transmission unit for transmitting the alarm and/or warning signals as radio signals. This allows a particularly reliable and convenient mode of transmitting the alarm and/or warning signals. The wireless transmission unit may comprise a Bluetooth transmission device and/or a WLAN transmission device. In addition, the signal emitter may comprise a transmitter and the operator device may comprise a receiver, which are in particular assigned to the wireless transmission unit. The wireless transmission unit can thus be used for transmitting data from the operator device to the signal emitter as well as, vice versa, from the signal emitter to the operator device. For example, control commands can be transmitted from the signal emitter to the operator device in this way. Likewise, confirmation signals for the alarm and/or warning signals can be sent back from the signal emitter to the operator device. The signal emitter may here comprise keys.
[0017] The signal emitter may be a mobile phone. Thus, the mobile phone, which the user normally carries with him, is used as a signal emitter and the user need not carry any separate signal emitter. At the same time, the handling of the system can be simplified and the acquisition of the operator system is less cost-intensive. The mobile phone may here comprise a vibrator, an acoustic and/or an optical signal emitter. In addition, the mobile phone can display the message assigned to the alarm and/or warning signal on its display.
[0018] In the carrying device, the receptacle may be configured as a mating coupling for the coupling element, wherein said mating coupling is releasably or non-releasably connected to the mounting element, and, in particular, wherein said mating coupling and/or said mounting element comprise a magnet, a ferromagnetic metal element, a locking element or a Velcro fastener. The operator device can thus be coupled via its coupling element into the mating coupling of the carrying device in a particularly easy manner. In addition, the operator device can thus be retained on the carrying device particularly safely for the purpose of transport. The coupling element of the operator device can here be configured such that it can releasably be connected to the mating coupling and/or the machine. The coupling element may comprise a magnet and the mating coupling may comprise a ferromagnetic metal element. These components may also be arranged vice versa. Due to the magnetic force, it is particularly easy to releasably connect the coupling element to the ferromagnetic metal plate in the mating coupling of the carrying device.
[0019] The mobile operator device and the carrying device may be connected to one another via a connection band. The connection band can prevent the operator device from being left behind in the machine. The connection band may be a cord, a flat band or a chain. The connection band may comprise an elastic or a coil element. On the basis of this arrangement, the operator device, when carried, can be connected directly to the carrying device and, after having been detached, it can be connected indirectly via the connection band.
[0020] The mating coupling may be connected directly or indirectly to the mounting element via the connection band. After having been carried, the operator device can thus be disengaged from the mating coupling and can then be free or it can be removed from the mounting element together with the mating coupling and can remain reliably connected to the mounting element via the connection band. In other words, the user is able to decide, upon removing the operator device, whether or not the latter will then remain reliably connected to the mounting element through the connection band. In particular, the operator device can be protected against losing by means of the connection band.
[0021] A retaining projection on the mounting element may be configured to prevent disengagement of the mating coupling from the mounting element along one direction. Simultaneously, the mating coupling can be disengaged from the mounting element along a different direction. This provides in a particularly easy manner the possibility of leaving the mating coupling behind on the mounting element when the operator device is removed along one direction, but disengaging it therefrom when the removal takes place along a different direction.
[0022] A roll, in particular with a spring mechanism, may be configured to wind and unwind the connection band. This prevents the connection band from hanging down as a loose loop.
[0023] The roll may be arranged on the mounting element. The roll can thus be arranged in a particularly space-saving manner.
[0024] The signal emitter can be integrated in the carrying device. Since the carrying device is also attached to an article of clothing and/or a body part of the user, it may additionally accommodate the signal emitter and advance the alarm and/or warning signals to the user. Hence, the user need not attach a plurality of functional units in the area of his body and costs can be saved through the integration.
[0025] In addition, the present invention provides a mobile operator device for an operator system in particular for a beverage processing machine, wherein a coupling element for attaching to a machine and/or to a carrying device is formed, and wherein the operator device comprises a transmitter for transmitting alarm and/or warning signals to a signal emitter.
[0026] This allows the mobile operator device to be attached to the machine safely as well as in an ergonomically advantageous manner. In addition, the operator device can be attached to the carrying device and can be carried in an ergonomically particularly advantageous manner. Due to the fact that the operator device comprises a transmitter for transmitting alarm and/or warning signals to a signal emitter, the respective signals can be transmitted from the operator device to the signal emitter, if the user should not be in close vicinity to the mobile operator device. For example, a user can no longer hear the mobile operator device directly in particularly noisy surroundings, but the signal emitter, which is located in close vicinity to the user's body, can still be heard. The alarm and/or warning signals from the operator device can thus nevertheless be transmitted to the user.
[0027] The coupling element may comprise a magnet, a locking element and/or a Velcro fastener. The coupling element can thus be coupled to the machine and/or the carrying device particularly easily.
[0028] The present invention additionally provides a carrying device for an operator system wherein a mounting element for attaching to an article of clothing and/or to a body part of a user is provided, wherein a mating coupling is releasably or non-releasably connected to the mounting element and adapted to be coupled to a coupling element of a mobile operator device, and wherein the mating coupling is directly or indirectly connected to the mounting element via a connection band.
[0029] Due to the mounting element, the carrying device can be attached to an article of clothing and/or a body part of the user in a particularly simple manner. Simultaneously, the mating coupling can be coupled to the coupling element of the mobile operator device particularly easily and the operator device can thus be carried particularly easily. Simultaneously, the mating coupling can also be disengaged from the mounting element and is indirectly connected to the mounting element via the connection band. The mobile operator device is thus prevented from being left behind on a machine.
[0030] The mating coupling and/or the mounting element may comprise a magnet, a ferromagnetic metal element, a locking element and/or a Velcro fastener. Coupling between the mating coupling and the mounting element can thus be realized particularly easily. Simultaneously, a releasable connection between the mating coupling and the coupling element of the operator device can be established in a particularly easy manner.
[0031] The mating coupling may be connected to the mounting element directly or indirectly via a connection band. The connection band may be a cord, a flat band or a chain. The operator device coupled to the mating coupling can thus be prevented from being left behind on the machine by the user.
[0032] A retaining projection may be formed on the mounting element for preventing disengagement of the mating coupling from the mounting element along one direction. Thus, disengagement of the mating coupling can be prevented along one direction and, consequently, the coupling element of the operator device is detached from the mating coupling during this movement. Subsequently, the operator device is completely free. In a different direction, the operator device is detached from the mounting element together with the mating coupling, and the mating coupling can here remain connected to the mounting element via the connection band. Hence, the user can choose whether he protects the operator device against losing, when he removes the same.
[0033] A roll on the mounting element may be configured for winding and unwinding the connection band. In particular, the roll may comprise a spring mechanism. Hence, the connection band can be wound up particularly easily. This prevents the connection band from hanging down freely.
[0034] In addition, the present invention provides a signal emitter for an operator system according to claim 15 , wherein an attachment element for attaching to an article of clothing and/or to a body part of a user is formed and wherein the signal emitter comprises a receiver for receiving alarm and/or warning signals from an operator device for a machine.
[0035] The user can thus carry the signal emitter close to his body and, in the case of an alarm received by the operator device, he will be warned immediately.
[0036] The signal emitter may comprise a vibrator, an acoustic signal emitter and/or an optical signal emitter. Thus, the user can receive the alarm and/or warning signals in noisy surroundings. The signal emitter may be configured for emitting as a signal various alarm and/or warning signals with different intensities or rhythms, which can be adjusted especially by the user. The optical signal emitter may be configured for displaying various alarm and/or warning signals with different colors.
[0037] The signal emitter may be a mobile phone. Thus, an already existing mobile phone may be used for fulfilling the function of a signal emitter.
[0038] The signal emitter may be integrated in the carrying device. The user thus has to wear only one device on his body and costs can be saved through the integration.
[0039] The transmitter and the receiver may comprise a wireless transmission unit for transmitting the alarm and/or warning signals as radio signals. The alarm and/or warning signals can thus be transmitted in a particularly reliable manner and without direct visual contact.
[0040] In addition, the operator device may comprise a receiver and the signal emitter may comprise a transmitter for the signals. This allows the user to send a confirmation signal via the signal emitter to the operator device. For example, alarms may here be confirmed. The receiver in the operator device and the transmitter in the signal emitter may also comprise a wireless transmission unit. The wireless transmission unit may comprise a respective transmitter in the operator device and in the signal emitter.
[0041] Likewise, the operator device and/or the signal emitter may each comprise a Bluetooth and/or a WLAN transmitter. The operator device and/or the signal emitter can be connected to an existing network infrastructure in this way.
[0042] The operator system may comprise a separate camera and the operator device may be configured for displaying, on the user's demand, the picture of said separate camera on the display. The separate camera may be configured for imaging conditions at individual points of the machine. For example, it would be imaginable that the filling level of containers for preforms, caps, labels or of other containers is displayed or that critical points of the plant are displayed, at which malfunctions or other problems occur comparatively frequently. The separate camera may also be a mobile camera. Thus, its position can be changed at any time.
[0043] Additional features and advantages of the present invention will be explained in the following with reference to the exemplary figures, in which:
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0044] FIG. 1 shows a perspective view of an operator system;
[0045] FIG. 2 shows a side view of another operator system;
[0046] FIG. 3 a shows a side view of the operator system according to FIG. 2 , in which the operator device is removed from the carrying device in a first direction; and
[0047] FIG. 3 b shows a side of the operator system according to FIG. 2 , in which the operator device is removed from the carrying device in a second direction that is different from the direction of removal illustrated in FIG. 3 a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] FIG. 1 shows a perspective view of an operator system 1 according to the present invention. It can be seen that a user 6 stands in front of a machine 5 to be serviced. The machine 5 shown is here a beverage processing machine.
[0049] The user 6 wears a belt 61 having the carrying device 4 attached thereto. The carrying device 4 is here attached via the mounting element 41 , which is configured as a loop and through which the belt 61 is passed. The mounting element 41 has provided thereon a mating coupling 42 used for coupling the operator device 2 .
[0050] In addition, it can be seen that the operator device 2 is attached to the machine 5 . The coupling element 22 is here used for attaching the operator device 2 to the machine 5 . This coupling element 22 comprises here a magnet, which holds the operator device 2 on the metallic housing of the machine 5 in a particularly reliable manner. The operator device 2 can also be detached from the machine 5 by the user 6 . The operator device 2 additionally comprises a touch-sensitive display 21 which, via an operating software, offers the user 6 the possibility of entering data into the machine 5 and viewing respective messages. In addition, alarm and/or warning signals of the machine in question and of other machines can be received and confirmed in this way.
[0051] The operator device 2 is adapted to be coupled to the mating coupling 42 of the carrying device 4 via the coupling element 22 . To this end, the mating coupling 42 includes a ferromagnetic metal plate to which the magnet of the coupling element 22 adheres particularly well. If the user 6 wants to take along the operator device 2 to some other machine, he can take off the operator device 2 from the machine 5 and attach it to the mating coupling 42 of his carrying device 4 . This allows the user 6 to move on to the other machine in an ergonomically advantageous manner, without having to hold the operator device 2 in his hands.
[0052] In addition, the user 6 wears a signal emitter 3 on his wrist. The operator device 2 can here transmit the alarm and warning signals via a transmitter to a receiver in the signal emitter 3 . The signal emitter 3 includes a vibrator, which applies a vibrating signal to the wrist of the user 6 . The user 6 will thus be able to receive alarm and/or warning signals from the operator device 2 , if he is not able to look directly at the display 21 of the operator device 2 . For example, he will still be able to receive the alarm and warning signals, when he carries out a servicing operation within the machine 5 .
[0053] Hence, the operator system 1 shown in FIG. 1 allows servicing of machines 5 in a particularly ergonomic manner, since the operator device 2 can be attached to the machine 5 as well as to the carrying device 4 . The user 6 , in turn, has his hands free for servicing the machine 5 . In addition, the signal emitter 3 informs him of important events. The signal emitter 3 also emits a warning signal, if the user 6 should leave behind the operator device 2 on the machine 5 . Hence, the user need not walk a long distance for picking up the operator device 2 which he left behind.
[0054] FIG. 2 shows a side view of a further operator system 1 according to the present invention. The figure shows the operator device 2 , which, via the coupling element 22 , can be attached to a machine (which is here not shown) as well as to the carrying device 4 . The carrying device 4 is configured such that it can be attached to a belt of a user (not shown either) by means of the mounting element 41 . Also the signal emitter 3 is shown, by means of which alarm and warning signals from the operator device 2 can be signalized to the user. The signal emitter 3 can here be attached to the user's wrist.
[0055] The operator device 2 comprises a touch-sensitive display 21 on which the user can read messages as well as enter commands. The operator device 2 is connected to the machine via a wireless interface, said wireless interface comprising in particular a data interface between the operator device 2 and a machine control. It can also be seen that the operator device 2 comprises a transmitter 24 , which is part of a wireless transmission unit. The operator device 2 is thus able to emit alarm and warning signals as radio signals. In addition, a coupling element 22 including a first magnet 23 is provided on the back of the operator device. Alternatively, this may also be Velcro fastener.
[0056] The operator device 2 can be coupled to the mating coupling 42 of the carrying device 4 via the coupling element 22 and the first magnet 23 . In addition, the operator device 2 can also be attached to ferromagnetic metal parts of the machine in this way.
[0057] The mating coupling 42 comprises, on the side of the operator device, a ferromagnetic metal plate 43 to which the first magnet 23 adheres particularly well. On the other side, the mating coupling 42 comprises, in turn, also a second magnet 44 by means of which the mating coupling 42 can be attached to the mounting element 41 . To this end, also the mounting element 41 includes a ferromagnetic metal plate 45 to which the second magnet 44 adheres particularly well and from which it can also be detached. On the other side of the mounting element 41 , also a hook can be seen by means of which the mounting element can be hooked onto the user's belt.
[0058] In addition, the mating coupling 42 is connected to the mounting element 41 via a connection band 47 . This connection band 47 can be wound up automatically by means of a roll 48 , said roll 48 including a spring mechanism. In addition, the roll 48 is provided with a brake that can be activated and subsequently released by pulling the connection band 47 . The connection band 47 can thus be maintained in a specific, suitable length. In addition, the mounting element 41 comprises a retaining projection 46 , which will be explained in more detail hereinbelow making reference to FIG. 3A and 3B .
[0059] The signal emitter 3 can be attached to the user's wrist via the connection loop 35 . The connection loop 35 comprises here a closure mechanism. In addition, the signal emitter 3 comprises a receiver 34 for the alarm and warning signals from the operator device 2 . This receiver 34 is configured as a radio receiver and it is part of the wireless transmission unit. The receiver 34 is here able to receive and interpret the signals of the operator device 2 transmitted via radio. In addition, the signal emitter 3 comprises a vibrator 31 , an acoustic signal emitter 32 and an optical signal emitter 33 . The alarm and warning signals can thus be transmitted to the user as a particularly broad spectrum of activation stimuli. However, the signal emitter 3 may also offer only one of the three above-mentioned possibilities. The signal emitter 3 has here a particularly light and ergonomic structural design. Furthermore, the signal emitter 3 comprises a battery and a microprocessor for processing the alarm and warning signals.
[0060] In FIG. 3A and 3B , the operator system 1 according to FIG. 2 is shown, the operator device 2 being removed from the carrying device 4 in two different directions R 1 , R 2 .
[0061] In FIG. 3A it can be seen how the operator device 2 is removed from the carrying device 4 in a direction R 1 . The direction R 1 is here largely perpendicular to a planar retaining area 49 of the retaining projection 46 and parallel to the surface of the coupling element 22 , in particular to the magnet 23 . Due to the fact that the retaining projection 46 blocks the movement of the mating coupling 42 , the mating coupling 42 remains in the mounting element 41 . The magnet 23 is thus removed transversely from the respective counterplate 43 in the mating coupling 42 . At the same time, the connection band 47 remains in the roll 48 . The operator device 2 is thus fully released from the carrying device 4 and can now be positioned freely on the machine by the user.
[0062] FIG. 3B , however, shows that the operator device 2 is removed from the carrying device 4 in a direction R 2 . The direction R 2 is here substantially parallel to the planar retaining area 49 of the retaining projection 46 . The retaining projection 46 can thus not hold the mating coupling 42 in the mounting element 41 and the magnet 44 disengages from the respective counter-plate 45 of the mounting element 41 . The operator device 2 remains connected to the mounting element 41 via the mating coupling 42 and the connection band 47 . The operator device 2 is thus protected against losing. In addition, the connection band 47 unwinds from the roll 48 , so as to prevent a formation of loops that may become entangled.
[0063] The embodiments of the carrying device 4 for the operator system 1 in FIG. 2 , 3 A and 3 B thus allow the user to decide freely whether he removes the operator device 2 from the carrying device 4 with or without protection through the connection band 47 .
[0064] The features specified in the above-described embodiments are not limited to these special combinations and may also be provided in arbitrary other combinations. | An operator system for a machine, in particular for a beverage processing machine, having a mobile operator device for the machine, a signal emitter for reporting alarm and/or warning signals, and a carrying device for the operator device, wherein the operator device has a coupling element for attaching to the machine and/or to the carrying device and a transmitter for transmitting alarm and/or warning signals, wherein the signal emitter has an attachment element for attaching to an article of clothing and/or to a body part of a user and a receiver for the alarm and/or warning signals, and wherein the carrying device has a mounting element for attaching to an article of clothing and/or to a body part of the user and a receptacle for the operator device . | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of PCT International Patent Application No. PCT/NL/02/00572, filed on Sep. 2, 2002, designating the United States of America, and published, in English, as PCT International Publication No. WO 03/017845 A1 on Mar. 6, 2003, the contents of the entirety of which is incorporated by this reference.
TECHNICAL FIELD
[0002] This invention relates to a method for generating hardness information of tissue subject to a varying pressure. In particular, the method relates to a method for generating hardness information of the wall of a blood vessel or body cavity.
BACKGROUND
[0003] Such a method is known from European patent application EP-A 0 908 137. In this application, the strain (deformation) of vessel walls is derived with ultrasound from the relative displacement of a more inward layer and a more outward layer of the vessel wall as a result of the pressure varying through the heartbeat. These relative displacements are (at an assumed equal speed of sound in the medium) equal to the difference of relative time delays of the ultrasound beam, measured at two times.
[0004] The relative time delay can be measured by correlating with each other sound signals obtained consecutively over time from one specific direction and deriving the relevant time delay from a correlation optimum. At this optimum, therefore, two signals consecutive over time are maximally correlated when the time difference between the respective signals is equal to the relevant time delay. By taking the difference of time delays measured at two different times and relating this to the time difference between the measuring times, it is possible to derive the degree of strain of the vessel wall in the direction of the sound beam as a result of pressure changes induced by the heartbeat.
[0005] By measuring the local relative displacements with a measuring beam in a specific direction and performing this measurement in a measuring plane oriented transversely to the vessel wall, it is possible to display elasticity information about respective measuring positions in the measuring plane. Furthermore, by measuring an average relative displacement along the above directions, a so-called palpogram can be composed, which is indicative of the hardness of the vessel wall in the plane in which the vessel wall cuts the measuring plane. The information derivable from such an elastogram/palpogram is important to identify and characterize plaques on the vessel walls. The composition of plaques can be important to the assessment of their injuriousness to health.
[0006] Such information is often not derivable from a conventional echogram, since the image of high-risk cannot be distinguished from less high-risk plaques.
[0007] Moreover, practical and theoretical studies show that the degree of strain of the vessel wall is indicative of the stresses that can occur in such plaques. If the stresses become too high, a plaque can tear open, so that a life-threatening thrombosis can arise.
[0008] Although for a two-dimensional cross-section, satisfactory measuring results can be obtained, in practice there appears to be a need for a three-dimensional display of the hardness information of the wall, so that the elasticity/hardness of at least one surface part of the vessel wall can be measured. With the present technique, it is practically very difficult to reproducibly analyze a blood vessel in such a manner. Furthermore, on the basis of conventional echographic data it is very hard to localize a suspect spot in a blood vessel. In fact, the performance of a single transverse scan at selected positions in a blood vessel provides insufficient information to enable determination of the presence or absence of plaques in the blood vessel as a whole.
DISCLOSURE OF THE INVENTION
[0009] The invention meets such needs and provides a method with which 3D information about the elasticity and/or hardness of a wall of a body cavity, in particular a blood vessel, can be obtained in a consistent and reproducible manner. In this regard, it is observed that with the present conventional technique the correlation between consecutive images is optimized by positioning the sensor as stably as possible, because movement of the sensor in general has a negative effect on the correlation. The invention is based on the insight that precisely by performing a motion transverse to the measuring plane a sufficient correlation between consecutive images can be maintained to enable detection of hardness and/or elasticity properties.
[0010] Accordingly, the method comprises the following steps of:
receiving signals from the tissue with a sensor for measuring the deformation of the tissue in a measuring plane defined by the sensor, which sensor, during a varying pressure exerted on the tissue, is moved along the tissue in a direction transverse to the measuring plane; identifying strain of the tissue from the resulting signals; and relating the strain to elasticity and/or hardness parameters of the tissue.
[0014] According to the invention, signals are received from, e.g., a vessel wall in a preferably almost continuous motion, consecutive (groups of) frames still having a sufficient correlation to enable distillation of the relevant information. This can be determined by means of a probability function indicating the relation between consecutive images. By controlling the motion (or feeding back feedback position) related to this probability function, an optimum palpogram quality is obtained, which can even be more favorable than in a stationary arrangement.
[0015] The method preferably comprises the step of displaying elasticity and/or hardness parameters of the tissue surface or tissue volume part extending practically parallel to the direction of motion of the sensor, if required, combined with position information of the sensor and/or the tissue. The deformation can be determined with an acoustic or optical sensor detecting echographic or optical data.
[0016] In a further preferred embodiment, signals possessing an optimum overlap are received. An optimum overlap can be determined by means of a probability function displaying the similarity between consecutive signals.
[0017] In the alternative or in addition thereto, at an assumed cyclic pressure change, signals can be received at predetermined time intervals in the period of the motion. In a preferred embodiment, these are signals of a blood vessel wall, the data being received only during a specific time interval of the period of the heartbeat. An advantage thereof is that signals that are not or less suitable for the determination of elasticity and/or hardness information of the tissue need not be stored, as a result of which data storage capacity can be performed to a limited extent, and the data processing can be significantly simplified.
[0018] The invention has a special use in case the tissue is an artery moving through the heartbeat in the longitudinal direction. In that case, the sensor can be moved practically parallel to this direction, so that during at least one detection period, the sensor is in a practically fixed position relative to the tissue. Practice shows that in particular in or near the heart, where relatively strong longitudinal motions of the artery occur, a strongly improved recording of hardness and/or elasticity properties, compared to the conventional recording technique, is obtained in a measuring plane transverse to the vessel wall.
[0019] The invention further relates to an apparatus for using the method according to the invention, comprising:
a sensor movable through a blood vessel or body cavity for recording signals from the tissue; a processor device for collecting and processing signals from the sensor to identify strain of the tissue and to relate the strain to elasticity and/or hardness parameters of a tissue surface or tissue volume part extending practically parallel to the direction of motion of the sensor; and a display device for displaying elasticity and/or hardness parameters of the tissue surface or tissue volume part.
[0023] In a preferred embodiment, the apparatus further comprises a position recording means coupled with the processor device to record sensor positions. The position recording means can display the 3D coordinates of the sensor relative to a fixed reference, e.g., by means of (electromagnetic) bearings, or in a simpler embodiment it may be a relative linear measure from, e.g., the point where a catheter is inserted or from a specific fixed location in a blood vessel.
[0024] In a mechanized use, the apparatus may be provided with an actuator for moving the sensor. Preferably, the actuator has an adjustable speed of motion. Position recording may thereby occur by means of measuring and/or adjusting the speed of motion of the sensor and/or the actuator.
[0025] In a further preferred embodiment, activating means are provided to activate data storage means for recording signals. Further activating means may be provided to activate the actuator. The activating means may be connected with an ECG recording device. In this manner, signals can be received from a blood vessel, the data being received only during a specific time interval of the period of the heartbeat. In the alternative or in addition thereto, the activating means may detect the correlation between consecutive echographic images and activate the data storage means at a the predetermined correlation.
[0026] In another further preferred embodiment, the sensor is arranged in a catheter, which can be inserted into a blood vessel, which sensor can record signals under controlled pullback of the catheter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The invention will further be explained on the basis of the description of the drawings, in which:
[0028] FIG. 1 is a diagrammatic representation of the apparatus according to the invention;
[0029] FIG. 2 a is a 3D palpogram of a phantom with a soft plaque part;
[0030] FIG. 2 b is a longitudinal section of the 3D palpogram of FIG. 2 a, combined with conventional echographic information;
[0031] FIGS. 3 a, 3 b and 3 c are a series of six 3D palpograms of a similar aorta part of a rabbit, obtained in six different measurements; and
[0032] FIG. 4 is a 3D palpogram of a human coronary artery, obtained in vivo.
DETAILED DESCRIPTION OF THE INVENTION
[0033] FIG. 1 is a diagrammatic representation of the apparatus 1 according to the invention. This apparatus comprises a movable catheter 2 provided with an acoustic sensor 3 . A processor 4 is present to collect and process echographic data; the processor 4 is connected with a display device 5 . The processor 4 is further in contact with a position recording means 6 for recording the position of the sensor 3 .
[0034] The catheter 2 can be moved through a blood-vessel 7 , which blood vessel 7 has a vessel wall 8 deformed by the heartbeat. The deformation can be derived by the processor 4 from the echographic data of the catheter 2 and related to elasticity and/or hardness parameters of the wall 8 .
[0035] In explanation, a plaque 9 is shown in the blood vessel 7 . This plaque comprises a fat core 10 closed by a harder cap 11 . The motion of the catheter 2 is controlled by an actuator 12 . The actuator 12 has an adjustable speed of motion, such that the catheter can be moved at a speed of 0.1-2 mm/s. The preferred direction is a so-called pullback direction, i.e. the catheter 2 is inserted until a maximum insertion depth and is then pulled back by the actuator 12 . The actuator can pull the catheter 2 back in a practically continuous motion. The actuator 12 can be activated by the activating means 13 .
[0036] In the alternative, the activating means 13 can be controlled by data from an ECG device 14 , so that a favorable moment of the heartbeat can be selected to perform a measurement. This will be explained below in more detail. During the performance of the measurement, the motion can be interrupted, so that an intermittent pullback motion can be performed. The activating means 13 can also be coupled with a data storage means 15 for storing echographic data. This ensures that the extensive amount of echographic data is received only during a relevant part of the heartbeat, which results in a favorable capacity saving and significantly simplifies the data processing.
[0037] Besides through selection of a relevant part of the heartbeat for the performance of the palpographic measurement, the activating means can be connected, additionally or alternatively, with correlation-detection means 16 detecting the correlation between consecutive echographic images to become active at a predetermined correlation.
[0038] The method according to the invention will be explained below. At a varying pressure as a result of the heartbeat, echographic data are received by the acoustic sensor 3 , while the sensor 3 is moved along the vessel wall 8 . The echographic data can be analyzed by a processor 4 , strain of the vessel wall 8 being identified from the resulting echographic data; and the strain being related to elasticity and/or hardness parameters of the vessel wall 8 . In this manner, it is possible to display elasticity and/or hardness parameters of a tissue surface or tissue volume part extending practically parallel to the direction of motion of the sensor. In a preferred embodiment, in such a display, i.e., a palpogram or an elastogram of the vessel wall, the position information of the sensor and/or the tissue is displayed as well. The motion can be a practically continuous motion; in the alternative, an intermittent motion can be performed. The motion and/or the analysis of echographic data can be controlled, so that the echographic data are received at predetermined time intervals in the period of the heartbeat, at which time interval the motion may be interrupted.
[0039] In the alternative, only those signals possessing an overlap can be received. An optimum overlap can be determined by means of a probability function displaying the similarity between consecutive signals.
[0040] The palpogram of FIG. 2 a has been obtained by scanning a phantom with a soft inclusion, shown in cross-section by the echogram of FIG. 2 b. The phantom has the shape of a hollow tube and is made of polyvinyl alcohol cryogel. The inclusion comprises a harder cap, which may also be present in a naturally formed plaque. The thickness of the cap varies from 2 mm to 800 μm.
[0041] The inclusion thus has mechanical properties corresponding to those of a plaque that may be present in a natural blood vessel.
[0042] The phantom was kept under water and subjected to a pulsatile pressure. A catheter provided with an acoustic converter was moved through the phantom at a speed of 1.0 mm/s. The number of acquired frames was about 30 per second, i.e., an axial displacement of 0.03 mm per image. At a beam width of about 0.6 mm, this proved to be an acceptable amount.
[0043] In the soft part, a strain until 1% was observed. The strain increases with a decreasing thickness of the cap.
[0044] The palpograms of FIGS. 3 a, 3 b and 3 c have been obtained by scanning an artherosclerotic aorta of a New Zealand White rabbit at a pullback speed of 0.5 and 1 mm/s, respectively. In this Figure, FIG. 3 a is a first scan; FIG. 3 b is a second scan obtained after the catheter was positioned again; and FIG. 3 c is a scan obtained some time after, with the catheter again being inserted into the animal.
[0045] The palpograms have been obtained at a speed of motion of the catheter of 1.0 mm/s. In the palpograms, the plaque is always clearly visible as a lighter region.
[0046] In all cases, the following measuring method was used:
[0047] 1. contour detection;
[0048] 2. selection of frames with a minimum mutual motion;
[0049] 3. estimating the displacement of the wall between two frames;
[0050] 4. deriving the strain;
[0051] 5. averaging the strain per angle;
[0052] 6. (color) coding the strain at the contour.
[0053] Of three patients a palpogram was obtained; FIG. 4 shows an example thereof The hatched regions do not represent available measuring values, as a result of the presence of a side branch of the aorta. As appears from the figure, the largest strain occurs in the regions around the side branch (light regions). It turned out that the motion of the catheter was slight enough to determine a reliable palpogram during a heartbeat. The degree of overlap between consecutive frames always remained at least about 70%.
[0054] In an experiment, a palpogram was obtained in which the data were divided into heart cycles, using the R-wave of the ECG signal. Because of the natural motion of the catheter through the varying speed of flow of the blood and the contraction of the heart, the catheter moves deeper into the coronary artery during the diastolic phase. Therefore, measurement is performed during this phase (i.e., a decreasing pressure of the heart and an increasing speed of flow), and the catheter is pulled out against the natural motion. This was done at a speed between 0.5 and 1.0 mm/s, by means of a mechanical actuator (Trakback, JoMed Imaging, Rancho Cordova, Calif., USA).
[0055] It turned out that through this motion the sensor, during the detection period, has a practically fixed position relative to the wall of the artery. It was found that the motion from the measuring plane is minimized, so that the quality of the palpogram is improved.
[0056] Although the invention has been discussed on the basis of the above-mentioned exemplary embodiment, in which the presence of plaques in a blood vessel was checked, it is clear that the invention can also be used when detecting and analyzing other tissues, such as (for cancer research of) the prostate, the esophagus etc. Instead of measuring deformations as a result of a naturally varying pressure, the apparatus can be provided with means for artificially exerting a pressure variation on the tissue.
[0057] Furthermore, all kinds of variations and modifications may be used without departing from the spirit of the invention. Such variations may, e.g., comprise the display of a 3D palpogram as a stack of 2D palpograms; the display of the angle at which measurement is performed; or a combination display of a palpogram and an angiogram.
[0058] Such and other variations are deemed to be within reach and the scope of protection of the appended claims. | A method for generating hardness information of tissue subject to a varying pressure. The method comprises receiving signals from the tissue from a sensor for measuring the deformation of the tissue in a measuring plane defined by the sensor, which sensor, during a varying pressure exerted on the tissue, is moved along the tissue in a direction transverse to the measuring plane; identifying strain of the tissue from the resulting signals; and relating the strain to elasticity and/or hardness parameters of the tissue. The method may comprise the step of displaying elasticity and/or hardness parameters of a tissue surface or tissue volume part extending practically parallel to the direction of motion of the sensor. | 0 |
BACKGROUND
[0001] This disclosure relates to a system and method for a tsunami pod.
[0002] Historically, tsunamis have caused many casualties spanning many countries. Since 2000, there have been two very deadly tsunamis recorded: the 2004 Indian Ocean tsunami estimated to claims 230,000 and 310,000 of lives and the recent 2011 Pacific Ocean tsunami that caused around 20,000 deaths in Japan. A tsunami is a series of massive waves resulting from a large displacement of overlying water, often caused by earthquakes, volcanic eruptions, or underwater landslides.
[0003] Over the years experts have tried to determine when and where a tsunami will occur. There are some early warning systems being used to detect tsunamis in advance. One system uses seismic data to determine a possible threat, and sends a warning to the general public. However, within minutes of detection, a tsunami waves can reach a coastline, giving little time for a local community to prepare and to flee to a higher ground or find suitable shelter. Moreover, running to a higher ground or higher structures can be impossible as not every coastline would have sturdy buildings or mountains nearby. Additionally, the danger of tsunami can last for more than an hour and can even occur a few days following its first hit. Therefore, it is imperative that the locals have enough supply of food, water, and emergency kit (such as flashlights, battery, radio, etc.) that can sustain them for days. However, since tsunami can occur rapidly the affected locals may have no time to prepare essential supplies that can help them conveniently survive during and after a tsunami.
[0004] Tsunami deaths are mainly caused by direct impact of tsunami flow, drowning at the site of the tsunami, being washed away into the ocean, slamming of bodies onto objects, and collisions with floating debris. To help prevent such occurrences a tsunami pod has been developed. Presently an existing tsunami pod exists on the market. A tsunami pod is a pod that one or more person can enter during a tsunami. The tsunami pod prevents water from entering, thereby preserving life inside.
[0005] The spherical shape of existing pods allows for significant movement in all directions. As a consequence the person inside may be jostled significantly, causing sickness and injury. Additionally, existing pods do not provide proper mooring that could prevent a user from being swept out to sea. Further, present systems do not adequately absorb shock and minimize forces exerted on the user or users inside.
[0006] As such, it would be useful to have an improved tsunami pod.
SUMMARY
[0007] An improved tsunami pod is described herein. In one embodiment, the tsunami pod can comprise a body and a ring fender. The body can comprise a top portion, a middle portion, and a base. The base can be wider than the middle portion, and the middle portion can be wider than the top portion. The ring fender can extend out around the base.
[0008] In addition, the disclosure discusses a method for offering protection from a tsunami. Specifically, the method can comprise placing a tsunami pod on a coast. The tsunami pod can comprise a body and a ring fender. The body can comprise a top portion, a middle portion, and a base. The base can be wider than the middle portion, and the middle portion can be wider than the top portion. The ring fender can extend out around the base.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1A illustrates an external view of a tsunami pod comprising a body, a hatch, a crater, and a base.
[0010] FIG. 1B illustrates an embodiment of an opened hatch comprising a ramp and a hand railing.
[0011] FIG. 2A illustrates a cross sectional view of a body comprising an outer shell, a middle layer, and an inner shell.
[0012] FIG. 2B illustrates compartments within a middle layer.
[0013] FIG. 3A illustrates a bottom view of tsunami pod with a connector attached at the bottom center of a base.
[0014] FIG. 3B illustrates a mooring system further comprising a mooring line, and an anchor.
[0015] FIG. 4 illustrates an internal view of a tsunami pod comprising a four-point harness, and a life jacket.
[0016] FIG. 5 illustrates a mid-section view of a tsunami pod showing a set of air intake vent, a set of air outlet vent, a cavity, and a compartment.
[0017] FIG. 6 illustrates a tsunami pod resting on a ground before a tsunami hits.
[0018] FIG. 7 illustrates a tsunami pod floating on water during a tsunami.
DETAILED DESCRIPTION
[0019] Described herein is a system and method for a tsunami sheltering pod. The following description is presented to enable any person skilled in the art to make and use the invention as claimed and is provided in the context of the particular examples discussed below, variations of which will be readily apparent to those skilled in the art. In the interest of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual implementation (as in any development project), design decisions must be made to achieve the designers' specific goals (e.g., compliance with system- and business-related constraints), and that these goals will vary from one implementation to another. It will also be appreciated that such development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the field of the appropriate art having the benefit of this disclosure. Accordingly, the claims appended hereto are not intended to be limited by the disclosed embodiments, but are to be accorded their widest scope consistent with the principles and features disclosed herein.
[0020] FIG. 1A illustrates an external view of a tsunami pod 100 comprising a body 101 , a side hatch 102 , and a top hatch 103 . Tsunami pod 100 can be a mobile structure that can be used as a safe shelter by one or more passenger during a tsunami. Body 101 can have a rounded or polygon form, or combination of round edges and straight edges, which can be the main housing of tsunami pod 100 . In one embodiment, tsunami pod can be substantially octagonal. Moreover, body 101 can serve as a protective shell from the outside environment during a tsunami. Body 101 can comprise a top portion 101 a, a middle portion 101 b, and a bottom portion 101 c. Body 101 can have a narrow perimeter that gradually gets wider from top portion 101 a to bottom portion 101 c. In one embodiment, body 101 can have a conical shape. The form of body 101 can ensure that tsunami pod 100 can be self-up righting during a tsunami. Additionally, top portion 101 a can have more buoyancy while bottom portion 101 c can have more mass to ensure that tsunami pod 100 can maintain lower center of gravity. Since, bottom portion 101 c has more weight this can prevent tsunami pod 100 from being heaved or turned over by the waves. Furthermore, the wide bottom portion 101 c can ensure that tsunami pod 100 can provide an inherent hydrodynamic stability, reducing the constant motion and impact experienced by the user of the tsunami pod 100 . Bottom portion 101 c can be filled or ballasted to help tsunamis pod 100 float and to enhance its stability. Since bottom portion 101 c can be the portion of body 101 that has the widest perimeter and is at the level of the water surface, bottom portion 101 c is the portion of the body most likely to collide with debris and structures. As such, bottom portion 101 c can comprise a ring fender 112 made up of elastic materials such as recycled tires and/or rubbers that scan deflect any debris or blockage before bumping into body 101 . Such characteristic can be used to absorb some of the force from a collision thus, reducing direct impact and preventing damage to body 101 .
[0021] The round or high order polygon shape (ideally five or greater) of body 101 can ensure that tsunami pod 100 does not get stuck and/or trapped between any large floating objects or structures. This shape can also reduce wind loads and water loads during a tsunami.
[0022] Side hatch 102 can be an entrance and/or an exit from tsunami pod 100 . Side hatch 102 can have a watertight design to ensure that no water can pass through side hatch 102 into tsunami pod 100 . Side hatch 102 can be fastened at bottom portion 101 c and opens downward. As such, side hatch 102 can be pulled from the top and drag it towards the ground through a handle 105 . Handle 105 can allow a passenger to easily open and access tsunami pod 100 .
[0023] Top hatch 103 can be an opening at the top of body 101 that can serve as an extra opening in case side hatch 102 is obstructed or in case tsunami pod 100 drifts of to the sea. Furthermore, top hatch 103 can be a safe opening for a passenger when sending distress signals and/or flares. Additionally, aircraft rescuers can have an easier access through top hatch 103 as it provides a fast and safe exit point from above. Top hatch 103 can further comprise a canopy 106 that can serve as a sun screen cover for top hatch 103 . As such, canopy 106 can be installed above top hatch 103 and attached through a fastener such as tow lugs. Top hatch 103 can further comprise of one or more recessed pad-eye 107 . Pad-eye 107 can serve as hand support as a person tries to access and/or escape through top hatch 103 . Pad-eye 107 can be an attachment point used by rescuers for temporarily attaching tsunami pod 100 with rescue transport such as helicopters and ships.
[0024] Further, body 101 can comprise a window 108 placed in middle portion 101 b. Window 108 can be a small sealed orifice made of unbreakable transparent material such as fiber glass, and hard plastics. Window 108 can be impact resistant and made of thick wall glass, which is fully recessed into the walls of body 101 . Furthermore, window 108 can serve as small viewing window that allow passage of light and gives the survivor an option to view the condition or see what's happening outside of the tsunami pod 100 .
[0025] Base 104 can be a platform wherein body 101 rests. In one embodiment base 104 can be made up of heavy materials that can stabilize and ensure that tsunami pod 100 is kept afloat. Base 104 can further connect to a mooring system 109 . Mooring system 109 can comprise of several devices that can be used for keeping tsunami pod 100 floating within the mooring area.
[0026] FIG. 1B illustrates an embodiment of an open side hatch 102 comprising a ramp 110 and a hand railing 111 . In one embodiment, ramp 110 can be a series of recessed portion at the inner surface of side hatch 102 . In such embodiment, ramp 110 can be used as stairs to access tsunami pod 100 . In another embodiment, ramp 110 can be a series of protruding portion at the inner surface of side hatch 102 . Hand rail 111 can be a device that a passenger can grasped on while ascending or descending to or from ramp 110 . During a tsunami, hand rail 111 can provide support and stability to a passenger accessing tsunami pod 100 . In one embodiment, ramp 110 can comprise rubber or other high friction material that can prevent or minimize the risk of a passenger from slipping on ramp 110 .
[0027] FIG. 2A illustrates a cross sectional view of body 101 comprising an outer shell 201 , a middle layer 202 , and an inner shell 203 . Outer shell 201 can be the exterior layer that covers body 101 of tsunami pod 100 . Outer shell 201 can be made of light, durable, waterproof, and thermoplastic materials such as corrugated polypropylene, corrugated high density polyethylene, or polyurethane sheet. Outer shell 201 can be abrasion and tear resistant, therefore reducing possible wearing and damage that can help in prolonging service life of tsunami pod 100 . Moreover, outer shell 201 can be weather resistant that can withstand general weather conditions. Additionally, outer shell 201 can have high dielectric or resistive properties, which ensures that an electric charge does not flow through, thus protecting people inside tsunami pod 100 from electrical accidents. Furthermore, outer shell 201 can be elastic to minimize the load that gets transmitted to middle layer 202 and inner shell 203 . In one embodiment, exterior surface of outer shell 201 can be painted in bright colors such as yellow or orange to make easily visible. As such, rescue vehicles which includes but are not limited to aircrafts, helicopters, and ships can easily see tsunami pod 100 .
[0028] Middle layer 202 can be made up of resilient materials, which can include but are not limited to foam, fiber pouches, or simply air. In any of these embodiments, middle layer can comprise compartments 204 . Middle layer 202 can also be the section that provides the desired buoyancy to tsunami pod 100 . Furthermore, middle layer 202 can be used for sound and/or vibration dampening. These properties can aid in calming and lessening ear strain, headaches, and/or stress experienced by people inside tsunami pod 100 . Middle layer 202 can also dampen shock impulses, which helps in dissipating kinetic energy from wave motions. Moreover, middle layer 202 separates outer shell 201 and inner shell 203 , which can prevent and/or reduce malfunctions and damage from corrupting inner shell 203 .
[0029] Inner shell 203 can be the interior layer of body 101 . Inner shell 203 can be made of light materials that have high resistance to deformation such as steel, aluminum, or fibre-reinforced plastic (FRP). Moreover, inner shell 203 can last longer and requires less maintenance. Further, multiple watertight compartments 204 can be created in nodes wherein outer wall and inner wall are connected that also serves as an additional protection during a collision. Top portion of inner shell 203 can also be installed with LED light fixtures to ensure that enough lighting is provided within tsunami pod 100 .
[0030] FIG. 2B illustrates an close-up view of middle layer 202 that can comprise a plurality of compartments 204 . Outer shell 201 and inner shell 203 can be connected such that they create watertight compartments 204 . Compartments 204 can be within middle layer 202 , which can allow tsunami pod 100 to stay buoyant in the event outer shell is punctured. Compartments 204 can very size from small, as shown in FIG. 2B , to larger compartments, such as entire sides of body 101 .
[0031] FIG. 3A illustrates a bottom view of tsunami pod 100 with a connector 301 attached at the bottom center of base 104 . Connector 301 can be a device that securely fastens tsunami pod 100 with a support structure. To ensure that tsunami pod 100 can move and rotate freely, connector 301 can be a swivel connector such as a bow eye swivel. As such, connector 301 allows tsunami pod to rotate horizontally and within a support structure.
[0032] FIG. 3B illustrates mooring system 110 . Along with connector 301 , mooring system 110 can further comprise a mooring line 302 , and an anchor 303 . Mooring line 302 can be a cable device such as steel wire rope that can be used to connect tsunami pod 100 with anchor 303 . As such, one end of mooring line 302 can be fastened to connector 301 providing tension at base 104 , while the other end can be attached to the ground through anchor 303 . Moreover, length of mooring line 302 can be long enough to provide safety margins and flexible to move above water. Mooring line 302 can also allow tsunami pod 100 to move freely thus loads from impacts can be minimized.
[0033] Anchor 303 can be a device that is used to temporarily affix tsunami pod 100 to the seabed. Tsunami pod 100 can use various type of burying anchor which can include but are not limited to fluke anchor, hinged plow anchor, claw anchor, and/or any conventional maritime anchor. Type of anchor 303 that can be used varies depending on the location of tsunami pod 100 . Such types of anchor 303 can have a compact flat design and can be light weight so it can be easily retrieved and stored when needed. Anchor 303 can be pre-installed at site or optionally could be deployed at will, when required at the time of tsunami. When a current or a wave is encountered during a tsunami, tsunami pod 100 can resist movement accordingly with anchor 303 .
[0034] FIG. 4 illustrates an internal view of tsunami pod 100 comprising a harness 401 , and a life jacket 402 . In one embodiment, harness 401 can be a four-point harness. Harness 401 and life jacket 402 can be installed on the walls of inner shell 203 . In another embodiment, the harness 401 can be installed on the inside base, for the passenger to lie down with their back on the inside floor. Harness 401 can be a safety device used to secure a passenger against harmful movements caused by a collision. Harness 401 can provide a passenger a strap to hold on to and a strap for securing himself within tsunami pod 100 . Life jacket 402 can be visible and readily accessible for a passenger to grab onto in case of emergency.
[0035] FIG. 5 illustrates a mid-section view of tsunami pod 100 showing a set of air intake vent 501 , a set of air outlet vent 502 , a cavity 503 , and a storage 504 . Air intake vent 501 can allow fresh air to flow inside tsunami pod 100 . As such, air intake vent 501 can ensure that enough oxygen or airflow is supplied within tsunami pod 100 . Moreover, air intake vent 501 can help regulate the temperature in tsunami pod 100 . Air outlet vent 502 can prevent air pressure build up in tsunami pod 100 . Air outlet vent 601 and air outlet vent 502 can be installed at top portion 101 a, in diametrically opposite ends with some small height difference to ensure natural circulation of air. Moreover, air outlet vent 501 and air outlet vent 502 does not permit water to flow inside the vent.
[0036] Cavity 503 can be the empty space created within inner shell 203 . Cavity 503 can serve as a passengers sitting area. As such inner shell 203 can comprise of padding 505 . Padding 505 can provide protection and comfort for the passenger of tsunami pod 100 . As such, padding 505 can be made up of light, soft, and/or pillow material such as felt, feathers, fabrics, and/or wool.
[0037] Storage 504 can be a commode within bottom portion 101 c. Storage 504 can further comprise a door 506 . Door 506 can be a movable panel that serves as a barrier device in providing access to storage 504 . Door 506 can employ different closure and/or lock mechanism. For purpose of this disclosure, lock system mentioned herein can use various mechanisms that can allow door 506 to close and/or open storage 504 . In one embodiment, door 506 can use a hinged door mechanism. In such embodiment, a fastener device such as a hinge can enable door 506 to swing closed and/or open. In another embodiment, door 506 can utilize a sliding door mechanism. A track and guide system can be utilized to allow door 506 to slide open. The space within storage 504 can be used for housing of food, water, batteries, medical and/or emergency supplies. Storage 504 can be large enough to stock survival supplies, which can be good for a passenger and can last for at least three days.
[0038] FIG. 6 illustrates a tsunami pod 100 resting on a ground 601 before a tsunami hits. Warning signs and signals such as the water 602 pulling away from the shore leaving a wide expanse of seabed can be a way to detect tsunami minutes before a tsunami hits. This gives enough time for people to get away and run into tsunami pod 100 . As such, tsunami pod 100 can be moored to ground 601 near the owner's vicinity. Thus, when tsunami hits the passengers can easily access tsunami pod 100 . Tsunami pod 100 can be large and comfortable enough to carry a passenger.
[0039] FIG. 7 illustrates a tsunami pod 100 floating on water 602 during a tsunami. Tsunami pod 100 can stay afloat on water 602 and stay safely moored to the ground 601 through mooring line 302 and anchor 303 . Moreover, tsunami pod 100 can be capable of minimizing loads during an earthquake due to tsunami pod 100 light weight structure. Since, tsunami pod 100 floats freely above water 602 impacts on floating debris are minimized. Once the tsunami retreats and the water recedes, tsunami pod 100 can be capable of staying in an upright position and rest on ground 601 .
[0040] Various changes in the details of the illustrated operational methods are possible without departing from the scope of the following claims. Some embodiments may combine the activities described herein as being separate steps. Similarly, one or more of the described steps may be omitted, depending upon the specific operational environment the method is being implemented in. It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” | An improved tsunami pod is described herein. In one embodiment, the tsunami pod can comprise a body and a ring fender. The body can comprise a top portion, a middle portion, and a base. The base can be wider than the middle portion, and the middle portion can be wider than the top portion. The ring fender can extend out around the base. In addition, the disclosure discusses a method for offering protection from a tsunami. Specifically, the method can comprise placing a tsunami pod on a coast. The tsunami pod can comprise a body and a ring fender. The body can comprise a top portion, a middle portion, and a base. The base can be wider than the middle portion, and the middle portion can be wider than the top portion. The ring fender can extend out around the base. | 1 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to molecules which are capable of causing exon skipping and, in particular, relates to molecules which are capable of causing exon skipping in the dystrophin gene.
BACKGROUND OF THE INVENTION
[0002] Duchenne muscular dystrophy (DMD) is a severe X-linked muscle wasting disease, affecting 1:3500 boys. Prognosis is poor: loss of mobility by the age of 12, compromised respiratory and cardiac function by late teens, and probable death by the age of 30. The disease is caused by mutations within the large dystrophin gene, such that the reading frame is disrupted leading to lack of dystrophin protein expression and breakdown of muscle fibre integrity [1]. The dystrophin gene is large, with 79 exons. The most common DMD mutation is genomic deletion of one or more exons, generally centred around hotspots involving exons 44 to 55 and the 5′ end of the gene [2]. Mutations of the dystrophin gene that preserve the reading frame result in the milder, non-life threatening Becker muscular dystrophy (BMD).
[0003] Exon skipping induced by antisense oligoribonucleotides (AOs), generally based on an RNA backbone, is a future hope as a therapy for DMD in which the effects of mutations in the dystrophin gene can be modulated through a process of targeted exon skipping during the splicing process. The splicing process is directed by complex multi-particle machinery that brings adjacent exon-intron junctions in pre-mRNA into close proximity and performs cleavage of phosphodiester bonds at the ends of the introns with their subsequent reformation between exons that are to be spliced together. This complex and highly precise process is mediated by sequence motifs in the pre-mRNA that are relatively short semi-conserved RNA segments to which bind the various nuclear splicing factors that are then involved in the splicing reactions. By changing the way the splicing machinery reads or recognises the motifs involved in pre-mRNA processing, it is possible to create differentially spliced mRNA molecules.
[0004] It has now been recognised that the majority of human genes are alternatively spliced during normal gene expression, although the mechanisms involved have not been identified. Using antisense oligonucleotides, it has been shown that errors and deficiencies in a coded mRNA could be bypassed or removed from the mature gene transcripts. Indeed, by skipping out-of-frame mutations of the dystrophin gene, the reading frame can be restored and a truncated, yet functional, Becker-like dystrophin protein is expressed. Studies in human cells in vitro [3, 4] and in animal models of the disease in vivo [5-9] have proven the principle of exon skipping as a potential therapy for DMD (reviewed in [10]). Initial clinical trials using two different AO chemistries (phosphorodiamidate morpholino oligomer (PMO) and phosphorothioate-linked 2′-β-methyl RNA (2′OMePS)) [11] have recently been performed, with encouraging results. Indisputably impressive restoration of dystrophin expression in the TA muscle of four DMD patients injected with a 2′OMePS AO to exon 51 has been reported by van Deutekom et al. [11].
[0005] However, it should be noted that, relative to 2′OMePS AOs, PMOs have been shown to produce more consistent and sustained exon skipping in the mdx mouse model of DMD [12-14; A. Malerba et al, manuscript submitted], in human muscle explants [15], and in dystrophic canine cells in vitro [16]. Most importantly, PMOs have excellent safety profiles from clinical and pre-clinical data [17].
[0006] The first step to a clinical trial is the choice of the optimal AO target site for skipping of those dystrophin exons most commonly deleted in DMD. In depth analysis of arrays of 2′OMePS AOs have been reported [18, 19], and relationships between skipping bioactivity and AO variables examined.
[0007] One problem associated with the prior art is that the antisense oligonucleotides of the prior art do not produce efficient exon skipping. This means that a certain amount of mRNA produced in the splicing process will contain the out-of-frame mutation which leads to protein expression associated with DMD rather than expression of the truncated, yet functional, Becker-like dystrophin protein associated with mRNA in which certain exons have been skipped.
[0008] Another problem associated with the prior art is that antisense oligonucleotides have not been developed to all of the exons in the dystrophin gene in which mutations occur in DMD.
[0009] An aim of the present invention is to provide molecules which cause efficient exon skipping in selected exons of the dystrophin gene, thus being suitable for use in ameliorating the effects of DMD.
SUMMARY OF THE INVENTION
[0010] The present invention relates to molecules which can bind to pre-mRNA produced from the dystrophin gene and cause a high degree of exon skipping in a particular exon. These molecules can be administered therapeutically.
[0011] The present invention provides a molecule for ameliorating DMD, the molecule comprising at least a 25 base length from a base sequence selected from:
[0000] (SEQ ID NO: 1) a) XGA AAA CGC CGC CAX XXC XCA ACA GAX CXG; (SEQ ID NO: 2) b) CAX AAX GAA AAC GCC GCC AXX XCX CAA CAG; (SEQ ID NO: 3) c) XGX XCA GCX XCX GXX AGC CAC XGA XXA AAX; (SEQ ID NO: 4) d) CAG XXX GCC GCX GCC CAA XGC CAX CCX GGA; (SEQ ID NO: 5) e) XXG CCG CXG CCC AAX GCC AXC CXG GAG XXC; (SEQ ID NO: 6) f) XGC XGC XCX XXX CCA GGX XCA AGX GGG AXA; (SEQ ID NO: 7) g) CXX XXA GXX GCX GCX CXX XXC CAG GXX CAA; (SEQ ID NO: 8) h) CXX XXC XXX XAG XXG CXG CXC XXX XCC AGG; (SEQ ID NO: 9) i) XXA GXX GCX GCX CXX XXC CAG GXX CAA GXG; (SEQ ID NO: 10) j) CXG XXG CCX CCG GXX CXG AAG GXG XXC XXG; (SEQ ID NO: 11) k) CAA CXG XXG CCX CCG GXX CXG AAG GXG XXC; or (SEQ ID NO: 12) l) XXG CCX CCG GXX CXG AAG GXG XXC XXG XAC,
wherein the molecule's base sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in an exon of the dystrophin gene.
[0012] The exon of the dystrophin gene is selected from exons 44, 45, 46 or 53. More specifically, the molecule that causes skipping in exon 44 comprises at least a 25 base length from a base sequence selected from:
[0000] (SEQ ID NO: 1) a) XGA AAA CGC CGC CAX XXC XCA ACA GAX CXG; (SEQ ID NO: 2) b) CAX AAX GAA AAC GCC GCC AXX XCX CAA CAG; or (SEQ ID NO: 3) c) XGX XCA GCX XCX GXX AGC CAC XGA XXA AAX,
wherein the molecule's sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in exon 44 of the dystrophin gene.
[0013] The molecule that causes skipping in exon 45 comprises at least a 25 base length from a base sequence selected from:
[0000] (SEQ ID NO: 4) d) CAG XXX GCC GCX GCC CAA XGC CAX CCX GGA; or (SEQ ID NO: 5) e) XXG CCG CXG CCC AAX GCC AXC CXG GAG XXC,
wherein the molecule's sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in exon 45 of the dystrophin gene.
[0014] The molecule that causes skipping in exon 46 comprises at least a 25 base length from a base sequence selected from:
[0000] (SEQ ID NO: 6) f) XGC XGC XCX XXX CCA GGX XCA AGX GGG AXA; (SEQ ID NO: 7) g) CXX XXA GXX GCX GCX CXX XXC CAG GXX CAA; (SEQ ID NO: 8) h) CXX XXC XXX XAG XXG CXG CXC XXX XCC AGG; or (SEQ ID NO: 9) i) XXA GXX GCX GCX CXX XXC CAG GXX CAA GXG,
wherein the molecule's sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in exon 46 of the dystrophin gene.
[0015] The molecule that causes skipping in exon 53 comprises at least a 25 base length from a base sequence selected from:
[0000] (SEQ ID NO: 10) j) CXG XXG CCX CCG GXX CXG AAG GXG XXC XXG; (SEQ ID NO: 11) k) CAA CXG XXG CCX CCG GXX CXG AAG GXG XXC; or (SEQ ID NO: 12) l) XXG CCX CCG GXX CXG AAG GXG XXC XXG XAC,
wherein the molecule's sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in exon 53 of the dystrophin gene.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows a scheme summarizing the tools used in the design of PMOs to exon 53. (a) Results of ESEfinder analysis, showing the location and values above threshold for SF2/ASF, SF2/ASF (BRCA1), SC35, SRp40 and SRp55, shown as grey and black bars, as indicated in the legend above. (b) Output of PESX analysis, showing the location of exonic splicing enhancers as solid lines, and exonic splicing silencer as a dashed line. (c) Rescue ESE analysis for exon 53, showing predicted ESEs by lines, and where they overlap, by a ladder of lines. (d) AccessMapper analysis of in vitro hybridization. Synthetic pre-mRNA containing exon 53 and surrounding introns was subjected to a hybridization screen against a random hexamer oligonucleotide array, as described in Materials and Methods. Areas of hybridization, suggestive of areas of open conformation, are indicated by peaks on the graph. (e) The position of the target sites of two 2′OMePS AOs studied previously [18] are shown for comparison. (f) The location of the target sites for all the 25mer and 30mer PMOs to exon 53 used in this study are indicated by lines, and numbered according to the scheme used in Table 1, except for exclusion of the prefix “h53”;
[0017] FIG. 2 shows a comparison of active (effective) and inactive (ineffective) PMOs. RT-PCR analysis of mRNA from normal human skeletal muscle cells treated with PMOs to exon 53 demonstrates a wide variation in the efficiency of exon skipping. Over 75% exon skipping is seen with h53A30/2 (lane 5) and h53A30/3 (lane 6). h53A30/1 (lane 4) produced around 50% skipping, while the 25-mer h53A1 (lane 3) produced just over 10% skipping. In contrast, h53C1 (lane 2) was completely inactive. Lane 1 contains a negative control in which cells were treated with lipofectin but no PMO.
[0018] FIG. 3 shows an Mfold secondary structure prediction for exon 53 of the human dystrophin gene. MFOLD analysis [25] was performed using exon 53 plus 50 nt of the upstream and downstream introns, and with a maximum base-pairing distance of 100 nt. The intron and exon boundaries are indicated, as are the positions of the target sites of the bioactive PMO h53A30/2 (87.2% skip) and an inactive PMO (h53B2). Examples of open and closed RNA secondary structure are arrowed.
[0019] FIG. 4 shows boxplots of parameters significant to strong PMO bioactivity. Comparisons were made between inactive PMOs and those inducing skipping at levels in excess of 75%. Boxplots are shown for parameters which are significant on a Mann-Whitney rank sum test: PMO to target binding energy, distance of the target site from the splice acceptor site, the percentage overlap with areas of open conformation, as predicted by MFOLD software, and the percentage overlap of the target site with the strongest area accessible to binding, as revealed by hexamer hybridization array analysis. Degrees of significance are indicated by asterisks. *: p<0.05; **: p<0.01; ***: p<0.001.
[0020] FIG. 5 shows boxplots of parameters significantly different between bioactive (effective) and inactive (ineffective) PMOs. Comparisons were made between PMOs determined as bioactive (those that induced skipping at greater than 5%) and those that were not. Boxplots are shown for parameters which are significant from a Mann-Whitney rank sum test: PMO to target binding energy, distance of the target site from the splice acceptor site, the score over threshold for a predicted binding site for the SR protein SF2/ASF, and the percentage overlap of the target site with the strongest area accessible to binding, as revealed by hexamer hybridization array analysis. Degrees of significance are indicated by asterisks. *: p<0.05; **: p<0.01; ***: p<0.001.
[0021] FIG. 6 shows a comparison of bioactivity of PMOs targeted to exon 53 in normal hSkMCs. Myoblasts were transfected with each of the 25mer (panel a) and 30mer (panel b) PMOs indicated at 500 nM using lipofectin (1:4). RNA was harvested after 24 hours and subjected to nested RT-PCR and products visualised by agarose gel electrophoresis.
[0022] FIG. 7 shows low dose efficacy and timecourse of skipping of the most bioactive PMOs in normal hSkMCs. (a) hSkMC myoblasts were transfected with the PMOs indicated over a concentration range of 25 nM to 100 nM using lipofectin (1:4). RNA was harvested after 24 hours and subjected to nested RT-PCR, and products visualised by agarose gel electrophoresis. (b) hSkMC myoblasts were transfected with 100 nM and 500 nM concentrations of PMO-G (+30+59) using lipofectin. RNA was harvested at the timepoints indicated following transfection and subjected to nested RT-PCR, and products visualised by agarose gel electrophoresis. Skipped (248 bp) and unskipped (460 bp) products are shown schematically.
[0023] FIG. 8 shows blind comparison of 13 PMO oligonucleotide sequences to skip human exon 53. Myoblasts derived from a DMD patient carrying a deletion of dystrophin exons 45-52 were transfected at 300 nM in duplicate with each of the PMOs by nucleofection. RNA was harvested 3 days following transfection, and amplified by nested RT-PCR. (a) Bars indicate the percentage of exon skipping achieved for each PMO, derived from Image J analysis of the electropherogram of the agarose gel (b). Skipped (477 bp) and unskipped (689 bp) products are shown schematically.
[0024] FIG. 9 shows the dose-response of the six best-performing PMOs. (a) Myoblasts derived from a DMD patient carrying a deletion of dystrophin exons 45-52 were transfected with the six best-performing PMOs by nucleofection, at doses ranging from 25 nM to 400 nM. RT-PCR products derived from RNA isolated from cells 3 days post-transfection were separated by agarose gel electrophoresis. (b) The percentage of exon skipping observed is expressed for each concentration of each PMO as a comparison of the percentage OD of skipped and unskipped band, as measured using Image J.
[0025] FIG. 10 shows persistence of dystrophin expression in DMD cells following PMO treatment. (a) Myoblasts derived from a DMD patient carrying a deletion of dystrophin exons 45-52 were transfected by nucleofection at 300 nM with each of the six best-performing PMOs, and were cultured for 1 to 10 days before extracting RNA. The percentage of exon skipping was compared using the percentage OD of skipped and unskipped bands, measured using Image J analysis of the agarose gel of the nested RT-PCR products shown in (b). The experiment was repeated, but this time using the two best-performing PMOs from the previous analysis, and continuing the cultures for 21 days post-transfection (c and d). (e) Western blot analysis was performed on total protein extracts from del 45-52 DMD cells 7 days after transfection with the six best PMOs (300 nM). Blots were probed with antibodies to dystrophin, to dysferlin as a muscle-specific loading control, and protogold for total protein loading control. CHQ5B myoblasts, after 7 days of differentiation were used as a positive control for dystrophin protein (normal).
[0026] FIG. 11 shows a comparison of most active PMOs in hDMD mice. PMOs were injected in a blind experiment into the gastrocnemius muscle of hDMD mice. RT-PCR analysis of RNA harvested from isolated muscle (L=left, R=right) was performed and products visualised by agarose gel electrophoresis. Quantification of PCR products was performed using a DNA LabChip.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Without being restricted to any particular theory, it is thought by the inventors that the binding of the molecules to the dystrophin pre-mRNA interacts with or interferes with the binding of SR proteins to the exon of interest. SR proteins are involved in the slicing process of adjacent exons. Therefore, it is thought that interacting or interfering with the binding of the SR proteins interferes with the splicing machinery resulting in exon skipping.
[0028] The base “X” in the above base sequences is defined as being thymine (T) or uracil (U). The presence of either base in the sequence will still allow the molecule to bind to the pre-mRNA of the dystrophin gene as it is a complementary sequence. Therefore, the presence of either base in the molecule will cause exon skipping. The base sequence of the molecule may contain all thymines, all uracils or a combination of the two. One factor that can determine whether X is T or U is the chemistry used to produce the molecule. For example, if the molecule is a phosphorodiamidate morpholino oligonucleotide (PMO), X will be T as this base is used when producing PMOs. Alternatively, if the molecule is a phosphorothioate-linked 2′-O-methyl oligonucleotide (2′OMePS), X will be U as this base is used when producing 2′OMePSs. Preferably, the base “X” is only thymine (T).
[0029] The advantage provided by the molecule is that it causes a high level of exon skipping. Preferably, the molecule causes an exon skipping rate of at least 50%, more preferably, at least 60%, even more preferably, at least 70%, more preferably still, at least 76%, more preferably, at least 80%, even more preferably, at least 85%, more preferably still, at least 90%, and most preferably, at least 95%.
[0030] The molecule can be any type of molecule as long as it has the selected base sequence and can bind to a target site of the dystrophin pre-mRNA to cause exon skipping. For example, the molecule can be an oligodeoxyribonucleotide, an oligoribonucleotide, a phosphorodiamidate morpholino oligonucleotide (PMO) or a phosphorothioate-linked 2′-O-methyl oligonucleotide (2′OMePS). Preferably, the oligonucleotide is a PMO. The advantage of a PMO is that it has excellent safety profiles and appears to have longer lasting effects in vivo compared to 2′OMePS oligonucleotides. Preferably, the molecule is isolated so that it is free from other compounds or contaminants.
[0031] The base sequence of the molecule can vary from the selected sequence at up to two base positions. If the base sequence does vary at two positions, the molecule will still be able to bind to the dystrophin pre-mRNA to cause exon skipping. Preferably, the base sequence of the molecule varies from the selected sequence at one base position and, more preferably, the base sequence does not vary from the selected sequence. The less that the base sequence of the molecule varies from the selected sequence, the more efficiently it binds to the specific exon region in order to cause exon skipping.
[0032] The molecule is at least 25 bases in length. Preferably, the molecule is at least 28 bases in length. Preferably, the molecule is no more than 35 bases in length and, more preferably, no more than 32 bases in length. Preferably, the molecule is between 25 and 35 bases in length, more preferably, the molecule is between 28 and 32 bases in length, even more preferably, the molecule is between 29 and 31 bases in length, and most preferably, the molecule is 30 bases in length. It has been found that a molecule which is 30 bases in length causes efficient exon skipping. If the molecule is longer than 35 bases in length, the specificity of the binding to the specific exon region is reduced. If the molecule is less than 25 bases in length, the exon skipping efficiency is reduced.
[0033] The molecule may be conjugated to or complexed with various entities. For example, the molecule may be conjugated to or complexed with a targeting protein in order to target the molecule to muscle tissue. Alternatively, the molecule may be complexed with or conjugated to a drug or another compound for treating DMD. If the molecule is conjugated to an entity, it may be conjugated directly or via a linker. In one embodiment, a plurality of molecules directed to exon skipping in different exons may be conjugated to or complexed with a single entity. Alternatively, a plurality of molecules directed to exon skipping in the same exon may be conjugated to or complexed with a single entity. For example, an arginine-rich cell penetrating peptide (CPP) can be conjugated to or complexed with the molecule. In particular, (R-Ahx-R)(4)AhxB can be used, where Ahx is 6-aminohexanoic acid and B is beta-alanine [35], or alternatively (RXRRBR)2XB can be used [36]. These entities have been complexed to known dystrophin exon-skipping molecules which have shown sustained skipping of dystrophin exons in vitro and in vivo.
[0034] In another aspect, the present invention provides a vector for ameliorating DMD, the vector encoding a molecule of the invention, wherein expression of the vector in a human cell causes the molecule to be expressed. For example, it is possible to express antisense sequences in the form of a gene, which can thus be delivered on a vector. One way to do this would be to modify the sequence of a U7 snRNA gene to include an antisense sequence according to the invention. The U7 gene, complete with its own promoter sequences, can be delivered on an adeno-associated virus (AAV) vector, to induce bodywide exon skipping. Similar methods to achieve exon skipping, by using a vector encoding a molecule of the invention, would be apparent to one skilled in the art.
[0035] The present invention also provides a pharmaceutical composition for ameliorating DMD, the composition comprising a molecule as described above or a vector as described above and any pharmaceutically acceptable carrier, adjuvant or vehicle. Pharmaceutical compositions of this invention comprise any molecule of the present invention, and pharmaceutically acceptable salts, esters, salts of such esters, or any other compound which, upon administration to a human, is capable of providing (directly or indirectly) the biologically active molecule thereof, with any pharmaceutically acceptable carrier, adjuvant or vehicle. Pharmaceutically acceptable carriers, adjuvants and vehicles that may be used in the pharmaceutical compositions of this invention include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat.
[0036] The pharmaceutical compositions of this invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally, intradermally or via an implanted reservoir. Oral administration or administration by injection is preferred. The pharmaceutical compositions of this invention may contain any conventional non-toxic pharmaceutically-acceptable carriers, adjuvants or vehicles. The term parenteral as used herein includes subcutaneous, intracutaneous, intravenous, intramuscular, intra-articular, intrasynovial, intrasternal, intrathecal, intralesional and intracranial injection or infusion techniques. Preferably, the route of administration is by injection, more preferably, the route of administration is intramuscular, intravenous or subcutaneous injection and most preferably, the route of administration is intravenous or subcutaneous injection.
[0037] The pharmaceutical compositions may be in the form of a sterile injectable preparation, for example, as a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to techniques known in the art using suitable dispersing or wetting agents (such as, for example, Tween 80) and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are mannitol, water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono- or diglycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions may also contain a long-chain alcohol diluent, dispersant or similar alcohol.
[0038] The pharmaceutical compositions of this invention may be orally administered in any orally acceptable dosage form including, but not limited to, capsules, tablets, and aqueous suspensions and solutions. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are administered orally, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavouring and/or colouring agents may be added.
[0039] The pharmaceutical compositions of this invention may also be administered in the form of suppositories for rectal administration. These compositions can be prepared by mixing a compound of this invention with a suitable non-irritating excipient which is solid at room temperature but liquid at the rectal temperature and therefore will melt in the rectum to release the active components. Such materials include, but are not limited to, cocoa butter, beeswax and polyethylene glycols.
[0040] Topical administration of the pharmaceutical compositions of this invention is especially useful when the desired treatment involves areas or organs readily accessible by topical application. For application topically to the skin, the pharmaceutical composition should be formulated with a suitable ointment containing the active components suspended or dissolved in a carrier. Carriers for topical administration of the compounds of this invention include, but are not limited to, mineral oil, liquid petroleum, white petroleum, propylene glycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water. Alternatively, the pharmaceutical composition can be formulated with a suitable lotion or cream containing the active compound suspended or dissolved in a carrier. Suitable carriers include, but are not limited to, mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. The pharmaceutical compositions of this invention may also be topically applied to the lower intestinal tract by rectal suppository formulation or in a suitable enema formulation. Topically-transdermal patches are also included in this invention.
[0041] The pharmaceutical compositions of this invention may be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and may be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other solubilizing or dispersing agents known in the art.
[0042] In one embodiment, the pharmaceutical composition may comprise a plurality of molecules of the invention, each molecule directed to exon skipping in a different exon. Alternatively, the pharmaceutical composition may comprise a plurality of molecules of the invention, each molecule directed to exon skipping in the same exon.
[0043] In another embodiment, the pharmaceutical composition may comprise a plurality of vectors of the invention, each vector encoding a molecule directed to exon skipping in a different exon. Alternatively, the pharmaceutical composition may comprise a plurality of vectors of the invention, each vector encoding a molecule directed to exon skipping in the same exon.
[0044] In yet another embodiment, the pharmaceutical composition may comprise a molecule and a vector, wherein the molecule and the molecule encoded by the vector are directed to exon skipping in the same or different exons.
[0045] The present invention also provides a molecule of the invention for use in therapy.
[0046] Further, the present invention provides a molecule of the invention for use in the amelioration of DMD.
[0047] The molecules of the present invention cause exon skipping in the dystrophin pre-mRNA. This causes a truncated but functional dystrophin protein to be expressed which results in a syndrome similar to Becker muscular dystrophy (BMD). Therefore, the symptoms of DMD will not be completely treated but will be ameliorated so that they are potentially no longer life threatening.
[0048] The present invention also provides a method of ameliorating DMD in a human patient, the method comprising administering a therapeutically effective amount of the molecule of the invention to the patient.
[0049] The particular molecule that is administered to the patient will depend on the location of the mutation or mutations present in the dystrophin gene of the patient. The majority of patients have deletions of one or more exons of the dystrophin gene. For example, if a patient is missing exon 44, the process of joining exon 43 to exon 45 will destroy the protein, thus causing DMD. If exon 45 is skipped using a molecule of the invention, the joining of exon 43 to exon 46 will restore the protein. Similarly, a patient with a deletion of exon 45 can be treated with a molecule to skip either exon 44 or exon 46. Further, a patient with a deletion of exons 45 to 52 inclusive (a large portion of the gene), would respond to skipping of exon 53.
[0050] In another aspect, the invention provides a kit for the amelioration of DMD in a patient, the kit comprising a molecule of the invention and instructions for its use. In one embodiment, the kit may contain a plurality of molecules for use in causing exon skipping in the same exon or a plurality of exons.
EXAMPLES
Example 1
[0051] Here, the first detailed study of the role that AO target site variables have on the efficacy of PMOs to induce skipping is reported. The results reported here should have an impact on the initial planning and design of AOs for future potential clinical trials.
Materials and Methods
Hybridization Analyses
[0052] Templates for the production of synthetic pre-mRNAs for exons 44, 45, 46, 51, and 53 of the human dystrophin gene (DMD gene) were generated by PCR amplification from genomic clones of the exons, together with approximately 500 nt of upstream and downstream introns. PCR primers incorporated T7 RNA polymerase promoter sequences, such that pre-mRNAs could be produced by in vitro transcription. Pre-mRNAs were then subjected to a hybridization screen against a spotted array of all 4096 possible hexanucleotide sequences (Access Array 4000; Nyrion Ltd, Edinburgh UK). Binding of the pre-mRNA to specific spots on the array was detected by reverse transcriptase-mediated incorporation of biotinylated nucleotides by primer extension, followed by fluorescent labelling. Scanning of the arrays followed by software analysis enabled sequences within the exons that were accessible to binding to the hexamer array to be identified. Using a hybridization assay, binding accessibility of each exons were analysed and hybridization peak identified by AccessMapper software (Nyrion Ltd) (see FIG. 1 d ).
AO Design
[0053] Overlapping AOs were designed to exons 44, 45, 46, 51, and 53 of the human DMD gene using the following information: putative SR protein binding domains as predicted by ESEfinder [20, 21], Rescue ESE [24] and PESX [22, 23] analyses of exon sequence; sequences accessible to binding as determined by hybridization analyses (Nyrion); previously published work [18, 19].
[0054] All AOs were synthesized as phosphorodiamidate morpholino oligos (PMOs) by Gene Tools LLC (Philomath Oreg., USA). To facilitate transfection of these uncharged oligonucleotides into cultured cells, the PMOs were hybridized to phosphorothioate-capped oligodeoxynucleotide leashes, as described by Gebski et al., [12], and stored at 4° C.
[0055] The sequences of some of these PMOs were as follows:
[0000]
(SEQ ID NO: 13)
H44A30/1 -
TGA AAA CGC CGC CAT TTC TCA ACA GAT CTG;
(SEQ ID NO: 14)
H44A30/2 -
CAT AAT GAA AAC GCC GCC ATT TCT CAA CAG;
(SEQ ID NO: 15)
H44AB30/2 -
TGT TCA GCT TCT GTT AGC CAC TGA TTA AAT;
(SEQ ID NO: 16)
H45A30/2 -
CAG TTT GCC GCT GCC CAA TGC CAT CCT GGA;
(SEQ ID NO: 17)
H45A30/1 -
TTG CCG CTG CCC AAT GCC ATC CTG GAG TTC;
(SEQ ID NO: 18)
H46A30/2 -
TGC TGC TCT TTT CCA GGT TCA AGT GGG ATA;
(SEQ ID NO: 19)
H46A30/4 -
CTT TTA GTT GCT GCT CTT TTC CAG GTT CAA;
(SEQ ID NO: 20)
H46A30/5 -
CTT TTC TTT TAG TTG CTG CTC TTT TCC AGG;
(SEQ ID NO: 21)
H46A30/3 -
TTA GTT GCT GCT CTT TTC CAG GTT CAA GTG;
(SEQ ID NO: 22)
H53A30/2 -
CTG TTG CCT CCG GTT CTG AAG GTG TTC TTG;
(SEQ ID NO: 23)
H53A30/3 -
CAA CTG TTG CCT CCG GTT CTG AAG GTG TTC;
(SEQ ID NO: 24)
H53A30/1 -
TTG CCT CCG GTT CTG AAG GTG TTC TTG TAC.
Cell Culture and AO Transfection
[0056] Normal human primary skeletal muscle cells (TCS Cellworks, Buckingham, UK) were seeded in 6-well plates coated with 0.1 mg/ml ECM Gel (Sigma-Aldrich, Poole, UK), and grown in supplemented muscle cell growth medium (Promocell, Heidelberg, Germany). Cultures were switched to supplemented muscle cell differentiation medium (Promocell) when myoblasts fused to form visible myotubes (elongated cells containing multiple nuclei and myofibrils). Transfection of PMOs was then performed using the transfection reagent Lipofectin (Invitrogen, Paisley, UK) at a ratio of 4 μl of Lipofectin per μg of PMO (with a range of PMO concentrations tested from 50 to 500 nM, equivalent to approximately 0.5 to 5 μg) for 4 hrs, according to the manufacturer's instructions. All transfections were performed in triplicate in at least two different experiments.
RNA Isolation and Reverse Transcriptase-Polymerase Chain Reaction Analysis
[0057] Typically 24 h after transfection, RNA was extracted from the cells using the QIAshredder/RNeasy system (Qiagen, Crawley, UK) and ˜200 ng RNA subjected to RT-PCR with DMD exon-specific primers using the GeneScript kit (Genesys, Camberley, UK). From this 20 cycle reaction, an aliquot was used as a template for a second nested PCR consisting of 25 cycles. PCR products were analysed on 1.5% agarose gels in Tris-borate/EDTA buffer. Skipping efficiencies were determined by quantification of the PCR products by densitometry using GeneTools software (Syngene, Cambridge, UK).
Statistical Analysis
[0058] The non-parametric Mann-Whitney rank sum test was used to identify whether parameters for effective PMOs were significantly different to those for ineffective PMOs. Where data was calculated to fit a normal distribution, the more powerful two-tailed Student's t-test was performed instead. Correlations were generated using the Spearman rank-order test. To determine the strength of the combined significant parameters/design tools to design effective PMOs, linear discriminant analysis was used [34], with the Ida function from the MASS package, using “effective” or “ineffective” as the two prior probabilities. The Ida function produces posterior probabilities for the two classes (effective and ineffective) for each PMO by leave-one-out classification.
Results
PMO Design and Analysis of Bioactivity
[0059] A unique set of 66 PMOs has been designed to target exons 44, 45, 46, 51, and 53 of the human gene for dystrophin. The design process for exon 53 is depicted in FIG. 1 , and has also been performed for the other four exons (data not shown). The exon sequence was analysed for the presence of exonic splicing enhancers (ESE) and exonic splicing suppressors or silencers (ESS) and the outputs aligned for the three available algorithms, ESEfinder ( FIG. 1 a ) [20, 21], PESX ( FIG. 1 b ) [22, 23], and Rescue ESE ( FIG. 1 c ) [24]. Hybridization array analysis was also performed for each exon in vitro, as described in Materials and Methods. The peaks shown in FIG. 1 d indicate areas of the exon that are in a conformation able to hybridize to the array, and which may consequently prove more accessible to antisense AOs. The coincidence of ESEs, as predicted by two or more algorithms, and hybridization peaks determined experimentally, was used to design arrays of 25mer and, subsequently, 30mer PMOs, the positions of which are shown in FIG. 1 f . The binding sites for 2′OMePS AOs described previously [18] are shown for comparison ( FIG. 1 e ).
[0060] Each PMO was tested in primary cultures of human skeletal muscle, in triplicate, in at least two experiments, and over a range of concentrations from 50 nM to 500 nM. Their bioactivity was determined by RT-PCR analysis, which showed a wide variation in the level of exon skipping induced ( FIG. 2 , and data not shown), ranging from 0% for h53C1 ( FIG. 1 f and FIG. 2 , lane 2) to 80% for h53A30/3 ( FIG. 1 f and FIG. 2 , lane 6). Sequencing of the PCR products verified accurate skipping of the targeted exon (data not shown). The activity of each PMO at the stated optimal concentration is summarized in Table 1. Bioactivity is expressed as a percentage of the skipped amplicon relative to total PCR product, as assessed by densitometry. Specific, consistent and sustained exon skipping was evident for 44 of the 66 PMOs tested.
In Silico Analysis of PMOs
[0061] We then performed a retrospective in silico analysis of the characteristics of all 66 PMOs tested in this study, with respect to PMO length, the distance of the PMO target site from the splice donor and acceptor sites, PMO-to-target binding energy and PMO-to-PMO binding energy, as calculated using RNAstructure2.2 software for the equivalent RNA-RNA interaction, and percentage GC content of the PMO, the results of which are summarized in Table 1. Also shown in Table 1 is the percentage overlap of each PMO target site with sequences shown to be accessible to binding, as determined experimentally by the hexamer hybridization array analysis. The relationship of PMO target site and RNA secondary structure was also examined using the program MFOLD [25] ( FIG. 3 and data not shown), with the percentage overlap of PMO target site with sequence predicted to be in open conformation by MFOLD analysis given in Table 1. ESEfinder and SSF (http://www.umd.be/SSF/) software analysis of exon sequences revealed the positions of putative SR protein binding motifs (SF2/ASF (by two algorithms), SC35, SRp40, SRp55, Tra2β and 9G8). The highest score over threshold for each SR protein is given for each PMO in the columns on the right of Table 1. Also shown is the degree of overlap of each PMO target site with the ESE and ESS regions predicted by Rescue ESE and PESX.
Statistical Analysis of Design Parameters in Relation to PMO Bioactivity
[0062] For this statistical analysis, bioactive PMOs are considered to be those which produce over 5% skipping, while those that produce less than 5% skipping are considered inactive. For each of the parameters listed in Table 1, comparison was made between bioactive and inactive PMOs using the non-parametric Mann-Whitney rank sum test, or, when it was statistically valid to do so, the parametric Student's t-test (two-tailed). The significant parameters are listed in Table 2. Considering the data as a whole, the variable which showed the highest significance to PMO bioactivity was the binding energy of the PMO to the exon (p=0.001); the most bioactive exons are predicted to bind better to their target sites. Those PMOs that overlap with peaks identified by the experimental hybridization array analysis are not significantly more active than those that do not (p=0.056), but when only the strongest peak for each exon is considered, this parameter becomes highly significant (p=0.003). Distance of the PMO target site to the splice acceptor site of the exon was also highly significant (p=0.004), with PMOs whose target site were closer to the acceptor site being more active. PMOs whose target sites showed coincidence with binding motifs for the SR protein SF2/ASF (as defined by the BRCA1 algorithm of Smith et al. [21]) produced significantly greater skipping (p=0.026). PMO length is also a significant parameter (p=0.017), with longer PMOs being more effective at inducing skipping. Boxplots of the significant variables identified here are shown in FIG. 5 . None of the other variables considered in this study were shown to have any significance to AO bioactivity.
[0063] To ascertain which parameters/design tools are the most powerful, we also used the Mann-Whitney rank sum test to compare the most active PMOs (i.e. those that induce greater than 75% skipping of the target exon) to those that were inactive (i.e. those that produce less than 5% skipping). Boxplots of the significant variables for this comparison are shown in FIG. 4 . There is strong significance of overlap of the PMO target site with the strongest hybridization peak for each exon (p=0.002); more of the most bioactive PMOs had their target sites coincident with sequences accessible to binding than those that were inactive. This is reinforced by the observation that the target sites of PMOs that produced over 75% skipping significantly overlapped more RNA that was in open conformation, relative to inactive PMOs (p=0.025). Stronger binding between the PMO and its target exon, PMO length, and proximity of the target to the acceptor site are also significant parameters when comparing the most and least effective reagents. Spearman's rank order correlation was used to establish potential relationships between design parameters and skipping bioactivity using the entire set of PMOs. This shows a strong correlation between skipping bioactivity and PMO-target binding energy (r s =−0.618, p=0), percentage open conformation (r s =0.275, p=0.0259), PMO length (r s =0.545, p=0), distance from the splice acceptor site (r s =−0.421, p=0), percentage overlap with the strongest hybridization peak (r s =0.46, p=0), and overlap with an ESS sequence, as predicted by PESX (r s =0.261, p=0.0348).
Linear Discriminant Analysis
[0064] This analysis was performed on all possible combinations of length, overlap with the SF2/ASF (BRCA1) motif, percentage overlap with areas of open conformation, percentage overlap with hybridization peak and PMO-target binding energy, i.e. PMO parameters and design tools that showed significance or borderline significance. Using length, SF2/ASF (BRCA1) motif and hybridization peak data, nine of the inactive PMOs were classified as bioactive and four bioactive PMOs were classified as inactive (Table 3). These four misclassified PMOs were 25mers to exon 46, three of which have borderline bioactivity, i.e. produce just 10% skipping, while the fourth produces about 20% skipping. Taken overall, this equates to 80% of the PMOs being predicted correctly when assessed according to their length, SF2/ASF (BRCA1) overlap and hybridization peak overlap. This would suggest that these parameters have the potential to be effective design tools, with four out of every five PMOs designed to have these three properties likely to be bioactive. In line with this, there was a distinct trend for PMOs being correctly assigned as bioactive with increased skipping bioactivity (see Table 3). Indeed, the PMOs with greatest bioactivity were all 30mers (10/10), bound to their target with a high binding energy of below −43.0 kD (9/10), overlapped by over 50% with areas of open conformation (7/10), overlapped with SF2/ASF (BRCA1) peak (8/10), and overlapped with a hybridization peak (7/10).
Discussion
[0065] Clinical studies using AOs to skip exon 51 to correct DMD deletions are progressing well [11; F. Muntoni, Principal Investigator of MDEX Consortium, personal communication]. However since the mutations that cause DMD are so diverse, skipping of exon 51 would have the potential to treat just 24.6% of DMD patients on the Leiden DMD database [26]. It is therefore imperative that pre-clinical optimization of AO target sequence and chemistry is continually studied and improved. This study has examined the significance of design parameters for PMO-induced skipping of exons 44, 45, 46, 51, and 53, which would have the potential to treat, respectively, 11.5%, 15.8%, 8.4%, 24.6% and 13.5% of DMD patients in the Leiden database [26; A. Aartsma-Rus, personal communication].
[0066] Specific skipping was observed for the five DMD exons studied here, with two-thirds of the PMOs tested being bioactive. This proportion of bioactive AOs within a cohort has been reported previously [18, 19], but we have induced high-level (i.e. greater than 75%) skipping in four of the five exons tested, some of which are achievable at relatively low doses of oligomer. The exception is exon 51, published previously [4], achieving a maximal skipping of 26%. The work of Wilton et al [19] demonstrated that only exons 51 and 53 can be skipped with high efficiency (>30% by their definition), and that exons 44, 45 and 46 are less “skippable” (less than 30% skipping). Furthermore, Aartsma-Rus et al [18] showed oligomers capable of high-level skipping (greater than a mere 25%) for only exons 44, 46 and 51.
[0067] We provide here direct evidence that AO bioactivity shows a significant association with accessibility of its target site to binding. This is the first study to assess sequences practically within the pre-mRNA that are accessible to binding and then use them as an aid to AO design. The data we show underline the value of the hybridization analysis in determining what are likely to be the most bioactive oligomers (i.e. those that produce greater than 75% skipping). As an example, if we look at the data for oligomers developed for exon 45 [18], we see that there is only one moderately effective (5-25%) reagent for this otherwise unskippable exon. This oligomer is the only one of the six tested that overlaps with the strongest peak in our hybridization analysis. The partial nature of this overlap, combined with the short length of the oligomer, is likely to contribute to its relative weakness compared to the PMOs we have developed here. In general, the 2′OMePS AOs displaying the highest bioactivity in the work of Aartsma-Rus et al. [18] and Wilton et al. [19], show some degree of overlap with the hybridization peaks that we have defined here for exons 45, 46 and 53.
[0068] Ease of skipping of certain DMD exons has been seen elsewhere [18] and may be related to other factors affecting splicing, including strength of splice donor and acceptor sites and branchpoint, and the size of upstream and downstream introns, which may affect the order in which exons are spliced together. There is the potential of using a cocktail of AOs to induce greater skipping of the more difficult to skip exons [27, 28].
[0069] Accessibility of the AO to its target site depends directly on the secondary structure of the pre-mRNA, which has a major role in determining AO bioactivity in cells. A study in which the structure around an AO target site was changed revealed that AOs were unable to invade very stable stem-loop structures and their antisense activity was inhibited, but generally showed good activity when impeded by little local structure [29]. Overlap of PMO target sites with open conformations in the folded RNA showed a weak association with PMO bioactivity, which was more obvious when only the stronger PMOs were considered in the statistical analysis. It is also possible that there is selective pressure for SR binding sites to be located preferentially on these open secondary structures. The presumption is that binding of bioactive PMOs to their target sites sterically block the binding of important factors involved in RNA processing, resulting in exon skipping.
[0070] One of the PMO parameters with high significance was length; 30mer PMOs were far superior to their 25mer counterparts. The influence of 2′OMePS AO length on bioactivity has been reported elsewhere [30] and such an observation for PMO-induced skipping of exon 51 has been reported previously by us [4]. The more persistent action of longer PMOs would have important cost and dose implications in the choice of AO for clinical trials. Longer AOs are likely to sterically block more of the regions that interact with the splicing machinery, but in general terms, the energy of binding of the longer PMO to its target would be increased, which we showed to be the most significant parameter in AO design. The strong significance of the binding energy of PMO-target complexes (i.e., free energy of AO-target compared to free energy of the target) and PMO length to bioactivity suggests that PMO bioactivity depends on stability of the PMO-target complex, and implies that bioactive PMOs act by interference of target RNA folding. Computational analysis revealed that the thermodynamics of binding of active PMOs to their target site had a dramatic effect on the secondary folded structure of the RNA (data not shown). It is likely that these changes in secondary structure would have a profound effect on the binding of SR proteins to the RNA, thereby disrupting splicing, and exon skipping would ensue.
[0071] Overlap of a PMO target site with a binding site motif for the SR protein SF2/ASF (BRCA1), as predicted by ESEfinder, showed a significant association to PMO bioactivity. This partly confirms the work of Aartsma-Rus et al. [18], who observed marginally significantly higher ESEfinder values for SF2/ASF and SC35 motifs for effective AOs when compared to inactive AOs. SC35 and SF2/ASF motifs are the two most abundant proteins assessed by ESEfinder. The reason why we do not see any significance of overlap with SC35 motif to PMO bioactivity may be due to the difference in AO chemistry used, and the number of AOs assessed. However Aartsma-Rus et al. [18] did note that not every bioactive AO has a high value for any of the SR protein binding motifs, and some inactive AOs have high values. The apparent weakness and unreliability of SR protein binding motifs as design tools for AOs may be a reflection of the lack of precision of the predictive software used. Overlap of PMO target site with exonic splicing silencers appears to show a correlation with bioactivity in Spearman's rank order test analysis. Such a correlation would be counter-intuitive and the true significance questionable. Again the strength of the predictive software used may be in doubt. It should be noted that the software programmes used predict SR binding motifs on the linear exon sequence. The availability of these predicted motifs to bind SR proteins, or for binding PMOs to disrupt the binding of these proteins, is directly related to the folding of the pre-mRNA. The discrepancy in the relative significance of secondary RNA structure and SR protein binding motifs may be due to active PMOs disrupting SR protein binding, not sterically but indirectly, by altering the secondary pre-mRNA structure. A very recent study has shown the importance of co-transcriptional pre-mRNA folding in determining the accessibility of AO target sites and their effective bioactivity, and showed a direct correlation between AO bioactivity and potential interaction with pre-mRNA [31].
[0072] It has been previously reported that ESE sites located within 70 nucleotides of a splice site are more active than ESE sites beyond this distance [32]. Our results partially support this; PMOs with their target site closer to the splice acceptor site are significantly more bioactive. However distance of the PMO target site to the splice donor site showed no statistical significance to bioactivity. This bias has been previously reported for the analyses of 2′OMePS AOs [18, 19], and may be related to the demonstration, by Patzel et al. [33], of the importance of an unstructured 5′ end of RNA in the initiation of hybridization of oligonucleotide binding. This would suggest that targeting any significant parameters located in the 5′ part of an exon may increase the probability of designing a bioactive AO.
[0073] In conclusion, our findings show that no single design tool is likely to be sufficient in isolation to allow the design of a bioactive AO, and empirical analysis is still required. However this study has highlighted the potential of using a combination of significant PMO parameters/design tools as a powerful aid in the design of bioactive PMOs. Linear discriminant analysis revealed that using the parameters of PMO length, overlap with SF2/ASF (BRCA1) motif and hexamer array hybridization data in combination would have an 80% chance of designing a bioactive PMO, which is an exciting and suprising finding, and should be exploited in further studies.
[0000]
TABLE 1
Table 1: Table summarizing the characteristics of PMOs used
Targeted
Optimol
%
Exon-PMO
PMO-PMO
Ends in open
Distance from
PMO
exon
conc.
Skip a
Length
% GC
binding energy
binding energy
% open b
loops b
donor
acceptor
h53B1
53
500
0
25
28
−22.1
−12.1
53.3
1
119
68
h53C1
53
500
0
25
48
−32.4
−9.8
46.7
2
79
108
h53C2
53
500
0
25
56
−31.3
−12.7
33.3
1
72
115
h53C3
53
500
0
25
60
−34.6
−13.7
26.7
1
60
127
h53D1
53
500
0
25
52
−34.1
−13.4
30
1
39
148
h45A30/4
45
500
0
30
43
−35.2
−7.5
40
1
43
93
h45A30/6
45
500
0
30
53
−42.4
−26.9
46.7
2
9
137
h46A10
46
500
0
25
40
−35.3
−1.7
23.3
1
63
60
h46A30/6
53
500
0
30
40
−42.1
−10.1
56.7
0
5
113
h53D2
46
500
0.1
25
48
−36.5
−14.5
40
2
30
157
h46A5
53
500
0.2
25
36
−33.9
−7.9
53.3
0
10
113
h53A6
53
500
0.3
25
48
−35.3
−8.5
43.3
2
138
49
h53B2
53
500
0.6
25
48
−30.1
−11.3
23.3
1
108
79
h46A11
46
500
0.6
25
20
−24.5
−1.5
43.3
0
0
143
h46A30/8
46
500
1.5
30
30
−34.2
−1.8
46.7
0
0
136
h45A30/7
45
500
1.6
30
50
−46.1
−4.7
73.3
0
0
158
h45A30/8
45
500
1.6
30
40
−39.3
−13.7
53.3
1
76
70
h53A3
53
500
2
25
56
−36.7
−13.7
36.7
0
147
40
h46A9
46
500
2.1
25
28
−31.5
−7.6
36.7
1
109
14
h53B3
53
500
3
25
48
−34.5
−5.5
48
2
98
89
h53D3
53
500
3.7
25
36
−34.3
−11.2
40
1
18
169
h44B30/8
44
500
4.6
30
37
−28.3
−23.5
40
1
34
84
h44B30/4
44
50
5
30
43
−38.2
−14.6
40
0
54
64
h46A6
46
100
5.4
25
36
−31.5
−8
46.7
1
0
123
h46A8
46
500
5.4
25
32
−28.6
0
20
1
76
47
h45A30/3
45
500
6.3
30
40
−35.5
−11.8
60
1
108
38
h53D5
53
500
7.9
25
36
−31.5
−3.3
66.7
1
0
187
h46A1
46
100
8.3
25
48
−35.7
−11.9
53.3
1
38
85
h53A5
53
250
9
25
48
−35.5
−8.5
43.3
2
141
46
h46A7
46
500
9.1
25
32
−34.8
−5.6
36.7
1
123
0
h53A30/5
53
100
9.4
30
47
−42.4
−11.3
46.7
1
141
41
h53A2
53
100
9.7
25
56
−36.1
−17.4
46.7
1
150
37
h53A4
53
500
10.5
25
48
−34.3
−8.5
20
0
144
43
h45A30/5
45
500
11.2
30
63
−44
−21.1
26.7
0
17
129
h53D4
53
500
12.3
25
32
−30.9
−9.2
63.3
1
6
181
h53A1
53
100
12.7
25
52
−38.6
−17.4
50
2
153
34
A25
51
250
14.9
25
36
−29.3
−11.6
66.7
2
146
62
h46A2
46
500
15.6
25
44
−31.2
−10.6
56.7
1
33
90
h46A30/7
46
500
18.5
30
30
−34.2
−6.2
53.3
1
0
141
h46A4
46
100
21.2
25
44
−39.9
−6.3
56.7
2
20
103
h44C30/2
44
50
22
30
33
−38
−7.4
36.7
1
7
111
h44B30/7
44
100
26
30
37
−33.9
−10.9
26.7
1
39
79
h51A
51
500
26.3
30
43
−40.3
−15
70
1
137
65
h44B30/6
44
500
32.5
30
37
−34.6
−9.6
30
2
44
74
h44C30/3
44
500
35
30
33
−38.9
−13.8
30
1
2
116
h44B30/1
44
100
35
30
33
−35.2
−7.1
66.7
1
69
49
h53A30/6
53
500
35.9
30
47
−42.3
−8.5
56.7
1
338
44
h53A30/4
53
100
38.6
30
50
−43.4
−17.4
43.3
1
144
38
h44C30/1
44
100
42
30
37
−41.1
−10.4
50
1
12
106
h46A3
46
100
49.7
25
48
−43.1
−5.2
56.7
2
28
95
h44A30/3
44
250
52.1
30
37
−42.5
−8.6
56.7
1
99
19
h53A30/1
53
100
52.4
30
50
−48.1
−17.4
56.7
1
153
29
h44B30/3
44
500
61
30
43
−35.4
−11.4
30
0
59
59
h44B30/5
44
500
63.3
30
40
−35.9
−14.6
30
1
49
69
h45A30/1
45
500
64.5
30
60
−49.7
−11
36.7
1
146
0
h46A30/3
46
500
74.6
30
43
−49.8
−6.1
73.3
2
23
95
h46A30/1
46
500
75.6
30
47
−43.5
−12.3
63.3
0
33
85
h46A30/5
46
500
76.7
30
40
−49.2
−6.3
70
1
15
103
h53A30/3
53
100
80.1
30
53
−44.6
−17.4
53.3
1
147
35
h44B30/2
44
500
80.5
30
37
−36.9
−10.7
50
1
64
54
h53A30/2
53
100
87.2
30
53
−45.1
−17.4
63.3
1
150
32
h46A30/4
46
500
87.3
30
40
−47.5
−6.3
73.3
2
20
98
h46A30/2
46
500
87.9
30
47
−49.1
−13.4
63.3
2
28
90
h45A30/2
45
500
91.4
30
60
−46.6
−13
20
1
142
4
h44A30/2
44
500
95
30
43
−44
−8.6
40
0
104
14
h44A30/1
44
250
97
30
47
−47.5
−11.2
46.7
1
109
9
%
% overlap with
% Rescue
% overlap with
overlap with
ESE finder values over threshold c
PMO
hybrid. peak
ESE sites
Rescue ESE
PESE
PESS
SF2/ASF
BRCA1
SC35
SRp40
SRp55
Tra2B
9G8
h53B1
0
5
56
40
40
0
9.26
3.62
10.66
0
5.06
1.1
h53C1
0
6
52
72
0
4.19
6.72
0
2.04
0
24.04
28.68
h53C2
0
1
24
60
0
4.19
6.72
10.2
4.38
0
0
8.28
h53C3
0
1
24
32
0
3.49
6.41
10.2
4.38
6.86
0
14.18
h53D1
0
4
40
32
0
0.52
0
18.68
0
6.86
0
12.71
h45A30/4
100
4
40
0
0
6.29
4.8
5.9
17.91
0
18.18
8.14
h45A30/6
100
4
40
0
0
11.64
7.34
5.04
1.38
0
7.25
16.53
h46A10
0
7
60
48
8
2.21
0
2.7
2.88
0
5.11
23.85
h46A30/6
0
7
40
50
0
0
0
0
5.09
0
24.04
6.94
h53D2
0
6
44
32
0
0.52
1.8
18.68
0.42
0
0
12.71
h46A5
0
7
48
44
0
0
0
0
5.09
0
24.04
6.94
h53A6
92
2
36
28
32
6.58
7.26
0
0
0
7.25
11.9
h53B2
0
5
60
60
0
0
9.26
3.62
4.73
0
5.06
8.28
h46A11
0
2
36
12
52
0
0
0
1.02
0
0
2.04
h46A30/8
0
1
27
27
43
0
0
0
1.02
0
0
2.04
h45A30/7
100
9
47
0
0
6.34
7.34
0
0.6
0
18.18
8.14
h45A30/8
100
4
47
0
0
0
0
5.9
2.4
0
18.18
17.14
h53A3
0
3
32
60
0
6.58
7.26
0
3.12
0
7.25
11.9
h46A9
0
8
48
25
0
0
7.87
0
0
0
24.04
7.14
h53B3
0
8
72
64
0
3.49
9.26
3.44
4.73
0
24.04
28.68
h53D3
0
9
64
0
0
0
1.8
0
6.95
0
24.04
10.49
h44B30/8
0
7
57
27
13
2.85
8.64
7.06
1.38
0
10.92
19.02
h44B30/4
0
8
47
37
27
1.98
8.64
6.14
10.12
0
7.25
8.28
h46A6
0
7
72
64
0
0
0
0
5.09
0
24.04
6.94
h46A8
0
5
56
24
60
2.21
0
3.56
2.88
0
0
23.68
h45A30/3
100
9
87
30
0
0
6.18
3.07
4.73
0.45
24.04
28.68
h53D5
0
14
92
44
0
8.5
11.95
0
7.67
0.33
24.04
7.14
h46A1
100
3
20
40
0
2.62
20.26
6.63
6.17
0
0
5.12
h53A5
100
3
36
36
20
6.58
7.26
0
3.12
0
7.25
11.9
h46A7
0
9
64
44
0
0
0
6.02
4.2
0
24.04
28.68
h53A30/5
100
5
47
47
17
6.58
7.26
0
3.12
0
7.25
11.9
h53A2
100
4
32
72
0
6.58
7.26
0
3.12
0
7.25
19.02
h53A4
100
4
28
48
8
6.58
7.26
0
3.12
0
7.25
11.9
h45A30/5
100
2
23
0
0
11.64
13.49
5.04
1.38
0
7.25
16.53
h53D4
0
16
96
24
0
8.5
11.95
0
7.67
0.33
24.04
7.14
h53A1
92
7
56
84
0
6.58
7.26
0
3.12
0
24.04
19.02
A25
0
1
24
12
32
1.22
13.72
0
0
0
0
0
h46A2
100
5
40
40
0
2.62
20.26
6.63
6.17
00
13.11
5.12
h46A30/7
0
2
20
10
43
0
0
0
1.02
0
0
2.1
h46A4
46
8
60
40
0
0
0
0
5.09
0
24.04
6.94
h44C30/2
0
3
33
10
63
0.52
5.72
0
0
0
9.46
5.6
h44B30/7
0
6
40
30
27
2.85
8.64
7.06
1.38
0
10.92
19.02
h51A
0
2
40
3
27
1.22
13.72
0
0
0
0
4.45
h44B30/6
0
8
37
20
27
2.85
8.64
0
1.92
0
10.92
19.02
h44C30/3
0
2
33
0
63
0
0
0
6.44
0
9.46
5.6
h44B30/1
0
6
67
33
30
0
0
6.14
10.12
0
10.92
8.28
h53A30/6
100
5
48
37
27
6.58
7.26
0
3.12
0
7.25
11.9
h53A30/4
100
4
43
57
7
6.58
7.26
0
3.12
0
7.25
11.9
h44C30/1
0
3
43
27
63
0.52
5.72
7.06
0
0
9.46
5.6
h46A3
100
5
40
40
0
2.62
20.26
6.03
6.17
0
13.11
5.12
h44A30/3
0
3
23
0
77
0
13.26
0
0
0
0
11.3
h53A30/1
92
9
60
86
0
6.58
7.26
0
3.12
0
24.04
19.02
h44B30/3
0
5
47
37
33
0
0
6.14
10.12
0
7.25
8.28
h44B30/5
0
10
63
37
27
1.98
8.64
6.14
1.92
0
10.92
19.02
h45A30/1
100
2
0
0
6.7
3.43
8.64
5.16
3.54
3.57
0
20.56
h46A30/3
100
5
40
13
0
0
0.57
0
6.17
0
13.11
5.12
h46A30/1
100
5
33
33
0
2.62
20.26
6.63
6.17
0
13.11
5.12
h46A30/5
46
12
67
50
0
0
0
0
5.09
0
24.04
6.94
h53A30/3
100
6
43
67
0
6.58
7.26
0
3.12
0
24.04
19.02
h44B30/2
0
5
50
37
37
0
0
6.14
10.12
0
7.25
8.28
h53A30/2
100
8
53
77
0
6.58
7.26
0
3.12
0
24.04
19.02
h46A30/4
85
8
50
43
0
0
0.57
0
5.09
0
24.04
5.12
h46A30/2
100
5
33
33
0
2.62
20.26
6.63
6.17
0
13.11
5.12
h45A30/2
100
0
0
0
20
3.43
10.41
5.16
3.54
3.57
0
20.56
h44A30/2
0
3
27
0
63
0
13.26
0
0
0
0
11.3
h44A30/1
0
4
43
0
47
0
13.26
0
2.76
0
0
11.3
PMOs are ranked in order of efficacy and characteristics of the PMOs and their target sites listed.
a calculated as % skipped amplicon relative to total amplicon (i.e. skipped plus full length) as assessed by densitometric analysis of RT-PCR gels.
b calculated as % on PMO target site in open structures on predicted RNA secondary structure obtained using MFOLD analysis. The position of the PMO target sites relative to open loops in the RNA secondary structure is listed (0 = no ends in open loops, 1 = one end in an open loop, 2 = both ends in open loops).
c In analyses, SR binding sites were predicted using splice sequence finder (http://www.umd.be/SSF/) software. Values above threshold are given for PMOs whose target sites cover 50% or more of potential SR binding sites for SF2/ASF, BRCA1, SC35, SRp40, SRp55, Tra2β and 9G8.
[0000]
TABLE 2
Table 2: The correlation of significant design parameters and PMO target site
properties to skipping efficacy
% overlap with
% overlap with
PMO-target
% open
Distance from
hybridisation
strongest
% overlap with
Comparison
binding energy
conformation
Length
acceptor site
peak
hybrid. peak
BRCA1 motif
Ineffective vs Effective
0.001
0.094
0.017
0.004
0.056
0.003
0.026
Ineffective vs 5-25% skip
0.534
0.288
1
0.163
0.107
0.034
0.205
Ineffective vs 25-50% skip
0.02
0.316
0.014
0.067
0.614
0.195
0.079
Ineffective vs 50-75% skip
0.002
0.438
0.012
0.005
0.352
0.084
0.341
Ineffective vs 75-100% skip
<0.001
0.025
0.002
0.003
0.045
0.002
0.091
Ineffective vs >50% skip
<0.001
0.052
<0.001
<0.001
0.05
0.005
0.046
Spearmans correlation
−0.618
0.275
0.545
−0.421
0.258
0.46
0.261
coefficient
Spearmans p value
0
0.0259
0
0
0.0363
0
0.0341
To establish the significance of design parameters and PMO target site properties to bioactivity, Mann-Whitney rank sum test analysis was performed for each, comparing ineffective (inactive) PMOs to the different groups of PMOs, subdivided (in the column headed “Comparison”) according to bioactivity (efficacy). Criteria with p-values less than 0.05 in one or more comparisons are shown. The correlation of these variables to bioactivity is confirmed by Spearman rank order test analysis, for which Spearman correlation coefficients and p-values are given.
[0000]
TABLE 3
Table 3: Linear discriminant analysis of effective
and ineffective PMOs
Classification
Average
Group
Effective
Ineffective
Total
Error rate
score
Effective
40
4
44
0.09
0.741
Ineffective
9
13
22
0.41
0.512
0-5% skip
9
13
22
0.41
0.512
5-25% skip
16
4
20
0.2
0.621
25-50% skip
9
0
9
0
0.806
50-75% skip
6
0
6
0
0.827
75-100% skip
10
0
10
0
0.857
Linear discriminant analysis [34] was used to predict the classification of PMOs on the basis of their PMO-target binding energy, overlap of PMO target site with a hybridization peak, and overlap of PMO target site with an ASF/SF2 (BRCA1) motif. PMOs have been grouped on the basis of their experimental bioactivity (“Group” column), and PMOs within each group predicted as “Effective” (bioactive) or “Ineffective” (inactive), as indicated by the column headings, according to the parameters used in the statistical analysis. The error rate for wrongly classifying a PMO, and the average score are given for each subgroup of PMO.
Example 2
[0074] Here, the inventors show the comparative analysis of a series of PMOs targeted to exon 53, skipping of which would have the potential to treat a further 8% of DMD patients with genomic deletions on the Leiden database compared to skipping of exon 51 which has the potential to treat 13% of DMD patients [37]. An array of overlapping PMOs were designed for the targeting of exon 53 as described previously [38]. These were all tested initially in normal human skeletal muscle cells (hSkMCs), since these are more readily available than patient cells. PMOs that showed greatest skipping efficacy were further tested in cells from a DMD patient with a relevant deletion (del 45-52). The PMOs with greatest efficacy, in terms of concentration and stability, were evaluated by performing dose-response and time-course studies. Findings from these experiments were supported by in vivo studies in a mouse model transgenic for the entire human dystrophin locus [8]. Collectively, this work suggests that one particular PMO (A, h53A30/1, +30+59) produced the most robust skipping of exon 53, and should be considered the sequence of choice for any upcoming PMO clinical trial.
Materials and Methods
AO Design
[0075] Twenty-three overlapping AOs to exon 53 were designed as described above in Example 1.
Cell Culture and AO Transfection
[0076] Transfections were performed in two centres (Royal Holloway, London UK (RHUL) and UCL Institute of Child Health, London UK (UCL)) and by two different methods (liposome-carrier of leashed PMOs in normal cells (RHUL), and by nucleofection of naked PMOs in patient cells (UCL)). AOs were transfected into normal human primary muscle cells (TCS Cellworks, Buckingham, UK) and into patient primary skeletal muscle cultures obtained from muscle biopsies taken at the Dubowitz Neuromuscular Unit, UCL Institute of Child Health (London, UK), with the approval of the institutional ethics committee. Normal hSkMCs were cultured and transfected with leashed PMOs, using 1:4 lipofectin, as described previously [4]. To minimize any influence of leash design on PMO uptake and subsequent bioactivity, the DNA sequences in the leashes were of the same length (17mers for the 25mer PMOs or 20mers for the 30mer PMOs) and were completely complementary to the 3′-most 17 or 25 nt of each PMO. The phosphorothioate caps of 5 nt at each end were not complementary to the PMOs, and had the same sequences for every leash.
DMD Patient Primary Myoblast Culture
[0077] Skeletal muscle biopsy samples were taken from a diagnostic biopsy of the quadriceps from a DMD patient with a deletion of exons 45-52. Informed consent was obtained before any processing of samples. Muscle precursor cells were prepared from the biopsy sample by sharp dissection into 1 mm 3 pieces and disaggregated in solution containing HEPES (7.2 mg/ml), NaCl (7.6 mg/ml), KCl (0.224 mg/ml) Glucose (2 mg/ml) Phenol Red (1.1 μg/ml) 0.05% Trypsin-0.02% EDTA (Invitrogen, Paisley, UK) in distilled water, three times at 37° C. for 15 minutes in Wheaton flasks with vigorous stirring. Isolated cells were plated in non-coated plastic flasks and cultured in Skeletal Muscle Growth Media (Promocell, Heidelberg, Germany) supplemented with 10% Foetal Bovine Serum (PAA Laboratories, Yeovil, UK), 4 mM L-glutamine and 5 μg/ml gentamycin (Sigma-Aldrich, Poole, UK) at 37° C. in 5% CO 2 .
Nucleofection of DMD Primary Myoblasts
[0078] Between 2×10 5 and 1×10 6 cells/ml were pelleted and resuspended in 100 μl of solution V (Amaxa Biosystems, Cologne, Germany). The appropriate PMO to skip exon 53 was added to the cuvette provided, sufficient to give the concentrations described, followed by the cell suspension, and nucleofected using the Amaxa nucleofector 2, program B32. 500 μl of media was added to the cuvette immediately following nucleofection. This suspension was transferred to a 6 well plate in differentiation medium. Nucleofected cells were maintained in differentiation media for 3-21 days post treatment before extraction of RNA or protein.
Lactate Dehydrogenase Cytotoxicity Assay
[0079] A sample of medium was taken 24 hours post-transfection to assess cytotoxicity by release of lactate dehydrogenase (LDH) into the medium, using the LDH Cytotoxicity Detection Kit (Roche, Burgess Hill, UK), following the manufacturer's instructions. The mean of three readings for each sample was recorded, with medium only, untreated and dead controls. The readings were normalised for background (minus medium only) and percentage toxicity expressed as [(sample−untreated)/(dead−untreated)×100].
RNA Isolation and Reverse Transcription Polymerase Chain Reaction Analysis
[0080] As with cell culture, two different techniques were used in the two centres involved in this study for isolating RNA and its analysis by RT-PCR, as described previously [4]. PCR products were analysed on 1.5% (w/v) agarose gels in Tris-borate/EDTA buffer. Skipping efficiencies were determined by quantification of the full length and skipped PCR products by densitometry using GeneTools software (Syngene, Cambridge, UK).
Sequence Analysis
[0081] RT-PCR products were excised from agarose gels and extracted with a QIAquick gel extraction kit (Qiagen, Crawley, UK). Direct DNA sequencing was carried out by the MRC Genomics Core Facility.
Western Blot Analysis of Dystrophin Protein
[0082] DMD patient cells, transfected as described and cultured in differentiation medium, were harvested 7, 14 or 21 days post-transfection. 4×10 5 cells were pelleted and resuspended in 50 μl of loading buffer (75 mM Tris-HCl pH 6.8, 15% sodium dodecyl sulphate, 5% β-mercaptoethanol, 2% glycerol, 0.5% bromophenol blue and complete mini protease inhibitor tablet). Samples were incubated at 95° C. for 5 minutes and centrifuged at 18,000×g for 5 minutes. 20 μl of sample was loaded per well in a 6% polyacrylamide gel with 4% stacking gel. Protein from CHQ5B cells differentiated for 7 days was used as a positive control for dystrophin. Gels were electrophoresed for 5 hours at 100V before blotting on nitrocellulose membrane at 200 mA overnight on ice. Blots were stained with Protogold to assess protein loading, then blocked in 10% non-fat milk in PBS with 2% tween (PBST) for 3 hours. Blots were probed with antibodies to dystrophin, NCL-DYS1 (Vector Labs, Peterborough, UK) diluted 1:40 and to dysferlin, Hamlet1 (Vector Labs) diluted 1:300 in 3% non-fat milk/PBST. An anti-mouse, biotinylated secondary antibody (diluted 1:2000; GE Healthcare, Amersham, UK) and streptavidin/horse radish peroxidise conjugated antibody (1:10,000; Dako, Ely, UK) allowed visualisation in a luminol-HRP chemiluminescence reaction (ECL-Plus; GE Healthcare) on Hyperfilm (GE Healthcare), exposed at intervals from 10 seconds to 4 minutes.
Transgenic Human DMD Mice
[0083] A transgenic mouse expressing a complete copy of the human DMD gene has been generated [8, 39]. Experiments were performed at the Leiden University Medical Center, with the authorization of the Animal Experimental Commission (UDEC) of the Medical Faculty of Leiden University as described previously [4].
Results
[0084] Twenty-three PMOs were designed to target exon 53, as described previously [38]. Briefly, SR protein binding motifs, RNA secondary structure and accessibility to binding as determined by hexamer hybridization array analysis, were used as aids to design ( FIG. 1 ). Table 4 summarises the names and target sequence characteristics of these PMOs. These PMOs were initially characterized in normal human skeletal muscle cells (at RHUL). The most active were then directly compared to the PMO targeting the sequence previously identified as most bioactive by Wilton et al. [19] in exon 53-skippable patient cells (at UCL), and in the humanised DMD mouse (at LUMC).
Comparison of PMOs to Exon 53 in Normal Human Skeletal Muscle Cells
[0085] An array of seventeen 25mer leashed PMOs were transfected, at a concentration of 500 nM, into normal human skeletal muscle myoblast cultures using lipofectin. Of these seventeen, only four produced consistent levels of exon skipping considered to be above background i.e. over 5% skipping [38], as assessed by densitometric analysis ( FIG. 6 a ). These were PMO-A, -B, -C and -D, which targeted exon 53 at positions +35+59, +38+62, +41+65 and +44+68 respectively. The levels of exon skipping produced were as follows: PMO-A, 12.7%; PMO-B, 9.7%; PMO-C, 10.5%; and PMO-D, 9.0%. When nucleofection was used as a means of introducing naked PMOs into the cells, higher levels of exon skipping were observed for PMO-A and PMO-B only, with 300 nM doses producing 41.2% and 34.3% exon skipping, respectively. The superiority of nucleofection over lipofection has been observed by others (Wells et al., in preparation). However no exon skipping was evident following nucleofection with any of the other naked 25mer PMOs tested (data not shown).
[0086] A 3 nt-stepped array of 30mer PMOs was then designed to target the region of exon 53 (position +30 to +74) associated with exon skipping activity by the 25mer PMOs. Following lipofection into normal human skeletal muscle myoblast cultures at a concentration of 500 nM, PMO-G (+30+59), PMO-H (+33+62), PMO-I (+36+65), PMO-J (+39+68) and PMO-K (+42+71) gave reproducible exon skipping above background ( FIG. 6 b ), while PMO-L (+45+74) was inactive. The levels of exon skipping produced were as follows: PMO-G, 37.1%; PMO-H, 44.5%; PMO-I, 27.4%; PMO-J, 33.0%; and PMO-K, 13.0%. The concentration dependence of exon skipping by the more active 30mer PMOs was examined further ( FIG. 7 a ). PMO-H and PMO-I were able to produce convincing skipping at concentrations as low as 25 nM, while PMO-G was active at 50 nM and PMO-J at 75 nM. The exon skipping produced by these 30mer PMOs was shown to be persistent, surviving the lifetime of the cultures (14 days) ( FIG. 7 b and data not shown). When unleashed 30mer PMOs were introduced into normal muscle cultures by nucleofection, high levels of exon skipping were also observed. For example, at 300 nM, PMO-G and PMO-H gave over 80% skipping of exon 53 (data not shown).
Comparison of PMOs to Exon 53 in DMD Patient Cells
[0087] The PMOs, both 25mer and 30mer, that produced the highest levels of DMD exon 53 skipping in normal skeletal muscle cultures, were then compared to each other for bioactivity in DMD patient (del 45-52) cells, and were also compared to an additional reagent, PMO-M (+39+69), described previously [19]. This comparative evaluation was performed in a blinded fashion. When tested and compared directly at 300 nM doses by nucleofection, PMO-G, PMO-H and PMO-A were most active producing in the order of 60% exon skipping ( FIG. 8 ). The other PMOs tested produced the following exon skipping levels: PMO-I, 45%; PMO-B, 41%; PMO-J, 27%; PMO-M, 26%. All the other PMOs tested gave exon skipping at lower levels of between 10 and 20%.
[0088] When the concentration dependence of exon skipping was examined for the most bioactive PMOs, levels approaching 30% were evident for PMO-G and PMO-H at concentrations as low as 25 nM ( FIG. 9 a, b ). Similar levels of skipping were only achieved by PMO-A, PMO-B and PMO-M at 100 nM, while PMO-I needed to be present at 200 nM to produce over 30% exon skipping ( FIG. 9 a, b ). There was no evidence that any of the PMOs tested caused cellular cytotoxicity relative to mock-transfected controls, as assessed by lactate dehydrogenase release into culture medium (results not shown). The exon skipping produced by the six most bioactive PMOs was shown to be persistent, lasting for up to 10 days after transfection, with over 60% exon skipping observed for the lifetime of the cultures for PMO-A, PMO-G and PMO-H ( FIG. 10 a, b ). Exon skipping was shown to persist for 21 days for PMO-A and PMO-G ( FIG. 10 c ).
[0089] Western blot analysis of DMD patient (del 45-52) cell lysates, treated in culture with the most bioactive 25mers (PMO-A and PMO-B) and longer PMOs (PMO-G, PMO-H, PMO-I and PMO-M) is shown in FIG. 10 e . De novo expression of dystrophin protein was evident with all six PMOs, but was most pronounced with PMO-H, PMO-I, PMO-G and PMO-A, producing 50%, 45%, 33% and 26% dystrophin expression, respectively, relative to the positive control, and seemingly weakest with PMO-B and PMO-M (11% and 17% dystrophin expression respectively, relative to the positive control). However, the limitations of quantifying Western blots of this nature should be taken into account when interpreting the data.
Comparison of PMOs to Exon 53 in Humanised DMD Mouse
[0090] The hDMD mouse is a valuable tool for studying the processing of the human DMD gene in vivo, and as such provides a model for studying the in vivo action of PMOs, prior to clinical testing in patients. PMO-A, PMO-G, PMO-H, PMO-I and PMO-M were injected into the gastrocnemius muscle of hDMD mice, and RNA extracted from the muscles was analysed for exon 53 skipping ( FIG. 11 ). Skipping of exon 53 is evident for each of the PMOs tested; 8% for PMO-A, 7.6% for PMO-I, 7.2% for PMO-G, but to a slightly lower level of 4.8% for PMO-H. PMO-M produced exon skipping levels of less than 1%, which is the detection threshold for the system used.
[0091] It should be noted that the levels of exon skipping by each particular PMO was variable. This has been reported previously [8], and is likely to be due to the poor uptake into the non-dystrophic muscle of the hDMD mouse. However this does not compromise the importance of the finding that the PMOs tested here are able to elicit the targeted skipping of exon 53 in vivo.
[0092] Of the 24 PMOs tested, six (PMO-A, PMO-B, PMO-G, PMO-H, PMO-I and PMO-M) produced over 50% targeted skipping of exon 53 either in normal myotubes or in patient myotubes or both. The characteristics of these active PMOs and their target sites are summarised in Table 4. They all showed strong overlap (92%-100%) with the sequence shown to be accessible to binding on the hybridization array analysis, had similar GC content (50%-56%), but varying degrees of overlap (32%-60%) with ESE sites as predicted by Rescue ESE analysis, varying degrees of overlap with ESE sites and ESS sites (60%-86% and 0%-10%, respectively) as predicted by PESX analysis, and all showed overlap with two SR binding motifs (SF2/ASF, as defined by the BRCA1 algorithm, and SRp40). It should be noted that PMO-J, -K, -L and M had a common SNP of exon 53 (c7728C>T) in the last, fourth to last, seventh to last and second to last base, respectively of their target sites. There is the potential that this allelic mismatch could influence the binding and bioactivity of these PMOs. However, the more active PMOs (-A, -B, -G, -H and -I) all had their target sites away from the SNP, and the possible effect of a mismatch weakening binding and bioactivity is removed, and allows definitive comparisons between these PMOs to be made.
Discussion
[0093] The putative use of AOs to skip the exons which flank out-of-frame deletions is fast becoming a reality in the experimental intervention of DMD boys. Indeed the restoration of dystrophin expression in the TA muscle of four patients, injected with a 2′OMePS AO optimised to target exon 51 of the DMD gene, has been reported recently [11]. Moreover a clinical trial using a PMO targeting exon 51 has recently been completed in seven DMD boys in the UK (Muntoni et al, in preparation). However, the targeted skipping of exon 51 would have the potential to treat only 13% of DMD patients with genomic deletions on the Leiden database [37]. There is therefore a definite requirement for the optimisation of AOs to target other exons commonly mutated in DMD.
[0094] Although there have been many large screens of AO bioactivity in vitro [18, 19, 38, 40], no definite rules to guide AO design have become apparent. Previous studies in the mdx mouse model of DMD showed that AOs that targeted the donor splice site of exon 23 of the mouse DMD gene restored dystrophin expression [7]. However the targeting of AOs to the donor splice sites of exon 51 of the human DMD gene was ineffective at producing skipping [4], and it has been suggested that the ‘skippability’ of human DMD exons has no correlation with the predicted strength of the donor splice site [41]. It has been reported that exon skipping could be induced by the targeting of AOs to exonic splicing enhancer (ESE) motifs [18, 40]. These motifs are recognised by SR proteins, which facilitate exon splicing by recruiting splicing effectors (U1 and U2AF) to the donor splice site (reviewed by Cartegni et al.) [42]. However these motifs are divergent, poorly defined, their identification complex, and their strength as AO design tools dubious [38].
[0095] A comparative study of 66 PMOs designed to five different DMD exons demonstrated the significance of RNA secondary structure in relation to accessibility of the PMO target site and subsequent PMO bioactivity [38], as assessed by mfold software prediction of secondary structure [25], and a hybridization screen against a hexamer array [38]. PMOs that bound to their target more strongly, either as a result of being longer or in being able to access their target site more directly, were significantly more bioactive. The influence of AO length on bioactivity has been reported elsewhere [4, 30], and is further confirmed in the present study; all 30mers tested were more bioactive relative to their 25mer counterpart. The fact that 30mer PMOs were more bioactive than 25mer PMOs targeted to the same open/accessible sites on the exon, would suggest that strength of binding of PMO to the target site may be the most important factor in determining PMO bioactivity. These thermodynamic considerations have also been reported in a complementary study of 2′OMePS AOs [40]. However, it has also been reported that two overlapping 30mers were not as efficient as a 25mer at skipping mouse exon 23, indicating that oligomer length may only be important in some cases [4].
[0096] To ensure that the analysis of PMOs for the targeted skipping of exon 53 was not biased by any particular design strategy, seventeen 25mer PMOs were designed to cover the whole of exon 53, with stepwise arrays over suggested bioactive target sites, and then subsequently six 30mer PMOs were designed to target the sequence of exon 53 that showed an association with exon skipping for the 25mers tested. PMOs were designed and tested independently by two different groups (at RHUL and UWA), and then efficacy of the best thirteen sequences confirmed by two other independent groups (at UCL and LUMC). Such a collaborative approach has been used previously as a way of validating target sequences in DMD [4]. Human myoblasts allowed the controlled in vitro comparison of PMO sequences, and confirmation of skipping of exon 53 at the RNA level by certain PMOs in both normal cells and, perhaps more importantly, in DMD patient cells with a relevant mutation. These results were further borne out by the expression of dystrophin protein in the DMD cells treated with specific PMOs. Use of the humanised DMD mouse provided an in vivo setting to confirm correct exon exclusion prior to any planned clinical trial. The combined use of these three different systems (normal cells, patient cells and hDMD mouse) as tests of PMO bioactivity provided a reliable and coherent determination of optimal sequence(s) for the targeted skipping of exon 53.
[0097] When considering the data presented here as a whole, the superiority of the PMO targeting the sequence +30+59 (PMO-G, or h53A30/1), is strongly indicated. In normal myoblasts, nucleofection of PMO-G (300 nM) and liposomal-carrier mediated transfection of leashed PMO-G (500 nM) produced over 80% and over 50% skipping of exon 53, respectively, implying that it acts extremely efficiently within the cell. This was confirmed in patient cells. Indeed, this PMO generates the highest levels of exon skipping in patient cells over a range of concentrations (up to 200 nM) and, most important therapeutically, exerts its activity at concentrations as low as 25 nM. The exon skipping activity of this PMO is also persistent, with over 70% exon skipping for 7 days in culture, and over 60% exon skipping for up to three weeks. This would have important safety and cost implications as a genetic therapy for DMD patients with the appropriate deletions. PMO-G was also shown to skip exon 53 correctly in vivo. These RNA results were further confirmed by the detection of dystrophin protein at a high level in protein extracts from patient cells treated with PMO-G. Previous studies by the Leiden group [18] suggest that the optimal 2′OMePS AO is targeted to the sequence +46+63 of exon 53, producing exon skipping in up to 25% of transcripts in cultured cells and 7% in the hDMD mouse. This 2′OMePS AO shows some degree of overlap with the optimal PMOs reported here which strengthens our findings. The reason that our optimal PMO is more specific could be a (combined) consequence of the different AO chemistries, length of AO used, and the absolute target site of AO.
[0098] The sequence h53A30/1 we have identified appears to be more efficient than any of the previously reported AOs designed to skip exon 53 of the DMD gene, and this PMO therefore represents, at the present time, the optimal sequence for clinical trials in DMD boys.
[0000]
TABLE 4
Table 4: Table summarizing the characteristics of PMOs used
%
%
Exon-
PMO-
Ends
overlap
#
overlap
PMO
PMO
in
with
Rescue
with
Position
binding
binding
%
open
hybrid.
ESE
Rescue
PMO
Start
End
% GC
energy
energy
open b
loops b
peak
sites
ESE
A
h53A1
+35
+59
52
−38.6
−17.4
50
2
92
7
56
B
h53A2
+38
+62
56
−36.1
−17.4
46.7
1
100
4
32
C
h53A3
+41
+65
56
−36.7
−13.7
36.7
0
0
3
32
D
h53A4
+44
+68
48
−34.3
−8.5
20
0
100
4
28
E
h53A5
+47
+71
48
−35.5
−8.5
43.3
2
100
3
36
F
h53A6
+50
+74
48
−35.3
−8.5
43.3
2
92
2
36
N
h53B1
+69
+93
28
−22.1
−12.1
53.3
1
0
5
56
O
h53B2
+80
+104
48
−30.1
−11.3
23.3
1
0
5
60
P
h53B3
+90
+114
48
−34.5
−5.5
48
2
0
8
72
Q
h53C1
+109
+133
48
−32.4
−9.8
46.7
2
0
6
52
R
h53C2
+116
+140
56
−31.3
−12.7
33.3
1
0
1
24
S
h53C3
+128
+152
60
−34.6
−13.7
26.7
1
0
1
24
T
h53D1
+149
+173
52
−34.1
−13.4
30
1
0
4
40
U
h53D2
+158
+182
48
−36.5
−14.5
40
2
0
6
44
V
h53D3
+170
+194
36
−34.3
−11.2
40
1
0
9
64
W
h53D4
+182
+206
32
−30.9
−9.2
63.3
1
0
16
96
X
h53D5
+188
+212
36
−31.5
−3.3
66.7
1
0
14
92
G
h53A30/1
+30
+59
50
−48.1
−17.4
56.7
1
92
9
60
H
h53A30/2
+33
+62
53
−45.1
−17.4
63.3
1
100
8
53
I
h53A30/3
+36
+65
53
−44.6
−17.4
53.3
1
100
6
43
J
h53A30/4
+39
+68
50
−43.4
−17.4
43.3
1
100
4
43
K
h53A30/5
+42
+71
47
−42.4
−11.3
46.7
1
100
5
47
L
h53A30/6
+45
+74
47
−42.3
−8.5
56.7
1
100
5
48
M
H53A
+39
+69
52
−48.5
−17.4
48.4
2
100
4
45
% overlap
with
ESE finder values over threshold c
PMO
PESE
PESS
SF2/ASF
BRCA1
SC35
SRp40
SRp55
Tra2B
9G8
A
h53A1
84
0
6.58
7.26
0
3.12
0
24.04
19.02
B
h53A2
72
0
6.58
7.26
0
3.12
0
7.25
19.02
C
h53A3
60
0
6.58
7.26
0
3.12
0
7.25
11.9
D
h53A4
48
8
6.58
7.26
0
3.12
0
7.25
11.9
E
h53A5
36
20
6.58
7.26
0
3.12
0
7.25
11.9
F
h53A6
28
32
6.58
7.26
0
0
0
7.25
11.9
N
h53B1
40
40
0
9.26
3.62
10.66
0
5.06
1.1
O
h53B2
60
0
0
9.26
3.62
4.73
0
5.06
8.28
P
h53B3
64
0
3.49
9.26
3.44
4.73
0
24.04
28.68
Q
h53C1
72
0
4.19
6.72
0
2.04
0
24.04
28.68
R
h53C2
60
0
4.19
6.72
10.2
4.38
0
0
8.28
S
h53C3
32
0
3.49
6.41
10.2
4.38
6.86
0
14.18
T
h53D1
32
0
0.52
0
18.68
0
6.86
0
12.71
U
h53D2
32
0
0.52
1.8
18.68
0.42
0
0
12.71
V
h53D3
0
0
0
1.8
0
6.95
0
24.04
10.49
W
h53D4
24
0
8.5
11.95
0
7.67
0.33
24.04
7.14
X
h53D5
44
0
8.5
11.95
0
7.67
0.33
24.04
7.14
G
h53A30/1
86
0
6.58
7.26
0
3.12
0
24.04
19.02
H
h53A30/2
77
0
6.58
7.26
0
3.12
0
24.04
19.02
I
h53A30/3
67
0
6.58
7.26
0
3.12
0
24.04
19.02
J
h53A30/4
57
7
6.58
7.26
0
3.12
0
7.25
11.9
K
h53A30/5
47
17
6.58
7.26
0
3.12
0
7.25
11.9
L
h53A30/6
37
27
6.58
7.26
0
3.12
0
7.25
11.9
M
H53A
58
10
6.58
7.26
0
3.12
0
7.25
11.9
Characteristics of the PMOs and their target sites listed.
b calculated as % of PMO target site in open structures on predicted RNA secondary structure obtained using MFOLD analysis. The position of the PMO target sites relative to open loops in the RNA secondary structure is listed (0 = no ends in open loops, 1 = one end in an open loop, 2 = both ends in open loops).
c In the analyses, SR binding sites were predicted using splice sequence finder (http://www.umd.be/SSF/) software. Values above threshold are given for PMOs whose target sites cover 50% or more of potential binding sites for SF2/ASF, BRCA1, SC35, SRp40, SRp55, Tra2β and 9G8
REFERENCES
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2. Den Dunnen J T, Grootsscholten P M, Bakker E, Blonden L A, Ginjaar H B, Wapenaar M C, et al. (1989). Topography of the Duchenne muscular dystrophy (DMD) gene: FIGE and cDNA analysis of 194 cases reveals 115 deletions and 13 duplications. Am J Hum Genet; 45: 835-847.
3. van Deutekom J C, Bremmer-Bout M, Janson A A, Ginjaar I B, Baas F, den Dunnen J T, et al. (2001). Antisense-induced exon skipping restores dystrophin expression in DMD patient derived muscle cells. Hum Mol Genet; 10: 1547-1554.
4. Arechavala-Gomeza V, Graham I R, Popplewell L J, Adams A M, Aartsma-Rus A, Kinali M, et al. (2007). Comparative analysis of antisense oligonucleotide sequences for targeted skipping of exon 51 during pre-mRNA splicing in human muscle. Hum Gene Ther; 18: 798-810.
5. Mann C J, Honeyman K, Cheng A J, Ly T, Lloyd F, Fletcher S, et al. (2001). Antisense-induced exon skipping and synthesis of dystrophin in the mdx mouse. Proc Natl Acad Sci USA; 98: 42-47.
6. Lu Q L, Mann C J, Lou F, Bou-Gharios G, Morris G E, Xue S A, et al. (2003). Functional amounts of dystrophin produced by skipping the mutated exon in the mdx dystrophic mouse. Nat Med; 9: 1009-1014.
7. Graham I R, Hill V J, Manoharan M, Inamati G B, Dickson G (2004). Towards a therapeutic inhibition of dystrophin exon 23 splicing in mdx mouse muscle induced by antisense oligonucleotides (splicomers): target sequence optimisation using oligonucleotide arrays. J Gene Med; 6: 1149-1158.
8. Bremmer-Bout M, Aartsma-Rus A, de Meijer E J, Kaman W E, Janson A A, Vossen R H, et al. (2004). Targeted exon skipping in transgenic hDMD mice: A model for direct preclinical screening of human-specific antisense oligonucleotides. Mol Ther; 10: 232-240
9. Jearawiriyapaisarn N, Moulton H M, Buckley B, Roberts J, Sazani P, Fucharoen S, et al. (2008). Sustained dystrophin expression induced by peptide-conjugated morpholino oligomers in the muscles of mdx mice. Mol. Ther . June 10 (Epub).
10. Bertoni C. (2008). Clinical approaches in the treatment of Duchenne muscular dystrophy (DMD) using oligonucleotides. Front Biosci; 13: 517-527.
11. van Deutekom J C, Janson A A, Ginjaar I B, Franzhuzen W S, Aartsma-Rus A, Bremmer-Bout M, et al. (2007). Local antisense dystrophin restoration with antisense oligonucleotide PRO051. N Eng J Med; 357: 2677-2687.
12. Gebski B L, Mann C J, Fletcher S, Wilton S D (2003). Morpholino antisense oligonucleotide induced dystrophin exon 23 skipping in mdx mouse muscle. Hum Mol Genet; 12: 1801-1811.
13. Alter J, Lou F, Rabinowitz A, Yin H, Rosenfeld J, Wilton S D, et al. (2006). Systemic delivery of morpholino oligonucleotide restores dystrophin expression bodywide and improves dystrophic pathology. Nat Med; 12: 175-177.
14. Fletcher S, Honeyman K, Fall A M, Harding P L, Johnsen R D, Wilton S D (2006). Dystrophin expression in the mdx mouse after localized and systemic administration of a morpholino antisense oligonucleotide. J Gene Med; 8: 207-216.
15. McClorey G, Fall A M, Moulton H M, Iversen P L, Rasko J E, Ryan M, et al. (2006). Induced dystrophin exon skipping in human muscle explants. Neuromus Disorders; 16: 583-590.
16. McClorey G, Moulton H M, IversenPL, Fletcher S, Wilton S D (2006). Antisense oligonucleotide-induced exon skipping restores dystrophin expression in vitro in a canine model of DMD. Gene Ther; 13:1373-1381.
17. Arora V, Devi G R, Iversen P L (2004). Neutrally charged phosphorodiamidate morpholino antisense oligomers: uptake, efficacy and pharmacokinetics. Curr Pharm Biotechnol; 5: 431-439.
18. Aartsma-Rus A, De Winter C L, Janson A A M, Kaman W E, van Ommen G-JB, Den Dunnen J T, et al. (2005). Functional analysis of 114 exon-internal AONs for targeted DMD exon skipping: Indication for steric hindrance of SR protein binding sites. Oligonucleotides; 15: 284-297.
19. Wilton S D, Fall A M, Harding P L, McClorey G, Coleman C, Fletcher S (2007). Antisense oligonucleotide-induced exon skipping acroos the human dystrophin gene transcript. Mol Ther; 15: 1288-1296.
20. Cartegni L, Wang J, Zhu Z, Zhang M Q, Krainer A R (2003). ESEfinder: A web resource to identify exonic splicing enhancers. Nucleic Acids Res; 31: 3568-3571.
21. Smith P J, Zhang C, Wang J, Chew S L, Zhang M O, Krainer A R (2006). An increased specificity score matrix for the prediction of SF2/ASF-specific exonic splicing enhancers. Human Mol Genet; 15: 2490-2508.
22. Zhang X H, Chasin L H (2004). Computational definition of sequence motifs governing constitutive exon splicing. Genes Dev; 18: 1241-1250.
23. Zhang X H, Leslie C S, Chasin L A (2005). Computational searches for splicing signals. Methods; 37: 292-305.
24. Fairbrother W G, Yeh R F, Sharp P A, Burge C B (2002). Predictive identification of exonic splicing enhancers in human genes. Science; 297: 1007-1013.
25. Mathews D H, Sabina J, Zuker M, Turner D H (1999). Expanded sequence dependence of thermodynamic parameters improves prediction of RNA secondary structure. J Mol Biol; 288: 911-940.
26. Aartsma-Rus A, Bremmer-Bout M, Janson A A M, den Dunnen J T, van Ommen G-JB, van Deutekom J C T (2002). Targeted exon skipping as a potential gene correction therapy for Duchenne muscular dystrophy. Neuromus Disorders; 12: 871-877.
27. Aartsma-Rus A, Kaman W E, Weij R, den Dunnen J T, van Ommen G J, van Deutekom J C. (2006). Exploring the frontiers of therapeutic exon skipping for Duchenne muscular dystrophy by double targeting within one or multiple exons. Mol Ther; 14: 401-407.
28. Adams A M, Harding P L, Iversen P L, Coleman C, Fletcher S, Wilton S D. (2007). Antisense oligonucleotide induced exon skipping and the dystrophin gene transcript: cocktails and chemistries. BMC Mol Biol; 8: 57.
29. Vickers T A, Wyatt J R, Freier S M (2000). Effects of RNA secondary structure on cellular antisense activity. Nucleic Acids Res; 28: 1340-1347.
30. Harding P L, Fall A M, Honeyman K, Fletcher S, Wilton S D (2007). The influence of antisense oligonucleotide length on dystrophin exon skipping. Mol Ther; 15: 157-166.
31. Wee K B, Pramono Z A D, Wang J L, MacDorman K F, Lai P S, YeeWC (2008). Dynamics of co-translational pre-mRNA folding influences the induction of dystrophin exon skipping by antisense oligonucleotides. Plos one; 3: e1844.
32. Fairbrother W G, Yeo G W, Yeh R, Goldstein P, Mawson M, Sharp P A, et al. (2004). RESCUE-ESE identifies candidate exonic splicing enhancers in vertebrate exons. Nucleic Acids Res; 32: W187-190.
33. Patzel V, Steidl R, Kronenwell R, Haas R, Sczakiel G (1999). A theoretical approach to select effective antisense oligodeoxyribonucleotides at high statistical probability. Nucleic Acids Res; 27: 4328-4334.
34. Ihaka R, Gentleman R C (1996). R: A Language for Data Analysis and Graphics. Journal of Computational and Graphical Statistics; 15: 999-1013.
35. Moulton H M, Fletcher S, Neuman B W, McClorey G, Stein D A, Abes S, Wilton S D, Buchmeier M J, Lebleu B, Iversen P L (2007). Cell-penetrating peptide-morpholino conjugates alter pre-mRNA splicing of DMD (Duchenne muscular dystrophy) and inhibit murine coronavirus replication in vivo. Biochem. Soc. Trans. 35: 826-8.
36. Jearawiriyapaisarn N, Moulton H M, Buckley B, Roberts J, Sazani P, Fucharoen S, Iversen P L, Kole R (2008). Sustained Dystrophin Expression Induced by Peptide-conjugated Morpholino Oligomers in the Muscles of mdx Mice. Mol. Ther . June 10. Epub ahead of print.
37. Aartsma-Rus A, Fokkema I, Verschuuren J, Ginjaar I, van Deutekom J, van Ommen G J et al. Theoretic applicability of antisense-mediated exon skipping for Duchenne muscular dystrophy mutations. Hum Mutation 2009; Jan. 20 (Epub).
38. Popplewell L J, Trollet C, Dickson G, Graham I R. Design of phosphorodiamidate morpholino oligomers (PMOs) for the induction of exon skipping of the human DMD gene. Mol Ther 2009; Jan. 13 (Epub).
39. ‘tHoen PAC, de Meijer E J, Boer J M, Vossen R H, Turk R, Maatman R G et al. (2008) Generation and characterization of transgenic mice with the full-length human DMD gene. J Biol Chem; 283: 5899-5907.
40. Aartsma-Rus A, van Vliet L, Hirschi M, Janson A A, Heemskerk H, de Winter C L, et al. Guidelines for antisense oligonucleotide design and insight into splice-modulating mechanisms. Mol Ther 2008; Sep. 23 (Epub).
41. Aartsma-Rus A, van Ommen G J. Antisense-mediated exon skipping: A versatile tool with therapeutic and research applications. RNA 2007; 13: 1-16.
42. Cartegni L, Chew S L, Krainer A R. Listening to silence and understanding nonsense: Exonic mutations that affect splicing. Nat Rev Genet. 2002; 3: 285-298. | Molecules are provided for inducing or facilitating exon skipping in forming spliced mRNA products from pre-mRNA molecules in cells. The molecules may be provided directly as oligonucleotides or expression products of vectors that are administered to a subject. High rates of skipping can be achieved. High rates of skipping reduce the severity of a disease like Duchene Muscular Dystrophy so that the disease is more like Becker Muscular Dystrophy. This is a severe reduction in symptom severity and mortality. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates in general to the isolation/extraction from plant materials of pharmacologically active ingredients therein, and more particularly, to the extraction from marijuana plant parts of Delta-9-Tetrahydrocannabinol (THC) and other related compounds using one or more supercritical fluids. The present invention also provides a method of preparation of cigarettes (a drug delivery device) having differing specific concentrations of ingredients from the extracted marijuana leaves and other parts with the aid of spiking with either synthetic or natural compounds or mixture of compounds. In addition, placebo cigarettes can be prepared using the present method, having negligible quantities of Delta-9-THC therein. The isolated active compound or mixture of compounds can be used in different delivery devices for the treatment of pain.
BACKGROUND OF THE INVENTION
[0002] Marijuana plants have been used since antiquity for herbal medicine and intoxication. Marijuana has been reported as having more than 30 different medical uses such as treating pain, nausea and vomiting associated with chemotherapy, wasting syndrome and appetite stimulation for AIDS patients, glaucoma, and neurological symptoms including muscle spasticity.
[0003] During the past twenty years there has been a steady increase in the illicit use of opiates. Among the opiates, Cannabis sativa (marijuana) or parts thereof, the major pharmacologically active component of which is Δ 9 -tetrahydrocannabinol (Δ 9 -THC), continues to be the most frequently abused drug, especially among young adults and school children. As a result, concerns regarding the pathophysiology of marijuana on the human organ system have been investigated.
[0004] The primary route of administration of marijuana (Δ 9 -THC) is via smoking thereof. Marijuana smoking has been the topic of a number of clinical and basic research studies, which have focused on the mechanism of the addictive processes and the health hazards associated with marijuana use. One of the major drawbacks in these studies has been the unavailability of placebo marijuana cigarettes depleted of Δ 9 -THC (i.e., a control), and research marijuana cigarettes containing standardized amounts of Δ 9 -THC. These studies have been further complicated by a lack of quantitative information on the effective delivery of Δ 9 -THC resulting from the varied and unpredictable amount of Δ 9 -THC usually found in marijuana cigarettes.
[0005] Consistency of the content of Δ 9 -THC in marijuana cigarettes is desirable because it overcomes the natural variation of concentration of Δ 9 -THC present in the marijuana due to latitude, weather, and soil conditions. Moreover, drug product consistency is a basic tenet of pharmacology and toxicology, since it enables standardized dosing for regulatory and treatment purpose. Also, when interpreting studies purporting to show the harmful effects of smoked marijuana, cannabinoid effects cannot be separated from the effects of inhaling smoke from burning plant material and contaminants. In addition, placebo cigarettes are desired, as they may be used as control cigarettes in investigations to determine the psychological and biological effects, as well as health hazards, associated with marijuana smoking.
[0006] The current debate on medical use of marijuana over the health risk began nation wide. Several states passed ballot initiatives in support of medical marijuana. At the present time Δ 9 -THC, the primary active ingredient in marijuana is an FDA-approved drug marketed as MARINOL capsules. A study recently published by the Institute of Medicine recommended that as a rapid-onset delivery system, smoked marijuana may be given on a short-term basis to patients with debilitating symptoms (such as intractable pain or vomiting). It is also recommended that smoked marijuana may be administered as a first step towards the possible development of alternative cannabinoid delivery systems. Currently, MARINOL (sold as capsules in 2.5 mg, 5 mg and 10 mg strength) is the only cannabinoid with approval for marketing in the United States. Thus, different Δ 9 -THC strength cigarettes spiked from placebo marijuana would be valuable for marijuana researchers and patients.
[0007] A prerequisite for the manufacture of placebo cigarettes is the standardized decannabinized marijuana i.e., marijuana containing pharmacologically insignificant levels of Δ 9 -THC. Procedures for decannabinization of marijuana are needed that will not affect the color, texture and physical properties of the marijuana plant material, and yet be suitable for cigarette manufacturing.
[0008] The last 20 years have seen an intense interest in the use of supercritical fluids in separation science. Supercritical fluid extraction is defined as the use of supercritical fluids to selectively remove analytes from solid, semisolid and liquid matrices. A supercritical fluid exhibits gas-like mass transfer properties and liquid-like solubility properties, enabling it to carry out solvent extractions much more efficiently and rapidly than a solvent in the liquid state. The significant properties of supercritical fluids that relate to extraction processes are: (a) solvating power directly related to density, (b) relatively high diffusivity and low viscosity, and (c) minimal surface tension.
[0009] The limitations, concerns, and restrictions associated with conventional methods of extraction can easily be overcome by using supercritical fluid (SCF) extraction. Supercritical Fluid Extraction Systems (SCFE) have been used for selective extraction of valuable chemicals from various natural, as well as synthetic, matrices under environmentally safe operation. The composite device used for this extraction technique has several components, i.e., a high-pressure pump, extraction vessel, back pressure regulator, and analyte collection vessel, besides the source of solvent (e.g., CO 2 ).
[0010] Most current commercial applications of SCF extractions involve biologically produced materials. This SCF technique is particularly relevant to extraction of biological compounds in cases where there is a requirement for low temperature processing, high mass transfer rates and negligible carry over of solvent into the final product. A comparison of SCFE and Soxhlet extraction of several compounds (e.g. polychlorinated biphenyls) has been made, and it has been found that supercritical fluid extraction time is shorter than the extraction times associated with conventional methods.
[0011] In the past few decades, experimental efforts have concentrated on utilizing SCFE techniques for applications such as (a) extraction of aroma producing compounds from fruits and coffee, flavors from foods, eugenol from clove buds, lanolin from wool, nicotine from tobacco, (b) production of spice extracts with a natural composition, (c) production of caffeine-free coffee, and (d) isolation of specialty chemicals.
[0012] Essential oils from medicinal plants have been extracted by SCF. It was observed that the ester constituents of the extracted material were high because the possibility of hydrolysis is reduced. An optimization procedure for the SCF extraction of cocaine has also been investigated using a near critical mixture of CO 2 and polar modifiers to extract major alkaloids from poppy straw. The extraction of thebaine, codeine, and morphine has been achieved by percolating a mixture of carbon dioxide-methanol-water (70:24:6 w/w, respectively) at 45° C. and 200 bar through a column containing poppy straw (previously ground and sieved) for 20 minutes.
[0013] Other compounds that have been extracted using SCF extraction techniques include steroids, trichothecenes, and ouabin (a steroid derived glycoside with eight hydroxyl groups) using 100% CO 2 under various pressures at 40° C. The application of SCF extraction for direct extraction of active ingredients from a liquid pharmaceutical matrix has been described in the extraction of sulfamethoxazole and trimethoprim from SEPTRA infusion. The extraction was carried out to determine whether SCF extraction could be used to remove the polar drug from the polar matrix. Hydrocarbon and typically lipophillic compounds of relatively low polarity, e.g., esters, lactones and epoxides, can be extracted in the low pressure range (i.e. 70-100 bar), but strongly polar substances (sugars, amino acids) need higher pressures for extraction.
SUMMARY OF INVENTION
[0014] In order to overcome the deficiencies of the conventional methods discussed above, and to provide a marijuana cigarette having a consistent concentration of Δ 9 -THC and method of making same, a process is provided for the decannabinization of marijuana using supercritical fluid (SCF) extraction. In such process of the present invention, chromatographic methods (HPLC/GC) can be used to determine the amounts of Δ 9 -THC and other compounds in the marijuana and cigarettes.
[0015] In a first embodiment of the present invention, a process for the extraction of Delta-9-THC and other related pharmaceutically active compounds from marijuana plants is provided comprising super critical fluid extraction of Delta-9-THC, Delta-8-THC and related cannabinoids from marijuana plants using liquid carbon dioxide as a supercritical fluid.
[0016] In a second embodiment of the present invention according to the first embodiment above, the process further comprises the use of an organic cosolvent modifier in the extraction of Delta-9-THC, Delta-8-THC and other related pharmaceutically active compounds therein, from marijuana plants.
[0017] In a third embodiment of the present invention according to the first and second embodiments above, the supercritical fluids used in the supercritical fluid extraction process are one or more selected from the group comprising NH 3 , N 2 O, ethanol, pentane, and propane, and high purity carbon dioxides.
[0018] In a fourth embodiment of the present invention according to the first through third embodiments above, the super critical fluid extraction using CO 2 is preferably carried out at or above its critical temperature of 31.3° C. and at a pressure of 70 bar.
[0019] In a fifth embodiment according to the first through fourth embodiments above, the super critical fluid extraction process is carried out within an operating temperature range of from 31 to 120° C.
[0020] In a sixth embodiment of the present invention according to the first through fifth embodiments above, the supercritical fluid extraction process is carried out within an operating temperature range of from about 25-65° C.
[0021] In a seventh embodiment of the present invention according to the first through fifth embodiments above, the supercritical fluid extraction process is carried out within an operating temperature range of from about 30-65° C.
[0022] In an eighth embodiment of the present invention according to the first through fifth embodiments above, the supercritical fluid extraction process is carried out within an operating temperature range of from about 35-45° C.
[0023] In a ninth embodiment according to the first through eighth embodiments above, the supercritical fluid extraction process is carried out within a preferred pressure range of from about 70 to about 680 bar.
[0024] In a tenth embodiment of the present invention according to the first through eighth embodiments above, the supercritical fluid extraction process is carried out within a preferred pressure range of from about 100 to about 500 bar.
[0025] In an eleventh embodiment of the present invention according to the first through eighth embodiments above, the supercritical fluid extraction process is carried out within a preferred pressure range of from about 400 to about 500 bar.
[0026] In a twelfth embodiment of the present invention according to the first through eleventh embodiments above, the supercritical fluid extraction process is carried out within a time period of from 0 to 24 hours.
[0027] In a thirteenth embodiment of the present invention according to the first through eleventh embodiments above, the supercritical fluid extraction process is carried out within a time period of from 2 to 15 hours.
[0028] In a fourteenth embodiment of the present invention according to the first through eleventh embodiments above, the supercritical fluid extraction process is carried out within a time period of from 3 to 9 hours.
[0029] In a fifteenth embodiment according to the first through fourteenth embodiments above, the super critical fluid extraction process is carried out using a combination of carbon dioxide and an organic cosolvent modifier.
[0030] In an sixteenth embodiment of the present invention according to the fifteenth embodiment above, the organic cosolvent modifier is one or more selected from the group consisting of ethanol, methanol, 2-propanol, diethylether, ethyl acetate, chloroform, carbontetrachloride, acetonitrile, cyclohexane, acetone, acetic acid, nitromethane, dioxane, methylene chloride, hexane, pentane, acetylene, and pyridine.
[0031] In a seventeenth embodiment of the present invention, a supercritical fluid extraction process for extracting Delta-9-THC, Delta-8-THC and related pharmaceutically active compounds is provided, wherein the supercritical fluids used in said process comprise one or more selected from the group consisting of carbon dioxide, carbon monoxide, water, ethane, ammonia, nitrous oxide, fluoroform, and xenon.
[0032] In an eighteenth embodiment of the present invention according to the seventeenth embodiment above, the super critical fluid extraction process is carried out within an operating temperature range of from 31 to 120 ° C.
[0033] In a nineteenth embodiment of the present invention according to the seventeenth embodiment above, the supercritical fluid extraction process is carried out within an operating temperature range of from about 25-65° C.
[0034] In a twentieth embodiment of the present invention according to the seventeenth embodiment above, the supercritical fluid extraction process is carried out within an operating temperature range of from about 30-65° C.
[0035] In an twenty first embodiment of the present invention according to the seventeenth through twentieth embodiments above, the supercritical fluid extraction process is carried out within an operating temperature range of from about 35-45° C.
[0036] In a twenty second embodiment of the present invention according to the seventeenth through twenty first embodiments above, the supercritical fluid extraction process is carried out within a preferred pressure range of from about 70 to about 680 bar.
[0037] In a twenty third embodiment of the present invention according to the seventeenth through twenty first embodiments above, the supercritical fluid extraction process is carried out within a preferred pressure range of from about 100 to about 500 bar.
[0038] In a twenty fourth embodiment of the present invention according to the seventeenth through twenty first embodiments above, the supercritical fluid extraction process is carried out within a preferred pressure range of from about 400 to about 500 bar.
[0039] In a twenty fifth embodiment according to the seventeenth through twenty fourth embodiments above, the supercritical fluid extraction process is carried out within a time period of from 0 to 24 hours.
[0040] In a twenty sixth embodiment according to the seventeenth through twenty fourth embodiments above, the supercritical fluid extraction process is carried out within a time period of from 2 to 15 hours.
[0041] In a twenty seventh embodiment according to the seventeenth through twenty fourth embodiments above, the supercritical fluid extraction process is carried out within a time period of from 3 to 9 hours.
[0042] In a twenty eighth embodiment of the present invention, a method for decannabinization of marijuana is provided comprising subjecting marijuana plants to supercritical fluid extraction to remove delta-9-THC and related cannabinoids therefrom, wherein the delta-9-THC concentration of said marijuana is from about 0-0.5 wt. % after supercritical fluid extraction thereof.
[0043] In a twenty ninth embodiment of the present invention according to the twenty eighth embodiment above, the supercritical fluid extraction process for decannabinization of marijuana is carried out within a temperature range of from 25 to 65° C.
[0044] In a thirtieth embodiment of the present invention according to the twenty ninth embodiment above, the supercritical fluid extraction process is carried out at a pressure of from 400-500 bar.
[0045] In a thirty first embodiment of the present invention according to the twenty eighth embodiment above, a placebo marijuana cigarette is provided comprising the decannabinized marijuana produced by the process of the twenty eighth through thirtieth embodiments above, wherein the placebo marijuana cigarette has a concentration of Delta-9-THC and related cannabinoids of about 0 to about 0.5 wt %.
[0046] In a thirty second embodiment of the present invention according to the first through thirtieth embodiments above, the supercritical fluid extraction process is carried out at a flow rate of 20-50 ml/minute per 80 g of marijuana plant.
[0047] In a thirty third embodiment of the present invention according to the second through twenty seventh embodiments of the present invention, the organic cosolvent modifier comprises from greater than 0 to about 20 wt % of the supercritical fluid, based on the total amount of supercritical fluid.
[0048] Carbon dioxide is most preferred for the extraction process since it is nonflammable, nontoxic, less expensive than reagent grade liquid solvents, available in a high state of purity, and can be vented to the atmosphere or recycled without harm to the environment. Moreover, the SCF-CO 2 extractions can be performed under relatively mild conditions, thus, reducing the risks of thermal degradation and poor collection efficiencies of volatile analytes. Currently, CO 2 is recognized as safe, and is regulated by the U.S. Food and Drug Administration [CFR 21.184.1240 (C)] as a direct human food ingredient.
[0049] In the most preferred embodiment, the liquid CO 2 is used in a purified form, i.e., having a purity of from 95 to 100 wt % of CO 2 . Suitable cosolvents, which may be used in combination with the liquid CO 2 include ethanol, methanol, 2-propanol, ethyl acetate, acetonitrile, carbon tetrachloride, hexane, cyclohexane, and other nonpolar and semipolar solvents in an amount of from about 0 to 20 wt % of the total wt. of liquid supercritical fluid being used.
[0050] In a preferred embodiment, liquid CO 2 is used in the supercritical extraction process of Delta-9-Tetrahydrocannabinol and Delta-8-Tetrahydrocannabinol and other cannabinoids at temperatures ranging from 25° C. to 65° C., more preferably from 30 to 65° C., most preferably from 35 to 45° C. The supercritical extraction process is carried out at pressures ranging from about 70 to 550 bar, more preferably from 100 to 500 bar and most preferably from 400 to 500 bar.
[0051] According to the present invention, marijuana plant material is maintained in contact with the supercritical liquid CO 2 under the above temperature and pressure conditions for a period of from about 0 to 24 hours, preferably from about 2 to about 15 hours, more preferably from about 3 to about 9 hours, so as to facilitate the desired amount of removal of the cannabinoids from the marijuana plant material.
DETAILED DESCRIPTION OF THE INVENTION
[0052] The present invention provides a method of extraction of pharmaceutically active compounds from natural resources (such as marijuana plants) and use of the extracted compounds, either pure or mixture, for pharmaceutical dosage forms. The processed matrix (marijuana subjected to supercritical fluid extraction of the present invention) with defined strengths of active(s) ingredients, single compound or mixture of compounds, can be used for making delivery devices, such as marijuana cigarettes, with specific, known concentrations of Delta-9-THC and related pharmaceutically active compounds.
[0053] The extraction process of the present invention is carried out using supercritical fluid, preferably liquid CO 2 , either alone or in combination with other cosolvents, so as to retain the natural properties of the marijuana plant material.
[0054] In the most preferred embodiment, the liquid CO 2 is used in a purified form, i.e., having a purity of from 95 to 100 wt % of CO 2 . Suitable organic cosolvent modifiers, which may be used in combination with the liquid CO 2 include ethanol, methanol, 2-propanol, ethyl acetate, acetonitrile, carbon tetrachloride, hexane, cyclohexane, and other nonpolar and semipolar solvents. These cosolvents are present in an amount of from about 0 to about 20 wt % of the total wt. of liquid supercritical fluid being used. In certain instances, the use of a cosolvent may be advantageous for the purpose of selectivity, ease of extraction and shorter required extraction times. However, where volatile organic cosolvents are used, this may present an environmental problem and additional expense in insuring there is little or no escape of the organic cosolvents into the atmosphere.
[0055] In a preferred embodiment, liquid CO 2 is used in the supercritical extraction process of Delta-9-Tetrahydrocannabinol and Delta-8-Tetrahydrocannabinol and other cannibinoids at temperatures ranging from 25° C. to 65° C., more preferably from 30 to 65° C., most preferably from 35 to 45° C. The supercritical extraction process is carried out at pressures ranging from about 70 to 680 bar, more preferably from 100 to 500 bar and most preferably from 400 to 500 bar.
[0056] According to the present invention, marijuana plant material is maintained in contact with the supercritical liquid CO 2 under the above temperature and pressure conditions for a period of from about 0 to 24 hours, preferably from about 2 to about 15 hours, more preferably from about 3 to about 9 hours, so as to facilitate the desired amount of removal of the cannabinoids from the marijuana plant material.
[0057] The addition of an organic cosolvent modifier, as called for in the eighth embodiment, serves to increase fluid polarity, rather than alternate fluids such as propane, butane, and isobutane. However, it is within the scope of the invention to employ preferred supercritical fluids of carbon dioxide, carbon monoxide, water, ethane, ammonia, nitrous oxide, fluoroform, and xenon for the extraction of cannabinoids from marijuana plant materials.
[0058] In a preferred embodiment, the supercritical extraction process using liquid CO 2 is carried out in combination with a cosolvent comprising one or more of ethanol, methanol, 2-propanol, ethyl acetate, acetonitrile, carbon tetrachloride, hexane, cyclohexane, and other nonpolar and semipolar solvents, wherein the cosolvent can constitute from about 0 to 20 wt % of the total supercritical fluid used in the extraction. When a cosolvent of nonpolar and semipolar in nature is used with liquid CO 2 , the process is preferably carried out at a temperature range from about 30° C. to about 40° C., and at a pressure of from about 100 bar to about 400 bar, for a period of from about 3 to 7 hours.
[0059] During the extraction of cannabinoids from marijuana plant material, it is preferred that the supercritical fluid pass into contact with the plant material at a flow rate of from about 20 to 50 ml/min based on 80 gms of marijuana plant material being processed.
[0060] To increase the rate of extraction of the cannabinoids from the marijuana plant material, the flow rate of the supercritical fluid can be increased, as well as the residence time of the marijuana plant material in contact with the supercritical fluid.
[0061] The preferred solvent, liquid carbon dioxide, used in the SCFE process is environmentally safe and does not leave any residues. A small proportion of organic cosolvents addition for decannabinization of marijuana by SCFE will also remove the active ingredients under these mild operating conditions. Different process conditions may yield marijuana extracts with different amounts of THC.
[0062] Low density SF—CO 2 has the polarity of hexane. However, SF polarity increases with density, especially near the critical point. At its highest density, SF—CO 2 resembles the polarity of solvents such as toluene, benzene, and ether. In the supercritical state, CO 2 is at its critical temperature (31.3° C.) and is in its gaseous phase under high pressure (70-1500 bar).
[0063] According to the present invention, decannabinization of marijuana plant parts can be achieved under relatively mild conditions, and the processed marijuana unexpectedly retains its appearance/color and texture, irrespective of process conditions. The repeatability of this extraction process has also been demonstrated to remove delta-9-tetrahydrocannabinol present in the marijuana to a content of ˜0-0.5 wt. % starting from as high as 3.4 wt. %.
[0064] In another embodiment, cigarette machines can be easily modified to suit the handling of marijuana plant parts to produce marijuana cigarettes similar to commercial grade (e.g. tobacco) cigarettes. Placebo cigarettes can also be produced using SCFE treated marijuana. Applicants have successfully scaled up the SCFE process for amounts of marijuana from ˜25 g to ˜80 g.
[0065] Smoking of both untreated marijuana cigarettes and SCFE treated marijuana cigarettes were carried out successfully to determine the THC delivered from such device. Condensates taken from the cigarettes tested were analyzed by gas chromatography. Spiking of the placebo cigarettes with standardized THC content can be used to produce cigarettes having different strengths. Thus, according to the present invention, titrated cigarettes of different strengths can be produced which are excellent for clinical studies. The present invention leads to ready availability of an alternate natural source of THC to the synthetic sources. The selectively extracted compounds or mixture of compounds can be administered through different delivery devices for treatment of patients with severe ailments.
TEST EXAMPLES
Notes for all Tables
[0066] Concentration refers to the amount of delta-9-THC present in a unit volume of the analytical sample(s) prepared from either untreated or SCF treated marijuana or the SCF marijuana extract. For instance, C-00-001 is virgin marijuana, which was analyzed to estimate the amount (% w/w) of delta-9-THC present in marijuana. The concentration was measured by Gas Chromatography (GC). THC can also be analyzed by HPLC and other analytical techniques. The remaining marijuana samples are SCF-treated and extracts obtained therefrom.
[0067] % Delta-9-THC, refers to the amount of delta-9-THC present in a particular material, i.e. either the virgin marijuana or SCF-treated marijuana or SCF marijuana extract. These values are calculated based on the concentration observed in the analytical samples. Avg. % of delta-9-THC, is the sum of all (%) values of delta-9-THC divided by the total number of samples analyzed from a particular material.
Example 1
[0068] A small quantity (25 g) of marijuana plant material was obtained, so as to subject same to supercritical fluid (SCF) extraction, and started with random extraction conditions.
[0069] Initially, two samples of a quantity of virgin (natural, unextracted) marijuana (designated C-00-001 in Tables 1-3) was analyzed using gas chromatography to determine the amount of delta-9-THC therein. As shown in Table 1, it was determined that Lot # C-00-001 of virgin marijuana contained an average of 2.76% delta-9-THC, based on weight.
[0070] Then, a first sample of the virgin marijuana was subjected to SCF extraction under 150 bar pressure, with a flow rate of liquid CO 2 of 20 g/min, at 58° C. bath temperature, for a period of 4 hours, and a first analytical sample was obtained. A second sample of the virgin marijuana was subjected to SCF extraction as above, and a second analytical sample obtained. The first and second analytical samples were then analyzed using gas chromatography (GC) to determine the concentration of delta-9-THC present in the marijuana after extraction of delta-9-THC therefrom using the process above. The results of these GC measurements are shown in Table 1 below, labeled as “C-00-00”, which show that the virgin marijuana has an avg. % delta-9-THC of 1.88%.
[0071] The extracts obtained from the supercritical fluid extraction of the first and second samples above were then analyzed using GC analysis, to determine the amount of delta-9-THC present in the extracts. The results of these analyses are shown in Table 1. As shown below, approximately 30% of the total amount of delta-9-THC present in the sample was removed from the plant material, i.e., only about one-third of the delta-9-THC was extracted from the plant parts. This is reflected in the extract analysis (shown in Table 1).
TABLE 1 Delta-9-THC (Analysis (Lot #001101) Sample Concentration % Delta-9- Avg. % Delta- Lot # Weight (mg) (ug/mL) THC 9-THC C-00-001 97.4 920.90 2.84 2.76 100.1 895.57 2.68 001101 101.1 597.86 1.77 1.88 SCFE 98.9 655.3 1.99 Marijuana 001101 23.0 840.70 36.55 36.74 Extract 17.2 635.11 36.93
Example 2
[0072] A first sample of marijuana was taken from Lot # C-00-001, consisting of a marijuana leaf (designated “M. Leaf” in Table 2 below), and a second sample was taken from Lot # C-00-001, consisting of crushed marijuana leaves (designated “M. Leaf Crushed”).
[0073] Each of said samples above was analyzed using GC analysis, and the concentration in wt. % of delta-9-THC in the samples was determined. The results of these analyses is shown in Table 2 below (designated as “C-00-001, M. Leaf” and “C-00-001 M. Leaf Crushed”, respectively), where it can be seen that the virgin marijuana has a concentration of as much as 3.4 wt. %.
[0074] Then, two samples of the extracted marijuana plant material from the first and second analytical samples obtained above (from Lot # 001101 shown above) was then prepared, the first sample consisting of marijuana leaves (designated “M. Leaf” in Table 2) and the second sample consisting of crushed marijuana (designated “Marijuana Crushed” in Table 2). Each of these samples was then re-extracted with liquid CO 2 under a pressure of 400 bar at a 50 g/min flow rate for a period of 5 hours to obtain a third and fourth analytical sample (designated as “001102, SCFE Marijuana (M. Leaf)” and “001102, SCFE Marijuana Crushed”, respectively).
[0075] After re-extraction of the third and fourth samples, as described above, GC analysis was carried out to determine the concentration of delta-9-THC present in the sample. As shown in Table 2 below, this process reduced the delta-9-THC in the sample from 3.11 wt. % to 0.15 wt. %, and 0.21 wt. % from 3.39 wt. %, respectively.
[0076] In addition, GC analysis was carried out on each of the extracts (both designated as “001102, M. SCFE Extract) obtained in the re-extraction of the third and fourth samples above. The results of these analyses are shown in Table 2 below:
TABLE 2 Delta-9-THC Analysis (Lot #001102) Sample Concentration % Delta-9- Avg. % Delta- Lot # Weight (mg) (ug/mL) THC 9-THC 001102, 95.1 46.88 0.15 0.15 SCFE Marijuana (M. leaf) 001102, 92.6 66.26 0.21 0.21 SCFE Marijuana Crushed 001102, 18.1 788.32 43.55 47.22 M. SCFE 18.3 931.26 50.89 Extract C-00-001, 102.7 1099.30 3.11 3.11 M. Leaf C-00-001 97.2 1135.87 3.39 3.39 M. Leaf Crushed
Example 3
[0077] Another batch (Lot #001104) of 25 g of marijuana was obtained, 2 samples taken therefrom, and the samples subjected to supercritical fluid extraction having the following conditions: 30 g/min flow rate with liquid CO2 under 450 bar at 62° C. bath temperature for 6 hours. Then, these two samples (both designated as “SCFE Marijuana” in Table 3 below) were subjected to GC analysis to determine the concentration of delta-9-THC therein, the results of these analyses shown in Table 3 below. As shown, the above SCF extraction conditions resulted in an improved reduction of delta-9-THC concentration of from 3.4% to 0.1%.
TABLE 3 Delta-9-THC Analysis (Lot #001104) Sample Concentration % Delta-9- Avg. % Delta- Sample Weight (mg) (ug/mL) THC 9-THC SCFE 95.8 38.10 0.12 0.12 Marijuana 94.6 38.05 0.12 SCFE M. 17.3 668.75 38.66 38.24 Extract 26.7 1009.68 37.82
Example 4
[0078] Another batch of virgin marijuana, containing about 25 g of marijuana, was obtained, and 6 samples prepared therefrom (designated as “Sample Number” 1-6 in Table 4). Each of these samples was then processed by SCFE under different pressures, temperature, and time. (100 bar, 32 C., 20 g/min flow for 1 hour; 200 bar with the same conditions as before; 300 bar under the same conditions as before; 400 bar same conditions as before; 500 bar for 5 hours at 59 C. bath temperature) temperatures and time conditions.
[0079] This attempt lead to the reduction of delta-9-THC to 0.49%. The delta-9-THC present in the individual extracts varied from ˜20% to ˜46%.
Example 5
[0080] Another batch of 25 g of marijuana (designated as Lot # 001201R&D) was obtained, several samples prepared therefrom, and the samples processed using SCF extraction under different conditions of pressures of 72 (I set), 400 (II set), and 400(III set) bar, at a temperature of 31 (I), 31(II), and 60(III) ° C. for a period of 3.5 (I), 4.0 (II), and 2.5 (III) hours under a flow rate of 20 (I), 20 (II) and 30(III) g/min, respectively. The processed samples were then analyzed using GC analysis, the results thereof confirming that the process of decannabinization was repeatable, and the extent of delta-9-THC reduction depends upon the processing conditions.
[0081] The data for the lot #001201R&D is presented in Table 4 below. Different SCFE extracts obtained from marijuana utilizing different processing conditions exhibited a ˜20 to ˜46% reduction of delta-9-THC concentration. All these samples were analyzed by Gas chromatography.
TABLE 4 Delta -9- THC Analysis (Lot # 001201R&D) Sample Sample Weight Concentration % Avg. % Delta- Sample Number (mg) (ug/mL) Delta-9-THC 9-THC Marijuana 1 95.5 75.33 0.24 0.23 2 96.1 71.55 0.22 3 104.5 81.49 0.23 4 101.4 74.33 0.22 5 94.3 59.32 0.19 6 102.6 87.09 0.25 Extract I A 22.5 952.59 42.34 41.73 Powder B 16.5 678.65 41.13 Extract I A 18.2 613.48 33.71 33.36 Sticky B 20.7 683.46 33.02 Extract III A 20.9 598.61 28.64 28.62 B 22.9 654.72 28.59
SCALE UP OF SCF EXTRACTION
Example 6
[0082] A scaled up batch of ˜80 g of marijuana obtained from Lot #R010101, samples prepared therefrom and said samples processed using SCF under different conditions of a pressures of 72 (I set), 400 (II set), and 400 (III set) bar, at a temperature of 31 (I), 31 (II), and 51 (III) ° C. for a period of 0.5 (I), 4.0 (II), and 5 (III) hours under a flow rate of 20 (I), 20 (II) and 30(III) g/min, respectively. The scale up SCF extraction process was conducted to establish the extraction efficiency on scale up batch levels.
[0083] Each of the samples was then subjected to GC analysis to determine the delta-9-THC concentration in the samples after SCF extraction of delta-p-THC. The results confirmed that the process of decannabinization is repeatable, and the extent of delta-9-THC reduction depends on the processing conditions. Data concerning each of the samples prepared from lot #R010101 is presented in Table 5 below. Different SCFE extracts obtained from the marijuana utilizing different processing conditions exhibited about 8 to 40% reduction of delta-9-THC in the marijuana. All of these samples were analyzed by gas chromatography.
TABLE 5 Delta -9- THC Analysis (Lot # R010101) Sample Sample Concentration % Avg. % Delta- Sample Number Weight (mg) (ug/mL) Delta-9-THC 9-THC Marijuana 1 109.1 82.61 0.23 0.23 2 97.1 77.42 0.24 3 96.7 74.40 0.23 4 103.4 76.06 0.22 5 96.3 70.48 0.22 6 97.0 69.41 0.21 Extract 1 A 94.8 162.60 8.58 8.58 Extract 2 A 121.8 952.73 39.11 40.07 B 102.7 842.86 41.04 Extract 3 A 102.0 653.42 32.03 32.49 B 111.7 735.9 32.94
Example 7
[0084] Another scale up batch of about 80 g of marijuana was obtained (designated as Lot # R010200), samples prepared therefrom, and said samples subjected to SCF extraction under conditions similar to those in Example 6, with minor variations of a pressure of 72 (I set), 400 (II set), and 450 (III set) bar, at a temperature of 31 (I), 31 (II), and 45 (III) ° C. for a period of 1.0 (I), 4.0 (II), and 5 (III) hours under a flow rate of 20 (I), 20 (II) and 30(III) g/min, respectively. Each of the samples was then subjected to GC analysis, to determine the concentration of delta-9-THC therein after SCF extraction was carried out thereon. Test data for each of said samples is presented in Table 6 below. The data demonstrates that the process of the present invention is repeatable, but the efficiency did not improve further.
TABLE 5 Delta -9- THC Analysis (Lot # R010200) Sample Sample Concentration % Avg. % Delta- Sample Number Weight (mg) (ug/mL) Delta-9-THC 9-THC Marijuana 1 104.8 104.66 0.30 0.30 2 106.2 119.16 0.34 3 97.8 88.18 0.27 4 96.2 94.86 0.30 5 97.4 100.77 0.31 6 108.3 111.32 0.31 Extract 1 A 25.2 508.22 20.17 19.85 B 23.8 464.64 19.52 Extract 2 A 21.6 743.85 34.44 37.58 B 19.4 789.86 40.71 Extract 3 A 22.0 614.15 27.92 28.50 B 15.5 450.95 29.09
Example 8
[0085] The scaled up batch process illustrated in Example 7 above was repeated. However, the SCF extraction was carried out at an increased temperature of from 45 to 60° C. (in IIIrd set only). It was unexpectedly discovered that increasing the temperature to within this narrow range improved the extraction results, i.e., more delta-9-THC was removed from the sample, resulting in near complete removal of delta-9-THC from the marijuana plant parts. This data is illustrated in Table 7 below.
TABLE 7 Delta -9- THC Analysis (Lot # R010201) Sample Sample Concentration % Avg. % Delta- Sample Number Weight (mg) (ug/mL) Delta-9-THC 9-THC Marijuana 1 98.9 47.44 0.14 0.14 2 105.9 43.58 0.12 3 101.1 48.13 0.14 4 102.3 42.83 0.13 5 103.2 49.81 0.14 6 105.2 49.08 0.14 Extract 1 A 24.4 407.46 16.70 17.38 B 18.8 339.73 18.07 Extract 2 A 26.2 922.53 35.21 36.52 B 20.8 787.00 37.84 Extract 3 A 20.9 348.76 16.69 15.87 B 24.3 365.56 15.04
Example 9
[0086] Another scale up batch of marijuana was obtained (designated as Lot # R010201), samples prepared therefrom, and the SCF extraction process described in Example 8 repeated on large scale, with the elimination of one (I set) set of conditions. More specifically, the samples were processed under two sets of conditions, i.e., of pressures of 400 (I set) and 450 (II set) bar, at temperatures of 34 (I) and 50 (II) ° C., and for periods of 4.0 (I) and 7.0 (II) hours under flow rates of 20 (I) and 30(II) g/min, respectively. Each of the samples was then analyzed using gas chromatography, to determine the concentration of the delta-9-THC present in each of the samples after SCF extraction was carried out theron.
[0087] The results of these tests are presented in Table 8 below. These test results show that the SCF extraction of marijuana plant parts is feasible, and the marijuana retains its original color for making placebo cigarettes, or for spiking placebo cigarettes.
TABLE 8 Delta -9- THC Analysis (Lot # R010202) Sample Sample Concentration % Avg. % Delta- Sample Number Weight (mg) (ug/mL) Delta-9-THC 9-THC Marijuana 1 99.7 48.56 0.15 0.14 2 103.4 48.46 0.14 3 110.7 46.39 0.13 4 104.4 52.78 0.15 5 103.3 48.87 0.14 6 99.2 51.75 0.16 Extract 1 A 22.6 686.77 30.39 34.18 B 20.0 759.52 37.98 Extract 2 A 23.8 508.86 21.38 20.99 B 22.8 469.45 20.59
Example 10
[0088] Another batch of virgin marijuana was obtained (designated as Lot # R020408, consisting of about 25 g of marijuana), four samples prepared therefrom, and said samples processed by SCF extraction under the following conditions: a pressure of 450 bar, a temperature of 55° C., and a flow rate of 30 g liquid carbon dioxide/min for 7 hours. The processed material (i.e., marijuana subjected to SCF extraction) was then re-extracted with differing amounts of ethanol (10, 20, 30 and 40 ml ethanol, respectively) under a pressure 350 bar, a temperature of 50° C., and a flow rate of 30 g of liquid carbon dioxide/min at four different times for one hour each. As mentioned above, the amount of ethanol used was 10, 20, 30 to 40 ml for the four different process cycles, respectively.
[0089] The four SCFE marijuana samples were then analyzed by GC. The results showed that the Delta-9-THC in marijuana was removed to the extent of 0.07%. i.e., the re-extracted samples were “decannabinized marijuana” as desired for use in placebo marijuana cigarettes.
[0090] As mentioned above, for the analysis of delta-9-THC extracted from marijuana plant parts and SCF extracts, gas chromatography was used in all cases. Marijuana plant extraction was carried out with organic solvent systems for sample analysis. In the analysis ˜20-100 mg of marijuana, or its extract, was introduced into a test tube. 10 mL of an extraction solvent (90:10 methanol:chloroform) containing 1000 g/mL of internal standard (4-androstene-3,17-dione) was then added to the marijuana or marijuana extract. The solution was then sonicated for ˜10 minutes to break up the lumps, and centrifuged to separate the suspension from the supernatant. The supernatant was then subjected to GC analysis.
MARIJUANA CIGARETTE PREPARATION
Example 11
[0091] A first blend of about 300 g of untreated marijuana plant parts was humidified to raise the moisture content of the marijuana by sprinkling water and leaving the marijuana overnight to absorb the water and produce humidified marijuana. The humidified marijuana was then used for rolling cigarettes using a cigarette machine, which was modified to suit the handling of marijuana plant parts. The process resulted in a high quality of marijuana cigarettes suitable for smoking experiments.
[0092] Similarly, a second blend of SCF-extracted marijuana (i.e., so-called “decannabinized marijuana” having a low delta-9-THC concentration) pooled from different batches of extraction formed one blend was produced. This blend was utilized to make marijuana cigarettes upon humidification. A good quality of cigarettes was obtained from the SCF processed marijuana. The quality of cigarettes was verified by the Quality Control Department of Murty Pharmaceuticals, Inc. (MPI).
FTC SMOKE TESTING OF CIGARETTES
Example 12
[0093] The marijuana cigarettes made from both untreated and SCF treated marijuana were used for initial smoke testing (FTC). It was found that the cigarettes made at MPI were of high quality in terms of handling, testing, and appearance. Importantly, the THC content present in the placebo cigarettes produced by MPI was negligible. These placebo cigarettes are important for use as a control in marijuana smoke testing.
[0094] As demonstrated by the test results shown in the above Examples, SCF extraction of marijuana plant parts for the removal of THC proved to be feasible and repeatable under mild and environmentally acceptable conditions. Selective extraction was achieved, by varying the processing conditions, such as pressure, temperature and duration of the extraction process. | A process for supercritical fluid extraction of delta-9-tetrahydrocannabinol (delta-9-THC), delta-8-THC, cannabinoids or other medicinal value compounds from marijuana and other plants. Preferably, the extraction is carried out with a solvent of liquid carbon dioxide alone, or in combination with a solvent of ethanol, methanol, isopropanol, and other nonpolar/semipolar solvents at a temperature and pressure to maintain the solvents in a supercritical state. The extraction process is preferably carried out for a period of from 0 to 9 hours. The extraction process conditions result in different strengths of extracted marijuana and selective isolation of extracted compounds or mixtures of compounds. The processed marijuana leaves or other parts of the marijuana plant can be used in the manufacture of different strengths of cigarettes for the delivery of delta-9-THC or other related compounds, or as adjuvant drugs for antiinflammatory and analgesic treatment, especially for chronic and terminal pain, neuropathic pain symptoms in humans, and in animals. Further, spiking methods can be used to make cigarettes of different strengths containing delta-9-THC or other related compounds, either synthetic or natural. Placebo cigarettes can also be prepared with pharmacologically negligible quantities of an active compound. The isolated compounds, or mixture of isolated compounds and adjuvants, of the extracted compounds can be used for the treatment of the above mentioned symptoms, either through cigarettes or by other suitable delivery systems. | 2 |
BACKGROUND OF THE INVENTION
1. Filed of the Invention
The present invention relates to a dispenser of a detergent supply apparatus for a washing machine, more particularly, which is capable of dispensing washing water fed from a water supplier, by being widely scattered over a detergent container. With that, washing water and detergent can be efficiently mixed, and be supplied to a tub of the washing machine.
2. Description of the Related Art
FIG. 1 shows a detergent supply apparatus of a washing machine based on the prior art, and FIG. 2 shows a dispenser based on the prior art.
The detergent supply apparatus of the washing machine comprises a detergent container 2 which stores detergent, a housing 1 mounted in a cabinet assembly 8 , and a dispenser 3 installed in a top portion of the housing 1 to dispense washing water supplied from a water supplier to the detergent container 2 (see FIG. 1 ).
The detergent container 2 which stores detergent, bleach or fabric softner is inserted into the housing 1 to move forward. Detergent, bleach or fabric softner in the detergent container 2 is diluted by washing water supplied from the dispenser 3 , and is supplied to a tub of the washing machine.
The dispenser 3 comprises a top cover 5 and a bottom cover 4 . Those edges are assembled by melting bond. Washing water flowed in the dispenser 3 is supplied to the detergent container 2 through a plurality of holes 6 configured on the bottom cover 4 (see FIG. 2 )
A water passage 9 is configured in the bottom cover 4 due to an upwardly protruded rib 7 that helps washing water from the water supplier to be efficiently dispensed and be dropped toward the detergent container 2 . The water passage 9 is made to turn around several times, so as to take up much space of the bottom cover 4 .
The water passage 9 includes an inlet water passage 10 where washing water enters the dispenser 3 and goes ahead without changing its direction, and a turning water passage 12 where washing water through the inlet water passage 10 changes its direction and flows.
In case a plurality of turning water passages 12 are configured in the water passage 9 , if the pressure of washing water through the inlet water passage 10 is not that high, the water pressure gets lowered while washing water moves. It results that washing water does not smoothly flow up to an end water passage 14 situated in an end of the water passage 9 .
After all, the conventional dispenser for the washing machine has a problem that washing water is not dispensed to the end water passage 14 , thus, detergent, fabric softner or bleach stored in the detergent container 2 does not get dissolved and diluted well.
SUMMARY OF THE INVENTION
An aspect of the present invention fulfills the foregoing needs by providing a dispenser which widely scatters washing water over an overall detergent container.
The dispenser for a washing machine having a detergent supply apparatus comprises a dispense chamber which has a plurality of holes on its bottom to supply washing water to the detergent container, and a main water passage which makes washing water entering the dispense chamber spread out the dispense chamber. The main water passage includes an inlet water passage where washing water flows into the dispense chamber and flows toward an end of the dispense chamber, a turning water passage where washing water converts its course, and an end water passage positioned in an end of the main water passage. A subsidiary water passage is configured in the inlet water passage, where some quantity of washing water flowing therein is delivered to another water passage.
The subsidiary water passage is placed between the inlet water passage and the end water passage, or between the inlet water passage and the turning water passage.
The main water passage is formed by a protruded rib and the subsidiary water passage, which means a slit, is formed as the rib is cut by predetermined distance.
The slit is inclined along a direction of washing water running the inlet water passage.
The dispense chamber includes a main dispense chamber which supplies washing water to a main detergent chamber, and a subsidiary dispense chamber which supplies washing water to a preliminary detergent chamber. The slit is only in the main detergent chamber.
The slit is formed in the rib located between the inlet water passage and the turning water passage. A guide rib is formed in order that washing water through the slit flows to the turning water passage.
The dispenser for the washing machine has the slit of the subsidiary water passage between the inlet water passage and the end water passage. Washing water through the slit is directly supplied throughout the main water passage, from the inlet water passage to the end water passage. Ultimately, washing water can be widely scattered over the detergent container.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is an exploded perspective view of a washing machine having a detergent supply apparatus, according to the prior art.
FIG. 2 is a perspective view of a dispenser, according to the prior art.
FIG. 3 is an exploded perspective view of a drum-type washing machine having the dispenser of the detergent supply apparatus, according to the embodiment of the present invention.
FIG. 4 is an exploded perspective view of the detergent supply apparatus having the dispenser, according to the embodiment of the present invention.
FIG. 5 is an exploded perspective view of the dispenser, according to the 1 st embodiment of the present invention.
FIG. 6 is a plane view of a bottom cover of the dispenser illustrated in FIG. 5 .
FIG. 7 is an exploded view of the dispenser, according to the 2 nd embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
FIG. 3 shows a drum-type washing machine having a dispenser of a detergent supply apparatus, according to the embodiment of the present invention. FIG. 4 shows the detergent supply apparatus having the dispenser, according to the embodiment of the present invention. FIG. 5 shows the dispenser, according to the 1 st embodiment of the present invention. And, FIG. 6 shows a bottom cover of the dispenser, according to the 1 st embodiment of the present invention.
As seen in FIG. 3 , the drum-type washing machine having the dispenser based on the embodiment of the present invention comprises a cabinet assembly 20 which defines an outer appearance of the washing machine, a tub 30 provided in the cabinet assembly 20 to contain washing water, a drum 40 rotatably set in the tub 30 , a motor (not shown) connected to the drum 40 to drive the drum 40 rotating, and the detergent supply apparatus 50 installed in a top end of the cabinet assembly 20 .
The cabinet assembly 20 includes a cabinet 22 which makes both sides and a rear of the drum-type washing machine, a front cover 24 mounted on a front of the cabinet 22 , and a top cover 26 mounted on a top of the cabinet 22 .
A water supply valve 28 and a water supply hose 29 are set in an inner side of the cabinet 22 , so as to supply washing water to the detergent supply apparatus 50 .
The detergent supply apparatus 50 , as referring to FIG. 3 or 4 , comprises a housing 52 located in the cabinet 22 , the dispenser 60 located in a top of the housing 52 and connected to the water supply hose 29 to receive washing water, and a detergent container 54 movably set in the housing 52 .
The detergent container 54 which stores detergent, fabric softner or bleach is partitioned into a main detergent storing section 541 for main washing, and a preliminary detergent storing section 542 for preliminary washing.
Washing water got through the housing 52 is supplied to the tub 30 by a bellow hose 55 .
The dispenser, as referring to FIG. 4 or 5 , comprises a top cover 62 and a bottom cover 64 . The bottom cover 64 includes a tube 61 which meets the water supply hose 29 . As the top cover 62 and the bottom cover 64 are assembled by melting bond, washing water fed from the tube 61 does not outflow through a crack between those covers.
A water passage is configured in at least one of the covers, where water through the tube 61 is dispersed over the detergent container 54 and is dropped. As an example, the water passage configured in the bottom cover 64 is described in the present invention.
The structure of the water passage configured in the bottom cover 64 is described below.
The bottom cover 64 is partitioned into a main dispense chamber D 1 which supplies washing water to the main detergent storing section 541 , and a preliminary dispense chamber D 2 which supplies washing water to the preliminary detergent storing section 542 . The main dispense chamber D 1 and the preliminary dispense chamber D 2 are segmented in the shape of a square by an upwardly protruded rib 90 . A plurality of holes 65 is perforated on the dispense chambers, which makes washing water fallen to the detergent chambers 541 , 542 .
The dispense chambers D 1 , D 2 include a main water passage 70 where washing water through the tube 61 is scattered over the overall dispense chambers D 1 , D 2 and flows, and a subsidiary water passage 80 located in an end of the main water passage 70 , where washing water is less supplied, to diverge washing water through the main water passage 70 and supply.
The main water passage 70 includes an inlet water passage 72 where washing water supplied from the tube 61 flows in the dispense chambers D 1 , D 2 and flows forward, at least one turning water passage 74 where washing water moved along the main water passage 70 changes its course, and an end water passage 76 located in the end of the main water passage, where washing water passing through the turning water passage 74 arrives last.
The main water passage 70 is configured by an upwardly protruded rib 78 on the bottom cover 64 .
The subsidiary water passage 80 is configured by a slit as the rib 78 that provides the main water passage 70 is cut by predetermined distance, and is placed in the rib 78 that makes the inlet water passage 72 out of the main water passage 70 .
The slit of the subsidiary water passage 80 , as shown in FIGS. 5 and 6 , is inclined toward a direction of washing water running the inlet water passage 72 . The slit penetrates the inlet water passage 72 and the end water passage 76 .
As illustrated in FIG. 6 , the subsidiary water passage may be configured in both ribs 781 , 782 which make the inlet water passage 72 , facing each other like a slit 81 , or be configured in one end of the rib 782 like a slit 82 .
The slit is only configured in the main dispense chamber D 1 having relatively long length of the main water passage 70 , and may not be configured in the subsidiary dispense chamber D 2 having relatively short length of the main water passage 70 .
It is appreciated that the subsidiary water passage in the main dispense chamber D 1 may be optionally one slit 82 at a front portion of the inlet water passage 72 , or a couple of the slits 81 at a back portion of the inlet water passage, facing each other.
One slit 82 prevents that washing water excessively flows out from the inlet water passage 72 to the end water passage 76 . A couple of slits 81 supply an equal amount of washing water to a top side and a bottom side of the end water passage 76 .
A flowing process with respect to washing water based on the 1 st embodiment of the present invention will be explained in greater detail, referring to FIG. 3 or 6 .
Washing water fed from the water supply valve 28 and the water supply hose 29 moves to the inlet water passage 72 through the tube 61 and flows therein. Then, some quantity of washing water transfers to the end water passage 76 by the subsidiary water passage 80 , on the way that washing water keeps straight through the inlet water passage 72 .
Washing water which moves straight without diverging in the subsidiary water passage 80 changes its direction at an angle of 180 degrees by the turning water passage 74 . It flows to the end water passage 76 or another turning water passage 74 . Washing water got in the dispense chambers D 1 , D 2 runs along the water passage, and drops into the detergent container through the holes 65 on a bottom of the dispenser.
Washing water flowed in the end water passage 76 through the subsidiary water passage 80 collides with washing water through the turning water passage 74 , and drops through the holes 65 .
FIG. 7 shows the dispenser, according to the 2 nd embodiment of the present invention.
The subsidiary water passages 84 , 85 based on the 2 nd embodiment of the present invention make some quantity of washing water running the inlet water passage 72 supply to at least one of the turning water passages 92 , 93 .
The subsidiary water passages 84 , 85 are configured in the rib 78 that makes the main water passage 72 , so as to diverge washing water running the inlet water passage 72 and flow to the 2 nd , 3 rd turning water passages 92 , 93 .
The subsidiary water passages 84 , 85 are formed with the slit in the same manner as the 1 st embodiment of the present invention.
A guide rib 783 is formed around the slit 85 , which makes washing water through the slit 85 flow in the 2 nd turning water passage 92 , without directly flowing in the end water passage 76 .
As described above, the present invention provides the dispenser having the main water passage 70 with a large quantity of washing water, and the slit of the subsidiary water passage 80 between space from the end water passage 76 or from the turning water passage 74 with a small quantity of washing water. The slit makes washing water running the main water passage diverged, and directly supplies to the end water passage 76 where washing water has not been sufficiently supplied. Washing water can be widely scattered over the bottom cover 64 of the dispenser.
Washing water equally drops through the holes 65 on the bottom cover 64 of the dispenser. Detergent in the detergent container 54 can be quickly dissolved and the solubility can be improved.
The subsidiary water passage 80 of the dispenser is inclined toward the direction of washing water. Washing water running the main water passage can be effectively diverged to the end water passage.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. | The present invention provides a dispenser which evenly dispenses washing water to a detergent container. Within the dispenser, a slit of a subsidiary water passage is configured in a rib located between an inlet water passage where washing water enters the dispenser and an end water passage distant from the inlet water passage by the farthest. Some quantity of washing water running the inlet water passage is diverged and moves to the end water passage where washing water has been insufficiently supplied. Hereby, washing water is equally scattered over the dispenser and drops into the detergent container. The dissolving power can be much more enhanced. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates to improved pharmaceutical compositions of hydrophobic drugs which have enhanced solubility and to a method for preparing such compositions.
BACKGROUND TO THE INVENTION
[0002] One of the biggest challenges facing the pharmaceutical and biotechnology industries at present is the poor solubility of new and established chemical entities. It is estimated that up to 90% on new molecular entities and 40% of existing compounds can be categorised as BCS class II or IV, which means that they show poor and variable oral bioavailability in vivo (Ref 1). Due to their low dissolution rate and poor bioavailability, hydrophobic drugs are challenging to administer and formulate.
[0003] Hydrophobic drugs may also suffer from food effects, erratic absorption and large variability in inter- and intra-patient dose response. While microemulsion preconcentrates have been used in the art to overcome some of these difficulties, they are often administered in a concentrated liquid or semi-solid form either as a drink solution or in a monolithic soft or hard elastic capsule. As is well known in the art, monolithic dosage forms have several disadvantages including dose dumping, susceptibility to food intake, local irritation, variable gastric emptying and transit. In addition, drink solutions are not as acceptable to patients, are difficult to store and may be dosed irregularly by a patient.
[0004] While numerous formulations of liquid emulsion pre-concentrates abound in the art, they pose a number of stability issues including leakage of fill from capsule during storage, dehydration of the capsule shell, retardation of capsule dissolution due to crosslinking of the shell or drug precipitation. Also, with liquids, solubilisation of the entire drug dose in a single capsule volume suitable for oral administration is sometimes not possible. High production costs, low portability and choice of available dosage forms are other disadvantages.
[0005] A multiparticulate solid microemulsion preconcentrate would overcome many of the above-described hurdles. However, whilst solid dispersions and emulsion preconcentrates have been explored for poorly soluble drugs, scale-up has proved to be a significant limitation in their development as a formulation tool.
[0006] In addition, there exists a need for patient-centric formulations to promote better treatment compliance. The multiparticulate format of the present invention allows individualised dosing and titration as opposed to the fixed dosing regimen of conventional dosage forms. Multiparticulates are easily swallowed and are therefore ideal for patients with swallowing difficulties (dysphagia) e.g. the elderly and children. Fenofibrate is a hydrophobic, lipid-regulating agent used in the treatment of adult endogenous hyperlipidaemia, hypercholesterolaemia and hypertriglyceridaemia. The chemical name for fenofibrate is 2-(4-(4-chlorobenzoyl)phenoxy)-2-methyl-propionate. The active metabolite of fenofibrate is its hydrolyzed acid derivative, fenofibric acid. Treatment with fenofibrate leads to reductions in total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, total triglycerifes and triglyceride rich lipoprotein. Furthermore, an increase in the level of high-density lipoprotein (so called good cholesterol) and apoproteins apoA-I and apoA-II is observed on treatment with fenofibrate.
[0007] Fenofibrate is currently marketed as tablets under the trade names Tricor™, Fenoglide® and Triglide® and as capsules under the trade names Antara® and Lipofen®.
[0008] Fenofibrate is poorly soluble in water and consequently has limited bioavailability. The drug has poor solubility in gastrointestinal fluid and consequently is poorly absorbed. Ibuprofen (iso-butyl-propanoic-phenolic acid) is a non-steroidal anti-inflammatory drug (NSAID) used for pain relief, fever reduction, and for reducing swelling. It has an antiplatelet effect, which is relatively mild and short-lived compared with aspirin or prescription antiplatelet drugs. In general, ibuprofen also has a vasodilation effect. Ibuprofen is available under a variety of trademarks, such as Motrin, Nurofen, Advil, and Nuprin.
[0009] Nonsteroidal anti-inflammatory drugs such as ibuprofen work by inhibiting the enzyme cyclooxygenase (COX), which converts arachidonic acid to prostaglandin H2 (PGH2). PGH 2 , in turn, is converted by other enzymes to several other prostaglandins (which are mediators of pain, inflammation, and fever) and to thromboxane A2 (which stimulates platelet aggregation, leading to the formation of blood clots).
[0010] Like aspirin and indomethacin, ibuprofen is a nonselective COX inhibitor, in that it inhibits two isoforms of cyclooxygenase, COX-1 and COX-2. The analgesic, antipyretic, and anti-inflammatory activity of NSAIDs appears to operate mainly through inhibition of COX-2, whereas inhibition of COX-1 would be responsible for unwanted effects on the gastrointestinal tract.
[0011] Ibuprofen is only very slightly soluble in water. Less than 1 mg of ibuprofen dissolves in 1 ml water (<1 mg/ml).
[0012] Gemfibrozil is an oral drug used to lower lipid levels. It belongs to a group of drugs known as fibrates. It is most commonly sold as the brand names, Lopid, Jezil and Gen-Fibro. Ii is an activator of Peroxisome proliferator-activated receptor-alpha (PPARα), a nuclear receptor that is involved in metabolism of carbohydrates and fats, as well as adipose tissue differentiation. This increase in the synthesis of lipoprotein lipase thereby increases the clearance of triglycerides and so lowers that lipid levels in the body. It has a solid ability in water of less than <1 mg/ml at 25° C.
[0013] Nabumetone is a non-steroidal anti-inflammatory drug, a 1-naphthaleneacetic acid derivative. It is available under numerous brand names, such as Relafen, Relifex, and Gambaran. It is used to treat pain or inflammation caused by arthritis or other inflammatory diseases and conditions like synovitis. Nabumetone works by reducing the effects of enzymes that cause pain and inflammation. It is practically insoluble in water. There are many other poorly soluble pharmaceutically active agents which could be formulated in accordance with the present invention. These include benzocaine, chlorambucil, cyclophosphamide, flurazepam, ketoprofen, lidocaine, nicorandil, oxprenolol, piribedil, pirprofen, suloctidil, tropinone, trimipramine, trimethadione, diethylcarbamazine, cyclandelate, quinine, scopolamine, promethazine, triprolidine, gemfibrozil, dinoprostone, etomidate, trimeprazine, isosorbide dinitrate, bleomycin, thioridazine, mitotane, chlorphenesin, allylestrenol, ethambutol, carisoprodol, benzocaine, maprotilin and ethotoin. The invention would also be suitable for use with new molecular entities that have poor solubility.
[0014] Bioavailability is the degree to which an active ingredient, after administration becomes available to the target tissue. Poor bioavailability poses significant problems in the development of pharmaceutical compositions. Active ingredients that are poorly soluble in aqueous media often have insufficient dissolution and consequently have poor bioavailability within an organism after oral administration. If solubility is low there may be incomplete and/or erratic absorption of the drug on either an intra-patient or inter-patient basis. In order to circumvent this disadvantage, the administration of multiple therapeutic doses is often necessary.
[0015] In recent years, focus in formulation laboratories for improving the bioavailability of hydrophobic pharmacologically active ingredients has been upon reducing particle size. The rate of dissolution of a particulate drug can be increased, by decreasing particle size, through an effective increase in surface area.
[0016] Considerable effort has been made to develop methods for controlling drug particle size in pharmaceutical compositions. For example, in order to improve the rate of dissolution of fenofibrate, a wide variety of formulation methods have been employed, including micronization of the active principle, addition of a surfactant and co-micronization of fenofibrate with a surfactant.
[0017] U.S. Pat. No. 4,961,890 to Boyer, describes fenofibrate granules, in which fenofibrate is micronized in order to increase its bioavailability. Each fenofibrate granule comprises an inert core, a layer based on fenofibrate and a protective outer layer. The crystalline fenofibrate particles are less than 30 μm in diameter. The binder used is a water soluble polymer, for example polyvinylpyrrolidine, and constitutes an inert water soluble matrix in which the micronized fenofibrate is suspended. The quantity of binder used is such that the amount of fenofibrate released after stirring in a galenical preparation for 1 hour is at least 65%. No examples quantifying specifically, the release of fenofibrate in aqueous media are provided.
[0018] In the prior art, the problem of water-insoluble pharmaceutically active substances has been addressed by formulating the actives as micron and sub-micron sized particles in water or as a suspension in an aqueous environment. However these particles tend to grow over time and it is difficult to remove water from them to convert them to solid dosage forms. Alternative solutions include formulation in non-aqueous media, or in biocompatible oils which are then dispersed in water using surfactants to produce oil-in-water emulsions, or the drugs may be dissolved in water-miscible organic solvents or in mixtures of oils and surfactants.
[0019] Other solutions to the problem include specific solutions for particular actives. U.S. Pat. No. 6,306,434 discloses a composition comprising cyclosporin which has low bioavailibility due to its poor aqueous solubility. The composition is a solid-state microemulsion which comprises a solidified product which consists essentially of a cyclosporin microemulsion dispersed in an enteric carrier. The carrier is typically an enteric polymer.
[0020] European patent No. 1,214,059 discloses a composition comprising water-insoluble biologically active substances dispersed in a non-aqueous carrier which comprises a non-aqueous medium in which the active is either not soluble or is poorly soluble, a surfactant which in turn comprises at least one phospholipid surfactant which is soluble in the medium, but at least a portion of which adsorbs to the surface of the drug particles, and up to 10% of at least one hydrophilic substance which provides a self-dispersing property to the composition.
[0021] U.S. Pat. No. 5,952,004 discloses a composition which comprises an oil-in-water emulsion which in turn comprises a discontinuous hydrophobic phase, a continuous aqueous hydrophilic phase and at least one surfactant selected from poloxamer 124, a polyglycolised glyceride, sorbitan laurate and polyoxyethylene (20) sorbitan monooleate, for dispersing the hydrophobic phase in the hydrophilic phase.
[0022] WO0016749 discloses a method for preparing novel galenic formulations of fenofibrate with improved bioavailability after oral administration consisting of (a) micronizing fenofibrate; (b) granulating the fenofibrate in the presence of a liquid medium comprising a surfactant, water and water-miscible alcohol; and (c) drying the resulting granular material.
[0023] In WO2004028506, pharmaceutical compositions of fenofibrate with high bioavailability after oral administration are disclosed. The immediate release fenofibrate composition comprises an inert hydro-insoluble carrier with at least one layer containing micronized fenofibrate, a hydrophilic polymer and a surfactant; and optionally one or several outer phases or layers.
[0024] Curtet et al. in U.S. Pat. No. 4,895,726 proposes improving the bioavailability of fenofibrate by co-micronizing it with a solid surfactant such as sodium lauryl-sulphate, wherein the mean particle size of said co-micronized mixture is less than 15 μm. The co-micronizate is then granulated by wet granulation in order to improve the flow capacities of the powder and to facilitate the transformation into gelatin capsules.
[0025] In U.S. Pat. No. 5,882,680, β-carotene is added to a middle chain length fatty acid (MCT); the resulting mixture is emulsified to produce a dispersion, which is subsequently homogenised to form a suspension. The suspension then enters a device for the manufacture of seamless capsules, namely a “Spherex” device (manufactured by Freund Industrial Co., Ltd.), the suspension is heated to 35° C. and forms an encapsulating liquid which is subsequently enveloped by an outer shell forming liquid at 70° C. composed of an aqueous solution of gelatin and sorbitol. The seamless capsule is formed when the encapsulating liquid is passed through the inner tube of series of coaxial tubes and simultaneously the outer shell liquid is passed through the outer tube of the coaxial tubing arrangement, the resulting droplets that form enter a hardening liquid of MCT cooled to 9° C.
[0026] Other efforts to improve the solubility of fenofibrate include producing drug particles with an effective particle size of less than about 2000nm (see U.S. Pat. Nos. 7,276,249 and 7,320,802). Other attempts to improve solubility involve use of a crystalline drug substance which has a non-cross-linked surface modifier adsorbed onto its surface which maintains an effective particle size of less than about 400nm (see U.S. Pat. No. 5,145,684).
[0027] Notwithstanding the state of the art there remains a need for alternative formulations for poorly soluble drugs to improve their bioavailability.
OBJECT OF THE INVENTION
[0028] It is an object of the invention to provide an improved formulation for poorly water soluble or water insoluble active substances, which has improved bioavailability. Accordingly, a further object is to provide a novel composition, comprising poorly water soluble or water insoluble actives which have enhanced dissolution and absorption profiles. A still further object is to provide a solid dosage form for poorly water-soluble and water insoluble active substances.
SUMMARY OF THE INVENTION
[0029] According to the present invention, there is provided a pharmaceutical composition comprising:
(a) a poorly soluble pharmaceutical agent; (b) a hydrophobic component, (c) a carrier; and (d) a surfactant.
[0034] The poorly soluble pharmaceutical agent may have a melting point of up to 110° C. The melting point of the pharmaceutical agent or active may be up to 105° C., or up to 100° C. According to the Biopharmaceutical Classification System (BCS), if the ratio of the highest unit dose of a drug to its minimum aqueous solubility (in the pH range 1.0-7.0 at 37° C.) is >250 ml, the drug is considered poorly soluble.
[0035] A co-melt of the poorly soluble pharmaceutical agent with a hydrophobic component, a carrier and a surfactant is introduced as droplets into a cold hardening liquid. This rapid or quench cooling of the molten drug converts it into an amorphous state. Amorphous materials have higher free energy than their crystalline counterparts and as a result exhibit higher apparent solubility and faster dissolution rates. This in turn can lead to higher bioavailability of poorly-soluble drugs whose absorption is dissolution-rate limited. The final composition of the invention is a solid preconcentrate that upon oral intake, forms an emulsion (e.g. a microemulsion) when exposed to gastro-intestinal fluids. The invention functions by causing the amorphous drug to stay dissolved in the lipid or hydrophobic phase of the emulsion and/or in the micellar phase of the surfactant, thereby enhancing drug absorption and bioavailability.
[0036] Suitable pharmaceutical agents include fenofibrate (m.p 79-82° C.), benzocaine (m.p. 88-90° C., chlorambucil (m.p. 64-66° C.), cyclophosphamide (m.p. 41-45° C.), flurazepam (m.p. 77-82° C.), ketoprofen (m.p. 94° C.), lidocaine (m.p. 68-69° C.), nicorandil (m.p. 92-93° C.), oxprenolol (m.p.79-80° C.), piribedil (m.p. 98° C.), pirprofen (m.p.98-100° C.), suloctidil (m.p. 62-63° C.), tropinone (m.p. 41-42° C.), trimipramine (m.p. 45° C.), trimethadione (m.p. 46° C.), diethylcarbamazine (m.p. 48° C.), cyclandelate (m.p. 56° C.), quinine (m.p. 57° C.), scopolamine (m.p. 59° C.), promethazine (m.p 60° C.), triprolidine (m.p. 60° C.), gemfibrozil (m.p.62° C.), dinoprostone (m.p. 67° C.), etomidate (m.p.67° C.), trimeprazine (m.p 68° C.), isosorbide dinitrate (m.p. 70° C.), bleomycin (m.p 71° C.), thioridazine (m.p 73° C.), mitotane (m.p. 77° C.), chlorphenesin (m.p. 78° C.), allylestrenol (m.p. 80° C.), ethambutol (m.p. 88° C.), carisoprodol (m.p. 92° C.), benzocaine (m.p. 92° C.), maprotilin (m.p. 93° C.), ethotoin (m.p. 94° C.), nabumetone (m.p. 80-82° C.) and ibuprofen (m.p. 75-77° C.).
[0037] Particularly preferred active pharmaceutical agents may be selected from fenofibrate, ibuprofen, nabumetone and gemfibrozil.
[0038] Suitably the carrier is gelatin. The gelatin may have a bloom strength of from about 80 to about 350. Preferably the bloom strength is from about 180 to 300. The Bloom test is a test to measure the strength of a gel or gelatin and determines the weight (in grams) needed by a probe to deflect the surface of the gel 4 mm without breaking it with the result expressed in Bloom (grades).The gelatin may be porcine or bovine gelatin.
[0039] The hydrophobic component may be selected from the group consisting of vegetable oils (e.g. corn oil, sesame oil, olive oil, peanut oil, cottonseed oil, sunflowerseed oil), animal oils (eg. omega-3 fatty acids), esterification products of vegetable fatty acids or propylene glycol including fatty acid triglycerides (eg. Miglyol 810, Crodamol GTCC, Neobee M5, Labrafac CC, Labrafac PG, Captex 355, fractionated coconut oil), fatty acid mono- and di-glycerides (eg. Peceol, Maisine 35-1, Imwitor 988, Capmul MCM). They may also be selected from long-chain fatty alcohols (eg. stearyl alcohol, cetyl alcohol, cetostearyl alcohol), sorbitan esters (Span 80, Arlacel 20), or phospholipids (eg. egg lecithin, soybean lecithin). Preferredglycerides include Maisine 35-1, Peceol, Capmul GMO, Cithrol GMO.
[0040] The surfactant may have a HLB value of 14-16. As is well known to those of skill in the art, the hydrophilic-lipophilic balance of a surfactant is a measure of the degree to which it is hydrophilic or hydrophobic which is determined by calculating values for the different regions of the molecule. An HLB value of 0 corresponds to a completely lipophilic/hydrophobic molecule, and a value of 20 corresponds to a completely hydrophilic/lipophobic molecule.
[0041] Suitable surfactants include polyoxyl 40 hydrogenated castor oil, Gelucire 44/14 and 50/13, Labrasol, Acconon MC-8, Acconon C-44, PEG-35 castor oil.
[0042] The active pharmaceutical agent may be present in an amount of from about 1 to about 15%w/w based on the total weight of the composition. Preferably it is present in an amount of between 5% and 12%, preferably 7 and 10% w/w.
[0043] The weight ratio of active pharmaceutical agent to surfactant may be in the range 1:1.6 to 1:1.29, preferably 1:1.5 to 1:1.4.
[0044] The formulation may be an immediate release formulation.
[0045] The composition may also be formulated as seamless spheres comprising:
[0046] (a) a poorly soluble pharmaceutical agent;
[0047] (b) a hydrophobic component,
[0048] (c) a carrier; and
[0049] (d) a surfactant.
[0050] The spheres or cores may typically have a diameter in the range of 0.5 mm to 7.0 mm, preferably 1.0 mm to 2.5 mm, more preferably, 1.4 mm to 1.7 mm.
[0051] In another aspect, the invention provides a method of manufacturing the pharmaceutical composition of the present invention comprising the steps of:
[0052] (i) melting together the pharmaceutically active agent, the hydrophobic component and the surfactant at a temperature greater than the melting point of the agent to produce a solution;
[0053] (ii) dispersing gelatin in water in a ratio of 0.8:1 to 1.2:1 by weight and allowing it to swell;
[0054] (iii) adding the solution produced in step (i) to the remaining quantity of water which is maintained at a temperature just below its boiling point to form an emulsion;
[0055] (iv) adding the swollen gelatin to the emulsion of step (iii) and allowing the gelatin to dissolve.
[0056] The process of the invention thus involves the use of a molten active ingredient to produce a solid emulsion pre-concentrate which is the final dosage form. The particles of the active ingredient are standard-sized. In other words, it is not necessary to use a micron-sized or nanonised active ingredient particle in the process.
[0057] The resultant mixture may be processed to produce seamless, spherical beads of size 1.4-1.7 mm in diameter. The mixture may be processed using a Spherex™ technology seamless spherical microcapsule manufacturing device, to produce seamless spherical microcapsules.
[0058] One aspect of the present invention involves the manufacture of spheres comprising a poorly soluble active using the process described in EP2586429.
[0059] Also provided for is a composition according to the present invention for use as a medicament.
[0060] Advantageously, the method of manufacture is a single pot process wherein fenofibrate, polyglycolized glyceride and gelatine are mixed together and processed into spheres. The method of manufacture is significantly simpler than that of alternative fenofibrate products. For example the method of manufacture of Antara®, Tricor® and Fenoglide® involve multiple steps and complex processing methods, primarily a pre-treatment of fenofibrate (e.g. size reduction) before a final dosage form is produced.
[0061] Also provided is a composition according to the present invention for use in the treatment of hyperlipidaemia or mixed dyslipidaemia, hypercholesterolaemia and hypertriglyceridaemia.
[0062] The present invention provides an improved immediate release fenofibrate formulation, which has enhanced dissolution and absorption profiles. Advantages include reduced dose dumping, less variability in absorption compared to existing formulations, and much faster release and dissolution due to processing at the melt temperature of the drug, the minicapsule formulation and increased surface area of the spheres. Furthermore, the present invention does not require the addition of disintegrants to achieve this enhanced dissolution profile.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] Embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings in which:
[0064] FIG. 1 shows the dissolution profiles for fenofibrate formulations in accordance with the invention;
[0065] FIG. 2 shows the dissolution profiles for ibuprofen formulations in accordance with the invention;
[0066] FIG. 3 shows the dissolution profiles for gemfibrozil formulations in accordance with the invention;
[0067] FIG. 4 shows the dissolution profiles for nimodipine formulations in accordance with the invention;
[0068] FIG. 5 shows the dissolution profiles for nifedipine formulations in accordance with the invention;
[0069] FIG. 6 shows the dissolution profiles for nabumetone formulations in accordance with the invention,
[0070] FIG. 7 shows Individual subject plots from bio-study comparing the 48 mg product (T1) of the invention against the Tricor 48 mg nano product (R), and
[0071] FIG. 8 shows the Mean plot from Bio-Study leg comparing the 48 mg product of the invention with standard sized API versus Tricor 48 mg nanonised product.
DETAILED DESCRIPTION OF THE INVENTION
[0072] The gelatin spheres of the present invention, incorporating fenofibrate, were manufactured according to the teachings of Freund Industrial Co. Ltd. EP2586429 the teachings of which are incorporated herein by reference. This technology is based on the principle that a laminar liquid jet can be broken into equally sized droplets by a superimposed vibration. When the droplets come in contact with a hardening liquid, they undergo gelation leading to the formation of spheres. This technique enables high-speed production of uniformly sized spheres.
[0073] Gelatin is obtained by the partial hydrolysis of collagenous material, such as skin, connective tissues, or animal bones. There are two main classes of gelatin, Type A gelatin, which is obtained from acid-processing of porcine skins and exhibits an isoelectric point between pH 7 and pH 9; and Type B gelatin which is obtained from the alkaline-processing of bovine bone and skin and exhibits an isoelectric point between pH 4.7 and pH 5.2. It will be appreciated by those skilled in the art that varying blends of gelatin are available with varying bloom strength characteristics.
[0074] In the examples disclosed below, porcine and bovine derived gelatin are used, however, the skilled person will be appreciate that other sources of gelatin are equally suitable.
EXAMPLE 1
[0075] Objective: To enhance aqueous solubility by combining a low melting point, poorly soluble drug with a system consisting of a hydrophobic component (e.g. a monoglyceride such as Maisine 35-1), a surfactant with a high HLB value (14-16) (e.g. Polyoxyl 40 hydrogenated castor oil, Tradename: Kolliphor RH40) and a carrier, preferably gelatin (either procine or bovine derived with bloom strength in the range 180-300). 2 poorly soluble drugs, Fenofibrate and Ibuprofen, having a low melting point were chosen to test the utility of the above composition. Details of the trials are provided in the table below. Two ratios of Maisine/Kolliphor, 1:1.8 and 1:2.7 were tried as shown in the last row of the table.
[0000]
% w/w
EXPROD-
0286A,
0295A,
EXPROD-
EXPROD-
EXPROD-
EXPROD-
Batch No.
0303B
307A
0295B
0314A
0314B
Fenofibrate
8.99
8.99
8.99
0
0
Ibuprofen
0
0
0
8.99
8.99
Maisine
8.99
8.99
8.99
8.99
8.99
35-1 (M)
Kolliphor
16.374
16.34
24.51
16.34
24.51
RH40 (K)
Gelatin
65.68
65.68
57.51
65.68
57.51
Drug:M:K
1:1:1.8
1:1:1.8
1:1:2.7
1:1:1.8
1:1:2.7
ratio
[0076] Manufacturing Procedure: Fenofibrate (or Ibuprofen). Maisine 35-1 and Kolliphor RH 40 were melted together at a temperature greater than the melting point of the drug (Fenofibrate: 79-81° C., Ibuprofen: 75-77° C.) to obtain a clear solution. Gelatin was dispersed in water in a 1:1 ratio by weight and allowed to swell. The drug/solubiliser solution was added to the remaining quantity of water (heated at 95° C.) under stirring to form an emulsion. Of the total amount of water that is weighed out for the formulation, one part is used to swell the gelatin and the remaining part is mixed with the drug and solubliser and heated up. The swollen gelatin was added to this emulsion and stirred until the gelatin dissolved. The final solid content of the system was between 27-30% w/w. The resulting mixture was used to form spherical beads of size 1.4-1.7 mm using the SPHEREX™. During processing, the temperature of the drug/solubiliser/gelatin liquid was maintained above the melting point of the drug except in case of EXPROD-0307A where a lower liquid temperature (68-73° C.) was used.
[0077] Dissolution profile: The drug release profiles of the above formulations and the reference products (TRICOR ® 48 mg Fenofibrated tablets and Buplex® 200 mg Ibuprofen tablets) was tested in biorelevant dissolution media; using Fasted State Simulated Intestinal Fluid (FaSSIF) for Tricor® and Fasted State Simulated Gastric Fluid (FaSSGF) for Buplex®. USP Apparatus I (Paddle) was used.
[0078] Volume of media: 900 ml;
[0079] Media temperature: 37° C.;
[0080] Paddle rotation speed: 75 rpm;
[0081] Samples taken:
[0082] 5, 10, 15, 20, 30 and 45 minutes (for EXPROD-0286A, 0314A and 0314B)
[0083] 15, 30, 60, 120, 180 and 240 minutes (for all other batches)
[0084] Observations: A significant increase in % drug dissolved was observed with all formulations with respect to the prior art marketed products. In case of Fenofibrate, a 1:1.8 ratio of Maisine: Kolliphor proved optimal whereas with Ibuprofen, a 1:2.7 ratio of Maisine:Kolliphor showed higher dissolution than a 1:1.8 ratio.
EXAMPLE 2
[0085] A number of formulations manufactured as described in the previous example were made up using different APIs as set out below:-
[0000]
Batch No.
% w/w
API
8.99
Maisine 35-1
8.99
Kolliphor RH 40
16.34-24.51
Gelatin (225 bloom)
57.51-65.66
[0086] The APIs used were:-
[0087] Fenofibrate, melting point=79-82° C.
[0088] Ibuprofen, melting point=75-78° C.
[0089] Gemfibrozil, melting point=58-61° C.
[0090] Nimodipine, melting point=123-126° C.
[0091] Nifedipine, melting point=172-174° C.
[0092] Nabumetone, melting point=80-82° C.
[0093] The dissolution rate of the API form in solubility of each of the formulations was then compared with that of commercially available formulations of the same API, and the results are shown in FIGS. 1 to 6 .
[0094] The method used to measure the dissolution rate is as described under ‘dissolution profile’ in the previous example. Fasted State Simulated Intestinal Fluid (FaSSIF) was used for Fenofibrate, Nifedipine, Nimodipine and Nabumetone while Fasted State Simulated Gastric Fluid (FaSSGF) was used for Ibuprofen and Gemfibrozil. All other conditions remained the same.
[0095] As can be seen from the Figures, the rate and extent of dissolution of the actives which have a melting point below about 110° C. and which were formulated in accordance with the invention, were significantly higher when compared to the currently available commercial version of the same active. This is likely due to the generation of a supersaturated system in which the concentration of drug dissolved is in excess of its equilibrium solubility. The generation of the supersaturated system could be attributed to the conversion of the API from a crystalline to an amorphous state as mentioned previously. Through achieving supersaturation, it has thus become possible to design a formulation that would yield significantly high intraluminal concentrations of the drug than the thermodynamic equilibrium solubility, thus enhancing intestinal absorption and bioavailability. The same result was not found for actives with a much higher melting point.
EXAMPLE 3
[0096] Bio-Study data Comparing 48 mg product of the invention with standard sized API versus Tricor 48 mg nanonised product
[0097] A randomized, single dose, crossover study was conducted to compare the pharmacokinetic parameters (Tmax, Cmax, AUCO-t and AUC0-inf), for a 48 mg fenofibrate product manufactured in accordance with the invention using a standard sized (i.e. not micronized or nanonised) API, and for the commercially available Tricor 48 mg nanonised product. 21 healthy subjects participated in the study. Subjects received 2 separate drug administration treatments (Test and Reference) in assigned periods, one treatment per period, according to the randomization schedule. Dosing days were separated by a wash out period of at least 7 days. Blood samples were drawn prior to dosing (pre-dose) and at 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 7.0, 8.0, 10.0, 12.0, 24.0, 48.0, 72.0 and 96.0 hours.
[0000]
API
AUC0-t
Particle
Strength
Tmax
Cmax
(ng · hr/
AUC0-inf
Product
Size
(mg)
(hr)
(ng/mL)
mL)
(ng · hr/mL)
Invention
Standard
48
1.71
3,107
70,478
76,572
Tricor
Nano
48
2.19
3,668
79,909
87,186
[0000]
90% Confidence
Cmax
AUC0-t
AUC0-inf
Interval (Invention V's Tricor)
(ng/mL)
(ng · hr/mL)
(ng · hr/mL)
1n-transformed Lower
73.93
80.25
80.7
1n-transformed Upper
97.18
96.81
94.8
Power (%)
85.3
98.7
99.8
[0098] Based on 1n-transformed fenofibric acid data, the 90% confidence intervals for AUC0-t and AUC0-inf are within the 80-125% range (for bioequivalence). Therefore when comparing the 48 mg product of the invention containing standard API versus the Tricor 48 mg product with nano sized API, the extent of absorption from both products is equivalent. The product of the invention also exhibited a shorter Tmax value than Tricor however the Cmax was not within the 80-125% range. Clearly a shorter Tmax value is desirable for certain drugs such as painkillers.
[0099] Therefore it appears that the inventive 48 mg product delivered the same amount of fenofibric acid as Abbot's Tricor 48 mg product and shorter Tmax under single-dose and fasting conditions.
[0100] While the pk parameters for the inventive dosage form indicate that it may not be bioequivalent to Tricor on Cmax the results from several individual subjects suggest that the inventive dosage form can be bioequivalent to Tricor on Cmax—see FIGS. 7 a to d from individual subject plots and a mean plot of a study leg with 14 subjects dosed with either the inventive product or Tricor (see FIG. 8 ).
EXAMPLE 4
[0101] Bio-Data 48 mg product of the invention with standard sized API versus Antara 43 mg micronized product
[0102] When compared to published data for a micronised API product (Antara 43 mg) the product of the invention appears to have a significantly better AUC0-t, AUC0-inf and Cmax indicating that this product may denote a superior performance in terms of the amount and rate of fenofibric acid absorbed.
[0103] The words “comprises/comprising” and the words “having/including” when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
[0104] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. | The present invention relates to improved pharmaceutical compositions of pharmaceutically active agents, having high bioavailability and to a method for preparing such compositions. | 0 |
CROSS-REFERENCE(S) TO RELATED APPLICATION(S)
[0001] The present invention claims priority of Korean Patent Application No. 10-2009-0128317, filed on Dec. 21, 2009, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a technique for suppressing unwanted electromagnetic waves and noise generated in a multilayer board; and more particularly, to a multilayer board for suppressing unwanted electromagnetic waves and noise, by applying both decoupling capacitors (DeCaps) and an electromagnetic wave suppression structure including an electromagnetic bandgap (EBG) that are partially placed only at specific areas, such as in the vicinity of noise generating devices and/or noise-sensitive parts, on a power plane or ground plane in a multilayer board.
BACKGROUND OF THE INVENTION
[0003] Recently, as wired/wireless broadcasting and telecommunication-related technologies and services have been rapidly developed, and thus the level of users' demand for products has been increasing, advanced information communication equipment and systems are being equipped with various functions and becoming smaller in size so as to be easily carried. To implement this, high-speed digital systems are becoming faster and wider in bandwidth. As the clock frequency falls within the range of several GHz with such increase in the operating speed of the advanced equipment and systems, the problem of signal/power integrity and electromagnetic interference, which is caused by simultaneous switching noise (SSN) generated in a multilayer package or in a multilayer PCB structure, is considered as one of the most important issues in designing the chip/package and PCB of a high-speed system.
[0004] First, the multilayer PCB and package structure will be described. In the multilayer PCB and package structure, generally, a power plane and a ground plane constituting a power distribution network (PDN) are paired and placed inside the multilayer structure, which form a parallel plate waveguide configuration. Shown in FIG. 1 is a mechanism in which noise is generated in a PDN including power and ground planes due to layer arrangement, signal flow, and a high-speed switching device, such as an IC chip, in a multilayer PCB and package structure using a high-speed signal.
[0005] FIG. 1 is a view showing a signal flow and noise generation mechanism in a multilayer PCB and package structure using a high-speed signal.
[0006] Referring to FIG. 1 , simultaneous switching noise (SSN) 102 is known to be the most serious noise in a multilayer PCB and chip/package structure. The SSN 102 , also referred to as Delta-I noise or ground bounce noise (GBN), is generated by time-varying currents that change fast in a high-speed digital circuit. The SSN 102 generated between the power plane and a ground plane affects the signal/power integrity of the circuits and also causes unwanted electromagnetic interference (EMI) 104 to be radiated from the edges of a PCB board. Thus, the SSN 102 is becoming an important issue in high-speed digital systems operating at a low voltage level at a high-speed clock frequency.
[0007] A recent high-speed digital system has several hundreds of input/output gates for simultaneous switching. If a fast current flows through vias in the multilayer PCB/package due to simultaneous switching of the large number of gates, unwanted noise (SSN 102 ) is generated between the power plane and ground plane as shown in FIG. 1 , and the generated SSN 102 is propagated across the PCB/package by a resonance mode of a parallel conducting plate and then unwanted EMI 104 is radiated from the edges of the PCB/package. That is, the SSN 102 is inductive noise generated when many output terminals of the digital circuit simultaneously switch. Since the amount of the SSN 102 depends on the configuration and current path of the PCB/package, it is difficult to measure a precise amount of the noise. However, the noise can be represented most simply by the following equation:
[0000]
V
noise
=
N
·
L
eq
i
t
Equation
(
1
)
[0008] wherein V noise is a noise voltage, N is the number of simultaneously switching gates, and L eq is an inductance value caused by current flowing through each driver during simultaneous switching.
[0009] So far, one of the most typical methods to solve the problem of signal/power integrity or EMI generated by SSN in analog and digital systems is to mount a device having a large capacitance, which is called a decoupling capacitor (DeCap), between the power layer and the ground layer. Research for eliminating a parasitic inductance component of the power distribution network (PDN) and properly supplying power to an integrated circuit device by the decoupling capacitor has been continuously conducted. However, the mounting of the DeCap on the PCB increases production costs, and also occupies the space of the PCB board, thus making the placement of various devices restrictive. Also, the parasitic inductance component of the DeCap may cause another parallel resonance frequency. Due to the parasitic inductance, the DeCap can operate only up to several hundreds of MHz, and thus the SSN having a GHz frequency component, which has become a problem in recent high-speed digital systems, cannot be eliminated.
[0010] The most frequently used method in efforts to reduce the parasitic inductance component of the DeCap is an embedded thin film capacitor that has a thin film material having a high dielectric constant disposed between power and ground planes. The use of the embedded thin film capacitor makes SSN reduction characteristic improve even in a higher frequency band than that of the DeCap. However, the embedded thin film capacitor also has a limited frequency band of several hundreds of MHz for use, and in order to put the embedded thin film capacitor to practical use, additional research on the composition of a material having a high dielectric constant and processing techniques using the same is required.
[0011] Besides, various methods, such as stitching vias, ground filling, and the like, have been proposed, but most of the methods are disadvantageous in that they operate locally in limited areas rather than across the substrate and show SSN suppression characteristics only in a narrow frequency band less than GHz, and thus it is known their effects are known to be insignificant in the current high-speed systems.
[0012] Meanwhile, new methods for solving the problems caused by SSN in a GHz band are being studied, and research is ongoing to reduce EMI by eliminating SSN in a chip/package and multilayer PCB structure and thus improving power integrity/signal integrity (PI/SI), by using an electromagnetic bandgap (EBG) structure highly applicable as an EMI reduction technique in a GHz band, that is, an EBG structure having a high impedance characteristic in a specific frequency band to provide a wide bandgap characteristic for currents flowing on surfaces. Reducing SSN by using an EBG in the multilayer PCB/package structure allows more effective PI/SI reduction and EMI suppression than using a DeCap or embedded thin film capacitor, and shows more excellent characteristics in selecting a frequency band to be suppressed.
[0013] However, a mushroom-type EBG structure formed in a double-layer structure has disadvantages that it is difficult to manufacture blind vias and the like in terms of process steps and additional costs are required. To overcome this problem, there has been suggested a single-plane EBG structure using periodic structure of an appropriate pattern on a ground plane or power plane. Although this structure can attain considerable noise reduction in a power distribution network (PDN) having a parallel plate waveguide configuration, it is disadvantageous in that it affects high-speed signals flowing over the ground/power planes to which the EBG structure is applied, and there is a limitation on the lowest frequency of a frequency band to be suppressed. Moreover, in case where an EBG structure is provided only on the ground plane or power plane, self-impedance at the region where the EBG structure is placed, especially in a low frequency band, increases, and thus the generation of unwanted electromagnetic waves becomes more dominant.
SUMMARY OF THE INVENTION
[0014] In view of the above, the present invention provides a multilayer board for suppressing unwanted electromagnetic waves and noise, which can apply both decoupling capacitors (DeCaps) and an electromagnetic wave suppression structure including an electromagnetic bandgap (EBG) that are partially placed only in specific areas, such as in the vicinity of noise generating devices and/or noise-sensitive parts, on a power plane or ground plane in a multilayer board.
[0015] Further, the present invention provides a multilayer board for suppressing unwanted electromagnetic waves and noise, which can widen a suppression frequency band from DC up to several tens of GHz (e.g., DC to 99 GHz) and minimize the effects on signals, while maintaining the characteristic of suppressing unwanted electromagnetic waves and noise, by disposing both an electromagnetic wave suppression structure and DeCaps, the electromagnetic wave suppression structure including an EBG used to suppress unwanted wideband electromagnetic waves or noise, such as SSN, generated in a multilayer board structure of electromagnetic devices and systems using a high-speed signal.
[0016] In accordance with the embodiment of the present invention, there is provided a multilayer board for suppressing unwanted electromagnetic waves and noise, including:
[0017] a power plane and a ground plane constituting a power distribution network;
[0018] an electromagnetic wave suppression structure placed on the power plane or the ground plane; and
[0019] a decoupling capacitor placed on the power plane or the ground plane, wherein the electromagnetic wave suppression structure and the decoupling capacitor are placed together.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The objects and features of the present invention will become apparent from the following description of embodiments, given in conjunction with the accompanying drawings, in which:
[0021] FIG. 1 is a view showing a signal flow and noise generation mechanism in a multilayer board structure using a high-speed signal;
[0022] FIGS. 2A and 2B are views showing the placement of electromagnetic bandgap unit cells and a decoupling capacitor applied onto a single plane in accordance with an embodiment of the present invention;
[0023] FIG. 3 shows a cross-sectional structure in a circuit model of a power plane and ground plane in which an electromagnetic bandgap structure and a decoupling capacitor structure are partially placed on a single plane in accordance with the embodiment of the present invention;
[0024] FIG. 4 is a graph showing comparison results of the noise suppression characteristics of the partially placed electromagnetic bandgap and decoupling capacitor structure in accordance with the embodiment of the present invention;
[0025] FIG. 5 is a graph showing the noise suppression characteristics of the partially placed electromagnetic bandgap and decoupling capacitor structure in accordance with the embodiment of the present invention;
[0026] FIGS. 6A to 6C show a structure in which an electromagnetic wave suppression structure is partially applied only to the power plane and a decoupling capacitor is placed only in the vicinity of a noise generating source in accordance with the embodiment of the present invention;
[0027] FIGS. 7A to 7C show an example of a structure in which an electromagnetic bandgap structure of a different size is partially applied to the ground plane and the power plane, and DeCaps are placed at specific positions around a noise generating source in accordance with the embodiment of the present invention.
[0028] FIGS. 8A and 8B are views showing a triangular electromagnetic wave suppression structure and a decoupling capacitor placed only in the vicinity of a noise generating source in accordance with the embodiment of the present invention; and
[0029] FIGS. 9A to 9F are views showing various methods of placing a decoupling capacitor in a multilayer board structure where a partially placed electromagnetic bandgap structure is applied in accordance with the embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0030] Hereinafter, the embodiment of the present invention will be described in detail with reference to the accompanying drawings which form a part hereof.
[0031] FIG. 1 has illustrated a mechanism in which noise is generated, due to signal flow and a high speed switching device such as an IC chip, in a power distribution network (PDN) having a parallel plate waveguide shape and being composed of power and ground planes, in a multilayer printed circuit board (PCB) and package structure using a high-speed signal. As for a signal transmission path in the multilayer PCB and package structure of FIG. 1 , a return current path is established not through the ground plane alone but along a path where the input impedance of each position becomes lower as the frequency of a signal increases. That is, it can be seen that, when a high-speed signal is used, both of the ground plane and the power plane are used as the return current path.
[0032] FIGS. 2A and 2B show structures of the PDN in which DeCaps and an electromagnetic wave suppression structure including EBG unit cells are arranged, in a multilayer board structure, in accordance with the embodiment of the present invention. Throughout the present invention, the multilayer board includes a multilayer PCB and a multilayer package board.
[0033] In FIG. 2A , a DeCap 202 and an electromagnetic wave suppression structure 200 are partially placed only in the vicinity of a noise source or noise-sensitive device on the power plane or ground plane. In FIG. 2B , for comparison of unwanted electromagnetic waves and noise suppression performance, an electromagnetic wave suppression structure 250 is fully placed across the power plane or ground plane of a PDN structure and a DeCap 252 is placed at the same position as the DeCap 202 of FIG. 2A .
[0034] In general, as the number of EBG structures having the same configuration increases, the electromagnetic wave suppression characteristics gets better but the frequency bandwidth to be suppressed is almost constant. Therefore, from an engineering point of view, once the suppression characteristics required for SSN reduction are determined, the number of EBG unit cells between an electromagnetic noise source and parts to be protected can be set.
[0035] Although different depending on EBG structure, at least two EBG unit cell structures are required in order to obtain suppression characteristics of more than about −30 dB. However, even if one EBG unit cell is placed in the vicinity of a noise source or a noise-sensitive device depending on a suppression frequency band or suppression level required for the system, unwanted electromagnetic waves and noise suppression characteristics can be obtained.
[0036] Moreover, the generation and transmission of unwanted electromagnetic waves can be suppressed even in a frequency band less than several hundreds of MHz by using the DeCap as well as by partially placing the electromagnetic wave suppression structure. P 1 to P 4 shown in FIGS. 2A and 2B are ports used in simulation or measurement in order to show the noise suppression characteristics of the electromagnetic wave suppression structure.
[0037] FIG. 3 shows a cross-sectional structure in a circuit model of power plane and ground plane in which an EBG structure 200 and a DeCap structure 202 are partially placed on a single plane as shown in FIG. 2A , in accordance with the embodiment of the present invention.
[0038] The present invention is intended to apply both an electromagnetic wave suppression structure and DeCap to power plane or ground plane structures used inside a multilayer board of three or more layers. Although FIG. 3 describes only the power and ground plane structures for convenience of explanation, the proposed unwanted electromagnetic waves and noise reduction structure is applicable to the power distribution network (PDN) including these power and ground planes. That is, the power plane and the ground plane are embedded in pairs even in a multilayer structure of three or more layers, and thus, the proposed structure is also applicable to the multilayer structure of three or more layers.
[0039] FIG. 4 is a graph showing comparison results of the noise suppression characteristics of the partially placed EBG and DeCap structure in accordance with the embodiment of the present invention, which shows the noise transmission and suppression characteristics of the EBG placement structure proposed in FIGS. 2A and 2B in the vicinity of the substrate (at positions P 2 to P 4 ) when P 1 is assumed to be a noise source.
[0040] To exhibit the excellence of the noise suppression characteristics of the proposed structure, a simulation was conducted on the noise transmission characteristics in PCB boards having different configurations depending on the placement of an electromagnetic wave suppression structure and the presence or absence of a DeCap. Also, a simulation was conducted on a double-sided PCB only composed of a conductor of the same size, and the result (reference board) was indicated in FIG. 4 .
[0041] As shown in FIG. 4 , in case where both of the partially placed electromagnetic wave suppression structure and the DeCap are used, noise is sufficiently suppressed from DC to 5 GHz. That is, sufficient noise suppression characteristics can be obtained only by placing the EBG structure (PEBG w DeCap ( 402 )) in a specific area without fully placing the EBG structure (FEBG w DeCap ( 404 )) across the power/ground planes, and the DeCap can be used to suppress the unwanted noise at the lowest frequency range below the bandgap of EBG, which is the disadvantage of the exiting single-plane EBG structure, to be lowered to DC. Thus, it can be said that the EBG structure with DeCap (PEBG w DeCap ( 402 )) can be sufficiently used as a suppression structure in the entire frequency band where noise may be generated. Moreover, the partially placed EBG structure can minimize the effects on the signals by properly placing a high-speed signal.
[0042] FIG. 5 is a graph showing the noise suppression characteristics of the partially placed EBG and DeCap structure in accordance with the embodiment of the present invention, which shows the noise suppression characteristics of the unwanted electromagnetic waves and noise suppression structure proposed in FIGS. 2A and 2B in the vicinity of the substrate (at positions P 2 to P 4 ) when P 1 is assumed to be a noise source.
[0043] FIGS. 6A to 6C show a structure in which an electromagnetic wave suppression structure is partially applied to the power plane and DeCaps are placed only in the vicinity of a noise generating source in accordance with the embodiment of the present invention.
[0044] Referring to FIG. 6A , an electromagnetic wave suppression structure 600 and DeCaps 602 are placed together around a noise generating device in a power plane and ground plane structure. Referring to FIG. 6B , in case where a noise generating device and a noise-sensitive part co-exist in the power and ground plane structure, an electromagnetic wave suppression structure 610 and DeCaps 612 are partially placed together around the noise generating device and another electromagnetic wave suppression structure 610 is additionally placed in the vicinity of the noise-sensitive part.
[0045] Here, the electromagnetic wave suppression structures 610 separately placed in the two areas may have different electromagnetic wave suppression frequency bandwidths in order to widen the noise suppression frequency bandwidth.
[0046] Referring to FIG. 6C , in case where a noise generating device or noise-sensitive part is formed over a wide area, or the noise-sensitive part is spaced apart from the vicinity of the noise generating device, an electromagnetic wave suppression structure 620 that is partially placed together in the vicinity of the noise generating device is formed over a wider area having more EBG unit cells than the electromagnetic wave suppression structure 610 in FIG. 6B is.
[0047] As shown in FIGS. 6A to 6C , the EBG structure is placed in the vicinity of an electromagnetic wave-sensitive device as well as a noise generating source, thereby improving a noise suppression effect on the corresponding areas. Moreover, although the EBG structure having the same configuration is applied in FIGS. 6A to 6C , an EBG structure having a different size or configuration may be used in order to widen the suppression frequency bandwidth.
[0048] As can be seen in FIG. 1 , generally, not only the ground plane but also the power plane is often used as a return current path of high-speed signals. That is to say, since the EBG structure is partially applied, the power or ground plane to which the EBG structure is not applied can be used as the return current path of a main high-speed signal line.
[0049] Based on this phenomenon, FIGS. 7A to 7C show an example of a structure in which an EBG structure of a different size is partially applied to the ground plane and the power plane, and DeCaps are placed at specific positions around a noise generating source in accordance with the embodiment of the present invention.
[0050] Referring to FIG. 7A , an electromagnetic wave suppression structure 702 and DeCaps 704 are partially placed together only around P 1 where a noise generating source is assumed to be at P 1 position. Referring to FIG. 7B , an electromagnetic wave suppression structure 712 is partially placed only around P 2 where noise generating sources or noise sensitive devices are assumed to be at P 2 position.
[0051] By this placement, as shown in FIG. 7C , the electromagnetic wave suppression structure 702 and the DeCap 704 are partially placed together on the ground plane 700 , and the electromagnetic wave suppression structure 712 is partially placed on the power plane 710 .
[0052] Meanwhile, the EBG unit cell structures, i.e., electromagnetic suppression structures 702 and 712 , placed on the ground plane 700 and the power plane 710 may have different electromagnetic wave suppression frequency bandwidths in order to widen the noise suppression frequency bandwidth, and the electromagnetic wave suppression structures 702 and 712 may be fully placed across the ground plane 700 and the power plane 710 without being limited to the corresponding port where the noise generating sources and/or the noise sensitive devices are present.
[0053] FIGS. 8A and 8B are views showing DeCaps placed only in the vicinity of a noise generating source and a triangular electromagnetic wave suppression structure in accordance with the embodiment of the present invention.
[0054] Referring to FIG. 8A , DeCaps 802 are placed at specific positions around a noise generating source and a triangular electromagnetic wave suppression structure 800 is fully applied across the power plane or the ground plane. Referring to FIG. 8B , DeCaps 812 are disposed at specific positions around a noise generating source and a triangle electromagnetic wave suppression structure 810 is partially applied to the power plane or the ground plane.
[0055] In this manner, the electromagnetic wave suppression structure can be implemented in the shape of various polygons, such as a rectangle, a square, a triangle, a lozenge depending on an implementation method of the EBG unit cells.
[0056] FIGS. 9A to 9F are views showing various methods of placing DeCaps in a multilayer board structure where an EBG structure is partially placed in accordance with the embodiment of the present invention.
[0057] It is seen throughout FIGS. 9A to 9F that an electromagnetic wave suppression structure and DeCaps are partially placed together only around P 1 where the noise generating sources and/or the noise sensitive devices are present.
[0058] Referring to FIG. 9A , on a ground plane 900 , an electromagnetic wave suppression structure 902 and a DeCap 904 are partially placed around P 1 , and the DeCap 904 may be placed at a certain point of the circumference having a radius equal to a preset distance from the port P 1 .
[0059] In FIG. 9B , on a ground plane 910 , an electromagnetic wave suppression structure 912 and eight DeCaps 914 are partially placed around P 1 . FIG. 9C shows that on a ground plane 920 , an electromagnetic wave suppression structure 922 and two DeCaps 924 are partially placed around P 1 , and herein, the two DeCaps 924 are placed above and below the port P 1 . In FIG. 9D , on a ground plane 930 , an electromagnetic wave suppression structure 932 and two DeCaps 934 are partially placed around P 1 , and herein, the two DeCaps 934 are placed on the left and right of the port P 1 .
[0060] Referring to FIG. 9E , on a ground plane 940 , an electromagnetic wave suppression structure 942 and four DeCaps 944 are partially placed around P 1 , and herein, the four DeCaps 944 are placed in a square shape with the port P 1 as the center. Finally referring to FIG. 9F , on a ground plane 950 , an electromagnetic wave suppression structure 952 and four DeCaps 954 are partially placed around P 1 , and herein, the four DeCaps 954 are placed above and below and on the left and right of the port P 1 .
[0061] Meanwhile, the DeCaps shown in FIGS. 9A to 9F , by adjusting capacitance magnitudes and positions, can control the unwanted electromagnetic waves and noise suppression frequency band and noise suppression level.
[0062] Therefore, the noise suppression characteristics can be optimized by selecting an optimum position in consideration of a frequency band to be suppressed, a noise suppression level, placement of parts on the substrate, and the like. Also, in order to adjust the unwanted electromagnetic waves and noise suppression frequency band and noise suppression level, an embedded DeCap having high dielectric constant and placed between the power plane and the ground plane can be used to increase the capacitance of the DeCap and reduce the parasitic inductance thereof.
[0063] As described above, the multilayer board for suppressing unwanted electromagnetic waves and noise in accordance with the embodiment of the present invention has some effects as follows.
[0064] First, unwanted wideband electromagnetic waves and noise generated in the multilayer board structure can be suppressed by DeCaps in a low frequency band and by a partially placed electromagnetic wave suppression structure in a frequency band more than several hundreds of MHz. As the electromagnetic wave suppression structure is partially placed in a specific area, a ground plane or power plane having no electromagnetic wave suppression structure applied thereto can be used as a return current path for high-speed signal lines while maintaining the noise suppression characteristics of the electromagnetic wave suppression structure, thereby improving signal characteristics of an entire system.
[0065] Moreover, noise generation can be reduced by reducing self-impedance by applying both DeCaps and an EBG structure to a noise generating source.
[0066] Further, it is possible to expand the suppression frequency bandwidth or properly adjust the noise suppression level by varying the shape or size of a partially placed electromagnetic wave suppression structure and the position and size of DeCaps. Therefore, an optimum noise suppression environment for performance improvement can be provided depending on the characteristics of a product to be applied.
[0067] While the invention has been shown and described with respect to the embodiments, it will be understood by those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims. | A multilayer board for suppressing unwanted electromagnetic waves and noise includes: a power plane and a ground plane constituting a power distribution network; an electromagnetic wave suppression structure placed on the power plane or the ground plane; and a decoupling capacitor placed on the power plane or the ground plane, wherein the electromagnetic wave suppression structure and the decoupling capacitor are placed together. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to the method of removal of light impurities from caprolactam by distillation with water. The crude caprolactam (epsilon-caprolactam) is obtained from the Beckmann rearrangement of cyclohexanone oxime and must be purified for suitable use as a monomer to prepare polycaprolactam (nylon 6). See pages 425-436, Kirk-Othmer: Encyclopedia of Chemical Technology, Vol. 18, 3d Ed. 1982 (John Wiley) hereby incorporated by reference.
The following are definitions of the terms used in this patent application. By portion is meant 2-98%, preferably 5-90% of a process stream. By low boiling is meant those impurities boiling between the atmospheric boiling point of caprolactam and water. By low water content is meant a content below 10% by weight of water. By crude caprolactam is meant caprolactam with impurities from the process and includes mother liquor from the crystallizer of the caprolactam process. The process used for the invention may be batch or continuous. The crystallization used in the process herein can be single or multistage. Also the distillation used in the process herein can be single or multistage.
Many methods to purify crude caprolactam and other lactams are known. See column 1 of U.S. Pat. No. 3,347,852 hereby incorporated by reference. For a water crystallization process, fractional crystallization or solvent extraction may be used in the crude caprolactam or mother liquor as in U.S. Pat. No. 2,817,661 or U.S. Pat. No. 3,761,467, both hereby incorporated by reference. Multistage centrifuges and freezer crystallizers may be used as in U.S. Pat. No. 2,813,858, hereby incorporated by reference. Crystallization may be used from special solvents as in U.S. Pat. No. 3,966,712, hereby incorporated by reference. Also, solvent may be removed from crystallized lactam by distilling in the presence of water as in U.S. Pat. No. 4,148,793, hereby incorporated by reference.
SUMMARY OF THE INVENTION
This invention is a method to purify crude caprolactam. The improvement consists essentially of taking a portion of the process stream of crude caprolactam having low boiling impurities and distilling the stream in the presence of water by fractional distillation into an overhead containing water and low boiling impurities and bottoms of caprolactam having improved purity and low water content.
This invention, in a second embodiment, is also a method to purify crude caprolactam wherein the improvement comprises taking a low water content stream of crude caprolactam having low boiling impurities, adding water to the stream, distilling the stream by fractional distillation into an overhead containing water and low boiling impurities and bottoms of caprolactam with improved impurities and low water content. The bottoms of the fractional distillation step is recovered and fed to a crystallizer to form crystals of caprolactam. Also, in a preferred second embodiment, only a portion of the stream would be taken from the process to be fed to the first step. Preferably, this stream fed to the first step of the process contains about 0.1% to about 10% by weight of water. Even more preferably, the stream fed to the process of the first step contains about 0.5% to about 3% by weight of water, water is added in the second stage from a ratio from about 0.15 to 1 to about 0.5 to 1 by the weight of the stream of the first step, the distillation of the stream removes from about 4% to about 45% of all impurities as measured by permanganate number, the reflux ratio during said distillation step is between about 0.25 to 1 to about 5 to 1, the caprolactam content of the overheads from the distillation step is below about 3% by weight, and the water content of the bottoms from distillation step is between about 0.1% to 5% by weight.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a schematic showing preferred embodiments of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawing shows the preferred embodiment having ten vessels; the distillation column 7, crystallizer 9, filter 11, thin-film evaporator 14, flasher 17, flasher 18, tank 19, tank 23, tank 36, and distillation column 27. Crude lactam (caprolactam) from the Beckmann rearrangement process, containing water and impurities is fed through line 6 to distillation column 7 where water is distilled overhead through line 8 and lactam and water are fed through line 3 to feed tank 36 through line 37 to crystallizer 9 where water is again taken overhead through line 10 and wet caprolactam crystals are fed through line 12 to filter 11 and the pure caprolactam crystals are removed through line 13 and mother liquor is removed through line 5 to tank 19 where other various impure caprolactam streams are added through line 21. Tank 19 feeds flasher 18 through line 20. Water and caprolactam are removed overhead from flasher 18 in line 22 and caprolactam-rich bottoms are fed through line 1 to caprolactam flasher 17 where caprolactam is flashed overhead through line 2 and bottoms are fed through line 16 to thin-film evaporator 14 which flashes overheads to line 4 and heavy residues are removed through line 15 to recovery or disposal. Overhead lines 2 and 4 are also fed to feed tank 36 and line 37 to crystallizer 9 where water is removed and caprolactam crystals are sent to filter 11 as described above. The process described above is known in the prior art. The improvement is described as follows. All or portions of the streams or flows in lines 1, 2, 3, 4 and/or 5 can be diverted through lines 33, 35, 34, 31, and/or 32 to line 30 which feeds into feed tank 23. The schematic shows the preferred stream 2 being fed through line 32 and feed lines 31, 33, 34 and 35 as alternates or additional streams. Feed tank 23 feeds distillation column 27 through line 24. If feed tank 23 is low in water content, water from source 26 is fed through line 25 into line 24. Water and low boiling impurities are removed overhead from column 27 through line 28, and bottoms containing purified lactam of low water content is sent through line 29 to feed tank 36 through line 37 to crystallizer 9 to be processed as above-described. Reflux to column 27 is through line 38.
EXAMPLES
When crude caprolactam is purified by crystallization from aqueous solution, purified crystals are separated from an aqueous mother liquor containing impurities and considerable amounts of lactam. It is not economical to discard the mother liquor without first recovering most of the lactam in it. Lactam is usually recovered by flash distillation, and it is recycled to crystallization. We have found in a preferred embodiment of this invention that if water is added to the flashed lactam (in the drawing stream Number 2) and this material is subjected to a new, fractional distillation step, after water addition, a large proportion of the impurities can be eliminated as a light aqueous fraction with negligible loss of lactam, leaving a bottoms product for recycle substantially purer than the feed.
Streams from a commercial operation representing stages in the lactam flashing and recycle process and the feed stream to crystallization itself behaved similarly in laboratory distillations, i.e., substantial amounts of impurities could be removd by fractional steam distillation as light fractions. Impurities were measured as permanganate number (PN) (method described in U.S. Pat. No. 3,406,167 and U.S. Pat. No. 3,021,326, both hereby incorporated by reference). Quantitative data are shown in the table as percent PN removed. Water added is shown as percent of feed. Best representative examples include 23-7, 23-12, 23-26 and 23-28. Benefits from removal of these light boiling impurities from the recycled stream are a crystallized product lactam of better quality and increased crystallization capacity for the same product lactam quality. (Overall PN value). Impurities not removed in this way would leave the system as contaminants in the product.
Plant streams tested in this work have the following approximate composition:
TABLE I______________________________________Stream % Lactam % Water Permanganate No.______________________________________1. Bottoms 99 1 20002. Overheads 98 2 20003. Bottoms 92 8 5004. Overheads 99+ <1 15005. Mother Liquor 93 7 2000______________________________________
The above numbers, 1 to 5, indicate the same numbered streams as those in the drawing.
TYPICAL EXPERIMENT
A one-inch (inside diameter) Oldershaw column containing fifteen perforated plates (number of plates can be varied), equipped with a reflux condenser, overhead sample take-off, and a reboiler in bottom of column was used for all experiments.
The Oldershaw column consists of a series of perforated glass plates sealed in a glass tube. Each plate is equipped with a baffle to direct the flow of liquid, a weir to maintain a liquid level on the plates, and a drain pipe. The first plate in a series serves as a small reservoir which is necessary in order to maintain a liquid seal for the drain pipe from the first regular plate. Further description is found in C. F. Oldershaw, Perforated Plate Column, Industrial & Engineering Chemistry, Vol. 13, No. 4, pages 265-268 (April, 1941), hereby incorporated by reference.
Stream 2, the overhead from lactam flasher, is the preferred stream for use in the removal of light impurities as measured by permanganate number.
The feed material containing the water was fed into the side of the column above the fifth plate; although other feed ports were evaluated, the addition at the fifth plate gave best results. Table II shows the parameters and results of many experimental runs on the Oldershaw column. All experiments were carried out under 10 mm Hg pressure. The ratio of light impurities (PN's) to total impurities is highest in stream No. 2. In run of Experiment No. 14-45, no external reflux was used, only internal reflux was occurring. For runs using stream No. 5 as feed, no water was added. For Experiment No. 29-4, an uneven run occurred due to feed pump pluggage.
TABLE II__________________________________________________________________________CONTINUOUS DISTILLATIONS H.sub.2 O Total Over- Added H.sub.2 O head as % as % as % %Expt. of of of % PN Lactam Reflux Feed Rate, Stream NumberNo. Feed Feed Feed Removed Lost Ratio cc/Minute Used as Feed__________________________________________________________________________23-7 33 34.3 33 45 2.7 3:1 1.5 223-11 33 34.3 33 29 0.08 3:1 1.5 223-12 33 34.3 33 27 0.03 3:1 1.5 223-1 33 34.3 31 24 Neg. 1:1 1.5 223-14 33 34.3 21 19 Neg. 2:1 1.5 214-50 33 34.3 30 17 0.005 1:1 2.0 223-3 33 34.3 25 19 Neg. 2:1 1.5 223-13 33 34.3 25 14 Neg. 3:1 1.5 214-49 33 34.3 24 13 Neg. 1:1 2.0 214-45 33 34.3 19 5 Neg. * 3.0 223-24 25 26.5 25 23 Neg. 3:1 1.5 223-26 15 16.7 16 28 0.008 3:1 1.5 223-28 15 16.7 15 27 Neg. 3:1 3.5 223-29 15 16.7 17 25 Neg. 2:1 2.5 223-31 15 16.7 16 24 0.02 1:1 3.5 229-2 25 25.75 25 18 Neg. 3:1 2.0 129-6 25 25.75 27 18 0.8 2:1 2.0 129-4 25 25.75 25 13 0.4 2:1 2.0 123-50 15 15.8 14 12 Neg. 3:1 3.5 123-46 15 15.8 17 10 0.02 1:1 2.5 123-47 15 15.8 15 5 0.06 2:1 3.0 129-7 24 30 26 19 0.7 2:1 2.0 329-9 25 25 26 20 0.2 2:1 2.0 429-11 25 25 20 9 0.01 3:1 1.5 423-45 -- 7 7 20 Neg. 1:1 5.0 523-32 -- 7 10 16 Neg. 1:1 5.0 523-41 -- 7 7 9 Neg. 2:1 5.0 523-40 -- 7 5 4 Neg. 1:1 5.0 523-43 -- 7 6 4 Neg. 3:1 5.0 5__________________________________________________________________________ *Indicates internal reflux only. | This invention is a method of purifying crude caprolactam. The improved method comprises taking a portion of a process stream of crude caprolactam having low boiling impurities and distilling the stream in the presence of water by fractional distillation into an overhead containing water and low boiling impurities and bottoms of caprolactam having improved purity and low water content.
The improvement also comprises taking a low water content stream of crude caprolactam having low boiling impurities and adding water to the stream and distilling the stream by fractional distillation as described above. | 2 |
FIELD OF THE INVENTION
The present invention is directed to a system for storing hydrogen in a confined area and to power systems such as back-up power systems incorporating such hydrogen storage systems.
BACKGROUND OF THE INVENTION
The storage of hydrogen requires great care due to the explosive properties of the gas. As hydrogen becomes a preferred choice as an alternative fuel to fossil fuels there is a need for systems for storing hydrogen in a safe manner at a confined location such as within a building. This is particularly desirable for use in conjunction with a hydrogen fueled power system, for instance a back-up power system, for a facility. Commercially feasible systems for storing and using hydrogen in this manner are not currently available.
SUMMARY OF THE INVENTION
In one aspect the invention provides a hydrogen storage system comprising:
a) at least one high pressure hydrogen gas storage container for storing high pressure hydrogen gas, said at least one high pressure hydrogen gas storage container being disposed in a confined area; b) a vent line extending from said at least one high pressure hydrogen gas storage container to a location outside the confined area wherein said hydrogen gas may be relatively safely released in response to a pre-determined unsafe condition; c) at least one sensor disposed in said confined area for detecting one or more predetermined unsafe conditions relating to the storage of hydrogen gas in the confined area; and d) at least one actuator in communication with said sensor for releasing hydrogen gas from said at least one high pressure hydrogen gas storage container through said vent line to said location outside of said confined area at a minimum pre-determined release rate in response to a signal received from said sensor.
In another aspect the invention provides a power system for providing back-up power to a facility comprising:
a) a generating system disposed at the facility having at least one hydrogen generator and at least one hydrogen powered electrical generator. b) a storage system disposed at the facility having at least one high pressure hydrogen gas storage container for storing high pressure hydrogen gas received from said hydrogen generator, said storage system being disposed within said facility; c) a conduit for supplying hydrogen gas from said at least one hydrogen generator to said storage system; d) a conduit for supplying hydrogen gas from said storage system to said at least one electrical generator; e) a power interruption sensor for sensing an interruption in the supply of electric power from a primary electric power source; f) a back up power actuator in communication with the power interruption sensor for actuating said at least one hydrogen powered electrical generator to generate electricity in response to a signal from said power interruption sensor indicating an interruption in the supply of electricity from said primary electric power source; g) a vent line extending from said at least one high pressure hydrogen gas storage container to a location outside the facility where said hydrogen gas may be relatively safely released in response to a pre-determined unsafe condition; h) at least one unsafe condition sensor disposed in said facility for detecting one or more predetermined unsafe conditions relating to the storage of hydrogen gas in the facility; and i) at least one actuator in communication with said unsafe condition sensor for releasing hydrogen gas from said at least one high pressure hydrogen gas storage container through said vent line to said location outside of said facility at a minimum pre-determined release rate in response to a signal received from said unsafe condition sensor.
In another aspect the invention provides a power system for a facility comprising:
a) hydrogen generator for producing hydrogen; b) a hydrogen powered electrical generator for producing electricity; c) a storage system comprising at least one storage container for storing hydrogen produced by said hydrogen generator, said at least one storage container being connected to deliver hydrogen to said hydrogen powered electrical generator to produce electricity from hydrogen stored in said storage system; d) a fuel station connected to said storage system, said fuel station comprising at least one fuel dispensing device for dispensing hydrogen to one or more hydrogen powered vehicles located at the facility; e) a power interruption sensor for sensing an interruption in the supply of electric power to the facility from a primary electric power source; f) a back up power actuator in communication with the power interruption sensor for actuating said at least one hydrogen powered electrical generator to generate electricity in response to a signal from said power interruption sensor indicating an interruption in the supply of electricity from said primary electric power source.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a power system with a hydrogen storage system in accordance with the present invention.
FIG. 2 is an elevation view of a generator room and a storage room for one embodiment of the system of FIG. 1 .
FIG. 3 is a plan view of the generator room for the system of FIG. 2 .
FIG. 4 is a plan view of the storage room for the system of FIG. 2 .
FIG. 5 is an elevation view of a fueling station for the system of FIG. 2 .
FIG. 6 is a front elevation view of a fuel dispensing device for the fueling station of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
A power system in accordance with the present invention is depicted generally at 10 in FIGS. 1–6 . The system 10 includes a generation system 12 comprising at least one hydrogen generator 14 and at least one hydrogen fueled electrical generator 16 . The system 10 also includes a hydrogen storage system 18 comprising at least one hydrogen storage container 20 . The hydrogen generator 14 receives electrical power from a power source 22 and water from a water source 24 . The hydrogen generator 14 then operates in known manner to produce hydrogen that is then transferred to the storage system 20 . The stored hydrogen may then be used to fuel the electrical generators 16 to produce backup power for a facility or the hydrogen may be used for other purposes such as for fueling a hydrogen receiving device at a fuel station 200 .
The generation system 12 of the preferred embodiment has a hydrogen generator 14 that is a CFA 450 Community Fueler Appliance (TM) manufactured by Stuart Energy Systems Corporation which is able to generate 450 scfh of hydrogen at up to 6,000 psig operating pressure and two hydrogen fueled electrical generators 16 that are Ford Power Products (FPP) hydrogen fueled, packaged internal combustion engine/generator sets (ICE) that will provide up to 135 kW of electrical output each complete with the necessary electrical equipment to produce electricity in a form compatible with the critical building circuits to be powered. Each of the above preferred electrical generator 16 requires 13,000 cfm of air to satisfy the integrated radiator's requirements and an additional 600 cfm for combustion air. Each electrical generator 16 also requires approximately 5250 scfh of hydrogen fuel at 75 psig when running at full load.
The hydrogen storage system 18 of the preferred embodiment has a number of high pressure hydrogen storage containers 20 of sufficient total capacity to supply fuel to the electrical generator 16 to run for a desired period of time (eg. two hours) under desired power conditions. Preferably, the storage containers 20 are conventional cylinders for receiving compressed gas where each storage container 20 has a capacity of 1550 scf at a pressure of 5,000 psig. The storage containers 20 will be designed to restrict the flow from each cylinder to 10 scfs and the total from each bank to 50 scfs, maximum.
The components of the system 10 are mostly disposed in a generator room 30 and a storage room 32 . The generator room 30 houses the hydrogen generator 14 and the electrical generators 16 and the storage room 32 houses the storage containers 20 . The embodiment depicted in FIGS. 2–6 demonstrates one arrangement for the rooms 30 and 32 however it will be appreciated that numerous alternate arrangements are possible while still meeting the objectives of the invention. Thus, in FIGS. 2–6 , the roof 33 of the storage room 32 is constructed with sufficient structural strength to serve as a mezzanine area 35 over the generator room 30 where the electrical generators 16 are located. The hydrogen generator 14 will occupy most of the ground floor of the generator room 30 .
A viewing room 34 is also depicted in the FIGS. 2–5 for viewing the generator room 30 . This is an optional element that is advantageous mainly to provide demonstrations of the operation of the system 10 . The viewing room 34 is equipped with observation windows 36 and access stairs 38 to the generator room 30 . The floor level in the viewing room 34 is above the floor level in the generator room 30 to provide optimum viewing. A master control panel 40 for the system 10 may be located in the viewing room 34 for ease of operation during facility demonstrations or it may be located at any convenient location outside the storage room 32 .
Referring more specifically to the generator room 30 , a ventilation plenum 50 is provided for introducing make-up air ventilation into the room from outdoors. The ventilation plenum 50 preferably delivers approximately 30,000 cfm of unconditioned make-up air and is sized to ensure that the static pressure drop across the radiator fans 52 for the electrical generators 16 is not more than ½ inches of water column, total system. The ventilation plenum 50 preferably extends through the roof 53 and is capped with a Greenheck Model WIH (trademark) pre-fabricated louvered penthouse 54 complete with roof curb 56 and motorized dampers 58 (or equivalent).
A generator room exhaust fan 60 is mounted on the roof 53 and the intake is preferably flush with the underside of the roof deck such that the fan 60 will remove any fugitive hydrogen emissions that may collect in the upper corners of the room. The generator room exhaust fan 60 provides 10,000 cfm of capacity at ½ inch static pressure, total system. The exhaust fan 60 is preferably a Greenheck TAUB (trademark) tube axial flow “upblast” belt drive fan complete with non-sparking impellers and integrated butterfly dampers (or equivalent). The fan 60 is fitted with an appropriately classified electric motor.
The generator room exhaust fan 60 is preferably a start/stop model which is thermostatically controlled to attempt to maintain the room temperature below a desired level (eg. 77° F.). The exhaust fan 60 is also activated by the control system PLC 62 such that the exhaust fan 60 runs for a desired period of time (eg. at least 5 minutes) every hour for general room exhausting. In addition, the fan 60 may be controlled by other devices that are integrated into the system 10 .
A discharge pipe 64 is connected to the hydrogen generator 14 for the venting of excess oxygen and water vapour created by the hydrogen generator 14 during its operation. The discharge pipe 64 extends through the inside of the ventilation plenum 50 and discharges at the roof 53 through the curb box 56 of the pre-fabricated penthouse 54 . The pipe 64 is sized to ensure that the hydrogen generator 14 is not exposed to a pre-determined excessive back pressure (eg. greater than or equal to 4″ water column).
A second discharge pipe 68 is connected to the hydrogen generator 14 for venting excess, low-pressure hydrogen and water vapour. The second discharge pipe 68 preferably extends to the ceiling of the generator room 30 and then is routed through the roof 53 through the curb box 56 of the penthouse 54 . The pipe 68 is sized to ensure that the hydrogen generator 14 is not exposed to a pre-determined excessive back pressure (eg. greater than or equal to 4″ water column).
A supply line 70 extends from the hydrogen generator 14 to the storage containers 20 in the storage room 32 to transfer hydrogen at a desired pressure (eg. 5000 psig). This is described in more detail with reference to the storage room 32 structure.
The electrical generators 16 are placed on a mezzanine in the generator room 30 as depicted in FIGS. 2 and 3 . As discussed above, alternate room arrangements are also contemplated.
Combustion air for the electrical generators 16 is preferably sourced from within the general space 72 of the generator room 30 . The exhausts 74 for the engines 76 of the electrical generators 16 are preferably discharged through the roof 53 via two separate pipes 78 and 80 complete with critical grade mufflers 82 and gravity-activated caps 84 .
The electrical generators 16 are oriented such that their radiators 90 will discharge through two separate suitably sized exhaust plenums 92 disposed in the wall. The exhaust plenums 92 are preferably equipped with outlet dampers 94 and re-circulation air discharge dampers 96 to re-circulate air from the electrical generators 16 back into the generator room 30 under cold weather conditions. The outlets 94 and 96 of the plenums 92 may be fitted with discharge air louvers 98 , complete with drains. The louvers 98 are preferably sized to fill the entire wall area above the mezzanine floor. Any louver area not required for exhaust purposes may be fitted with blanking panels 100 .
Hydrogen fuel for the electrical generators 16 may be provided at a desired pressure (eg. 75 psig) from a pressure regulator station 102 disposed inside the storage room 32 . A single supply line 104 from the storage room 32 extends through the mezzanine floor and branches to a connection point on each engine for the electrical generators 16 .
The generator room 30 is preferably equipped with a thermostatically controlled space heating device 106 that will maintain the temperature in the generator room 30 above a desired level (eg. 68° F.).
The generator room 30 may be equipped with a large access door 108 sized such that the large equipment that will be located in the generator room 30 and any equipment necessary to service that equipment is able to gain access through this door 108 .
Referring now to the storage room 32 , a sufficient number of storage containers 20 are provided to supply enough hydrogen to allow the electrical generator 16 to run for a desired minimum time period (eg. 2 hours) under desired power conditions. In the embodiment depicted in the figures, fifteen containers 20 arranged in three banks 110 are provided. Each container 20 preferably has a capacity of 1550 scf at a pressure of 5,000 psig. The storage containers 20 are designed to restrict the flow from each container 20 to 10 scfs and the total from each bank 110 to 50 scfs, maximum.
The containers 20 are racked horizontally with the bottom 112 of the containers 20 located along a louvered wall and the manifold tubing 114 located facing an opposing wall. The cylinder rack is covered by a sheet metal enclosure 116 that is designed to collect and direct any hydrogen leaks in the containers 20 or manifold piping upward to the opening 118 in the enclosure's roof. The primary hydrogen and temperature sensors 120 are mounted in this opening. This minimizes the detection time of a leak or fire in the storage bank arrangement.
Make-up air intake louvers 130 are located at the lower portion of the outside wall area of the storage room. A louvered, exterior access door 132 , opening outward is also located along this wall. Preferably, none of the louvers 130 and 132 shall have back draft dampers. The louvers 130 and 132 deliver a desired amount (eg. 18,000 cfm) of unconditioned make-up air to the storage room 32 and are sized to ensure that the static pressure drop across the two fans 134 described below is not more than a desired amount (eg. ¼ inches of water column, total system). The louvers 130 and 132 are preferably designed to nominally deliver 250 cubic feet per minute of make-up air per square foot of louver and will require 75 square feet of louvered wall, including the exterior access door 132 .
Storage room exhaust fans 134 are preferably mounted on the roof. The intake for the fans 134 is located in the storage room 32 ceiling at a location that will remove any hydrogen accumulation from the room. The exhaust intake 136 connects to an exhaust air plenum 138 that is preferably constructed of two hour rated dry wall, acoustically lined (or equivalent).
The storage room exhaust fans 134 preferably provide 9,000 cfm of capacity each with a total capacity of 18,000 cfm at ¼ inch static pressure, total system. The fans are preferably two identical Greenheck TAUB (trademark) tube axial flow “upblast” belt drive fans complete with non-sparking impellers and integrated butterfly dampers (or equivalent). The fans 134 are fitted with an appropriately classified electric motor.
The storage room exhaust fans 134 are start/stop models and are activated by the control system PLC 62 such that at least one of the fans 134 runs for a desired period of time (eg. at least 2 minutes every 60 minutes) for general room exhaust. The fan 134 that is activated for this function is preferably alternated such that the running hours of each fan 134 is accumulated approximately equally. In addition, the fans 134 will be controlled by other devices that are integrated into the system 10 .
A pressure relief valve 140 is provided in the fuel line 142 between the outlet 144 of the pressure reducing station and the inlet 146 to the electrical generator fuel line 148 . Each bank of storage containers 20 also requires a high-pressure relief vent line 150 , 152 and 154 . The hydrogen generator 14 also includes a vent line 156 to vent fugitive oxygen and hydrogen emissions and the associated water vapour. This venting will require the installation of four lines constructed of high-pressure steel tubing suitably sized and compatible fittings and valves plus the two lines 64 and 68 described in the generator room 30 section above for the low pressure hydrogen and oxygen and associated water vapour.
The high-pressure relief vent line from the hydrogen generator 14 is an integral part of the hydrogen generator design. Its primary purpose is to maintain adequate back-pressure on the outlet of the hydrogen compressors to ensure proper operation. If an overpressure situation occurs in the storage supply line from the hydrogen generator 14 , the overpressure relief line is discharged into a “blow down” pressure vessel 160 . This vessel 160 is of adequate strength and size to effectively accept the low flow, high-pressure hydrogen from the storage supply line and reduce it to low pressure. The blow down pressure vessel 160 is equipped with a relief valve 162 that allows the low pressure hydrogen and associated water vapour to vent to atmosphere via the hydrogen/water vapour vent line 64 and 68 described in the generator room 30 section above. All other hydrogen relief lines preferably exit the storage room at a desired level (eg. about 7.0 ft) above grade.
The high-pressure hydrogen relief system preferably consists of one pressure relief valve for the hydrogen generator fuel line and three pressure relief valves, one for each of the three banks of storage containers. The hydrogen generator fuel line relief valve is set to relieve at a desired pressure (eg. at 83 psig (110% of design pressure)). The storage relief valves are also set to relieve at a desired pressure (eg. 5,500 psig (110% of design pressure)).
In addition, the high-pressure lines from the three banks of storage are teed and piped to 3 Class 1, Zone 2 rated electrically actuated/pneumatically operated ball valves 166 . These valves provide a closed-loop storage dump capability that is controlled by the system 10 complete with a manual override capability.
The outlets of all four vent lines are connected to a common vent stack 168 . The vent stack 168 is installed at the point where all of the high-pressure vent lines exit the storage room (eg. about 7.0′ above grade). The vent stack 168 is affixed to the exterior wall of the building and extends to a sufficient height (eg. approximately 20.0 ft above grade) where it terminates in an elbow 170 that directs the hydrogen away from the building and is covered with a gravity actuated rain cap 172 .
The Safety Control System (SCS) 174 employs several strategies to ensure that the release of hydrogen into either the generator room 30 or the storage room 32 is avoided. In the unlikely event that a major hydrogen leak occurs, the SCS uses several redundant sensors 174 and associated closed-loop control devices 176 to mitigate the event. The mitigation strategy includes the manual or automatic dumping of a desired amount (eg. at least 95%) of all hydrogen in storage to atmosphere in a desired time period (eg. in less than 5 minutes).
In addition, manually actuated/electrically operated Emergency Stop Devices (ESDs) 180 and Emergency Dump Devices (EDDs) 182 complemented with visual/audible alarm beacons 184 are located in the viewing room, the generator room 30 and outdoors adjacent to the exterior access door to the storage room 32 . The cabinet 188 located adjacent to the exterior storage room door that houses the EDD, 182 also contains a pressure gauge 190 that directly measures the pressure in each of the three banks of storage containers. The gauge allows emergency personnel or qualified operations personnel to ensure that each bank of the storage containers is fully relieved of pressure when the EDD 182 is activated. The EDD 182 can be by-passed by a manual valve 192 located in the same cabinet.
The generator room 30 and the storage room 32 are also equipped with a network of temperature sensors 194 and fusible links 196 to manage the operation of all equipment and safety devices under all fault situations.
Referring to FIG. 6 , a fuel station 200 is shown having at least one hydrogen fuel dispensing device 202 . The fuel dispensing device is connected to the storage containers 20 by a supply line 204 . The dispensing device includes a nozzle 206 and a control device 208 for dispensing hydrogen fuel at a pre-determined pressure to a receiving apparatus such as a vehicle.
The hydrogen-fueled back-up power system thus provides an advantageous alternative to diesel, and other forms of fuel, for back-up electrical power systems. Such a system has industrial, institutional and commercial uses primarily although other uses may become feasible in future. An advantage of the system is that the stored hydrogen can be utilized for other purposes as well provided that the storage maintains a minimum desired amount for providing the back up power system functionality. For instance, the hydrogen may be used for onsite vehicle fueling.
It is to be understood that what has been described is a preferred embodiment to the invention. If the invention nonetheless is susceptible to certain changes and alternative embodiments fully comprehended by the spirit of the invention as described above, and the scope of the claims set out below. | There is provided a hydrogen storage system having one or more hydrogen storage containers disposed in a confined area with a vent line extending from the one or more storage containers to a location outside of the confined area. One or more sensors are disposed in the confined area for detecting one or more pre-determined unsafe conditions relating to the storage of hydrogen in the contained area and at least one actuator is provided for actuating an operable valve of the vent line to release the hydrogen from the hydrogen storage container to a location outside the confined area at a pre-determined release rate in response to a signal from the sensor indicating an unsafe condition. A power system incorporating a hydrogen storage system as described above is also provided. | 5 |
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of co-pending Ser. No. 627,149 filed July 2, 1984 now abandoned.
The invention relates to spacer members positioned on transmission gear shafts for axially locating gears and bearings. The majority of standard or manually shifted transmissions are internally lubricated by "splash and spray" oil, whereby rotating members within the transmission housing extend into an oil sump at the bottom of the transmission housing and disperse oil over the internals of the transmission. Numerous efforts have been made to achieve satisfactory oil dispersions within the transmission housing; one of the more noteworthy being the use of troughs which receive oil thrown randomly for redirecting same to specific locations within the housing. One particular location of critical importance, for example, is the transmission pocket bearing. Another of such locations is the reverse idler shaft which is typically non-rotatable, but carries a reverse idler gear rotatable thereabout on needle bearings interposed between gear and shaft members. Typically, two such sets of needle bearings are utilized to support the rotation of the reverse idler gear. A spacer member is positioned between the sets of needle bearings to first axially locate the bearings, and then to insure proper rotational position of the bearings during operation. Typical spacers are generally tubular in design, and operate only to hold the bearings apart, providing no facilitation of lubrication of the bearings.
SUMMARY OF THE INVENTION
The transmission gear shaft spacer disclosed herein provides a system whereby a flow of splash and spray oil along the shaft between the bearings is facilitated. In a preferred form, the spacer has squared ends which engage a pair of bearings supporting a rotatable reverse idler gear on a non-rotatable shaft. The spacer defines a helicoidal body of an open coil configuration, the squared ends providing radially uniform support surfaces resiliently disposed between the bearings. In a preferred form the helicoidal body is of a non-heat treated high carbon steel.
A second embodiment of a transmission gear shaft spacer defines a helicoidal body of a closed coil configuration disposed tightly between a pair of gears radially fixed to a gear shaft. The spacer provides axial positioning of the gears with respect to one another. The ends of the spacer are also squared in the second preferred form.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of a transmission which employs two alternate preferred embodiments of the spacer of the present invention.
FIG. 2 is an isolated side view, partly in section and in a free standing mode, of one of the preferred embodiments shown in FIG. 1.
FIG. 3 is a side view, also in a free standing mode, of the other preferred embodiment shown in FIG. 1.
FIG. 4 is a perspective view of yet another embodiment of the spacer of the present invention for preferred use in a transmission which utilizes helical gears, as opposed to spur gears.
FIG. 5 is an isolated side view of the spacer of FIG. 4.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring initially to FIG. 1, a sectional view of a transmission 10 includes two separate alternate embodiments of spacers made in accordance with this invention at 20 and 30, respectively. The transmission 10 embodies a relatively standard configuration of manually shifted gears, the gears positioned on a mainshaft 8, a countershaft 14 and a non-rotatable reverse idler shaft 12. Each of the two spacers circumferentially encases a portion of a transmission gear shaft. The spacer 20 is of an open coil configuration, and circumferentially encases the reverse idler shaft 12, while the closed coil spacer 30 encases the countershaft 14.
The open coil spacer 20 is axially interposed on the reverse idler shaft 12 between a parallel set of bearings 16 and 18. In the preferred embodiment, the bearings are needle bearings, although the spacer of the invention described herein is suitable for use with other types or styles of bearings as well. The bearings 16 and 18 support a reverse idler gear 22, for rotation thereof about the reverse idler shaft 12 on the bearings 16 and 18.
Referring now particularly to FIG. 2, the open coil spacer 20 defines a helicoidally shaped body portion 24, and has first and second squared ends 26 and 28, respectively. The squared ends 26 and 28 provide for radially uniform resilient support surfaces for contact with opposing inner ends 36 and 38 of respective bearings 16 and 18. In the preferred embodiment, the shaft will have an outside diameter slightly less than the inside diameter of the spacer. To the extent that the spacer is situated between the bearings 16 and 18, it will tend to rotate about the idler shaft 12 by virtue of friction drag forces imposed on the spacer ends 26 and 28 during rotation of the bearing inner ends 36 and 38 about the shaft 12. Thus the needle bearings 16 and 18 will frictionally cause the spacer 20 to rotate about the stationary reverse idler shaft 12. The resultant rotational movement of the helicoidal body portion 24 of the spacer 20 will produce an axial oil movement along the shaft 12 to facilitate lubrication of the needle bearings 16 and 18, which are not exposed directly to the splash and spray oil environment within the transmission 10.
It should be noted that the open coil spacer 20 may be disposed between the bearings 16 and 18 under a slight load; thus under a pre-loaded condition. It is suggested that the latter would insure continuous rotational movement of the spacer with the bearings about the non-rotating shaft 12. On the other hand, the spacer will move with the bearings without such pre-load, and even if there is slight axial floating of the spacer between the bearings by virtue of viscous drag forces imposed on the spacer due to surface tension of the oil.
An alternate preferred embodiment of the spacer of the present invention defines a closed coil as shown at 30 in FIG. 3. The spacer 30, however, is positioned (see FIG. 1) between a pair of gears 32 and 34 located on the countershaft 14. The gears 32 and 34 are keyed radially to the shaft 14, and the spacer insures the axial position of the gears with respect to one another on the shaft. Similarly to the ends 26 and 28 of the spacer 20, the ends 26' and 28' of the spacer 30 are squared for establishing a radially uniform support surface for contact with each of the gears. In this case, however, the contact is not resilient as there is no need for preloading of the sides of the gears 32 and 34.
It will be appreciated by those skilled in the art that the countershaft 14 is a rotatable shaft, and as a result will rotate the spacer member 30. The member 30 is fully exposed to the splash and spray oil environment within the transmission body. Those skilled in the art will appreciate the fact that the helicoidal body portion 24' of the spacer 30 will tend to cause oil slung away from the spacer to have a slight axial, as opposed to fully radial, component. As a result, the closed coil spacer 30 may be employed to enhance the oil dispersion within the transmission body by distributing the oil in a more desirable spray pattern. Again, in a preferred form, the spacer 30 is made of non-heat treated high carbon spring steel.
An alternate preferred form of the closed coil spacer 30 is a closed coil spacer 40 as shown in FIGS. 4 and 5. The spacer 40 has a square cross-section, and is desirable for use in transmission gear systems utilizing helical gears, as opposed to spur gears. Helical gears present end thrust loading problems due to the nature of the thrust loads imparted between the gears. Hence helical gears involve forces which have axial components resulting in axial thrust loads. The result is that the spacer members between such gears are subject to relatively high compressive axial loads, and under such conditions, the adjacent individual coils of the round cross-sectional spacer 30 of FIG. 3 tend to cam up over themselves and collapse when employed with helical gears of the type 32' and 34' as shown in FIG. 4. By contrast, the adjacent coils of the square cross-section spacer 40 of FIG. 5 will not "cam up" and will instead tend to transmit axial thrust forces uniformly between individual coils.
The problem is particularly exacerbated by the radial expansion to which the spacer element is subjected during normal rotation speeds of the counter-shaft. The counter-shaft will typically reach speeds of up to approximately 1800 revolutions per minute, and at times may momentarily reach even higher speeds.
FIG. 4 depicts the closed coil spacer 40 as being nested between helical gears 32' and 34'. The latter helical gears are counterparts of spur gears 32 and 34 of FIG. 1. In addition, the counter-shaft 14' of FIG. 4 is a counterpart of the counter-shaft 14 of FIG. 1.
FIG. 5 shows the square cross-section 42 of the closed coil spacer 40, as well as the nature of the squared ends 44 and 46 of the spacer 40. Ideally, the spacer ends 44 and 46 parallel each other, and each is perpendicular to the longitudinal axis a--a of the spacer.
Although only four preferred embodiments of the spacer of the present invention have been described and shown herein, there are many variations of the invention which are envisioned to fall within the scope of the following apended claims. | An improved spacer for a transmission gear shaft facilitates axial locations of pairs of gears or bearings along the shaft. In a preferred form the spacer comprises an open coil member which defines a helicoidal body portion resiliently disposed between a pair of bearings. In addition to axially locating the bearings relative to one another, the helicoidal body portion facilitates the flow of splash and spray oil along the shaft between the bearings. In the same preferred form, the spacer is made of a non-heat treated high carbon spring steel. | 5 |
FIELD OF THE INVENTION
The present invention relates to a wiper system for an automobile and more particularly, to an active wiper system which secures a good front visual range by changing the track of the wiper blade of a passenger's side and positioning pertinently the wiper blade in each range of the track, thus preventing rainwater wiped by the wiper blade of a passenger's side from dropping down to the front of a driver's side while driving in the rain.
BACKGROUND OF THE INVENTION
Generally, the conventional wiper system used for wiping off rainwater on the windshield glass in order to ensure visibility of a driver is defective in that the rainwater wiped by the wiper blade of a passenger's side drops down at a time onto windshield glass of a driver. Thus, the visibility of a driver is considerably restricted as shown in FIG. 1 . Especially, while driving in a heavy rain, such a conventional wiper system puts a driver in danger due to limited visibility.
SUMMARY OF THE INVENTION
Accordingly, in order to be free from the above-mentioned problem occurring in the conventional wiper system, an object of the present invention is to provide the active wiper system for an automobile which secures a good front visual range by changing the track of the wiper blade of a passenger's side and positioning pertinently the wiper blade in each range of the track, thus preventing rainwater wiped by the wiper blade of a passenger's side from dropping down to the front of a driver's side while driving in the rain.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a general wiper system.
FIG. 2 is an exploded view showing the components of the active wiper system in accordance with the present invention.
FIG. 3 is a perspective view of the active wiper system in accordance with the present invention.
FIGS. 4 a - 4 b are sectional views showing the operation of an active wiper system in accordance with the present invention wherein FIG. 4 a is a sectional view of the active wiper system just before the wiper blade is reversed to move up pivotally; and FIG. 4 b is a sectional view of the active wiper system just before the wiper blade is reversed to move down pivotally.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described in detail with reference to the accompanying drawings as set forth hereunder.
The active wiper system of the present invention comprises a pivot shaft 14 , a link member 18 , a slider 20 , and a rail 21 .
The present invention is characterized in that (i) the pivot shaft 14 capable of moving vertically with elastic supporting of spring 13 is inserted into a body member 12 and connected with the lower end of wiper arm/blade 11 of a passenger's side; (ii) the linkage 18 is connected perpendicularly to the shaft 14 at the lower end of the shaft 14 and supported by the stopper 16 which is fixed on a wiper rod 15 ; (iii) the slider 20 is sliding between an opening 19 disposed in the link member 18 so as to move whole part of the link member 18 vertically; and (iv) the rail 21 leads the movement of the slider 20 .
The present invention is also characterized in that the slider 20 comprises a stay 22 disposed in the opening 19 of the link member 18 and a roller 25 which is installed at the lower end of the stay 22 and rolls on the rail 21 .
The present invention is further characterized in that the rail 21 on which the guide groove 24 is formed has a rising curvilinear section at the rear portion of the rail 21 .
The present invention is further characterized in that the stopper 16 has a ball-connection with the wiper rod 15 by means of the ball fixed to the lower end of the stopper 16 .
The present invention is further characterized in that the stay 22 is elastically supported by two stay springs 23 which are mounted at both ends of the stay 22 .
The present invention is described in more detail hereinafter.
FIG. 2 represents an exploded view showing the components of the active wiper system in accordance with the present invention and FIG. 3 represents a perspective view of the active wiper system.
The shaft is designated as reference numeral 14 .
As shown in FIGS. 2 and 3, the shaft 14 is inserted into the body member 12 , wherein the upper end of the shaft 14 is integrally connected to the lower end of the wiper are/blade 11 and the lower end is perpendicularly integrated with the link member 18 , thus the shaft 14 moves with the wiper arm/blade 11 in the upward and downward directions depending on the movement of the link member 18 . In particular, the restoring force of a rod spring 13 mounted between the linkage 18 and the shaft 14 allows the shaft 14 to return to its original position.
The link member is designated as reference numeral 18 .
The link member 18 as a power-transmitting member includes the opening 19 in the middle of the link member 18 , of which one end is perpendicularly integrated with the lower portion of the shaft 14 and the other end is connected on the wiper rod 15 by a means of the stopper 16 . The link member 18 moves vertically by the movement of the slider 21 mounted in the opening 19 in the middle of the link member 18 , thus allowing up-and-down movement of the wiper arm/blade 11 including the shaft 14 . The stopper 16 accepts sufficiently all the movements of the link member 18 by using the ball 17 mounted under the stopper 16 .
The slider is designated as reference numeral 20 .
The slider 20 consists of the stay 22 which is disposed in the opening 19 of the link member 18 and the roller 25 which is installed at the lower end of the stay 22 , wherein the stay 22 is supported for elastic movement by two stay springs 23 mounted at both ends of the stay 22 .
The rail is designated as reference numeral 21 .
The rail 21 for guiding the roller 25 is fixed on the wiper rod 15 . The guide groove 24 is formed on the rail 21 with rapid rising curvilinear section at the rear portion. As the roller 25 rides along with the rising curvilinear section of the rail 21 , the link member 18 and the shaft 14 begin to simultaneously rise. Therefore, the wiper arm/blade 11 can be detached from the windshield glass. In addition, it is preferred that the length of the rising curvilinear section should not exceed one third of full length of the rail 21 .
The operational effect of the active wiper system in accordance with the present invention will be delineated in detail as follows.
FIG. 4 a is a sectional view showing the operation of the active wiper system just before the wiper arm/blade 11 moves. In this stage, the wiper arm/blade 11 and the shaft 14 are placed at the normal position where the wiper are/blade 11 is attached closer to the windshield glass surface due to the elastic force of the rod spring 13 and the roller 25 of the slide 20 is also on the flat section of the rail 21 .
When the roller 25 of the slider 20 in the link member 18 rolls along with the guide groove 24 of the rail 21 from the beginning portion to two third of the rail 21 , the wiper arm/blade 11 can wipe off rainwater on the surface of the windshield glass because the roller 25 is on the flat section of the rail 21 . On the other hand when the roller 25 starts to move up to the rising curvilinear section of the rail 21 , the wiper arm/blade 11 is detached from the windshield glass.
That is, when the roller 25 of the slider 20 starts to move along with the end portion of the guide groove 24 where is the rising curvilinear portion, the wiper arm/blade 11 is also moving as detached from the windshield glass. Therefore, the rainwater wiped falls down before it reaches the front of a driver's side. This active wiper system, thus, provides the large and good visual range for the driver while driving in the rain.
Reversely, the wiper arm/blade 11 begins its descent to downside with dectached form when the roller 25 rolls down the rising curvilinear portion of the rail 21 . Thereafter, since the roller 25 rolls down the flat portion, it finishes its descent with closely attached form, resulting in clear and wide visual range for the driver.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. | The present invention relates to a wiper system for an automobile and more particularly, to an active wiper system which secures a good front visual range by changing the track of the wiper blade of a passenger's side and positioning pertinently the wiper blade in each range of the track, thus preventing rainwater wiped by the wiper blade of a passenger's side from dropping down to the front of a driver's side while driving in the rain. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application Ser. No. 61/658,061 titled “METHOD OF IN VITRO DIFFERENTIATION OF MOTOR NEURON PROGENITORS (MNPS) FROM HUMAN INDUCED PLURIPOTENT STEM CELLS AND CRYOPRESERVATION OF MNPS,” filed on Jun. 11, 2012, which is incorporated herein, in its entirety, by this reference.
FIELD OF THE INVENTION
[0002] The present invention relates to producing motor neuron progenitors (MNPs) from human induced pluripotent stem cell (iPSC) lines and human embryonic stem cell (hESC) lines. More particularly, this invention provides a method of producing greater than 75-90% purity and functional MNPs from various hESC lines and iPSC lines. The present invention also relates to cryopreserving MNPs. More particularly, this invention provides a method of cryopreserving MNPs that allows more than 90% recovery of highly viable and functional cells post-thawing.
BACKGROUND OF THE INVENTION
[0003] Neurons may be classified based on their structure and function. Structural classification is based on the number of processes extending from the neuronal cell body. In contrast, functional classification is based on the direction in which the neuron transmits nerve impulses. Motor neurons (MN) are efferent neurons that convey nerve impulses from the brain and spinal cord (that is, away from the central nervous system) to effectors (which may be either muscles or glands). The satellite-shaped cell body of the MN is connected to a single, long axon (which forms a neuromuscular junction with effectors) and several shorter dendrites projecting out of the cell body. Neurology and drug discovery laboratories have traditionally relied on rodent models for the study of MN function and associated diseases such as amyotrophic lateral sclerosis (also known as ALS or Lou Gehrig's disease) and spinal muscular atrophy. However, recent advances in stem cell research, such as the availability of hESCs and iPSCs, offer the opportunity to develop human models for the study of MNs and associated diseases.
[0004] Current MN differentiation protocols for hESCs and iPSCs rely on embryoid body formation and directed differentiation by stromal feeder cell co-culture or by selective survival conditions. Current methods for generating MNs (Hu et al. 2010; Karumbayaram et al. 2009, Bouniting et al. 2011; US 2011/0091927A1) Nature Biotechnology 29:279-286 2011 are similar to each other and, in general, all include generating embryoid bodies or aggregates from either hESC or iPSCs in the presence of retinoic acid and induction of the sonic hedgehog pathway. The aggregates are then maintained in culture with neurotrophic factors to promote MN survival. Okano and Shimazaki (U.S. Pat. No. 7,294,510) have described another method of differentiating of ES cell to neural stem cell using noggin to form embryoid bodies. Subsequently, the embryoid bodies are subjected to suspension culture in the presence of fibroblast growth factor and a sonic hedgehog protein without using retinoic acid to induce formation of neural stem cells. Finally, neural stem cells are differentiating into only motor neurons and GABAeric neurons without glia cells contamination. Other directed differentiation methods without embryoid body/aggregate formation (Karumbayaram et al. 2009) Stem Cells; 27(4) 806-811; 2009 showed successful generation MN at very low efficiency.
[0005] Current methods are complicated, lengthy, and result in low yields. Zhang and Li (U.S. Pat. No. 7,588,937) have also described a method of producing spinal motor neuron by using hESCs growing on mouse embryonic fibroblast feeders as starting point. These cells are formed embryoid bodies in suspension and continue to differentiate in rosettes structure using retinoic acid and retinoic acid together with sonic hedgehog. The yield MNPs from this method was in ˜20-50% purity. U.S. Pat. No. 8,137,971 discloses the most efficient method available to date to make MNs from hESCs. However, this method cultures hESC in feeder cell-free conditions. It is difficult to consistently achieve sufficient neural induction to efficiently produce MNPs. Furthermore, this method only works with one hESC line and produces MNPs at approximately 65% purity. Therefore, this process is not as efficient as indicated. Other studies (Hu et al. 2010; Karumbayaram et al. 2009, Bouniting et al. 2011; PNAS 107(9) 4335-4340; 2010; Stem Cells; 27(4) 806-811; 2009; Nature Biotechnology 29:279-286 2011 have successfully demonstrated that MNPs can be generated from a number of iPSC lines; however, these studies are highly variable and inefficient. Currently, there is no optimized process to reproducibly generate MNPs from iPSCs that is simple, efficient, and scalable. Therefore, there is a need for a simple and efficient method of producing MNPs from various lines of hESCs and iPSCs. In addition, there is a need for a method of producing MNPs that is scalable and reproducible for downstream therapeutic applications.
[0006] In addition, there is no method available for the cryopreservation of MNPs with efficient recovery. The current method of cryopreservation for MNPs uses high concentration of DMSO with a serum free basal medium supplemented with B27 and freezing is performed by using a freezing container such as Nalgene® “Mr. Frosty” (available through Sigma-Aldrich) in the presence of isopropanol and mechanical −80° C. freezer which provides a slow cooling rate of about −1° C./min to −80° C. and subsequent plunging in liquid nitrogen. Although, this simple freezing method would work for cryopreserving of MNPs and other cell types, the recovery of MNPs after thawing is not always consistent and never reaches >90% cell viability. This could be due to the fact that the freezing container has no control for the cooling rate. This cooling rate is depending on the mechanical −80 C freezer's ability to keep its temperature. Furthermore, it also depends on the location within the freezer since there is temperature variability within a freezer shelf and shelf locations. Therefore, there is also a need for a method of cryopreserving MNPs that allows the frozen cells to be thawed with consistent high viability and functionality.
SUMMARY OF THE INVENTION
[0007] Accordingly, an object of the present invention is to provide a method of producing MNPs from human pluripotent cells (including hESCs and iPSCs) that is simple, efficient, scalable, and reproducible.
[0008] A further object of this invention is to provide a method of cryopreserving MNPs that allows the frozen cells to be thawed with high viability and functionality.
[0009] A further object of this invention is to provide methods applicable to pluripotent stem cells in general, and induced pluripotent stem cells in particular.
[0010] A further object of this invention is to provide universal methods applicable regardless of cell source.
[0011] A further object of this invention is to provide for higher robustness and viability of MNPs.
[0012] A further object of this invention is to provide for greater than 90% viability of recovered MNPs.
[0013] A further object of this invention is to reduce the clumping of the cells.
[0014] A further object of this invention is to provide a method of cryopreserving MNPs that allows the frozen cells to be thawed with high recovery.
[0015] A further object of this invention is provide a method including the use of mouse embryonic fibroblast (MEF) feeder cells to culture the iPSCs and hESCs
[0016] In one representative embodiment, a method is provided for producing MNPs in vitro by harvesting hESCs or iPSC, which have been grown on mouse embryonic fibroblasts for at least 6-7 days, and these undifferentiated hESCs or iPSCs are neuralized by plating and culturing in ultra-low-adherence flasks containing a serum-free motor neuron induction medium for about 5 days. The induction medium is a classical medium containing growth factor, non-essential amino acids, L-glutamine, insulin, transferrin, selenium and B27 and is supplemented with bFGF and retinoic acid to generate spheres. The cultured spheres are ventralized by using an induction medium supplemented with low concentration of bFGF for about 10 days to promote formation of neurospheres. The suspension cultured neurospheres are mechanically dissociated into smaller spheres and expanded on an adherent surface for about 5 days as neural rosettes or early stage MNP. Thereafter, the adherent early stage MNPs are dissociated using trypsin solution and are transferred to gelatin-coated flasks containing induction medium to further enrich MNP cells. The non-adherent cells are collected from the gelatin-coated flasks, re-plated as adherent cells in matrix-coated flasks, such as Matrigel®, containing induction medium, and repeatedly cultured and re-fed with induction medium for about 5-6 days. Then, the adherent late stage MNPs are harvested from the matrix-coated flasks using trypsin solution. The resulting cell suspension is transferred to gelatin-coated flasks to further enrich MNP cells and remove contaminant cells. Non-adherent MNPs from the gelatin-coated flasks are collected, and large cell clumps are sedimented in a conical tube. MNPs are collected from the supernatant in the conical tube following the sedimentation of the large cell clumps can be stored as cryopreserved MNPs.
[0017] In an aspect of one representative embodiment, the concentration of bFGF is used at 10 ng/ml in the induction medium for the first day of plating of undifferentiated hESC or iPSC through day 7 of culture, and bFGF concentration is decreased to 5 ng/ml on day 8 of culture until harvesting of the MNPs.
[0018] In an aspect of one representative embodiment, the concentration of retinoic acid is used at 10 μM from day 1 through day 7 culture.
[0019] In another representative embodiment, the harvested MNPs-containing supernatant is centrifuged and the resulting cell pellet of MNPs is re-suspended in a cold protein-free and serum-free freezing medium pre-formulated with DMSO in a cryovial. An example of such freezing media can include CRYOSTORE® CS10 solution, by BioLife of Seattle, Wash. By way of example, 10% DMSO can also be used and optimized to freeze cells. The cryovial is transferred to a controlled rate freezer and subjected to programmed freezing process. Thereafter, the cryovial is transferred from the controlled rate freezer to a liquid nitrogen Dewar for long term storage.
[0020] Typically, upon reconstitution of cryopreserved stem, cells no more than 70% of the cells are viable post-thaw. It is a further aspect of the cryopreservation of the MNPs as disclosed herein that, upon reconstitution, 70% or greater and specifically 90% or greater of the cells are viable post thaw.
[0021] These and other objects are achieved in the present invention. The present invention overcomes a major disadvantage of current methods of producing MNPs for therapeutic applications by providing a simple, highly efficient, scalable, and reproducible method of differentiating MNPs from various lines of hESCs and iPSCs. One invention disclosed herein is the use of mouse embryonic fibroblast (MEF) feeder cells to culture the iPSCs and hESCs. hESCs were originally derived and cultured on MEF layers which permit continuous growth of hESCs in an undifferentiated stage (Amit et al 2003; Biology of Reprod 68:2150-2156). In vitro, the hESCs tended to differentiate when cultured in the absence of MEF feeder layers (Thomson et al 1998 Science 282 (5391) 1145-7). Feeder cells have also been derived from several human cell types such as human foreskin fibroblasts or adult Fallopian type epithelial cells (Amit et al 2003 Biology of Reproduct 22(5) 1231-8; Richard et al 2002 Nat Biotech 20(9) 933-6; Richards et al 2003. Stem Cells 21(5)546-56; Hovatta et al 2003. Human Reproduction 18(7) 1404-9; Choo et al 2004. Biotech and Bioengineering 88(3) 321-33). However, the ability of different types of human feeder cells to support the undifferentiated growth of hESCs varies (Richards et al 2003 Stem Cells 21(5)546-56; Eiselleova et al 2008. J of Devel Biol 52(4) 353-63). Activin A and basic fibroblast growth factor (bFGF) are key factors in maintenance the pluripotent state of stem cells (Eiselleova et al 2008. J of Devel Biol 52(4) 353-6315; Xiao et al 2006. Stem Cells 24(6) 1476-86). Mouse feeder cells express more Activin A than human feeder cells, but they do not express bFGF like human feeder cells (Eiselleova et al 2008. J of Devel Biol 52(4) 353-6315). When compared to human feeder cells, MEFs seem to support better the undifferentiated growth of some hESC lines, whereas more spontaneous differentiation and a lower proportion of SSEA3 positive cells can be observed with human feeder cells (Eiselleova et al 2008. J of Devel Biol 52(4) 353-6315). Cultured feeder cells secrets numerous of uncharacterized growth factors, cytokines, extracellular matrix (ECM) components such as proteoglycans, fibronectin, various types of collagen, nidogen, and laminin. These aforementioned ECM proteins, growth factors and cytokines secreted by feeder cells provide hESC/iPSCs a scaffold for hESC/iPSCs to anchor and provide the signals to proliferate and maintain their pluripotency. The present inventors have unexpectedly found that using feeder cells maintains the pluripotent state of the iPSCs and hESCs such that these cells are primed in better conditions for subsequent neuralization and ventralization steps of motor neuron differentiation process. This important change in methodology over the currently available art improves neuralization potency and results in a functional and more homogenous population of MNPs. In addition, the method of the present invention can be used for a variety of iPSC and hESC lines with consistent yield of high purity MNPs. Accordingly, the method of the present invention has significant improvements over the current technology that requires culturing of hESCs under feeder cell-free conditions such as matrix gel (U.S. Pat. No. 8,137,971).
[0022] The present invention also introduces a highly efficient freezing method for MNPs that includes the use of chemically-defined cryoprotectants and a controlled rate freezer to improve cell recovery after thawing from long term storage. The latter improvement over the prior art allows the long term storage of MNPs, which provides greater experimental flexibility in downstream applications. Cryopreservation during the differentiation process introduces efficiencies for the commercial manufacture of MNPs.
[0023] There has thus been outlined, rather broadly, features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described further hereinafter. Indeed, 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.
[0024] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0025] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other methods, systems, kits, and compositions for carrying out the several purposes of the present invention. It is important, therefore, that equivalent constructions insofar as they do not depart from the spirit and scope of the present invention, are included in the present invention.
[0026] The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 illustrates an MNP manufacturing process.
[0028] FIGS. 2A-E illustrates: (A) cultured iPSCs on MEFs feeder; (B) neurospheres in suspension culture condition after caudalization on day 8; (C) neurospheres in suspension culture after ventralization on day 18; (D) Plated neurospheres on adherent substrate showing migration of the early MN progenitors; and (E) expansion of the early MN progenitors after first purification.
[0029] FIGS. 3A-C provide images of characterization of MNPs before cryopreservation on day 28: (A) MNP specific marker Islet1; (B) MNP specific marker HB9; and (C) neurofilament protein (Tuj1).
[0030] FIGS. 4A-C illustrate images of MN progenitors after cryopreservation and re-plated on PDL/laminin coated surface on day 3 after thawing: (A) Thawed MN progenitors after cryopreservation with branched morphology; (B) neurofilaments (Tuj1, green) and GFAP (red) and DAPI nuclear staining (blue); and (C) HB9 (red) transcription factor makers for MN progenitor and neurofilament (Tuj1, green).
[0031] FIG. 5 illustrates maturation of MNP in the absence and presence of B27 in laminin coating step.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Provided herein are methods for the production of MNPs from various lines of hESCs and iPSCs.
[0033] Reference will now be made in detail to representative embodiments of the invention, examples of which are illustrated in the accompanying drawings.
Listing of Materials and Equipment
[0034] The following is a list of materials, reagents, and equipment used in the present invention. One skilled in the art understands that the materials, reagents, and equipment of the present invention are provided as examples only and that similarly functioning materials, reagents, and equipment can be substituted for those in the list without undue experimentation. Equipment list: laminar flow biosafety cabinet class II, centrifuge, water bath, incubator, refrigerator, first freezer, second freezer, pipet aid or pipet ball, multi-channel pipettors, multi-channel aspirator, microscope, assorted pipettors and pipet tips, hemocytometer, NucleoCounter® (Lonza), Cell scrappers (Corning 3010), T-25 flasks (Corning 430639), T-75 flasks (Corning 430641), T-75 ultra-low adherence flasks (Corning 3814), 15 ml centrifuge tubes (BD Falcon 352097), 50 ml centrifuge tubes (BD Falcon 352098), aspirating pipets (BD Falcon 357558), assorted serological pipets (BD Falcon 356543, 357551, 357525, 357550), 50 ml Steriflip® tubes (Millipore SCGP00525), 50 ml reagent reservoirs, precision balance, assorted Nalgene® bottles (Fisher Scientific 339072,2923145, 0292500A, and 0292500B), cryovials (Corning 430659), Technicloth® Wipes, Trypan blue solution, 70% Isopropanol, 2% Bacdown® (Fisher Scientific 04-355-13), water for cell culture (Lonza), hESC medium, MNP basal medium, MNP Plating medium, MNP maintenance medium, 10 μg/ml bFGF stock solution (BioSource PHG0263 (1 mg powder)), Retinoic acid (Sigma-Aldrich R2625), TrypLE® solution (Gibco 12605-010) Recombinant porcine tryp sin formulated in DPBS and 1 mM EDTA, PBS: Phosphate buffer saline, low osmolality medium without w/o L-glutamine or Hepes buffer for hESCs and iPSCs, Poly-D-lysine (Sigma-Aldrich P7405-5MG), Laminin solution (Roche 11243217001), DMEM High Glucose (Thermo Fisher SH3008101), Collagenase type IV lyophilized (Gibco 17104-019), an optimized, cGMP produced, protein-free and serum-free freezing medium pre-formulated with DMSO, laminin working solution, Poly-D-Lysine stock solution, Poly-D-lysine working solution, collagenase IV working solution and retinoic acid stock solution.
[0035] In at least one embodiment, the water bath is about 37° C.
[0036] In at least one embodiment the incubator is capable of maintaining 37° C.±2° C. with a 5%±2% CO 2 and humidified atmosphere.
[0037] In at least one embodiment the refrigerator is capable of maintaining about 2 to 8° C.
[0038] In at least one embodiment the first freezer is capable of maintaining about −20 to −30° C.
[0039] In at least one embodiment the second freezer is capable of maintaining about −78 to −82° C.
[0040] In at least one embodiment, the hESC medium is Knockout DMEM supplemented with 20% KOSR, glutamax, non-essential amino acids and bFGF and beta mercaptoethanol, MNP Induction medium such as a 50:50 mixture of classical DMEM high glucose and DMEM/F12 supplemented with insulin, transferrin, selenium, glutamine, magnesium chloride and B27 (NSF1). Once mixed, the medium was used for no more than 14 days.
[0041] In at least one embodiment, the MNP basal medium is a classical DMEM high glucose supplemented with B27 (NSF1), non-essential amino acids, insulin, transferrin, selenium, hepes, magnesium chloride, zinc sulfate, and copper sulfate with or without L-glutamine. Once mixed, the medium was used for no more than 14 days.
[0042] In at least one embodiment, the MNP Plating medium is MNP basal medium supplemented with B27 (NSF1) and L-glutamine.
[0043] In at least one embodiment, the MNP maintenance medium is MNP basal medium supplemented with B27 (NSF1).
[0044] In at least one embodiment, low osmolity medium is KnockOut DMEM/F12 (Gibco 12660-012).
[0045] In at least one embodiment, the an optimized, cGMP produced, protein-free and serum-free freezing medium pre-formulated with DMSO is CryoStor® CS10 (BioLife® Solution 210102).
[0046] In at least one embodiment, the laminin working solution is stock laminin solution (500 μg/ml) diluted by mixing 300 μl of stock laminin solution in 10 ml of MNP basal medium (15 μg/ml).
[0047] In at least one embodiment, ten sterile cryovials were labeled and stored at −20° C., 30 minutes prior to use. Five mg of Poly-D-Lysine powder from Sigma was rehydrated in 10 ml of water for cell culture for at least 30 minutes in the laminar flow hood. The rehydrated poly-D-lysine stock solution (500 μg/ml) was aliquoted at 1 ml/vial and the aliquots were stored at −20° C. until required for coating.
[0048] In at least one embodiment, a 1 ml aliquot of the stock Poly-D-Lysine solution was thawed and diluted by mixing it in 9 ml of PBS. The working solution of poly-D-lysine (50 μg/ml) was used for coating.
[0049] In at least one embodiment, collagenase IV working solution is 0.1 ml/cm2 of 1 mg/mL collagenase solution (7.5 ml per T-75 flask and 2.5 ml per T-25 flask). An appropriate amount of milligrams of collagenase powder was weighed out using the precision balance by multiplying by 2 the calculated volume of collagenase solution. The weighed out collagenase was transferred into a 50 ml tube and the calculated volume of low osmolarity DMEM/F12 medium, e.g. Knockout™ DMEM/F12 from Life Technologies, was added. The solution was mixed thoroughly by swirling until all the collagenase was completely dissolved, and was filtered through a 0.22 μm filter before use. The solution was stored at 4° C. and used within one week.
[0050] In at least one embodiment, care was taken while preparing retinoic acid aliquots to avoid exposing the materials to light for too long. In one embodiment, aliquots were prepared in the laminar flow hood as quickly as possible with the hood lights turned off. The 100 mg vial of retinoic acid was disinfected and placed it in the laminar flow hood. The top of the glass vial was broken off carefully and discarded into a sharps bin. Using a 1 ml syringe filter, 1 ml of dimethylsulfoxide (DMSO) solution was added to dissolve the retinoic acid powder. The mixture was transferred into a 50 ml tube and the glass vial was rinsed three times with 1 ml DMSO each rinse. The rinses were transferred to the 50 ml tube containing the retinoic acid mixture. Another 12.6 ml of DMSO were added to the tube and mixed well by pipetting up and down several times. This made a stock solution of 20 mM retinoic acid. Using a 200 μl pipette, 100 μl aliquots of stock solution were made in 500 μl amber tubes and the tubes were placed immediately in a −80° C. freezer.
Example 1
Differentiation of hESCs
[0051] Materials and Experimental Design
[0052] Initiation of Motorneuron Differentiation Day 0
[0053] Human ESCs or iPSCs were co-cultured with MEF feeder cells with hESC growth medium (knockout DMEM/F12, 20% KSR, Glutamax, NEAA, BME and bFGF) on the T75 flask ( FIG. 2A ). hESCs were initiated when the cell density reached around 80% confluence. Spent medium from the T-75 flask was replaced with 30 ml of a 1:1 mixture of hESC medium and MNP induction medium supplemented with 10 ng/ml bFGF. After 24 hours, the hESCs/iPSCs colonies were dissociated using a collagenase solution (1 mg/ml) and the dissociated cells were suspended with MNP induction medium supplemented with 10 ng/ml bFGF and 10 μM of retinoic acid. The cell suspension then was transferred into an ultra-low-adherence T-75 flask.
[0054] Medium was gently replaced daily for 7 days without breaking cellular aggregates ( FIG. 2B ). Cell suspension along with the spent medium was transferred into a 50 ml conical tube. The cellular aggregates (spheres) were allowed to settle and the spent medium and cell debris were aspirated carefully without losing any spheres.
[0055] Starting from day 8, retinoic acid was removed from medium and bFGF concentration was reduced to 5 ng/mL. Numerous neurospheres were formed while some have the tendency to attach to other cells and form larger cellular spheres ( FIG. 2C ). Medium was replaced every other day until day 20 by using the same procedure but at a shorter sediment time to remove non-neurospheres.
[0056] On Day 20, the spheres along with the spent medium were transferred into a 50 ml conical tube. The spheres were allowed to sediment for about 30 seconds and the spent medium was aspirated. The spheres were resuspended in 5-7 ml fresh medium and they were sedimented for about 15-30 seconds while spent medium was aspirated. This washing step was repeated twice. The spheres were pipetted gently with a 10 ml serological pipet to break up the aggregates and were transferred to Matrigel®-coated T-75 flasks and distributed evenly prior to placing in the incubator.
[0057] Neurospheres were adhered to Matrigel®-coated surface, and the cells migration from spheres and cells with unipolar or bipolar extension could be observed ( FIG. 2D ). Medium was replaced every other day.
[0058] After 5 days, the cultures were dissociated with TrypLE solution. Once the cells were dissociated, to each T-75 flask, 15 ml of MNP induction medium supplemented with bFGF was added and the cell aggregates were triturated gently to break up the remaining spheres. The cell suspension was centrifuged for 3 minutes at 200×g. The cells were resuspended with 10 ml of fresh MNP induction medium supplemented with bFGF and the suspension was transferred into the gelatin-coated T-75 flask. The T-75 flask was incubated for 15 minutes at 37° C. undisturbed. After incubation, all the non-adherent cells were collected from the T-75 flask and transferred to another gelatin-coated T-75 flask. The T-75 flask was incubated for 15 minutes at 37° C. undisturbed. All the non-adherent cells were collected from the T-75 flask and the cell suspension was distributed evenly in the two Matrigel®-coated T-75 flasks (about 20 ml/T-75 flask) and one 4-well chamber slide pre-coated with Matrigel®. The seeded flasks and chamber were placed in the incubator.
[0059] Medium was replaced every other day. On Day 28, the slides were fixed by 4% paraformaldehyde and stained with neuronal marker Tuj1 and specific motor neuron makers including: Hb9, Islet1.
[0060] On Day 30, MNPs ( FIG. 2E ) were harvested by using the same methods as described in previous section of Day 25 MNP using trypLE and purified by using gelatin coated flasks to remove non MNP cells. MNPs were collected as non-adherent cells from gelatin coated flasks. Cell counts and viability were determined by using NucleoCounter.
[0061] Results
[0062] Generation of Motor neurons in vertebrate animal involves: neuralization of ectodermal cells, caudalization of the neuroectodermal cells and ventralization of the caudalized neural progenitors. FIG. 1 provides an overview of the MNP differentiation process. To initiate neuralization, a chemically defined formulation is introduced: 50:50 mixture of classical DMEM high glucose and DMEM/F12 supplemented with insulin, transferrin, selenium, glutamine, magnesium chloride and B27 (NSF1). Then the physical environment of the hES cells/iPSCs changed from adherent feeder cells to a non-adherent aggregates condition (suspension), the cell suspension was cultured for next 20 days in low adherent containers.
[0063] Caudalization and ventralization were induced by using retinoic acid (RA). Cellular aggregates are treated with RA from day 1 for 7 days. Following RA treatment, bFGF concentration was reduced to 5 ng/ml and frequency of medium changes was extended from daily feeding to 2-days feeding schedule. This could facilitate accumulation of autocrine factors from neural progenitors. Not to be bound by theory, it is believed the autocrine factors are important for motor neuron differentiation.
[0064] After neurospheres formation, the suspension was plated onto Matrigel®-coated surface for further expansion. During this time, the elongated cells with radial arrangements migrated from the spherical formations (rosettes) along with some flat cells would outgrow as well. Early MNPs could be purified by using negative adsorption on gelatin coated surface where contaminating cells adhered and MNPs were separated as non-adherent cells.
[0065] After expansion and purification, MNPs are characterized with neuronal marker and MNPs specific markers before cryopreservation. The results showed that on day 28, majority cells expressed HB9, Islet1 and Tuj1 ( FIG. 3 ). PSCs marker such as Oct4 and glial marker GFAP were not detectable. Expression of mesodermal marker SMA was very minimal.
Example 2
Harvest and Cryopreservation of Mnps
[0066] Materials and Experimental Design
[0067] On Day 30 or Day 31, four T-75 flasks were coated with 7 ml per flask of 0.1% gelatin solution and incubated for 30 minutes in the incubator. Approximately 150 ml of MNP induction medium were pre-warmed. The spent medium from the T-75 flasks was aspirated and the flasks were washed once with 15 ml of PBS each. Five ml of TrypLE solution were added and incubated 3-10 minutes. The flask was examined every 3 minutes until most cells were dissociated. Ten ml of MNP induction medium were added to each flask and the suspension was transferred into 50 ml conical tubes. Each T-75 flask was rinsed with an additional 10 ml of medium and the solution was transferred to the 50 ml tubes. The tubes were centrifuged at 200×g for 3 minutes at room temperature. The supernatant was aspirated and the cell pellet was resuspended in 20 ml of medium and the suspension was transferred into the gelatin-coated T-75 flasks (10 ml/flask). The conical tubes were rinsed with 4 ml of MNP induction medium and the solution was transferred to the gelatin-coated T-75 flask. The T-75 flask was incubated for 15 minutes at 37° C. undisturbed. After incubation, all the non-adherent cells were collected from the T-75 flask and transferred to another gelatin-coated T-75 flask, and the flask was gently rinsed with 3-5 ml medium, and the solution was transferred to the gelatin-coated T-75 flasks. The T-75 flasks were incubated for 15 minutes at 37° C. undisturbed. After incubation, all the non-adherent cells were collected from the T-75 flasks and transferred to the 50 ml tubes. The larger cell clumps were allowed to settle to the bottom of the tubes for 3 minutes. The supernatant (>95% of the solution) was transferred into a fresh tube and the cells were counted using a NucleoCounter®. The tubes were centrifuged at 200×g for 3-5 minutes at room temperature. The supernatant was aspirated and 10 ml of cold CryoStor® solution were slowly added to the cell pellet and the cell pellet was gently resuspended. About 100-200 μl of suspension were taken for counting again using NucleoCounter®. The remaining cell solution was put on ice while waiting for cell counts. The viable cell concentration was adjusted to 6 million/ml by adding more CryoStor® solution, and 1 ml suspension was aliquoted into each cryovial. A programmable controlled rate freezer was used to freeze MNPs using the following parameters. After the freezing cycle was completed, cryovials were transferred to liquid nitrogen Dewar immediately after the freezing program was completed
[0068] Results
[0069] Previous studies of cryopreservation of MNPs by typical method using a freezing container together with a −80° C. mechanical freezer showed inconsistent recovery after thawing and cell viability about 70-80%. The possible explanation is that cryoprotectant was not utilized and cooling rate might not be consistent due to a number of reasons such as location within the −80 C mechanical freezer. To improve recovery of MNP during cryopreservation process, cryoprotectants were examined together with controlled rate freezer to ensure the cooling rate was consistent. Several cryoprotectants such as trehalose, mannitol, and hetastarch were used in combination with DMSO and compared with CryoStor CS10 (Table 1). Cell counts prior to freezing were shown in Table 1 and all tested conditions had cell viability about 90% prior to freezing. Approximately 6×106 cells were frozen in each cryovial. All the cryovials were frozen by using a programmable controlled rate freezer with freezing parameters indicated in Table 2. After storing the cryopreserved MNPs under liquid nitrogen, cells were quickly thawed from liquid nitrogen storage by using a 37° C. water bath. Cell count was determined by Nucleocounter and viability was calculated. The results showed that CryotoR performed better than that of other tested conditions and cell viability was consistently greater than 85 percent after thawing (TABLE 3). Motor neuron markers such as Isl1 and HB9 expression of thawed MNP was normal ( FIG. 4B , FIG. 4C ) as compared with MNP that did not undergo freezing/thawing (Data not shown).
[0000]
TABLE 1
Testing freezing media for cryopreservation of MNPs.
Tested
Cell Counts
Viabil-
Condi-
pre- freezing
ity pre-
tions
Components
per mL
freezing
Control
MNP basal medium +
Viable: 6.18 × 10 6
92%
B27 and 10% DMSO
Total: 6.7 × 10 6
KOSR
MNP basal medium + 25%
Viable: 6.19 × 10 6
92.3%
KOSR + B27 and 10%
Total: 6.7 × 10 6
DMSO
Treha-
MNP basal medium + 5%
Viable: 7.1 × 10 6
93%
lose/
trehalose + 5% mannitol +
Total: 7.65 × 10 6
mannitol
B27 and 10% DMSO
Heta-
MNP basal medium + 6%
Viable: 5.98 × 10 6
93%
starch
hetastarch and 10% DMSO
Total: 6.4 × 10 6
CryoStor
Proprietary formulation
Viable: 5.72 × 10 6
95%
Total: 6 × 10 6
[0000]
TABLE 2
Freezing parameters for cryopreservation of MNP.
Conditions
Temperature
Rate
1. Holding
5° C.
2. Cooling
−5-10° C.
0.5-2° C./min
3. Ramping
−35-50° C.
10-30° C./min
4. Ramping
−10-20° C.
5-20° C./min
5. Cooling
−30-50° C.
0.5-2° C./min
6. Ramping
−70-90° C.
5-15° C./min
7. Holding
−70-90° C.
Example 3
Plating of Motor Neuron
[0070] Materials and Experimental Design
[0071] Plate Coating
[0072] Each 96 well plate required 10 ml of poly-D-lysine working solution (50 μg/ml). The required amount of poly-D-lysine working solution was transferred into a sterile reagent reservoir. Using a multi-channel pipettor, each well of a 96 well plate was coated with 100 μl of poly-D-lysine working solution and the plates were placed in the incubator overnight. After incubation, the poly-D-lysine solution was aspirated using a multi-channel aspirator. The wells were rinsed twice with 100 μl per well of PBS. The plates were dried in the laminar flow hood with the lids off for at least 1 hour and were ready for laminin coating. The required amount of laminin working solution (15 μg/ml) was prepared in MNP basal medium (without B27/NSF1). Using a multi-channel pipettor, 75 μl of laminin working solution were added per well. The plates were incubated at 37° C. for at least one hour but no longer than six hours. The laminin solution was aspirated when the cells were ready to plate. The wells were rinsed with 100 μl of medium per well once prior to plating the cells.
[0073] Thawing MNPs
[0074] One ampule was thawed in a 37° C. water bath. To insure a good recovery of the cells from cryoperservation, the cell suspensions were thawed quickly but not allowed to sit at or warm above at 37° C. Immediately after the suspension was thawed, the cells were transferred to a 15 ml tube and 9 ml of warmed plating medium (MNP basal medium with NSF1 and glutamine) were added drop by drop in about 2 minutes. The tubes were centrifuged at 200×g for 5 minutes at room temperature. The supernatant was aspirated, the cells were resuspended in 2 ml of fresh plating medium, and 200 μl of cell suspension were counted in the NucleoCounter®. The number of cells required at 40,000 viable cells per well and the cell suspension required for plating were calculated. The calculated cell suspension to have a final concentration of 40,000 viable cells per 300 μl of plating medium was resuspended. The cell suspension was transferred to a sterile reservoir and using a multi-channel pipet 300 μl of the cell suspension were added per well of the MNP. The 96 well plates were placed in the incubator. The plates were left undisturbed for at least 24 hours. After 48 hours of plating, using a multi-channel pipettor, 200 μl of the spent medium were removed from each well and 200 μl of fresh MNP maintenance medium were added. The feeding procedure was done very gently. Extreme care was taken to avoid disturbing the adherent cells. Plates that passed QC testing were fed every other day as described until ready for downstream use.
[0075] Results
[0076] Previous results indicated that MNPs have tendency to clump after about 7-10 days during maturation process. The main reason for this clump problem was unclear. After analyzing the coating procedure of poly-D-lysine and laminin of 96-well plate for MNP plating, laminin coating step used a medium that containing B27. This step created and mixture of B27 and laminin that compete with each other to bind to poly-D-lysine surface and yield a non-homogenous surface for MNP plating. It is well-known that neurons in general are plated on the laminin and poly-D-lysine surface. Our hypothesis is B27 present in laminin coating step causes the MNP clump. A maturation MNP experiment was carried out using either poly-D-lysine coated with laminin alone or laminin+B27 mixture. The cultures were monitored at various time points during the maturation process. The results showed that after 10 days, clumping process started to appear in the culture of Laminin+B27 ( FIG. 5D ). The clumping became more apparent in MNP culturing on laminin+B27 after 17-21 days ( FIG. 5F ) while there was no clump detected in culture with laminin coating alone ( FIG. 5C and FIG. 5E ). These results were consistent with our hypothesis that the B27 is the cause for the MNP clumping during the maturation process.
Example 4
Recordkeeping
[0077] A batch record was initiated at Day 0 for every non-clinical MNP initiation and was maintained by the production department. Quality records were retained for GMP and ISO requirements as specified in internal standard operating procedures for the retention of quality records. Applicable ISO standards were followed and/or referenced.
[0078] Having now described a few embodiments of the invention, it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting, having been presented by way of example only. Numerous modifications and other embodiments are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the invention and any equivalent thereto. It can be appreciated that variations to the present invention would be readily apparent to those skilled in the art, and the present invention is intended to include those alternatives. Further, since numerous modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. Each reference cited herein is hereby incorporated in its entirety. | Methods are disclosed for the initiation and differentiation of human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) into motor neuron progenitor cells (MNPs). Methods are also disclosed for the cryopreservation of MNPs. The methods particularly relate to the simple, efficient, scalable, and reproducible generation, and subsequent frozen maintenance, of MNPs for downstream therapeutic applications. The methods can be used for the production of MNPs from various lines of hESCs and iPSCs. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to the field of door security systems. More specifically, this invention relates to an electric strike for securing a door to a door frame.
Electric strikes for securing hinged or swinging doors having projectable dead bolts or latch bolts are well-known in the field of door security systems. The electric strike can be employed alone or in combination with other conventional security systems to secure the door. The electric strike is mounted to the door frame and defines an opening in the jamb face of the door frame for reception of a bolt from a lock set such as dead bolt and/or a latch bolt. The electric strike further defines an opening in the frame face contiguous with the opening in the jamb face of the door frame.
A pivotable keeper on the electric strike selectively closes the opening in the frame face. The bolt projecting from the edge of the door engages the electric strike through the opening in the jamb face. Actuation of the electric strike unlocks the keeper to allow the door to open. The door can be therefore pushed whereby the bolt engages the strike. The keeper pivots to uncover or open the frame face opening and allow the bolt to swing therethrough and thereby allow opening of the door.
The lock assembly of a conventional electric strike is commonly operated by a solenoid. The lock assembly of an electric strike can typically be configured in either a fail safe or fail secure arrangement. In a fail safe configuration, the electric strike is automatically unlocked to allow egress through the doorway in an emergency situation, in particular, when electrical current is interrupted to the electric strike. Alternatively, in circumstances requiring increased levels of security, the lock assembly can be configured such that if electrical current is interrupted to the electric strike, the electric strike is automatically maintained in a locked arrangement.
In some prior electric strikes, the electric strike is initially permanently constructed in either a fail safe or fail secure arrangement and cannot be readily reconfigured. Therefore, two different electric strike models must be manufactured and inventoried resulting in increased costs and inefficiencies. Other prior electric strikes have required substantial modification in order to reconfigure them between a fail secure or fail safe arrangements. For example, the entire solenoid must be replaced with an opposite acting solenoid in order to reconfigure the electric strike between the fail safe and fail secure arrangement for some conventional electric strikes.
Installation costs can be significantly increased by the additional time and additional components required in order to specifically configure each electric strike for a particular security arrangement. Furthermore, if at a later time reconfiguration is required, either substantial modification to the electric strike or replacement of the entire electric strike may be required in order to change the electric strike from or to a fail safe or a fail secure configuration.
SUMMARY OF THE INVENTION
Briefly stated, the electric strike in a preferred form has a strike frame defining a jamb face opening and a frame face opening contiguous with the jamb face opening. A keeper assembly having a keeper is pivotally mounted to the strike frame. The keeper opens and closes the frame face opening to allow dead bolts and/or latch bolts to swing through the frame face opening and thereby allow selective access through a doorway.
The keeper assembly is locked in the closed position by a lock assembly which engages the keeper assembly. The lock assembly is operated by a solenoid having a displaceable plunger. The lock assembly further has a multiple pivot locking member for engaging the keeper assembly. The locking member supports a mount pivot pin pivotably engageable to a locking member mount on the strike frame. The locking member further supports a pivot pin which is pivotally engageable to the solenoid plunger. Actuation of the solenoid plunger pivotally moves the locking member to thereby lock or unlock the keeper assembly. The locking member mount and plunger solenoid together define multiple mounting positions for the locking member. The locking member can be mounted to the locking member mount and plunger solenoid in either a fail safe or fail secure arrangement. The locking member can be efficiently repositioned at any of the multiple mounting positions.
In the preferred embodiment of the electric strike, the locking member mount defines first and second mount openings and the solenoid plunger defines first and second pivot notches. Positioning the locking member so that the mount pivot pin and plunger pivot pin engage the first mount opening and first pivot notch configures the electric strike for fail secure operation. Positioning the locking member so that the mounted plunger pivot pins engage the second mount opening and the second pivot notch configures the electric strike for fail safe operation. The locking member can be readily removed and repositioned on the plunger and locking member mount to allow rapid efficient transformation of the strike between a fail safe and fail secure configurations without requiring specialized tools or additional strike components.
An object of the invention is to provide a new and improved electric strike for selectively controlling access through a doorway.
Another object of the invention is to provide an electric strike which is readily transformable between fail safe and fail secure configurations.
A further object of the invention is to provide an electric strike which has an efficient low cost construction and can be transformed to either a fail safe or fail secure mode without replacing the solenoid actuator.
A yet further object of the invention is to provide an electric strike which is resistant to jamming resulting from side loading of the strike regardless of whether the strike is configured for a fail safe or fail secure function.
These and other objects of the invention will become apparent from a review of the specification and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a rear perspective view of the electric strike of the invention without housing covers;
FIG. 2 is a top plan view of the electric strike of FIG. 1;
FIG. 3 is an exploded rear perspective view of the electric strike of FIG. 1 including housing covers and a solenoid housing;
FIG. 4 is a side elevational view of the electric strike of FIG. 1 in a fail safe configuration with the solenoid de-energized;
FIG. 5 is the electric strike view of FIG. 4 with the solenoid energized;
FIG. 6 is a side elevational view of the electric strike of FIG. 1 including the solenoid housing and wherein the electric strike is in the fail secure configuration with the solenoid de-energized;
FIG. 7 is the electric strike view of FIG. 6 wherein the solenoid is energized;
FIG. 8 is an enlarged fragmentary top view of a first alternative embodiment of the lock assembly for an electric strike in accordance with the invention wherein the lock assembly is in the fail safe configuration with the solenoid de-energized;
FIG. 9 is the lock assembly view of FIG. 8 in the fail safe configuration with the solenoid energized;
FIG. 10 is the lock assembly view of FIG. 8 in the fail secure configuration with the solenoid de-energized;
FIG. 11 is the lock assembly view of FIG. 10 in the fail secure configuration with the solenoid energized;
FIG. 12 is a partial enlarged view of a second alternative embodiment of the lock assembly in the fail secure configuration with the solenoid de-energized;
FIG. 13 is the lock assembly view of FIG. 12 with the solenoid energized;
FIG. 14 is the lock assembly view of FIG. 12 in the fail safe configuration with the solenoid de-energized;
FIG. 15 is the lock assembly view of FIG. 14 with the solenoid energized;
FIG. 16 is a front view of the electric strike of FIG. 1 in combination with a door having a lock set and a supporting door frame illustrated in phantom;
FIG. 17 is a fragmentary top view, partially in phantom, of the electric strike, door and frame of FIG. 16;
FIG. 18 is an enlarged fragmentary cut away top view of the electric strike of FIG. 5; and
FIG. 19 is an enlarged fragmentary cut away top view of the electric strike of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 16-17, an electric strike in accordance with the invention is designated generally by the numeral 10. The electric strike 10 selectively secures a door 14 to a door frame 12 to provide controlled access through the doorway. The electric strike 10 selectively functions in a dual mode capacity to provide either a fail safe or fail secure locking feature.
The electric strike 10 is mounted to the vertical edge of the door frame 12. The electric strike 10 can preferably without modification be readily mounted to either vertical side of the door frame 12 for either right or left opening doors. The door 14 has conventional hardware including a latch set 16 having a latch bolt 18 and a dead bolt 20 extending therefrom for engagement with the electric strike 10. The electric strike 10 is positioned in a cut out through the frame face 15 and jamb face 13 on the corner of the door frame 12.
With additional reference to FIGS. 1-3, the electric strike 10 has a strike frame 22. The strike frame 22 defines a jamb face opening 23 oriented toward the door 14 and generally coplanar with the jamb face 13 of the door frame 12. The strike frame 22 further defines a frame face opening 25 generally orthogonal to the jamb face opening 23 and coplanar with the frame face 15 of the door frame 12. The jamb face opening 23 and frame face opening 25 are contiguous to form a lock cavity whereby the bolts 18, 20 can swing therethrough to allow opening of the door 14. The strike frame 22 has a laterally and longitudinally extending frame face flange 24 for extension along the frame face of the door frame 12. The strike frame 22 further has a pair of opposed longitudinally extending coplanar mounting tabs 26 for receiving fasteners (not shown) to mount the electric strike 10 to the jamb face 13 of the door frame 12.
A keeper assembly 28 is mounted to the strike frame 22. The keeper assembly has a keeper 30 pivotally mounted to the strike frame 22 by a longitudinally oriented keeper pin 32. The strike frame 22 defines a keeper pin opening 33 for receiving the keeper pin 32. The keeper assembly 28 selectively closes across the frame face opening 25. The keeper 30 in the closed position and strike frame 22 together define a bolt receiving cavity 34 for receiving the bolts 18, 20 of the latch set 16. The keeper 30 is pivotable between the closed position across the frame face opening 25 and an opened position whereby the bolts 18, 20 can swing through the frame face opening 25. The keeper 30 is biased to the closed position by a torsion keeper spring 36 surrounding the keeper pin 36. The keeper spring 36 has a first end engaged with the keeper 30 and an opposite second end engaged with the strike frame 22.
A longitudinally oriented keeper face member 38 is mounted by screws 40 to the keeper 30. The keeper face member 38 defines a beveled face 42 for engaging the beveled latch bolt 18. The bevel of the latch bolt 18 engages the beveled face 42 as the door 14 closes to thereby drive the latch bolt 18 inward and allow full closure of the door 14 when the keeper 30 is in the closed position.
The keeper assembly 28 has a retaining arm 44. The retaining arm 44 is pivotally mounted to the strike frame 22 and is in camming engagement with the keeper 30. A retaining arm pin 46 threadably engages the strike frame 22 to support the retaining arm 44 onto the strike frame 22. The retaining arm 44 has an axis of rotation generally orthogonal to the axis of rotation of the keeper 30 and is positioned longitudinally in the strike frame 22 generally parallel to the keeper 30.
A compression retaining arm spring 48 engages a spring opening 50 in the retaining arm 44 and biases the retaining arm 44 against the keeper 30. The retaining arm spring 48 is maintained in compression between the retaining arm 44 and a lower housing cover 52. The lower housing cover 52 forms a rear plate against which the retaining arm spring 48 engages. The lower housing cover 52 further has transversely extending panels that cover the ends of the keeper pin opening 33 into which the keeper pin 32 is inserted, thereby maintaining the keeper pin 32 in position. The distal end portion of the retaining arm 44 supports an orthogonally oriented locking pin 54. The locking pin 54 defines an arm engagement surface 56 for engagement by a lock assembly 58.
In operation, the keeper 30 is biased to the closed position by the keeper spring 36. The retaining arm 44 is maintained in a first position against the keeper 30 by the retaining arm spring 48. A door user pushes on the door 14 such that the bolts 18, 20 engage the keeper 30 and drive the keeper 30 to the opened position. The camming engagement of the keeper 30 and the retaining arm 44 results in pivoting the retaining arm 44 outward against the biasing force of the retaining arm spring 48 when the keeper moves from the closed to the opened position. The retaining arm 44 is thereby in a second position when the keeper 30 is in the opened position. The keeper 30 is returned to the closed position by the biasing force of the keeper spring 36 once the bolts 18, 20 have cleared the keeper 30. The retaining arm 44 is then returned from the second position to the first position under the biasing force of the retaining arm spring 48.
The lock assembly 58 engages the locking pin 54 on the retaining arm 44 to lock the retaining arm 44 in the first position. Locking the retaining arm 44 in the first position locks the keeper 30 in the closed position due to the camming engagement of the retaining arm 44 and the keeper 30. The lock assembly 58 is controlled by an electrically powered solenoid 60. The solenoid 60 is mounted longitudinally in the electric strike 10 by a support cradle 62 defined in the strike frame 22. The solenoid 60 includes a solenoid housing 66 containing a solenoid coil 68. The solenoid 60 has a longitudinally movable solenoid plunger 64 mounted within the solenoid coil 68. The solenoid coil 68 is maintained in a position by first and second solenoid end portions 70, 72. The solenoid is controlled and energized over conducting cables 77. The second end portion 72 is captured in the cradle 62 of the strike frame 22.
The plunger 64 is longitudinally movable within the coil 68 between an extended position and a retracted position. The extended position of the plunger 64 is defined by a stop 82 on the strike frame 22. The retracted position of the plunger is defined by a solenoid washer 78 engaged to a shoulder on the plunger 64 and contacting the solenoid second end portion 72. A solenoid spring 80 is positioned between the solenoid washer 78 and the support cradle 62 to bias the plunger 64 to the projected position against the stop 82.
The selective dual function capability is provided by a pivoting locking member 84 which provides a dual position coupling as described below. The locking member 84 pivotally engages the plunger 64 by means of a plunger pivot pin 100 of the locking member 84. The locking member 84 has a generally U-shaped configuration with a pivoting arm 86 and a spaced parallel engagement arm 88 interconnected by a base portion 90. The pivoting arm 86 defines a through bore 87 for receiving a mount pivot pin 92 which extends into a locking member mount 94 defined by the strike frame 22.
In the preferred form, the locking member mount 94 defines longitudinally spaced first and second mount openings 96 and 98 for receiving the mount pivot pin 92. The mount pivot pin 92 is pivotably engageable with either the first or second mount openings 96, 98. The plunger pivot pin 100 extends from the base portion 90 of the locking member 84 and is oriented generally parallel to the mount pivot pin 92. The plunger 64 preferably defines a pair of longitudinally spaced first and second pivot notches 102, 104 for receiving the plunger pivot pin 100. With reference to FIGS. 18 and 19, the end portion of the engagement arm 88 of the locking member 84 defines a lock engagement surface 106 for engagement to the arm engagement surface 56 of the locking pin 54.
The lock assembly 58 operates to lock the keeper assembly 28 in the closed position. More particularly, the solenoid 60 pivots the locking member 84 via the plunger pivot pin 100 on the mount pivot pin 92 whereby the lock engagement surface 106 is positioned to be engaged to the arm engagement surface 56 of the lock pin 54 when the retaining arm 44 is in the first position. The engagement of the lock assembly 58 with the lock pin 54 prevents the retaining arm 44 from pivoting to the second position. The camming relationship between the retaining arm 44 and keeper 30 is configured such that when the retaining arm 44 is maintained in the first position, the keeper 30 cannot be rotated from the closed to the opened position, and the keeper assembly 28 is accordingly locked.
The locking member 84 is maintained in transverse position by an upper housing cover 108 mounted to the strike frame 22. The locking member 84 further preferably defines a spherical indent 110 to support a ball bearing 112 opposite the engagement surface 106. The ball bearing 112 rollingly engages the inside surface of the upper housing cover 108 to allow smooth pivoting motion of the locking member 84. The mount pivot pin 92 has a reduced end portion 93 engageable in a pair of first and second indicator openings 114, 115 defined by the upper housing cover 108. The first and second indicator openings 114, 115 are aligned with the first and second mount openings 96, 98, respectively, whereby the end portion 93 of the mount pivot pin 92 provides a visual indication through the cover 108 of the position of the mount pivot pin 92. The configuration of the locking member 84 in either the fail safe or the fail secure configuration can therefore be determined without removal of the upper housing cover 108.
With reference to FIGS. 6, 7 and 19 illustrating the fail secure configuration, the mount pivot pin 92 is positioned in the first mount opening 96 and the plunger pivot pin 100 is positioned in the first pivot notch 102 of the plunger 64. In this arrangement with the solenoid 60 de-energized, the engagement arm 88 is positioned whereby the lock engagement surface 106 is engaged to the arm engagement surface 56 of the locking pin 54. Therefore, the retaining arm 44 cannot be pivoted (see FIG. 6) and the keeper assembly 28 is in a locked state without any application of electrical energy to the solenoid 60. The keeper assembly 28 is unlocked by energizing the solenoid 60. The energization of the solenoid 60 retracts the plunger 64 overcoming the biasing force of the solenoid spring 80. The longitudinal motion of the plunger 64 from the extended to the retracted position pivots the locking member 84 on the mount pivot pin 92. The pivoting of the locking member 84 swings the engagement arm 88 of the locking member 84 to a position wherein the lock engagement surface 106 is disengaged from the arm engagement surface 56 of the retaining arm 44. The retaining arm 44 can, as a result of the disengagement of the surfaces 56, 106, be pivoted to the second position by the keeper 30. Therefore, application of an opening force to the door 14 results in the bolts 18, 20 engaging the keeper 30 and pivoting the keeper 30 to the opened position.
With reference to FIGS. 4, 5 and 18 which illustrate a fail safe configuration of the electric strike 10, the mount pivot pin 92 is positioned in the second mount opening 98 of the lock member mount 94. The plunger pivot pin 100 is further positioned in the second pivot notch 104 of the plunger 64. In the fail safe configuration, when the solenoid 60 is de-energized, the locking member 84 is maintained in a position wherein the lock engagement surface 106 of the engagement arm 88 is not engaged to the arm engagement surface 56 of the locking pin 54. Therefore, the keeper assembly 28 is unlocked when no electrical energy is applied to the solenoid 60 (see FIG. 4).
The electric strike 10 is maintained in a locked position by continual application of electrical energy to the solenoid 60 when the electric strike 10 is configured for fail safe operation. The solenoid 60 is continually energized to retract the plunger 64 and thereby overcome the biasing force of the solenoid spring 80. (See FIG. 5.) The locking member 84 is thereby pivoted to the locked position. In the locked position the lock engagement surface 106 of the engagement arm 88 is engaged to the arm engagement surface 56 of the locking pin 54 to lock the keeper assembly 28. (See FIG. 18.)
With reference to FIGS. 18 and 19, the arm engagement surface 56 and lock engagement surface are preferably contoured for efficient strike actuation under varying operational conditions. In particular, excessive friction between the engagement surfaces 56 can arise when a load is applied to the keeper and the strike is locked. Under this condition, excessive friction results in actuation of the lock failing to release the keeper until after load is moved. The engagement surfaces 56, 106 are therefore beveled for reduced friction under a loaded condition. Preferably, each engagement surface 56, 106 is bi-beveled in profile for engagement of beveled to beveled surface in both the fail safe and fail secure arrangements. The arm engagement surface 56 is double beveled and the lock engagement surface 106 is conical for engagement therewith.
The lock assembly 58 is readily reconfigurable between the fail safe configuration and the fail secure configuration. The upper housing cover 108 is removed from the strike frame 22 to begin the reconfiguration. The locking member 84, with the mount pivot pin 92 and plunger pivot pin 100, is transversely pulled out, and moved longitudinally and reinserted to reconfigure the electric strike 10. The mount pivot pin 92 and plunger pivot pin 100 thereby move between the first mounting opening 96 and first pivot notch 102, and the second mounting opening 98 and the second pivot notch 104. No additional components or specialized tools are preferably required in order to reconfigure the lock between being the fail safe configuration and fail secure configuration. The upper housing cover 108 is re-affixed to the strike frame 22 to complete the reconfiguration.
While the preferred embodiment of corresponding first and second mounting openings 96, 98 and first and second pivot notches 102, 104 is disclosed, it is readily recognizable that a reconfigurable lock assembly 58' can be accomplished by first and second mounting openings 96, 98 and a single pivot notch 102'. (See FIGS. 8-11.) With reference to FIG. 8, the mount pivot pin 92 is positioned in the first mount opening 96 and the plunger pivot pin is positioned in the pivot notch 102' in the fail safe arrangement. In the fail safe configuration, the lock engagement surface 106 of the locking member 84 is not engaged to the arm engagement surface of the locking pin 54. Therefore, the keeper assembly 28 is unlocked. The energization of the solenoid 60 results in retraction of the plunger 64' and positioning of the locking member 84 to lock the keeper assembly 28 by engagement of the locking member 84 and locking pin 54. (See FIG. 9.)
In the fail secure configuration, the mount pivot pin 92 is positioned in the second mount opening 98 and the plunger pin is again positioned in the pivot notch 102' of the plunger 64'. (See FIG. 10.) The locking member 84 is engaged to the locking pin 54 when the solenoid 60 is de-energized thereby locking the keeper assembly 28. Energization of the solenoid 60 pivots the locking member 84 whereby the locking member 84 and locking pin 54 are disengaged thereby unlocking the keeper assembly 28. (See FIG. 11.)
In an alternate further embodiment of the invention, the locking assembly 58" comprises the plunger 64 having the first and second pivot notches 102, 104 and a single mount opening 96' on a locking member mount 94'. (See FIGS. 12-15.) In the fail secure configuration, the locking member 84 is pivotally mounted to the locking member mount 94' by the mount pivot pin 92 engaging the single mount opening 96'. (See FIG. 12.) The plunger pivot pin 100 is engaged to the first pivot notch 102 whereby the locking member 84 locks the keeper assembly 28 in the closed position. The energization of the solenoid 60 pivots the locking member 84 whereby the keeper assembly 28 is unlocked and can be opened. (See FIG. 13.)
In the fail safe configuration, the plunger pivot pin 100 is positioned to engage the second pivot notch 104 whereby the keeper assembly 28 is maintained in an unlocked condition. (See FIG. 14.) The energization of the solenoid 60 retracts the plunger 64 thereby pivoting the locking member 84 such that the keeper assembly 28 is locked in the closed position by engagement of the locking member 84 and the locking pin 54. (See FIG. 15.)
While a preferred embodiment of the present invention has been illustrated and described in detail, it should be readily appreciated that many modifications and changes thereto are within the ability of those of ordinary skill in the art. Therefore, the appended claims are intended to cover any and all of such modifications which fall within the true spirit and scope of the invention. | An electrically controlled strike has a strike frame defining a jamb face opening and a strike face opening. A keeper assembly selectively closes across the frame face opening. A lock assembly readily reconfigurable between fail secure and fail safe arrangements locks the keeper in the closed position. The actuator of the lock assembly drives a plunger between first and second positions to lock and unlock the keeper assembly. The plunger is biased to the first position. A lock member is mountable to the plunger in the fail safe configuration wherein the keeper is released when the plunger is in the second position. The locking member is also engageable to the plunger in a fail secure arrangement wherein the keeper is locked when the plunger is in the first position and the keeper is released when the plunger is in the second position. The strike also incorporates a jamming resistant feature for both the fail safe and fail secure configurations. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
The present application claims priority on U.S. Provisional Application for Patent Ser. No. 60/406,389 filed Aug. 27, 2002, the entire disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to methods for operating a register at a retail stores and to methods for enhancing revenue at retail stores. The invention also relates to devices, systems, and software for implementing the methodology of the invention.
Coupons are conventionally distributed in print media, over the Internet, or at a retail store (either on display or printed on the back of receipts). Conventional coupons are for fixed amounts and are distributed regardless of an individual sale. In addition, a number of retail stores may offer discounts based on the total sales price of a transaction. For example, a store may state, “Receive $5 off on purchases of $40 or more.” This conventional coupon system has been in place for years and has remained relatively static.
In view of the foregoing, there remains a need in the retail industry for a coupon system that motivates consumers to increase the amount of an individual transaction and, therefore, to increase revenues of participating retailers.
SUMMARY OF THE INVENTION
The present invention provides systems and methods for distributing coupons by a retailer. The coupons distributed in the invention are “third-party” coupons, that is, coupons for goods or services that are unrelated to those of the retailer and offered by a third-party retailer. For example, if a supermarket is distributing the coupons, then the coupons may be for tools at a home-improvement store or for tax services by an accountant.
The distribution methods of the invention increase the revenue of a retailer. More specifically, a consumer is presented a coupon when the value of the transaction exceeds a threshold. In a number of embodiments, the threshold is the average sale per transaction of the retailer. Accordingly, consumers will be motivated to increase spending so that coupons can be earned. The revenue of a retailer may be further enhanced by selling advertising space within the retailer's establishment to participating third-party retailers.
The methods and apparatus of the invention are equally applicable to both “brick and mortar” and “click and mortar” retailing. In the latter, consumers may shop on the Internet and print out coupons during checkout if the threshold for a particular website is met.
Other features and advantages of the present invention will become apparent to those skilled in the art from a consideration of the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic view of a check-out counter;
FIG. 2 is a block diagram of a system for printing coupons;
FIG. 3 is a flow chart illustrating revenue-generating methodology;
FIG. 4 is a schematic diagram illustrating a relationship between a Retail Store and Participating Retailers;
FIG. 5 is a schematic view of advertising space placards;
FIG. 6 is a schematic view of a placard;
FIG. 7 is a flow chart illustrating methodology of the invention;
FIG. 8 is a schematic view of coupons;
FIG. 9 is a flow chart illustrating alternative methodology of the invention;
FIG. 10 is a schematic view of a Internet-based coupon issuing system;
FIG. 11 is a schematic view of a graphical user interface for use in an Internet-based coupon system;
FIG. 12 is a flow chart illustrating server methodology of issuing coupons;
FIG. 13 is a flow chart illustrating consumer methodology for receiving coupons; and
FIG. 14 is a schematic view of a pop-up window for enabling the selection of coupons.
DETAILED DESCRIPTION OF THE INVENTION
The present invention presents apparatus, systems, devices, methods, and processes for generating and increasing revenue at a retail store. According to a number of embodiments of the invention as exemplified in FIG. 1 , a check-out stand 100 of a retail store may include a register 102 with a till 104 and a printer 106 for printing receipts. In addition, a number of embodiments may also include a display 108 and a keypad 110 .
The check-out stand 100 may also include a scanner 112 for scanning UPC codes and a point-of-sale (POS) device 114 for scanning debit and credit cards. In addition, in a number of embodiments, such as grocery stores, the check-out stand 100 may also include counter space 116 and a conveyor belt 118 . The check-out stand 100 may further include a secondary monitor 119 visible to consumers passing through the check-out stand. The secondary monitor 119 may be a touch screen-type monitor so that a consumer may select a coupon as described in more detail below.
Referencing FIG. 2 , in a number of embodiments the register 102 may include a computer with a processor 120 and memory 122 . The processor 120 may be in communication with the keypad 110 , the scanner 112 , and the printer 106 .
Referencing FIGS. 3 and 4 , a Retail Store A may generate revenue by selling, leasing, or renting advertising space to Participating Retailers M, N, and O (step S 100 ). The advertising space may be in the form of placards 124 located at, for example, the counter space 116 or the conveyor belt 118 at the check-out stand 100 . Alternatively, the placards 124 may be located throughout the store, for example, on the doors 126 , entry mats 127 , or shopping carts 128 as shown in FIG. 5 . In other embodiments, the advertising space may be in the form ads 129 shown on the consumer display 119 at the check-out stand 100 .
In a number of embodiments a shown in FIG. 6 , a placard 124 or an ad 129 may include a logo of a Participating Retailer and text to the effect, “Purchase more than $(threshold T) at Retail Store A and receive a coupon for (percentage P)% off your next purchase at Participating Retailer M.” According to a number of embodiments, the threshold T may be the average sale per customer of Retail Store A.
According to some of the embodiments, Retail Store A may sell advertising space to more than one Participating Retailer, as shown by way of example of the plurality of placards 124 at the counter 116 in FIG. 1 . Each Participating Retailer may have a different threshold T and a different percentage P.
As shown in FIG. 4 , Retail Store A sells the products of Entity B, C, and D. According to a number of embodiments, the Retail Store A sells advertising space to Participating Retailers unassociated with the products of the Entities. For example, if Retail Store A is a supermarket selling milk, bread, and fruit (i.e., goods of Entities B, C, and D), then Retail Store A may sell advertising space to retailers of automotive parts, clothing, and dental services (i.e., goods and services of Participating Retailers M, N, and O).
Once advertising space is sold to a Participating Retailer, then the Retail Store A may increase the average sale of Retail Store A by printing coupons for one or more Participating Retailers when an individual total sale exceeds a minimum purchase requirement or threshold T, for example, the average sale (step S 102 ). Shoppers at Retail Store A may be motivated to purchase more goods and/or services of Retail Store A so that their individual total sale exceeds the threshold T in order to receive discounts at the Participating Retailers. Accordingly, the average sale of Retail Store A will be increased.
According to a number of embodiments as illustrated in FIG. 7 , during an individual sale of a shopper at a check-out stand 100 of Retail Store A, the processor 120 adds the price of each item purchased by the shopper to reach a total sale S(t) (step S 110 ). The prices may be input through the scanner 112 or the keypad 110 . The processor 120 may then compare the individual total sale S(t) to a threshold T, for example, the average individual sale S(avg) of the Retail Store (step S 112 ). If the total sale S(t) is greater than the average sale S(avg) (step S 114 ), then the processor 120 may cause the printer 106 to print a coupon for one or more of the Participating Retailers (step S 116 ). If the total sale S(t) is not greater than the average sale S(avg), then the processor 120 may cause the printer 106 to print a receipt for the individual sale (step S 118 ). The average sale S(avg) may be stored in the memory 122 .
In some of the embodiments, if the total sale S(t) is not greater than the average sale S(avg), the processor 120 may cause the printer 106 to print a message on the receipt indicating that if the shopper had spent $(difference D) more, then a coupon would have been printed, where the difference D is between the average sale S(avg) and the total sale S(t) for the individual.
According to a number of embodiments, the processor 120 may be configured to maintain a current average sale S(avg). That is, the processor 120 may recalculate the average sale S(avg) after each purchase with the current individual total sale S(t) (step S 120 ). In retail stores with a plurality of check-out stands 100 , a centralized computer may be used to maintain the current average sale of all of the check-out stands. The process continues for the next individual sale (step S 122 ). The current average sale S(avg) may be displayed in the store, such as on the secondary monitor 119 (see FIG. 1 ) or on a central display in the store (not shown).
An example of a coupon 130 that may be printed when the total individual sale S(t) exceeds a threshold T is illustrated in FIG. 8 . The coupon 130 may include the name of the Participating Retailer, the percentage of the discount, an expiration date, a coupon number, a barcode, etc. As mentioned, coupons 130 for each of the Participating Retailers may be printed when the threshold T is exceeded.
According to some of the embodiments, the printed coupons 130 may be individually printed and presented to the shopper at Retail Store A or may be printed on the receipt (either the front or the back of the receipt) at step S 118 . In addition, if more than one coupon 130 is printed, there may be perforations between the coupons to facilitate separation by a user.
More than one printer may be used to perform the printing of the coupons 130 . For example, in a number of embodiments, the check-out stand 100 may include a dedicated printer 132 for printing the coupons 130 , while the other printer 106 prints the receipt.
According to some of the embodiments, the display 108 at the check-out stand 100 may display a running total T(r) of the individual sale so that a shopper is informed of whether or not the threshold T is likely to be met by the individual sale. If, for example, the running total T(r) is short of the threshold T by a small amount, then the shopper will be motivated to make an impulse purchase of goods located at the check-out stand 100 to push the running total T(r) [and, therefore, the total sale S(t)] over the threshold T.
According to other embodiments of the invention as illustrated in FIG. 9 , the processor 120 may be configured to increase the percentage P as a function of the total sale S(t). For example, if the threshold T is exceeded by the total sale S(t), then a coupon 130 for one or more Participating Retailers may be printed. The percentage P of the discount of the coupon 130 may be a function of the amount of the total sale S(t) over the threshold T.
More specifically, if the total sale S(t) is greater than or equal to the threshold T but less than a first limit T( 1 ), then the processor 120 may cause the printer 106 to print a first percentage P( 1 ) (e.g., 10%) on the coupon 130 (step S 124 ). If the total sale S(t) is greater than or equal the first limit T( 1 ) but less than a second limit T( 2 ), then the processor 120 may cause the printer 106 to print a second percentage P( 2 ) (e.g., 15%) on the coupon 130 (step S 126 ). If the total sale S(t) is greater than or equal the second limit T( 2 ) but less than a third limit T( 3 ), then the processor 120 may cause the printer 106 to print a third percentage P( 3 ) (e.g., 20%) on the coupon 130 (step S 128 ).
The limits T may be fixed or may be recalculated for each individual sale based on the current average sale S(avg). In addition, the limits T may be a fixed amount greater than the threshold T or may be percentage of the current average sale S(avg), e.g., 110% of S(avg), 120% of S(avg), etc.
In other embodiments, the system 100 may enable a user to select the coupon. More specifically, if the threshold T is exceeded, a plurality of coupons may be displayed on the second monitor 119 (see FIG. 1 ). The user may then selected which of the coupons is to be printed. The selection may be verbally or through the use of a touch screen, for example.
In addition to the “brick and mortar” retail example provided above, the principles of the present invention are analogously applicable to Internet commerce as well. More specifically, as shown in FIG. 10 , a network 140 including a consumer computer 142 with a monitor 143 connected to a seller server 144 via the world-wide web 146 enables consumers to receive coupons on their own printer 148 according to the invention.
Referencing FIG. 11 , an example of a graphical user interface (GUI) 150 for display on the monitor 143 of the consumer computer 142 in accordance with the principles of the invention is illustrated. The GUI 150 may include a shopping cart 152 such as item information and unit price. Additionally, the GUI 150 may include a threshold field 154 , a subtotal field 156 , and a difference field 158 .
With additional reference to FIGS. 12 and 13 , the server 144 maintains the threshold T for a particular website and displays the threshold T (S 130 ) in the threshold field 154 of the GUI 150 . When shopping (S 132 ), a consumer then adds items from the website to the shopping cart (S 134 ). The server. 144 may then maintain a running subtotal S(sub) and display the subtotal S(sub) (S 136 ) in the subtotal filed 156 . In addition, the difference between the threshold T and the subtotal S(sub) may be calculated and displayed (S 138 ) in the difference field 158 .
The consumer may then view the subtotal S(sub) (S 140 ) and the difference to determine whether or not the threshold T has been reached. In accordance with this embodiment, a signal that the threshold T has been reached may be in the form of a positive difference, i.e., subtotal S(sub) less threshold T. If the threshold T has not been reached, the consumer may continue shopping (S 144 ) to increase the value of the transaction until the threshold T is met, if desired.
If the subtotal S(sub) is greater than the threshold T (i.e., if the difference is positive), then the server 144 may enable a select coupon icon 160 (S 146 ) in the GUI 150 . This may also act as a signal (see step S 142 ). If the select coupon icon 160 is selected (S 148 ), then a pop-up window 162 may be displayed with a plurality of coupon choices 164 , one of which the consumer may select, as shown in FIG. 14 .
If the consumer does not want to continue shopping, then a checkout icon 166 may be selected (S 150 ), thereby initiating a checkout sequence (S 152 ). Upon checking out, if the threshold T was met, then the consumer may print out the selected coupon (S 154 ), with the coupon being printed (SI 56 ) at the printer 148 .
In the foregoing description, coupon is used to describe a coupon issued by Retailer A for the goods or the services of Retailer B, wherein the goods/services of Retailer B are unrelated to those of Retailer A. Accordingly, for the purposes of this description, these coupons are referred to as third-party coupons.
Those skilled in the art will understand that the preceding exemplary embodiments of the present invention provide the foundation for numerous alternatives and modifications thereto. These and other modifications are also within the scope of the present invention. Accordingly, the present invention is not limited to that precisely as shown and described above but by the scope of the appended claims. | The present invention provides systems and methods for distributing coupons by a retailer. The coupons distributed in the invention are “third-party” coupons, that is, coupons for goods or services that are unrelated to those of the retailer and offered by a third-party retailer. For example, if the coupons are being distributed by a supermarket, then the coupons may be for tools at a home-improvement store or for tax services by an accountant. The distribution methods of the invention increases the revenue of a retailer. More specifically, a consumer is presented a coupon when the value of the transaction exceeds a threshold. In a number of embodiments, the threshold is the average sale per transaction of the retailer. Accordingly, consumers will be motivated to increase spending so that coupons can be earned. The methods and apparatus of the invention are equally applicable to both “brick and mortar” and “click and mortar” retailing. In the latter, consumers may shop on the Internet and print out coupons during checkout if the threshold for a particular website is met. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to microwave antennas.
More particularly the invention relates to microwave antennas having both a wide elevation beamwidth and a wide azimuth beamwidth over a wide frequency bandwidth. Such antennas find application, for example, in airborne ground surveillance radar systems where the antenna is mounted on the nose of the aircraft and directed ahead of the aircraft.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel form of microwave antenna capable of meeting these requirements.
According to the present invention a microwave antenna comprises a horn radiator having a tubular radiating end portion, there being at least four open-ended cut-outs in said end portion.
Preferably said cut-outs are substantially identical, substantially uniformly distributed around said end portion, and are of even number.
In one particular embodiment said cut-outs comprise parallel-side slots. Preferably the slots open into semi-circular portions of the cut-outs at their open ends. In one such arrangement the slots extend parallel to the axis of the tubular end portion and there is provided between each pair of adjacent slots a capacitive stud which extends radially inwards of the tubular end portion. In another such embodiment the slots extend at an acute angle to the axis of the tubular end portion, typically at 45°. There may be a dielectric lens which fits over the end portion.
Where the cut-outs are in the form of parallel-sided slots there are suitably ten cut-outs.
In another embodiment of the invention said cut-outs are V-shaped with their wider ends in the plane of the radiating end of the horn. Preferably the cut-outs have included angles of substantially 90° and adjacent cut-outs meet one another at their wider ends.
The horn radiator preferably houses a dielectric impedance-matching insert.
BRIEF DESCRIPTION OF THE DRAWINGS
Several microwave antennas in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a sectional view of a first antenna;
FIG. 2 is a perspective view of the antenna of FIG. 1;
FIG. 3 is a perspective view of a second antenna;
FIG. 4 shows the antenna of FIG. 3 fitted with a dielectric lens; and
FIG. 5 is a perspective view of a third antenna.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, the first antenna to be described comprises a horn radiator defined by a hollow electrically-conductive member 1 of circular cross-section, suitable of aluminum. A mounting flange 3 at one end of the horn member 1 enables the antenna to be secured to a polarizer (not shown). The horn member 1 has a plain cylindrical outer surface, but internally it has a conical, i.e. tapered, transition from a large bore outer portion, which provides a tubular radiating end portion, to a small bore inner portion. The tapered portion of member 1 constitutes the `horn`.
The horn member 1 houses an impedance-matching insert 5 of dielectric material, suitably PTFE. This insert 5 has a `solid` cylindrical part which is a close fit within the tubular end portion of the member 1 and extends from the tapered portion (approximately) half way to the open end of the radiator. This cylindrical part of the insert 5 may be integral with a `conical` section which fits snugly within the tapered portion. The `conical` section is `relieved` so as to provide cruciform cross-section.
In an alternative construction, the member 1 is tubular, e.g. it has a uniform internal diameter, and the tapered portion is provided by the insertion into the member 1 of a plurality of electrically-conductive wedges (not shown). Preferably there are four such wedges symmetrically, i.e. equi-angularly, distributed within the member 1 towards the end adjacent the mounting flange 3.
Extending into the horn member 1 from its open end there are ten cut-outs 7, each in the form of a parallel-sided slot 7A extending parallel to the axis of the member 1. Each slot 7A opens into a semi-circular cut-out portion 7B at its open end.
The cut-outs 7 are all of the same shape and size and are uniformly distributed around the circumference of the horn member 1. The cut-outs 7 have a length not less than a quarter of the free space wavelength of signals at the upper end of the frequency band width over which the antenna is required to operate.
Between each pair of adjacent slots 7A there is a capacitive stud 9 in the form of a projection extending radially inwards form the tubular end portion of the member 1. The studs 9 may be of fixed length but preferably are of screw form for ease of adjustment. In FIG. 2 tapped holes 9A only for the studs 9 are shown for clarity.
The cut-outs 7 serve to allow sideways scatter of energy and thereby increase the effective beamwidth of the antenna in respect of those components of circularly polarized waves in the member 1 whose E-fields are directed across the width of the slot portions 7A of the cut-outs 7.
The capacitive studs 9 serve to increase the effective beamwidth of the antenna in respect of those components whose E-fields are in the direction of the lengths of the slot portions 7A of the cut-outs 7.
The semi-circular portions 7B of the cut-outs 7 serve to reduce edge effects and the inner ends of the slot portions 7A of the cut-outs are radiused for the same purpose. The semi-circular portions 7B also serve to increase beamwidth, more especially at the upper end of the operating frequency band.
In one particular embodiment of the antenna of FIGS. 1 and 2 for use with signals in the frequency band 8 to 18 GHz the end portion of the horn member 1 in which the cut-outs 7 are formed has an external diameter of 23.8 mm and an internal diameter of 19.9 mm, the cut-outs 7 have an axial length of 8 mm, the slot portions 7A have a width of 2 mm and the semi-circular portions a radius of 2.5 mm. The tapered portion of the horn member 1 starts at a distance of 15 mm from the open end of the member 1 and the tapered section is itself 15 mm long.
With these dimensions the antenna has an azimuth and elevation 3 dB beam width of 80±7.5 degrees over the whole 8-18 GHz bandwidth.
Referring to FIG. 3, the second antenna to be described by way of example comprises a horn member 11, flange 13 and impedance insert 15 housed in the member 11, which correspond to the members 1, 3 and 5 respectively of the antenna of FIGS. 1 and 2, but has ten cut-outs 17 of different form. In this antenna the cut-outs 17, whilst including semi-circular portions 17B identical to those of the antenna of FIGS. 1 and 2, have parallel-sided slot-portions 17A which extend at an acute angle of 45° to the axis of the horn member 11. In addition, no capacitive studs corresponding to the studs 9 of the antenna of FIGS. 1 and 2 are provided in the antenna of FIG. 3, the acute angling of the slot-portions 17A rendering them unnecessary.
For nominally the same performance as the antenna of FIGS. 1 and 2, the axial length of the cut-outs 17 of the antenna of FIG. 3 will be the same as the axial length of the cut-outs 7 of the antenna of FIGS. 1 and 2.
To further increase beamwidth the antenna of FIG. 3 may be provided with a dielectric lens in the form of a bung 19, made for example of PTFE, fitting over the open end of the member 1, as illustrated in FIG. 4. For an antenna of dimensions as given above, the bung 19 suitably has a radial dimension of 3 mm over an axial length of 8 mm, where it fits around the horn member 11, and reduces in internal diameter to 18 mm over an axial length of 5 mm, where it projects beyond the tubular end portion of the horn member 11. The outer end of the bung 19 is suitably of semi-circular form.
With the lens 19 fitted an azimuth and elevation 3 dB beam width of 90+/-degrees is obtained over a 3:1 frequency bandwidth.
Referring to FIG. 5, the third antenna to be described by way of example again has a horn member 21, flange 23 and impedance insert 25, but in this case only four cut-outs 27 which are V-shaped are provided. The cut-outs 27 have their wider ends in the plane of the open end of the member 21 and at their wider ends subtend an angle of 90° at the axis of the member 21 so as to meet one another at their wider ends. No capacitive studs are provided. The V-shaped cut-outs 27 are suitably of right-angled form, i.e. have included angles of substantially 90°.
Whilst the antenna of FIG. 5 will not provide such good performance as the antennas of FIGS. 1 to 4, it nevertheless exhibits a significant improvement over an antenna wherein the member corresponding to horn member 21 of FIG. 5 i plane-ended, i.e. without any cut-outs.
It will be appreciated that whilst in the embodiment of the invention that have been described the cut-outs are identical, uniformly distributed, and of even number, none of these features is essential in an antenna according to the invention, for instance where unequal azimuth and elevation beamwidths are required. | A microwave horn antenna comprising a hollow cylindrical horn (11) having a rear section of tapered internal dimension extending towards a tubular radiation open end. The open end incorporates a number of parallel-sided slots (17), which extend at angles of 45 degrees to the horn axis. The slots (17) terminate at the open end in semi-circular cut-out portions (17B). A dielectric lens (19) is fitted over the open end of the horn. The antenna provides a wide beamwidth of approximately 90 degrees over a frequency ban of 8 to 18 GHz. | 7 |
This is a continuation of application Ser. No. 07/881,446 filed May 11, 1992, now abandoned.
BACKGROUND OF THE INVENTION
The invention deals with a billet live roller feed bed upstream of cooling beds, where worm type conveyor rollers, arranged parallel to the roller bed rollers, transfer the rolled material onto the cooling bed transversely to the conveyance direction.
Prior to transferring the billets, coming finish-rolled and subdivided into commercial lengths from a rolling mill to the cooling bed, it is necessary to brake the billets to a stop. Only then are they lifted onto the cooling bed in accordance with the cooling bed cycle, or they slide in a known manner known such as onto the first grate of the cooling bed. Since, to be sure, billets having different dimensions are rolled in a rolling mill, it is unavoidable that the billets arrive on the runout table with speeds differing considerably from each other, this from one to another dimension, because billets of smaller cross-section are rolled at a speed several times higher in comparison with the largest possible billet dimension to be rolled in the rolling mill.
The runoff speed, changing as a function of the rolling program, results in the billets having braking travels of different length, which billets must come to a stop prior to being transferred to the cooling bed. It must be borne in mind that the square of the travel speed is inserted when calculating the braking travel, assuming a constant coefficient of friction μ. For a smooth operational sequence and an occupancy of the cooling bed according to the cooling bed cycle, in spite of that, considerable control measures and a large construction resource are required in known cooling beds, as for instance in a live roller feed bed of this type the coupling of several rolls which requires appropriate clutches.
SUMMARY OF THE INVENTION
It is an object of the invention to adapt a billet live roller feed bed of the previously discussed type to changing rolling speed with the use of minor resources of machine technology, and to simplify the passing of the billets over to a cooling bed.
Pursuant to this object, and others which will become apparent hereafter, one aspect of the present invention resides in the transverse conveyor rollers having screw or spiral turns of differing pitch. Surprisingly, it can be achieved by this measure always to maintain a defined braking and discharge position independently of the rolling or billet speed, which means that a constant spacing of the billets is always assured. Due to the difference in pitch a third, namely an intermediate, position is possible between the entry position of the billet and the braking position on the runout table. A billet occupying the intermediate position is conveyed further at constant speed (runout table speed). The braking is initiated from the intermediate position, and because of the screw pitch there results preferably in the course of a 180° rotation of the transverse conveyor rollers a sideways displacement of this billet into the braking position, without that a following subsequent billet located in the entry position being affected. A subsequent billet remains without change in the entry position during displacement of the preceding billet.
It is advisable to arrange a brake chute within the braking region for braking the billet to the braked position.
If the pitch of a first screw turn, emanating from the ends of the transverse conveyor rollers facing away from the cooling bed, corresponds to at least two times the largest occurring billet dimension plus the bead thickness or width and a second screw turn, extending in a braking region configured at the ends of the transverse conveyor rollers facing the cooling bed, is provided with a zero pitch across a 180° sector of the transverse conveyor rollers, the transverse conveyor rollers displacing the billets can be coordinated in such a way, with the turnover cooling bed preferably designed as a notched bar cooling bed, that a billet arrives into the braking position after one revolution of the transverse conveyor rollers, meaning it is resting on the braking chute and comes to a complete stop there. After a further, thus second, complete revolution of the transverse conveyor rollers the billet is transferred from the braking chute to the notched bar cooling bed which is matched, as far as its graduation (rake recesses) is concerned, to the displacement sequence caused by the conveyor rollers (the billet is dumped). Simultaneously with this, a following billet is transversely conveyed from the entry position into the braking position.
The angular value of the roller revolution defining the pitch is not limited to a 180° division. It can be chosen at random, wherein however at the front, meaning at the ends of the conveyor rollers facing away from the cooling bed, it must always be greater than at the rear, meaning at the ends facing the cooling bed. The pitch of the screw turn at the roller rear ends is in addition dependent upon the tooth pitch of the notched bar cooling bed taking over the billet.
The operational sequence described above is repeated in accordance with the quantity of the entering billets, wherein the screw turn designed in the braking region without a pitch upon a 180° segment of the transverse conveyor rollers assures that the billet occupying its position in the braking position is not affected during the displacement of a following billet into the intermediate position, which entails a 180° turn of the conveyor rollers. It makes no difference with what speed the rolling mill functions, a billet remains always in the braked position of rest until a following billet has arrived in the braking position. Only then is the preceding billet transferred onto the cooling bed. The transverse conveyor rollers receive their set or desired values from an overriding control of the rolling mill. They are driven by rpm regulated DC motors, and their initial position for the respective rotations of preferably 180° is observed electromechanically by means of a monitoring system.
The transverse conveyor rollers can be provided with beads forming the helical or screw turns, which beads can be applied for instance by welding, so that existing runout tables can also be subsequently reworked without requiring new rollers. With newly fabricated rollers the screw turns can be directly cast on during the manufacturing process. Because of the pitch of the screw turns, billets move from one position into the next one with each 180° turn o*f the transverse conveyor rollers, with the intermediate positions of rest described. When dimensioning the pitch of the screw turn at the front roller end, it must be based on two times the largest billet dimension which has to be rolled, including the thickness of the beads forming the screw turn.
The ends of the transverse conveyor rollers facing the cooling bed can expediently be designed for the transfer of the billets from the first into the second notch of the rake. This enables a double occupancy of the cooling bed with billets of small dimensions and thus a rapid cyclical follow up sequence. On the other hand, only every second notch is occupied if one is dealing with large billet dimensions.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows diagrammatically a live roller feed bed next to a cooling bed in plan view; and
FIGS. 2-12 show diagrammatically a side view of a conveyor roller of a transverse conveyor directing billets onto a rake-type cooling bed, in different operating stages.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, there follows upon a rolling mill 1 a live roller feed bed 2 with dividing shears 3 integrated therein for subdividing the rolled strand into cooling bed lengths which are dependent upon the longitudinal dimensions of a downstream turning cooling bed 4 configured as a rake-type cooling bed and the permissible minimum and maximum dimensions of the partial lengths depending upon the cooling bed cycle. A transverse conveyor 5 is located upstream of the cooling bed 4 and consists of numerous transverse conveyor rollers 6, shown in FIG. 1 by a thick line, arranged to be parallel to the runout table rollers. These rollers are equipped with beads 9 (compare FIG. 2) extending helically across the roller length and forming screw or worm turns 7, 8 of differing pitch, with billets delivered by the live roller feed bed 2 to the transverse conveyor 5 being moved by the beads 9 of respective screw turns 7 and 8.
As is shown in detail in FIGS. 2-12 with an example of six billets numbered 11 to 16 running out onto the transverse conveyor 5, the billet 11, which has to be transferred in a conveyance direction 17 onto the cooling bed 4, arrives in the entry position I upon the transverse conveyor roller 6 at the ends of the transverse conveyor roller 6 facing away from the cooling bed. The distance traveled from the entry position in the transverse conveying direction 17 to the cooling bed 4 is apart from this subdivided in the sequence shown into an intermediate position II, a braking position III and a dumping or throw off position IV. In a braking region 18 of the transverse conveyor facing the cooling bed 4, a braking shoot (not shown) here is arranged, which brakes the billets 11 to 16 to a complete stop prior to the dumping or transferring onto the cooling bed 4.
The pitch of the screw turn 7 of the transverse conveyor rollers 6 corresponds to twice the largest encountered billet dimension plus the wall thickness of the bead 9 (compare, for example, FIG. 3). With a 180° turn of the transverse conveyor roller 6, the billet 11 comes out of the entry position I and arrives into the intermediate position II and thus creates space for the first following billet 12 (compare a and b in FIG. 2) running out onto the transverse conveyor roller 6. The first billet 11 occupying the intermediate position II is to begin with conveyed further at the constant speed of the roller runout table, before exiting out of this position due to a transverse conveyance caused by the screw turn 7 into the braking position III of the braking region 18, meaning upon the brake chute arranged there. As can be seen from FIG. 4 showing the conveyor roller 6 after a complete revolution, the following billet 12 remains in the entry position I and is not subjected to any transverse motion along the roller 6 during the period of the transverse conveyance of the billet 11 from the intermediate position II to the braking position III. The billet 12 remains at the entry position I because, due to the large pitch of the screw turn 7, the billet 12 is not engaged by a respective bead 9 until the preceeding billet II arrives at the braking position III. Only after the second following billet 13 has arrived in the region of the entry position I of the transverse conveyor rollers 6, is the preceding following billet 12 displaced into the adjacent, or intermediate, position II (compare FIG. 2d). Herein however the first billet 11 is not conveyed further, but rather remains in the braking position III.
The displacement of the first following billet 12 without affecting the billet 11 is achieved by providing a zero pitch on the screw turn 8 across a sector 19 diagrammatically designated by 180° in FIG. 4 with the screw turn 8 being located in the braking region. As seen from FIG. 5, the billets 11 to 13 which have run out up to now lie, after 380° rotation of the transverse conveyor roller 6, directly next to each other in the positions I to III.
Upon an additional 180° rotation as shown in FIG. 6, the billet 11 arrives in the dumping position IV because of the screw turn 7,8, designed with different pitches and the first following billet 12 arrives in the braking position III, while the second following billet 13 remains in the entry position I. The billet 11 arrives out of the dumping position IV onto the turnover cooling bed 4 provided with jagged receiving recesses or notches. There it is taken over by rakes (hoisting beams) 21 and simultaneously turned during the cyclical forward movement of the transverse conveyor arrangement 17.
As is diagrammatically outlined in FIG. 8, the ends of the transverse conveyor roller 6 facing the cooling bed 4 are designed so that the billets 11 to 16 are transported out of the first notch of the rake 21 into the second notch and only after that are cyclically conveyed further from notch to notch by the mobile rakes 21 of the cooling bed 4. In this way a double occupancy of the cooling bed 4 can be achieved when processing billets having small dimensions. In the case of large billet dimensions, only every second notch of the rakes 21 is occupied due to space reasons.
The sequence described above is repeated with each new runout follow up billet 14-16, with each 180° rotation of the transverse conveyor rollers 6, as is made clear in FIGS. 7-12, wherein FIG. 12 shows a situation after five complete roller revolutions (1800°). Irrespective however of the speed with which the billets run out onto the transverse conveyor roller 6, it is achieved during their conveying in the transverse conveyor direction 17, because of the differing pitches of the screw turn 7,8, that during the displacement of one billet into the braking position III, a following billet remains unaffected in the entry position I and the spacing between a billet in the dumping position IV and one in the braking position III can always be maintained constant.
While the invention has been illustrated and described as embodied in a billet live roller feed bed, 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.
What is claimed as new and desired to be protected by letters patent is set forth in the appended claims. | A billet live roller bed upstream of cooling beds, where conveyor rollers designed in a worm or screw shaped manner and arranged to be parallel to the roller bed rollers transfer the rolled materials transversely to the conveyance direction onto the cooling bed, can be adapted to changing rolling speeds with small resources in machining technology, if the transverse conveyor rollers have screw turns with different pitches. | 1 |
RELATED APPLICATIONS
This application is a continuation application of U.S. patent application Ser. No. 12/900,908 filed on Oct. 8, 2010, now U.S. Pat. No. 8,175,662 which itself is a continuation application of U.S. patent application Ser. No. 10/995,221 filed on Nov. 24, 2004, now U.S. Pat. No. 7,826,874.
FIELD OF DISCLOSURE
The present disclosure relates to a system and method for activating a communication device, more particularly activating the device after sensing intent to use the device.
BACKGROUND
Current wireless handheld mobile communication devices perform a variety of functions to enable mobile users to stay current with information and communications, such as e-mail, corporate data and organizer information while they are away from their desks. A wireless connection to a server allows a mobile communication device to receive updates to previously received information and communications. The handheld devices optimally are lightweight, compact and low power to facilitate usage by professionals on the go. In order to conserve battery power, the devices can be placed into reduced power or sleep modes, where portions of the device (such as the display and alarms) are either not used, powered off, or used in a restricted, power-saving mode. Such modes are generally programmable, wherein the user manually programs the device to have: (i) a start or sleep time; and (ii) an end or wake-up time. At the sleep time, the devices automatically enter a predetermined sleep mode and shut off predetermined portions of the devices. Generally in a sleep mode, sufficient power is still provided to the devices in order for it to maintain its data, essential programs and clock information and to operate programs and processes during the sleep mode. At the wake-up time, the devices are typically brought back to a full power mode, where all functionality of the devices is available to the user.
However, often prior art systems and methods for power control of such devices are inflexible in their program modes, typically mandating that if the device is required to be used during its sleep mode, the device must be manually activated in some manner (e.g. activating a power switch), and then manually de-activated in some manner (e.g. de-activating the power switch).
In some circumstances, a user of a device may need to only use the device for a brief period of time to check a status of something tracked by the device, e.g. the receipt of any incoming messages, calls or emails or even the current time. The prior art devices require the user to actively turn on the device by pressing an appropriate key, use it, then actively turn off the device. This process is cumbersome, especially if the user wishes only to check the status of an event.
There is a need for a system and method which addresses deficiencies in the prior art of selectively turning on (activating) and then turning off (deactivating) a communication device.
SUMMARY
In a first aspect, a power management system for an electronic device is provided. The system comprises: a microprocessor controlling the electronic device; an accelerometer; and a power application operating on the microprocessor. The application provides instructions to the microprocessor to place the electronic device in a low power state from a higher power state upon determining from movement data generated by the accelerometer that the electronic device has been returned to around a resting location where the electronic device was previously in a stationary state from a first location that is in a spaced relationship to the resting location.
In the system, the power application may further provide instructions to the microprocessor to calculate displacement data of the device from the resting location using the movement data from the accelerometer.
In the system, the power application may further provide instructions to the microprocessor to place the electronic device in one of a plurality of power consumption modes by monitoring signals from the accelerometer and by changing modes within the plurality of power consumption modes based on the signals; the plurality of power consumption modes may include the low power state, the higher power state, at least an off state and a fully on state; and the low power state may be a partially-off state that consumes less power than the fully on state and more power than the off state.
In the system, the power application may further provide instructions to the microprocessor to place the electronic device in the higher power state when the electronic device is in the stationary state at the resting location and the accelerometer provides a second signal indicating a subsequent movement of the electronic device from the resting location.
In the system, the power application may further provide instructions to the microprocessor to: track a time that the electronic device is in the higher power state after placing the electronic device in the higher power state; monitor for receipt of a non-use signal from the accelerometer indicating an intent to return to the lower power state; and monitor for receipt of a return signal from the accelerometer indicating return of the electronic device at or near the resting location.
In the system, the power application may further provide instructions to the microprocessor to place the electronic device in the low power state from the higher power state and deactivate the backlight when a predetermined length of time of non-use of the electronic device passes or when a predetermined time for shut-off passes.
In the system, the power application may activate another element in the electronic device after receiving the first signal when the electronic device is placed from the low power state to the higher power state.
In the system, the power application may turn off the backlight for the electronic device when the electronic device is in the low power state.
In a second aspect, a method of selectively placing an electronic device in one of a plurality of power consumption modes is provided. The method comprises: monitoring an accelerometer in the electronic device for movement data; and placing the electronic device in a low power state from a higher power state upon determining from the movement data that the electronic device has been returned to around a resting location where the electronic device was previously in a stationary state from a first location that is in a spaced relationship to the resting location.
The method may further comprise: placing the electronic device in the higher power state from the low power state after the electronic device is stationary and at the resting location and after the accelerometer provides a signal indicating movement of the electronic device from the resting location; and activating a backlight for the electronic device when the electronic device is in the higher power state.
In the method, the low power state may be a partially-off state; and the backlight may have a variable intensity.
The method may further comprise placing the electronic device in one of a plurality of power consumption modes by evaluating the movement data and by changing modes within the plurality of power consumption modes based on the movement data.
In the method, the plurality of power consumption modes may further include an off state, a fully on state; and the low power state may consume less power than the fully on state and more power than the off state.
The method may further comprise turning off the backlight when the electronic device is in the low power state.
The method may further comprise: tracking a time that the electronic device is in the higher power state; and placing the electronic device in the low power state from the higher power state when a predetermined length of time of non-use of the electronic device passes or when a predetermined time for shut-off passes.
In a third aspect, a portable electronic device is provided. The device comprises: a microprocessor; an accelerometer; and a power application operating on the microprocessor and providing instructions to the microprocessor to place the electronic device in a low power state from a higher power state upon determining from movement data generated by the accelerometer that the electronic device has been returned to around a resting location where the electronic device was previously in a stationary state from a first location that is in a spaced relationship to the resting location.
In the portable electronic device, the power application may further provide instructions to the microprocessor to calculate displacement data of the device from the resting location using the movement data from the accelerometer.
In the portable electronic device, the power application may further provide instructions to the microprocessor to place the electronic device in one of a plurality of power consumption modes by monitoring signals from the accelerometer and by changing modes within the plurality of power consumption modes based on the signals; and the plurality of power consumption modes may include the low power state, the higher power state, at least an off state and a fully on state; and the low power state may be a partially-off state that consumes less power than the fully on state and more power than the off state.
In the portable electronic device, the power application may further provide instructions to the microprocessor to place the electronic device in the higher power state when the electronic device is in the stationary state at the resting location and the accelerometer provides a second signal indicating a subsequent movement of the electronic device from the resting location.
In the portable electronic device, the power application may further provide instructions to the microprocessor to: track a time that the electronic device is in the higher power state after placing the electronic device in the higher power state; monitor for receipt of a non-use signal from the accelerometer indicating an intent to return to the lower power state; and monitor for receipt of a return signal from the accelerometer indicating return of the electronic device at or near the resting location.
In another aspect, a power management system for an electronic device is provided. The system comprises: a microprocessor controlling the device; an accelerometer; and a power application operating on the microprocessor to place the device in one of a plurality of power consumption modes by monitoring signals from the accelerometer and changing modes within the plurality of power consumption modes based on the signals. The power application provides instructions to the microprocessor to place the device in a higher power state than a low power state when the device is in a stationary state at a resting location and the accelerometer provides a first signal indicating a subsequent movement of the device from the resting location to a first location in a spaced relationship from the resting location and then activate a backlight for the device when placed in the higher power state; and to place the device in the low power state from the higher power state upon receipt of a signal indicating return of the device from the first location to around the resting location, the signal being derived from data from the accelerometer, and then deactivate the backlight.
In the system, the power consumption modes may include the low power state, the higher power state, at least an off state, a fully on state; and the low power state may consume less power than the fully on state and more power than the off state.
In the system, the power application may turn off the backlight for the device when the device is the low power state.
In the system, the low power state may be a partially-off state.
In the system, the power application may activate another element in the device after receiving the first signal when the device is placed from the low power state to the higher power state.
In the system, the backlight may have a variable intensity set by the power application.
In the system, after placing the device in the higher power state, the power application may further track a time that the device is in the higher power state, may monitor for receipt of a non-use signal from the sensor indicating an intent to return to the lower power state and may monitor for receipt of a return signal from the sensor indicating return of the device at or near the resting location.
In the system, the signal indicating return of the device to around the resting location may be based on displacement signals provided by the accelerometer.
In yet another aspect, a method of selectively placing an electronic device in one of a plurality of power consumption modes is provided. The method comprises: monitoring a sensor in the device for a first signal indicating movement of the device from a resting location when the device is operating in both a low power state and a stationary state; placing the device in a higher power state from the low power state when the device is stationary and the sensor provides a first signal indicating subsequent movement of the device and then activating a backlight for the device when the device is in the higher power state; and placing the device in the low power state from the higher power state upon receipt of a signal from the sensor indicating return of the device at or near the resting location and deactivating the backlight.
In the method, the power consumption modes may further include an off state, a fully on state; and the low power state may consume less power than the fully on state and more power than the off state.
The method may further comprise turning off the backlight system when the device is the low power state.
In the method, the sensor may be an accelerometer and the signal indicating return of the device to around the resting location may be based on displacement signals provided by the accelerometer.
In the method, the sensor may be selected from a motion detector, an accelerometer, a switch and a proximity sensor.
The method may further comprise: while the device is in the higher power state, tracking a time that the device is in the higher power state, monitoring for receipt of a non-use signal from the sensor indicating an intent to return to the lower power state and monitoring for receipt of a return signal from the sensor indicating return of the device at or near the resting location.
The method may further comprise upon activating the backlight system upon detection of the first signal, activating another element in the device.
In the method, the low power state may be a partially off state.
In still another aspect, a handheld mobile communication device is provided. The device comprises a casing for housing a display and a keyboard; a microprocessor controlling aspects of the keyboard and display; a passive usage sensor; and a power application operating on the microprocessor. The power application monitors the usage sensor for a signal indicating movement of the device from a resting location when the device is in a low power mode and upon detection of the signal for providing power to at least one additional element in the device.
In the device, the passive usage sensor may be selected from a motion detector, an accelerometer, a switch and a proximity sensor.
In the device, the power application may automatically turn off the element after a preset amount of time of being activated has passed.
In the device, the element may be a backlighting system for the display.
In the device, the backlighting system may have a variable intensity set by the power application.
In the device the passive usage sensor may be the accelerometer. Further, the power application tracks: when the device is in the low power mode in the resting location; when the accelerometer provides signals indicating movement of the device from the resting location; and when the accelerometer provides signals indicating return of the device to the resting location.
In the device, the passive usage sensor may be the proximity sensor. Further, the power application tracks: when the device is in the low power mode in the resting location; when the proximity sensor provides signals indicating movement of the device from the resting location; and when the proximity sensor provides signals indicating return of the device to the resting location.
In a further aspect, a method for selectively activating at least one element for a handheld mobile communication device is provided. The method comprises: monitoring for usage of the device when the device is in a resting location by monitoring for activation of a sensor which provides sensing information which infers of usage of the device; and upon inferring activation of the device from the sensor, providing power to at least one additional element in the device.
The method may select the sensor from a motion detector, an accelerometer, a switch and a proximity sensor.
In the method, the additional element may be turned off after a preset amount of time of being activated has passed.
In the method, the additional element may be a backlighting system for a display associated with the device.
In the method, the sensor may be an accelerometer. Further, the method comprises tracking: when the device is in the low power mode in the resting location; when the accelerometer provides signals indicating movement of the device from the resting location; and when the accelerometer provides signals indicating return of the device to the resting location.
In the method the sensor may be a proximity sensor. Further, the method comprises tracking: when the device is in the low power mode in the resting location; when the proximity sensor provides signals indicating movement of the device from the resting location; and when the proximity sensor provides signals indicating return of the device to the resting location.
In other aspects various combinations of sets and subsets of the above aspects are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other aspects of the disclosure will become more apparent from the following description of specific embodiments thereof and the accompanying drawings which illustrate, by way of example only, the principles of the disclosure. In the drawings, where like elements feature like reference numerals (and wherein individual elements bear unique alphabetical suffixes):
FIG. 1 illustrates a block diagram of an exemplary mobile device that incorporates an embodiment of the disclosure; and
FIG. 2 illustrates a flow diagram of selectively activating and then selectively deactivating the device associated with the embodiment of FIG. 1 .
DETAILED DESCRIPTION
The description which follows, and the embodiments described therein, are provided by way of illustration of an example, or examples, of particular embodiments of the principles of the present disclosure. These examples are provided for the purposes of explanation, and not limitation, of those principles and of the disclosure. In the description, which follows, like parts are marked throughout the specification and the drawings with the same respective reference numerals.
FIG. 1 illustrates a handheld mobile communication device 10 including a housing, an input device (e.g. keyboard 14 A or thumbwheel 14 B) and an output device (a display 16 ), which is preferably a graphic Liquid Crystal Display (LCD). Other types of output devices may alternatively be utilized. A processing device (a microprocessor 18 ) is shown schematically in FIG. 1 as coupled between keyboard 14 A, thumbwheel 14 B, display 16 and a series of other internal devices to device 10 . The microprocessor 18 controls the operation of the display 16 , as well as the overall operation of the device 10 , in response to actuation of keys on the keyboard 14 A or thumbwheel 14 B by a user. Exemplary microprocessors for microprocessor 18 include Data 950 (trade-mark) series microprocessors and the 6200 series microprocessor, both available from Intel Corporation.
Physically for device 10 , its housing may be elongated vertically, or may take on other sizes and shapes (including clamshell housing structures). The keyboard may include a mode selection key, or other hardware or software for switching between text entry and telephony entry.
Although not shown as a separate item, when display 16 is implemented as a LCD, a backlighting system is almost invariably used to assist in the viewing display 16 , especially under low-light conditions. A typical backlighting system comprises a series of LEDs and a controller to control activation of the LEDs. Depending on a brightness level selected for display 16 , all or some of the LEDs may be powered in a full duty cycle or a duty-cycle approaching 0%.
In addition to the microprocessor 18 , other internal devices of the device 10 are shown schematically in FIG. 1 . These devices include: a communication subsystem 100 , a short-range communication subsystem 102 , keyboard 14 A, thumbwheel 14 B and display 16 . Other input/output devices include a set of auxiliary I/O devices 106 , a serial port 108 , a speaker 110 and a microphone 112 . Memory for device 10 is provided in flash memory 116 and Random Access Memory (RAM) 118 . Finally, additional sensor 120 and various other device subsystems (not shown) are provided. The device 10 is preferably a two-way radio frequency (RF) communication device having voice and data communication capabilities. In addition, device 10 preferably has the capability to communicate with other computer systems via the Internet.
Operating system software executed by the microprocessor 18 is preferably stored in a computer readable medium, such as flash memory 116 , but may be stored in other types of memory devices, such as read only memory (ROM) or similar storage element. In addition, system software, specific device applications, or parts thereof, may be temporarily loaded into a volatile store, such as RAM 118 . Communication signals received by the mobile device may also be stored to RAM 118 .
Microprocessor 18 , in addition to its operating system functions, enables execution of software applications on device 10 . A set of software applications that control basic device operations, such as a voice communication module 130 A and a data communication module 130 B, may be installed on the device 10 during manufacture or downloaded thereafter. Cell mapping module 130 C may also be installed on device 10 during manufacture. As well, additional software modules, illustrated as another software module 130 N, which may be, for instance, a personal information manager (PIM) application, may be installed during manufacture or downloaded thereafter into device 10 . PIM application is preferably capable of organizing and managing data items, such as e-mail messages, calendar events, voice mail messages, appointments, and task items. PIM application is also preferably capable of sending and receiving data items via a wireless network 140 . Preferably, data items managed by PIM application are seamlessly integrated, synchronized and updated via wireless network 140 with device user's corresponding data items stored or associated with a host computer system.
Communication functions, including data and voice communications, are performed through the communication subsystem 100 , and possibly through the short-range communication subsystem 102 . Communication subsystem 100 includes receiver 150 , transmitter 152 and one or more antennas, illustrated as receive antenna 154 and transmit antenna 156 . In addition, communication subsystem 100 also includes processing module, such as digital signal processor (DSP) 158 and local oscillators (LOs) 160 . The specific design and implementation of communication subsystem 100 is dependent upon the communication network in which device 10 is intended to operate. For example, communication subsystem 100 of the device 10 may be designed to operate with the Mobitex (trade-mark), DataTAC (trade-mark) or General Packet Radio Service (GPRS) mobile data communication networks and also designed to operate with any of a variety of voice communication networks, such as Advanced Mobile Phone Service (AMPS), Time Division Multiple Access (TDMA), Code Division Multiple Access CDMA, Personal Communication Service (PCS), Global System for Mobile Communication (GSM), etc. Other types of data and voice networks, both separate and integrated, may also be utilized with device 10 .
Network access requirements vary depending upon the type of communication system. For example, in the Mobitex (trade-mark) and DataTAC (trade-mark) networks, mobile devices are registered on the network using a unique Personal Identification Number (PIN) associated with each device. In GPRS networks, however, network access is associated with a subscriber or user of a device. A GPRS device therefore requires a subscriber identity module, commonly referred to as a Subscriber Identity Module (SIM) card, in order to operate on a GPRS network.
When required network registration or activation procedures have been completed, device 10 may send and receive communication signals over communication network 140 . Signals received from communication network 140 by the receive antenna 154 are routed to receiver 150 , which provides for signal amplification, frequency down conversion, filtering, channel selection, etc., and may also provide analog to digital conversion. Analog-to-digital conversion of received signals allows the DSP 158 to perform more complex communication functions, such as signal demodulation and decoding. In a similar manner, signals to be transmitted to network 140 are processed (e.g., modulated and encoded) by DSP 158 and are then provided to transmitter 152 for digital to analog conversion, frequency up conversion, filtering, amplification and transmission to communication network 140 (or networks) via the transmit antenna 156 .
In addition to processing communication signals, DSP 158 provides for control of receiver 150 and transmitter 152 . For example, gains applied to communication signals in receiver 150 and transmitter 152 may be adaptively controlled through automatic gain control algorithms implemented in DSP 158 .
In a data communication mode, a received signal, such as a text message or web page download, is processed by the communication subsystem 100 and is input to microprocessor 18 . The received signal is then further processed by microprocessor 18 for an output to the display 16 , or alternatively to some other auxiliary I/O devices 106 . A device user may also compose data items, such as e-mail messages, using keyboard 14 A, thumb-wheel 14 B and/or some other auxiliary I/O device 106 , such as a touchpad, a rocker switch or some other type of input device. The composed data items may then be transmitted over communication network 140 via communication subsystem 100 .
In a voice communication mode, overall operation of device 10 is substantially similar to the data communication mode, except that received signals are output to speaker 110 , and signals for transmission are generated by microphone 112 . Alternative voice or audio I/O subsystems, such as a voice message recording subsystem, may also be implemented on device 10 . In addition, display 16 may also be utilized in voice communication mode, for example, to display the identity of a calling party, the duration of a voice call, or other voice call related information.
Short-range communication subsystem 102 enables communication between device 10 and other proximate systems or devices, which need not necessarily be similar devices. For example, the short-range communication subsystem may include an infrared device and associated circuits and components, or a Bluetooth (trade-mark) communication module to provide for communication with similarly-enabled systems and devices.
Powering the entire electronics of the mobile handheld communication device is power source 170 . Preferably, the power source 170 includes one or more batteries. More preferably, the power source 170 is a single battery pack, especially a rechargeable battery pack.
Power switch 172 provides an “on/off” switch for device 10 . Upon activation of power switch 172 a process operating on device 10 is initiated to turn on device 10 and preferably initiate all functionality of device 10 . Upon deactivation of power switch 172 , another process is initiated to turn off device 10 . Power to device 10 may also be controlled by other devices and by internal software applications, as described further below.
Device 10 can be placed in one of several power consumption modes including: a fully on mode, a partially on mode and a fully off mode. In the fully off (deep sleep) mode, power is provided to only a minimal set of component to enable device 10 to operate. These components typically include those which at a minimum, provide power to microprocessor 18 and its related memory, clocks and other devices to allow device 10 to maintain its internal clock, software applications and data, and recognize a stimulus (e.g. activation of the power on button) to revive device 10 from its fully off/deep sleep mode. In the partially on mode one or more functionalities of device 10 are either disabled or reduced. For example, one or both of communication system 100 and communication subsystem 102 may be disabled. Also, the backlighting system for display 16 may be reduced in intensity; to conserve power, the backlight system is either set to activate the LEDs at a low duty cycle frequency or not activate the LEDs at all. Other internal devices of device 10 can also be programmed to operate in different power modes. It will be appreciated that there may be several partially on modes where different sets of functionalities may be enabled/disabled in each mode.
In particular, device 10 can be placed into a sleep mode, wherein a schedule can be provided to device 10 to define “on” and “off” cycles for device 10 depending on the time of day and the date. Therein, the user accesses a programming menu in device 10 and accesses a scheduler, then enters data for an activation cycle using keyboard 14 A. Alternatively, such data can be downloaded to device 10 from a remote source. Typically, programming for the sleep mode is achieved through a programming menu, power application generated on display 16 . The menu provides text inviting the user to enter “on” and “off” times in appropriate weekday fields as activation boundaries for weekdays. Text on the screen may also invite the user to select what level of power is to be provided to device 10 during a sleep mode. Once the data is entered by the user and submitted to device 10 from the menu, application processes the time data and updates or generates an activation cycle for device 10 . Thereafter, power application monitors its internal clock to determine the current time and date and automatically turns on and off identified elements in device 10 according to the time data stored for the activation cycle. The deployment and implementation of the scheduler may be implemented in any programming language.
Also, device 10 can have a built in program routine to automatically move from one power state to a lower power state when a predetermined event occurs. Such an event can be considered to be an “auto-off” event for device 10 . For example, subsystem 102 is enabled and no message is received after a certain set time limit, power application can be set to cause device 10 to move to a lower power mode and disable power to subsystem 102 . Signals and absence of signals from other elements in device 10 can be used by the routine to change the power state of device 10 . To allow entry of such “auto-off” events, device 10 provides a similar user interface of menu screen(s) on display 16 .
The embodiment provides a system and method activating device 10 from a lower power mode (e.g. a sleep mode) to a higher power mode (e.g. a fully on mode) by inferring intended use of device 10 , preferably without monitoring for activation of power switch 172 or any specific activation of any other key or input device which the user typically specifically activates on device 10 .
To that end, device 10 has also has one or more sensors 120 to detect its state of activation. Such sensors are passive, in a sense that the user does not have to manually activate the sensor to cause device 10 to activate. Such sensors are selected to detect secondary conditions which are used to infer that device 10 is being used. For example, one type of sensor 120 is an activation sensor providing an indication of movement or usage of device 10 . As such, when the activation sensor is tripped, the program operating in device 10 makes a determination that device 10 is about to be used and activates one or more of its functional components which are currently not active. It is notable that the activation of the components is done without the user having to specifically press the power switch 172 , depress any key in keypad 14 A or spin thumbwheel 14 b.
The activation sensor may be a mercury switch, an accelerometer or any other motion sensing device which can be incorporated within device 10 . If sensor 120 is implemented as a mercury switch (or a comparable tilt switch), then electrical signals generated from the switch are provided to microprocessor 18 and software operating on microprocessor 18 is provided to detect signals from the switch and to determine whether the signals received mean that device 10 is at rest or is moving.
If sensor 120 is implemented as an accelerometer, signals therefrom can be used by the power application to detect motion and to detect a displacement vector of device 10 , since accelerometers, as force measuring devices, provide force information which can be used to derive displacement information using mathematical integration methods. As such, signals from the accelerometer can be used to detect when device 10 is moved from its resting location to an active position and when device 10 is returned to its resting location. Such numerical data integration techniques can be implemented in the power application as an appropriate function, using programming techniques known in the art.
Alternatively still, sensor 120 may be a spring loaded switch which is biased to be in one position (either open or closed) when device 10 is placed flatly on a surface (e.g. flat on its back, if sensor 120 is a spring-loaded switch located on the back of device 10 ) and is biased to be in a second position (either closed or open) when device 10 is lifted from the surface. In still another sensing arrangement, if device 10 is electrically connected to a docking station, allowing device 10 to communicate with another device such as a computer (not shown), then the application can detect when device 10 is docked and undocked in its cradle. Other embodiments may use wireless systems, such as Bluetooth-enabled (trade-mark) systems, to detect when device 10 is near a detecting or docking station. Other types of sensors known in the art may be used for sensor 120 . For each type of sensor 120 , depending on its sensing dynamics, one detection of one state will indicate that device 10 is being moved and detection of another state will indicate that device 10 has stopped being moved. It will be appreciated that for each of the different types of sensors for motion sensor 120 , an appropriate software interface is provided to enable to the power application to register the status of sensor 120 .
Alternatively, sensor 120 is a light sensor which is used by power application to detect when it is in a lit, dimly lit or unlit environment or when it is nighttime or daylight environment. The power application may also use data from sensor 120 with its data on the current time, date and location of device 10 to determine ambient daylight conditions for device 10 .
In other embodiments, multiple sensors 120 may be provided and the power application may provide different emphasis on signals provided from different sensors 120 .
In order to utilize signals from sensor(s) 120 , power application is embodied in a software application (for example, as one of the software applications described above) enabling it to selectively control power of one or more internal elements of device 10 , including, for example, display 16 , keyboard 14 A, thumbwheel 14 B, microphone 112 , short range communication module 102 and communication subsystem 100 . The power application operates on microprocessor 18 , has access to the system clock of device 10 and can selectively provide power control signals to one or more of the internal elements. Such power control signals include signals: to turn off the element completely; activate the element in a full power, full capability mode; and activate the element in a mode which provides capabilities somewhere between full power and no power.
The power application operates in several modes. A first mode is when device 10 is in a full power mode; therein the power application takes no substantive activity and waits for device 10 to be de-activated into a lower powered state, either through an automatic shut-off routine (e.g. after a predetermine time of non-use or when a predetermined time for shut-off passes) or active shut-off of device 10 by the user. Upon detection of de-activation of device 10 , a second mode monitors for continually usage of device 10 for one of the following conditions: active reactivation of device 10 (e.g. through activation of power switch 172 , pressing of a key on keypad 14 A or scrolling of thumbwheel 14 B); or a signal from sensor(s) 120 . If the second condition is detected, then device 10 is brought to a higher power state for a preset amount of time.
The second step is to monitor for activation of device 10 when it is in a sleep mode or any power mode which is not the full power mode. One monitoring process waits for an active activation of device 10 to occur, e.g. monitoring for activation of power key 172 , a key on keyboard 14 A or thumbwheel 14 B.
For the second step, one technique for detecting when device 10 is being used is to infer usage when device 10 is being moved using signals from sensor(s) 120 . If the user subsequently picks up device 10 , sensor(s) 120 detect movement from a resting location. As such, for example, in use, a user can simply pick up device 10 when it is in its dormant state and as sensor 120 recognizes movement of device 10 , device 10 can be brought to a higher power state.
Upon detection of activation, device 10 can power up backlighting for display 16 , can power up one or more subsystems 102 or can power up one or more other internal elements of device 10 .
Upon detection of use of device 10 , power application begins a timer which is used to track time after activation and monitors for activity of device 10 . After a predetermined length of time of non usage (e.g. 5, 10, 15, 20, 30, 45, 60 minutes or more), power application can selectively mark device 10 as not being used and can place device 10 in a lower power consumption mode. The absence of use may be determined by monitoring the presence or absence of an event. For example the events may include: activation or non-activation of a key on keyboard 14 A or scrolling, depressing or non-activation of thumbwheel 14 B, movement or non-movement of device 10 , active turn off of device 10 , docking or undocking of device 10 from a docking device and return of device 10 to its resting location. The detection of use and then the detection of absence of use would complete one activation cycle for device 10 . Power application tracks the time and duration of this activation cycle.
It will be appreciated that with the application, a user can simply pick up device 10 , have it power on one or more previously dormant functions, e.g. backlighting for display 16 , have the function operational for a preset limited period of time, (e.g. a number of seconds or a number of minutes), then have the function return to its dormant state preferably without having to specifically activate then deactivate power switch 172 .
After a certain predetermined period of non use, or if sensor 120 is an accelerometer, after detection that device 10 has been returned to its initial location when it in its dormant state, application can then place device 10 into a dormant state.
Referring now to FIG. 2 , further detail is provided on the operation of the second mode of power application, where algorithm 200 is shown. After start process 202 , if device 10 is in a full power mode, then power application waits for it to move to a partially on or fully off power mode. See step 204 . Then, once it has left the full power mode, in step 206 , power application waits for activation of device 10 . In step 208 , if activation of device 10 is caused by an active condition, power application returns to step 204 . In step 210 , if activation is caused by a passive condition detected on device 10 , then device 10 is placed in an conditionally-activated state. In the conditionally-activated state one or more elements of device 10 is activated and a timer is started. In step 212 , upon a timeout of the timer or a off condition of device 10 , power application places device 10 to a lower power state. As noted earlier, preferably, the conditionally-activated state is a time limited state. As such, in step 212 , the power application tracks a timer to see how long it has been in the conditionally-activated state. Once the time limit expires, then the elements activated are turned off completely or put into a lower power mode. Alternatively, the activated state may be ended by the detection of a further signal from sensor(s) 120 or another element, such as from keypad 14 A, power switch 172 , thumbwheel 14 B or detection of an “auto-off” event. Alternatively still, a signal from sensor(s) 120 can by used to infer that more time is needed for the conditionally-activated state and detection of such signal can be used to reset the timer.
The timer is implemented in software using the internal clock available from microprocessor 18 and data for the timer is stored in memory 116 . It will be appreciated that algorithm 200 may be implemented as a series of interrupt routines, thereby allowing other applications to operate concurrently with it in a real time manner. Other implementations providing real time detection and monitoring of usage may be used.
In other embodiments, when power application is in the conditionally-activated state, if another movement is detected by sensor 120 or if power switch 172 is activated, device 10 may be placed into a full power mode, and power application can then terminate.
Although the disclosure has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the scope of the disclosure as outlined in the claims appended hereto. | The disclosure provides a system and method for managing power and activation of a communication device. The system comprises: a microprocessor controlling the electronic device; an accelerometer; and a power application operating on the microprocessor. The application provides instructions to the microprocessor to place the electronic device in a low power state from a higher power state upon determining from movement data generated by the accelerometer that the electronic device has been returned to around a resting location where the electronic device was previously in a stationary state from a first location that is in a spaced relationship to the resting location. | 8 |
This is a division of application Ser. No. 801,453, filed Nov. 25, 1985, now U.S. Pat. No. 4,707,034, issued Nov. 17, 1987.
BACKGROUND OF THE INVENTION
In the manufacturing of hub sleeve members for bicycle hubs it is necessary to provide on the radial inner face of the hub sleeve torque transmission teeth for torque transmission from a gear unit provided inside the hub sleeve to the hub sleeve itself with the air of driving the bicycle rear wheel. The manufacturing costs relating to the provision of the torque transmission teeth are a considerable factor within the total manufacturing costs of the hub sleeve.
STATEMENT OF THE PRIOR ART
In known bicycle hubs the hub sleeve is manufactured from a cold-deformed solid blank which has been machined on all sides. The torque transmission teeth provided integrally in the hub sleeve for cooperation with drive ratchet pawls are produced by a broaching operation or by a slotting operation. Both processes require a disproportionately high expense for special tools and manufacturing costs in total. The possibility exists of arranging a separate annular part fast in rotation in the hub sleeve which comprises the internal ratchet and per se is somewhat simpler to produce. Such an annular part however constitutes an additional component and furthermore requires a rotation-fast connection with the hub sleeve. The expense in such an arrangement is likewise not inappreciable.
From German `Offenlegungsschrift` No. 2,906,627.1 it has been known to constitute a hub sleeve from a plurality of sheet metal members obtained by drawing operations. In this known embodiment a cylindrical middle section of one of the constituents is provided with stamped torque transmission teeth. The stamping of sheet metal such as to obtain torque transmission teeth is relatively easy in view of the small wall thickness of sheet metal. However the manufacturing of hub sleeves from sheet metal constituents raises other problems which result from small wall thickness which is a necessary consequence of using drawn sheet metal components.
OBJECT OF THE INVENTION
This invention relates to the type of hub sleeves which have a considerable wall thickness of e. g. 3 to 5 mm and more particularly 3 to 4 mm and which are profiled in such a way at their inward and/or outward face as to have longitudinal sections of different wall thickness. This is the type of hub sleeve in which in the past one has produced the torque transmission teeth exclusively by cutting operations like broaching and slotting operations as mentioned above. It is the object of the present invention to provide in this type of hub sleeve the torque transmission teeth in a more economical way than up to now.
It is a further object of the invention to combine the advantages of solid-type hub sleeves with relatively large wall thickness and manufactured by cold-swaging or forging with the advantages of the less expensive method of teeth generation by stamping.
SUMMARY OF THE INVENTION
A hub sleeve for a bicycle hub comprises a main hub sleeve member with an axis, a radially inward face having a radially inner profile line and a radially outward face having a radially outer profile line. At least one of said radially inner profile line and said radially outer profile line has deviations from a straight line such as to define longitudinal sections of said main sleeve member with differences in wall thickness. Ball bearing faces and at least one circular arrangement of torque transmission teeth are integrally formed with the main hub sleeve member at said radially inward face. The torque transmission teeth are formed by radially inward dislocations of material of said main hub sleeve member.
With this configuration inter alia the advantage is achieved that with a very economical method for swarfless production of the toothing in the interior of the solid hub sleeve, which is usable for single-ratio and multi-ratio hubs, properties important to functioning such for example as accuracy of dimension and form and also that of an attractive external configuration as a whole can be achieved.
This invention further relates to a method of manufacturing a main hub sleeve member as defined above. According to this method a raw member is profiled by forging or cold-swaging such as to approximately obtain the radially inward and radially outward faces. At least the ball bearing faces are machined by a cutting operation. The torque transmission teeth are hereupon obtained by a stamping operation using at least one radially outward stamp tool radially movable against the radially outward face of the main hub sleeve member and a support unit applied to the radially inward face and being provided with at least one recess receiving a dislocation of material. The product and the method of this invention are of particular importance in such hub sleeve configurations in which the longitudinal section of the main hub sleeve member accommodating the torque transmission teeth has an internal diameter larger than a further longitudinal section on one or both axial sides of the section accommodating the torque transmission teeth. With such a configuration it is particularly difficult to obtain the torque transmission teeth by broaching or slotting.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be explained in greater detail below by reference to the example embodiment. In detail:
FIG. 1 shows a solid hub sleeve with tools for the swarfless production of an internal ratchet, in partial longitudinal section;
FIG. 2 shows a cross-section along the line II--II in FIG. 1 through the hub sleeve with diagrammatic representation of the swarfless production of the integral internal ratchet;
FIG. 3 shows a solid hub sleeve with other tools for swarfless production of an integral internal ratchet in an undercut region of the hub sleeve;
FIG. 4 shows a cross-section along the line IV--IV of FIG. 3;
FIG. 5 shows a solid hub sleeve with tools for the swarfless production of an integral internal ratchet in an undercut region of the hub sleeve;
FIG. 6 shows a cross-section along the line VI--VI of FIG. 5;
FIG. 7 shows a solid hub sleeve with another swarfless style of production of an integral internal ratchet in cross-section; and
FIG. 8 shows a solid hub sleeve with another swarflessly formed, integral internal ratchet, in cross-section.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the FIGS. 1 designates an only partially illustrated main hub sleeve member which has been produced from a solid blank by cold-swaging and/or forging and machining such as turning. The formed-on spoke flanges are designated by 2. In the region axially beside the spoke flange 2 the main hub sleeve member 1 has a formed-in internal ratchet 3, i.e. a circumferential arrangement of torque transmitting teeth, which serves for example for cooperation with radially outwardly acting pawls (not shown here) on a concentric pawl carrier part (likewise not shown). The main hub sleeve member 1 is provided with a ball bearing face 10 which has been obtained by a turning operation after the cold-swaging and/or forging operation.
The main hub sleeve member 1 as shown in partial longitudinal section in FIG. 1 surrounds in the interior a one-piece support mandrel 5 which comprises--distributed on the circumference--recesses 6 which correspond to the negative form of the teeth to be formed swarflessly in the radially inward face 11 of the main hub sleeve member 1. To the production tool there further pertains a set of stamp tools 4 which, arranged in distribution in conformity with the pitch of the teeth to be formed integrally, act from radially outwards upon the radially outward face 12 of the main hub sleeve member 1 and, as may be seen, press out torque transmission teeth 3 inwards from the face 11 of the main hub sleeve member 1, and may be seen clearly especially from FIG. 2.
In the axial region of the inner ratchet 3 to be formed the main hub sleeve member 1 is made cylindrically smooth in its external form and has a constant wall thickness. The stamp tools 4 press the material of the main hub sleeve member 1 inwards into the corresponding recesses 6, serving as negative form, of the support mandrel 5, whereby the desired torque transmission teeth of the internal ratchet 3 are integrally formed.
The production of internal torque transmission teeth in a main hub sleeve member in the axial region of an undercut is shown by the example of embodiment according to FIGS. 3 and 4. FIG. 3 here shows the main hub sleeve member 1 in which an internal ratchet is formed in a longitudinal section S 1 of larger internal diameter as compared with adjacent longitudinal sections S 1 and S 3 of smaller internal diameter. More particularly the ratchet if fromed adjacent a conical control face 1a which is used for controlling the engagement of torque transmission pawls with the torque teeth 3 by axial movement of the pawls. Here as support a radially expandable support unit 5a is used which comprises recesses 6 distributed on its outer surface as negative form of the torque transmission teeth 3 to be formed swarflessly in each segment of the support unit 5a. The segments of the support unit 5a are radially movable into their operative position by a spreading core 7.
As explained above, for the production of the torque transmission teeth in the region of undercuttings of the hub sleeve an arrangement of stamp tools can be used together with a support unit, namely an expanding mandrel for arrangement in the hub sleeve.
It is, however, also possible to form the support member so that the main hub sleeve member is supported in each case in the region of only one torque transmission tooth and the torque transmission teeth are formed individually out of the wall of the main hub sleeve member. Such a method can contribute substantially to the simplification of the tool construction.
In FIGS. 5 and 6 such a method is shown. A solid hub sleeve 1 with integral torque transmission teeth 3 for arrangement axially behind an undercutting may be seen. In the forming of the ratchet teeth the main hub sleeve member is supported in the region of each one torque transmission tooth by means of a support mandrel 5b for positioning in accordance with the ratchet pitch.
The form in each case of the torque transmission tooth to be pressed out of the main hub sleeve member is freely selectable and can be adapted by modification of the stamp tools 4 and of the support mandrel 5 to the function and also to the production method.
FIG. 7 shows internal torque transmission teeth 3 in a solid main sleeve member 1 where the individual torque transmission teeth have approximately the cross-sectional form of a bilaterally acting wedge spline. On the other hand FIG. 8 shows a solid main hub sleeve 1 with saw-tooth shaped toothings 3'.
The wall thickness of the main hub sleeve member 1 in the longitudinal section S 1 is about 2 to 4 mm, preferably about 3,5 mm.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
The reference numerals in the claims are only used for facilitating the understanding and are by no means restrictive. | A hub sleeve for a bicycle hub is manufactured by cold-swaging or forging. The hub sleeve is integrally provided with ball bearing faces and with internal torque transmission teeth. The torque transmission teeth are obtained by radial dislocation of the wall material of the hub sleeve. | 8 |
This invention was made with government support awarded by the Office of Naval Research under contract No. N00014-86-K-0261. The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
This invention relates generally to protection of underwater surfaces from fouling by aquatic organisms.
DESCRIPTION OF THE PRIOR ART
In marine, brackish, and freshwater environments, organisms collect, settle, attach, and grown on submerged structures. Organisms which do so can include algae, and aquatic animals, such as tunicates, hydroids, bivalves, bryozoans, polychaete worms, sponges, and barnacles. Submerged structures can include the underwater surfaces of ships, docks and piers, pilings, fishnets, heat exchangers, dams, piping structures, such as intake screens, and cooling towers. The presence of these organisms, known as the "fouling" of a structure, can be harmful in many respects. They can add to the weight of the structure, hamper its hydrodynamics, reduce its operating efficiency, increase susceptibility to corrosion, and degrade or even fracture the structure.
The common method of controlling the attachment of fouling organisms is by protecting the structure to be protected with a paint or coating which contains an antifouling agent. Exemplary antifouling coatings and paints are described in U.S. Pat. No. 4,596,724 to Lane, U.S. Pat. No. 4,410,642 to Layton, and U.S. Pat. No. 4,788,302 to Costlow. Application of a coating of this type inhibits the attachment, or "settling," of the organism, by either disabling the organism or providing it with an unattractive environment upon which to settle.
Of the fouling organisms noted above, barnacles have proven to be among the most difficult to control. Typically, commercial antifouling coatings and paints include a toxic metal-containing compound such as tri-n-butyl tin (TBT), or cuprous oxide, which leaches from the coating. Although these compounds exhibit moderate success in inhibiting barnacle settlement, they degrade slowly in marine environments, and therefore are ecologically harmful. In fact, TBT is sufficiently toxic that its release rate is limited by legislation in some countries.
Some experimental non-toxic compounds have been tested with limited success in barnacle settlement inhibition. See, e.g., Gerhart et al., J. Chem. Ecol. 14:1905-1917 (1988), which discloses the use of pukalide, epoxypukalide, and an extract produced by the octocoral Leptogorgia virgulata, to inhibit barnacle settlement, and Sears et al., J. Chem. Ecol. 16:791-799 (1990), which discloses the use of ethyl acetate extracts of the sponge Lissodendoryx isodictylais to inhibit settlement.
Japanese Patent Disclosure No. 54-44018A of Apr. 7, 1979 (Patent Application No. 52-109110 of Sep. 10, 1977, discloses gamma-methylenebutenolide lactone and alkyl gamma-methylenebutenolide lactone derivatives having the general structure ##STR1## wherein R 1 and R 2 are hydrogen or saturated or unsaturated alkyl groups of 1-8 carbon atoms. The compounds are natural products from terrestrial plants.
In view of the foregoing, it is an object of the present invention to provide an antifouling composition which is effective in inhibiting the settlement of fouling organisms on an underwater surface.
Another object of the present invention is to provide an antifouling paint or coating composition which is effective in protecting underwater structures from fouling by barnacles, and other aquatic organisms.
A further object is to provide structures which are effectively protected against fouling by aquatic organisms.
SUMMARY OF THE INVENTION
These and other objects are accomplished by the present invention which in one aspect comprises a composition for use as a marine or freshwater antifoulant comprising a protective carrier component functioning to release antifouling agent and, as an antifouling agent, at least one gamma lactone compound having a formula selected from the group consisting of ##STR2## wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , and R 13 are independently selected from the group consisting of hydrogen and (C 1 -C 10 ) alkyl.
A second aspect of the present invention comprises a method of protecting a marine or freshwater structure against fouling by marine or freshwater fouling organisms comprising applying at least one of said compounds on and/or into said structure.
Another aspect of the invention is a marine or freshwater structure protected against fouling organisms wherein said protection is afforded by at least one of said lactone compounds having been applied on and/or into said structure.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to controlling the attachment of unwanted organisms to submerged surfaces by contacting the organisms with at least one of said lactone compounds. It has been discovered that said lactone compounds inhibit the settlement of fouling organisms, particularly barnacles. As used herein, "settlement" refers the attachment of aquatic organisms to an underwater structure. Contacting an organism with one of said lactone compounds in the area adjacent a submerged surface prevents the settling of the organism on that submerged surface.
The preferred lactone compounds are selected from the group consisting of γ-decalactone; α-angelica lactone; α-santonin; α-methylene-γ-butyrolactone; coumaranone and alantolactone.
In the practice of the method of the present invention, the lactone antifouling compound may be contacted to the fouling organism by coating the object to be protected with a composition comprising the lactone antifouling compound, which then releases the compound into the aquatic environment immediately adjacent the external surfaces of the article, by including the antifouling compound within material formed into an aquatic article which then releases the compound, by releasing the compound directly into the aquatic environment surrounding the protected object, or by any other method wherein the compound contacts the organism prior to its attachment to the surface. As used herein, the term "contacting" means that an amount of antifouling compound sufficient to inhibit settlement of the organism on the surface of interest physically contacts the organism, whether by direct external contact, inhalation, respiration, digestion, inhibition, or any other process.
The amount of lactone compound to be used in the method will vary depending on a number of factors, including the identity of the antifouling compound, the identity of the organism to be inhibited, and the mode of contact. In addition, the rate at which the compound is released into the surrounding aquatic environment can be a major factor in determining both the effectiveness of the method and the duration of protection. If the compound is released too rapidly, it will be exhausted quickly, and the coating must be re-applied for the surface to be protected. If on the other hand the release rate of the antifouling compound is too slow, the concentration of the compound in the aquatic environment immediately surrounding the surface to be protected may be insufficient to inhibit settlement. Preferably, the antifouling compound is released into the environment adjacent the protected surface at the rate of between about 0.0001 and 1000 μg/cm 2 -hr, and more preferably is released at a rate of between about 0.01 and 100 μg/cm 2 -hr. It is preferred that the antifouling compounds be present in such a composition in a concentration by weight of between 0.001 and 50 percent, more preferably in a concentration of about 0.1 to 20 weight percent.
The organisms against which a surface can be protected by the present method can be any organism which can attach to a submerged surface. Exemplary organisms include algae, including members of the phyla chlorophyta and Phaeophyta, fungi, microbes, tunicates, including members of the class Ascidiancea, such as Ciona intestinalis, Diplosoma listerianium, and Botryllus sclosseri, members of the class Hydrozoa, including Clava squamata, Hydractinia echinata, Obelia geniculata, and Tubularia larnyx, bivalves, including Mytilus edulis, Crassostrea virginica, Ostrea edulis, Ostrea chilensia, and Lasaea rubra, bryozoans, including Ectra pilosa, Bugula neritinia, and Bowerbankia gracilis, polychaete worms, including Hydroides norvegica, sponges, and members of the class Cirripedia (barnacles), such as Balanus amphitrite, Lepas anatifera, Balanus balanus, Balanus balanoides, Balanus hameri, Balanus crenatus, Balanus improvisus, Balanus galeatus, and Balanus eburneus. Organisms of the genus Balanus are especially harmful to aquatic structures. Specific fouling organisms to which this invention is especially directed include barnacles, zebra mussels, algae, bacteria, diatoms, hydroids, bryzoa, ascidians, tube worms, and asiatic clams.
In addition to the lactone compound, the composition can comprise additional antifouling agent which may act in combination or synergistically; said additional antifouling agent can be, for example: manganese ethylene bisdithiocarbamate; a coordination product of zinc ion and manganese ethylene bis dithiocarbamate; zinc ethylene bisdithiocarbamate; zinc dimethyl dithiocarbamate; 2,4,5,6-tetrachloroisophthalonitrile; 2-methylthio-4-t-butylamino-6-cyclopropylamino-s-triazine; 3-(3,4-dichlorophenyl)-1,1-dimethyl urea; N-(fluorodichloromethylthio)-phthalimide; N,N-dimethyl-N'-phenyl-(N-fluorodichloromethylthio)-sulfamide; tetramethylthiuram disulfide; 2,4,6-trichlorophenyl maleimide; zinc 2-pyridinthiol-1-oxide; copper thiocyanate; Cu-10% Ni alloy solid solution; and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one.
The protective carrier component functioning to release antifouling agent can be a film-forming component, an elastomeric component, vulcanized rubber, or a cementitious component. The protective carrier component can be any component or combination of components which is applied easily to the surface to be protected, adheres to the submerged surface to be protected, and permits the release of the antifouling compound into the water immediately surrounding the coated surface. Different components will be preferred depending on the material comprising the underwater surface, the operation requirements of the surface, the configuration of the surface, and the antifouling compound. Exemplary film-forming components include polymer resin solutions. Exemplary polymer resins include unsaturated polyester resins formed from (a) unsaturated acids and anhydrides, such as maleic anhydride, fumaric acid, and itaconic acid; (b) saturated acids and anhydrides, such as phthalic anhydride, isophthalic anhydride, terephthalic anhydride, tetrahydrophthalic anhydride, tetrahalophthalic anhydrides, chlorendic acid, adipic acid, and sebacic acid; (c) glycols, such as ethylene glycol, 1,2 propylene glycol, dibromoneopentyl glycol, Dianol 33®, and Dianol 22®; and (d) vinyl monomers, such as styrene, vinyl toluene, chlorostyrene, bromostyrene, methylmethacrylate, and ethylene glycol dimethacrylate. Other suitable resins include vinyl ester-, vinyl acetate-, and vinyl chloride-based resins, elastomeric components, vulcanized rubbers, and urethane-based resins. The cementitious compounds are used to protect certain types of underwater structures, as are the elastomeric materials and vulcanized rubber.
The percentage of the lactone antifouling compound in the coating required for proper release of the compound into the aquatic environment surrounding the surface to be protected will vary depending on the identify of the antifouling compound, the identity of the film-forming component of the coating and other additives present in the coating which may affect release rate. As described above, the release rate of the antifouling compound can be a major factor in determining both the effectiveness of the method and the duration of protection. It is preferred that the coating be released into the surrounding water at a rate of between about 0.0001 and 1,000 μg/cm 2 -hr; more preferably, the compound comprises between about 0.01 and 100 μg/cm 2 -hr. Preferably, the antifouling compound comprises between about 0.001 and 80 percent of the coating by weight, and more preferably comprises between 0.01 and 20 percent of the coating.
Those skilled in this art will appreciate that a coating of the present invention can comprise any number of forms, including a paint, a gelcoat, or varnish, and the like. The coating can include components in addition to the antifouling coating and film-forming component which confer a desirable property, such as hardness, strength, rigidity, reduced drag, impermeability, or water resistance.
The present invention encompasses any article which contains a surface coated with a coating containing at least one of said lactone compounds. Those articles which are particularly suitable for protection with the coating are those which, either intentionally or inadvertently, are submerged for a least the duration required for an organism to settle on a submerged object. Coated articles can comprise any material to which aquatic organisms are know to attach, such as metal, wood, concrete, polymer, and stone. Exemplary articles which may require antifouling protection include boats and boat hulls, fish nets, recreational equipment, such as surfboards, jet skis, and water skis, piers and pilings, buoys, off-shore oil rigging equipment, decorative or functional stone formations, and the like.
The composition of the invention can be a cementitious composition which includes at least one of said antifouling compounds and a cementitious matrix. Such a composition is suitable for use in submerged structures, such as piers, pilings, and offshore oil rigging equipment and scaffolding, upon which fouling organisms tend to settle. Exemplary cementitious matrix compositions include portland cement and calcium aluminate based compositions. As those skilled in this art will appreciate, the cementitious matrix should be able to release the antifouling compound, and the antifouling compound must be present in sufficient concentration that the release rate of the compound into the surrounding aquatic environment inhibits settling of organisms on the submerged surface of an article formed from the composition.
The invention is now described in more detail in the following examples which are provided to more completely disclose the information to those skilled in this art, but should not be considered as limiting the invention.
EXAMPLES
Collection and Culture of Experimental Specimens
Adult individuals of the acorn barnacle Balanus amphitrite Darwin were collected from the Duke University Marine Laboratory seawall in Beaufort, N.C. Collected specimens were crushed, and the nauplius stage larvae released therefrom were cultured to cyprid stage for cyprid-stage assays according to the methods of Rittschof et al., J. Exp. Mar. Biol. Ecol. 82:131-146 (1984).
Settlement Assays for Cyprid-Stage Larvae
All compounds were tested for their ability to inhibit settlement by cyprid larvae of the barnacle Balanus amphitrite . Larvae were added to either polystyrene dishes or clean glass vials containing 5 ml of aged seawater that had passed through a 100 kDa cut-off filter and varying levels of test compound. Controls consisted of barnacle larvae and filtered seawater added to the dishes or vials without test compound. Dishes were then incubated for 20-24 hrs at 28° C. with light for approximately 15 hours and in darkness for approximately 9 hours. The dishes or vials were then removed from the incubator, examined under a dissecting microscope to determine whether larvae were living or dead. Larvae were then killed by addition of several drops of 10% formalin solution. Settlement rate was quantified as number of larvae that had attached to the dish or vial surface, expressed as a percentage of total larvae in the dish or vial. Experiments were performed in duplicate. The lower the percent settlement, the more efficacious the test compound.
EXAMPLE 1
A number of lactones were tested for control of barnacle settlement. All lactones were tested at a concentration of 3×10 -6 M in dishes containing seawater. The larvae were added and the test conducted as described above. These data are presented in Table 1.
TABLE 1______________________________________Control of Barnacle Settlement with LactonesCompound % Settlement______________________________________Control 35γ-undecalactone 0δ-undecalactone 40ε-caprolactone 41δ-dodecanolactone 38γ-octanolactone 39γ-decalactone 3γ-valerolactone 26______________________________________
EXAMPLE 2
Solutions of α-methylene-γ-butyrolactone were prepared in seawater at the concentrations shown in the table below. Five ml of each solution were added to duplicate dishes. The larvae were then added to the dishes and the test conducted as described above. These data are presented in Table 2.
TABLE 2______________________________________Control of Barnacle Settlementwith α-Methylene-γ-butyrolactoneConcentration % Settlement______________________________________0 (Control) 62500 μg/ml 050 μg/ml 05 μg/ml 36500 ng/ml 5850 ng/ml 625 ng/ml 61______________________________________
EXAMPLE 3
A second test was performed with α-methylene-γ-butyrolactone. A series of solutions of α-methylene-γ-butyrolactone in seawater at concentrations ranging from 500 μg/ml to 50 ng/ml were prepared. Aliquots of these solutions were taken and added to duplicate dishes. The actual concentrations tested appear in the table below. The larvae were then added to the dishes and the test conducted as described above. These data are presented in Table 3.
TABLE 3______________________________________Control of Barnacle Settlementwith α-Methylene-γ-butyrolactoneConcentration % Settlement______________________________________0 (Control) 66500 μg/ml 550 μg/ml 295 μg/ml 47500 ng/ml 5350 ng/ml 49______________________________________
EXAMPLE 4
Solutions of α-angelica lactone were prepared in seawater at the concentrations shown in the table below. Five ml of each solution were added to duplicate dishes. The larvae were then added to the dishes and the test conducted as described above. These data are presented in Table 4.
TABLE 4______________________________________Control of Barnacle Settlement with α-Angelica lactoneConcentration % Settlement______________________________________0 (Control) 62500 μg/ml 050 μg/ml 395 μg/ml 54500 ng/ml 6050 ng/ml 655 ng/ml 62______________________________________
EXAMPLE 5
A second test was performed with α-angelica lactone. A series of solutions of a-angelica lactone in seawater at concentrations ranging from 500 μg/ml to 5 ng/ml were prepared. Aliquots of these solutions were taken and added to duplicate dishes. The actual concentrations tested appear in the table below. The larvae were then added to the dishes and the test conducted as described above. These data are presented in Table 5.
TABLE 5______________________________________Control of Barnacle Settlement with α-Angelica lactoneConcentration % Settlement______________________________________0 (Control) 66500 μg/ml 050 μg/ml 35 μg/ml 33500 ng/ml 3350 ng/ml 535 ng/ml 41______________________________________
EXAMPLE 6
A solution of 2-coumaranone (25 μg in 50 ml of filtered, aged seawater) was prepared. Aliquots of this solution were taken and added to duplicate dishes to provide the nominal concentrations shown in the table below. The larvae were then added to the dishes and the test conducted as described above. These data are presented in Table 6.
TABLE 6______________________________________Control of Barnacle Settlement with 2-CoumaranoneConcentration % Settlement______________________________________0 (Control) 58500 μg/ml 050 μg/ml 645 μg/ml 51500 ng/ml 5950 ng/ml 615 ng/ml 54______________________________________
EXAMPLE 7
A series of solutions of γ-decalactone in seawater at concentrations ranging from 500 μg/ml to 5 pg/ml were prepared. Aliquots of these solutions were taken and added to duplicate dishes. The actual concentrations tested appear in the table below. The larvae were then added to the dishes and the test conducted as described above. These data are presented in Table 7.
TABLE 7______________________________________Control of Barnacle Settlement with γ-DecalactoneConcentration % Settlement______________________________________0 (Control) 66500 μg/ml 050 μg/ml 15 μg/ml 25500 ng/ml 850 ng/ml 255 ng/ml 32500 pg/ml 4450 pg/ml 525 pg/ml 45______________________________________
EXAMPLE 8
A series of solutions of γ-valerolactone in seawater at concentrations ranging from 500 μg/ml to 500 pg/ml were prepared. Aliquots of these solutions were taken and added to duplicate dishes. The actual concentrations tested appear in the table below. The larvae were then added to the dishes and the test conducted as described above. These data are presented in Table 8.
TABLE 8______________________________________Control of Barnacle Settlement with γ-ValerolactoneConcentration % Settlement______________________________________0 (Control) 66500 μg/ml 5250 μg/ml 375 μg/ml 42500 ng/ml 4850 ng/ml 425 ng/ml 43500 pg/ml 55______________________________________
EXAMPLE 9
Toxicity assays were conducted by adding nauplius stage larvae to 50×5 mm polystyrene Petri dishes or glass vials containing 5 ml of 100 kDa iltered seawater. Experimental dishes received doses of γ-decalactone, α-angelica lactone, α-methylene-γ-butyrolactone, α-santonin and alantolactone. Dishes or vials receiving no test compound served as controls. The dishes or vials were incubated at 28° C. with a 15:9 light:dark cycle. After incubation, the dishes or vials were examined under a dissecting microscope to determine whether the larvae were alive or dead. Larvae which did not respond to an emission of visible light were considered dead. The number of living and dead larvae were then counted. Probit analysis was used to obtain concentrations corresponding to half-maximal inhibition (EC 50 values). These data are summarized in Table 9.
TABLE 9______________________________________Lactone Half-maximal Inhibition ValuesCompound ED.sub.50______________________________________γ-decalactone 4 ng/ml (plastic)α-angelica lactone 70 μg/ml (plastic)α-methylene-γ-butyrolactone 6 μg/ml (plastic)α-methylene-γ-butyrolactone 40 μg/ml (glass)α-santonin 14 μg/ml (glass)alantolactone 500 ng/ml (glass)______________________________________
While the invention has been described with reference to specific examples and applications, other modifications and uses for the invention will be apparent to those skilled in the art without departing from the spirit and scope of the invention as defined in the following claims. | Certain gamma lactones are disclosed as being useful as marine or fresh water antifoulant compounds to be used in protective carrier compositions such as film forming polymer to protect fish nets, boats, pilings, and piers. | 8 |
This invention was made with Government support under contract number N66001-04-C-8032 awarded by the Defense Advanced Research Projects Agency (DARPA). The government has certain rights in this invention.
RELATED APPLICATIONS
This Application is related to application Ser. No. 11/853,139 filed on Sep. 11, 2007. This Application is related to application Ser. No. 12/540,457 filed on Aug. 13, 2009.
FILED OF THE INVENTION
The present invention relates to the field of integrated circuits; more specifically, it relates to structures of and methods for fabricating ultra-deep vias in integrated circuits and structures of and methods for fabricating three-dimensional integrated circuits.
BACKGROUND OF THE INVENTION
In order to reduce the footprint and improve the speed of integrated circuits various three-dimensional integrated circuit structures have been proposed. Traditional integrated circuit structures have been two dimensional, in that all the active devices have been formed in a same plane in a same semiconductor layer. Three-dimensional integrated circuits utilize vertically stacked semiconductor layers with active devices formed in each of the stacked semiconductor layers.
The fabrication of three-dimensional integrated circuits poses many challenges particularly in the methodology for interconnecting devices in the different semiconductor layers together. The total depth of these interconnects can exceed 1.5 um with diameters in the sub 0.2 um range. It is difficult to fill vias having such large depth to width aspect ratios with high quality, defect free metal. In particular, the metal fill of large aspect ratio and very deep vias often contain voids which can increase the resistance of the via and result in yield loss as well as reduce the reliability of the device. Accordingly, there exists a need in the art to overcome the deficiencies and limitations described hereinabove.
SUMMARY OF THE INVENTION
A first aspect of the present invention is structure, comprising: a substrate; a first dielectric layer on a top surface of the substrate; a second dielectric layer on a top surface of the first dielectric layer; a third dielectric layer on a top surface of the second dielectric layer; a fourth dielectric layer on a top surface of the third dielectric layer; an opening extending from a top surface of the fourth dielectric layer to the top surface of the substrate; a first width of the opening measured in first direction parallel to the top surface of the fourth dielectric layer at the top surface of the fourth dielectric layer is greater than a second width of the opening measured in the first direction at the top surface of the third dielectric layer and greater than a third width of the opening measured in the first direction at a top surface of the substrate, the second width greater than or equal to the third width; a ratio of a depth of the opening measured in a second direction perpendicular to the first direction from the top surface of the fourth dielectric layer to the top surface of the substrate to the third width is equal to or greater than five; and an electrical conductor filling the opening.
A second aspect of the present invention is the first aspect, wherein: the first and third dielectric layers comprise silicon nitride; and the second and fourth dielectric layers comprise a silicon oxide.
A third aspect of the present invention is the first aspect, wherein: the first dielectric layer and the third dielectric layer each independently have respective thicknesses at least five times less than either a thickness of the second dielectric layer or a thickness of the fourth dielectric layer; and a total thickness of the first, second, third and fourth dielectric layers is greater than or equal to about 1 micron.
A fourth aspect of the present invention is the first aspect, further including: a first silicon layer embedded in the fourth dielectric layer, a first transistor in the first silicon layer, an electrically conductive contact in the fourth dielectric layer, the contact electrically contacting the first transistor; a first set of wiring levels on a top surface of fourth dielectric layer, a wire or wires in the first set of wiring levels electrically connecting the contact to the electrical conductor in the opening; and the substrate including a second set of wiring levels contacting a bottom surface of the first dielectric layer, a wire or wires in the second set of wiring levels electrically connecting the electrical conductor in the opening to a second transistor formed in a second silicon layer in contact with a bottom surface of the second set of wiring levels.
A fifth aspect of the present invention is the first aspect, wherein: the first and third dielectric layers independently comprise a material selected from the group consisting of low temperature oxide, high density plasma oxide, with plasma enhanced chemical vapor deposition oxide, ultrahigh density plasma oxide, tetraethoxysilane oxide, spin-on-oxide and layers thereof.
A sixth aspect of the present invention is the first aspect, wherein: the second and fourth dielectric layers independently comprise a material selected from the group consisting of silicon nitride, silicon carbide, silicon oxy nitride, silicon oxy carbide and Nblock (SiCNH).
A seventh aspect of the present invention is the first aspect, wherein the electrical conductor comprises: a tantalum nitride layer over sidewalls and a bottom of the opening; a tantalum layer on the tantalum nitride layer; a seed copper layer the tantalum layer; and an electroplated copper layer on the seed copper layer, the electroplated copper layer completely filling remaining spaces in the opening.
An eighth aspect of the present invention is the first aspect, wherein the third dielectric layer comprises multiple dielectric layers.
A ninth aspect of the present invention is the first aspect, wherein the third dielectric layers comprises fifth, sixth and seventh dielectric layers, the fifth dielectric layer in abutting the second dielectric layer, the sixth dielectric layer between the fifth and seventh dielectric layers.
A tenth aspect of the present invention is the ninth aspect, wherein: the fifth dielectric layer extends through regions of a silicon layer between a bottom surface of second dielectric layer and a top surface of the sixth dielectric layer.
An eleventh aspect of the present invention is a structure, comprising: a first substrate, the first substrate including: first transistors electrically connected to a set of wiring levels, each wiring level including electrically conductive wires in a respective dielectric layer; an etch stop layer on a top surface of an uppermost wiring level of the set of wiring levels that is furthest from the substrate, the etch stop layer in contact with a wire of the uppermost wiring level; a first dielectric bonding layer on a top surface of the etch stop layer; and a bottom surface of the first dielectric bonding layer in contact with a top surface of the etch stop layer; a second substrate, the second substrate including: a second dielectric bonding layer; a buried oxide layer on a top surface of the second dielectric bonding layer; a silicon layer on a top surface of the buried oxide layer, the silicon layer including second transistors electrically isolated from each other by dielectric isolation in the silicon layer; a profile modulation layer on a top of the silicon layer and on a top surface of the dielectric isolation; and a dielectric layer on a top surface of the profile modulation layer; a top surface of the first dielectric bonding layer bonded to a bottom surface of the buried oxide; an opening extending from the top surface of the dielectric layer, through the profile modulation layer, through the dielectric isolation, through the buried oxide layer through the first and second dielectric bonding layer and through the etch stop layer to a top surface of the wire; and an electrical conductor filling the opening, the electrical conductor in electrical contact with the wire.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the invention are set forth in the appended claims. The invention itself, however, will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIGS. 1A through 1J are cross-sections of the fabrication of an exemplary electrically conductive via according to embodiments of the present invention;
FIGS. 2A through 2C are cross-sections of the fabrication of a first exemplary three dimensional integrated circuit according to embodiments of the present invention; and
FIG. 3 is a cross-section of additional fabrication steps in the fabrication of three-dimensional integrated circuit according to embodiments of the present.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1A through 1J are cross-sections of the fabrication of an exemplary electrically conductive via according to embodiments of the present invention. In FIG. 1A , formed in a semiconductor substrate 100 is a metal wire 105 . Formed on a top surface 110 of substrate 100 is a dielectric etch stop layer 115 . Formed on top of etch stop layer 115 is a first dielectric layer 120 . Formed on first dielectric layer 120 is a second dielectric layer 125 . Formed on second dielectric layer 125 is a third dielectric layer 130 . Formed on top of third dielectric layer 130 is a profile modulation layer 135 . Formed on profile modulation layer 135 is a fourth dielectric layer 140 . Semiconductor substrate 100 may comprise, for example, Si, SiGe, Ge, GaAs or InP.
The stack of dielectric materials consisting of dielectric etch stop layer 115 , first dielectric layer 120 , second dielectric layer 125 , third dielectric layer 130 , profile modulation layer 135 and fourth dielectric layer 140 simulates a structure that conductive vias are formed through in fabrication of a three-dimensional integrated circuit according to embodiments of the present invention described infra. Therefore in one example, etch stop layer 115 and first dielectric layer 120 represent layers on a lower semiconductor substrate and second dielectric layer 125 , third dielectric layer 130 , profile modulation layer 135 and fourth dielectric layer 140 represent layers on an upper semiconductor layers with first and second dielectric layers 120 and 125 representing oxide bonding layers that bond the two substrates together. Third dielectric layer 130 represents a dielectric trench isolation (TI) or dielectric shallow trench isolation (STI) on a buried oxide layer (BOX) of a silicon-on-insulator (SOI) substrate.
In accordance with the simulation of a three-dimensional integrated circuit according to embodiments of the present invention, etch stop layer 115 is silicon nitride and in one example is about 500 Å thick, first dielectric layer 120 is low temperature silicon oxide (LTO) and in one example is between about 2500 Å and about 3500 Å thick, second dielectric layer 125 is LTO and in one example is between about 2500 Å and about 3500 Å thick, third dielectric layer 130 is high density plasma silicon (HDP) oxide thermal oxide and in one example is about 3600 Å thick, profile modulation layer 135 is silicon nitride and in one example is about 500 Å thick and fourth dielectric layer 140 is HDP oxide and in one example is about 4700 Å thick. In one example, metal wire 105 comprises copper. The HDP oxide of third dielectric layer 130 and fourth dielectric layer 140 may be independently replaced with plasma enhanced chemical vapor deposition (PECVD) oxide, ultrahigh density plasma (UHP) oxide, tetraethoxysilane (TEOS) oxide or spin-on-oxide. The silicon nitride of etch stop layer 115 and profile modulation layer 135 may be independently replaced with silicon carbide, silicon oxy nitride, silicon oxy carbide or Nblock (SiCNH). In oxide fusion bonding applications, first and second dielectric layer are LTO, but in other application may be independently thermal oxide, HDP oxide, PECVD oxide, UDP oxide, TEOS oxide or spin-on-oxide. In one example, thicknesses of etch stop layer 115 and profile modulation layer 135 are independently about 5 times less than a thickness of either fourth dielectric layer 140 or a combined thickness of first, second and third dielectric layers 120 , 125 and 130 .
An LTO oxide is a silicon oxide that is formed at temperatures below about 350° C. In one example, LTO oxides are formed using N 2 O in a plasma enhanced chemical vapor deposition (PECVD) process. An HDP oxide are specifically prepared to be fusion bonded to each other.
First second, third and fourth dielectric layers 120 , 125 , 130 and 140 are advantageously first similar materials (e.g., silicon oxides) and etch stop layer 115 and profile modulation layer 135 are advantageously second similar materials (e.g. silicon nitrides), where the second materials may be selectively plasma etched relative to the first materials.
In FIG. 1B , an optional antireflective coating (ARC) 145 is formed on fourth dielectric layer and a photoresist layer 150 formed on top of the ARC. An opening 155 is formed in photoresist layer 150 photolithographically by exposing photoresist layer 150 to actinic radiation through a patterned photomask and then developing the photoresist layer to transfer the pattern of the photomask into the photoresist layer. A region of ARC 145 is exposed in the bottom of opening 155 . ARC 145 is a bottom ARC or BARC since it is formed under photoresist layer 150 . A top ARC (TARC) formed over the photoresist may be substituted or both a TARC and BARC may be used. The combination of a photoresist layer and an ARC (i.e., BARC, TARC or both BARC and TARC) is defined as a photo-imaging layer.
In FIG. 1C , the region of ARC 145 exposed in opening 155 of FIG. 1B is removed using a reactive ion etch (RIE) that etches ARC 145 faster than photoresist layer 150 (i.e., ARC 145 is RIE'd selective to photoresist layer 150 ) to expose a region of fourth dielectric layer 140 in the bottom of an opening 155 A. An example RIE process for etching ARC 145 includes etching with a mixed CF 4 /CHF 3 /Ar/O 2 gas derived plasma.
In FIG. 1D , the region of fourth dielectric layer 140 exposed in opening 155 A of FIG. 1C is removed using an RIE that etches fourth dielectric layer 140 faster than profile modulation layer 135 (i.e., fourth dielectric layer 140 is RIE'd selective to profile modulation layer 135 ) to expose a region of the profile modulation layer in the bottom of an opening 155 B. Note, photoresist layer 150 and ARC 145 are eroded by the fourth dielectric layer 140 RIE etch. The opening in the top surface of photoresist layer 150 is larger than the opening in the bottom surface of the photoresist layer. An example RIE process for etching fourth dielectric layer includes etching with a mixed CO/C 4 F 8 /Ar gas derived plasma. This chemistry (at the proper bias, forward and reverse power, pressure and gas flows) etches silicon oxide about 25 times faster than silicon nitride.
In FIG. 1E , the region of profile modulation layer 135 exposed in opening 155 B of FIG. 1D is removed using an RIE that etches profile modulation layer 135 faster than third dielectric layer 130 (i.e., profile modulation layer 135 is RIE'd selective to third dielectric layer 130 ) to expose a region of the third dielectric layer in the bottom of an opening 155 C. An example RIE process for etching profile modulation layer includes etching with a mixed CHF 3 /CF 4 /Ar gas derived plasma. This chemistry (at the proper bias, forward and reverse power, pressure and gas flows) etches silicon nitride about 4 times faster than silicon oxide. It is advantageous to keep profile modulation layer 135 (and etch stop layer 115 ) as thin as possible.
In FIG. 1F , the region of third dielectric layer 130 exposed in opening 155 C of FIG. 1E is removed along with regions of second and first dielectric layers 125 and 120 aligned under opening 155 C of FIG. 1E using an RIE that etches third, second and first dielectric layers 130 , 125 and 120 faster than etch stop layer 115 and profile modulation layer 135 (i.e., third dielectric layer 130 is RIE'd selective to etch stop layer 115 and profile modulation layer 135 ) to expose a region of the etch stop layer in the bottom of an opening 155 D. An example RIE process for etching third, second and first dielectric layers 130 , 125 and 120 includes etching with a mixed CO/C 4 F 8 /Ar gas derived plasma. Note, photoresist layer 150 and ARC 145 are further eroded by the third dielectric layer 130 , second dielectric layer 125 and first dielectric 120 RIE etches. This etch is not selective to fourth dielectric layer 140 and in combination with the further erosion of photoresist layer 150 and ARC 145 , a tapered upper region 160 of opening 155 D is formed in the region of opening 155 D formed through fourth dielectric layer 140 . The sidewall of opening 155 D in region 160 taper at an angle “a” measured between the sidewall and a plane parallel to top surface 110 of substrate 100 . A lower region 165 of opening 155 D is formed through profile modulation layer 135 and third, second and first dielectric layers 130 , 125 and 120 . The sidewall of opening 155 D in region 165 is at an angle “b” measured between the sidewall and a plane parallel to top surface 110 of substrate 100 . Opening 155 D has width W 1 measured at the top surface of fourth dielectric layer 140 , a width W 2 measured at a top surface of profile modulation layer 135 and a width W 3 , measured at a top surface of etch stop layer 115 . W 1 is greater than W 2 . In one example W 1 is about 0.28 microns and W 3 is about 0.16 microns.
In one example, W 2 is equal to W 3 and angle “b” is between about 87° and no greater than 90°. In one example W 2 is greater than W 3 , however angle “b” is less than angle “a.” Again, the presence of profile modulation layer 135 allows the widening of opening 155 D at the top surface of fourth dielectric layer 140 in upper region 160 due to the controlled erosion of photoresist layer 150 while facilitating formation of a straight or sidewall in lower region 165 . Without profile modulation layer 135 , either opening 155 D would be to narrow at the top to be filled with metal without incorporating large voids in the metal fill, or the value of W 1 would need to be much greater to maintain the same value of W 3 obtained with the presence of the profile modulation layer.
In FIG. 1G , photoresist layer 150 and arc 145 (See FIG. 1F ) are removed using an oxygen ash process (i.e., O 2 plasma etch). Alternatively, this step may be performed after the process illustrated in FIG. 1H . It is advantageous to perform the photoresist removal step with etch stop layer 115 intact to prevent the photoresist removal process from oxidizing wire 105 particularly when wire 105 comprises copper.
In FIG. 1H , the region of etch stop layer 115 exposed in opening 155 D of FIG. 1G is removed using an RIE that etches stop layer 115 faster than first, second, third dielectric layers 120 , 125 and 130 (i.e., etch stop layer 115 is RIE'd selective to first, second and third dielectric layers 120 , 125 and 130 , metal wire 105 and optionally fourth dielectric layer 140 ) to expose a region of metal wire 105 in the bottom of an opening 155 E. An example RIE process for etching etch stop layer 115 includes etching with a mixed CF 4 /CHF 3 /Ar/O 2 gas derived plasma. Region 160 has a height H 1 measured from the top surface of fourth dielectric layer 140 to the top surface of profile modulation layer 135 in a direction perpendicular to the top surface of wire 105 in substrate 100 . Region 165 has a height H 2 measured from the top surface of profile modulation layer 134 to the top surface of wire 105 in substrate 100 in a direction perpendicular to the top surface of wire 105 in substrate 100 . In one example H 1 is about 0.4 microns and H 2 is between about 1 micron an and about 1.6 microns for total opening depth (i.e., H 1 +H 2 ) of between about 1.4 microns and about 2.0 microns. With a value of W 3 (see FIG. 1F ) of about 0.16 microns the depth to width ratio of opening 155 E is between about 1.4/0.16 about 8.75 and about 2.0/0.16=about 12.5. In one example, H 1 +H 2 is equal to or greater than about 1 micron. In one example, H 1 +H 2 is equal to or greater than about 2 microns. In one example (H 1 +H 2 )/W 1 is greater than or equal to 5. In one example (H 1 +H 2 )/W 1 is greater than or equal to 8.
In FIG. 1I , an optional direct current (DC) clean (e.g., sputter cleaning with an inert gas) is performed followed by formation of an electrically conductive liner 170 on the sidewall of opening 155 E and top surface of fourth dielectric layer 140 followed by overfilling the opening 155 E with an electrically conductive core conductor 175 . In one example, conductive liner 170 comprises, in the order of deposition, a layer of TaN, a layer of Ta and a layer of Cu and core conductor 175 comprises electroplated copper.
In FIG. 1J , a chemical-mechanical-polish (CMP) is performed to remove liner 170 and core conductor 175 from over fourth dielectric layer 140 to form an electrically conductive via 180 extending from a top surface 185 of the fourth dielectric layer to a top surface of wire 105 (making electrical contact with wire 105 ). After the CMP, a top surface 190 of via 180 is coplanar with top surface 185 of fourth dielectric layer 140 .
It should be understood in the simplest form, embodiments of the present invention may be practiced on a dielectric stack where first, second and third dielectric layers 120 , 125 and 130 of FIG. 1 are replaced with a single dielectric layer. In other embodiments, their may be more than three dielectric layers in the stack represented by first, second and third dielectric layers 120 , 125 and 130 of FIG. 1 , though they should all be similar materials (e.g., silicon oxides) or have similar selectivity's to the RIE used to etch stop and profile modulation layers.
FIGS. 2A through 2C are cross-sections of the fabrication of a first exemplary three-dimensional integrated circuit according to embodiments of the present invention. In FIG. 2A , an upper semiconductor substrate 200 includes a silicon oxide bonding layer 205 , a BOX layer 210 on the bonding layer, a semiconductor layer 215 including semiconductor regions 220 and STI 225 formed in the semiconductor layer, a profile modulation layer 230 on top of semiconductor layer 215 and a dielectric layer 235 on the passivation layer. Exemplary, field effect transistors (FETs) 240 comprising source/drains (S/D) formed in semiconductor regions 220 and gates formed over the silicon regions between the S/Ds are formed in substrate 200 . Semiconductor layer 215 may comprise, for example, Si, SiGe, Ge, GaAs or InP.
Etch stop layer may also serve as a diffusion barrier layer for copper and/or as a passivation layer.
A substrate 300 includes a semiconductor base later 305 , a BOX layer 310 on the base silicon layer, a semiconductor layer 315 including semiconductor regions 320 and STI 325 formed in the silicon layer, an interlevel dielectric (ILD) wiring set 330 including contacts 335 and wires 340 and 350 formed in respective dielectric layers of dielectric layers 355 of ILD wiring set 330 . Semiconductor base layer 305 may comprise, for example, Si, SiGe, Ge, GaAs or InP. Semiconductor layer 315 may comprise, for example, Si, SiGe, Ge, GaAs or InP.
An ILD wiring level comprises a dielectric layer and one or more wires, vias or contacts embedded therein. ILD wiring set 330 is illustrated having three ILD wiring levels. ILD wiring set 330 may include more or less ILD levels (down to one level containing contacts 335 ) or as many levels as required by the integrated circuit design. The ILD wiring levels of ILD wiring set 330 are, by way of example, damascene and dual-damascene ILD levels formed by damascene and dual-damascene processes.
A damascene process is one in which wire trenches or via openings are formed in a dielectric layer, an electrical conductor of sufficient thickness to fill the trenches is deposited on a top surface of the dielectric, and a chemical-mechanical-polish (CMP) process is performed to remove excess conductor and make the surface of the conductor co-planar with the surface of the dielectric layer to form damascene wires (or damascene vias). When only a trench and a wire (or a via opening and a via) is formed the process is called single-damascene.
A dual-damascene process is one in which via openings are formed through the entire thickness of a dielectric layer followed by formation of trenches part of the way through the dielectric layer in any given cross-sectional view. All via openings are intersected by integral wire trenches above and by a wire trench below, but not all trenches need intersect a via opening. An electrical conductor of sufficient thickness to fill the trenches and via opening is deposited on a top surface of the dielectric and a CMP process is performed to make the surface of the conductor in the trench co-planar with the surface the dielectric layer to form dual-damascene wires and dual-damascene wires having integral dual-damascene vias.
Returning to FIG. 2A , exemplary, field effect transistors (FETs) 345 comprising source/drains (S/D) formed in semiconductor regions 320 and gates formed over the silicon regions between the S/Ds are formed in substrate 300 . Contacts 335 and wires 340 electrically connect FETs 345 into circuits or portions of circuits. Substrate 300 further includes an etch stop layer 360 on top of ILD wiring set 355 and a silicon oxide bonding layer 365 on the etch stop layer. Bonding layers 205 and 365 bond substrates 200 and 300 into a single structure. The bonding process includes placing the bonding layers 205 and 365 in contact at a temperature above room temperature but below, for example, 350° C.
In one example, dielectric layers 235 , 355 and STI 225 are independently selected from the group consisting of thermal oxide, HDP oxide, PECVD oxide, UDP oxide, TEOS oxide and spin-on-oxide, and bonding layers 205 and 365 are LTO. In one example profile modulation layer 230 and etch stop layer 360 are independently selected from the group consisting of silicon nitride, silicon carbide, silicon oxy nitride or silicon oxy carbide. In a second example, dielectric layers 235 , 355 and STI 225 and bonding layers 205 and 365 are advantageously first similar materials (e.g., silicon oxides) and etch stop layer 360 and profile modulation layer 230 are advantageously second similar materials (e.g. silicon nitrides), where the first and second materials may be selectively plasma etched relative to each other. In one example, dielectric layer 235 is between about 2500 Å and about 7500 Å thick. In one example, profile modulation layer 230 is between about 250 Å and about 1000 Å thick. In one example, STI 225 is between about 1500 Å and about 2500 Å thick. In one example, BOX layer 210 is between about 1500 Å and about 2500 Å thick. In one example, bonding layer 210 is between about 2500 Å and about 3500 Å thick. In one example, bonding layer 365 is between about 2500 Å and about 3500 Å thick. In one example, etch stop layer 360 is between about 2500 Å and about 1000 Å thick.
Substrate 200 may be formed from an SOI substrate by removal of the semiconductor (e.g., silicon) base layer under BOX layer 210 after formation of FETs 240 followed by a deposition of a layer of LTO to form bonding layer 205 on BOX layer 225 . Substrate 300 may be formed from an SOI substrate complete with ILD wiring set 330 followed by deposition of etch stop layer 360 and a deposition of a layer of LTO to form bonding layer 365 .
In FIG. 2A , a photoresist layer 400 is formed on dielectric layer and patterned to form an opening 405 in the photoresist layer in a manner similar to that described supra for opening 155 in photoresist 150 of FIG. 1B . While no ARC (TARC or BARC) is illustrated in FIG. 2A , an ARC (TARC and/or BARC) may be used.
In FIG. 2B , an opening 410 is formed through dielectric layer 235 , profile modulation layer 230 , STI layer 225 , BOX layer 210 , bonding layers 205 and 365 and etch stop layer 360 to expose a top surface of wire 350 . Then photoresist layer 400 (see FIG. 2A ) is removed. The methodology is similar to that described supra with respect to the formation of opening 155 E of FIG. 1H . First dielectric layer 235 is RIE'd selective to profile modulation layer 230 using for example, a mixed CO/C 4 F 8 /Ar gas derived plasma when dielectric layer 235 is silicon oxide and profile modulation layer 230 is silicon nitride. This chemistry (at the proper bias, forward and reverse power, pressure and gas flows) etches silicon oxide about 25 times faster than silicon nitride. Second, profile modulation layer 230 is RIE'd selective to dielectric layer 235 and STI 225 , using, for example; a mixed CHF 3 /CF 4 /Ar gas derived plasma when dielectric layers 235 and STI 225 are silicon dioxide and profile modulation layer is silicon nitride. This chemistry (at the proper bias, forward and reverse power, pressure and gas flows) etches silicon nitride about 4 times faster than silicon oxide. It is advantageous to keep profile modulation layer 230 (and etch stop layer 360 ) as thin as possible. Third, STI 235 , BOX layer 210 , bonding layers 205 and 365 are RIE'd selective profile modulation layer 230 and etch stop layer 360 using, for example, a mixed CO/C 4 F 8 /Ar gas derived plasma when STI 235 , BOX layer 210 , bonding layers 205 and 365 are silicon oxide and profile passivation layer 230 and etch stop layer 360 are silicon nitride. The third RIE process is not selective to dielectric layer 235 so opening 410 has a tapered profile in dielectric layer 235 , a substantially straight or slightly tapered profile in STI 225 , BOX 210 , and bonding layers 205 and 365 (compared to the taper of opening 410 in dielectric layer 235 ) because of the presence of profile modulation layer 230 . Fourth, photoresist layer 400 (see FIG. 2A ) is removed using an oxygen ash process. Fifth, etch stop layer 360 is RIE'd selective to dielectric layer 235 . STI 225 , BOX layer 210 and bonding layers 205 and 365 using, for example, a mixed CF 4 /CHF 3 /Ar/O 2 gas derived plasma when etch stop layer 360 and profile modulation layer 230 are silicon nitride and dielectric layer 210 , STI 225 , BOX layer 225 and bonding layers 205 and 365 are silicon oxide. Sixth an optional DC clean using N 2 and H 2 (i.e. a mixed N 2 /H 2 gas derived plasma etch) is performed.
In FIG. 2C , opening 410 (see FIG. 2B ) is filled with an electrical conductor for an electrically conductive via 420 in electrical contact with wire 350 . In one example, via 420 is formed by deposition of an electrically conductive liner on the sidewall of opening 410 (see FIG. 2B ) and top surface of dielectric layer 235 followed by overfilling the opening with an electrically conductive core conductor. In one example, the conductive liner comprises, in the order of deposition, a layer of TaN, a layer of Ta and a layer of Cu and the core conductor comprises electroplated copper. After filling the opening a CMP is performed to remove the liner and core conductor from over dielectric layer 235 to form the via 420 extending from a top surface 425 of dielectric layer 235 to a top surface of wire 350 . After the CMP, a top surface 430 of via 420 is coplanar with top surface 425 of dielectric layer 235 . Thus via 420 is a damascene via.
Electrically conductive contacts (not shown) may be made through dielectric layer 235 to the S/Ds and gates of FETs 240 . Alternatively, the contacts may be formed prior to formation of photoresist layer 400 (see FIG. 2A ). Additional interlevel dielectric layer containing wires may be formed on top of dielectric layer 235 , the wires therein electrically connecting via 420 to FETs 240 and FETs 345 into circuits. See FIG. 34 .
FIG. 3 is a cross-section of additional fabrication steps in the fabrication of three-dimensional integrated circuit according to embodiments of the present. In FIG. 3 , an electrically conductive contact 440 is formed to one of FETs 240 and an ILD wiring set 445 is formed on dielectric layer 235 . ILD wiring level set 445 includes wires 450 and a terminal pad 455 . ILD wiring set 445 is illustrated having two ILD wiring levels. ILD wiring level set 445 may include more or less ILD levels (down to one level containing wires/terminal pads 455 ) or as many levels as required by the integrated circuit design. The ILD wiring levels of ILD wiring set 445 are, by way of example, damascene and dual-damascene ILD levels formed by damascene and dual-damascene processes. Contact 440 is illustrated as a damascene contact. One wire 450 connects contact 440 to contact 420 . Thus a three-dimensional integrated circuit is formed comprising FETs 240 and FETs 345 . It should be understood that ILD wiring level set may be formed over dielectric layer 235 of FIG. 2C to generate a structure similar to that illustrated in FIG. 3 , but where the upper substrate is a bulk silicon substrate instead of an SOI substrate.
In both the examples of FIGS. 2A through 2C and 3 , silicon layer 215 and BOX 210 is an SOI substrate and silicon layer 315 and BOX is an SOI substrate. It should be understood that substrate 300 may be replaced with a bulk silicon substrate.
Thus the embodiments provide a process methodology for deep vias and semiconductor devices using deep via structures that have profiles that are less susceptible to metal fill problems.
The description of the embodiments of the present invention is given above for the understanding of the present invention. It will be understood that the invention is not limited to the particular embodiments described herein, but is capable of various modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, it is intended that the following claims cover all such modifications and changes as fall within the true spirit and scope of the invention. | A method of forming a high aspect ratio via opening through multiple dielectric layers, a high aspect ratio electrically conductive via, methods of forming three-dimension integrated circuits, and three-dimensional integrated circuits. The methods include forming a stack of at least four dielectric layers and etching the first and third dielectric layers with processes selective to the second and fourth dielectric layers, etching the second and third dielectric layers with processes selective to the first and second dielectric layers. Advantageously the process used to etch the third dielectric layer is not substantially selective to the first dielectric layer. | 7 |
BACKGROUND OF THE INVENTION
Coatings having a high refractive index (n) are known from various applications, for example, optical lenses, antireflection coatings, planar waveguides or holographically writeable films. Coatings having high refractive indices can in principle be produced by various methods. By a purely physical route, metal oxides having a high refractive index, such as, for example, TiO 2 , Ta 2 O 5 , CeO 2 , Y 2 O 3 , are deposited in a high vacuum via plasma methods in the so-called “sputter process.” While refractive indices of more than 2.0 in the visible wavelength range can be achieved thereby without problems, the process is relatively complicated and expensive.
EP 0964019 A1 and WO 2004/009659 A1, for example, disclose organic polymers, for example, sulfur-containing polymers or halogenated acrylates (tetrabromophenyl acrylate, Polyscience Inc.), which inherently have a higher refractive index than conventional polymers and which can be applied to surfaces by simple methods from organic solutions according to conventional coating processes. However, the refractive indices are generally limited here to values up to about 1.7, measured in the visible wavelength range.
A further process variant which is becoming increasingly important is based on metal oxide nanoparticles, which are incorporated into organic or polymeric binder systems. The corresponding nanoparticle-polymer hybrid formulations can be applied to various substrates in a simple and economical manner, for example by means of spin coating. The achievable refractive indices are usually between the first-mentioned sputter surfaces and the layers of polymers having a high refractive index. With increasing nanoparticle contents, it is possible to achieve increasing refractive indices. For example, U.S. Pat. App. Pub. No. 2002/0176169 A1 discloses the preparation of nanoparticle-acrylate hybrid systems, the layers having a high refractive index containing a metal oxide, such as, for example, titanium oxide, indium oxide or tin oxide, and a UV-crosslinkable binder, for example based on acrylate, in an organic solvent. After spin coating, evaporation of the solvent and UV irradiation, corresponding coatings having a real part n of the refractive index of 1.60 to 1.95, measured in the visible wavelength range, can be obtained.
In addition to the physical properties, however, the processability and compatibility with other components are also important. Thus, organic materials which are obtained by photopolymerization, generally as homo- or copolymers of monomers having a high refractive index, play an important role, for example for the production of optical components, such as lenses, prisms and optical coatings (see, e.g., U.S. Pat. No. 5,916,987), or for the production of a contrast in holographic materials (see, e.g., U.S. Pat. No. 6,780,546). For such and similar applications, there is a need to be able to adjust the refractive index in a targeted manner and to vary it over ranges, for example by admixing components having a high refractive index.
For the abovementioned fields of use, polymers of olefinically unsaturated compounds, such as, preferably, (meth)acrylates, are typically used. In order to achieve a refractive index of 1.5 or higher, halogen-substituted aromatic (meth)acrylates or special alkyl methacrylates described in U.S. Pat. No. 6,794,471 can be used. Owing to their complicated preparation, the latter in particular are disadvantageous.
The suitability of substituted phenyl isocyanate-based urethane acrylates for the preparation of corresponding polymers has been described by Bowman (Polymer 2005, 46, 4735-4742).
The unpublished International Application PCT/EP2008/002464 discloses (meth)acrylates having a refractive index at λ=532 nm of at least 1.5, which are suitable for the production of optical data media, in particular those for holographic storage methods, and are based on industrially available raw materials. In this context, phenyl isocyanate-based compounds are also known, these always being based on unsubstituted phenyl rings on the isocyanate side.
In photopolymer formulations, acrylates having a high refractive index play a decisive role as a contrast-imparting component (U.S. Pat. No. 6,780,546). The interference field of signal and reference lightbeam (two planar waves in the simplest case) is mapped into a refractive index grating, which contains all information of the signal (the hologram), by the local photopolymerization at locations of high intensity in the interference field by the acrylates having a high refractive index. By illuminating the hologram only with the reference lightbeam, the signal can then be reconstructed. The strength of the signal thus reconstructed in relation to the strength of the incident reference light is referred to as diffraction efficiency, or DE below. In the simplest case of a hologram which is formed by the superposition of two planar waves, the DE is obtained from the quotient of the intensity of the light diffracted on reconstruction and the sum of the intensities of incident reference light and diffracted light. The higher the DE, the more efficient is a hologram with respect to the necessary quantity of reference light which is necessary in order to visualize the signal with a fixed brightness. Acrylates having a high refractive index are capable of producing refractive index gratings having a high amplitude between regions with the lowest refractive index and regions with the highest refractive index and thereby of permitting holograms having a high DE in photopolymer formulations
BRIEF SUMMARY OF THE INVENTION
The present invention relates, in general, to novel specially substituted phenyl isocyanate-based urethane acrylates having a high refractive index and to a process for the preparation thereof and the use thereof.
It has been surprisingly found that special substituted phenyl isocyanate-based urethane acrylates can be cured to give coatings and moldings having particularly high refractive indices in combination with improved DE values and are therefore particularly suitable as starting material for the production of materials having a high refractive index, in particular optical lenses, antireflection coatings, planar waveguides or holographically writeable materials.
The present invention therefore relates to urethane acrylates of the general Formula (I)
in which R 1 , R 2 , R 3 , R 4 , R 5 , in each case by themselves, may be a hydrogen or halogen atom or a (C 1 -C 6 )-alkyl, trifluoromethyl, (C 1 -C 6 )-alkylthio, (C 1 -C 6 )-alkylseleno, (C 1 -C 6 )-alkyltelluro or nitro group, with the proviso that at least one substituent of the group R 1 , R 2 , R 3 , R 4 , R 5 is not hydrogen R 6 , R 7 , in each case by themselves, may be hydrogen or a (C 1 -C 6 )-alkyl group and A is a saturated or unsaturated or linear or branched (C 1 -C 6 )-alkyl radical or a polyethylene oxide (m=2-6) or polypropylene oxide (m=2-6) radical, the corresponding salts, solvates or solvates of the salts of the compounds according to Formula (I) also being included.
One embodiment of the present invention includes a urethane acrylate of the general Formula (I), a corresponding salt, a solvate or a solvate of a salt thereof:
wherein R 1 , R 2 , R 3 , R 4 and R 5 each independently represent a substituent selected from the group consisting of hydrogen, halogens, C 1-6 -alkyls, trifluoromethyl, C 1-6 -alkylthios, C 1-6 -alkylselenos, C 1-6 -alkyltelluros, and nitro groups, with the proviso that at least one of R 1 , R 2 , R 3 , R 4 and R 5 is not hydrogen; R 6 and R 7 each independently represent a substituent selected from the group consisting of hydrogen and C 1-6 -alkyls; and A represents a saturated or unsaturated or linear or branched C 1-6 -alkyl radical or a polyalkylene oxide radical having 2-6 ethylene oxide or propylene oxide units.
Another embodiment of the present invention includes layers, layered structures and/or moldings comprising a urethane acrylate according to the various embodiments of the invention.
Yet another embodiment of the invention includes articles such as, for example, optical lenses, mirrors, deflection mirrors, filters, diffusion screens, diffraction elements, waveguides, light guides, projection screens, masks, personal portraits, biometric presentations in security documents, images, image structures and combinations thereof which comprise a layer or molding according to the present invention.
Preferred radicals R 1 to R 5 are (C 1 -C 6 )-alkylthio substituents or chlorine or bromine, and methylthio substituents or chlorine or bromine are particularly preferred. In a particularly preferred embodiment, at least one substituent of the group R 1 , R 2 , R 3 , R 4 and R 5 is a (C 1 -C 6 )-alkylthio substituent or chlorine or bromine and the other substituents of the group R 1 , R 2 , R 3 , R 4 and R 5 are hydrogen atoms. Preferred radicals R 6 and R 7 are hydrogen atoms. The radical A is preferably a linear C 2 -C 4 or branched C 3 -alkyl radical, particularly preferably a linear C 2 — or C 4 -alkyl radical.
The urethane acrylates of the present invention are obtainable by reacting isocyanates of the Formula (II)
with isocyanate-reactive compounds of the Formula (III)
the radicals having the abovementioned meaning.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The foregoing summary, as well as the following detailed description of the invention, may be better understood when read in conjunction with the appended drawings. For the purpose of assisting in the explanation of the invention, there are shown in the drawings representative embodiments which are considered illustrative. It should be understood, however, that the invention is not limited in any manner to the precise arrangements and instrumentalities shown.
In the drawings:
FIG. 1 is schematic representation of a holographic measuring arrangement used in the Examples described herein.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the singular terms “a” and “the” are synonymous and used interchangeably with “one or more” and “at least one,” unless the language and/or context clearly indicates otherwise. Accordingly, for example, reference to “a urethane acrylate” herein or in the appended claims can refer to a single urethane acrylate or more than one urethane acrylate. Additionally, all numerical values, unless otherwise specifically noted, are understood to be modified by the word “about.”
Examples of compounds of the Formula (IS) are 2-thiomethylphenyl isocyanate, 3-thiomethylphenyl isocyanate, 4-thiomethylphenyl isocyanate, 2-chlorophenyl isocyanate, 3-chlorophenyl isocyanate, 4-chlorophenyl isocyanate, 2-bromophenyl isocyanate, 3-bromophenylisocyanate, 4-bromophenyl isocyanate, 2-iodophenyl isocyanate, 3-iodophenyl isocyanate, 4-iodophenyl isocyanate or mixtures thereof.
2-thiomethylphenyl isocyanate, 3-thiomethylphenyl isocyanate, 4-thiomethylphenyl isocyanate, 2-chlorophenyl isocyanate, 3-chlorophenyl isocyanate, 4-chlorophenyl isocyanate, 2-bromophenyl isocyanate, 3-bromophenyl isocyanate, 4-bromophenyl isocyanate or mixtures thereof are preferred.
2-thiomethylphenyl isocyanate, 3-thiomethylphenyl isocyanate and 4-thiomethylphenyl isocyanate, 3-chlorophenyl isocyanate, 3-bromophenyl isocyanate or mixtures thereof are particularly preferred.
Compounds of the Formula (III) which may be used are, for example, 2-hydroxyethyl(meth)acrylate, polyethylene oxide mono(meth)acrylate, polypropylene oxide mono(meth)acrylates, polyalkylene oxide mono(meth)acrylates, 2-hydroxypropyl(meth)acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl(meth)acrylate, 3-hydroxy-2,2-dimethylpropyl(meth)acrylate, hydroxypropyl(meth)acrylate or mixtures thereof.
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, polypropylene oxide mono(meth)acrylates, polyethylene oxide mono(meth)acrylates or mixtures thereof are preferred.
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate and 4-hydroxybutyl acrylate or mixtures thereof are particularly preferred.
The reaction of compounds of the Formula (II) with compounds of the Formula (III) is a urethanization. The reaction of compounds of the Formula (II) with compounds of the Formula (III) can be effected with the aid of the catalysts known for accelerating isocyanate addition reactions, such as, for example, tertiary amines, tin, zinc, iron or bismuth compounds, in particular triethylamine, 1,4-diazabicyclo[2.2.2]octane, bismuth octanoate or dibutyltin dilaurate, which can be initially introduced concomitantly or metered in later. The urethane acrylates according to the invention have a content of less than 0.5% by weight, preferably less than 0.2% by weight, particularly preferably less than 0.1% by weight, based on the urethane acrylate, of isocyanate groups (M=42) or free residual monomers. Furthermore, the urethane acrylates according to the invention contain contents of less than 1% by weight, preferably less than 0.5% by weight and particularly preferably less than 0.2% by weight, based on the urethane acrylate, of unreacted component compounds of the Formula (III). In the preparation of the urethane acrylates according to the invention, the compounds of the Formula (II) and the compounds of the Formula (III) can be dissolved in an unreactive solvent, for example an aromatic or aliphatic hydrocarbon or an aromatic or aliphatic halogenated hydrocarbon, or a coating solvent, such as, for example, ethyl acetate or butyl acetate or acetone or butanone or an ether, such as tetrahydrofuran or tert-butyl methyl ether, or a dipolar aprotic solvent, such as dimethylsulphoxide or N-methylpyrrolidone or N-ethylpyrrolidone, and initially introduced or metered in in a manner familiar to a person skilled in the art. After the end of the reaction, the unreactive solvent is removed from the mixture under atmospheric pressure or under reduced pressure and the end point is determined by determining the solids content. The solids contents are typically in a range from 99.999 to 95.0% by weight, preferably from 99.998 to 98.0% by weight, based on the urethane acrylate.
The urethane acrylates according to the invention can furthermore be protected from undesired polymerization by the addition of stabilizers. Such stabilizers may be oxygen-containing gas, as well as chemical stabilizers as described, for example, in Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], 4th edition, volume XIV/1, Georg Thieme Verlag, Stuttgart 1961, page 433 et seq. The following may be mentioned as examples: sodium dithionite, sodium hydrogen sulphide, sulphur, hydrazine, phenylhydrazine, hydrazobenzene, N-phenyl-β-naphthylamine, N-phenylethanoldiamine, dinitrobenzene, picric acid, p-nitrosodimethylaniline, diphenylnitrosamine, phenols, such as para-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butyl-4-methylphenol, p-tert-butylpyrocatechol or 2,5-di-tert-amylhydroquinone, tetramethylthiuram disulphide, 2-mercaptobenzothiazole, dimethyldithiocarbamic acid sodium salt, phenothiazine, N-oxyl compounds, such as, for example, 2,2,6,6-tetramethylpiperidine N-oxide (TEMPO) or one of its derivatives. 2,6-di-tert-butyl-4-methylphenol and para-methoxyphenol and mixtures thereof are preferred. Such stabilizers are typically used in an amount of 0.001 to 1% by weight, preferably 0.01 to 0.5% by weight, based on the urethane acrylate to be stabilized.
Layers, layer structures and mouldings obtainable from the urethane acrylates of the Formula (I), according to the invention, typically have a refractive index of >1.50, preferably >1.55, particularly preferably >1.58, at 405 nm and therefore likewise form a subject of the invention.
Layers, layer structures and mouldings obtainable from formulations which contain the urethane acrylates of the Formula (I), according to the invention, furthermore typically have DE values, measured by means of two-beam interference in reflection arrangement, of >25%, preferably >30%, particularly preferably >40%, very particularly preferably >50%. The exact description of the method is contained in the example section of the application.
The urethane acrylates of the Formula (I), according to the invention, are therefore outstandingly suitable for the production of holographic media and holographic photopolymer films.
The invention therefore also relates to a process for exposing holographic media and holographic photopolymer films to light, in which the urethane acrylates according to the invention, which are present in a polymer matrix, are selectively polymerized by electromagnetic radiation.
After appropriate holographic exposure to light, such holographic media are suitable for the production of holographic optical elements which have, for example, the function of an optical lens, a mirror, a deflection mirror, a filter, a diffusion screen, a diffraction element, a waveguide, a light guide, a projection screen and/or a mask.
Moreover, holographic images or presentations can also be produced therewith, such as, for example, for personal portraits, biometric presentations in security documents, or generally of images or image structures for advertising, security labels, trademark protection, trademark branding, labels, design elements, decorations, illustrations, trading cards, images and the like and images which can represent digital data, inter alia also in combination with the products described above.
The invention will now be described in further detail with reference to the following non-limiting examples.
EXAMPLES
Unless noted otherwise, all percentage data are based on percent by weight.
The measurement of the refractive index was effected at a wavelength of 405 n. The refractive index n as a function of the wavelength of the samples were obtained from the transmission and reflection spectra. For this purpose, about 100-300 nm thick films of the samples were applied by spin coating to quartz glass substrates from dilute solution in butyl acetate. The transmission and reflection spectrum of this layer packet was measured with a spectrometer from STEAG ETA Optik, CD-Measurement System ETA-RT, and the layer thickness and the spectral curve of n were then adapted to the measured transmission and reflection spectra. This is effected using the internal software of the spectrometer and additionally requires the n data of the quartz glass substrate which were determined beforehand in a blank measurement.
Example 1
2-({[3-(Methylsulphanyl)phenyl]carbamoyl}oxy)ethyl prop-2-enoate
0.02 g of 2,6-di-tert-butyl-4-methylphenol, 0.01 g of Desmorapid Z, 11.7 g of 3-(methylthio)phenyl isocyanate were initially introduced into a 100 ml round-bottomed flask and heated to 60° C. Thereafter, 8.2 g of 2-hydroxyethyl acrylate were added dropwise and the mixture was kept farther at 60° C. until the isocyanate content had fallen below 0.1%. Cooling was then effected. The product was obtained as a light yellow liquid.
Example 2
2-({[3-(Methylsulphanyl)phenyl]carbamoyl}oxy)propyl prop-2-enoate
0.05 g of 2,6-di-tert-butyl-4-methylphenol, 0.02 g of Desmorapid Z, 26.8 g of 3-(methylthio)phenyl isocyanate in 50 g of ethyl acetate were initially introduced into a 250 ml round-bottomed flask and heated to 60° C. Thereafter 21.1 g of 2-hydroxypropyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Thereafter, the ethyl acetate was distilled off at 5 mbar and cooling was effected. The product was obtained as a light yellow liquid.
Example 3
2-({[3-(Methylsulphanyl)phenyl]carbamoyl}oxy)butyl prop-2-enoate
0.05 g of 2,6-di-tert-butyl-4-methylphenol, 0.02 g of Desmorapid Z, 26.7 g of 3-(methylthio)phenyl isocyanate were initially introduced into a 250 ml round-bottomed flask and heated to 60° C. Thereafter, 23.3 g of 2-hydroxybutyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Thereafter, the ethyl acetate was distilled offat 5 mbar and cooling was effected. The product was obtained as a crystalline solid.
Example 4
2-{2-[2-({[3-(Methylsulphanyl)phenyl]carbamoyl}oxy)ethoxy]ethoxyl}ethyl 2-methylprop-2-enoate
0.02 g of 2,6-di-tert-butyl-4-methylphenol, 0.01 g of Desmorapid Z, 8.6 g of 3-(methylthio)phenyl isocyanate were initially introduced into a 100 ml round-bottomed flask and heated to 60° C. Thereafter, 11.7 g of polyethylene glycol monomethacrylate (PEM3, from LAPORTE Performance Chemicals UK LTD) were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Cooling was then effected. The product was obtained as a light yellow liquid.
Example 5
19-{[3-(Methylsulphanyl)phenyl]amino}-19-oxo-3,6,9,12,15,18-hexaoxanonadec-1-yl prop-2-enoate
0.02 g of 2,6-di-tert-butyl-4-methylphenol, 0.01 g of Desmorapid Z, 6.4 g of 3-(methylthio)phenyl isocyanate were initially introduced into a 100 ml round-bottomed flask and heated to 60° C. Thereafter, 13.6 g of Bisomer™ PEA 6 (from Cognis Deutschland GmbH & Co KG) were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Cooling was then effected. The product was obtained as a light yellow liquid.
Example 6
2,5,8,11,14,17-Hexamethyl-19-{[3-(methylsulphanyl)phenyl]amino}-19-oxo-3,6,9,12,15,18-hexaoxanonadec-1-yl prop-2-enoate
0.02 g of 2,6-di-tert-butyl-4-methylphenol, 0.01 g of Desmorapid 7, 5.6 g of 3-(methylthio)phenyl isocyanate were initially introduced into a 100 ml round-bottomed flask and heated to 60° C. Thereafter, 14.3 g of Bisomer™ PPA 6 (from Cognis Deutschland GmbH & Co KG) were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Cooling was then effected. The product was obtained as a crystalline solid.
Example 7
2-({[2-(Methylsulphanyl)phenyl]carbamoyl}oxy)propyl prop-2-enoate
0.008 g of 2,6-di-tert-butyl-4-methylphenol, 0.004 g of Desmorapid Z, 4.8 g of 2-(methylthio)phenyl isocyanate in 8.5 g of ethyl acetate were initially introduced into a 50 ml round-bottomed flask and heated to 60° C. Thereafter, 3.7 g of 3-hydroxypropyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Thereafter, the ethyl acetate was distilled off at 5 mbar and cooling was effected. The product was obtained as a light yellow liquid.
Example 8
2-({[2-(Methylsulphanyl)phenyl]carbamoyl}oxy)butyl prop-2-enoate
0.008 g of 2,6-di-tert-butyl-4-methylphenol, 0.004 g of Desmorapid Z, 4.3 g of 2-(methylthio)phenyl isocyanate in 8.5 g ethyl acetate were initially introduced into a 50 ml round-bottomed flask and heated to 60° C. Thereafter, 4 g of 3-hydroxybutyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Thereafter, the ethyl acetate was distilled off at 5 mbar and cooling was effected. The product was obtained as a light yellow liquid.
Example 9
2-({[4-(Methylsulphanyl)phenyl]carbamoyl}oxy)ethyl prop-2-enoate
0.02 g of 2,6-di-tert-butyl-4-methylphenol, 0.01 g of Desmorapid Z, 4.7 g of 4-(methylthio)phenyl isocyanate in 25 g of ethyl acetate were initially introduced into a 100 ml round-bottomed flask and heated to 60° C. Thereafter, 4.1 g of 2-hydroxyethyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Thereafter, the ethyl acetate was distilled off at 5 mbar and cooling was effected. The product was obtained as a crystalline solid.
Example 10
2-({[4-(Methylsulphanyl)phenyl]carbamoyl}oxy)propyl prop-2-enoate
0.02 g of 2,6-di-tert-butyl-4-methylphenol, 0.01 g of Desmorapid Z, 14.0 g of 4-(methylthio)phenyl isocyanate in 25 g of ethyl acetate were initially introduced into a 100 ml round-bottomed flask and heated to 60° C. Thereafter, 11.0 g of 3-hydroxypropyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Thereafter, the ethyl acetate was distilled off at 5 mbar and cooling was effected. The product was obtained as a light yellow liquid.
Example 11
2-({[4-(Methylsulphanyl)phenyl]carbamoyl}oxy)butyl prop-2-enoate
0.02 g of 2,6-di-tert-butyl-4-methylphenol, 0.01 g of Desmorapid Z, 13.3 g of 4-(methylthio)phenyl isocyanate in 25 g of ethyl acetate were initially introduced into a 100 ml round-bottomed flask and heated to 60° C. Thereafter, 11.6 g of 3-hydroxybutyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Thereafter, the ethyl acetate was distilled off at 5 mbar and cooling was effected. The product was obtained as a crystalline solid.
Example 12
2-{[(3-Chlorophenyl)carbamoyl]oxy}ethyl prop-2-enoate
0.15 g of 2,6-di-tert-butyl-4-methylphenol, 0.075 g of Desmorapid Z, 85.3 g of 3-chlorophenyl isocyanate were initially introduced into a 500 ml round-bottomed flask and heated to 60° C. Thereafter, 65.5 g of 3-hydroxybutyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Cooling was then effected. The product was obtained as a crystalline solid.
Example 13
2-{[(3-Bromophenyl)carbamoyl]oxy}ethyl prop-2-enoate
0.015 g of 2,6-di-tert.-butyl4-methylphenol, 0.007 g of Desmorapid Z, 9.4 g of 3-bromophenyl isocyanate were initially introduced in a 20 ml sample bottle and heated to 60° C. Thereafter, 5.5 g of 3-hydroxybutyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Cooling was then effected. The product was obtained as a crystalline solid.
Comparative Example 1
2-[(Phenylcarbamoyl)oxy]ethyl prop-2-enoate
0.25 g of 2,6-di-tert-butyl-4-methylphenol, 0.12 g of Desmorapid Z, 126.4 g of phenyl isocyanate were initially introduced into a 500 ml round-bottomed flask and heated to 60° C. Thereafter, 123.3 g of 2-hydroxyethyl acrylate were added dropwise and the mixture was kept further at 60° C. until the isocyanate content had fallen below 0.1%. Cooling was then effected. The product was obtained as a crystalline solid (preparation described in DE 2329142).
TABLE 1
Characterization of examples 1-13 and of comparative example 1
Refractive
Double bond
index at λ =
density
Example
405 nm
eq/kg (SC)
1
1.626
3.55
2
1.614
3.23
3
1.609
3.23
4
1.600
2.61
5
1.536
1.93
6
1.532
1.71
7
1.588
3.38
8
1.591
3.23
9
1.620
3.55
10
1.614
3.38
11
n.b.
3.23
12
1.589
3.72
13
1.602
3.19
Comparative
1.591
4.26
example 1
For testing the optical properties, media were produced and subjected to optical measurements as described below:
Preparation of the Polyol Component:
0.18 g of tin octanoate, 374.8 g of ε-caprolactone and 374.8 g of a difunctional polytetrahydrofuran polyether polyol (equivalent weight 500 g/mol OH) were initially introduced into a 1 l flask and heated to 120° C. and kept at this temperature until the solids content (proportion of nonvolatile constituents) was 99.5% by weight or more. Thereafter, cooling was effected and the product was obtained as a waxy solid.
Medium 1:
5.927 g of the polyol component prepared as described above were mixed with 2.50 g of urethane acrylate from Example 1, 0.10 g of CGI 909 (experimental product from. Ciba Inc, Basle, Switzerland) and 0.010 g of new methylene blue at 60° C. and 3.50 g of N-ethylpyrilidone so that a clear solution was obtained. Thereafter, cooling to 30° C. was effected, 1.098 g of Desmodur® XP 2410 (experimental product of Bayer MaterialScience AG, Leverkusen, Germany, hexane diisocyanate-based polyisocyanate, proportion of iminooxadiazinedione at least 30%, NCO content: 23.5%) were added and mixing was effected again. Finally, 0.006 g of Fomrez UL 28 (urethanization catalyst, commercial product from Momentive Performance Chemicals, Wilton, Conn., USA) was added and mixing was effected again briefly. The liquid material obtained was then poured onto a glass plate and covered there with a second glass plate which was kept at a distance of 20 μm by spacers. This test specimen was first left for 30 minutes at room temperature and then cured for two hours at 50° C.
The media 2-5 were produced in an analogous manner from the examples mentioned in Table 1.
Comparative Medium:
5.927 g of the polyol component prepared as described above were mixed with 2.50 g of 2-[(phenylcarbamoyl)oxy]ethyl prop-2-enoate (comparative Example 1), 0.10 g of CGI 909 (experimental product of Ciba Inc., Basle, Switzerland) and 0.010 g of new methylene blue at 60° C. and 3.50 g of N-ethylpyrilidone so that a clear solution was obtained. Thereafter, cooling to 30° C. was effected, 1.098 g of Desmodur® XP 2410 (experimental product of Bayer MaterialScience AG, Leverkusen, Germany, hexane diisocyanate-based polyisocyanate, proportion of iminooxadiazinedione at least 30%, NCO content: 23.5%) were added and mixing was effected again. Finally, 0.006 g of Fomrez UL 28 (urethanization catalyst, commercial product of Momentive Performance Chemicals, Wilton, Conn., USA) was added and mixing was effected again briefly. The liquid material obtained was then poured onto a glass plate and covered there with a second glass plate which was kept at a distance of 20 μm by spacers. This test specimen was first left for 30 minutes at room temperature and then cured for two hours at 50° C.
Measurement of the Holographic Properties of the Media by Means of Two-Beam Interference in Reflection Arrangement:
The media produced as described were then tested with respect to their holographic properties by means of a measuring arrangement according to FIG. 1 , as follows:
The beam of an He—Ne laser (emission wavelengths 633 nm) was converted with the aid of the spatial filter (SF) and together with the collimation lens (CL) into a parallel homogeneous beam. The final cross sections of the signal and reference beam are determined by the iris diaphragms (I). The diameter of the iris diaphragm opening is 0.4 cm. The polarization-dependent beam splitters (PBS) split the laserbeam into two coherent identically polarized beams. The power of the reference beam was adjusted to 0.5 mW and the power of the signal beam to 0.65 mW via the λ/2 plates. The powers were determined with the semiconductor detectors (D) after removal of the sample. The angle of incidence (α) of the reference beam is 21.8° and the angle of incidence (β) of the signal beam is 41.8°. At the location of the sample (medium), the interference field of the two overlapping beams produced a grating of light and dark strips which are perpendicular to the angle bisector of the two beams incident on the sample (reflection hologram). The strip spacing in the medium is ˜225 nm (refractive index of the medium assumed to be ˜1.49).
Meaning of the Reference Numerals in FIG. 1 :
M=mirror, S=shutter, SF=spatial filter, CL=collimator lens, λ/2=λ/2 plate, PBS=polarization-sensitive beam splitter, D=detector, I=iris diaphragm, α=21.80°, β=41.8°.
Holograms were written into the medium in the following manner:
Both shutters (S) are opened for the exposure time t.
Thereafter, with shutters (S) closed, the medium was allowed a time of 5 minutes for the diffusion of the still unpolymerized writing monomers.
The holograms written were now read in the following manner. The shutter of the signal beam remained closed. The shutter of the reference beam was opened. The iris diaphragm of the reference beam was closed to a diameter of <1 mm. This ensured that the beam always lay completely in the hologram written beforehand for all angles (Ω) of rotation of the medium. The turntable now covered the angular range of Ω=0° to Ω=20° with an angular step width of 0.05° under computer control. At each angle Ω reached, the powers of the beam transmitted in the zero order were measured by means of the corresponding detector D and the powers of the beam diffracted in the first order were measured by means of the detector D. At each angle Ω reached, the diffraction efficiency was obtained as the quotient of:
Power in the detector of the diffracted beam/(power in the detector of the diffracted beam+power in the detector of the transmitted beam)
The maximum diffraction efficiency (DE) of the hologram, i.e. its peak value, was determined. For this purpose, it might be necessary to change the position of the detector of the diffracted beam in order to determine this maximum value.
For a formulation, this procedure was if necessary repeated several times for different exposure times t on different media in order to determine the average energy dose of the incident laser beam during writing of the hologram DE at which the saturation value is reached. The average energy dose E is obtained as follows from the powers of the two partial beams (0.50 mW and 0.67 mW), the exposure time t and the diameter of the iris diaphragm (0.4 cm):
E (mJ/cm 2 )=2·[(0.50 mW+0.67 mW)· t ( s )]/[π·0.4 2 cm 2 ]
The powers of the partial beams were adapted so that the same power density is achieved in the medium at the angles α and β used.
The following measured values for DE [%] were obtained at the dose E [mJ/cm 2 ]:
TABLE 2
Holographic evaluation of selected examples
Medium
Example
Dose [mJ/cm 2 ]
DE [%]
1
1
37
68
2
5
37
26
3
7
73
26
4
8
73
57
5
13
73
38
Comparative
Comparative
73
24
medium
example 1
The values found for the dynamic range (DE) show that the urethane acrylate used in the comparative medium is less suitable for use in holographic media, whereas the urethane acrylates in the media 1 to 5 are very suitable for the production of holographic media owing to the higher value for DE.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. | Urethane acrylates of the general Formula (I), corresponding salts, solvates or solvates of a salt thereof:
wherein R 1 , R 2 , R 3 , R 4 and R 5 each independently represent a substituent selected from the group consisting of hydrogen, halogens, C 1-6 -alkyls, trifluoromethyl, C 1-6 -alkylthios, C 1-6 -alkylselenos, C 1-6 -alkyltelluros, and nitro groups, with the proviso that at least one of R 1 , R 2 , R 3 , R 4 and R 5 is not hydrogen; R 6 and R 7 each independently represent a substituent selected from the group consisting of hydrogen and C 1-6 -alkyls; and A represents a saturated or unsaturated or linear or branched C 1-6 -alkyl radical or a polyalkylene oxide radical having 2-6 ethylene oxide or propylene oxide units; processes for producing and methods of using the same. | 2 |
BACKGROUND OF THE INVENTION
The invention relates to a method of recognizing speech pauses in a speech signal which may have noise signals superposed on them.
Methods of this type are, for example, the prerequisite for the suppression of noise signals when telephone calls are made from an environment with acoustic disturbances. During the speech pause characteristic parameters of the noise signal are measured and employed to filter the noise before transmission substantially completely from the signal to be transmitted, using adaptive filters.
DE-AS No. 24 55 477 and corresponding to UK Patent Specification No. 1 515 937, column 10 discloses an arrangement in analog technique for recognizing speech pauses, which is based on the following method. The speech signal is divided into sections of equal lengths and a voltage value is obtained for each section by means of rectification and by taking the mean value, which voltage value is proportional to the average sound volume of the section. Finally, by taking the mean value during several speech sections a further voltage value is determined, which is proportional to the average loudness of the conversation. By comparing these two mean values it is determined whether a section is associated with a speech pause or not.
In the method of pause recognition no account is inter alia taken of the fact that, for example, unvoiced speech parts result in an almost total power reduction in the speech signal and that the relevant speech sections may therefore erroneously be recognized as speech pauses. Such faulty decisions occur in the prior art method more frequently according as the extent to which noise signals are superposed on the speech signal is greater.
SUMMARY OF THE INVENTION
It is therefore an object of the invention, to provide a method of recognizing pauses in a disturbed speech signal, in which faulty decisions as defined above are avoided. In addition, it must be possible to realize the method with digital means and speech pause recognition must also be possible when the average noise power changes only slowly.
This object is accomplished by means of the steps described in claim 1. The sub-claims describe advantageous embodiments.
The invention will now be further described by way of example with reference to the accompanying Figures.
DESCRIPTION OF THE FIGURES
In these Figures:
FIG. 1 is a block diagram to explain the method according to the invention.
FIGS. 2, 3 and 4 are diagrams to explain the method according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the block diagram shown in FIG. 1 sample values x(k), where k represents a natural number and 1/T o represents the sampling frequency, are obtained at sampling instants kT o by means of an analog-to-digital converter A/D from a disturbed speech signal applied to a terminal E. At all clock instants T(n) which are spaced apart in the time by mT o the mean value producer M produces a so-called short-time mean value from the amounts of m consecutive sampling values. ##EQU1##
The arithmetic mean from the amounts of the sampling values is used by way of mean value, as this value can be determined with a lower number of components than, for example, the root-mean-square value. Each short-time mean value G(n) is approximately a measure of the average power of the disturbed speech signals considered over a period of time of approximately 100 ms. This information and the sampling frequency also determine the number m of sampling values required to determine one of the short-time mean values G(n). If, for example, the disturbed speech signal is sampled with 10 kHz, then m must be approximately 1000. So each quantity G(1), G(2), . . . is obtained from approximately one thousand consecutive sampling values.
The unit GL of FIG. 1 effects a smoothing operation on the sequence of short-time mean values G(n). Further details about the object and the type and manner of smoothing are given hereinafter.
In parallel with the smoothing operation, an estimate P(n) is determined via the block PA of FIG. 1 for the average noise power, that is to say for the average power of the noise signals. More details of the estimate P(n) will also be given hereinafter. A comparator V in FIG. 1 compares a threshold S which depends on the estimate P(n) to the smoothed short-time mean values GG(n). If the smoothed short-time mean value GG(n) is less than the threshold S, a signal is conveyed to a unit EN. If the unit EN has received such a signal, for example at two consecutive clock instants T(n-1) and T(n) it reports by means of its own specific signal at a terminal A that a speech pause is present.
The diagram (a) of FIG. 2 shows a possible output signal AM of the mean-value producer M, that is to say a possible sequence of short-time mean values G(1), G(2), . . . . In diagram (a) the output signal AM is standardized such that its absolute maximum assumes the value 1. The amplitude thresholds shown in the drawing relate to the estimate P(n) (lower threshold, broken line) and to the threshold S (upper threshold, solid line). Diagram (b) shows schematically the associated speech signal S with its true pauses P. Should the determination of a pause be based on the fact that the higher amplitude threshold in diagram (a)--this pause determination is shown in diagram c--is fallen short of, then a plurality of faulty decisions would be obtained, as a comparison between the diagrams (b) and (c) shows. Shifting the upper threshold downwards would indeed result in the substantially total power reductions comprised in diagram (c), which are not based on speech pauses not being reported but the information about the length of the pauses would be significantly invalidated.
Therefore, the method according to the invention provides, before it is decided that there is a pause, a smoothing of the output signal AM, again with the aid of a linear digital filter, by means of which a value GG(n) of the smoothed signal is obtained from three consecutive short-time mean values G(n), G(n-1) and G(n-2), or with the aid of a median filter. The value of GG(n) may be ascertained from the formula ##EQU2## where c 0 , c 1 and c 2 are all greater than or equal to zero and their sum has a value equal to 1.
For the linear filtering operation a filter having the coefficients 1/4, 1/2 and 1/4 was found to be advantageous.
In the median filtering operation, five consecutive short-time mean values G(n) . . . G(n-4), for example, are arranged according to value and then the mean value is read as an output value GG(n) of the filter. Diagram (a) of FIG. 3 shows the aspect of the input signal of the mean-value producer N after smoothing with the aid of a linear digital filter. In diagram (b) the true speech sections and the true pauses in the speech signal are again shown schematically, and diagram (c) shows the speech sections and speech pauses such as they are obtained in analogy with diagram (c) of FIG. 1. Because of the linear smoothing operation, the number of faulty decisions is significantly reduced as can be seen from a comparison between FIG. 2 and FIG. 3. Also when smoothing is effected with the aid of a median filter the number of faulty decisions is reduced--as can be seen from diagram (c) of FIG. 4.
A further measure which prevents shorter substantially total power reductions in the disturbed speech signal from being erroneously considered as pauses, consists in that, for example, a substantially total power reduction is not considered as a speech pause until it has twice fallen short of the higher amplitude threshold in FIGS. 2, 3 or 4.
The amplitude thresholds shown in the FIGS. 2, 3 and 4 are, as already described in the foregoing, produced by the unit PA of FIG. 1, and more specifically the estimate P(n) of the noise power is first determined for each instant T(n). This quantity must be an approximate measure of the average power of the noise signal, the averaging period being in the order of magnitude of one second.
Whereas the estimate P(n) of the noise power during prolonged speech pauses--how these pauses are recognized will be described in greater detail hereinafter--is adjusted to an actual value, the method according to the invention provides good results also when the abovementioned average power of the noise signal changes only slowly, that is to say when they may be considered to be stationary in a time interval to the order of one or two seconds.
If the instant T(n) is present in a prolonged speech pause, than the estimate P(n) is determined again as a linear combination from the preceding estimate P(n-1) and the short time mean value G(n) in accordance with the equation
P(n)=(1-α)P(n-1)+αP(n)
The value of the constant α occurring in this equation is between 0 and 1. A typical value for α is 0.5. If no prolonged speech pause is present, then the preceding estimate is maintained, that is to say it is assumed that p(n)=P(n-1). A value zero is chosen for the estimate at the very beginning of the method.
To enable the recognition of prolonged speech pauses a continuous check is made whether the difference between two consecutive short-time mean value is, as regards their magnitude, below a threshold D. If, for example, K times consecutively the inequation
|G(n)-G(n-1)|<D=γG(n)
is satisfied, then this circumstance is considered to indicate the presence of a prolonged speech pause and the new estimate P(n) is determined in accordance with the above equation. The threshold D is chosen proportionally to the short-time mean value G(n), so as to obtain the same results when, for example, the level of all the signals is doubled. The proportionality factor γ and the number K can experimentally be determined such that the recognition method takes the lowest possible number of faulty decisions. Typical values are K=10 and γ=1.1.
Another way to obtain the best possible estimate P(n) for a slowly changing noise power consists in increasing at each sampling instant T(n) the estimate P(n-1) already present by a fixed amount c when the estimate P(n-1) is lower than the short-time mean value G(n). So each time the inequation P(n-1)<G(n) is satisfied, it is assumed that P(n)=P(n-1)+c.
The constant c can be chosen such that in the event of an unimpeded increase the estimate reaches the overload level in one to two seconds. If on the other hand the estimate P(n-1) already present is higher than the instantaneous short-time mean value G(n), then the new estimate P(n) is reduced with respect to the estimate present, more specifically in accordance with the equation
P(n)=(1-β)P(n-1)+βG(n),
which represents the new estimate as a linear combination of the preceding estimate and the instantaneous short-time mean value G(n). A reduction in the estimate can be recognized most distinctly when a value one is chosen for the constant β. Then, namely, it is obtained that P(n)=G(n)<P(n-1). However, values around 0.5 have been found to be more advantageous for the constant β.
The threshold S which is used to decide whether there is a pause or not is proportional to the estimate P(n). Typical for the relationship between the threshold S and the estimate P(n) is the equation S=1.1 P(n).
Thus, there is described one embodiment of the invention for recognizing speech pauses in a speech signal. Those skilled in the art will recognize yet other embodiments defined more particularly by the claims which follow. | Method of recognizing pauses in a speech signal when a slowly varying noise signal is superposed on the speech signal. For the purpose of pause recognition so-called short-time mean values connected with a clock pulse are continuously determined from the samples of the disturbed speech signal, which short time mean values are a measure of the average power of approximately 100 ms long sections of the disturbed speech signals. The sequence of these short-time mean values is then smoothed by linear filtration or by means of a median filter. In parallel with the smoothing operation an estimate for the noise signal power averaged over a few seconds is taken from the sequence of short-time mean values. If the smoothed short-time mean value is once or several times less than a threshold which is proportional to the above-mentioned estimate, then it is decided that there is a speech pause. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of use of teleconferencing systems. More particularly, the present invention relates to the dynamic launching of teleconferencing applications upon receipt of a call.
[0003] 2. Description of Related Art
[0004] Teleconferencing is increasingly becoming a popular application in personal computer systems. Such applications typically allow the transfer of audio and video data between users so that they can speak and otherwise communicate with one another. Such applications sometimes also include data sharing wherein various types of data such as documents, spreadsheets, graphic data, or other types of data, can be shared and manipulated by all participants in the teleconference. Different teleconference applications perhaps residing on different hardware platforms have different capabilities. Moreover, a wide variety of features has been implemented in different teleconference applications, and the proliferation of different types of computer systems with different capacities, and different networking media has created challenges for teleconferencing.
[0005] For example, most systems which are used for teleconferencing applications are also used to run such programs for performing word processing, spreadsheet applications, database applications, and a variety of other applications. Thus, the resources contained in the computer system are shared between these multiple applications. Often, most computer systems are limited in the amount of random access memory they contain and also the amount of processing power available for performing operations. In order for a user to receive calls, the user must keep the conferencing application open. Otherwise, if the called party does not have the conferencing application open, the calling party would receive a notice that the called party is not present to answer the call.
[0006] So, in order to receive a call, a user currently needs to keep any conferencing application open. However, keeping the conferencing application open is a waste of resources. Memory which is allocated to the conferencing application could be used for other applications. Also, processing resources are consumed in launching and maintaining the conferencing application. These resources are unnecessarily preoccupied for the times when there are no teleconferencing sessions in occurrence. A user can wait until he wishes to initiate a teleconferencing session before launching the teleconferencing application, but this means that there is no call notification unless the user receives a “regular” phone call, which does not allow for on-demand conferencing.
[0007] Thus, a solution needs to be provided that will allow a system to dynamically load the conferencing application only when necessary to answer a call, but not require the conferencing application to be loaded and executing to receive notice of an incoming call.
[0008] In addition, a solution should be provided that will allow a conferencing application to wait on incoming calls on various ports simultaneously, thereby allowing a conferencing application which can handle conferencing over several different network/conferencing protocols and/or interfaces to achieve parallel conferencing capabilities (i.e., answering multiple calls, each coming in on a different network protocol or a different conferencing interface).
[0009] Moreove, a solution needs to be provided for multiple conferencing applications, each compatible with a different set of network/conferencing protocols, to be able to listen for incoming calls at the same time.
SUMMARY OF THE INVENTION
[0010] The invention provides a method and apparatus for listening on multiple network/conferencing protocols and/or interfaces. In addition, multiple persistent listening for multiple ports can exist for multiple conferencing applications (i.e., one persistent listen to one conferencing application) AND for a single conferencing application (i.e., multiple persistent listen to one conferencing application). Thus, for example a conferencing application can listen for incoming calls on both a TCP/IP port or an AppleTalk™ port.
[0011] The invention can be implemented in a computer system having a memory, a processor, and a network interface, a method for dynamically launching a conferencing application upon the receipt of an incoming call comprising the steps of loading a set of transport components into the memory; initializing each transport components of the set of transport components to listen on a particular conferencing interface using the network interface, each transport component of the set of transport components listening to a different conferencing interface; receiving an incoming call signal on the network interface having an incoming conferencing interface; processing the incoming call signal to detect the incoming conferencing interface; and launching an application based on the incoming conferencing interface.
[0012] An apparatus including a set of transport components coupled to the network interface, each transport component of the set of transport components having the capability of receiving a signal on a different conferencing interface; a conference component coupled to each component in the set of transport components; a call processing module coupled to the conference component; and, a process manager coupled to the call processing module; the conference component containing a circuit for causing the call processing module to cause process manager to activate a conferencing application upon detecting a call from one transport component of the set of transport components.
[0013] The invention will allow a system to dynamically load a conferencing application only when necessary to answer a call, but not require the conferencing application to be loaded and executing to receive notice of an incoming call. In addition, different conferencing applications can also be “dynamically” launched when incoming calls corresponding to each different conferencing applications arrive.
[0014] Other objects, features and advantages of the invention will be apparent from the accompanying drawings, and from the detailed description that follows below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 illustrates an example configuration in which various embodiments of the invention may be implemented.
[0016] [0016]FIG. 2 illustrates a single system in which embodiments of the invention may be implemented.
[0017] [0017]FIG. 3 illustrates an example architecture on which a system employing various embodiments of the invention is based.
[0018] [0018]FIG. 4 illustrates a preferences file configured in accordance to the invention.
[0019] [0019]FIG. 5 illustrates a system employing various embodiments of the invention.
[0020] [0020]FIG. 6 illustrates a system employing various embodiments of the invention used for initializing persistent listening.
[0021] [0021]FIG. 7 illustrates a system employing various embodiments of the invention used for transfering an incoming call.
[0022] [0022]FIG. 8 is a flow diagram illustrating a prefered operation of the invention used for dynamically launching a conferencing application.
[0023] [0023]FIG. 9 illustrates a system employing various embodiments of the invention used for initializing a second persistent listening.
[0024] [0024]FIG. 10 illustrates a system employing various embodiments of the invention used for maintaining a second persistent listening on a second port.
[0025] [0025]FIG. 11 illustrates a system employing various embodiments of the invention used for receiving an incoming call on a first port.
[0026] [0026]FIG. 12 illustrates a system employing various embodiments of the invention used for receiving an incoming call on the second port while a call is received on a first port.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention provides a method and apparatus for dynamically launching teleconferencing applications upon receipt of a call. For purposes of explanation, specific embodiments are set forth to provide a thorough understanding of the present invention. However, it will be understood by one skilled in the art, from reading this disclosure, that the invention may be practiced without these details. Further, although the present invention is described through the use of certain specific embodiments thereof, especially, with relation to certain hardware configurations, data structures, packets, method steps, and other specific details, these should not be viewed as limiting the present invention. Various modifications can be made by one skilled in the art, without departing from the overall spirit and scope of the present invention.
[0028] A portion of the disclosure of this patent document contains material which is subject to copyright protection. They copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. Copyright Apple Computer, Inc.
[0029] A typical system configuration in which a teleconference may take place is illustrated as 100 in FIG. 1. For example, a first workstation 150 may communicate via teleconference with a second workstation 155 , as illustrated. System 150 may include a central processing unit 150 c which is coupled to a display 150 d a video input device 150 a , and a sound input device 150 b . The system 150 may communicate with over system 155 over networking medium 170 via network connection module 160 . Network connection module 160 may include any number of network adapters commercially available such as Ethernet, Token Ring, or any other networking standard commercially available. Note that network adapter 160 may also include a wireless network adapter which allows transmission of data between components without a medium 170 . Communication is thus provided via network adapter 165 coupled to system 155 , and bi-directional communications may be established between two systems. System 150 further has a keyboard 150 e and a pointing device 150 f , such as a mouse, track ball, or other device for allowing user selections and user input.
[0030] In implemented embodiments of the present invention, a general purpose computer system is used for implementing the teleconferencing applications and associated processes to be described here. Although certain of the concepts to be described here will be discussed with reference to teleconferencing, it is apparent that the methods and associated apparatus can be implemented for other applications, such as file sharing, real time data acquisition, or other types of applications which sends data from a first participant to a second participant or set of participants. A computer system such as that used for implementing embodiments of the present invention will now be described.
[0031] [0031]FIG. 2 is a diagram showing a computer system capable of implementing the present invention, such as a workstation, personal computer or other processing apparatus. The sub-system 300 comprises a bus or other communication means 301 for communicating information, and a processor 302 coupled with bus 301 for processing information. Sub-system 300 further comprises a random access memory (RAM) or other volatile storage device 304 (referred to as main memory), coupled to bus 301 for storing information and instructions to be executed by processor 302 . Main memory 304 also may be used for storing temporary variables or other intermediate information during execution of instructions by processor 302 . Sub-system 300 also comprises a read only memory (ROM) and/or other static storage device 306 coupled to bus 301 for storing static information and instructions for processor 302 , and a mass storage device 307 such as a magnetic disk or optical disk and its corresponding disk drive. Mass storage device 307 is coupled to bus 301 for storing information and instructions.
[0032] Sub-system 300 may further be coupled to a display 321 such as a cathode ray tube (CRT) or liquid crystal display (LCD) coupled to bus 301 for displaying information to a computer user. Such a display 321 may further be coupled to bus 301 for the receipt of video or image information. A keyboard 322 , including alphanumeric and other keys may also be coupled to bus 301 for communicating information and command selections to processor 302 . An additional user input device is cursor control 323 , such as a mouse, a trackball, stylus, or cursor direction keys, coupled to bus 301 for communicating direction information and command selections to processor 302 , and for controlling cursor movement on display 321 . For teleconferencing applications, system 300 may also have coupled to it a sound output device 328 , a video input device 329 , and sound input device 326 , along with the associated D/A (Digital-to-Analog) and A/D (Analog-to-Digital) converters or software codecs for inputting or outputting media signal bitstreams. System 150 c may further be coupled to communication device 327 which is coupled to network adapter 160 for communicating with other computers over network 370 .
[0033] Note, also, that any or all of the components of system 150 c and associated hardware may be used in various embodiments, however, it can be appreciated that any configuration of the system may be used for various purposes according to the particular implementation.
[0034] In one embodiment, system 300 is one of the Apple Computer® brand family of personal computers such as the Macintosh 8100 brand personal computer manufactured by Apple Computer, Inc. of Cupertino, Calif. Processor 302 may be one of the PowerPC brand microprocessors manufactured by Motorola, Inc. of Schaumburg, Ill.
[0035] Although a general purpose computer system has been described, it can be appreciated by one skilled in the art, however, that the following methods and apparatus may be implemented in special purpose hardware devices, such as discrete logic devices, large scale integrated circuits (LSI's), application-specific integrated circuits (ASIC's), or other specialized hardware. The description here has equal application to apparatus having similar function.
[0036] [0036]FIG. 3 illustrates a plurality of processes and/or apparatus which may be operative within system 150 c . At the highest level, for example, at the highest level in the ISO/OSI networking model, a conferencing application 401 , such as a teleconferencing application, an audio/video server, or a data server, communicates with a conference component 400 in the form of Application Program Interface (API) calls.
[0037] Conference component 400 allows conferencing application 401 to establish communications between two or more teleconference stations. Control information, and media information can be transmitted between the first participant system and a second participant system. Conference component 400 communicates with the transport component 402 by sending messages for other teleconferencing stations which are encapsulated and placed into a form that the transport component 402 , and the network component 403 , can packetize and transmit over networking medium 170 .
[0038] Transport component 402 and networking component 403 provide the necessary operations for communication over the particular type of network adapter 160 and networking medium 170 according to a particular implementation. For example, networking component 403 may provide the TCP or ADSP protocols and packetizing, according to those respective standards. Transport component 402 can support standards such as H.320 or MovieTalk™ transport standards. There can exist multiple transport components and multiple network components, as described below.
[0039] The main function of conference component 400 is to establish and maintain a bi-directional connection between every member of a conference—i.e., between conferencing applications. Conferencing applications use a control channel to exchange control data that is pertinent to the conference. This data might include user identification information or other information that is germane to the application's operation. Conferencing applications (e.g., conferencing applications 401 ) define the format and content of these control messages by establishing their own control protocols within the boundaries of the conferencing API. Conferencing components further establish communication channels between a first endpoint and a second endpoint, using underlying transport component 402 . Thus, once a media channel has been established, conference component 400 uses the media channel of transport component 402 which is provided for transmission of media and non-media information.
[0040] Conferencing application 401 controls conference component 400 by the issuance of QuickTime™ Conferencing API calls. Conferencing applications operate using an event-driven model wherein events pertinent to the application are issued to conferencing application 401 . Conferencing application 401 can then take appropriate action either by modifying internal data structures within (creating a source or sync), and/or issuance of appropriate messages over the network to other connected components, or potential participants. In addition, conference components also respond to events and messages that are received. In addition, conference components take appropriate actions pertaining to the receipt of API calls from conferencing applications.
[0041] There can exist multiple conferencing components, wherein each conferencing application requires at least one conference component, but each conferencing application can have more than one associated conference component. Each conferencing component has an unique identification number. In addition, each conference component contains one “listen string”, which is unique. A listen string is the encapsulation of the parameters of the “MTConferenceListen” API call for each conference component. Listen strings can contain more than one network or port. A listen string is composed of two parts: a fixed portion identifying a service name (which is similar to service names given to printers in an AppleTalk™ network that are displayed in the Chooser application in the Apple Macintosh operating system), and a variable portion containing a list of one or more service types, which contain the transport/network types with which the transport components and network components can interface. For example, service types can be port numbers for TCP/IP networks or device types for AppleTalk network. The transport/network tuples will be described below in association with the discussion of FIG. 5.
[0042] The system as shown in FIG. 3 requires that a conferencing application 401 be present to handle incoming call events generated by conference component 400 . As conferencing applications (such as conferencing application 401 ) utilize significant system resources (e.g., processor processing power and memory space), the requirement that conferencing application 401 be executing even when there are no calls present to necessitate the existence of a conferencing application prevents the use of those resources by other applications. A system that removes the requirement by allowing conferencing application 401 to be launched when needed (i.e., launching only when there is an incoming call to handle), is described below.
[0043] [0043]FIG. 5 illustrates a preferred embodiment of the invention having a call director 502 ; a demon conference component 504 (i.e., a conference component acting in demon mode); a transport component 506 ; and a network component 508 . The preferred embodiment also contains a call director preferences 510 . Call director 502 , demon conference component 504 , transport component 506 , and network component 508 can be referred to as call processing module.
[0044] Call director 502 is a “faceless” background process that is loaded at initialization of the computer system contained in FIG. 2. One of the main functions of call director 502 is to initiate the automatic launching of a conferencing application when a call is received by the computer system. In addition, call director 502 is responsible for initiating and interacting with demon conference component 504 to control the transfer of calls to a conferencing application. As a faceless process—i.e., a process that does not need to contain any code to interface directly with a user—call director 502 requires very little in terms of system resources. More importantly, aside from the indications given by the dynamic launching capabilities and other functionality provided by call director 502 , and the relatively small memory foot-print of call director 502 , the user does not even have to be aware that call director 502 is existent. Through the use of the elements contained in FIG. 5, conferencing application 401 does not have to be loaded and executing until an incoming call exists.
[0045] Demon conference component 504 , which is controlled by call director 502 through the use of the QuickTime Conferencing Application API, is responsible for performing the “persistent listening” for incoming calls. Demon conference component 504 is created by call director 504 after call director 504 has finished launching. Demon conference component 504 is an instance of the class of conference components that is initiated into a special mode of operation by call direction 504 through the use of a “MTConferenceSetPersistence” API call with the parameter “mtPersistenceDemonMode”.
[0046] In a preferred embodiment, there can only be one demon conference component in each computer system. Demon conference component 504 is the only conference component instance of call director 502 . That is, call director 502 can only have a single instance of a conference component (as opposed to conferencing application, which can have multiple conference component instances). Demon conference component 504 communicates with other conference components to transfer incoming calls indicated by transport component 506 and network component 508 using a shared data structure in memory. A preferred embodiment of the shared data structure is further described below, along with a description of the basic operations of the invention, while referencing FIG. 6.
[0047] [0047]FIG. 6 illustrates a sample configuration using the preferred embodiment of the invention wherein conferencing application 401 and conference component 400 interacts with call director 502 and demon conference component 504 through the use of a shared queue structure 512 .
[0048] Inter-Conference Component Communication
[0049] In the preferred embodiment, conference components communicate (i.e., achieve interprocess communication) through the use of shared memory. Specifically, conference components communicate through the use of globally accessible data structures composed of a demon queue and an application queue, both of which are contained in shared queue structure 512 . The demon queue is used by any conferencing component of a conferencing application to send commands and information to demon conferencing component 504 (“QdPersistenceon”, “QdPersistenceOff”, “QdListenAgain”, “QdPersistenceClear”). The application queue is used by the demon conferencing component to send messages to other conferencing components (“QdListenerStatus”, “QdDemonOff”, “QdIncomingCall”). It is to be noted that the choice of using queues to allow inter-component communication is not intended to be limiting, and other methods of allowing inter-component communication can be used to achieve the same functionality. For example, instead of using queues to transfer commands and information, messages can be passed from one conferencing component to another. Alternatively, registers may be used to pass information from one conference component to another.
[0050] In the following description of FIG. 6, it is assumed that call director 502 has been loaded at the time of initialization of the computer system, and call director 502 has created an instance of the class of conference components and initialized into that conference component instance into demon conference component 504 through the use of the “MTConferenceSetPersistence” API call with a parameter of “mtPersistenceDemonMode”. It is important that a demon conference component such as demon conference component 504 exists so as to perform persistent listening. If there is not a conference component in demon mode, there can be no persistent listening. Moreover, if a conferencing application tries to turn on persistent listening when there is no demon conference component initiated, the conference component of the conferencing application will return a “mtDemonKaputErr” message, indicating that there is no demon conference component to turn-on persistent listening.
[0051] Setting-Up Persistent Listening
[0052] As stated above, demon conference component 504 is responsible for listening for incoming calls on behalf of all conferencing applications that request persistent listening. Call director 502 is responsible for dynamically launching (if necessary) and transferring an incoming call to the conferencing application which requested persistent listening. The process for configuring demon conference component 504 and call director 502 in the preferred embodiment is as follows:
[0053] (1) conferencing application 401 will first send an “MTConferenceSetPersistence” API command with an “mtPersistenceOnMode” parameter after being launched to conference component 400 ;
[0054] (2) conference application 401 will then send an API command (“MTConferenceListen”) requesting persistent listening and passing a listen string, which includes the identification of the port on which it wishes demon conference component 504 to listen, to conferencing component 400 ;
[0055] (3) conference component 400 will place a request (QdPersistenceOn) on the demon queue to have demon conference component 504 perform persistent listening on the port specified by conferencing application 401 (the request containing an application signature, as discussed below, identifying conferencing application 401 as the requester and the parameters, or so-called “listen string”, of the listening that conferencing application 401 is requesting, the parameters including a service name and a port);
[0056] (4) demon conference component 504 will initialize transport component 506 and network component 508 as necessary to perform persistent listening on the requested service type and port;
[0057] (5) at substantially the same time as step (4), demon conference component 504 will also notify call director 502 through the use of a “mtPersistenceChangedEvent” that conferencing application 401 has requested persistent listening, and send the application signature of conferencing application 401 and the listen string, which, as stated, includes information regarding the service type and port on which conferencing application 401 wishes to listen;
[0058] (6) call director 502 will then store the information received from demon conference component 504 , including the application signature of conferencing application 401 (call director 502 will create an alias, as described below, for conferencing application 401 from the application signature), the service name, the transport type, the network type, and the service type into call director preferences 510 ; and,
[0059] (7) lastly, conferencing application 401 can either end execution or remain running—but under either case, the listening for incoming calls will be done by demon conference component 504 , as described below.
[0060] Persistent Listening of Incoming Calls
[0061] During normal operations, demon conference component 504 , after detecting an incoming call, will notify the conferencing application which requested the listening to transfer the incoming call. As mentioned above, in order to ensure that an incoming call can be matched-up with a conferencing application, call director 502 uses call director preferences 510 to track of the conferencing applications that requests persistent listening. Call director 502 also uses call director preferences 510 to track all listen strings of the various conference components corresponding to the various conferencing applications. Also as discussed above, each listen string corresponds to a particular conference component and contain the service and the ports for which that conference component is responsible. Thus, call director preferences 510 contains: (1) a list of aliases for conferencing applications that requested listening; and (2) what each conferencing applications want to listen on, such as the name of a user, the transport and the network type, and the service type (e.g., a port number for TCP/IP)).
[0062] [0062]FIG. 4 illustrates the contents of call director preferences 510 , displayed in content window 410 , containing logical representations of: a listen strings list 412 (“mtls”), and a conferencing application alias list 414 (“alis”). Call director 502 uses call director preferences 510 to keep track of the persistent listening requests of conferencing applications, and to hold the values used to initiate a demon conference components (e.g., demon conference component 504 ), any transport components (e.g., transport component 506 ), and any network components (e.g., network component 508 ). The contents of listen strings list 412 is displayed in a listen string list window 416 . The contents of conferencing application alias list 414 is displayed in a alias list window 418 .
[0063] As can be seen in listen string list window 416 , only one listen string, a listen string 420 , is contained in listen strings list 412 . Listen string 420 is identified in listen string list 412 by the unique identification number “20556”, which is the identification number used to identify related resources in call director preferences 510 . In addition, in listen string list window 416 , it is shown that listen string 420 was initialized by conferencing application 401 , which in this example is entitled “QuickTime™ Web Conference”. Thus, listen string 420 identifies that conference component 400 belongs to conferencing application 401 .
[0064] The contents of listen string 420 is displayed in a listen string content window 422 . Listen string 420 contains a service name 424 (“James Watt” in ASCII and a hexadecimal equivalent), a transport type 426 (“mtlktcpi” in ASCII and a hexadecimal equivalent), and a port 428 (“458” in ASCII and a hexadecimal equivalent). Thus, conferencing component 401 is the requester of persistent listening for transport type 426 and port 428 .
[0065] Referring still to FIG. 4, a conferencing application alias 430 is shown in conferencing application alias list 414 in alias list window 418 . Conferencing application alias 422 has an identification number 20556, which is the same identification number used to identify listen string 420 in call director preferences 510 . Conferencing application alias 422 is used by call director 502 to locate and launch conferencing application 401 (i.e., QuickTime™ Web Conference) when an incoming call matches the profile contained in listen string 420 . The aliases contained in conferencing application alias list 414 is kept in call director preferences 510 and only used by call director 502 —i.e. aliases are never passed down to demon conference component 504 .
[0066] The contents of conferencing application alias 430 is shown in alias content window 432 and contains the location of conferencing application 401 .
[0067] Answering of Incoming Calls After Persistent Listening has been Activated.
[0068] After persistent listening has been set-up, assuming that conferencing application is still running (see FIG. 6), when an incoming call is detected by transport component 506 , demon conference component 504 will transfer the incoming call to conferencing component 400 , which will notify conferencing application 401 of the incoming call. The incoming call is transferred through the following sequence:
[0069] (1) demon conference component 504 sends a “QdIncomingCall” message to conference component 400 through the use of shared queue structure 512 ;
[0070] (2) conference component 400 creates a new instance of a transport component and a new instance of a network component, which in FIG. 7 is transport component 402 and network component 403 , respectively;
[0071] (3) demon conference component 504 sends conference component 400 a reference to transport component 506 ;
[0072] (4) conference component 400 “answers” the call by sending a “MTTransportAnswer” message, along with the reference to transport component 506 , to transport component 402 instance to transfer the call from transport component 506 ;
[0073] (5) after the call has been transferred successfully, conference component 400 sends a “QdListenAgain” message to demon conference component 504 through the use of shared queue structure 512 ; and,
[0074] (6) demon conference component 504 issues a “MTTransportListen” API call to transport component 506 to await the next incoming call.
[0075] System Re-Initialization After Persistent Listening has been Initialized.
[0076] When the computer system is re-initialized and call director 502 is loaded and begins execution after system initialization, the following start-up sequence occurs:
[0077] (1) call director 502 reads call director preferences 510 and retrieves any listen strings;
[0078] (2) call director 502 initializes demon conference component 504 to place it into demon mode as described above;
[0079] (3) call director 502 sends one “MTConferenceDemonListen” API call to demon conference component 504 for each listen string that is retrieved from call director preferences 510 , where each API call passes demon conference component 504 the retrieved listen string and the associated application signature for the conferencing application that requested the listening.
[0080] Hi-Jacking of Listening
[0081] A later conferencing application will replace the listening of conferencing application 401 if the later conferencing application wants to listen to the same port (under TCP/IP) or the same name/device (under AppleTalk). If this occurs, a “mtListenHijackedErr”, generated by demon conference component 504 , will be received by conference component 400 if conferencing application 401 , which has been “hi-jacked,” is still running. Conference component 400 will then inform conferencing application 401 that the listening requested by conference component 401 has been taken over so that conferencing application 401 can take any necessary action.
[0082] In addition, demon conference component 504 will send a “MTConferenceSetPersistence” API call with the parameter of “mtPersistenceOffMode”, along with the application signature of conferencing application 401 , to call director 502 . Call director 502 will then remove the listen strings for conferencing application 401 from call director preferences 510 .
[0083] If conferencing application 401 is not running when a hi-jack occurs, then the “mtListenHijackedErr” will be removed after a certain time.
[0084] Turning Off Persistent Listening
[0085] If persistent listening is turned off for a listen string (i.e., a conference component), there will be no notification of incoming calls for that listen string if the conferencing applications that handles that listen string is not loaded and executing—i.e., the system will operate as it had before the existence of the invention. However, the user will continue to receive notification of incoming calls on the listen strings for which persistent listening has not been turned off.
[0086] The sequence to turn off persistent listening will depend on whether conferencing application 401 is loaded and executing. If conferencing application 401 is loaded and executing, then the sequence is as follows:
[0087] (1) conferencing application 401 sends conference component 400 a request to turn off persistent listening via a “MTConferenceSetPersistence” API call with “mtPersistenceOffMode” parameter;
[0088] (2) conference component 400 sends a “QdPersistenceoff” message to demon conference component 504 ;
[0089] (3) demon conference component 504 will then remove transport component 506 and network component 508 and send a “QdDemonOff” message to conference component 400 ;
[0090] (4) demon conference component 504 sends a “MTPersistenceChangedEvent” message to call director 502 with the application signature for conferencing application 401 ;
[0091] (5) call director 502 removes the listen string for conference component 400 from call director preference 510 ;
[0092] (6) conference component 400 , after receiving the “QdPersistenceOff” message from demon conference component 504 , will create a new instance of a transport component and a new instance of a network component and initialize them for local listening—i.e. conference component 400 will be responsible for waiting for an incoming call for the listen string.
[0093] If the user thereafter quits conferencing application 401 , then the system will operate as if call director 502 is not present and the user will receive no notifications of incoming calls as conferencing application is not loaded and executed to perform listening.
[0094] It is to be noted that as a listen string can have more than one transport component and network component created for persistent listening—e.g., a listen string contains the listening for both a TCP/IP port and a AppleTalk service—demon conference component 504 will have to remove all the transport components and network components associated with the listen string for which persistent listening is turned off in step (3). In addition, when those instances of transport components and network components are removed, the conference component which requests that persistence listening be turned off for its listen string (e.g., conference component 400 ) will have to create a new set of transport component and network component instances to continue listening in step (6).
[0095] For a user to turn off persistent listening for the services and port that conferencing application 401 processes if conferencing application 401 is not currently loaded and executing, the user has to first launch conferencing application 401 . Conferencing application 401 then reads its own preference files and performs listen with same values as it did the last time it executed (i.e., conference component 400 sends a listen request with the same listen string it sent to initiate persistent listening to demon conference component 504 ). Then, the same sequence used to turn off persistent listening is used, as described above.
[0096] Dynamic Launching of a Conferencing Application
[0097] [0097]FIG. 8 is a flow diagram of the preferred operation of the invention wherein call director 502 operates to dynamically launch a conferencing application after persistent listening has been initialized and an incoming call is received. The system in operation at the start of the flow diagram is as shown in FIG. 5.
[0098] In block 802 , call director 502 detects an incoming call through the use of demon conference component 504 and transport component 506 . Call director 502 is notified by an “mtIncomingCallForEvent”, containing an application signature of the conferencing application which set-up the listen string.
[0099] In block 804 , demon conferencing component 504 will place a “QdIncomingCall” message on the application queue with the application signature, listen string, identity of transport component 506 (i.e., a reference to transport component 506 ), and an “MTAddress” parameter, which identifies the address of the caller. Demon conference component 504 will also send an “MTIncomingCallForEvent” to call director 502 that an incoming call has been received along with an application signature and listen string for conferencing application 401 and conference component 400 . Call director 502 then checks the current process list to see if the conferencing application with the target application signature (i.e., conferencing application 401 ) is a process that is currently running. Operation will then continue with block 806 , as discussed below. If the conferencing application is not running, call director 502 will try to launch the conferencing application, as discussed in block 808 .
[0100] In block 808 , where the conferencing application is not currently executing, call director 502 will determine if the conferencing application is locatable so that it can be launched—i.e., whether the location of the conferencing application can be ascertained. Call director 502 will retrieve conferencing application alias 422 for conferencing application 401 from call director preferences 510 , update the location of conferencing application 401 if necessary, and then use the process manager to launch conferencing application 401 . If a conferencing application corresponding to conferencing application alias 422 cannot be found (e.g., where conferencing application 401 has been removed from the storage devices accessible to the computer system), then operations will continue with block 824 .
[0101] In block 810 , if conferencing application is locatable, call director 502 will determine whether there is enough free memory to run the conferencing application. If there is enough memory for conferencing application 401 to execute, call director 502 will then initiate the launching of conferencing application 401 continuing with block 812 .
[0102] If there does not exist enough memory for the conferencing application to execute, operations will continue with block 816 , where the user will be notified through an alert dialog that conferencing application 401 does not have enough memory to launch, and unless the user terminates and quits one or more processes that are currently occupying memory, the user will not be able to accept the incoming call. Call director 502 will keep checking for the user to free up memory until a predetermined time-out period has elapsed in block 818 . At the end of the time-out period, if the user has not freed-up enough memory, operation will continue with block 826 . If the user does free up enough memory, the operations will continue with block 812 .
[0103] In block 812 , where there exists enough memory for conferencing application 401 to begin execution, call director 502 will launch conferencing application 401 by using the process manager. Conferencing application 401 is notified that it must process the incoming call and therefore launches.
[0104] After conferencing application 401 has launched, the system configuration will be as shown in FIG. 6, where conferencing application 401 and its associated conference component 400 has loaded and is executing.
[0105] In block 814 , call director 502 checks to see if conferencing application 401 is listening in the same way as it was when the conferencing application set-up call director 502 for persistent listening. If conferencing application 401 does not listen in the same way within a reasonable time, demon conference component 504 recognizes that the incoming call has not been handled (i.e., the incoming call event has not been removed from the application queue) and will inform call director 502 with a “mtPersistenceChangedEvent” with the “mtPersistenceOffMode” parameter and the application signature of conferencing application 401 . Call director 502 will then remove the entry for conferencing application 401 from call director preference file 510 in block 824 , as described below. If conferencing application 401 is listening in the same way, then conferencing application 401 is transferred the incoming call as in block 806 .
[0106] In block 806 , and referring to FIG. 7, after the conferencing application has completed launching, or if the conferencing application is already executed, call director 502 will transfer the incoming call to the conferencing application, as described above, and return to listening, as discussed in block 822 , below.
[0107] After conferencing application 401 has been transferred the call, conferencing application 401 will then be responsible for giving the user an option to accept the call. If the user decides to accept the call, then conferencing application 401 will perform as usual an process the incoming call. If the user does not accept the call, then operation will continue with block 820 . It is to be noted that whether or not the user decides to accept the call, call director 502 is not affected after call director 502 has transferred the incoming call to conferencing application 401 and returns to listening, as discussed in block 822 .
[0108] In block 822 , after either: (1) call director 502 has transferred the incoming call to the conferencing application as in block 806 ; or (2) demon conference component 504 has dropped the call—i.e. removed the call from the incoming call event queue—as in block 826 , demon conference component 504 will return to listening.
[0109] In block 824 , where conferencing application 401 is not locatable or conferencing application 401 is not listening using the same values with which conferencing application 401 set-up call director 502 , call director 502 will remove all references to conferencing application 401 from call director preferences 510 .
[0110] In block 826 , if there is not enough memory available to launch conferencing application 401 and the user does not free-up any memory within the time-out period in block 816 , then the incoming call will not be answered and the caller will receive a notice that the user the caller is trying to contact is not available. The incoming call will also be dropped if conferencing application 401 is not listening in the same way as it was when conferencing application 401 set-up call director 502 to listen for incoming calls. If there is not enough memory available to launch conferencing application 401 and the user does not free-up any memory within the time-out period in block 816 , then the system will be the one shown in FIG. 5, where conferencing application 401 and conference component 400 are not executing. If conferencing application 401 is not listening in the same way as it was when conferencing application 401 set-up call director 502 to listen for incoming calls, then the system will be as shown in FIG. 6, where conferencing application 401 and conference component 400 are executing even though they are not processing any incoming calls.
[0111] Listening on Multiple Ports by Multiple Conferencing Applications
[0112] [0112]FIG. 9 illustrates a preferred embodiment of the invention for initiating persistent listening on multiple ports where the system of FIG. 6 (wherein conferencing application 401 and conference component 400 has set-up persistent listening, as discussed above) now includes a second conferencing application 518 and a second conference component 520 . Second conferencing application 518 and second conference component 520 is launched and initiated the same way as conferencing application 401 and conference component 400 .
[0113] It will be recalled that in the discussion of FIG. 6, transport component 506 and network component 508 have been initialized to listen for an incoming call matching the parameters of the listen string belonging to conferencing application 401 . Now, in FIG. 9, second conferencing application 518 wishes to set-up persistent listening under a different set of parameters (e.g. under AppleTalk, versus TCP/IP for conferencing application 401 ). The sequence followed by second conferencing application 518 is identical to the sequence performed by conferencing application 401 , except for the different value of the listen string passed to demon conference component 504 and call director 502 to set-up a different transport component and a different network component.
[0114] In FIG. 9, before second conferencing application 518 has requested and set-up persistent listening, there is only persistent listening being performed for conferencing application 401 . After second conferencing application 518 has set-up persistent listening, the system will be as shown in FIG. 10.
[0115] In FIG. 10, after second conferencing application 518 has set-up persistent listening, a second transport component 514 instance and a second network component 516 instance has been created to perform the listening requested by second conferencing application 518 . Second transport component 514 and second network component 516 are identical to transport component 506 and network component 508 , except that they are set-up to listen for incoming calls having the parameters of the listen string of second conference component 520 .
[0116] In FIG. 11, an incoming call has come in matching the parameters of the listen string for conference component 400 and demon conference component has transferred the incoming call to conferencing 401 , as discussed above.
[0117] In FIG. 12, while conferencing application 401 is processing the incoming call received in FIG. 11, an incoming call has come in for second conferencing application 518 and has been transferred to second conferencing application 518 through the creation of a third transport component 522 and a third network component 524 to
[0118] Thus, the explanation give above in FIGS. 5 - 8 can be modified by substituting second conferencing application 518 , second conference component 520 , third transport component 522 , third network component 524 , second transport component 514 and second network component 516 for conferencing application 401 , conference component 400 , transport component 402 , network component 403 , transport component 506 and network component 508 , respectively, with the exception that there would now be a different listen string for second conference component 520 . In addition, listen strings list 412 and conferencing application alias list 414 in FIG. 4 would contain an additional listen string for second conference component 518 and an additional alias for second conferencing application 520 , respectively. For example, if second conferencing application 518 is not loaded when an incoming call matching the parameters of the listening requested by second conferencing application 518 came in, then second conferencing application 518 and second conference component 520 would be dynamically launched to handle the incoming call as discussed in FIG. 8.
[0119] It is to be noted that not only can persistent listening for multiple ports can exist for multiple conferencing applications, multiple persistent listening can exist for a single conferencing application if there is more than one service in the listen string of the conference component of that conferencing application, as mentioned above.
[0120] While the present invention has been particularly described with reference to the various figures, it should be understood that the figures are for illustration only and should not be taken as limiting the scope of the invention. Many changes and modifications may be made to the invention, by one having ordinary skill in the art, without departing from the spirit and scope of the invention. | In a computer system having a memory, a processor, and a network interface, a method for listening on multiple conferencing interfaces having the steps of loading a set of transport components into the memory; initializing each transport components of the set of transport components to listen on a particular conferencing interface using the network interface, each transport component of the set of transport components listening to a different conferencing interface; receiving an incoming call signal on the network interface having an incoming conferencing interface; processing the incoming call signal to detect the incoming conferencing interface; and launching an application based on the incoming conferencing interface.
An apparatus for listening on multiple conferencing interfaces having a set of transport components coupled to the network interface, each transport component of the set of transport components having the capability of receiving a signal on a different conferencing interface; a conference component coupled to each component in the set of transport components; a call processing module coupled to the conference component; and, a process manager coupled to the call processing module; the conference component containing a circuit for causing the call processing module to cause process manager to activate a conferencing application upon detecting a call from one transport component of the set of transport components. | 7 |
This is a continuation of application Ser. No. 893,921, filed Aug. 6, 1986, which was abandoned upon the filing hereof.
FIELD OF THE INVENTION
The invention relates to an applicator device for a liquid product contained in a bottle, a device of the kind comprising an applicator brush carried by a cap, or similar, intended to close the neck of the bottle and to be fixed on this neck with the brush situated inside the bottle.
The invention concerns more particularly but not exclusively, applicator devices for nail varnish.
PRIOR ART
It is known that the use of such applicator devices comprising a brush necessitates frequent immersion of the brush in the liquid for replenishing it with the product.
To remedy this drawback, it has already been proposed to use "marker" type applicators which, however, do not allow liquids to be used having formulas approximately to the traditional formulas, in particular in the field of nail varnish. These applicators, moreover, pose problems of sealing and generally comprise relatively complicated valve mechanisms.
OBJECTS OF THE INVENTION
The principal object of the invention is to provide an applicator device for a liquid product, of the kind defined above, such that it meets the various practical requirements better than heretofore.
It is a further object of the invention to make it possible to reduce substantially the number of times necessary for immersing the brush in the bottle to spread the product.
It is yet another object of the invention to provide such an applicator device comprising a brush which is always in contact with liquid, once the cap is replaced on the bottle, which prevents the brush from drying out.
SUMMARY OF THE INVENTION
These objects, as well as others which will emerge below, are attained by an applicator device for a liquid product contained in a bottle comprising an applicator brush which is formed by a stem carrying at one end a tuft of hairs and being joined at its opposite end to a cap or the like, intended to close the bottle neck and to be fixed on this neck with the brush situated inside the bottle, the said applicator device comprising reservoir means capable of storing some liquid product of the bottle in order to feed the hairs of the applicator brush when the brush is withdrawn from the bottle with a view to applying some of the product, these reservoir means being capable of replenishment between two uses of the brush. The said reservoir means are constituted by an interstice formed between the applicator brush and a tubular sleeve surrounding it and whose base is in contact with the hairs of the brush when the brush is withdrawn from the bottle.
In accordance with a first embodiment of the present invention, the reservoir means are provided in the brush stem which stem comprises a hollow portion constituting the interstice delimited by the wall forming the downwardly open sleeve of the stem, the hairs of the brush being accommodated in the interstice.
Advantageously, the hairs of the brush are embedded in the bottom of the hollow portion of the stem and extend over the whole length of this hollow portion, while spreading out to project outside the said hollow portion.
Generally, an air hole is provided in the wall surrounding the hollow portion towards the centre of this portion to facilitate replenishment of the stem interior.
The applicator device preferably comprises a wiper mounted inside the bottle neck and fitted in its lower portion with a lip capable of wiping the stem when it is withdrawn from the bottle, the air hole being provided in the wall of the stem so as to be located below the wiper when the brush is fitted on the bottle.
In accordance with a second embodiment of the present invention, the sleeve fixed in relation to the brush comprises at least one notch in the free edge of the sleeve opposite the portion of the set of hairs of the brush which is next to the stem. In particular, the or each notch is V-shaped.
In accordance with a particular embodiment of the present invention, the sleeve forms an element attached to the applicator brush and comprises fixing means complementary to the means carried by the applicator brush.
The fixing means carried by the sleeve consist, for instance, of an internal catch-engagement bead engaging complementary fixing means carried by the applicator brush and consisting of an external groove intended to accommodate the said catch engagement bead.
Preferably, the sleeve is cylindrical with a circular cross-section whose axis is identical with that of the applicator brush, the brush stem comprising: a portion with an oval cross-section in the region adjacent to the tuft of hairs of the brush; and, on the opposite side from the tuft near the transition zone with the cap, a portion whose cross-section is a cylindrical shell of a circular cross-section and which comprises, over at least one circular cross-section cylindrical sector, the means fixing the said applicator brush to the sleeve by catch-engagement. In particular, the portion of the stem whose cross-section is cylindrical is delimited by two opposite cylindrical sectors and by two opposite half-flats parallel to the axis of the applicator brush, these half-flats being situated in the extension of the greatest curvature walls of the oval cross-section portion of the stem.
The tuft of hairs of the brush of the device in accordance with the present invention may, in particular, have a flattened shape; in that case, it is advantageous to provide a notch disposed opposite the median longitudinal plane of the tuft of hairs.
In accordance with another characteristic of the device, the applicator brush enters the bottle via an opening edged by the pliable lip of a wiper cooperating with the external wall of the sleeve.
In accordance with a third embodiment, the reservoir means may comprise a sleeve slidably mounted in the cap, provision being made for elastic means for straining the sleeve in such a way that, when the cap is fitted on the bottle, the sleeve is pushed back towards the end panel of the cap so as to release that portion of the stem next to the hairs of the brush and, when the cap is removed, the sleeve is displaced by the elastic means and surrounds the above-mentioned portion of the brush stem as far as the base of the brush hairs, some of the liquid product being trapped between the brush stem and the sleeve.
Preferably, the elastic means comprise a helical spring mounted between the cap and a tubular member inside the cap and on which the brush stem is fixed, this tubular member serving for guiding the displacement of the sleeve.
The bottle is fitted with a duct mounted inside its neck. The base of this duct constitutes a stop for the sleeve when the cap is mounted on the bottle to push the sleeve back into a high position.
The stem supporting the brush may have an undulating shape in its portion situated near the hairs of the brush.
In the first and third embodiments of the present invention it may be advantageous for the internal portion of the brush stem or of the sleeve to comprise capillary striations.
BRIEF DESCRIPTION OF THE DRAWINGS
Apart from the features set out above, the invention involves several other objects and advantages which will be discussed in greater detail below in connection with particular but non-restrictive embodiments, described with reference to the accompanying drawings.
In these drawings:
FIG. 1 is a transverse cross-section of a bottle provided with an applicator device in accordance with a first embodiment of the invention;
FIG. 2 is a cross-section along line II--II of FIG. 1;
FIG. 3 is an axial cross-sectional view of a bottle provided with an applicator device according to a second embodiment of the present invention, the stem of the applicator brush being partly shown in elevation;
FIG. 4 is a cross-sectional view along line IV--IV of FIG. 3, FIG. 3 itself being an axial cross-section along line III--III of FIG. 4;
FIG. 5 is a partly cross-sectional and partly elevational view of the applicator device of FIG. 3, viewed at an angle displaced by 90° in relation to the representation of FIG. 3;
FIG. 6 is an axial cross-section of a bottle provided with an applicator device in accordance with a third embodiment of the invention; and
FIG. 7 shows the bottle of FIG. 6 when the cap has been withdrawn therefrom.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawing, there can be seen an applicator device 1 for a liquid product L contained in a bottle 2. In the example considered, the liquid product is nail varnish.
The device 1 comprises an applicator brush 3 which is carried by a cap 4 or the like intended to close the neck 5 of the bottle and to be fixed on this neck with the brush 3 situated inside the bottle. Generally the neck 5 comprises an external thread 6 capable of cooperating with a conjugate internal thread 7 of the cap 4 to fix the cap in place. The bottle 2 is generally made of glass, whilst the cap 4 is made of a plastic material, in particular polypropylene.
The brush 3 comprises a tuft of hairs 8 carried by a stem 9 whose upper portion forms a head 10 with a larger diameter, held in a recess 11 of the cap 4. At its base, the head 10 comprises a peripheral flange 12 axially abutting a shoulder 13 marking the separation between the larger diameter internal portion of the cap 4 and the inlet of the recess 11. The head 10 is fixed in the recess 11 by any appropriate means, in particular by force-fitting or bonding.
The applicator device 1 comprises reservoir means R capable of storing some of the liquid product L of the bottle so as to feed the brush 3 when the brush has been withdrawn from the bottle 2 with a view to applying this liquid product.
In accordance with the embodiment of FIGS. 1 and 2, reservoir means R are provided in the stem 9 whose diameter is relatively large. This stem 9 comprises a hollow portion 14 opening towards the bottom 15 of the bottle and accommodating the hairs 8 of the brush. The reservoir means R, that is to say, the chamber corresponding to the hollow portion 14, are capable of replenishment by capillarity when the hairs 8 of the brush are immersed in the liquid product L.
This hollow portion 14 constitutes a chamber or an interstice, of cylindrical shape, delimited by the wall 17 forming the sleeve of the stem 9. It is coaxial with the stem 9 and is open at its lower portion. The hairs 8 of the brush are embedded in the bottom 9' of the hollow portion and extend over the whole length of this hollow portion 14, while spreading out to project outside the said hollow portion 14. The hairs 8 form a brush of the type used for water colours which has the advantage, in contrast to the conventional nail varnish brushes generally used, of ensuring an effective control of the flow and discharge of the varnish. There is an air hole 16, in the wall 17 surrounding the hollow portion, and situated substantially towards the centre of this hollow portion to facilitate replenishment of the interior of the stem 9 with the liquid product L. As may be seen in FIG. 2, the hollow portion of the stem 9 comprises capillary striations 18 orientated parallel to the axis of the stem and promoting the rising and retention of the liquid product in the hollow portion 14.
A wiper 19 of a pliable material, in this case an elastomeric material, is mounted inside the neck 5 and is provided in its lower portion with a lip 20 surrounding the stem 9 on which it exerts a light pressure.
The wiper 19 comprises, in its upper portion, a radially outwardly projecting flange 21 capable of bearing against the end of the neck and of being gripped between the end of the neck 5 and the flange 12 referred to above.
The position of the air hole 16, and the axial dimension of the wiper 19, are chosen so that the air hole 16 is located as shown in FIG. 1 below the lip 20 of the wiper when the brush 3 is in the bottle. The pressure inside the hollow portion 14 is thus in balance with the pressure in the bottle 2.
The lower end 22 of the stem 9 forming the base of the chamber 14 is in contact with the hairs of the brush. The upper end 23 of the stem 9 forms a frusto-conical transition zone to the head 10.
The operation and use of the applicator device 1 are as follows.
When the cap 4 is screwed on the neck 5 of the bottle 2, the brush 3 is located inside the bottle. When the hairs 8 of the brush penetrate into the liquid product L, in this case the varnish, the product rises by capillarity along the hairs as far as the hollow portion or chamber 14 of the stem 9, thus forming a reservoir. This rising of the liquid product is facilitated by the presence of the air hole and the capillary striations 18.
When the stopper 4 is unscrewed and the brush 3 is withdrawn from the bottle 2, the stem 9 is wiped by the lip 20 of the wiper. The reservoir of the liquid product remains in the hollow portion 14.
The application of the liquid product, namely nail varnish, then takes place. In the course of the application by the hairs 8, the liquid product contained in the hollow portion 14 feeds the hairs, thanks to the striations 18, until this hollow portion 14 has become empty.
With such a suitably dimensioned applicator device 1, especially as regards the hollow portion 14, it is possible to apply the nail varnish over the whole hand without having to reimmerse the hairs 8 of the brush 3 in the liquid product of the bottle.
FIGS. 3 to 5 relate to a second embodiment of the present invention wherein those elements which are similar or equivalent to the elements already described with reference to FIGS. 1 and 2 are designated by the same numerals followed by the letter a. Their description will not be repeated, or if so then only briefly.
A wiper 19a of pliable material, in particular of an elastomeric material, is mounted inside the neck 5a and is provided, in its lower portion, with a lip 20a surrounding the sleeve attached to the applicator brush 3a (which sleeve will be described below) whereon it exerts light pressure.
The wiper 19a comprises, at its upper portion, a radially outwardly projecting flange 21a capable of bearing on the end of the neck 5a and of being gripped between the end of the neck 5a and the flange 12a of the head 10a of the applicator brush 3a described below.
The brush 3a comprises hairs 8a carried by a stem 9a whose upper portion forms a head 10a secured in a recess 11a of the cap 4a. The head 10a and the stem 9a proper are joined by transition zone 23a of a generally frusto-conical shape.
The stem 9a comprises, successively between the hairs 8a and the head 10a: a portion 36 of an oval cross-section as may be seen in FIG. 4; and a portion which is of smaller height than the portion 36 and which is delimited on the one hand by two opposite sides 38 forming two sectors of one and the same cylinder whose axis is identical with the axis of the stem 9a and two opposite half-flats 39 parallel to the axis of the stem 9a. The two portions of the stem 9a are joined by a shoulder 40 flaring from the portion 36 towards the other portion.
Moreover, in each of the walls 38, there is an annular groove 41 situated in a plane perpendicular to the axis of the stem 9a near the transition zone 23a of the stem to the head 10a, each groove extending from one edge to the other of the respective part cylindrical wall 38.
The head 10a, having an overall cylindrical shape, is secured in a recess 11a of the cap 4a. It comprises at its base, that is to say near the zone 23a, the above-mentioned peripheral flange 12a, which axially abuts a shoulder 13a, marking the separation between the larger diameter internal portion of the cap 4a and the inlet of the recess 11a. Moreover, in the end wall of the head 10a is a cylindrical cut out 42 whose axis is identical with that of the applicator brush 3a. To facilitate the insertion of the said applicator brush 3a in the recess 11a, the free external edge of the head 10a is chamfered. The head 10a is fixed in the recess 11a by an appropriate means, in particular by force-fitting or bonding.
The applicator device 1a comprises reservoir means R capable of storing some of the liquid product L of the bottle 2a so as to supply the applicator brush 3a when the brush is withdrawn from the bottle 2a for application of the product.
These reservoir means R are formed by the interstice existing between the stem 9a and the adjacent portion of the set of hairs 8a, and a cylindrical external sleeve 44 fixed to the stem 9a. For this purpose the sleeve 44 has, near its edge on the opposite side to that facing the tuft of hairs 8a, an internal peripheral ring 45 intended to cooperate with the grooves 41 in the cylindrical sectors 38, these latter being situated in the extensions of the smaller curvature walls of the portion 36 of the oval section of the stem 9a.
Moreover, along its lower edge 22a opposite the hairs 8a in the mounted position of the said sleeve 44, the sleeve 44 comprises a V-shaped notch 46. As may be seen in FIGS. 3 and 5, the tuft of hairs 8a has a flattened shape. It is arranged that in the final position, the notch 46 is situated opposite the median longitudinal plane of the said tuft of hairs 8a.
The mounting of the sleeve 44 on the applicator brush 3a is extremely simple since it suffices to slide the sleeve 44 around the end of the stem 9a carrying the hairs 8a until the retaining ring 45 becomes catch engaged in the grooves 41, and then to adjust the sleeve 44 by rotation so that the notch 46 has precisely the desired position in relation to the set of hairs 8a.
When the cap 4a is screwed on to the neck 5a of the bottle 2a, the applicator brush 3a is inside the bottle 2a. When the hairs 8a penetrate into the liquid, e.g. nail varnish, the liquid rises by capillarity along the hairs 8a up to the interstice forming the reservoir R.
When the stopper 4a is unscrewed, and the brush 3a is withdrawn from bottle 2a, the sleeve 44 is wiped by the lip 20a of the wiper 19a. The reservoir R of the liquid product remains in the above mentioned interstice.
The application of the liquid product can then be effected. In the course of this application, the liquid contained in the reservoir R feeds the hairs 8a, and this is facilitated by the presence of the notch 46, until this reservoir R has become exhausted.
With such a suitably dimensioned applicator device 1a, particularly as regards the reservoir R, it is possible to apply the nail varnish over the whole of one hand without having to re-immerse the hairs 8a of the applicator brush 3a in the liquid of the bottle 2a.
FIGS. 6 and 7 show another embodiment wherein those elements which are similar or equivalent to the elements already described with reference to FIGS. 1 and 2 are designated by the same numerals followed by the letter b. Their description will not be repeated or if so then only briefly.
The reservoir means R comprise a sleeve 24 slidably mounted to the cap 4b. Elastic means E restrain the sleeve 24 so that when the cap 4b is fitted on the bottle 2b, the sleeve 24 is biased towards the bottom of the cap so as to release the portion 25 of the stem next to the hairs 8b of the brush whilst, during the removal of the cap 4b, the sleeve 24 comes to surround the above-mentioned portion 25 of the stem, under the action of the elastic means, as far as the base of the hairs 8b of the brush.
The elastic means E are advantageously provided between the bottom of the cap 4b and the sleeve 24. Preferably, these elastic means E are formed by a helical spring 26 mounted inside the cap around a tubular member 27 integral with the cap and coaxial with it. The stem 9b of the brush is fixed at its head 10b in the lower open end of the tubular member 27.
The sleeve 24 comprises a lower portion 28 of smaller diameter, within which the stem 9b slides with restricted play, and an upper portion 29 of larger diameter in which the tubular member 27 is fitted with restricted play. This tubular member 27 thus serves to guide the sliding displacement of the sleeve 24. The transition between these two portions 28 and 29 is at a frusto-conical zone 30.
The portion 28 of sleeve 24 comprises, internally, longitudinal capillary striations similar to the striations 18 of FIG. 2.
The bottle 2b is provided with a duct 31 mounted inside its neck 5b. The base 32 of this duct forms a stop for the lower end of the sleeve 24 when the cap 4b is fitted on the bottle 2b. This stop 32 biases the sleeve 24 into a high position against the spring 26 as shown in FIG. 6.
The stem 9b, provided with hairs 8b, preferably has an undulating shape in its portion 25 situated near the hairs of the brush. This undulating shape may be obtained by a succession of spherical or substantially spherical bulges joined by smaller diameter zones 34. This undulating shape favours the retention of some of the liquid product on the portion 25. The hairs 8b are fixed at the base of this portion 25 which they extend.
The passage opening 35 of the duct 31 has a larger diameter than the maximum diameter of both the stem 9b and the stem lower portion 25.
The functioning and use of the applicator device 1b of FIGS. 6 and 7 are as follows.
When the stopper 4b is screwed onto the bottle 2b, the lower end of the sleeve 24 abuts the base 32 of the duct 31 and this pushes the sleeve 24 against the spring 26, as shown in FIG. 6.
The portion 25 of the stem 9b penetrates into the bottle 2b with the hairs 8b and they become impregnated with the liquid product L.
When the cap 4b is unscrewed, the stem 9b takes out, essentially by means of its portion 25, a certain quantity of liquid adhering to its surface.
Because of the larger diameter of the opening 35 the portion 25 of the stem is not wiped, and the liquid product is placed in reserve within the sleeve 24, and more particularly the portion 28 is not wiped, when the portion 25 of the stem enters the sleeve, as shown in FIG. 7.
In the position of use, shown in FIG. 7, the sleeve 24 comes into contact at its lower end 22b with the base of the hairs 8b of the brush, so as to ensure that the brush is properly fed by the reserve stored in the sleeve 24, and in particular by the striations (similar to the striations 18) which serve as reservoir.
The application of the product, e.g. to the fingernails, is then effected in the conditions explained above with reference to FIGS. 1 and 2.
It is also possible to apply the nail varnish over the whole of one hand without having to recharge the brush with the product by re-immersion in the bottle 2b.
The tuft of hairs 8b of FIGS. 6 and 7 preferably has a "tear drop" shape allowing the flow to be controlled.
Whatever the embodiment, once the cap has been screwed back onto the bottle, the brush is always in contact with the liquid product L and does not dry out.
The explanations given above make it clear that the reserve means R are capable of replenishment between two uses of the brush, each use following a removal of the cap from the bottle.
As can be understood, in the three embodiments described above the reservoir means R are situated outside the hair tuft of the applicator brush (3,3a,3b): because of this, the liquid product L does not pass between the hairs (8,8a,8b) fixed in the stem (9,9a,9b) but instead passes axially along the outer surface of the tuft. | An applicator for a viscous liquid such as nail varnish has an applicator brush in the form of a tuft of hairs which is anchored at its upper end in an applicator stem and a part of the tuft downwardly of the point of anchorage is surrounded by a reservoir space R into which an optional air hole passes. While the applicator brush is being used, varnish or other liquid passes axially along the tuft from the reservoir R, thereby increasing the duration of an applicator phase before the need to reimmerse the tuft in the liquid product L in the bottle. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus and process for pickling a continuous strip material in the form of a continuous sheet or continuous wire. The invention is particularly directed to an apparatus having guiding mechanisms for the continuous strip material for feeding the strip material in several loops having vertical sections and liquid delivery devices to bring the strip material into contact with the pickling liquid.
BACKGROUND OF THE INVENTION
[0002] Various continuous pickling devices are known in the art for applying a pickling liquid to a continuously moving strip of material. Many of these devices include a bath where the strip material is immersed in the bath as it is conveyed through the device. Other continuous pickling devices including one or more sprayers to spray a continuous stream of the pickling liquid onto the surfaces of the continuous strip.
[0003] Another type of pickling apparatus is disclosed in Austrian Patent No. 206247 B1. This patent discloses a pickling apparatus having a pickling tower that contains one or more vertically oriented loops of the continuous strip material. Spray nozzles are provided in the tower to apply the pickling medium directly to the strip material.
[0004] A similar apparatus is disclosed in Austrian Patent No. 218331 B1. The patent discloses the pickling apparatus having a pickling tower where the pickling medium is sprayed onto the strip material which is guided vertically in several loops. The apparatus includes a concentric nozzle surrounding the strip material so that the pickling medium flows downward over the strip material. The pickling apparatus disclosed in these patents provide a long length of the strip material that is subjected to the pickling liquid while minimizing the floor space required for the apparatus.
[0005] These prior pickling apparatus that include vertical sections have a fixed length of the strip material that is contacted with the pickling medium. Thus, it is not possible to vary the pickling effect by changing the length of the strip material that is contacted with the pickling medium such as in purely chemical pickling processes. Conventional horizontal pickling tanks where the strip material is fed through a pickling tank filled with the pickling medium do not allow variation in the pickling effect by the pickling medium. One proposal to control the pickling effect is disclosed in German Patent Application No. 4240572 A1. The apparatus disclosed in this patent application having horizontal sections includes additional injection nozzles within the pickling tanks to control the amount of the pickling medium contacting the strip material. This apparatus does not allow the control of the pickling action in selected areas or to distinguish between areas within the pickling tank where a strong pickling action takes place compared to a poor pickling action. In addition, this apparatus has a predetermined length of the pickling tank and the length of the strip material that is subjected to the pickling medium.
[0006] Another example of a horizontal pickling tank is disclosed in U.S. Pat. No. 4,807,653, which discloses a series of consecutive pickling cells. The pickling cells are sealed off by rollers at each end which convey the strip material through the apparatus. The rollers do not permit complete separation of the individual pickling cells or sections. Although the squeezed rollers remove a portion of the pickling medium, there is always a certain amount of the pickling medium that remains on the strip material and is carried into the subsequent pickling cells. The pickling medium is also carried into the rinse station where the strip material is contacted with a rinsing or flushing medium. This apparatus also does not allow a change in the length of the strip material that is subjected to the pickling medium.
[0007] The prior pickling apparatus are generally effective for their intended use but have experienced various limitations. Accordingly, there is a need in the industry for an improved pickling apparatus and process for controlling the pickling effect on the strip material.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to a process and apparatus for pickling a continuous strip of material such as a continuous sheet or continuous wire-shaped material. The invention is also directed to an apparatus that is able to control the effective length of the strip material within the pickling apparatus, control the extent of the pickling effect on the strip material and to control the effective length of the strip material that is contacted with the pickling medium.
[0009] Accordingly, a primary aspect of the invention is to provide a pickling apparatus that is able to select and change the effective pickling length of a strip material within the pickling apparatus in a precise manner. The effective pickling length as used herein refers to the length of the section of the strip material that is being contacted with and treated by the pickling medium at any one time as the continuous strip material is conveyed through the pickling apparatus.
[0010] A further aspect of the invention is to provide a pickling apparatus and process that can be a purely chemical pickling process where the pickling effect is controlled and adjustable while reducing the amount of floor space required for the pickling plant and apparatus.
[0011] Another aspect of the invention is to provide a pickling apparatus and process where the apparatus includes a plurality of liquid treating cells arranged in sequence where each of the cells can be selectively controlled to control the pickling effect on the continuous strip material within the respective pickling cell.
[0012] Still another aspect of the invention is to provide a pickling apparatus and process where the apparatus includes a plurality of guide members for feeding a continuous material in a serpentine path defining a plurality of loops where each loop defines a pickling cell. The supply and flow of pickling medium delivered to each of the pickling cells is monitored and controlled to control the effect of the pickling medium on the length of the continuous material within the respective pickling cell and the pickling effect of the continuous material as it moves continuously through the apparatus.
[0013] A further aspect of the invention is to provide an apparatus having at least two vertical pickling cells where each of the pickling cells includes two vertical sections of the strip material that is subjected to the pickling medium. The supply of the pickling medium to each of the individual pickling cells is activated and deactivated independently of one another to selectively control the amount of the pickling medium supplied to the strip material within a respective pickling cell and within the entire apparatus. In this manner, the pickling effect on the strip material can be controlled without changing the speed of the strip material through the apparatus. The vertical arrangement of the pickling cells allows a large pickling length of the strip material to be treated and allows selected changes in the effective length of the strip material that is subjected to the pickling medium. Selectively and independently activating or deactivating the entire pickling cell or portions of the pickling cell provides improved drainage of the pickling medium from the strip material to reduce the amount of pickling medium that is transferred to subsequent cells or to the rinsing station.
[0014] A further aspect of the invention is to provide a pickling apparatus having a plurality of pickling cells where each of the pickling cells include a guide assembly for defining at least two vertical sections in the strip material being processed. A liquid supply device is positioned to supply a flow of the pickling medium against each of the vertical sections of the strip material. The supply devices for each of the vertical sections are connected to a control device to selectively control the flow of the pickling medium to each of the supply devices and independently of one another within a pickling cell. Selectively actuating each of the liquid supply devices effectively subdivides the pickling apparatus into pickling zones so that each pickling zone can be controlled to adjust the effective length of the strip material being subjected to the pickling medium.
[0015] Another aspect of the invention is to provide a pickling apparatus and process having at least five pickling cells provided in sequence where each of the pickling cells include two vertical sections of the continuous strip material. Each of the vertical sections include a supply device for supplying a pickling medium to each of the vertical sections. By selectively controlling the supply devices and controlling the amount of the pickling medium directed to the strip material, the effective length of the strip material subjected to the pickling medium can be adjusted between 0 and 100% in 10% increments, thereby providing precise adjustments in the extent of the pickling process that is desired.
[0016] The various aspects of the invention are basically attained by providing a pickling apparatus for pickling a continuous material. The pickling apparatus comprises a first liquid treating cell that has a feed device for continuously feeding the continuous material in a substantially vertical loop with first and second vertical sections. A first fluid supply device supplies the pickling liquid onto the continuous material on the first and second vertical sections. At least one second liquid treating cell has a feed device for receiving the continuous material from the first liquid treating cell and continuously feeding the continuous strip in a substantially vertical loop which has first and second vertical sections. A second fluid supply device supplies the pickling liquid onto the continuous material on the two vertical sections. A control device is connected to the first liquid supply device and to the second liquid supply device for independently controlling a flow of the pickling liquid from the first liquid supply device and the second liquid supply device.
[0017] The aspects of the invention are also attained by providing a pickling apparatus for pickling a continuous material. The pickling apparatus comprises a plurality of liquid pickling cells arranged in sequence for treating the continuous material with a pickling liquid. Each of the liquid pickling cells has a first guide roller at a top end of the treating cell and a second guide roller at a bottom end of the cell for guiding the continuous material in a substantially vertical loop which has a first vertical section extending between the first guide roller and second guide roller and a second vertical section extending between the second guide roller and a first guide roller of an adjacent liquid pickling cell. Each cell has a liquid supply device for supplying the pickling liquid to the first and second vertical sections of the continuous material. A control device is coupled to the liquid supply for selectively and independently controlling the supply of pickling liquid to each cell.
[0018] The various aspects of the invention are further attained by providing a process of pickling a continuous steel material. The process comprises the steps of feeding the continuous steel material through a plurality of sequentially arranged liquid treating cells. Each of the cells has an upper guide roller and lower guide roller to guide the steel material in a substantially U-shaped loop within each of the cells and form a first and second vertical section. A dispensing device is provided in each of the cells for directing a pickling liquid onto each of the first and second vertical sections. Each dispensing device is selectively controlled to selectively operate the dispensing device within a cell independently of the operation of a dispensing device of another cell.
[0019] These and other aspects of the invention will become apparent from the following detailed description of the invention, which in conjunction with the annexed drawings, disclose various embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0020] The following is a brief description of the drawings in which:
[0021] [0021]FIG. 1 is a schematic view of the pickling apparatus in one embodiment of the invention showing the pickling cells of the apparatus arranged in sequence;
[0022] [0022]FIG. 2 is a schematic diagram of the pickling apparatus in another embodiment of the invention showing a first section having a plurality of pickling cells arranged in sequence followed by a second section positioned downstream of the first section of pickling cells; and
[0023] [0023]FIG. 3 is a schematic diagram of another embodiment of the invention showing the plurality of pickling cells arranged in first and second sections and a supplemental spray nozzle for supplying additional pickling medium to the strip material.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention is directed to an apparatus and process for contacting a continuous material with a treating liquid. The invention is particularly directed to an apparatus and process for supplying a pickling liquid medium to a continuous material in a controlled manner to control the pickling effect on the continuous material. The apparatus and process are able to control the pickling effect within selected pickling cells in the apparatus and control the complete pickling effect as the continuous material passes through the apparatus.
[0025] The continuous material that is treated by the apparatus and process of the invention is typically steel or stainless steel. The steel or stainless steel continuous material can be a hot rolled or a cold rolled steel or stainless steel as known in the art. The continuous material can be in the form of a continuous strip or sheet or in the form of a wire or rope. As used herein, the continuous material or continuous strip material refer to a continuous substrate that can be in any suitable shape or form that can be continuously fed through the apparatus and continuously treated with a pickling solution. The continuous material is supplied from a supply roll or manufacturing facility, fed through the pickling apparatus and recovered on a spool.
[0026] The pickling medium is typically a pickling acid or mixed acid as known in the art of pickling steel and stainless steel. The pickling acid can include an acid selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, phosphoric acid, and mixtures thereof.
[0027] [0027]FIG. 1 is a schematic diagram of a pickling apparatus in a first embodiment of the invention. Referring to FIG. 1, apparatus 10 includes a feed and guide assembly 12 for continuously feeding a continuous material 14 through apparatus 10 in a substantially serpentine path. The continuous material hereinafter is referred to as strip material 14 which can be in any suitable form such as a sheet, flat strip, wire or rope. Guide assembly 12 defines a plurality of pickling cells 16 arranged in sequence from an inlet end 18 to an outlet end 20 .
[0028] Strip material 14 is guided around a first guide roller 22 positioned at the inlet end 18 of assembly 10 . Guide roller 22 receives strip material 14 from a supply (not shown) and directs the strip material in a substantially downward direction to a second guide roller 24 . Second roller 24 is positioned below first guide roller 22 to direct strip material 14 in a substantially vertical path while continuously conveying strip material 14 through apparatus 10 . The length of strip material 14 extending between first guide roller 22 and second guide roller 24 defines a first vertical section within the respective pickling cell 16 . An upper roller 26 is positioned above second roller 24 and adjacent the first guide roller 22 to direct strip material 14 upwardly from second roller 24 and to define a second vertical section of strip material 14 extending between second roller 24 and upper roller 26 . First guide roller 22 , second roller 24 and upper roller 26 define a first of the pickling cells 16 for treating strip material 14 with a pickling liquid.
[0029] As shown in FIG. 1, a plurality of the upper rollers 26 are spaced apart along the length of apparatus 10 . A plurality of lower rollers 24 are also spaced apart and oriented to align with upper rollers 26 for continuously guiding strip material 14 in the serpentine path. Each of the lower rollers 24 cooperate with upper rollers 26 to define the respective pickling cells 16 and to form a first vertical section 28 and a second vertical section 30 of strip material 14 within each cell 16 . As shown in FIG. 1, each upper roller 26 cooperates with two adjacent pickling cells 16 to guide strip material 14 from second vertical section 30 of a first pickling cell to a first vertical section 28 of an adjacent pickling cell 16 . As shown, first vertical section 28 and second vertical section 30 of strip material 14 are substantially parallel and oriented substantially perpendicular to the longitudinal dimension of apparatus 10 . In this manner, each pickling cell 16 includes two vertical sections of strip material 14 . It is to be understood that strip material 14 is preferably being continuously conveyed through apparatus 10 so that the various sections of strip material 14 are intended to refer to the strip material within a specified area at any one time.
[0030] In the embodiment illustrated in FIG. 1, apparatus 10 includes five pickling cells 16 arranged in sequence for continuously receiving strip material 14 and providing an effective pickling length for treating the strip material. The outlet end 20 of assembly 10 includes a guide roller 8 positioned above the downstream lower roller 24 for directing strip material 14 to a subsequent processing station or to a suitable winding roll as desired. A squeeze or press roller 34 is provided at outlet end 20 to cooperate with second guide roller 32 to remove the pickling medium or rinse medium from strip material 14 before exiting apparatus 10 . Although five pickling cells 16 are illustrated in the embodiment of FIG. 1, the actual number of pickling cells can vary depending on the spacing between the lower rollers 24 and the upper rollers 26 and the desired effective length of the pickling zone subjected to the pickling medium.
[0031] The height of the individual pickling cells 16 can vary depending on the number of pickling cells within apparatus 10 and the desired maximum and/or minimum effective pickling length of the strip material to be treated with the pickling medium. Typically, each vertical section of strip material 14 within each pickling cell 16 has an effective pickling length of about 1 to about 10 meters, with lengths between about 3 and 6 meters being preferred. In more preferred embodiments, the effective pickling length for each vertical section of strip material 14 within each pickling cell is about 3.5 meters. In this manner, the effective pickling length of apparatus 10 is about 35 meters in the embodiment of FIG. 1 where five pickling cells 16 are provided. By arranging the upper and lower rollers to form the serpentine path of the strip material 14 , the horizontal length of apparatus 10 is typically about 10 meters, which is less than ⅓ of the length of a conventional horizontal pickling line apparatus.
[0032] Referring to FIG. 1, a liquid supply device 36 is provided within each pickling cell 16 for supplying a pickling medium to strip material 14 as it is conveyed through each pickling cell 16 . Typically, liquid supply device 36 is positioned at an upper end within each pickling cell 16 so that the pickling medium is supplied to strip material 14 at an inlet end of each pickling cell 16 .
[0033] In preferred embodiments, liquid supply device 36 includes two liquid dispensing units 38 within each pickling cells 16 . Liquid dispensing units 38 in the embodiment illustrated include a spray nozzle 40 positioned on opposite sides of strip material 14 to direct a spray 42 of the pickling medium against opposite sides of strip material 14 . Preferably, liquid dispensing units 38 are positioned at an upper end of first horizontal section 28 and second horizontal section 30 so that the pickling medium flow downward over the sections of strip material 14 . Liquid dispensing units 38 in one embodiment also include a dam 44 to form an overflow 46 of the pickling medium to ensure a continuous layer of the pickling medium on first vertical section 28 and second vertical section 30 of strip material 14 within each pickling cell 16 . Overflow 46 of pickling medium flows downwardly to provide continuous coating of strip material 14 with the pickling medium.
[0034] In preferred embodiments, each liquid dispensing unit 38 is supplied with the pickling medium through a conduit 48 which is connected to a main supply line 50 . Each conduit 48 includes a control valve 52 for independently controlling the flow of the pickling medium to each spray nozzle 40 . Each valve 52 is connected to a control device 54 . Control device 54 selectively actuates each valve 52 independently of one another to control the flow and supply of the pickling medium to each horizontal section within a given pickling cell 16 and to control the flow of pickling medium independently to each of the pickling cells 16 . Control device 54 can be a microprocessor or other suitable control device capable of selectively actuating each valve 52 as known in the art. Control device 54 is able to selectively activate or deactivate liquid dispensing units 38 by opening and closing valves 52 within each of pickling cell 16 independent of the treating process in another cell.
[0035] A collection tank 56 is positioned below each pickling cell 16 to collect the pickling medium that drains from strip material 14 as it passes through each of the pickling cells 16 . Collection tank 56 includes an outlet pipe 58 which supplies the collected pickling medium to a pump 60 . Pump 60 pumps the pickling medium from collection tank 56 to supply line 50 to recirculate the pickling medium. A suitable filter 62 and a feed device 64 for supplying fresh or regenerated pickling acid to the system are included in supply line 50 . In this embodiment, a single collection tank 56 is provided to collect the spent pickling medium that drains from the individual pickling cells.
[0036] In one embodiment, apparatus 10 can include an adjusting assembly 66 connected to one or more of lower rollers 24 to selectively adjust the height of lower roller 24 with respect to the adjacent upper rollers 26 . Adjusting assembly 66 is capable of selectively adjusting the height of the lower roller 24 to increase or decrease the length of a first vertical section 28 and a second vertical section 30 in a respective or adjacent pickling cells 16 . In this manner, the effective pickling length of the strip material can be selectively adjusted.
[0037] Control device 54 selectively operates valves 52 to control the flow of pickling medium within apparatus 10 and to control the amount of pickling medium that contacts the strip material 14 . In one embodiment, control device 54 can actuate each valve 52 to supply pickling medium to each spray nozzle 40 and the amount of pickling medium supplied to each spray nozzle 40 to provide a maximum pickling effect on strip material 14 . In embodiments where it is unnecessary or undesirable to treat strip material 14 with a maximum amount of the pickling medium that is capable of apparatus 10 , control device 54 can selectively and independently close one or more valves 52 to reduce the flow of pickling liquid that is supplied to strip material 14 . Valves 52 can be closed in a respective pickling cell 16 so that no pickling medium is supplied to strip material 14 in the respective pickling cell 16 . When valves 52 of a pickling cell 16 are closed so that no pickling medium is supplied, it is generally preferred to deactivate one or more of the pickling cells at the upstream end of apparatus 10 . In other embodiments, a single valve 52 for each pickling cell 16 is closed so that only one of the two spray nozzles in each pickling cell 16 supplies pickling medium to the strip material 14 . Either of valves 52 can be deactivated depending on the desired pickling effect.
[0038] In embodiments where one or more of valves 52 are closed, the rinse liquid can be supplied to the strip material to keep the strip material wet or damp, thereby avoiding streaking or staining. In one embodiment, mist projector or mist spray devices 68 are provided in at least one pickling cell 16 that is capable of supplying a rinsing liquid to contact strip material 14 . In one embodiment, mist spray device 68 is operatively connected to control device 54 to control the timing and amount of the spray, and to activate and deactivate mist spray device 68 . Typically, mist spray device 68 forms a light mist or spray of a rinse liquid that is sufficient to prevent strip material from drying without completely rinsing strip material as in a conventional rinsing station. The mist spray device 68 is preferably positioned next or proximate dispensing units 38 on both sides of continuous strip material 14 as shown in FIG. 1. Mist spray devices 68 arranged close to liquid dispensing units 38 can provide a continuous mist that can rinse along the vertical sections of the continuous strip material to prevent the continuous strip material from coming into contact with the atmosphere, thereby preventing or inhibiting oxidation. In one embodiment, mist spray devices 68 are actuated in response to a deactivation of liquid dispensing unit 38 in a respective liquid treating cell to prevent continuous strip material 14 from drying and being exposed to the air. In the embodiment illustrated, the downstream liquid treating cell includes mist spray devices 68 , although more than one or all of the cells can be provided with mist spray devices.
[0039] Apparatus 10 generally uses a chemical pickling process where the strip material is treated with a pickling acid or mixed acid. In one embodiment, apparatus 10 can include electrodes 70 to apply an electric potential to one or more sections of strip material 14 . As shown in FIG. 1, electrodes 70 are connected to one upper roller 26 and lower roller 24 within a pickling cell to apply an electric potential to strip material 14 within the respective pickling cell. Electrodes 70 are connected to a suitable electric power source 72 . The current and voltage applied to electrodes 70 are as known in the art for the electrolytic treatment of steel and stainless steel. In the illustrated embodiment, one section is provided with electrodes to electrolytically treat the strip material. In other embodiments, more than one section or pickling cell can electrolytically treat the strip material.
[0040] The effective length of the treatment within each pickling cell 16 is dependent on the distance between spray nozzles 40 and lower rollers 24 . Preferably, liquid dispensing units 38 provide a continuous flow of the pickling medium to form a continuous film that flows downwardly toward lower roller 24 . In one embodiment, liquid dispensing units 38 can be mounted on an adjustable rack 74 for selectively adjusting the height of liquid dispensing units 38 with respect to lower roller 24 within a given pickling cell 16 .
[0041] [0041]FIG. 2 shows a pickling apparatus 80 in a second embodiment of the invention. Pickling apparatus 80 is similar to the embodiment of FIG. 1 so that identical elements are identified by the same reference number with the addition of a prime. As shown in FIG. 2, apparatus 80 includes a plurality of lower rollers 24 ′ and upper rollers 26 ′ to guide strip material 14 ′ in a serpentine path through apparatus 80 . Liquid dispensing units 38 ′ are provided within each pickling cell 16 ′ to supply pickling medium to first vertical section 28 ′ and second vertical section 30 ′ within each pickling cell 16 ′.
[0042] In the embodiment of FIG. 2, apparatus 80 has a first pickling section 82 positioned upstream with respect to apparatus 80 and a second pickling section 84 positioned downstream of first pickling section 82 . An upper roller 86 is positioned to guide strip material 14 ′ from first pickling section 82 to second pickling section 84 . A press roller 88 cooperates with roller 86 to remove the pickling medium from strip material 14 ′ before feeding strip material 14 ′ to second pickling section 84 .
[0043] First pickling section 82 includes a collection tank 90 positioned below the respective pickling cells 16 ′ for collecting the pickling medium. In the embodiment illustrated, first pickling section 82 includes three pickling cells 16 ′. The collected pickling medium is directed by a pump 92 to a supply line 94 . Supply line 94 supplies the pickling medium through valves 52 ′ and conduits 48 ′ as in the previous embodiment. A collection tank 96 is positioned below pickling cells 16 ′ of second section 84 to collect the pickling medium draining from strip material 14 ′. The pickling medium is supplied by a pump 98 to a supply line 100 . Supply line 100 feeds the pickling medium through valves 52 ′ of conduits 48 ′ to liquid dispensing units 38 ′ within second pickling section 84 .
[0044] In the embodiment of FIG. 2, first pickling section 82 and second pickling section 84 supply a pickling medium to the continuous strip 14 ′. Control device 54 ′ independently actuates each dispensing unit 38 ′ within each of the pickling cells 16 ′ of first pickling section 82 and second pickling section 84 . In one embodiment, second pickling section 84 can include a rinse liquid to rinse the pickling medium from strip material 14 ′ before discharging from pickling apparatus 80 .
[0045] In FIG. 3, another embodiment of the pickling apparatus 104 is shown. Pickling apparatus 104 is substantially similar to apparatus 10 and apparatus 80 so that identical elements are identified by the same reference number with the addition of a prime.
[0046] Liquid dispensing units 38 ′ include an overflow to form a waterfall-like flow of the pickling medium onto strip material 14 ′. The continuous flow of the pickling medium produces a highly turbulent descending film along strip material 14 ′ as it is conveyed through apparatus 104 . In the embodiment of FIG. 3, secondary spray nozzles 106 are provided within one or more of pickling cells 16 ′ to direct a supplemental spray of the pickling medium onto strip material 14 ′. As shown in FIG. 3, a supply line 110 extends from collection tank 90 ′ to four secondary spray nozzles 106 positioned on opposite sides of strip material 14 ′. A high pressure pump 112 is provided to supply the pickling medium from first collection tank 90 to secondary spray nozzles 106 . In alternative embodiments, spray nozzles 106 can be connected to a rinse liquid such as water to direct a rinse liquid directly to strip material 14 ′.
[0047] In the operation of apparatus 104 , selected pickling cells 16 ′ and liquid dispensing units 38 ′ can be deactivated to selectively control the effective length of the pickling treatment of strip material 14 ′. Typically, pickling cells 16 ′ at the upstream end of apparatus 104 are deactivated when less than all of the pickling cells 16 ′ are required to supply the pickling medium. Secondary spray nozzles 106 can supply a rinse liquid to strip material 14 ′ within the upstream pickling cell 16 ′ to keep strip material 14 ′ wet or moist to prevent streaking and staining.
[0048] While various embodiments of the invention have been described herein, it will be appreciated that various changes and modifications can be made without departing from the scope of the invention as defined in the appended claims. | A device for pickling strip-shaped or wire-shaped material has guiding mechanisms for feeding and guiding the material in a serpentine path formed by several loops having vertical sections and liquid delivery devices positioned to bring the material into contact with a pickling liquid. At least two vertical pickling cells are provided in the apparatus, each with two vertical sections. Each of the individual cells are activated and deactivated optionally and independently of one another to be able to change or set the effective pickling length exactly, even in purely chemical pickling processors, and thus obtain a precisely definable, variable pickling effect, while retaining the space-saving design of the plant. | 2 |
CROSS REFERENCE TO RELATED APPLICATION(S)
This application is a 35 U.S.C. §371 National Phase Entry Application from PCT/EP2009/065782, filed Nov. 24, 2009, designating the United States, the disclosure of which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
The present invention relates to methods, nodes, arrangements and articles of manufacture for automatically identify unknown identities of a target.
BACKGROUND
Lawful Interception of communications can be made based on knowledge of the identity of a party responsible for transmitting or receiving the communication. For example if a mobile telephone number of a criminal suspect is known, it is possible to intercept or retain electronic communication sent from or received by the criminal suspect's mobile telephone. In governments around the world, various law enforcement agencies may have the right to authorize this interception in their respective jurisdictions.
FIG. 1 is part of the prior art and discloses an Intercept Mediation and Delivery Unit IMDU, also called Intercept Unit. The IMDU is a solution for monitoring of Interception Related Information IRI and Content of Communication CC for the same target. The different parts used for interception are disclosed in current Lawful Interception standards (see 3GPP TS 33.108 and 3GPP TS 33.107—Release 7). A Law Enforcement Monitoring Facility LEMF is connected to three Mediation Functions MF, MF 2 and MF 3 respectively for ADMF, DF 2 , DF 3 i.e. an Administration Function ADMF and two Delivery Functions DF 2 and DF 3 . The Administration Function and the Delivery Functions are each one connected to the LEMF via standardized handover interfaces HI 1 -HI 3 , and connected via interfaces X 1 -X 3 to an Intercepting Control Element ICE in a telecommunication system. Together with the delivery functions, the ADMF is used to hide from ICEs that there might be multiple activations by different Law Enforcement Agencies. Messages REQ sent from LEMF to ADMF via HI 1 and from the ADMF to the network via the X 1 _ 1 interface comprise identities of a target that is to be monitored. The Delivery Function DF 2 receives Intercept Related Information IRI from the network via the X 2 interface. DF 2 is used to distribute the IRI to relevant Law Enforcement Agencies LEAs via the HI 2 interface. The Delivery Function DF 3 receives Content of Communication CC, i.e. speech and data, on X 3 from the ICE. Requests are also sent from the ADMF to the Mediation Function MF 2 in the DF 2 on an interface X 1 _ 2 and to the Mediation Function MF 3 in the DF 3 on an interface X 1 _ 3 . The requests sent on X 1 _ 3 are used for activation of Content of Communication, and to specify detailed handling options for intercepted CC. In Circuit Switching, DF 3 is responsible for call control signaling and bearer transport for an intercepted product. Intercept Related Information IRI, received by DF 2 is triggered by Events that in Circuit Switching domain are either call related or non-call related. In Packet Switching domain the events are session related or session unrelated. Lawful Interception needs specific target information to be activated on a suspect. Law Enforcement Authorities receive the mandate to intercept a certain person usually from a judge. Their first task is to discover the target identities that they can use to activate LI. If the user has a subscription with a telecom operator it is rather straightforward to ask the operator for this information and then activate the interception on the discovered identities. In most cases criminals carry a personal phone which is registered to them and is used solely for legally uncompromising communications, e.g. with family members. The smarter criminals will never compromise themselves on these registered known phones due to their knowledge of Lawful Interception of communications. What they usually do is to get one or more additional secret “identities” by for example using SIMs registered to someone else or buying a prepaid SIM card with a small initial amount which has only to be registered at the first refill. With no known link to the criminal's name or knowledge of these unknown identities, the authorities are powerless to intercept the illegal conversations.
The problem at hand is thus how to discover efficiently additional target identities of a well known person having a known identity and who is a subject of lawful interception due to a judicial warrant.
SUMMARY
The present invention relates to a problem how to automatically identify unknown identities associated to a known identity of a target that is subject of lawful monitoring due to a judicial warrant, which unknown target identities are necessary to perform Lawful Interception. This problem and others are solved by the invention by mechanisms that make use of geographical positioning features and that make a crosscheck between positioning indicators until a single or a restricted number of target identities in a mobile network are identified.
More in detail, by tracing a number of locations where the known identity of the target has been present and collecting from a mobile network all mobile subscribers known to the network to be present in target areas covering these locations, a single or restricted number of subscriber identities can be identified as the only ones present in all areas at collection time. The method comprises the following steps:
positioning indicators indicating presence of a known identity of the target in at least one location are periodically collected;
at least one mobile network is interrogated and lists of identities of users located in defined target areas, each area covering at least one of the collected positioning indicators, are fetched;
a crosscheck between the fetched lists is performed; and
a single or restricted number of identities that is common to the fetched lists is identified.
In one aspect of the invention a Lawful Interception embodiment is disclosed. Real time data is collected from positioning indicators and lists of identities are fetched from mobile networks.
An object of the invention is to enhance the Lawful Interception solution in order to ensure automatic discovering of unknown target identities associated to a well known target identity that is subject of lawful monitoring due to a judicial warrant.
Other than with the above-mentioned method, this object and other are achieved by a node to automatically identify unknown identities of a target associated to a known identity thereof, where the node comprises:
means for periodically collecting positioning indicators indicating presence of a known identity of the target in at least one location, means for sending a request to monitor users present in a target area covering a collected positioning indicator, and means for receiving a list of user identities.
Furthermore, the above object and others are achieved by an arrangement to automatically identify unknown identities of a target associated to a known identity thereof, where the arrangement comprises:
means for periodically collecting positioning indicators indicating presence of a known identity of the target in at least one location, means for interrogating at least one mobile network to fetch lists of identities of users located in at least one target area covering at least one collected positioning indicator, means for crosschecking between the fetched lists, and means for identifying a single or restricted number of identities that is common to the fetched lists.
The means adopted in the nodes and arrangements of the present invention can be circuits, processors, electronic components, parts or subparts, chips, boards, computer readable program codes, computers, or combinations or groups thereof, and the like.
The above object and others are also achieved by an article of manufacture comprising a program storage memory having computer readable program code embodied therein to automatically identify unknown identities of a target associated to a known identity thereof, the program code comprising:
computer readable program code able to collect positioning indicators indicating presence of a known identity of the target in at least one location, computer readable program code able to interrogate at least one mobile network to fetch lists of identities of users located in at least one target area covering at least one collected positioning indicator, computer readable program code able to crosscheck between the fetched lists, and computer readable program code able to identify a single or restricted number of identities that is common to the fetched lists.
An advantage with the invention is that an agency will be able to identify for example additional phone numbers or mobile identities of a suspect in an automatic way when a specific mobile phone number or identity of the individual is known. In these way commonly used techniques, such as using for example anonymous prepaid subscriptions to elude monitoring can be neutralized.
The invention will now be described more in detail with the aid of preferred embodiments in connection with the enclosed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is part of the prior art and discloses a block schematic illustration of an Intercept Mediation and Delivery Unit attached to an Intercepting Control Element.
FIG. 2 is a block schematic illustration disclosing a target area within a operator network and the arrangement of units up to the Law Enforcement Agency LEA.
FIG. 3 is a block diagram showing the steps taken to automatically discover unknown identities through the Spatial Trigger Functionality “Any phone within the area”.
FIG. 4 discloses a signal sequence diagram representing collecting and handling of various data in a Lawful interception environment.
DETAILED DESCRIPTION
FIG. 2 discloses a telecommunication system. The system comprises in this example one Operator Network ON 1 . A target known identity T, i.e. a mobile phone identifier of subject under interception, can be seen in FIG. 2 . The identity can be for example one of MSISDN, IMEI and IMSI codes commonly associated to a mobile phone subscription. The target is present in a target area TA in this example, having entered it at a certain moment (arrow IN) and going to exit it at a certain subsequent moment (arrow OUT). The Operator Network ON 1 comprises two cell areas C 1 and C 2 . A Mobile Switching Centre MSC controls the cell areas C 1 and C 2 . In the example of the figure the target area TA partially overlaps the two cell areas C 1 and C 2 , and can be defined as a “shape” (a circle, an oval, a polygon, etc.) but it can also be defined to coincide with one cell, for example C 1 or C 2 , or with a group of cells, for example the group resulting from the combination of cell C 1 and cell C 2 . A Lawful Interception unit IMDU (Intercept Mediation and Delivery Unit) is disclosed in FIG. 2 . This IMDU has similar functionalities as the IMDU discussed in the BACKGROUND ART section of this application, and is operatively connected to a Law Enforcement Agency LEA for reporting information about the subject under interception. This IMDU is sometimes also referred to as LI-IMS (Lawful Intercept Mediation System).
Between the IMDU and the MSC is interposed a Gateway Mobile Positioning Centre (GMPC) which is part of a mobile positioning system which provides location based services. More specifically, the GMPC can perform several functions related to the geographical location of cell phones. Of particular interest for the present invention is the functionality “Any phone within an area” through which the GMPC can interrogate the Operator Network ON 1 and retrieve a snapshot of all the subscribers within a given area, for example the target area TA of FIG. 2 . The general configuration and operation of a GMPC within a mobile positioning system is generally known and will not be described further in detail unless it is necessary for the proper understanding of the present invention.
For a better understanding of the invention, a typical although non-limiting scenario is now described by way of example, with reference to FIG. 3 . The target is under interception via his known identity, e.g. MSISDN. The process of automatically identifying his other unknown identity or identities starts at 501 . The position of the target, i.e. the location of his known identity, regardless his telephone activity, is periodically reported in step S 02 . At each positioning report received, the functionality “Any phone within the area” (S 03 ) is activated to retrieve a list, e.g. a MSISDN list S 04 , of all identities within the target area defined the position of the known identity.
It is to be noted that the specific target area can be selected amongst a group of areas (which are predetermined areas corresponding to a shape, a cell or group of cells) as the geographical area comprising the geographical location of the know identity of the target, or it can be identified as the area where the known identity enters, as it is indicated by arrow IN in FIG. 2 . In other words, triggering criteria such as “Any phone entering an area” can be used as an alternative or in combination with the report of the geographical coordinates of the known identity to identify the target area subjected to scrutiny with the “Any phone within the area” functionality.
Over a period of time, more spatial surveys are done based on the position of the target. The process is iterative and every time a new MSISDN list is retrieved, it is compared with the previous one, or with the results deriving from previous comparisons of MSISDN lists (S 05 ). In particular, the lists are crosschecked until a single or a very restricted number of MSISDNs is identified (S 06 ). The criteria for ending the iteration can be based on e.g. the identification of a small number of MSISDN, possibly but not limitatively less than two or three unknown identities to be associated to the known identity, or the iteration can be stopped after the same number of identities repeatedly occurs, for a certain number of times, when comparing the lists, or a combination of these criteria, or analogous ones.
A report of the discovered identities, e.g. MSISDN, is delivered in S 07 after which the process stops (S 08 ).
A method according to the preferred embodiment of the invention will now be explained together with FIG. 4 . Signalling points MSC, GMPC, IMDU and LEA have all been shown and briefly explained earlier in FIG. 2 . The method according to the preferred embodiment comprises the following steps:
The IMDU sends out 1 signals to activate the monitoring of the known identity of the target. The IMDU sends out 2 signals to LEA through the Handover Interface to inform that the monitoring of the known identity has been activated. The target T is in a location and brings the registered/known phone/subscription with him, together with any associated unregistered/unknown phone(s)/subscription(s). The GMPC sends out 3 periodical positioning reports to the IMDU. At the first periodical positioning report received by GMPC, the IMDU determines the area where the subscriber is and invokes 4 an “Any phone within the area” request towards the GMPC. The GMPC sends out 5 a first e.g. MSISDN list which is received by the IMDU and stored as data set baseline A. The target T moves around bringing the known subscription with him, together with any associated unknown subscription(s). As the target moves around, the GMPC sends out 6 other periodical positioning reports to the IMDU, and the system continues to invoke other “Any phone within the area” requests 7 . For each new data set B which the GMPC sends out 8 to the IMDU, the system removes those MSISDNs which do not appear in each subsequent set of MSISDNs.
Users located within the target area and reported to the IMDU are those users who are present in the area substantially at the same time when a position of the target is reported within that area.
Eventually, after this iterative process there will be a single or a restricted number of MSISDNs left. At this point, the IMDU stops 9 invoking GMPC and produces an IRI REPORT 10 towards the LEA including all the unveiled target identity(s) C.
As an option, a warrant could be automatically created by IMDU on this newly discovered target identity(s) to facilitate the monitoring.
As it has been mentioned above, the present invention makes use of spatial triggers. A spatial trigger is a feature that allows a Location Services (LCS) client to define spatial criteria. The GMPC monitors the criteria and when it is fulfilled the GMPC reports to the LCS client.
Within the context of the present invention, the following spatial triggers are used:
“Any phone within an area”, and “All phones entering an area”.
The use of spatial triggers is related to the concept of target area, which can be a cell-id (i.e. CGI/SAI), a cell-id list or a shape (defined for example as a circle or a polygon or the like).
A system that can be used to put the invention into practice is schematically shown in the FIGS. 1-4 . Enumerated items are shown in the figure as individual elements. In actual implementations of the invention, however, they may be inseparable components of other electronic devices such as a digital computer. Thus, actions described above may be implemented in software that may be embodied in an article of manufacture that includes a program storage medium. The program storage medium includes data signal embodied in one or more of a carrier wave, a computer disk (magnetic, or optical (e.g., CD or DVD, or both), non-volatile memory, tape, a system memory, and a computer hard drive.
The systems and methods of the present invention may be implemented for example on any of the Third Generation Partnership Project (3GPP), European Telecommunications Standards Institute (ETSI), American National Standards Institute (ANSI) or other standard telecommunication network architecture. Other examples are the Institute of Electrical and Electronics Engineers (IEEE) or The Internet Engineering Task Force (IETF).
The description, for purposes of explanation and not limitation, sets forth specific details, such as particular components, electronic circuitry, techniques, etc., in order to provide an understanding of the present invention. But it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, and techniques, etc., are omitted so as not to obscure the description with unnecessary detail. Individual function blocks are shown in one or more figures. Those skilled in the art will appreciate that functions may be implemented using discrete components or multi-function hardware. Processing functions may be implemented using a programmed microprocessor or general-purpose computer. The invention is not limited to the above described and in the drawings shown embodiments but can be modified within the scope of the enclosed claims. | The present invention relates to methods, nodes, arrangements and articles of manufacture to automatically identify unknown identities of a target. The method comprises the following steps: positioning indicators indicating presence of a known identity of the target in at least one location are periodically collected; —at least one mobile network is interrogated and lists of identities of users located in defined target areas, each area covering at least one of the collected positioning indicators, are fetched; —a crosscheck between the fetched lists is performed; a single or restricted number of identities that is common to the fetched lists is identified. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for plastering construction of an interior wall in architectural decoration.
BACKGROUND OF THE INVENTION
[0002] The existing plastering construction process for architectural decoration generally includes: base treatment; hanging vertically of a plumb; perpendicularity and flatness leveling; line positioning; plaster applying; screed strips constructing on wall surfaces; manual plastering; filling of reserved holes, electric cabinet slots, electric cabinet boxes, and the like; scraping and trowelling; and waste recycling. The above existing construction process has the following disadvantages:
[0003] (1) The traditional process of constructing screed strips on wall surfaces is very demanding for the skills of a plastering worker. In the case of plastering construction by an unskilled worker, the speed of the plaster applying is lowered, and it is difficult to guarantee a high precision of constructing screed strips on the wall surface, resulting in unsatisfying flatness and levelness of wall surfaces and the undesired visual effect of the wall body. Moreover, the screed strip constructing process cannot match with a mechanized construction process, leading to difficulties in significantly improving the construction efficiency.
[0004] (2) During wall surface trowelling after the manual plastering or mechanical mortar spraying, due to the rotary grinding of a wooded trowel, the collision and squeeze occurred within the mortar causes the moisture in the mortar to exude from the mortar. Because of the moisture loss from the mortar to brick bodies of the wall in contact with the mortar, the moisture in the mortar is absorbed prematurely, thus the mortar shrinks and hence the wall surface plumps up, causing phenomena such as cracks in the wall surface and peeling off of the mortar. Moreover, the construction schedule is prolonged since the above processes rely on numerous technical personnel and are time consuming, and the construction efficiency is lowered since the construction processes are fussy and complicated.
SUMMARY OF THE INVENTION
[0005] A technical problem to be solved by the present invention is to provide a method for plastering construction, which improves the efficiency of plastering construction and guarantees high construction quality, without dependency on a technique level of a construction personnel, and may further cooperate with mechanized construction.
[0006] In order to solve the above problems, the present invention provides a method for plastering construction in architectural decoration, including steps of:
(1) base treatment; (2) screed strip constructing; (3) plastering; and (4) wall surface grinding.
[0011] the step (2) of screed strip constructing comprises: positioning alignment wires according to an intended height of applied plaster, and installing longitudinally screed templates along a wall surface treated by the step (1) of base treatment according to a distance between the alignment wire and the wall surface, wherein a transverse interval between the adjacent screed templates is 1.3 m to 1.8 m; and
[0012] the step (4) of wall surface grinding comprises that: the wall surface treated by the step (3) of plastering rests for 12 hours to 24 hours till the plastered mortar on the wall surface is semi-dry and compact and at a solidified state, and the mortar is ground to be flat by saw teeth of a running rule with saw blade abutting against the mortar along two adjacent screed templates.
[0013] The base treatment in step (1) includes: cleaning and drying a wall surface; applying mortar on the wall surface; attaching a stretched fiberglass mesh on the mortar at the time of pre-hardening of the mortar, and pressing the fiberglass mesh into the mortar until the fiberglass mesh is slightly visible; applying mortar on the fiberglass mesh to completely cover the fiberglass mesh; and solidifying the mortar.
[0014] The step (3) of plastering includes a mechanical mortar spraying, which includes: spraying water on the wall surface after the screed scrip constructing; spraying the plastering mortar to the wall surface by a mortar spraying machine till the screed templates are basically covered but slightly visible; scraping the wall surface by a common running rule abutting against the screed templates; and manually repairing and leveling the reserved holes or reserved positions.
[0015] The screed template in the step (2) includes a base configured to be connected with the wall surface, a screed board and a connecting rod for connecting the base with the screed board; the base is provided with an installation through hole for receiving one end of the connecting rod in a direction perpendicular to the base; a side of the screed board, which is close to the wall surface, is provided with a clamping slot configured to perpendicularly receive the other end of the connecting rod along a longitudinal direction, and the screed board is connected with at least two bases via at least the connecting rods.
[0016] The screed templates are installed by: sticking longitudinally the bases on the wall surface by using glue, with the adjacent bases being spaced by an interval of 50 cm; inserting one end of each connecting rod into the installation through hole, shearing the connecting rod to have a length corresponding to a distance between the alignment wire and the wall surface, and pressing the clamping slot after aligning the clamping slot with the other end of the connecting rod.
[0017] The base is integrally formed by a smaller round disc and a bigger round disc which is coaxial with the smaller round disc and configured to connect with the wall surface; the installation through hole is coaxial with the bigger round disc and the smaller round disc; an end of the installation through hole, which is close to the screed board, is provided with a clamping jaw protruding towards the center of the installation through hole.
[0018] Four auxiliary through holes are evenly distributed in a circumferential direction on the bigger round disc; the screed board is integrally formed by a folded plate symmetrically folded about a longitudinal direction and the clamping slot; the clamping slot is disposed on an inner concave surface of a corner of the folded plate and extends along the longitudinal direction; and both lateral sides of the folded plate are respectively provided with a plurality of through holes distributed along the longitudinal direction.
[0019] A plurality of closed annular dents, which are in planes perpendicular to the longitudinal direction of the connecting rod, are evenly distributed on the connecting rod along the longitudinal direction.
[0020] The running rule with saw blade in step (4) includes a saw blade that is provided with the saw teeth along the longitudinal direction and a clamping part connecting with the saw blade.
[0021] A cross-sectional shape of the clamping part is approximate to an isosceles triangle, the clamping part extends at its vertex as two clamping plates for clamping the saw blade, the clamping plates and the saw blade are tightened by a bolt, and the clamping part matches the saw blade in length.
[0022] A length of the saw blade is 1.7 m to 2.3 m; a distance between the saw teeth and a proximal end of the clamping plate is 30 mm to 70 mm; a width of a clamped part of the saw blade is 40 mm to 60 mm; and a width of an end surface of the clamping part, which is away from the saw blade, is 2 cm.
[0023] The screeding apparatus used for the screed strip constructing of the method for the plastering construction in architectural decoration is convenient to install and use, and has a lower technical requirement on the construction personnel, while guaranteeing both the perpendicularity and the flatness of the wall surface and avoiding the dependence on the technical experiences of the construction personnel. Further, the screeding apparatus may be remained inside the wall rather than being taken out from the wall after the screed strip constructing is finished, thereby avoiding repairing at an original position of the screed strip, reducing the working procedures and improving the efficiency. Also, the screeding apparatus may cooperate with a mechanized mortar spraying operation, thereby improving the plastering efficiency. After the mechanized mortar spraying is finished, the existing manual trowelling is avoided, the plastered mortar on the wall surface rests for 12 hours to 24 hours till the plastered mortar on the wall surface is semi-dry and compact and at a solidified state, so that the problem of plumping up of the wall surface can be solved by utilizing the natural solidification of the mortar, and then the mortar is ground by the running rule with saw blade. Compared with the manual troweling, the running rule with saw blade can implement grinding at a larger area and hence is suitable for large-area construction. The running rule with saw blade is simple and convenient in operation, and has a low requirement on a technical merit and a less requirement on the quantity of the construction personnel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.
[0025] FIG. 1 is a front view of a screed template used in a step of screed strip constructing according to the present invention.
[0026] FIG. 2 is a left view of the screed template used in the step of screed strip constructing according to the present invention.
[0027] FIG. 3 is a schematic top sectional view of the screed template used in the step of screed strip constructing according to the present invention.
[0028] FIG. 4 is a front view of a running rule with saw blade used in a step of wall surface grinding according to the present invention.
[0029] FIG. 5 is a left view of the running rule with saw blade used in the step of wall surface grinding according to the present invention.
[0030] FIG. 6 is a bottom view of the running rule with saw blade used in the step of wall surface grinding according to the present invention.
[0031] FIG. 7 is a flow chart of a method for plastering construction in architectural decoration according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] The present invention introduces newly designed tools, i.e. a screed template and a running rule with saw blade. The use of the screed template improves the efficiency of forming screed strips, and lowers requirements for the technique level of the construction personnel, and the use of the running rule with saw blade to grind the wall surface can effectively solve the plumping up of the wall surface, and lower requirements for the technique level and quantity of the construction personnel due to the easy usage of the running rule with saw blade, which has significant meanings on saving labor costs and time costs. FIG. 7 is a flow chart of a method for plastering construction in architectural decoration according to the present invention.
[0033] The method for the plastering construction in architectural decoration according to the present invention includes the following processes of: base treatment, screed strip constructing, mechanical mortar spraying and wall surface grinding.
[0034] In the existing base treatment, a steel mesh for preventing cracking is fixed on the wall by nails, which are covered by plastered mortar. However, both the nails and the steel mesh remained on the wall are likely to rust, which may cause damages to the wall surface. In order to avoid the rust of the nails for fixing the steel mesh, the present invention provides a way of burying a fiberglass mesh by mortar, which can better guarantee that the wall surface after plastering construction is reliable and durable and has thermal insulation and waterproof properties, such that the traditional way of fixing the steel mesh using nails is avoided. In this way, the problem of rust of the nails can be solved, and cracks of the wall surface are prevented.
[0035] The base treatment process in the present invention includes: (1) cleaning and drying a wall surface; (2) applying mortar on the wall surface; (3) attaching a stretched fiberglass mesh on the mortar at the time of pre-hardening of the mortar, and pressing the fiberglass mesh into the mortar until the fiberglass mesh is slightly visible; (4) applying mortar on the fiberglass mesh to completely cover the fiberglass mesh; and (5) solidifying the mortar.
[0036] The fiberglass mesh has good chemical stability and is alkali-resistant, acid-resistant, waterproof, and cement corrosion resistant; has good physical properties such as high strength, high modulus, and light weight; and has good size stability such as rigidness, flatness, good shrinkage and deformation resistance, and excellent positioning property. The fiberglass mesh also has properties of thermal insulation, electrical insulation, and crack resistance. Moreover, a mesh size of the fiberglass mesh may be 5 mm×5 mm and a length of a single fiberglass mesh is generally no more than 6 meters. To join adjacent fiberglass meshes, a width of the overlapping portion of the fiberglass meshes shall be at least 10 cm. To press the fiberglass mesh into the mortar in the step (3), a trowel is used to flatly and firmly press the fiberglass mesh into the surface layer of the mortar from the center of the fiberglass mesh to its periphery. Folds of the pressed fiberglass mesh shall be avoided. The mortar should not be kneaded continuously to avoid the plumping up of the wall surface.
[0037] After the mortar is hardened, the screed strip construction begins.
[0038] As illustrated in FIGS. 1-3 , a screed template used for the screed strip construction includes a base 10 configured to be fixed on a wall surface, a screed board 30 , and a connecting rod 20 for connecting the base 10 with the screed board 30 . The same screed board 30 can connect with at least two bases 10 via at least two connecting rods 20 . Preferably, the base 10 , the screed board 30 and the connecting rod 20 each are integrally made of the recycled plastics so as to save costs and be environment friendly, or made of other materials.
[0039] The base 10 is provided with an installation through hole 11 , in which the connecting rod 20 can be inserted in a direction perpendicular to the base 10 . In order to install the connecting rod 20 on the base 10 more firmly, the base 10 is integrally formed by a smaller round disc 18 and a bigger round disc 17 which is coaxial with the smaller round disc 18 and configured to connect with the wall surface. The installation through hole 11 is coaxial with the bigger round disc 17 and the smaller round disc 18 , and an end of the installation through hole 11 , which is close to the screed board 30 , is provided with a clamping jaw 12 protruding from the wall of the installation through hole 11 towards the center of the installation through hole 11 . As illustrated in FIG. 3 , the clamping jaw 12 is used for fixing the connecting rod 20 perpendicularly to the base 10 . The bigger round disc has a diameter of 60 mm and a height from 1 mm to 2 mm, and the smaller round disc has a diameter of 9 mm and a height of 3 mm. When the screed strip constructing begins, the base 10 is stuck on the wall surface by connecting the bigger round disc 17 with the wall surface. Due to the different conditions of the wall surfaces, the bigger round disc 17 is provided with at least one auxiliary through hole 13 which may have a round shape or other shape, in order to stick the base 10 on the wall surface more firmly. Preferably, a plurality of auxiliary through holes 13 , for example four auxiliary through holes as illustrated in FIG. 2 , are disposed evenly along a circumferential direction in the bigger round disc 17 .
[0040] The screed board 30 is used for indicating the intended height of applied plaster, and a side of the screed board 30 , which is close to the wall surface in use, is provided with a clamping slot 33 configured to perpendicularly receive the connecting rod 20 . The screed board 30 is integrally formed by a folded plate 31 symmetrically folded about a longitudinal direction of the screed board 30 and the clamping slot 33 . The folded plate 31 is bent by an angle of 90 degrees or 60 degrees or other angles. The clamping slot 33 is disposed on an inner concave surface of a corner of the folded plate 31 and extends along the longitudinal direction. In order to prevent the plumping up due to a gap between the clamping slot 33 and the folded plate 31 , both lateral sides of the folded plate 31 are respectively provided with a plurality of through holes 32 evenly distributed along the longitudinal direction. As shown in FIG. 1 and FIG. 2 , the through holes 32 are hexagon-shaped. The mortar can be filled between the clamping slot 33 and the folded plate 31 via the through holes 32 . End surfaces of the folded plate 31 at its both sides, which are close to the base 10 , and an opening end of the clamping slot 33 are in the same plane. The folded plate 31 has a thickness from 1 mm to 2 mm, and has a width from 1 cm to 2 cm.
[0041] A plurality of closed annular dents (i.e. grooves) 21 , which are in planes perpendicular to the longitudinal direction of the connecting rod 20 , are evenly distributed on the connecting rod 20 along the longitudinal direction. As illustrated in FIG. 3 , one end of the connecting rod 20 is perpendicularly inserted into the installation through hole 11 of the base 10 , so that the clamping jaw 12 clamps the dent 21 on the connecting rod 20 to fix the connecting rod 20 , and the other end of the connecting rod 20 is perpendicularly inserted into the clamping slot 33 of the screed board 30 , so that the clamping slot 33 clamps the dent 21 on the connecting rod 20 to fix the connecting rod 20 . For the screed strip constructing, the connecting rod 20 can be sheared to have a desired length depending on the intended thickness of the applied plaster.
[0042] A process of the screed strip constructing includes: positioning alignment wires according to an intended height of applied plaster; sticking the bases 10 on the wall surface applied with the mortar by using glue along a longitudinal direction, with the adjacent bases 10 being spaced by an interval of 50 cm; inserting one end of each connecting rod 20 into the installation through hole 11 , shearing the connecting rod 20 to have a length corresponding to a distance between the alignment wire and the wall surface, and pressing the clamping slot 33 after aligning the clamping slot 33 with the other end of the connecting rod 20 , so that the screed templates are mounted at an interval of 1.3 m to 18 m transversely.
[0043] The screed strip constructing operation of the present invention has a lower technical requirement on the workers, and the screed template has a simple structure and can be easily installed, so that the whole screed strip constructing operation can be finished independently only by the screed templates without needing any other tools or mortar materials. Since the screed templates are close to one another, the height of the applied plaster is easy to adjust and unify, such that the construction efficiency is improved. Thus, the height of the applied plaster will not be negatively affected by techniques of the workers or the deformation of mortar and the screed strips caused by collisions. The base, the connecting rod and the screed board each are integrally formed by the recycled plastics, which not only protects the environment, but also saves the cost without public hazards and pollutions, resulting in public benefit effects of “green building”. The base, the connecting rod and the screed board can be buried in the applied plaster after the plastering is finished, thereby simplifying the process and reducing the construction time. In the prior art, the plastering cannot be implemented until 2 hours after the screed strips have been constructed, while in the present invention, the plastering can be implemented immediately after the screed strip constructing is finished, thereby improving the construction efficiency.
[0044] After the screed strip constructing is finished, next step of plastering is implemented. Either the manual plastering or the mechanical mortar spraying can be employed in the plastering step. The mechanical mortar spraying is implemented in the embodiment of the present invention.
[0045] The process of the mechanical mortar spraying includes: spraying water on the wall surface after the screed scrip constructing; spraying the plastering mortar to the wall surface by a mortar spraying machine till the screed templates are basically covered but slightly visible; scraping the wall surface by a common running rule abutting against the screed templates; and manually repairing and leveling the reserved holes or reserved positions such as an electric cabinet, an electric cabinet slot, an electric cabinet box and the like.
[0046] A mortar spraying machine of a TURBOSOL POLIT type is used for the mechanical mortar spraying in the embodiment. The mortar can be directly applied on the wall surface subjected to the base treatment via the mortar spraying machine, a delivery pipe and a spray nozzle. A thickness of the sprayed mortar is just sufficient to basically cover the screed templates but keep the screed templates be slightly visible. Each time scraping the wall surface by the common running rule abutting against the screed templates, the redundant materials can be recycled. The vacant wall surface can be manually repaired by the workers or repeatedly sprayed by the spraying machine. The above steps may be repeated to guarantee the sufficient mortar spraying. The mortar protruding slightly can achieve a better effect, and vacancy in the wall surface shall be avoided as possible.
[0047] The manual plastering needs for a large number of technical personnel and takes a long construction time, which influences the construction schedule. In addition, the construction process is fussy and complicated, which influences the construction efficiency.
[0048] Compared with the manual plastering, the mechanical mortar spraying greatly improves the efficiency of the mortar spraying and is suitable for the large-area construction, thus a requirement on the quantity of the construction personnel is reduced and the labor cost is saved.
[0049] As a difference from the prior art, a manual trowelling procedure in the plastering operation is cancelled and the step of grinding the wall surface is added in the present invention. The plasticity of the plastered mortar is strong when the plastering is finished because the plastered mortar is in a pre-hardening state. During the manual trowelling process, due to the rotary grinding of a wooded trowel, the collision and squeeze occurred within the mortar causes the moisture in the mortar to exude from the mortar. Because of the moisture loss from the mortar to brick bodies of the wall in contact with the mortar, the moisture in the mortar is absorbed prematurely, thus the mortar shrinks and hence the wall surface plumps up, causing phenomena such as cracks in the wall surface and peeling off of the mortar. Therefore, in the present invention, the plastered mortar on the wall surface rests for 12 hours to 24 hours till the plastered mortar on the wall surface is semi-dry and compact and at a solidified state, so that the problem of plumping up of the wall surface can be solved by utilizing the natural solidification of the mortar, and then the mortar is ground by the running rule with saw blade. Compared with the manual troweling, the running rule with saw blade can implement grinding at a larger area and hence is suitable for large-area construction. The running rule with saw blade is simple and convenient in operation, and has a low requirement on a technical merit and a less requirement on the quantity of the construction personnel, further, the plumping up can be better avoided. The grinding operation can be implemented by either the manual plastering or the mechanical mortar spraying.
[0050] FIGS. 4-6 illustrate structural views of the running rule with saw blade used for grinding the wall surface, and the running rule with saw blade includes a saw blade 300 , a clamping part 200 for clamping the saw blade 300 , and a bolt 100 for fastening the saw blade 300 and the clamping part 200 . Teeth, which may be general teeth, are disposed along the longitudinal direction of the saw blade 300 . The length of the saw blade 300 is 1.7 m to 2.3 m, preferably, 2 m in the embodiment, so as to match with the screed templates arranged at an interval of 1.3 m to 1.8 m. The width of the saw blade 300 is 0.1 m to 0.2 m, and the thickness of the saw blade 300 is 1 mm.
[0051] For ease of the construction, the clamping part 200 is connected to a side of the saw blade 300 , which is opposite to the teeth, and is disposed along the longitudinal direction. Preferably, the length of the clamping part 200 matches with the saw blade 300 . A cross-sectional shape of the clamping part 200 is approximate to an isosceles triangle, the clamping part 200 may be formed by an aluminum alloy plate, and the clamping part extends at its vertex as two clamping plates 210 for clamping the saw blade 300 . The bottom side of the clamping part 200 , that is, an end surface of the clamping part 200 which is away from the saw blade 300 , has a width of 2 cm, so that the clamping part 200 is convenient for griping by a worker. A distance between the teeth of the saw blade 300 and the end of the clamping plate 210 is 30 mm to 70 mm, and a width of a part of the saw blade 300 , which is clamped by the clamping plates 210 , is 40 mm to 60 mm. In the embodiment, the whole width of the saw blade 300 is 0.1 m, a distance between the teeth of the saw blade 300 and a proximal end of the clamping plate 210 is 50 mm, and a width of the part of the saw blade 300 which is clamped is 50 mm.
[0052] To fix the saw blade 300 between the clamping plates 210 of the clamping part 200 , at least two bolts 100 (cooperate with corresponding nuts) are needed for fastening the clamping plates 210 and the saw blade 300 to clamp the saw blade 300 . As illustrated in FIG. 4 , two bolts 100 are respectively disposed at two ends of the clamping part 200 , and one of the two bolts 100 is close to the teeth and the other one is away from the teeth, thereby achieving the fixation purpose.
[0053] A wall surface grinding process is as follows: after the mechanical mortar spraying is finished, the plastered mortar rests for 12 hours to 24 hours till the plastered mortar is semi-dry and compact and at a solidified state, subsequently the construction personnel can grip the clamping part 200 to grind the mortar along two neighboring screed templates from bottom to top, where the teeth abuts against the plastered mortar and the saw blade 300 inclines to the wall surface by an angle in the range from 30 degrees to 60 degrees.
[0054] Upon inspection, both the flatness of the wall surface and perpendicularity at internal and external corners of the wall meet the national standards. Moreover, plumping up, cracks and watermarks do not occur to the wall surface. | A method for plastering construction in architectural decoration comprises the following steps: (1) base treatment; (2) performing construction positioning paying-off according to the required plastering height, and longitudinally installing screeding templates along a wall surface subjected to the base treatment in Step (1) according to the paying-off height, a lateral space between adjacent screeding templates being 1.3 to 1.8 meters; (3) plastering; and (4) laying aside the wall surface subjected to the plastering for 12 to 24 hours till plastering mortar on the wall surface is in a half-dried compact hardened state, and using teeth of a saw blade for grinding the mortar along the two adjacent screeding templates through a ruler till the mortar is even. The method can improve the construction efficiency and guarantee the construction quality. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to a process for forming a metal or metal compound coating on a face of a freshly formed ribbon of hot glass during its travel from a flat glass forming installation, by contacting such face at a coating station with a fluid medium or fluid media comprising a substance or substances from which said coating metal or metal compound is formed on said face.
Processes of the foregoing kind are used for example for forming surface coatings which modify the apparent colour of the glass and/or which confer some other required property in respect of incident radiation, e.g. an infra-red-reflecting property.
In some such processes, the substance(s) from which the required coating is formed is or are supplied in the liquid phase, e.g. by spraying. In other cases the said substance(s) is or are supplied in the vapour phase.
Processes as referred to are particularly useful for forming good quality metal oxide coatings on ribbons of glass during their conveyance from the flat glass forming installation, e.g. a drawing machine or a float tank. The metal oxide coating can be formed by spraying the glass ribbon with a solution of a metal compound from which the metal oxide is formed in situ by chemical reaction or decomposition, e.g. by pyrolysis, on contact with the hot ribbon. A specific example is the formation of a tin oxide coating by spraying a solution of a tin chloride, with or without other ingredients. Alternatively a said metal oxide coating can be formed by contacting the hot ribbon with a stream of a vaporised metal compound e.g. a vaporised tin compound, and a stream of oxygen or oxygen-containing gas to cause an oxidation reaction with formation of the required metal oxide coating on the ribbon. Processes as referred to can however also be used for forming coatings of other metal compounds, e.g. for forming a coating of a metallic boride, sulphide, nitride, carbide or arsenide by reacting a corresponding metallic or organometallic compound with a halogenated boron compound, H 2 S, NH 3 , CH 4 , or an arsenic containing compound, in the absence of oxygen. Metal coatings can be formed by contacting the glass ribbon in a reducing atmosphere or at least in the absence of oxygen, with a metal carbonyl, e.g. nickel carbonyl, which decomposes under the action of heat provided by the hot ribbon.
It is not easy to form coatings satisfying the high quality standards which the market sometimes demands. One important problem which is encountered is that of controlling the thickness of the coating so that it complies with given standards. The thickness of the coating forming on any region within the area of the glass ribbon is susceptible of the influence of various factors. These include not only the rate at which the fluid coating medium or media is or are supplied to the coating station but also the temperature conditions at that station. The temperature conditions of the glass at the coating station are of course determined primarily by the temperature to which the glass is heated in the flat glass forming installation, which in turn depends on the nature of that installation and the required specifications of the ribbon.
The temperature of the glass at the coating station is liable to vary in course of time and from one part of the ribbon to another. Such temperature differences may occur for example because of a change being effected in the thickness and/or speed of the glass ribbon, or because of the influence of convection currents circulating above and around the glass ribbon. Differences in glass ribbon temperature in course of time or across the ribbon can to some extent be compensated for by modifying the temperature at which the fluid coating medium or media is or are fed to the coating station, but it is not always convenient and in some cases it is not possible for the coating thickness to be influenced quickly enough or to the required extent in that way.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a coating process wherein the temperature of the glass ribbon is influenced in a convenient manner and in a way which assists formation of a coating of the required thickness.
According to the present invention there is provided a process for forming a metal or metal compound coating on a face of a freshly formed ribbon of hot glass during its travel from a flat glass forming installation, by contacting such face at a coating station with a fluid medium or fluid media comprising a substance or substances from which said coating metal or metal compound is formed on said face, characterised in that preparatory to being coated the glass is thermally conditioned at a thermal conditioning station between the flat glass forming installation and the coating station, so as to eliminate or reduce temperature gradients across the ribbon width to be coated.
The "ribbon width to be coated" can be the full width of the ribbon or a lesser width, e.g. a central portion of the ribbon width between two marginal strips which are left uncoated.
The reduction or elimination of temperature gradients across the glass ribbon at the thermal conditioning station has the indirect effect of reducing or avoiding variations in the coating thickness transversely of the ribbon.
The temperature of the glass ribbon usually varies across the ribbon width. The side marginal regions of the ribbon tend to cool more quickly than the medial part of its width, with the consequence that the thickness of the coating formed at the coating station tends to increase or decrease from the side margins of the ribbon towards its longitudinal centre line, depending on the type of coating compositions employed.
Accordingly, in some embodiments of the invention, the thermal conditioning to which the ribbon is subjected is such as to cool the medial part of its width to or towards the temperature of the side marginal regions of the width to the coated. Alternatively, heat radiating from such medial part may be reflected back to the side regions to reduce the heat loss at those side regions.
It is however preferred that said conditioning station be constituted as a heating station which is controlled so that one or more portions of the ribbon width is or are selectively or differentially heated. This has the advantage of allowing greater latitude in the choice of location for the coating and thermal conditioning stations in particulat so that if a high ribbon temperature is required for the coating operation in view, those stations need not be located inconveniently close to the ribbon forming installation itself.
When carrying out the invention, the heat supply distribution at the heating station can be such that each portion of the ribbon width to be coated has on arrival at the coating station a temperature condition which is appropriate for the formation of a coating of the required thickness under the conditions prevailing at that coating station. The heating affords a convenient control facility whereby the thickness of the coating formed on the glass ribbon can be controlled, if required over the whole transverse extent of the coating. The temperature control is exercisable without affecting the conditions under which the glass ribbon is formed. The process according to the invention can e.g. be performed in float glass production plant and in sheet glass production plant using a glass drawing machine of the Libbey-Owens type.
In certain processes according to the invention, the heat is supplied at the heating station so as only to heat marginal portions of the ribbon width to be coated. In consequence the glass is brought to a uniform or more uniform temperature across the width of the ribbon preparatory to coating and substantially without affecting the coating thickness in the central portion of the ribbon width.
In other processes according to the invention, heat is supplied at the heating station so that the whole of the ribbon width to be coated is heated but to an extent which varies transversely of the ribbon. In such processes the heating both avoids or reduces coating thickness variations transversely of the ribbon, and alters the mean thickness of the coating.
Advantageously, heat is supplied to the glass at the heating station wholly or mainly from one or more radiant heaters. For example the glass may be heated at the heating station by radiant heaters having a black body temperature in excess of 1000° C. Preferably one or more gas-fired radiant heaters is or are employed. However, radiant heaters of electrical resistance type can be used. Alternatively use can be made of combustible fuel burners. Heat reflectors can be provided for directing the radiant heat towards the glass ribbon.
In certain embodiments of the invention heat is supplied to the glass at the heating station wholly or mainly by feeding pre-heated gas from an extraneous source into the environment above the ribbon. That mode of heating affords the advantage that it avoids the need to provide and service heaters in the vicinity of the glass ribbon path. The pre-heated gas can be discharged into the environment over the ribbon from different orifices or from different series of orifices located respectively over the different portions of the ribbon to be heated.
A combination of different kinds of heating may be employed for heating the glass ribbon at the heating station. For example radiant heaters can be used in conjunction with the supply of pre-heated gas into the environment above the ribbon.
Preferably, a transverse screening wall is provided above the ribbon path, between the coating and thermal conditioning stations. Such a screening wall, serving as a kind of downstream boundary to the thermal conditioning station (the downstream direction being the direction of travel of the glass ribbon), facilitates attainment of a predetermined selective or differential thermal conditioning of the glass ribbon at the thermal conditioning station.
It is convenient for the coating station to be located in a tunnel along which the glass ribbon travels from the flat glass forming installation. Such tunnel may for example be the annealing lehr conventionally employed in many flat-glass forming plants. Said transverse screening wall as above referred to can conveniently extend transversely across the upper part of the tunnel, between its side walls. It is most convenient if both the coating station and the thermal conditioning station are located in a said tunnel.
The invention includes processes in which the glass ribbon is heated at the thermal conditioning station by heat supplied from within a compartment located above the path of the ribbon, to the interior of which compartment the glass ribbon is exposed, such compartment having upstream and downstream boundary walls whose lower edges are spaced from the ribbon. A said compartment (hereafter called "temperature control compartment") can be formed quite easily by providing transverse screens within a tunnel as above referred to, so as to serve as the upstream and downstream boundary walls of the compartment. The provision of both downstream and upstream boundary walls to the thermal conditioning station further facilitates heating portions of the glass ribbon in a required selective or differential manner preparatory to passage of the glass through the coating station. One or more partition walls can be provided for partitioning the temperature control compartment into side by side sections for further promoting selective or differential thermal conditioning of portions of the ribbon width.
In certain embodiments of the invention, the heating of the glass at the thermal conditioning station is achieved wholly or mainly by feeding pre-heated gas from an extraneous source into a temperature control compartment as above referred to.
The supply of hot gas into a temperature control compartment as above described can afford important secondary advantages if the ribbon is coated in a tunnel which is in closed communication with the flat glass forming apparatus, as it is for example in a conventional Libbey-Owens type flat glass forming plant. During investigation of the causes of irregularities and defects which sometimes occur in coatings formed in the tunnel, it has been found that the natural draught currents within the tunnel can be a contributory cause of such defects. Currents of hot gas from the glass forming installation travel forwardly along the tunnel above the glass ribbon and a return cooler gas current flows back beneath the ribbon, towards the forming installation. Such natural draught currents are subject to unpredictable variations of various magnitudes, depending on the plant design. It is not possible to prevent flow of gases along the tunnel, through the coating station, without creating a very adverse pattern of gas currents and temperature gradients within the tunnel as a consequence of the partial vacuum effect.
In certain processes according to the present invention the glass ribbon is heated prior to being coated, by the action of hot gas fed into a temperature control compartment as above specified, and the feed rate of the hot gas into said compartment is sufficient to maintain a continuous upstream and downstream flow of gas from said compartment via the slots between the glass ribbon and the upstream and downstream boundary walls of the compartment.
The maintenance of escape flows of hot gas from a temperature control compartment as above specified is beneficial for achieving the best temperature control effects. Moreover if the coating process is performed in the annealing tunnel of a flat glass drawing plant the escape current of gas in the upstream direction constitutes a barrier to the natural draught currents from the sheet glass drawing machine and prevents the environment in the coating station being affected by the direct action of such natural draught currents. The normal flow of environmental gas to the coating station from the drawing machine is replaced by a flow of hot gas from the temperature control compartment. The interception of the said natural draught currents affords the further advantage of avoiding or reducing the deposition of dust on the glass ribbon during its travel further downstream along the tunnel.
In certain embodiments of the invention the hot gas is fed into a said temperature control compartment in a direction which is inclined downwardly towards the upstream gas escape slot. Provided that the upstream gas escape slot is not too wide, this directional deliverly of gas into the compartment affords the advantage that, other things being equal, a lower volume rate of feed of hot gas into the compartment will suffice for maintaining a required exit flow of gas from the compartment.
The height of the escape slots between the upstream and downstream boundary walls of the temperature control compartment and the ribbon influences the rate at which hot gas must be fed into the compartment in order to maintain an upstream escape flow of the hot gas.
Preferably the height of the upstream gas escape slot, (i.e. the distance between the glass ribbon and the bottom edge of the upstream boundary wall of the temperature control compartment) is less than 40 mm. Extensive tests have shown that there are very important benefits to be gained by keeping the width of the upstream escape slot below 40 mm. One very important advantage is that of keeping the consumption of pre-heated gas for feeding the temperature control compartment within limits which are in ordinary circumstances economically acceptable. In the most important embodiments of the invention, the height of the upstream gas escape slot is less than 20 mm.
The height of the downstream gas escape slot is also a factor influencing the minimum volume rate at which hot gas must be fed into the temperature control compartment in order to maintain an escape flow of the gas in the upstream direction, towards a drawing machine. Preferably the downstream escape slot is also less than 40 mm in height. Processes which have been found to have the highest efficiency, assessed in terms of the effectiveness of a given hot gas consumption for countering disruptive currents in the coating station, are those wherein each of the upstream and downstream escape slots is less than 20 mm in height.
When coating the glass at a coating station located in a tunnel along which the glass ribbon travels away from the flat glass forming installation it is advantageous to provide at least one transverse screen in the tunnel beneath the path of the glass ribbon and near the entrance to the tunnel. Such a bottom screen can restrict the magnitude of relatively cool return gas currents flowing upstream, beneath the glass ribbon, towards the glass forming installation and consequently can further reduce the risk of dust deposition on the glass ribbon. It has been found that the volume rate at which hot gas must be fed into a temperature control compartment in order to counter disruptive convection currents in the coating station is less if such a bottom screen is provided. Preferably a said bottom screen is provided at a position beneath a temperature control compartment above referred to. The said disruptive convection currents can be even more easily countered if two such bottom screens are provided at positions spaced along the path of the return gas currents, near the entrance to the tunnel. Generally it is very satisfactory for the two bottom screens to be located at regions beneath the upstream and downstream boundary walls of a said temperature control compartment.
The invention includes processes wherein the conditioning of the glass ribbon at the thermal conditioning station is automatically controlled in dependence on signals emitted by a device which detects thickness values of the coating on the glass ribbon at a detecting station located downstream from the coating station. For example the coating thickness is assessed by determining the laser beam reflecting property of the coating. Alternative available methods of determining coating thickness are for example those which measure the retrodiffusion of β-rays or which measure the reflection or transmission of light rays by means of a spectrophotometer, and methods using an X-ray fluorescing detector based on interferometry or scanning microscope techniques.
The coating can be formed from a coating precursor compound which is sprayed in solution onto the glass ribbon. The droplets of solution can be discharged in a stream or streams whose impingement zone or combined impingement zones on the ribbon cover(s) the entire width of the substrate area to be coated. In that case the source or sources of the droplet stream(s) can be stationary. Alternatively one or more streams of droplets can be discharged from one or more spraying devices which is or are repeatedly displaced to and fro transversely of the glass ribbon path so that the stream(s) travel over the full width of the substrate area to be coated.
In certain very advantageous embodiments of the invention the coating is formed from a coating precursor compound which is sprayed in solution onto the glass ribbon, the spray droplets forming at least one stream which is inclined downwardly towards the ribbon in the direction of its movement or in the reverse direction. This procedure promotes steady conditions at the impingement zone(s) of the droplet stream(s) on the glass ribbon.
The invention includes such a coating process wherein at least one jet of pre-heated gas is discharged, in the same direction, from an orifice or orifices and such gas jet(s) influences the temperature of spray droplets on their way to the glass ribbon. The use of one or more pre-heated gas jets in that way also has the effect of further influencing the coating thickness. Consequently this thickness can be adjusted more quickly and over a wider range if such (a) jet(s) is or are used in combination with heating of the glass ribbon at the heating station in accordance with the present invention.
A coating process wherein use is made of one or more droplet streams which is or are downwardly inclined in that way and wherein one or more jets of pre-heated gas is or are used for influencing the temperature of the droplets on their way to the substrate being coated is described and claimed in our British Patent Application No. 8003357 filed on Jan. 31, 1980, and in our U.S. patent application Ser. No. 228,235 filed on Jan. 26, 1981 which claims priority therefrom.
When spraying a liquid medium, the spray is preferably downwardly inclined, in the direction of travel of the glass ribbon or in the opposite direction, so that the included angle between the axis of the droplet stream and the glass ribbon is in the range 20° to 60° and most preferably in the range 25° to 35°. This feature facilitates the formation of coatings of good optical quality. For obtaining the best results all parts of the spray should be incident upon the ribbon at a substantial inclination to the vertical. Accordingly, in the most preferred embodiments of the invention the spray comprises a parallel stream of droplets or one which diverges from its source at an angle of not more than 30°, e.g. an angle of about 20°.
Experiments indicate that uniform coatings can be more easily formed if certain conditions are observed with respect to the distance between the glass ribbon and the source of the spray. Preferably such distance, measured normally to the ribbon, is from 15 to 35 cm. This has been found to be the most suitable range, particularly when observing the preferred inclination and divergency ranges for the spray above referred to.
When using a spray coating technique, it is preferable to perform the coating process while suction forces are created in exhaust ducting whose entrance is located downstream from the droplet stream(s) by which suction forces gases environmental to said stream(s) are caused continuously to flow in the downstream direction away from said stream(s) and directly into said ducting. Such suction forces are of course controlled so that they do not disrupt the spray or render it unsteady. Such processes combine performance of the present invention and the invention which is the subject of U.K. Pat. No. 1 523 991.
The exhaust ducting may comprise at least one exhaust duct having an entrance which extends transversely across the path of the glass ribbon over the width (i.e. the transverse dimension) of the ribbon area being coated. Such entrance may be in the form of a single slot or may comprise a series of inlet orifices distributed across the path of the glass ribbon.
Advantageously the exhaust ducting comprises at least one said exhaust duct which forms or is associated with a mechanical barrier located so as to prevent gases from passing over said duct, towards and into contact with the exhaust gas currents flowing towards the exhaust ducting from the action zone of the droplet stream(s). This particular feature characterises a coating process described and claimed in our British Patent Application No. 8003358 filed Jan. 31, 1980 and in our U.S. patent application Ser. No. 228,234 filed Jan. 26, 1981 which claims priority therefrom.
In the most preferred embodiments of the invention there is a said exhaust duct at each of two or more positions spaced one behind the other in the direction of displacement of the glass ribbon and a said mechanical barrier is formed or is associated with at least the last one of those ducts reckoning in the downstream direction.
A process according to the invention can be applied for forming various oxide coatings by employing a liquid composition containing a metal salt. Very advantageous processes according to the invention include processes wherein the sprayed material is a solution of a metal chloride from which a metal oxide coating forms on the glass ribbon. In some such processes the said solution is a tin chloride solution, e.g. an aqueous or non-aqueous medium containing stannic chloride and a doping agent, e.g. a substance providing ions of antimony, arsenic or fluorine. The metal salt can be employed together with a reducing agent, e.g. phenyl hydrazine, formaldehyde, alcohols and noncarbonaceous reducing agents such as hydroxylamine, and hydrogen. Other tin salts may be used in place of or in addition to stannic chloride, e.g., tin dibutyl diacetate, stannous oxalate, stannous bromide, and nitrates. Examples of other metal oxide coatings which can be formed in a similar manner include oxides of cadmium, magnesium and tungsten. For forming such coatings the coating composition can likewise be prepared by forming an aqueous or organic solution of a compound of the metal and a reducing agent. As a further example the invention can be employed for forming coatings by pyrolysis of organo-metallic compounds, e.g. a metal acetylacetonate, supplied in droplet form to the substrate face to be coated. It is within the scope of the invention to apply a composition containing salts of different metals so as to form a metal coating containing a mixture of oxides of different metals.
A process according to the invention can also be applied for forming coatings by contacting the heated glass ribbon with a gaseous medium. The gaseous medium may comprise one or more substances in gaseous phase which undergo(es) chemical reaction or decomposition to form the required metal or metal compound coating on the glass. Metal oxide coatings can for example be formed by contacting the hot glass ribbon with a stream of oxygen or oxygen-containing gas and a separate stream of a vaporised metal compound with which oxygen reacts to form a metal oxide coating. Various metal oxide coatings can be formed in that matter. For example a tin oxide coating can be formed from a vaporised tin compound and a stream of oxygen-containing gas, and a titanium dioxide coating can be formed using streams of titanium tetrachloride and oxygen. The vaporised metal compound will usually be diluted with an inert gas e.g. nitrogen and the vapour stream may contain additional ingredients for modifying the properties of the coating. Coatings of other metal compounds can likewise be formed from the vapour phase, e.g. a coating of metallic boride, sulphide, nitride, carbide or arsenide by reacting a corresponding metallic or organometallic compound with a halogenated boron compound or with H 2 S, NH 3 , CH 4 or an arsenic containing compound, in the absence of oxygen. Also metal coatings can be formed. For example, a coating of nickel can be formed by decomposing nickel carbonyl under the action of heat provided by the heated glass ribbon, in a reducing atmosphere or at least in the absence of oxygen.
When forming a coating from the gaseous phase, it is advantageous to cause the gaseous medium to flow along the glass ribbon as a substantially turbulence-free layer as described and claimed in United Kingdom Pat. No. 1 524 326.
The invention includes apparatus suitable for use in coating a freshly formed ribbon of hot glass during its travel from a flat glass forming installation, said apparatus comprising means for delivering (a) fluid coating medium or media into contact with the glass at a coating station, characterised in that there is means whereby the temperature of one or more portions of the ribbon width can be conditioned selectively or differentially at a thermal conditioning station located between the flat glass forming installation and said coating station, so as to eliminate or reduce temperature gradients across the ribbon width to be coated.
The advantage of this apparatus and of the specific optional features hereafter referred to will be apparent from what is written earlier in this specification concerning the coating process and the preferred embodiments thereof.
Said thermal conditioning station is preferably constituted as a heating station incorporating heating means.
In some embodiments of the invention, the heating means is arranged for heating only opposed marginal portions of the ribbon width to be coated.
In other embodiments, the heating means is arranged for heating the whole of the ribbon width to be coated, but to an extent which varies transversely of the ribbon.
Preferably the apparatus comprises regulating means whereby the heat supply distribution across the glass ribbon path at the heating station can be varied.
In certain apparatus according to the invention said heating means comprises one or more radiant heaters. Such radiant heaters are suitably of gas-fired type, but electrical resistance radiators can be used. The radiator or radiators may be associated with one or more heat reflectors for directing heat downwardly towards the glass ribbon.
The invention includes apparatus as above defined wherein the heating means is constructed for heating the glass wholly or mainly by feeding pre-heated gas from an extraneous source into the environment above the glass ribbon at the heating station. Advantageously said means comprises ducting having gas discharge orifices over at least certain portions of the ribbon path through the heating station. In preferred embodiments the heating means is arranged so that streams of gas at different temperatures can be supplied to different discharge orifices.
In certain apparatus according to the invention there is a transverse screening wall above the glass ribbon path, between the thermal conditioning and coating stations.
Preferably the coating station is located within a tunnel along which the ribbon travels from the flat glass forming installation. And most preferably both the thermal conditioning and the coating station are located in such tunnel. One or more screens may be provided beneath the path of the glass ribbon through the tunnel, near the tunnel entrance, in order to reduce the magnitude of return convection currents along the tunnel.
The invention includes apparatus as above defined wherein the heating means is arranged to supply heat to the glass ribbon from within a compartment (herein called "temperature control compartment") which is located above the glass ribbon path and the interior of which is exposed to such path, such compartment having upstream and downstream boundary walls whose lower edges are spaced from such ribbon path.
Preferably there is or are one or more partition walls within said temperature control compartment whereby the compartment is divided into side by side sections, such partition wall(s) serving to concentrate the action of the heating means on particular portions of the ribbon width to be coated.
In certain apparatus according to the invention, the heating means comprises gas discharge ducting arranged for discharging pre-heated gas into a said temperature control compartment from an extraneous source. Advantageously said gas discharge ducting is arranged for discharging pre-heated gas into said temperature control compartment in a direction which is inclined downwardly towards the slot between the upstream boundary wall of such compartment and the path of the glass ribbon.
Preferably the lower edge of each of the upstream and downstream boundary walls of the temperature control compartment is at a distance of less than 40 mm from the path of the glass ribbon.
The apparatus preferably incorporates means for determining the thickness of the coating on the moving glass ribbon and for emitting signals which automatically control the supply of heat to the glass at the heating station. The detecting means may for example assess the thickness of the coating by determining its laser beam reflecting property.
A coating apparatus according to the invention can be used for coating a continuous ribbon of float glass or drawn glass.
The means for delivering fluid medium into contact with the glass at the coating station may comprise one or more spraying devices. Such device(s) may be driven so as repeatedly to traverse the glass ribbon path in to and fro motion. Preferably the spraying device(s) is or are arranged for spraying material at a downward inclination towards the ribbon path, in the direction in which the ribbon is conveyed through the lehr or in the opposite direction.
The means for delivering fluid medium into contact with the glass at the coating station may alternatively comprise means for delivering a said medium in the gaseous phase.
BRIEF DESCRIPTION OF THE DRAWING
Reference will now be made to the accompanying diagrammatic drawings which illustrate certain apparatus according to the invention, selected merely by way of example. The drawings comprise FIGS. 1 and 2 each of which shows in sectional elevation part of a flat glass forming plant incorporating a coating apparatus according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows part of a tunnel 1, which is in this instance an annealing lehr, having refractory roof and sole walls 2, 3 along which a ribbon 4 of float glass travels from a float tank (not shown) in the direction of arrow 5. The glass ribbon is supported in the lehr by supporting rollers 6.
At a coating station with the lehr a spray gun 7 is reciprocated to and fro transversely across the ribbon path. The spray gun is fed with coating solution and compressed air via conduits such as 8 supported within a carriage 9 which travels along a track formed by rails 10 mounted on the roof wall of the lehr. The carriage, with the spray gun, is reciprocated by a mechanism (not shown) over a distance and at a speed such that a continuous coating is formed on the full width of the glass ribbon as it travels through the lehr.
Upstream from the coating station there is a temperature control compartment 11. The compartment is formed within the lehr by providing spaced refractory screens 12, 13 which extend transversely across the lehr above the path of the glass ribbon. These screens form the upstream and downstream boundary walls of the compartment. Their lower edges are spaced from the ribbon path. Within the compartment there are radiant heaters such as 14, 15 of gas-fired type arranged in two rows extending transversely across the ribbon path. Radiant heat reflectors 16 are associated with the heaters for reflecting radiant energy downwardly onto the glass ribbon. Control means is provided whereby the fuel supply to different heaters in each row can be independently varied so that the glass ribbon can be heated to an extent which varies across its width. This fuel control means operates in dependence on signals from a coating thickness detector which senses the laser beam reflecting property of the coating at various positions across the ribbon at a detecting station located further downstream.
The temperature of the ribbon as it enters the annealing lehr is lower near the side edges of the ribbon than at its centre. In these circumstances the fuel supply to the rows of heaters 14, 15 is controlled so that heat is radiated only or mainly towards the marginal portions of the glass ribbon. The disparity in temperature between the marginal zones and the central zone of the ribbon can thereby be eliminated or appreciably reduced.
The apparatus can be modified, within the scope of the invention, by providing heaters only over opposed marginal portions of the path of the glass ribbon, and/or by using electrical resistance instead of gas-fired heaters.
In some plant, the difference in temperature between the margins and central portion of the glass ribbon may be large, e.g. from 20° to 30° C. If the heating of the ribbon where it passes beneath the temperature control compartment 11 does not sufficiently reduce the temperature gradients across the ribbon, residual temperature gradients can be wholly or partly compensated for by modifying the temperature of the coating solution spray to an extent which varies during each traverse of the spray across the path of the ribbon. For this purpose ducting 17 as indicated in broken line can be provided which has discharge orifices distributed across the lehr behind the path of reciprocation of the spray and jets of pre-heated gas can be discharged from those orifices towards the spray as suggested by arrow 18. The gas jets affect the temperature of the droplets encountered by the jets, and consequently the thickness of the coating which forms on the glass ribbon from such droplets. In order to compensate for the residual temperature gradients across the ribbon as above referred to, the gas jets discharged from ducting 17 should generally act on the spray droplets only or primarily during movement of the spray across the central portion of the ribbon width or across the marginal portions thereof.
The temperature of the gas jets may for example be such as to promote evaporation of solvent from or mainly from the droplets travelling towards the marginal portions of the ribbon in order to promote formation of a thicker coating on such ribbon portions. But it is to be noted that in some cases, depending on the nature of the coating precursor material, heating of droplets may reduce rather than increase the coating thickness.
By acting on droplets of coating material by gas jets of controlled temperature, it is also possible to compensate or partly compensate for the decelerations of the spraying device which normally occur towards the ends of its traverse across the tunnel in the event that the spraying device is driven in to and fro motion.
The action of jets of pre-heated gas on droplets of a sprayed coating solution as above referred to is described and claimed in U.S. patent application Ser. No. 228,235 filed Jan. 26, 1981. The same jets, or additional gas jets, can be directed so as to contribute to some extent to an improvement in the quality of the coating by intercepting or diluting reaction products which may contaminate the environment behind the spray and be entrained downwardly into contact with the glass immediately before it is coated. Such action is described and claimed in British patent application No. 8003359 filed Jan. 31, 1980, and in U.S. patent application Ser. No. 228,233 filed Jan. 26, 1981 which claims priority therefrom.
The gas jets from ducting 17, like the heaters 14, 15 in the compartment 11, can be controlled automatically in dependence on signals emitted by a coating thickness detector.
Downstream from the coating station there are exhaust ducts 19 which extend across the lehr and are connected to means (not shown) for maintaining suction forces in those ducts. The object of this exhaust system is to cause gases in the environment of the spray to be aspirated downstream away from the path of reciprocation of the spray and into the entry nozzles 20 of the exhaust ducts, as suggested by the broken lines 21, and thereby reduce the risk of spurious surface deposits on the formed coating. The suction forces are adjusted so that the trajectories of the droplets from the spray gun are substantially unaffected and the process is therefore in accordance with the invention described in United Kingdom patent No. 1 523 991.
FIG. 2 of the accompanying drawings shows part of a sheet glass drawing plant of Libbey-Owens type comprising a drawing compartment 22 in which a ribbon of glass 23 is drawn upwardly from a bath (not shown) of molten glass and passes over a bending roll 24. The glass ribbon travels from this bending roll along a tunnel 25 (which is an annealing lehr) having refractory roof and sole walls 26 and 27. The ribbon is supported within the lehr by rollers 28.
Spray guns 29 and 30 are mounted in the lehr above the horizontal path of the glass ribbon and are connected to mechanisms (not shown) for displacing them to and fro along horizontal paths normal to the direction of travel of the glass ribbon. The spray guns are used for spraying material towards the ribbon to form superimposed metal oxide coatings on the glass.
Upstream from the coating zone, i.e. between the coating zone and the entrance to the lehr, there is a temperature control compartment 31 formed by providing refractory screens 32 and 33 (e.g. asbestos screens) which extend transversely across the lehr, above the path of the glass ribbon. The lower edges of these screens are spaced from the ribbon so that between such screens and the ribbon there are slots 34 and 35 via which gas can flow from the temperature control compartment in the upstream and the downstream directions. Within the temperature control compartment there is a row of axially aligned delivery ducts 36, which extends transversely across the lehr. The individual ducts are connected to an air pump (not shown) located externally of the lehr. The air delivered to the ducts 36 is preheated by heat exchangers (not shown). The temperatures of the heat exchangers are independently regulatable for controlling the temperature of the air supplied to the individual ducts. Each of the ducts 36 has a series of downwardly facing discharge orifices so that hot air pumped into the duct discharges downwardly as indicated by the arrow 37. The hot air heats the glass ribbon selectively or differentially across its width in order to promote formation of a coating of uniform or more uniform thickness. The feed rate and/or the temperature of the gas supplied to the ducts 36 can be varied at any time should this be required, e.g. for the purpose of varying the coating thickness or adjusting the coating process to suit a different drawing speed in the drawing compartment 22.
The flow rate and/or the temperature of the gas supplied to the plurality of ducts 36 as the case may be, can be controlled automatically in dependence on signals emitted by a coating thickness detector as described in connection with the apparatus shown in FIG. 1.
Preferably the hot air is fed into the compartment 31 at a volume rate sufficient to maintain escape flows of this air through slots 34 and 35 and prevent the sprays from the spray guns 29 and 30 from being adversely affected by downstream draught currents of gas through the coating zone from the drawing compartment 22.
Downstream from the coating zone there are exhaust ducts 38, 39 and 40 extending transversely across the lehr above the ribbon path. These ducts form part of an exhaust system in which suction forces are maintained for the purpose of drawing off gases in a downstream direction away from the coating zone. Such aspiration of environmental gases from the coating zone is helpful in preventing reaction products which may be formed in the environment of the coating zone from precipitating onto the glass.
Beneath the ribbon path through the lehr there is a refractory screen 42 located near the entry end of the lehr. This bottom screen serves to restrict the flow of relatively cool return gas currents beneath the ribbon path and into the drawing compartment. This has the advantage of reducing liability for entrained dust to become deposited on the glass ribbon.
In a modification of the plant shown in FIG. 2 the feed of pre-heated air into the temperature control compartment 31 takes place via discharge orifices located so that the pre-heated air discharging from the ducts 36 is directed at a downward inclination towards the upstream escape slot 34 as suggested by arrow 44.
As hereinbefore described the direction of the heating gas in that way enables draught currents from the drawing compartment to be countered more easily, provided that the screen 32 is not too high. The apparatus can also be modified by providing a second refractory screen 45, as shown in broken line, adjacent screen 42. Screen 45 supplements the action of screen 42 in restricting the return flow of gas into the drawing compartment from beneath the ribbon path and can therefore further reduce dust deposition on the glass.
Yet a further possible modification of the plant shown in FIG. 2 is the provision of a partition wall 46 shown in broken line, in association with the exhaust duct 40. This wall extends transversely across the lehr, between the duct 40 and the roof wall 26 of the lehr, and serves to prevent gas currents flowing beneath that exhaust duct from being drawn back over that duct towards the coating zone.
The invention can also be carried out by supplying coating material to the hot glass ribbon in the vapour phase. For example such a process can be performed in apparatus as shown in FIG. 1 with the modification that the spraying device is replaced by a conduit through which vaporised coating precursor compound in a carrier gas stream can be supplied to the coating station and there discharged into the entry end of a shallow flow passage defined by the glass ribbon and a hood which bridges the path of the glass ribbon. Residual vapour leaving the downstream end of the flow passage can be drawn off via a chimney or other exhaust system. The arrangement of the vapour feed conduit and flow passage at the coating station can e.g. be as described and illustrated in United Kingdom patent No. 1 524 326. When forming a coating from the vapour phase the supply of heat at the heating station serves the same function of reducing or avoiding temperature gradients across the ribbon in order to assist the formation of a coating having required specifications.
The following are examples of processes according to the invention:
EXAMPLE 1
A ribbon of float glass having a width of about 2.5 meters and travelling from the float tank at a speed of 4.5 meters per minute, was coated by means of a coating apparatus as represented in FIG. 1.
The temperature of the glass as it approached the heating compartment 11 was 580° C. at the central region of the ribbon and 560° adjacent the edges of the ribbon.
Gas-fired radiant heaters 14 and 15 located above each marginal region of the ribbon were energised so as to heat the said marginal regions of the ribbon and thereby flatten the temperature gradient across the ribbon. The said marginal regions of the ribbon were in fact heated to a temperature very close to 580° C.
The spray gun 7 was of conventional type. The gun was mounted 25 cm above the glass ribbon and was pointed at an inclination of 30° to the ribbon plane. The gun was reciprocated at 10 cycles per minute along a path which extended slightly beyond the edges of the ribbon so that the speed of the spray gun was substantially constant over substantially the full width of the ribbon. The gun was fed under a pressure of about 3 kg/cm 2 with about 50 liters per hour of a solution obtained by dissolving in dimethylformamide, per liter, 140 g of cobalt acetylacetonate Co(C 5 H 7 O 2 ) 2H 2 O.
Suction forces were maintained in the exhaust ducts 19 to cause gases to be aspirated downstream from the coating station but without affecting the trajectories of the droplets from the spray gun.
The rate of discharge of the coating solution was adjusted so that a coating of cobalt oxide (Co 3 O 4 ) having a thickness of about 920 A formed on the glass.
The coating, which had a brown tint viewed by transmitted light, was found to be of good optical quality and of substantially uniform thickness across the full width of the ribbon.
In a modification of the foregoing process, a cobalt oxide coating was formed on the float glass under the same conditions as before except that pre-heated gas was continuously discharged through ducting 17 as represented in broken line in FIG. 1. This had the effect of modifying the temperature conditions of the atmosphere through which the droplets travelled towards the glass ribbon with the result that the thickness of the coating was of an even higher standard of uniformity over the width of the ribbon. The temperature of the air dicharged through ducting 17 can be controlled so as to compensate for the effects of any decelerations of the spray gun near the ends of its path of reciprocation.
EXAMPLE 2
A ribbon of float glass having a width of about 2.5 meters and travelling from the float tank at a speed of 4.5 meters per minute, was coated by means of a coating apparatus as represented in FIG. 1, without ducting 17.
The temperature of the glass as it approached the heating compartment 11 was 580° C. at the central region of the ribbon and 560° adjacent the edges of the ribbon.
All of the gas-fired radiant heaters 14 and 15 were operated so as to heat the ribbon over its full width during its passage beneath the heating compartment 11. The black body temperature of the radiators over the central part of the ribbon width was 1200° C. and the radiators over the marginal portions of the ribbon were operated at a somewhat higher temperature, so as to raise the temperature of the glass to about 630° C. over the full width of the ribbon.
The spray gun 7 which was of a conventional type was reciprocated across the full width of the ribbon path at a height of 25 cm above the ribbon and was inclined at 30° to the ribbon plane. The gun was fed with air as carrier gas, together with an aqueous solution formed by dissolving hydrated tin chloride (SnCl 2 . 2H 2 O) in water and adding a small amount of NH 4 HF 2 . The rate of supply of the coating solution to the spray gun and its rate of reciprocation were adjusted so that a coating of SnO 2 having a thickness of about 7500 A was formed, such coating having good infrared reflectivity in the wavelength range 2.6 to 40 microns. Examination of the coating showed that it was of good optical quality and of substantially uniform thickness over the full width of the ribbon.
In a comparative process the heating of the glass ribbon over its full width preparatory to entering the coating station was effected by using electrical resistance heating radiators instead of the gas-fired heaters and without using the screens 12,13. It was found that a coating of a high standard of thickness uniformity could still be achieved but the heat output from the radiators had to be higher because of the absence of the screens. Moreover there was a tendency for the steadiness of the droplet stream from the spray gun to be disturbed by convection currents along the lehr. However it was found that this can be obviated by using the heating radiators in conjunction with a single screen, which may be either screen 12 or screen 13, but s preferably screen 13.
EXAMPLE 3
A ribbon of float glass about 2.5 meters in width and travelling from the float tank at 15 meters per minute was coated by a process according to the invention using a vapour phase coating procedure. The ribbon was heated by radiant heaters located above the path of the ribbon to increase the temperature of the glass to a substantially uniform temperature of 600° C. In the absence of such heating the temperature of the glass on entering the coating station would have been approximately 575° C. at the centre of the ribbon and cooler adjacent its edges. On entering the coating station the heated ribbon was contacted with a vapour mixture containing SnCl 4 and SbCl 5 (doping agent) in a volume ratio of 100:1, entrained in a stream of nitrogen. The stream of vapour was caused to flow along the top face of the glass ribbon, in the direction of its travel, by continuously supplying the vapour into a shallow passage defined in part by the glass ribbon and in part by a shroud extending over the ribbon path, and withdrawing residual vapours into exhaust ducting at the downstream end of such passage. The said passage was 50 cm in length and its height decreased from 25 mm at its upstream (entrance) end to 10 mm at its downstream (exit) end. The passage extended over the width of the ribbon except for opposed narrow marginal zones each having a width of 10 cm. A suitable arrangement of such a shroud and exhaust ducting and means for feeding vapours along the glass ribbon, beneath the shroud, is illustrated in United Kingdom patent specification No. 1 524 326. The rate of delivery of the vapour mixture into the said passage and the draught forces through the exhaust ducting were regulated so as to maintain along the passage a substantially turbulence-free flow of vapour mixed with air which was induced to flow into and along the passage by the delivery of the vapour mixture into the passage as above referred to, and so that a coating of SnO 2 incorporating a small quantity of Sb 2 O 5 and having a thickness of 2500 A was formed on the glass ribbon. The coating had a green tint viewed by reflected light and the coated glass had the property of reflecting an appreciable proportion of incident radiation in the far infrared spectral region. The coating was found to be of uniform thickness and to have uniform optical properties over its full transverse extent across the ribbon.
EXAMPLE 4
A ribbon of glass 3 meters in width was drawn in a Libbey-Owens type drawing machine at a speed of the order of 1 meter per minute and was coated in plant as shown in FIG. 2, with the bottom screen 45, but without the barrier wall 46 above the exhaust duct 40. The temperature of the glass measured between the drawing chamber and the heating compartment 31 was 610° C. at the central region of the ribbon and decreased towards its edges.
The screens 32 and 33 forming the upstream and downstream boundary walls of the heating compartment 31 were installed as shown in the figure, corresponding with an inter-screen spacing of approximately 80 cm. The screens were set so that their lower edges were 12 mm above the glass ribbon.
Pre-heated air was discharged, at a volume rate of 900 Nm 3 /hr, at a downward and rearward inclination into the compartment 31 (as indicated by the arrow 44) from a series of ducts 36 extending transversely across the ribbon path, the temperature of the air being higher over the marginal zones of the ribbon path than at its central region. The volume rate of the air supply to such ducts was sufficient to maintain a continuous flow of air out of compartment 31 through each of the slots 34 and 35 and the said supply rate and the pre-heat temperature of the air was such as to increase the temperature of the said marginal zones of the ribbon so that the glass ribbon had a temperature of approximately 610° C. over its full width on entering the coating station.
The exhaust system was operated to extract 6000 Nm 3 /hr via the exhaust ducts 38,39 and 40.
The spray guns 29 and 30 were of a conventional type and were operated at a pressure of the order of 4 kg/cm 2 . The said spray guns were located at a height of 30 cm and 20 cm respectively above the glass ribbon. Gun 29 was set at an angle of 30° and gun 30 was set at an angle of 45° to the ribbon plane.
Spray gun 30 was fed with a 5% by volume concentrated solution of tin dibutyldiacetate in dimethylformamide and was reciprocated across the full width of the ribbon path. The rate of supply of the coating solution of the gun and the speed of its reciprocation were such that an undercoating of tin oxide having a uniform thickness of 60 A was formed on the glass ribbon.
Spray gun 29 was fed with an aqueous solution formed by dissolving hydrated tin chloride (SnCl 2 .2H 2 O) in water in an amount of 375 g per liter and adding per liter 55 g of ammonium bifluoride (NH 4 HF 2 ) and the rate of supply of this solution and the speed of reciprocation of the gun were such as to form on top of the tin oxide undercoating a coating of tin oxide having a thickness of 7500 A. Examination of the coated glass showed that the coatings were of uniformly good quality over their full transverse extent across the ribbon. The coating quality was higher, notably by reason of a greater uniformity, than that obtainable in the absence of the screens 32 and 33 and the pre-heated air supply but under otherwise the same conditions. In the absence of the heating of marginal portions of the glass ribbon the thickness of the coating on those portions would have been less.
In a comparative test the pre-heated air was discharged vertically downwardly from the ducts 36, all other conditions remaining as just previously described. It was found that the volume rate of discharge of the pre-heated air into the compartment had to be increased to 1200 Nm 3 /hr in order to obtain the same coating quality.
In a further comparative test coating was preformed as in the above Example 4 and after a certain time screen 33 was progressively raised from its initial position 12 mm above the glass ribbon. It was found that the screen could be raised to a height of up to 30 mm above the ribbon before pre-heated air ceased to flow upstream from the heating compartment via slot 34.
EXAMPLE 5
A ribbon of drawn glass was coated by the process of Example 4 but with the modification that the second bottom screen 45 was omitted and the pre-heated air was discharged vertically downwardly from the ducts 36 (as indicated by the arrow 37) and the screen 32 was set at a height of 30 mm above the glass ribbon. Under these conditions a coating quality as good as that obtained in Example 4 was obtainable provided the volume rate of supply of pre-heated air to the ducts 36 was sufficiently increased. A suitable volume rate was found to be 1800 Nm 3 /hr.
EXAMPLE 6
A process was performed corresponding with Example 5 but with the modification that the apparatus included a barrier wall 46 above the exhaust duct 40 and a second bottom screen 45 below the ribbon path, and both of the screens 32 and 33 were set at a height of 18 mm above the ribbon. The volume rate of pre-heated air to the ducts 36 over the marginal portions of the glass ribbon was 1200 Nm 3 /hr. Under these conditions coatings of a quality matching those obtained in Example 4 were formed. | In order to control the thickness of a metal or metal compound coating which is formed on a face of a freshly formed ribbon of hot glass during its travel from a flat glass forming installation by contacting such face at a coating station with a fluid medium or fluid media comprising a substance or substances from which the coating is formed, preparatory to being coated, the glass (4) is thermally conditioned (e.g. selectively or differentially heated) at a thermal conditioning station between the flat glass forming installation and the coating station, so as to eliminate or reduce temperature gradients across the ribbon width to be coated.
Apparatus suitable for use in the method comprises means (7-10) for delivering (a) fluid coating medium or media into contact with the glass (4) at the coating station, and means such as heating means (14-16) whereby the temperature of one or more portions of the ribbon width can be conditioned selectively or differentially at a thermal conditioning station located between the flat glass forming installation and the coating station. | 2 |
FIELD OF THE INVENTION
This invention pertains to firearms. More in particular, it pertains to long guns, such as rifles, carbines, and the like, as opposed to pistols. Still more in particular, it pertains to a front grip which may be optionally mounted on certain types of such guns.
ENVIRONMENT OF THE INVENTION
The invention is applicable for use with only a particular type of such gun. This type is that which includes a shroud or forearm on the barrel forward of the operating mechanism. Frequently, these barrel shrouds are provided with a plurality of ventilation openings formed along their length. The invention optional front grip utilizes these barrel shroud openings.
Different weapons have different shapes of openings positioned at different spacings on such barrel shrouds. Thus, when used with any particular weapon, the invention front grip will have to be proportioned so as to accommodate the size and spacing of the particular barrel shroud openings in a particular weapon for which it is designed. This is a more or less trivial matter. The net effect is that each embodiment of the invention will be, in general, custom designed for a particular weapon. However, the feature, a ventilated barrel shroud having a longitudinal row of openings along its bottom surface is very common. For this reason, the invention is applicable to a large number of weapons, even though each particular front grip must necessarily be sized and proportioned for each particular weapon.
FEATURES AND ADVANTAGES OF THE INVENTION
Overall, the invention provides an optional adjustable front grip for such guns. It is advantageous for the invention that it is both optional and adjustable.
Some shooters prefer to grip the barrel shroud itself Thus, they do not want a front grip at all. The present invention would thus find no market with persons of that preference. Other shooters, and perhaps the larger number, do prefer a front grip, for numerous reasons set forth below. However, since people come in many different "sizes", and these differences include the lengths of their arms, it is desirable to have a front grip which is adjustable along the length of the weapon. The invention provides such a grip.
Another advantage of the invention is the design of the handle itself. It is built with a downward and rearward angle to it. This facilitates use of a conventional screwdriver to get access to the adjustable lug to permit mounting and dismounting of the invention handle from the cooperating gun. In addition, this angle is popularly used at present, and thus, matches the other gripping portions of the gun to improve the appearance of the gun when the invention optional handle is provided.
The invention is usable equally well by left-handed and right-handed shooters. This is an important advantage of the invention, for obvious reasons.
A front grip is often desired because it helps to aim the gun, and it helps the user to support the weight of the gun in a more comfortable position. Further, the front grip allows swinging of the muzzle of the gun around using strong muscles of the arm that would not be used if the weapon were held with the palm up, as it would be when gripping the barrel shroud itself. That is, the invention grip allows it to be grasped in a thumb up or fist-like position. In this position, the elbow can be used for maneuvering. In the palm up position, the maneuvering must be done from the shoulder and the elbow is in effect locked Thus, in general, a front grip held in a fist is more desirable than a palm up posture wherein use of the elbow is lost.
Another advantage of a front grip is that it allows better aiming and better weight support, because the user can more efficiently draw the weapon back hard against his shoulder and hold it there firmly during aiming and firing. This has an obvious improvement on accuracy and fatigue.
Another group of advantages of the invention have to do with its interaction with the weapon. The invention grip does not interfere with any of the operating parts of the gun, does not add materially to its weight, does not tend to unbalance the weight distribution of the gun, and does not negatively effect, and to some people it even positively effects, the appearance of a gun fitted with the invention optional front grip.
Another feature and advantage of the invention is the manner of manufacture of the invention front grip. It is preferably fabricated from plastic using mass production molding techniques, having only a single moving part. In this manner, a durable front grip is provided at relatively low cost.
Another advantage of the invention is that it is very simple to install or to remove from a gun. A single screw is all that needs to be manipulated for such mounting or dismounting.
Yet another feature of the invention has to do with the optional front grip serving as a storage means. The grip is hollow and it has a removable plate at its lower end. Upon opening or removing this lower end plate, a space is provided in which cleaning tools, or other miscellaneous small items may be stored. This is a convenience for the user.
Another feature of the invention is that the front grip can be used as a support when the weapon is fired from the prone position. That is, the front grip can be rested directed on the ground when the shooter is in a prone position.
Another advantage of front grips in general is that it permits the shooter to absorb the recoil energy of the gun in both arms more efficiently than he could do if holding the front of the weapon in his palm by the barrel shroud only.
SUMMARY OF THE INVENTION
The invention provides a removable optional front grip for use with guns having a particular type of barrel shroud, namely, one which is formed with a longitudinal row of openings in the bottom surface. The invention grip is designed to cooperate with three adjacent openings in this row of openings, to thereby provide a secure adjusted position of the front grip with respect to the weapon to thereby accommodate users having different arm lengths.
The front grip of the invention is primarily a one piece molded device. It has a hollow body which is closed off by a plate at the lower end. The space within the body is usable for storage, and also provides access to the rearmost of the three attachment lugs. This rear attachment lug is controlled by a screw operated from the inside of the handle by an ordinary screwdriver.
In use of the invention front grip, the rear adjustable lug is first fitted into the rearmost of the three openings which will be used in the barrel shroud. Then the other lugs are rotated upwardly around that rear lug until they fit into adjacent ones of the barrel shroud openings. Finally, after all three lugs are in position in their three holes, the grip is slid forward. Then, a screwdriver is used through the inside of the hollow handle to tighten the rear lug. The grip is then securely fastened to these three holes in the barrel shroud
Disassembly is simply the above steps performed in reverse; first the single screw is loosened, then the grip slid rearwardly, and then it is rotated out of position and removed from the gun.
In this manner, the invention provides a removable front grip which is easily adjusted for different size persons using the gun; and which can be manufactured to fit a wide variety of guns, in fact all guns having a ventilated barrel shroud wherein, the ventilation is provided by a row of openings along the bottom of the shroud. Still further, the invention provides such a grip which is simple in design and readily adaptable to mass production at relatively low cost. The invention grip is very simple to mount and dismount and is highly reliable and efficient in operation. Finally, the invention provides a thumbs up or fist grasp for the invention front grip, which arrangement has numerous advantages as set forth above.
The invention will be best understood from a careful reading of the following detailed description taken in conjunction with the enclosed drawings, which drawings form a part of this disclosure, and in which:
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
FIG. 1 is a side elevational view of a typical weapon with which the invention front grip can be used;
FIG. 2 is a top front perspective view of a preferred embodiment of the invention grip;
FIG. 3 is a vertical longitudinal cross-sectional view taken generally on line 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view looking on line 4--4 of FIG. 1 with certain parts omitted for the sake of clarity;
FIG. 5 is a top view of the front grip looking from the upper side of FIG. 2;
FIGS. 6-9 are a series of "action" drawings showing the manner of mounting and dismounting of the invention grip on a firearm; and
FIG. 10 is a cross-sectional view of a detail taken on line 10--10 of FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawings, in FIG. 1 there is shown a front grip 10 mounted on a weapon 12 which is representative of a large class of weapons with which the invention can be used. Gun 12 shown is of a design which is owned in common the present invention.
Gun 12, representative of its class, includes a barrel 14 and a barrel shroud 16. The shroud 16 is provided to protect the user's front hand holding the weapon from the heat generated in the barrel in use.
The feature about barrel shroud 16 which is important for the invention is a row of openings 18 formed at regularly spaced intervals over its entire length. The showing of FIG. 1 has been distorted by putting the openings 18 to one side, where they are visible in the drawing. In fact, the openings 18 are provided along the bottom surface axially aligned with the vertical plane of the gun. Reference should be had to FIG. 4 to see the accurate positioning of the openings 18.
Referring now to FIGS. 2 and 3, the invention grip is shown in some detail. It is basically of a conventional handle-like shape, adapted to be gripped in a fist in a thumbs up posture. It is formed with a top wall 20 formed with a pair of fixed locking lugs 22. A third adjustable locking lug 24 is provided. The spacing between the three lugs 22, 22 and 24 is such as to match the spacing of the openings 18 in the barrel shroud 16. Each lug 22, 22 and 24 includes a front hook portion, see FIG. 3, for a purpose described below.
Extending downwardly from all sides of the top wall 20 is a main body wall 26 which defines an internal cavity 28. Finally, the handle of the invention 10 includes a bottom removable door or lid 30. The lid is shown in a closed position in FIGS. 2, 9 and 10, and in a removed position in FIG. 3. The lid is removed so that access by a screwdriver 32 to the adjustable lug assembly 24 can be had through the space 28 in handle 10. Also, this space is usable for storing cleaning materials, spare parts, ear plugs, or other miscellaneous items.
As shown in FIGS. 1 and 2, the main wall 26 can be provided with numerous design features, grip enhancing ridges, trademarks, names, data, and the like. Further, the handle 10 is preferably made in such a manner that it matches the fixed rear grip 34 forming part of weapon 12, see FIG. 1.
The adjustable lug assembly comprises an enlarged boss portion 36 formed on the inside rear corner at the junction of the top wall 20 and the main wall 26. A through opening is formed in which is fitted a single screw 38. The screw cooperates with a threaded opening in a movable locking lug portion 40 forming the rear part of the rear lug assembly 24. The remaining portion of the rear lug assembly 24 comprises an extending lip portion which matches exactly the forward portions of the other two fixed lugs 22. This is shown clearly in FIGS. 2 and 3, especially FIG. 3
As can be seen, the invention handle is simple and easy to manufacture. The walls 20 and 26 together with the lugs 22 and the front part of lug assembly 24 can be molded all in one piece of a durable high impact plastic suitable for use in firearms. The remaining parts of the grip are the bottom lid 30, the screw 38, and the movable lug portion 40. Thus, the invention can be manufactured at relatively low cost, and be made to be quite durable and highly reliable in use.
Further in regard to the lid 30, one manner in which it can be secured to the bottom end of the handle is illustrated in FIG. 10. This is the successfully constructed embodiment, but other arrangements, well known to those skilled in the art, can also be provided.
For example as to other arrangements, the invention could be used with a barrel shroud having a large number of relatively small ventilation holes, or with an arrangement of alternating large and small holes. In such cases, simple changes to accommodate would be made in the invention grip, i.e., use every other hole, or use lugs of different sizes, or use 2 or 4 lugs, or use more lugs, or provide more locking lugs, etc.
The manner of operation of the invention will be best understood from a review of the remaining FIGS. 4-9, together with the following description.
Referring first to FIG. 6, the movable lug part 40 has been moved to the outer end of the screw 38 and has been inserted in the rearmost of a set of three of the holes 18 in the shroud 16. Then, as indicated in the motion between FIGS. 6 and 7, the fixed two lugs 22 are rotated up into the two forwardly adjacent openings 18 in the shroud 16. Then, the handle assembly 10 is slid forwardly so that the hock parts of the three lugs 22 and 24 grasp the forward portions of their three respective openings 18. This is indicated by the arrow in FIG. 7. Then, using the screwdriver 32, and screw 38 is operated to bring lug part 40 down into tight locking engagement with the rear portion of its opening 18. At this point, the handle is securely locked in position on the shroud. It cannot move forward or backward due to the three lugs 22 and 24. The locking action is indicated by the arrow in FIG. 8. FIG. 9 shows the lid 30 put back in place on the bottom of the handle 10, thus completing the mounting procedure.
To dismount the handle, the action indicated by FIGS. 6, 7, 8 and 9 are performed in reverse.
FIG. 4 shows the holes 18 in phantom view as they are engaged with the three lugs 22 and 24. FIG. 5 shows a top plan view of the handle 10 with the three lugs clearly visible.
While the invention has been described in detail above, it is to be understood that this detailed description is by way of example only, and the protection granted is to be limited only within the spirit of the invention and the scope of the following claims. | An optional removable front grip usable with any firearm having a barrel shroud formed with a row of regularly spaced openings on its underside. Such openings are routinely provided to ventilate the barrel. The invention front grip is hollow and is provided with a set of lugs which engage any three adjacent barrel shroud ventilation openings to thereby accommodate shooters having different arm lengths. One of the lugs is a locking lug which is operated easily by a screwdriver inserted through the hollow grip. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates to a halogen-free epoxy resin composition. The flame retardant properties of the composition can reach the UL 94V-0 standard without adding a compound or resin component containing halogen, and the composition has high heat resistance.
BACKGROUND OF THE INVENTION
[0002] Because of easy processing, high safety, excellent mechanical and chemical properties, composite materials, especially the epoxy resin composite materials have been widely used in coatings, electrical insulation, building materials, adhesives and laminated entities. For instance, since epoxy resins have strong adhesion to reinforcement materials such as glass-fiber fabric, no volatility and small shrinkage of the forming product while hardening. A laminated plate produced by such resins has the advantage of a broad range of usability, good mechanical strength, good electrical insulation property, excellent resistance to chemicals and the like. The reliability of such a laminated plate has been increased, and such an epoxy resin laminated plate has been massively applied to electrical and electronic products.
[0003] However, since the demand for finer circuits and higher density of the printed circuit board increases day by day, it has been necessary to develop a laminated plate with better electrical and mechanical properties, as well as heat resistance during processing. For the FR4 laminated plate widely used at present, the glass transition temperature (Tg) after hardening is about 130° C. Thus, with the temperature over 200° C. during cutting and drilling, and even over 270° C. during the welding procedure during the printed circuit board process, the laminated plate breaks or cracks easily. The expansion of FR4 laminated plate in the direction of the plane is about 12 to 17 ppm/° C. For less than 100 μm of line width/line space of a developing printed circuit board, such a laminated plate is not suitably applied in HDI field. Therefore, various laminated plate materials that possess high heat stability and high glass transition temperature are being developed.
[0004] Another important property for laminated plates is flame retardance. The flame retardant properties of a printed circuit board are absolutely necessary to protect human life when the printed circuit board is used in traffic vehicles such as airplanes, automobiles, and public transportation vehicles. In order to enhance the flame retardant properties of the laminated plate, substances that can isolate the flame and reduce burning should be used. For laminated plates of the epoxy resin/glass-fiber series (or organic fiber series), halogen-containing compounds, especially bromine-containing epoxy resins and hardeners, are used in combination with flame retardants such as antimony trioxide and the like, so the flame retardant properties of the laminated plates can meet the required standard (such as the UL 94V-0 grade). Generally, for reaching the UL94V-0 standard, epoxy resins containing bromine as high as 17 to 21% in combination with antimony trioxide or other flame retardant are used. However, the use of flame retardants containing halogen and antimony trioxide can seriously affect the health of humans.
[0005] First, it has been reported that antimony trioxide is a carcinogenic substance. Additionally, erosive free radicals and hydrogen bromide generated by bromine burning, and also toxic furan bromides and a dioxin bromide compound produced from aromatic compounds with high bromine contents during burning seriously endanger human health and the environment. Therefore, it is most urgent to find a novel flame retardant material which solves the pollution and environmental problems caused by the current use of laminated products containing bromo-epoxy resins. And, since FR-4 epoxy glass fiber laminated plates are commonly used for electronic products, the requirement of flame retardant material is especially important.
[0006] Currently, phosphorus system compounds have been extensively studied and applied in the new generation of environment-friendly flame retardant materials, for example, red phosphorus or phosphorus-containing organic compounds (such as triphenyl phosphonate and tribenzyl phosphonate, etc.) are directly added to substitute halide compounds as a flame retarder to improve the flame resistance of polymer materials or hardening resin materials. However, direct addition of such flame retardant compounds in large amounts into resins is always required to achieve the effect of flame retardancy. Due to the smaller molecular weight of the compound, higher migration will affect the properties of resin substrates, for example, electronic properties, adhesive strength, and the like, resulting in difficulty in application.
[0007] Therefore, in the halogen-free resin composition of the present invention, a phosphorus-containing epoxy resin (particularly, a side chain type phosphorus-containing epoxy resin) and a hardener having the benzoxazine cyclic structure are used. The flame retardant properties of such a resin composition can meet the UL 94V-0 standard without adding a halogen-containing compound or resin, and such a resin composition has higher heat resistance relative to other resin compositions comprising a conventional hardener.
[0008] Generally, compounds having the benzoxazine cyclic structure are prepared by the reaction of a phenolic compound, an amine compound, and an aldehyde compound. But many patents disclose the method for preparing the compounds having the benzoxazine cyclic structure, which are prepared by the reaction of aniline and phenolic compound. For example, U.S. Pat. No. 6,005,064 disclosed a thermosetting resin having the benzoxazine cyclic structure prepared by the reaction of a phenolic resin, formaldehyde and aniline; and JP-A-Hei-11-50123 also disclosed the method for preparing dihydrobenzoxazine thermosetting resin from bisphenol, aniline, and formalin using methyl ethyl ketone as a solvent. However, the aniline used in these preparation methods is toxic, and is a forbidden chemical by law. Also, the preparation methods cannot meet the requirements of the mass production in industry.
[0009] Therefore, the present inventors have conducted extensive studies and have found that the system was endowed with relatively high stability when using hydrocarbon solvent to conduct the reaction of phenolic compounds, aromatic diamines, and aldehyde compounds. In addition to not using toxic aniline as a reactant, compounds having the benzoxazine cyclic structure conducts the ring-reopening polymerization at high temperature due to improper temperature control can be prevented. Meanwhile, the present invention can prevent the gelation or agglomeration caused by using high polar solvent or protic solvent to undergo the reaction. Therefore, the present invention is useful in mass production in industry.
SUMMARY OF THE INVENTION
[0010] The present invention provides a halogen-free resin composition comprising (A) one or more phosphorus-containing epoxy resins; (B) a hardener; (C) a hardening accelerator, wherein the hardener of component (B) has the structure represented by the following formula (I):
[0011] wherein each symbol is as defined in detailed description that follows. The halogen-free resin composition of the present invention has superior heat resistance and flame retardance property without adding a halogen-containing component in the composition, solving the pollution and environmental problems caused by using the conventional halogen-containing flame retardant resin composition.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The present invention provides a halogen-free resin composition comprising (A) one or more phosphorus-containing epoxy resins; (B) a hardener; (C) a hardening accelerator, wherein the hardener of component (B) has the structure represented by the following formula (I):
[0013] wherein R 1 represents a compound selected from the group consisting of an alkyl group, an alkenyl group, an alkoxy group, a hydroxy group and an amino group; R 2 represents a compound selected from the group consisting of a chemical bond, an alkylene group, O, S and SO 2 ; R 3 represents H or an alkyl group; m and n are integer from 0 to 4.
[0014] In the structure represented by the above formula (I), the alkyl group represented by R 1 and R 3 means linear, branched or cyclic alkyl of 1 to 6 carbon atoms. Examples thereof include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, amyl, 2-amyl, 3-amyl, 2-methyl-1-butyl, isoamyl, s-amyl, 3-methyl-2-butyl, neo-amyl, hexyl, 4-methyl-2-amyl, cyclopentyl, cyclohexyl, and the like. Alkoxy group means linear, branched or cyclic alkoxyl of 1 to 6 carbon atoms. Examples thereof include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, s-butoxy, t-butoxy, amoxy, isoamoxy, neo-amoxy, hexoxy, cyclohexoxy, and the like. Alkylene group means linear, branched or cyclic alkylene group of 1 to 6 carbon atoms. Examples thereof include, but are not limited to methylene, ethylene, propylene, butylene, amylene, hexylene, 2-methylpropylene, 2,2′-dimethylpropylene, hexylene, 2,3-dimethylbutylene, and the like.
[0015] The azaoxa heterocyclic compound having the structure represented by the formula (I) is prepared by the reaction of a phenolic compound, an aromatic diamine compound, and an aldehyde compound in the presence of a solvent. The phenolic compound may be a substituted or unsubstituted phenolic compound, and examples of the substituents include, but are not limited to, an alkyl group, an alkenyl group, an alkoxyl group, a hydroxy group, and an amino group.
[0016] Examples of the above substituted or unsubstituted phenolic compounds include, but are not limited to, o-cresol, p-cresol, m-cresol, ethylphenol, propylphenol, isopropylphenol, butylphenol, s-butylphenol, t-butylphenol, amylphenol, isoamylphenol, hexylphenol, cyclohexylphenol, allylphenol, 4-methoxyphenol, 3-methoxyphenol, 2-methoxyphenol, 4-vinylphenol, 3-vinylphenol, 2-vinylphenol, 4-hydroxyphenol, 3- hydroxyphenol, 2-hydroxyphenol, 4-aminophenol, 3-aminophenol, 2-aminophenol, 4-hydroxycresol, 3-hydroxycresol, 2-hydroxycresol, 4-hydroxymethyl-2-methoxyphenol, 4-hydroxymethyl-3-methoxyphenol, 4-isopropyl-2-methoxyphenol, 4-isopropyl-3-methoxyphenol, 2-hydroxy-4-isopropylphenol, 3-hydroxy-4-isopropylphenol, 4-vinyl-2-methoxyphenol, 4-vinyl-3-methoxyphenol, 4-vinyl-2-hydroxyphenol, 4-vinyl-3- hydroxyphenol and the like.
[0017] The phenolic compounds used for preparing the azaoxa heterocyclic compound represented by the formula (I) are not particularly limited. The phenolic compounds can be mono-functional phenolic compounds, bi-functional phenolic compounds and multi-functional phenolic compounds, provided that at least one of hydrogen atoms on ortho-positions to the hydroxy group in the aromatic ring is unsubstituted.
[0018] The aromatic diamine compounds used for preparing the azaoxa heterocyclic compound represented by the following formula (I) are represented by the following formula (II):
[0019] wherein R 2 , R 3 and m are as defined above.
[0020] Examples of the aromatic diamine compounds represented by the formula (II) include, but are not limited to, diaminobiphenyl compounds, for example, 4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-dimethylbiphenyl, 4,4′-diamino-2-butyl-3-methylbiphenyl, 4,4′-diamino-2-ethyl-3-isopropylbiphenyl, 4,4′-diamino-2-methyl-3-propylbiphenyl, 4,4′-diamino-2-methylbiphenyl, 4,4′-diamino-3-isopropylbiphenyl and the like; the diaminodiphenylalkane compounds, for example, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenylpropane, 4,4′-methylene bis(2-methylaniline), 4,4′-ethylene bis(3-isopropylaniline), 4,4′-methylene bis(2,6-dipropylaniline), 4,4′-ethylene bis(2,5-dibutylaniline), 4,4′-methylene bis(2-ethyl-6-propylaniline), 4,4′-methylene bis(2-isopropyl-6-methylaniline) and the like; the diaminodiphenyl ether compounds, for example, 4,4′-diaminodiphenylether, di(4-amino-3-ethylphenyl)ether, di(4-amino-3-hexylphenyl)ether, di(4-amino-3,5-dimethylphenyl)ether and the like; the diaminodiphenyl thioether compound, for example, 4,4′-diaminodiphenyl thioether, di(4-amino-3-propylphenyl)thioether, di(4-amino-3-t-butylphenyl)thioether, di(4-amino-3,5-diethylphenyl)thioether and the like; the diaminodiphenyl sulfone compounds, for example, 4,4′-diaminodiphenyl sulfone, di(4-amino-3-isopropylphenyl)sulfone, di(4-amino-3,5-diamylphenyl)sulfone and the like.
[0021] The aldehyde compounds used for preparing the azaoxa heterocyclic compounds represented by the formula (I) are not particularly limited, provided that aldehyde compounds are used for preparing the azaoxa heterocyclic compound having the benzoxazine cyclic structure. Examples of the aldehyde compound include, but not limited to, aldehyde (or vapor thereof), paraformaldehyde, polyoxymethylene and the like.
[0022] The azaoxa heterocyclic compounds represented by the formula (I) are prepared by the polymerization of a phenolic compound, an aromatic diamine compound, and a aldehyde compound, wherein the phenolic compound, the aromatic diamine compound and the aldehyde compound used in the polymerization are present in an equivalent ratio of 2:1:4.
[0023] The solvent used for preparing the azaoxa heterocyclic compounds represented by the formula (I) are not particularly limited, provided that all the reactants can be suitably dissolved in the solvent. Examples of the solvent include, but are not limited to, alcohol solvents such as methanol, ethanol, propanol, isopropanol, ethandiol and the like; ether solvents such as 1,2-dimethoxyethane, tetrahydrofuran, dioxane and the like; ketone solvents such as acetone, methyl ethyl ketone, methyl isopropyl ketone and the like; ester solvents such as methyl acetate, ethyl acetate, and the like; and hydrocarbon solvents such as toluene, xylene, and the like. In comparison to the above polar solvents, the hydrocarbon solvents used in the present invention have relatively low polarity. The hydrocarbon solvent used can not only dissolve the phenolic compound and the aromatic diamine compound, but also it can scatter the aldehyde compound so that the agglomeration does not easily occur. Therefore, the stability of the reaction system is enhanced, and thus the formed azaoxa heterocyclic compounds having the benzoxazine cyclic structure will not further undergo ring-opening polymerization at very high temperature caused by the improper temperature-control. Therefore, the preferred solvent used in the present invention is a hydrocarbon solvent.
[0024] In the halogen-free resin composition of the present invention, the phosphorus-containing epoxy resins (component A) are not limited, and they can be any phosphorus-containing epoxy resin. Among them, a side chain type phosphorus-containing epoxy resin is preferred. The preferred examples of the side chain type phosphorus-containing epoxy resin include, but are not limited to:
[0025] (1) The side chain type phosphorus-containing epoxy resin prepared by directly introducing the organic cyclic phosphorus-containing compound (for example, 9,10-dihydro-9-oxa-10-phosphorylphenanthrene-10-oxide, (hereinafter referred to as HCA)) into the structure of the epoxy resin, and is represented by the following formula (III):
[0026] wherein Epoxy represents an epoxy resin in which at least one of epoxy groups is ring-opened; and
[0027] (2) initially reacting the organic cyclic phosphorus-containing compound HCA and the aromatic aldehyde compound with the aromatic compound having reactive hydrogens to form a multi-functional phosphorus-containing compound (the phosphorus-containing compound has bisphenol-like structure, the difference in structure between them being one hydrogen or organic group in the center of the phosphorus-containing compound structure being substituted with HCA), then undergoing the additive reaction of the multi-functional phosphorus-containing compound and epoxy resin to introduce the phosphorus-containing compound into the structure of the epoxy resin to form a side chain type phosphorus-containing epoxy resin represented by the following formula (IV):
[0028] wherein Epoxy is as defined above; and Ar 1 and Ar 2 are independently selected from:
[0029] wherein R 4 is selected from the group consisting of —OH, —COOH, —NH 2 , —CHO, —SH, —SO 3 H, —CONH 2 , —NHCOOR 7 and an anhydride; R 5 is selected from the group consisting of hydrogen, an alkyl group, an alkoxyl group, a nitro group and an aromatic group; R 6 is selected from the group consisting of a bond or an alkylene group; R 7 is H or alkyl group; R 8 is selected from the group consisting of a bond, —CR 5 R 7 —, —O—, —CO—, —S—, —SO— and —SO 2 —; a and b are independent integers from 0 to 6, and a+b≦6; c and d are independent integers from 0 to 4, and c+d≦4; and z is an integer from 1 to 20.
[0030] Examples of an alkyl group, an alkylene group and an alkoxy group represented by the above R 5 , R 6 and R 7 are as defined above. Examples of an aromatic group represented by R 5 include phenyl, tolyl, xylyl, benzyl, naphthylm, and the like.
[0031] In the halogen-free resin compound, a side chain type phosphorus-containing epoxy resin represented by the formula (III) or the formula (IV) prepared by undergoing the additive reaction of any epoxy resin and the organic cyclic phosphorus-containing compound HCA or the phosphorus-containing compound made from HCA is used as one or more phosphorus-containing epoxy resins (component A). An example of the epoxy resin include, but are not limited to, bi-functional epoxy resin. The so-called “bi-functional epoxy resin” means the resin has two or more epoxy groups per molecule, for example, the epoxy groups formed by the oxidation of olefin, the glycidyl etherification of hydroxy groups, glycidyl amination of primary and secondary amines, or glycidyl esterification of carboxylic acids.
[0032] The compounds used for undergoing such a epoxidation include catechol, resorcinol, hydroquinone, and the like; bisphenols such as 2,6-hydroxynaphthalene, 2,2-bis(4-hydroxyphenyl)propane (i.e. bisphenol A), 2-(3-hydroxyphenyl)-2-(4′-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane (i.e. bisphenol F), bis(4-hydroxyphenyl)sulfone (i.e. bisphenol S), bis(4-hydroxyphenyl)thioether, bis(4-hydroxyphenyl)toluene, bis(4-hydroxyphenyl)methylcyclohexane, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxy-3,3′,5,5′-tetramethyl-biphenyl, 4,4′-dihydroxybiphenyl ether, 6,6′-dihydroxy-3,3,3′,3′-tetramethyl-1,1-spirodiindan and 1,3,3-trimethyl-1-(4-hydroxyphenyl)-1-indan-6-ol and the like; oligophenols such as tetraphenolicethane, naphthaleneol-cresol resol resin phenolic resin, and the like; phenolic resin such as phenol-aldehyde resin, phenol aromatic alkyl group, naphthaleneol aromatic alkyl group, phenol-bicyclopentdiene copolymer resin, and the like; aliphatic and aromatic amine such as ethylene diamine, propylene diamine, hexamethylene diamine, aniline, 4,4′-diaminodiphenylmethane (MDA), 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfone, 2,2′-bis(4,4′-diaminophenyl)propane, m-xylyl diamine, p-xylyl diamine, 1,2-diaminocyclohexane, aniline aromatic alkyl resin, and the like; aminophenols such as m-aminophenol, p-aminophenol, 2-(4-aminophenyl)-2-(4′-hydroxyphenyl)propane, 4-aminophenyl-4-hydroxyphenylmethane and the like; carboxylic acids such as phthalic acid, isophthalic acid, p-phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, dimeric acid, 1,3-dicarboxycyclohexane and the like; and hydroxycarboxylic acids such as salicyclic acid and 4-hydroxybenzoic acid.
[0033] In the halogen-free resin composition of the present invention, the preferred epoxy resin composition used in forming a side chain type phosphorus-containing epoxy resin is glycidyl ethers. Examples of monomers for the epoxy resin include: bisphenol glycidyl ether, biphenyl glycidyl ether, benzenediol glycidyl ether, nitrogen-containing hetero-ring glycidyl ether, dihydroxynaphthalene glycidyl ether, phenolic glycidyl ether, polyhydric phenol glycidyl ether, and the like.
[0034] Examples of bisphenol glycidyl ether include: bisphenol A glycidyl ether, bisphenol F glycidyl ether, biphenyol AD glycidyl ether, bisphenol S glycidyl ether, tetramethylbisphenol A glycidyl ether, tetramethylbisphenol F glycidyl ether, tetramethylbisphenol AD glycidyl ether, tetramethylbisphenol S glycidyl ether, and the like.
[0035] Examples of biphenol glycidyl ether include: 4,4′-biphenol glycidyl ether, 3,3′-dimethyl-4,4′-biphenol glycidyl ether, 3,3′,5,5′-tetramethyl-4,4′-biphenol glycidyl ether, and the like.
[0036] Examples of benzenediol glycidyl ether include: resorcinol glycidyl ether, hydroquinone glycidyl ether, isobutylhydroquinone glycidyl ether, and the like.
[0037] Examples of nitrogen-containing hetero-ring glycidyl ether include: triglycidyl ether of isocyanurate, triglycidyl ether of cyanurate, and the like.
[0038] Examples of dihydroxynaphthalene glycidyl ether include: 1,6-dihydroxynaphthalenediglycidyl ether, 2,6-dihydroxynaphthalenediglycidyl ether, and the like.
[0039] Examples of phenolic polyglycidyl ethers include: phenolic polyglycidyl ether, cresol phenolic polyglycidyl ether, bisphenol A phenolic polyglycidyl ether, and the like.
[0040] Examples of phenylpolyhydric phenol glycidyl ether include: tris(4-hydroxyphenyl)methane polyglycidyl ether, tris(4-hydroxyphenyl)ethane polyglycidyl ether, tris(4-hydroxyphenyl)propane polyglycidyl ether, tris(4-hydroxyphenyl)butane polyglycidyl ether, tris(3-methyl-4-hydroxyphenyl)methane polyglycidyl ether, tris(3,5-dimethyl-4-hydroxyphenyl)methane polyglycidyl ether, tetrakis(4-hydroxyphenyl)ethane polyglycidyl ether, tetrakis(3,5-dimethyl-4-hydroxyphenyl)ethane polyglycidyl ether, dicyclopentene-phenolic polyglycidyl ether, and the like.
[0041] The additive reaction for preparing a side chain type phosphorus-containing epoxy resin represented by the formula (III) or formula (IV) can be conducted in molten state without solvent, or in reflux with solvent. Examples of the solvent used in reflux include, but not limited to: organic aromatics solvents such as toluene, xylene and the like; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and the like; ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether and the like; esters such as ethyl acetate, ethyl isopropionate, propylene glycol monomethyl ether acetate and the like; hydrocarbons such as toluene and xylene and the like; and aprotic solvent such as N,N-dimethylformamide, N,N-diethylformamide, dimethylsulfoxide, and the like.
[0042] The reaction for preparing a side chain type phosphorus-containing epoxy resin represented by the formula (III) or formula (IV) typically is carried out at a temperature of 50 to 350° C., preferably 50 to 300° C., more preferably 100 to 250° C., and still more preferably 100 to 200° C. Side reaction tends to occur and the reaction rate is not easily controlled if the temperature is higher than 350° C., which will speed up the deterioration of the resin. On the other hand, the efficiency of the reaction gets worse and the formed resin cannot be applied in the high temperature environment if the reaction temperature is lower than 50° C.
[0043] In the halogen-free resin composition of the invention, these phosphorus-containing epoxy resins can be used singly or in combination as a mixture of two or more different kind of resins. One or more phosphorus-containing epoxy resins (component A) are typically used in an amount of 40 to 80 percent by weight, preferably 50 to 80 percent by weight, and more preferably 60 to 80 percent by weight based on the total amount of the phosphorus-containing epoxy resins (component A) and the hardener (component B). If the amount of one or more phosphorus-containing epoxy resins (component A) is smaller than 40 percent by weight, the heat resistance and the flame retardant property of the product after hardening tend to be insufficient, which is not beneficial in application.
[0044] In the halogen-free resin composition of the invention, examples of the hardening accelerator (component C) include: tertiary amine, tertiary phosphine, quaternary ammonium salt, quaternary phosphonium salt, boron trifluoride complex salt, lithium-containing compound, imidazole compound or mixtures thereof.
[0045] Examples of the tertiary amines include: triethylamine, tributylamine, dimethylaniline, diethyl aniline, α-methylbenzyldimethylamine, dimethylaminoethanol, N,N-dimethyl-aminocresol, tris(N,N-dimethyl-aminomethyl)phenol, and the like.
[0046] An examples of tertiary phosphines includes triphenylphosphine.
[0047] Examples of quaternary ammonium salt include: tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetraethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium iodide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, triethylbenzylammonium chloride, triethylbenzylammonium bromide, triethylbenzylammonium iodide, triethylphenylethylammonium chloride, triethylphenylethylammonium bromide, triethylphenylethylammonium iodide, and the like.
[0048] Examples of quaternary phosphonium salt include: tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium iodide, tetrabutylphosphonium acetate, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetraphenylphosphonium iodide, ethyltriphenylphosphonium chloride, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium acetate, ethyltriphenylphosphonium phosphate, propyltriphenylphosphonium chloride, propyltriphenylphosphonium bromide, propyltriphenylphosphonium iodide, butyltriphenylphosphonium chloride, butyltriphenylphosphonium bromide, butyltriphenylpbosphonium iodide, and the like.
[0049] Examples of imidazole compound include: 2-methylimidazole, 2-ethylimidazole, 2-laurylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 4-methylimidazole, 4-ethylimidazole, 4-laurylimidazole, 4-heptadecylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-hydroxymethylimidazole, 2-ethyl-4-methylimidazole, 2-ethyl-4-hydroxymethylimidazole, 1-cyanoethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and the like.
[0050] These hardening accelerators can be used singly or in combination as a mixture of two or more different kind of hardening accelerators. Among them, the hardening accelerator is preferably the imidazole compound and the quaternary phosphonium salt, preferably 2-methylimidazole, 2-phenylimidazole, ethyltriphenylphosphonium acetate, butyltriphenylphosphonium bromide or mixtures thereof.
[0051] In the halogen-free resin composition of the invention, the hardening accelerator is used in an amount of 0.01 to 1 percent by weight, preferably 0.01 to 0.5 percent by weight, and more preferably 0.02 to 0.1 percent by weight relative to the total weight of the resin composition.
[0052] The flame retardant resin composition of the invention can be formulated into varnish. The viscosity of the resin composition can be adjusted by the addition of a suitable solvent when the resin composition of the invention is formulated into varnish. The viscosity of the resin composition is preferably in the range of 20 to 500 cps/25° C.
[0053] The solvents used for adjusting the viscosity of the resin composition include organic aromatic solvents, protic solvents, ketones, ethers, esters, and the like.
[0054] Examples of the organic aromatic solvents include toluene and xylene; examples of protic solvents include N,N-dimethylformamide, N,N-diethylformamide, dimethylsulfoxide and the like; examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone and the like; examples of ethers include ethylene glycol monomethyl ether, propylene glycol monomethyl ether and the like; and examples of esters include ethyl acetate, ethyl isopropionate, propylene glycol monomethyl ether acetate, and the like.
[0055] Optional additives or modifiers used in the halogen-free resin composition of the invention include heat stabilizers, light stabilizers, UV assorbents, plasticizers, and the like.
[0056] The halogen-free resin composition of the invention can be:
[0057] A laminate manufactured by a copper foil, a fiber substrate, and the resin composition of the invention using a method known in the art.
[0058] The prepreg can be manufactured by impregnating a suitable substrate with varnish formulated by the halogen-free resin composition of the invention and drying the impregnated substrate with heat. Examples of these substrates include, but are not limited to, fiber substrate, such as, glass fiber, metallic fiber, carbon fiber, aramide fiber, PBO fiber, LCP fiber, Kelvar fiber, aromatic ester, boron, cellulose and the like; mat substrate, for example, glass fiber cloth; and paper substrate, such as, aramide paper, LPC paper, and the like. The prepreg can be further made into composite material laminated plates, or it can be used alone in a binding layer of prepregs. Additionally, copper foil is placed on one or both surfaces of a prepreg or a combination of prepregs, which is then pressurized and heated to obtain a laminate plate. The laminated plate thus obtained is by far superior to the standards of the present products on the market in respect to size stability, resistance to chemicals, resistance to corrosion, moisture absorption, and electrical properties, and it is suitable in producing electrical products for electronics, space applications and transport vehicles, for example, in producing printed circuit boards, multi-layer circuit boards, and the like.
[0059] The hardening reaction for the halogen-free resin composition of the invention is typically carried out at a temperature of 20 to 350° C., preferably 50 to 300° C., more preferably 100 to 250° C., and still more preferably 120 to 220° C. Side reaction tends to occur and the hardening reaction rate is not easily controlled if the hardening reaction temperature is too high, which will speed up the deterioration of the resin. On the other hand, the efficiency of the hardening reaction decreases and the formed resin cannot be applied in a high temperature environment if the hardening reaction temperature is too low.
[0060] The flame retardant properties of the halogen-free resin composition of the invention can reach the UL 94V-0 standard without adding other processing aids and flame retardant additives, especially halogen, and the resin composition has high heat resistance and an excellent dielectric property.
[0061] The features and the effects of present invention will be described in more detail by way of examples, which should not be construed as limiting the scope of the invention.
EXAMPLES
[0062] Each component used in the examples and the synthesis examples is illustrated as following:
[0063] Epoxy resin 1 represents a diglycidyl ether of bisphenol A, sold under trade name BE188EL and manufactured by Chang Chun Plastics Co., Ltd., Taiwan. The epoxy equivalent weight thereof is in the range of 185 to 195 g/eq. The hydrolytic chlorine content is below 200 ppm, and the viscosity is in the range of 11000 to 15000 cps/25° C.
[0064] Epoxy resin 2 represents a polyglycidyl ether of cresol-aldehyde concentrate, sold under trade name CNE200ELF and manufactured by Chang Chun Plastics Co., Ltd., Taiwan. The epoxy equivalent weight thereof is in the range of 200 to 220 g/eq, and the hydrolytic chlorine content is below 700 ppm (measured by ASTM method).
[0065] Hardener A represents a solution of 10% dicyandiamide (DICY) in DMF.
[0066] Hardener B represents a solution of 10% 4,4′-diaminosulfoxide (DDS) in DMF.
[0067] Hardening accelerator A represents a solution of 10% 2-methylimidazole (2MI) in methyl ethyl ketone.
[0068] The epoxy equivalent weight (EEW), the varnish viscosity, and solid content herein are measured by the following method:
[0069] (1) Epoxy equivalent weight: the epoxy resin is dissolved in a mixed solvent (chlorobenzene:chloroform=1:1), then the mixture is titrated with HBr/glacial acetic acid. EEW is determined according to the method in ASTM D1652. The indicator used is crystal violet.
[0070] (2) Viscosity: the varnish of the epoxy resin composition is placed into a thermostat at 25° C. for 4 hours, and the viscosity is measured by a Brookfield viscosimeter at 25° C.
[0071] (3) Solid content: After baking 1 g of the varnish sample containing the epoxy resin composition at 150° C. for 60 minutes, the non-volatile components in percent byweight are determined, which is the solid content.
Synthesis Example 1
[0072] 216 g of a dried 9,10-dihydro-9-oxa-10-phosphorylphenanthrene-10-oxide (hereinafter is referred to the organic cyclic phosphorus-containing compound, HCA) was charged into a 3000 mL of five-neck glass autoclave equipped with an electrically-heating mantle, a temperature-controlling apparatus, an electrically-driving stirrer, a stirring bar, a thermocouple, a water-cooling condenser and an addition funnel, and then HCA was dissolved by heating under stirring in the glass autoclave. After heated up to 110° C., 112 g of 4-hydroxybenzaldehyde and 940 g of phenol were added. The reaction is conducted for at least 3 hours. Subsequently, the unreacted phenol was recovered. The product was washed with methanol after the reaction had completed. After cooling to room temperature, the product was filtered and dried, and 9,10-dihydro-9-oxa-10-phosphorylphenanthrene-10-oxide-10-yl)-(4-hydroxyphenyl)methanol (hereinafter referred to as the phosphorus-containing compound, HPP was obtained.
[0073] 1000 g of epoxy resin 1 and 550 g of phosphorus-containing compound HPP were charged into a 3000 mL five-neck glass autoclave equipped with an electrically-heating mantle, a temperature-controlling apparatus, an electrically-driving stirrer, a stirring bar, a nitrogen inlet, a thermocouple, a water-cooling condenser and an addition funnel, and then the temperature was raised up to 120° C. under nitrogen atmosphere. After the epoxy resin 1 and the phosphorus-containing compound HPP had completely dissolved, the reactants were dried under a vacuum. Afterwards, nitrogen was let in and then the container was evacuated again, which was repeated twice. After the temperature of the autoclave was cooled to 85 to 90° C., 6.0 g of triphenylphosphine was added. The epoxy resin and triphenylphosphine were stirred by stirrer, and nitrogen was let in. Then, the mixture was heated up to 160° C. and maintained for 10 minutes. After the reaction had released heat slowly, the temperature was raised up to 180° C. and maintained for 3 hours. Then the phosphorus-containing epoxy resin A was obtained. The theoretical value of the epoxy equivalent weight of the phosphorus-containing epoxy resin A was 582, and the found value was 605; and the theoretical phosphorus content was 2.66 percent by weight. 1035 g of propylene glycol monomethyl ether was added into the obtained phosphorus-containing epoxy resin A to dissolve the phosphorus-containing epoxy resin, and the phosphorus-containing epoxy resin A having 60% solid content was obtained.
Synthesis Example 2
[0074] 300 g of organic cyclic phosphorus-containing compound HCA was charged into a 3000 mL five-neck glass autoclave equipped with an electrically-heating mantle, a temperature-controlling apparatus, an electrically-driving stirrer, a stirring bar, a nitrogen inlet, a thermocouple, a water-cooling condenser and an addition funnel, and then the temperature was raised up to 120° C. under nitrogen atmosphere. After the HCA had completely dissolved, the reactants were dried under a vacuum, then nitrogen was let in and the container was evacuated again, which was repeated twice. After the temperature of the autoclave was cooled to 85 to 90° C., 1000 g of the epoxy resin 2 and 6.0 g of triphenylphosphine was added. The epoxy resin and triphenylphosphine were stirred by stirrer, and let the nitrogen flow in. Then, the mixture is heated up to 160° C. and maintained for 10 minutes. After the reaction had released heat slowly and the temperature was raised up to 180° C. and maintained for 3 hours, the phosphorus-containing epoxy resin B1 was obtained. The value of the epoxy equivalent weight of the phosphorus-containing epoxy resin B1 was 390; and the theoretical phosphorus content was 3.31 percent by weight. 867 g of methyl ethyl ketone was added into the obtained phosphorus-containing epoxy resin B1 to dissolve the phosphorus-containing epoxy resin, and the phosphorus-containing epoxy resin B1 having 60% solid content was obtained.
Synthesis Example 3
[0075] 400 g of organic cyclic phosphorus-containing compound HCA was charged into a 3000 mL five-neck glass autoclave equipped with an electrically-heating mantle, a temperature-controlling apparatus, an electrically-driving stirrer, a stirring bar, a nitrogen inlet, a thermocouple, a water-cooling condenser and an addition funnel, and then the temperature was raised up to 120° C. under nitrogen atmosphere. After the HCA had completely dissolved, the reactants were dried under a vacuum, then nitrogen was let in and then the container was evacuated again, which was repeated twice. After the temperature of the autoclave was cooled to 85 to 90° C., 1000 g of the epoxy resin 2 and 6.0 g of triphenylphosphine were added. The epoxy resin and triphenylphosphine were stirred by stirrer, and nitrogen was let in. Then, the mixture was heated up to 160° C. and maintained for 10 minutes. After the reaction had released heat slowly, the temperature was raised up to 180° C. and maintained for 3 hours. The phosphorus-containing epoxy resin B2 was obtained. The value of the epoxy equivalent weight of the phosphorus-containing epoxy resin B2 was 390; and the theoretical phosphorus content was 4.10 percent by weight. 1400 g of methyl ethyl ketone was added into the obtained phosphorus-containing epoxy resin B2 to dissolve the phosphorus-containing epoxy resin, and the phosphorus-containing epoxy resin B2 having 50% solid content was obtained.
Synthesis Example 4
[0076] 240 g of dianilinemethane, 228 g of phenol, 156.8 g of 92% paraformaldehyde and 300 g toluene were successively charged into a 1 L four-neck reaction vessel equipped with a stirrer, a thermometer, a pressure reducing system, and a condensing-heating mantle. After the reaction system was heated up to 50° C., the electric source for heating was removed. The reaction was conducted for 2.5 hours while maintaining the temperature in the range of 85 and 90° C. after the system released heat . Subsequently, in order to recover toluene, the internal pressure was reduced and the temperature was raised. After reaching 130° C. and more than 650 mm Hg of vacuum pressure, and recovering all of the toluene, the obtained product was dissolved by adding methyl ethyl ketone, and the synthesis resin C having 60% solid content was obtained.
Examples 1 to 4 and Comparative Examples 1 to 2
[0077] Components used in the listed amounts shown in Table 1 are formulated into epoxy resin varnishes in a vessel equipped with a stirrer and a condenser at room temperature.
TABLE 1 Varnishes Comparative Comparative formula Example 1 Example 2 Example 3 Example 4 Example 1 Example 2 Epoxy 240 240 Resin A (g) Epoxy 54 230 313 391 Resin B1 (g) Epoxy 50 252 Resin B2 (g) Synthesis 88 100 133 100 Resin C (g) Hardener A 109 Hardener B 60 Catalyst A 1.0 1.0 0.8 0.63 0.28 0.49 propylene 17 27 25 0 0 0 glycol monomethyl ether
[0078] A glass fiber cloth was impregnated in the phosphorus-containing epoxy resin varnish as formulated above, then dried at 170° C. to obtain prepreg. Eight pieces of the above prepreg were stacked up, and a sheet of 35 μm copper foil was placed on the top and bottom sides of the stack prepregs, then laminated at 200° C. under a pressure of 25 kg/cm 2 to form a laminated entity of the phosphorus-containing epoxy resin and the glass fiber cloths. According to the IPC-TM-650-2.4.25 and IPC-TM-650-2.4.8 standards, the glass transition temperature and the peeling strength of the laminated entities were determined respectively. According to the IPC-TM-650-2.5.17 standard, the surface resistance and the volume resistance were determined. According to the IPC-TM-650-2.5.5.4 standard, the dielectric constant and the dissipation factor were determined. The results are given in Table 2.
TABLE 2 Comparative Comparative Test Item Example 1 Example 2 Example 3 Example 4 Example 1 Example 2 Flame passed passed passed passed passed passed Retardant Test Tg (° C.), TMA 139° C. 141° C. 157° C. 143° C. 127° C. 133.5° C. α 1 of TMA 39 44.2 14.9 82.2 83.7 119 (ppm/° C.) Solder >180 sec. >180 sec. >180 sec. >180 sec. >180 sec. >180 sec. Resistance (288° C.) Peeling 1.2 1.3 1.0 1.0 0.9 0.9 Strength (KN/m)
[0079] From the results in Table 2, it can be seen that the flame retardant properties of the halogen-free resin composition of the invention can meet the UL 94V-0 standard without the addition of halogen-containing components. On the other hand, the halogen-free resin composition of the invention has relatively high heat resistance compared with the resin composition comprising the conventional hardener. | A halogen-free resin composition is provided, comprising: (A) one or more phosphorous-containing epoxy resins; (B) a hardener; and (C) a hardening accelerator, wherein the hardener of component (B) has the structure represented by the following formula (I):
wherein, each symbol is defined as in the specification. The halogen-free resin composition of the present invention has excellent thermal resistance and flame retardant property, and is thereby suitably useful in the application of adhesives, composite materials, laminated plates, printed circuit boards, copper foil adhesives, inks used for build-up process, semiconductor packaging materials, and the like. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. application Ser. No. 14/815,338, filed Jul. 31, 2015, which claims the benefit of U.S. Provisional Application No. 62/031,549, filed on Jul. 31, 2014, hereby incorporated herein in its entirety by reference.
FIELD
[0002] Aspects of the present disclosure relate to crane and/or hoist systems, and in particular to control or augmentation of crane and/or hoist systems.
BACKGROUND
[0003] In some hoisting situations, it is difficult for a crane operator to determine if a crane is directly over the top of a load that is to be moved. In a side load situation, the crane is not directly over the point at which the hook/bottom block is attached to the load. Instead the bottom block may be offset horizontally some amount from its at-rest position. For example, suppose an operator intends to lift a load resting on the ground. If, after attaching the crane's hook to the load, the hook is displaced twelve inches to the side of its at-rest position, then when the operator hoists the load and the load leaves the ground, it may begin to swing. Loads can exceed 100,000 pounds, and can be very large as well. Swinging loads are hazardous because they can cause a number of potential issues, including cable damage creating a risk of cable breakage; damage to the load from impacting surrounding objects; damage to other loads or infrastructure; or injury or death to personnel on the ground hit or crushed by a swinging load.
[0004] If the hook is not correctly positioned over the load prior to hoisting, then the crane operator will often attempt to adjust the position of the crane so that the hook is vertically centered over the load, i.e., the hook is directly over the top of the center of gravity of the load. However, as has been mentioned, it is often difficult for an operator to determine if a hook is directly aligned above the load center. Even a small deviation from center can cause issues such as those described above.
[0005] In some situations, once a load has been moved, the crane is then moved to a different location. If an operator of the crane or ground personnel fail to ensure that the hook is disconnected from the load or the rigging, or fail to notice that the motion of the crane will take the hook into or through an area that has obstacles, a hook can snag. When a hook snags, motion of the hook can become unpredictable, and can lead to damage to the crane, cables, hook, and can cause serious injury or death, especially if the hook snags and drags something heavy or breakable.
SUMMARY
[0006] This Summary and the Abstract herein are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary and the Abstract are not intended to identify key features or essential features of the claimed subject matter, nor are they intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the Background.
[0007] In one embodiment, a method of augmenting a lifting operation for a crane includes detecting a side load condition for a load to be moved by the crane, and preventing a hoist operation when the side load condition is detected.
[0008] In another embodiment, a method of snag detection for a load to be moved with a crane includes monitoring an angular deflection of the load with respect to an at-rest position of the load, and halting movement of the crane in a direction that results in an increasing angular deflection.
[0009] In another embodiment, a method of auto-centering a load to be moved with a crane includes determining a position of a block coupled to the load with respect to a trolley of the crane, and centering the trolley over the block prior to a moving operation. Centering includes in one embodiment comparing a position of a fiducial marker associated with the block using a camera associated with the trolley to a known centered position of the fiducial marker with respect to the camera, and moving the trolley to match the determined position of the fiducial marker to the known centered position of the fiducial marker.
[0010] In another embodiment, a crane motion detection system includes a camera configured to mount on a trolley of the crane, a fiducial marker configured to mount on a hook of the crane within a field of view of the camera, and a controller coupled to the camera to receive and process images from the camera, and coupled to the trolley to control operation of the trolley in response to processed images. The controller in one embodiment controls operation to at least one of detecting and preventing off center lifts of a load, detecting and preventing snagging of a load, and auto-centering the crane over a load as described in other embodiments herein.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a diagrammatic view of a crane and motion control system according to an embodiment of the present disclosure;
[0012] FIG. 2 is a top view of a portion of a bottom block of FIG. 1 ;
[0013] FIG. 3 is a block diagram of a controller according to an embodiment of the present disclosure;
[0014] FIG. 4 is a representative view of a camera image according to an embodiment of the present disclosure;
[0015] FIGS. 5A and 5B are diagrammatic views of a crane with bottom block in at-rest and angularly displaced configurations;
[0016] FIG. 6 is a representative view of a camera image according to another embodiment of the present disclosure;
[0017] FIG. 7 is a representative view of a camera image according to another embodiment of the present disclosure; and
[0018] FIG. 8 is a schematic view of a controller on which embodiments of the present disclosure may be practiced.
DETAILED DESCRIPTION
[0019] Embodiments of the present disclosure provide motion control systems for industrial cranes including, for example only and not by way of limitation, heavy equipment production cranes, primary metals coil cranes, general purpose single and double girder bridge cranes, and the like. Side load detection, auto load centering, and snag detection are some of the motion controls provided by embodiments of the present disclosure.
[0020] Camera-based crane manipulation and control may increase safety and may simplify hoisting tasks. Embodiments of the disclosure include a camera mounted to a crane in a position to be able to image a fiducial marker having a fiducial pattern thereon that is mounted to a hook/bottom block of the crane in a position so as to be visible in the field of view of the camera. With the image of the hook/bottom block of the crane, a controller, such as a programmable logic controller (PLC) is used to interpret data from the image to detect and in some cases correct issues with crane loading. Such issues include by way of example only and not by way of limitation, side load detection, auto load centering, and snag detection. In general, adverse cable angles may be detected against a threshold, such as an angular deflection of a fixed value, a hoist length, a distance of the block from an image capture element mounted on a trolley of the crane, or the like. A control response may be initiated, or a warning may be issued, following the detection.
[0021] Sensory information about hook position is obtained using the camera, such as an industrial machine vision digital camera in one embodiment, together with software, firmware and/or hardware such as a programmable logic controller (PLC) to control operation of a crane, specifically, of the motion of a crane. The camera is in one embodiment mounted on a crane trolley, near a cable drum, oriented downward toward a typical at-rest position for the hook. In this configuration, the hook is visible to the camera. The camera captures and analyzes in one embodiment 20 images of the hook including the fiducial marker per second. Hook position information is determined by the controller using the images and known functions relating to the fiducial marker, as described further below. In this disclosure, the terms hook and bottom block may be used interchangeably, as known in the field.
[0022] To facilitate reliable hook tracking, in one embodiment, the fiducial marker comprises a pattern of retro-reflective fiducial markers fastened to the hook. Fiducial markers are easily discernable from the other features in the workspace. They permit the camera to track the hook consistently and accurately. While retro-reflective fiducial markers are described herein, it should be understood that any fiducial marker capable of being imaged by the camera is amenable to use with the embodiments of the present disclosure without departing from the scope of the disclosure.
[0023] Embodiments of the present disclosure mount an industrial camera to a crane, mount fiducial markers on a bottom block or hook of the crane within the field of view of the camera, and determine with a controller an angular or horizontal displacement of the hook from its at-rest position, using images taken by the camera of the fiducial markers. With that information, the controller may be used in some embodiments to implement control restrictions on the crane or implement crane movement to correct the angular displacement, or issue warning(s) to the crane operator.
[0024] Referring to FIG. 1 , a diagrammatic view of a crane 100 is shown. Crane 100 is shown generally, but it should be understood that crane 100 can comprise any number of overhead crane types such as single and double girder bridge cranes, and the like. Crane 100 comprises in one embodiment crane body 102 which can comprise a set of parallel runways with a traveling bridge spanning the gap and movable in a direction parallel with the runways, and a trolley movable laterally along the bridge (i.e., perpendicular to the runways), or the like, as are known in the art. A hoist 103 travels along the trolley, and supports a bottom block 104 and hook 106 using cabling 108 . The crane 100 is used to hoist or move a load 110 rigged to the hook 106 through rigging 112 , such as cables or the like. An imaging system 114 (in one embodiment a digital camera such as an industrial machine vision camera or the like) is mounted to the crane body 102 (such as to the trolley or hoist 103 ) in a position so as to place fiducial marker 116 , which is mounted to the bottom block 104 or hook 106 , visible in its image field of view.
[0025] Fiducial marker 116 in one embodiment comprises a fiducial with a plurality of retro-reflective fiducial markers 202 thereon, as shown in top view in FIG. 2 . Retro-reflective marker 116 is shown mounted to a top surface 117 of bottom block 104 . However, it should be understood that retro-reflective marker 116 may be mounted in a different position on the bottom block 104 or to the hook 106 , provided that it is visible to the field of view of camera 114 . Also, camera 114 may be mounted in a different position on the crane body 102 so long as the retro-reflective marker 116 is visible in the field of view of the camera 114 during operation. Although a series of six round retro-reflective fiducial markers 202 arranged in a particular pattern are shown, it should be understood that different fiducial patterns or quantity of fiducials may be used in embodiments of the present disclosure without departing from the scope of the disclosure.
[0026] Referring also to FIG. 3 , camera 114 is connected in one embodiment to a controller 300 that analyzes images from the camera 114 to determine position of the hook 106 and/or bottom block 104 . In another embodiment, the camera includes processing power sufficient to analyze the images to determine position of the hook, and reports this result to the controller. In this embodiment, the camera is a “smart” camera. It has image taking capabilities and image processing capabilities. The results of the processing are issued to the PLC. In an at-rest position, that is, with the bottom block and hook in a substantially static position free hanging on the cables 108 from the crane body 102 , the camera 114 takes an image including the retro-reflective marker 116 , and conveys the image to the controller 300 , or processes the image itself. Controller 300 or camera determines the position of the bottom block 104 and hook 106 relative to its at-rest position by determining the position of the retro-reflective marker 116 relative to its at-rest position (see below). Position parameters include in some embodiments position within the field of view of the camera 114 and/or a distance of the bottom block 104 or hook 106 from the camera 114 , and may be determined as described below. Communication between camera 114 , controller 300 , and crane controls 120 at operator location 118 may be accomplished over one or more of a number of connections, including by way of example only and not by way of limitation, wired connections, wireless connections, or a combination thereof.
[0027] Referring now also to FIG. 4 , in one embodiment, this determination of position of the retro-reflective marker 116 is made using an image 400 provided to the controller 300 . As is seen in FIG. 4 , image 400 occupies a specific area 402 , which may be a display or portion of a display, or any known dimension area (such as a number of pixels wide and a number of pixels deep, or the like). The centroid location 412 of the fiducial markers 202 on retro-reflective marker 116 may be expressed with respect to the image 400 as a particular number of pixels 404 from a top edge 405 of the image 400 , and a particular number of pixels 406 from a right side edge 407 of the image 400 . The location of the bottom block 104 in one embodiment may therefore be determined by reference to the number of pixels 404 and 406 , and a centroid 412 of the retro-reflective marker 116 may also be determined. The centroid will have a coordinate of 404 , 406 as determined from the top 405 and right 407 of the image 400 which constitutes the field of view of the camera 114 . It should be understood that the coordinates may be with respect to any point within the field of view of the camera 114 , and can be expressed in a number of different units other than pixels as described herein, as embodied in the image without departing from the scope of the disclosure.
[0028] Normally, operations of a crane such as crane 100 are controlled by an operator in a cab or operator location 118 using controls 120 (simplified for purposes of this disclosure). The crane operator uses the controls 120 to perform operations including hoist operations, traverse operations, and the like, as are known in the art. Typically, an operator and another person or persons responsible for a load on the crane work in combination to rig the load in preparation for crane operations. Rigging can be difficult, especially for very large loads, or for loads that are not uniform or symmetric. Despite experience and skill of riggers and crane operators, nevertheless, loads can be improperly rigged, leading to potentially very dangerous situations in which loads can shift, be side pulled, tip, or the like.
[0029] For example, when bottom block 104 (and hook 106 ) are coupled to a load such as load 110 as shown in FIG. 1 , a condition known as side-loading may occur. Side-loading can lead to side pull lifts, which can cause serious consequences for loads, cranes, and personnel, as described above. An example of a side loading condition is shown in diagrammatic form in FIGS. 5A and 5B . A rest position of a bottom block 104 coupled to crane body 102 with cables 108 is shown in dashed lines, and a side loaded position of bottom block 104 coupled to crane body 102 with cables 108 is shown in solid lines. As may be seen, the bottom block 104 is displaced from its at-rest position by an angle α with respect to its at-rest position. A determination of this side-load angle α may be made in one embodiment using an image (such as image 400 ) of the bottom block 104 in its rest position versus an image of the bottom block 104 in its current position, that is, a position in which the crane 100 is ready for a hoist operation (as shown in FIG. 6 ).
[0030] Referring now also to FIG. 6 , representative image 600 including bottom block 104 and its retro-reflective marker 116 in a side-loaded position such as that shown in FIG. 5 and taken by a camera such as camera 114 is shown. In the image 600 , retro-reflective marker 116 is in a different position than its at-rest position as shown in FIG. 4 . The bottom block 104 and consequently the retro-reflective marker 116 have moved from their at-rest positions by a distance in the x-direction by an amount of pixels 604 and in the y-direction by an amount of pixels 606 . The centroid position 412 ′ of the bottom block 104 and retro-reflective marker 116 is determined in this embodiment again using the fiducial markers 202 . The centroid location 412 ′ of the fiducial markers 202 on retro-reflective marker 116 may be expressed with respect to the image 600 as a particular number of pixels 404 ′ from a top edge 405 of the image 600 , and a particular number of pixels 406 ′ from a right side edge 407 of the image 600 . The location of the bottom block 104 in one embodiment may therefore be determined by reference to the number of pixels 404 ′ and 406 ′, and a centroid 412 ′ of the retro-reflective marker 116 may also be determined. The centroid 412 ′ will have a coordinate of 404 , 406 as determined from the top 405 and right 407 of the image 600 which constitutes the field of view of the camera 114 . The bottom block 104 is therefore side-loaded in FIG. 6 by an amount that may be determined using the images 600 and 400 , by determining the distance 612 in pixels between the centroid locations 412 and 412 ′. Based on the camera lens and camera characteristics, a simple conversion between a number of pixels and an angle is used to determine the angle α between the centroid positions 412 and 412 ′.
[0031] In one embodiment, when the controller 300 determines that a load (such as load 110 ) on the hook is side-loaded by an angle greater than a determined, settable and adjustable threshold, the controller 300 disallows any hoisting operation. That is, even if a crane operator uses the controls 120 to initiate a hoist operation, the controller 300 disables the hoisting operation. In one embodiment, a signal is sent from the controller 300 to crane controls 120 that disables the hoisting operation. Hoisting operation may be re-enabled when the side-loading is corrected to an angle below the threshold. The threshold angle of acceptable side-loading may be set based on the load, the crane, the conditions, or some combination thereof.
[0032] When camera 114 captures an image of the bottom block 104 in its field of view, the image may be transmitted to the controller 300 , and the controller 300 uses that image, along with the known function and base images of the bottom block 104 in its at-rest position for the distance between the camera 114 and the bottom block 104 (described in detail below), to determine an angular displacement of the bottom block 104 from its at-rest position. Alternatively, the camera may capture the image and process it internally to determine the current angular displacement. Then, this value is transmitted to the controller. The angular displacement threshold at which hoisting is prevented may be in one embodiment a function of one or more of the load characteristics and the distance between the camera and the bottom block. In one embodiment, when the bottom block 104 is higher, that is, when the distance between the camera 114 and the bottom block 104 is smaller, the allowable angular displacement may be larger than when the distance between the camera 114 and the bottom block 104 is larger. In one embodiment, the controller 300 is programmed to determine the distance between the camera 114 and the bottom block 104 (described below with reference to FIG. 7 ) and consult a table of the threshold angle α of angular displacement allowed before preventing hoisting operations.
[0033] Referring again to FIGS. 4 and 6 , one embodiment of the present disclosure provides for auto-centering of a load. Side load hoisting prevention is concerned with preventing a hoisting operation if there is a side-loading exceeding a certain predetermined angle. Auto-centering uses images of a bottom block 104 and hook 106 in an at-rest position (as shown at 400 in FIG. 4 ) and of the bottom block 104 and hook 106 in a loaded condition potentially ready for hoisting (as shown at 600 in FIG. 6 ) to adjust the position of the bottom block 104 and hook 106 to place the bottom block 104 and hook 106 in the at-rest position of the bottom block 104 and hook 106 before operation. This may be done automatically by an operator engaging auto-centering such as by selection of auto-centering via controls 120 . In another embodiment, auto-centering may be set to activate when a hoisting operation is initiated by an operator.
[0034] To accomplish this, the component pixel distances used for determining an angle α of side-loading may be used for auto-centering. Specifically, FIG. 4 shows an image 400 of a bottom block 104 and the retro-reflective marker 116 thereon. The centroid 412 of the fiducial markers 202 of the retro-reflective marker 116 is identified as a number of pixels 404 from a top 405 of the image 400 and a number of pixels 406 from a right side 407 of the image 400 . FIG. 6 shows an image 600 of the bottom block 104 and retro-reflective marker 116 thereon. The centroid of the fiducial markers 202 of the retro-reflective marker 116 has moved, and is now at a centroid location identified as 412 ′ which is a number of pixels 404 ′ from a top 405 of the image 600 and a number of pixels 406 ′ from a right edge 407 of the image 600 . This correlates to a difference of a number of pixels 604 in the x-direction and a number of pixels 606 in the y-direction, as indicated by the axis legend of the figures. As the speed of current cameras allows for imaging at a speed of at least 20 frames per second, corrective movement can be made essentially in real time, as follows.
[0035] If the bottom block 104 is off center with respect to its at-rest position in either or both of the x- or y-directions beyond a certain threshold, in an auto-centering operation, the crane 100 automatically moves the bottom block 104 to center the bottom block 104 on its at-rest position. Movement of the crane provides independent movement in each of the x- and y-directions. In one embodiment, the controller 300 determines the number of pixels 604 from the at-rest position the bottom block 104 is in the x-direction, and determines the number of pixels 606 from the at-rest position the bottom block 104 is in the y-direction, and initiates movement of the crane toward the at-rest position in each of the x- and y-directions. To move the bottom block 104 toward its at-rest position in one embodiment, the controller 300 initiates control of the crane to move the bottom block 104 toward its at-rest position in the x-direction, and initiates control of the crane to move the bottom block 104 toward its at-rest position in the y-direction. In one embodiment, the movement of the crane is at its minimum speed to avoid, or at a speed suitable to prevent or reduce, unnecessary oscillation or swaying (i.e., overshoot) of the bottom block 104 and hook 106 . For each axis of motion, in this embodiment along the x-direction of movement and along the y-direction of movement, the pixel difference between the off-center position (as shown in image 600 ) and the at-rest position (as shown in image 400 ) is determined by subsequent images in the same fashion as described above. Once the displacement of the bottom block 104 changes sign on a particular axis, motion in that direction is stopped by the controller 300 . Additionally, motion may also be stopped when the angular displacement is less than a predetermined, settable amount, or when auto-centering has been active for a specified duration.
[0036] One corrective motion for each axis is used in one embodiment so as to avoid potential oscillation of the bottom block 104 and hook 106 that might be caused by multiple corrections or continuous corrections. One motion is enabled as follows. Once a position 404 ′, 406 ′ is determined, motion toward the at-rest position 404 , 406 is initiated in auto-centering. In the x-direction, a number of pixels 604 is the difference between 404 ′ and 404 . Movement of the crane in the x-direction is performed while the controller monitors the current position with respect to the at-rest position. As the determined difference 604 between 404 ′ and 404 shrinks, it eventually gets to 0 and then to −1 pixel. At this point, the displacement is considered to have changed signs, and motion on the x-axis is stopped. The same operation occurs for the corrective motion in the y-direction. Corrective action along the axes is independent. Alternatively, auto-centering is stopped in another embodiment when the angle is less than a specified threshold for a finite duration, or if auto-centering action has been active for a specified duration. This is especially useful in systems where the angle may not change sign. These methods may be implemented independently or simultaneously.
[0037] Oscillation may also be induced when motion of the crane is at a variable speed, such as proportional control. In a proportional control scheme, a high velocity is used at a start of a corrective motion, and as the distance to be corrected decreases, the speed of motion also decrease. Embodiments of the present disclosure may use proportional control for corrective motion, but motion at a constant minimum speed of the crane with only one corrective motion per axis is used in one embodiment. If more than one corrective motion is used, that may induce limit cycling and constant correction that may make a situation worse.
[0038] A distance from the camera 114 to the retro-reflective marker 116 may be determined in one embodiment without distance sensors using a known distance function determined by a size of the retro-reflective marker at various known distances from the camera such as may be determined in calibration of the camera. A closed form function may be determined allowing the controller 300 to determine where in the field of view of the camera the at-rest position of the bottom block 104 is for all distances from the camera 114 to the bottom block 104 .
[0039] For example, the closer the retro-reflective marker 116 is to the camera, the larger it appears in an image taken by the camera. So, once the function of distance from the camera 114 to retro-reflective marker 116 is determined, the controller 300 simply determines the size of the retro-reflective marker 116 , compares it to the function or known size parameters, and determines the distance of the retro-reflective marker 116 from the camera 114 . From that distance, the at-rest position for the hook is known at any distance from the camera 114 , without using distance sensors. In another embodiment, a hoist length sensor may be used. In such a configuration, hoist length data from the hoist length sensor may be used directly with the closed form functions for determining the at-rest position of the hook.
[0040] Referring now also to FIG. 7 , an image 700 is shown. Image 700 has retro-reflective marker 116 shown. In this image 700 , retro-reflective marker 116 is larger in the field of view of the camera 114 than the image of the retro-reflective marker 116 in the field of view of the camera 114 shown in FIG. 4 . A measurable dimension of the retro-reflective marker 116 is made for each image. For example, in FIG. 4 , a dimension 408 and a distance 410 are determined with respect to specific identifiable individual fiducials 202 . The same dimensions with respect to the same fiducials 202 are also measured in FIG. 7 as dimensions 408 ′ and 410 ′. Given the known distance function, the distance of the camera 114 from the retro-reflective marker 116 may be determined by the size of the fiducial.
[0041] One embodiment of the present disclosure determines when a snag condition occurs. A snag condition may occur, as described above, when a hook catches on a load, an obstruction of some sort, infrastructure, rigging, or the like, or when the hook is not fully disconnected from a load that has been moved, for example. In a snag detection operation, embodiments of the present disclosure determine, based on a comparison in the controller 300 of images of the bottom block 104 in its at-rest position to its current position, whether a traverse operation of the crane is displacing the hook 106 from its at-rest position by more than a particular angular displacement. In snag detection, once a difference in position between the at-rest position and the current position of the hook 106 exceeds a certain, settable, angle, traverse motion of the crane in the direction of motion that increases the angular deflection is stopped by the controller. Movement to alleviate the snag, that is, in the direction of motion that decreases the angular deflection, is still allowed. In another embodiment, the controller 300 may, using known functions, determine a velocity or acceleration of displacement from an at-rest position to identify a snag or potential snag condition. In one embodiment, the controller 300 issues an emergency stop command to the crane when a snag condition is detected. Then, once the crane has stopped motion, correction of the snag may be initiated.
[0042] Snag detection operation can mitigate but not necessarily completely eliminate hazards associated with snagging, and cannot in all instances prevent a snag. This is, in part, because whether a load is dragged and causes damage depends on a number of factors including but not limited to load height, mass, capability of drives and brakes on the crane, how heavy crane is, and the like.
[0043] While a bottom block and hook are shown in the various figures, it should be understood that additional hoisting devices such as magnets, balls, and the like known in the art are amenable for use with the embodiments described herein without departing from the scope of the disclosure.
[0044] Embodiments of the present disclosure are compatible with existing variable frequency drives for cranes. Enabling and disabling embodiments of the present disclosure may be accomplished with existing wired or radio pendants. Embodiments of the present disclosure are configured to be retrofitted onto existing hardware platforms, including but not limited to heavy equipment production cranes, primary metals coil cranes, and general purpose single & double girder bridge cranes. Embodiments of the present disclosure may be used in standalone form, or in conjunction with other crane control technology, for example only and not by way of limitation, with Expertoperator™, Safemove™, and Automove™ offered by PaR Systems of Shoreview, Minn.
[0045] The system controller such as PLC 300 shown in FIG. 3 and usable on all the hoist systems herein described can comprise a digital and/or analog computer. The logic to implement the control features can be implemented on a PLC with an appropriate input/output configuration. FIG. 8 and the related discussion provide a brief, general description of a suitable computing environment in which the system controller 300 can be implemented. Although not required, the system controller 300 can be implemented at least in part, in the general context of computer-executable instructions, such as program modules, being executed by a computer 370 . Generally, program modules include routine programs, objects, components, data structures, etc., which perform particular tasks or implement particular abstract data types. Those skilled in the art can implement the description herein as computer-executable instructions storable on a computer readable medium. Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including multi-processor systems, networked personal computers, mini computers, main frame computers, and the like. Aspects of the invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computer environment, program modules may be located in both local and remote memory storage devices.
[0046] The computer 370 comprises a conventional computer having a central processing unit (CPU) 372 , memory 374 and a system bus 376 , which couples various system components, including memory 374 to the CPU 372 . The system bus 376 may be any of several types of bus structures including a memory bus or a memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The memory 374 includes read only memory (ROM) and random access memory (RAM). A basic input/output (BIOS) containing the basic routine that helps to transfer information between elements within the computer 370 , such as during start-up, is stored in ROM. Storage devices 378 , such as a hard disk, a floppy disk drive, an optical disk drive, etc., are coupled to the system bus 376 and are used for storage of programs and data. It should be appreciated by those skilled in the art that other types of computer readable media that are accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, random access memories, read only memories, and the like, may also be used as storage devices. Commonly, programs are loaded into memory 374 from at least one of the storage devices 378 with or without accompanying data.
[0047] Input devices such as a keyboard 380 and/or pointing device (e.g. mouse, joystick(s)) 382 , or the like, allow the user to provide commands to the computer 370 . A monitor 384 or other type of output device can be further connected to the system bus 176 via a suitable interface and can provide feedback to the user. If the monitor 384 is a touch screen, the pointing device 382 can be incorporated therewith. The monitor 384 and input pointing device 382 such as mouse together with corresponding software drivers can form a graphical user interface (GUI) 386 for computer 370 . Interfaces 388 on the system controller 300 allow communication to other computer systems if necessary. Interfaces 388 also represent circuitry used to send signals to or receive signals from the actuators and/or sensing devices mentioned above. Commonly, such circuitry comprises digital-to-analog (D/A) and analog-to-digital (A/D) converters as is well known in the art.
[0048] Without limitation, some aspects of the disclosure include, snag detection, auto-centering, and hoist prevention on side loading. Further aspects include a crane motion detection system comprising a camera, a fiducial marker, and a controller to process images from the camera to control operation of a crane in side-loading, snagging, and auto-centering situations; and a controller aspect configured to execute computer executable instructions for performing methods of snag detection, auto-centering and side load detection as shown and described herein.
[0049] Although the subject matter has been described in language directed to specific environments, structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the environments, specific features or acts described above as has been held by the courts. Rather, the environments, specific features and acts described above are disclosed as example forms of implementing the claims. | Methods of detection and prevention for snags or off center lifts, and auto-centering a crane over a load. Snag detection includes monitoring angular deflection of the load with respect to an at-rest position, and halting movement of the crane in a direction of increasing angular deflection. Controlling off center lifting includes detecting a side load condition for a load, and preventing a hoist operation when the side load condition is detected. Auto-centering a load includes determining a position of a block coupled to the load with respect to a trolley of the crane, and centering the trolley over the block prior to a moving operation. Centering includes comparing a position of a block marker using a trolley camera to a known centered position of the marker with respect to the camera, and moving the trolley to match the determined position of the marker to its known centered position. | 1 |
[0001] The present application is a continuation-in-part of commonly-assigned U.S. patent application Ser. No. 09/312,917, “Reflective LCD Projection System Using Wide-Angle Cartesian Polarizing Beam Splitter,” filed on May 15, 1999, which is hereby incorporated by reference. The present application also claims priority from commonly assigned U.S. Provisional Application No. 60/178,973 entitled “Reflective LCD Projection System Using Wide-Angle Cartesian Polarizing Beam Splitter And Color Separation And Recombination Prisms”, filed Jan. 26, 2000, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to the use of 3M Cartesian polarizing beam splitter (PBS) films to make electronic projection systems that use color separation and recombination prisms (e.g. Philips Prisms) with very efficient, low f/# optical beams while preserving high contrast. More specifically, the present invention relates to an optical imaging system including a reflective imager and a Cartesian wide-angle polarizing beam splitter (“PBS”) having a fixed polarization axis and using the tilted reflective surfaces of a Philips prism.
[0003] Optical imaging systems may include a transmissive or a reflective imager or light valve. Traditional transmissive light valves allow certain portions of a light beam to pass through the light valve to form an image. By their very function, transmissive light valves are translucent; they allow light to pass through them only where required electrical conductors and circuits are not present. Reflective Liquid Crystal on Silicon (LCOS) imagers, in turn, reflect selected portions of the input beam to form an image. Reflective light valves provide important advantages, as controlling circuitry may be placed below the reflective surface, so that these circuits do not block portions of the light beam as in the transmissive case. In addition, more advanced integrated circuit technology becomes available when the substrate materials are not limited by their opaqueness. New potentially inexpensive and compact liquid color display (LCD) projector configurations may become possible by the use of reflective LC microdisplays. Reflective Liquid Crystal on Silicon (LCOS) imagers in the past have been incorporated into inefficient, bulky and expensive optical systems.
[0004] For projection systems based on reflective LCD imagers, a folded light path wherein the illuminating beam and projected image share the same physical space between a polarizing beam splitter (PBS) and the imager offers a desirably compact arrangement. A PBS is an optical component that splits incident light rays into a first polarization component and a second polarization component. Traditional PBS's selectively reflect or transmit light depending on whether the light is polarized parallel or perpendicular to the plane of incidence of the light: that is, a plane defined by the incident light ray and a normal to the polarizing surface. The plane of incidence also is referred to as the reflection plane, defined by the reflected light ray and a normal to the reflecting surface.
[0005] Based on the operation of traditional polarizers, light has been described as having two polarization components, a p-component or direction and a s-component or direction. The p-component corresponds to light polarized parallel to the plane of incidence. The s-component corresponds to light polarized perpendicular to the plane of incidence. A so-called MacNeille PBS will substantially reflect s polarized light incident on the PBS surface (placed along the diagonal plane connecting two opposing edges of a rectangular glass prism), and substantially transmit p polarized light incident upon this surface. Traditional MacNielle PBS technology, is known, and is described in, for example, U.S. Pat. No. 2,403,731; H. A. Macleod, Thin Film Optical Filters, 2 nd Edition, McGraw-Hill Publishing Co., 1989; pp. 328-332.
[0006] To achieve the maximum possible efficiency in an optical imaging system, a low f/# system is desirable (see, F. E. Doany et al., Projection display throughput; Efficiency of optical transmission and light-source collection, IBM J. Res. Develop. V42, May/July 1998, pp. 387-398). The f/# measures the light gathering ability of an optical lens and is defined as:
f/#=f (focal length)÷D (diameter or clear aperture of the lens)
[0007] The f/# (or F) measures the size of the cone of light that may be used to illuminate an optical element. The lower the f/#, the faster the lens and the larger the cone of light that may be used with that optical element. A larger cone of light generally translates to higher light throughput. Accordingly, a faster (lower f/#) illumination system requires a PBS able to accept light rays having a wider range of incident angles.
[0008] The maximum incident angle θmax (the outer rays of the cone of light) may be mathematically derived from the f/#, F:
θ max =tan −1 ((2 F ) −1 )
[0009] Traditional folded light path optical imaging systems have employed the previously described optical element know as a MacNeille PBS. MacNeille PBS's take advantage of the fact that an angle exists, called Brewster's angle, at which no p-polarized light is reflected from an interface between two media of differing index. Brewster's angle is given by:
θ B =tan −1 ( n 1 /n 0 ),
[0010] where n 0 is the index of one medium, and n 1 is the index of the other. When the angle of incidence of an incident light ray reaches the Brewster angle, the reflected beam portion is polarized in the plane perpendicular to the plane of incidence. The transmitted beam portion becomes preferentially (but not completely) polarized in the plane parallel to the plane of incidence. In order to achieve efficient reflection of s-polarized light, a MacNeille polarizer is constructed from multiple layers of thin films of materials meeting the Brewster angle condition for the desired angle. The film thicknesses are chosen such that the film layer pairs form a quarter wave stack.
[0011] There is an advantage to this construction in that the Brewster angle condition is not dependent on wavelength (except for dispersion in the materials). However, MacNeille PBS's have difficulty achieving wide-angle performance due to the fact that the Brewster angle condition for a pair of materials is strictly met at only one angle of incidence. As the angle of incidence deviates from this angle a spectrally non-uniform leak develops. This leak becomes especially severe as the angle of incidence on the film stack becomes more normal than the Brewster's angle. As will be explained below, there are also contrast disadvantages for a folded light path projector associated with the use of p and s-polarization, referenced to the plane of reflection for each ray.
[0012] Typically, MacNeille PBS's are contained in glass cubes, wherein a PBS thin-film stack is applied along a diagonal plane of the cube. By suitably selecting the index of the glass in the cube, the PBS may be constructed so that light incident normal to the face of the cube is incident at the Brewster angle of the PBS.
[0013] MacNeille-type PBSs reportedly have been developed capable of discrimination between s- and p-polarized light at f/#'s as low as f/2.5, while providing extinction levels in excess of 100:1 between incident beams of pure s or pure p polarization. Unfortunately, as explained below, when MacNeille-type PBSs are used in a folded light path with reflective imagers, the contrast is degraded due to depolarization of rays of light having a reflection plane rotated relative to the reflection plane of the central ray. As used below, the term “depolarization” is meant to describe the deviation of the polarization state of a light ray from that of the central light ray. As light in a projection system generally is projected as a cone, most of the rays of light are not perfectly parallel to the central light ray. The depolarization increases as the f/# decreases, and is magnified in subsequent reflections from color selective films. This “depolarization cascade” has been calculated by some optical imaging system designers to effectively limit the f/# of MacNeille PBS based projectors to about 3.3, thereby limiting the light throughput efficiency of these systems. See, A. E. Rosenbluth et al., Contrast properties of reflective liquid crystal light valves in projection displays, IBM J. Res. Develop. V42, May/July 1998, pp. 359-386, (hereinafter “ Rosenbluth Contrast Properties ”) relevant portions of which are hereby incorporated by reference.
[0014] Recently, Minnesota Mining and Manufacturing has developed a novel type of birefringent polymeric multi-layer polarizing film (“3M advanced polarizing film” or “APF”). Co-assigned and co-pending parent application U.S. patent application Ser. No. 09/312,917, describes the use of such a film as a polarizing beam splitter. European Patent Application EP 0 837 351 A2 attempts to utilize another 3M dual brightness enhancing film (DBEF), an early 3M multi-layer film material, in a projection display apparatus having a “wide angle” reflecting polarizer. Such reference refers to p and s differentiation and uses the 3M material as a common reflective polarizer. Moreover, while “wide-angle” performance is a widely recognized design goal, references to “wide-angle” are meaningless absent contrast limits and spectral leak reduction and teachings on how to achieve such a goal. The 3M product “DBEF” is a reflective polarizer with typical block direction leakages of 4 to 6 percent at normal incidence. At higher angles the leakage is somewhat reduced, but at 45 degrees the extinction is typically still a few percent. Contrast ratios when using DBEF typically will be limited to maximum values at or below 99:1 for white light. However, DBEF suffers from spectral leaks that reduce the contrast of certain color bands to as low as 25:1, depending on the nature of the illumination source and the exact DBEF sample. To obtain superior performance it is desirable that good screen uniformity and the absence of spectral leaks in the dark state accompany good average contrast in all relevant color bands.
[0015] There has been previous work with non-telecentric configuration, reported by Paul M. Alt in the Conference Record of the 1997 International Display Research Conference (p. M 19-28) and in the IBM Journal of Research and Development (Vol. 42, pp. 315-320, 1998). These systems, however, used conventional MacNeille PBS cubes rather than a Cartesian PBS, and achieved a contrast ratio of only 40:1 at f/5. The PBS and the color prism were used in an s-orientation.
[0016] The need remains for an optical imaging system that includes truly wide angle, fast optical components and that may allow viewing or display of high-contrast images. Furthermore, it is desirable to enable optical designs that minimize the size of individual components, such as the color separation prism.
[0017] A color separation prism receives the polarized beam of light and splits the beam, generally into three-color components. Color prisms and imagers naturally have an orientation, including a long axis and a short axis. Optical designers are presently constrained to one of two options. The first is to place the imager on the color prism such that the long axis of the imager is parallel to the long axis of the color prism exit aperture (to the imagers). This allows the use of the smallest possible color prism, but under this condition, if the tilt axes of the PBS and the color prism are kept parallel to each other, then the designer is constrained to build the projector in a tower configuration. Such a configuration places the longest dimension of the projector in a vertical orientation, which may be unsuitable for a variety of applications. The second option is to place the long axis of the imager along the short direction of the color prism exit aperture (to the imagers). This allows the use of more desirable low-profile projector configurations, wherein the longest dimension of the projector is horizontal. However, this requires that the color prism be made larger and therefore that the projection lens have a longer back focal length. Consequently, this configuration will require larger, heavier, and more expensive projection lens and color prism components.
SUMMARY OF THE INVENTION
[0018] The present invention describes an optical imaging system including and advantageously employing a wide-angle “Cartesian” polarizer beam splitter (“PBS”) and a Philips prism for separating and recombining separate color bands. The optical imaging system of the present invention is capable for use with “fast” (low f/#) optical beams while providing a high contrast ratio. The term optical imaging system is meant to include front and rear projection systems, projection displays, head-mounted displays, virtual viewers, head up displays, optical computing, optical correlation and other similar optical viewing and display systems. A Cartesian PBS is defined as a PBS in which the polarization of separate beams is referenced to invariant, generally orthogonal principal axes of the PBS. In contrast with a MacNeille PBS, in a Cartesian PBS the polarization of the separate beams is substantially independent of the angle of incidence of the beams. The use of a Cartesian PBS film also allows the development of systems using curved PBS that provide higher light output and/or replace or augment other optical components.
[0019] A wide-angle PBS is defined as a PBS capable of receiving a cone of light rays with an angle of incidence up to 11° (in air) or more, while maintaining acceptable system contrast. By recognizing and advantageously applying properties of wide-angle Cartesian polarizers, the present invention discloses a high-efficiency optical imaging system capable of functioning at f/#'s equal to or below f/2.5 while maintaining a contrast ratio of at least 100 to 1, or, more preferably, 150 to 1 in a projection system configuration.
[0020] An embodiment of an optical imaging system in accordance with the present invention includes a wide-angle Cartesian polarizing beam splitter, light valve illumination optics having an f/#≦2.5, a color separation and recombination prism and at least two reflective light valves. The Cartesian polarizing beam splitter (PBS) has a structural orientation defining fixed polarization axes. A reflective Cartesian PBS substantially reflects those components of a beam of light that are polarized along one such fixed axis, called the Material Axis. Those components of a beam of light with polarization not along the Material Axis are substantially transmitted. The polarizing beam splitter therefore splits incident light into a first and a second substantially polarized beam having polarization states referenced to the fixed polarization axes and the polarizing beam splitter directs the first polarized beam onto the reflective light valve. In an exemplary embodiment, the Cartesian PBS includes 3M advanced film. In other exemplary embodiments, the PBS may include a wire grid polarizer, such as those described in Schnabel et al., “ Study on Polarizing Visible Light by Subwavelength - Period Metal - Stripe Gratings ”, Optical Engineering 38(2), pp. 220-226, February 1999, relevant portions of which are hereby included by reference. Other suitable Cartesian polarizers also may be employed.
[0021] The light valve illumination optics have an f/# of at most 2.5, a minimum cone angle of about 11 degrees (in air) and the system has a contrast ratio exceeding 100 to 1 using an ideal imager. In preferred embodiments, the contrast ratio exceeds 150 to 1 and the illumination optics have an f/# equal or less than 2.2. The illumination optics are those optics that condition (e.g., prepolarize, shape, homogenize and filter) the light beam. The f/# is associated with the beam of light incident on the imager.
[0022] The light valves or imagers may be a polarization modulating light valve, including smectic or nematic liquid crystal light valves. The optical imaging system may further comprise a pre-polarizer that polarizes input light into pre-polarized light, the pre-polarized light comprising the incident light on the polarizing beam splitter. The optical imaging system also includes a color separation and recombination prism assembly or mirrors and a plurality of reflective light valves (i.e., imagers). The prism assembly has a second tilt axis, a plurality of color separating surfaces, and a plurality of exit surfaces. The prism receives the polarized light from the polarizing beam splitter, separates the polarized light into a plurality of colors and directs polarized color beams to each light valve. The optical imaging system may include a suitable light source that supplies the incident light.
[0023] In alternative embodiments, the reflective light valve may reflect at least a portion of the first polarized beam back to the original polarizing beam splitter or to a second PBS.
[0024] As stated above, a color prism exit aperture (to the imagers) has an orientation, including a long axis and a short axis. If an optical designer places the imager on the color prism such that the long axis of the imager is parallel to the long axis of the color prism exit aperture, then the designer will achieve the smallest and lightest projector configuration. However, under this condition, because traditionally the tilt axes of the PBS and the color prism are constrained to be parallel to each other, then the designer is constrained to build a tower configuration. Alternatively, a larger color prism can be made to accommodate the imager oriented perpendicularly to the configuration discussed above, but such an orientation has the disadvantages of increasing the size, weight, and cost of the color prism. It also results in a longer back focal length for the projection lens, adding to the complexity, size and expense of this lens. The use of a Cartesian PBS was found to enable the rotation of the color prism such that the tilt axis for the color separating coatings are orthogonal to the tilt axis of the PBS. This allows the user the option to build either a tower of a flat configuration without weight, size, or cost penalty.
[0025] It is highly desirable that the prism be capable of orientation with the tilt axes of its color separation surfaces either parallel to that of the PBS's polarization separation surface or perpendicular to it, as the designer desires. This allows the system designer to have maximum flexibility with regard to industrial design, cooling, imager placement and other practical projection system considerations. The combination of the Cartesian PBS and the color prisms can, at low f/#, enable the color prism and PBS to have crossed tilt axes and obtain good contrast. This allows a flat, low profile orientation with minimized CP size, which is particularly desirable for portable front projection systems. The present work details specific types of color prism to be used, as well as prism orientation to achieve desirable results.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] [0026]FIGS. 1A and 1B are schematic plan views of two embodiments of projection systems in accordance with the present invention.
[0027] [0027]FIGS. 2A and 2B are side perspective views of a first and a second PBS and color prism assembly oriented with parallel and perpendicular tilt axes in accordance with the present invention.
[0028] [0028]FIG. 3 is a graph of APF Cartesian PBS contrast performance vs. wavelength of light.
[0029] [0029]FIG. 4 is a graph of APF Cartesian PBS contrast performance vs. f/#.
[0030] [0030]FIGS. 5 a and 5 b are graphs of the contrast and dark and bright state spectral radiance vs. wavelength for PBS and color prism with parallel tilt axes.
[0031] [0031]FIG. 6 is a pupil image of a dark state Maltese band for a parallel, s-oriented PBS and color prism.
[0032] [0032]FIG. 7 is a pupil image of a dark state Maltese band for APF PBS without color prism.
[0033] [0033]FIG. 8 a is a graph of contrast vs. wavelength for PBS and color prism with crossed tilt axes.
[0034] [0034]FIG. 8 b is a graph of dark and bright state spectral radiance for PBS and color prism with crossed tilt axes.
[0035] [0035]FIG. 9 is a dark state pupil image of Maltese band for perpendicular tilt axes.
DETAILED DESCRIPTION OF THE INVENTION
[0036] [0036]FIG. 1A and 1B are schematic plan views of projection systems in accordance with the present invention. FIG. 1A illustrates an f/2 test system according to the present invention having a PBS and color prism assembly oriented with parallel tilt axes. FIG. 1B illustrates an f/2 test system according to the present invention having a PBS and color prism assembly oriented with perpendicular or orthogonal tilt axes. Referring to FIGS. 1 and 2, the following reference numerals are used in the description.
Part list: 12 Arc lamp 38v “Vertical” dimension of CP 14 Elliptical reflector 38h “Horizontal” dimension of CP 16 Tunnel integrator 40b Blue imager 20 Telecentric illumination 40g Green imager system 40r Red imager 24 Telecentric stop 50 Projection lens 26a, 26b Telecentric lenses 56 PBS tilt axis 28 Pre-polarizer 58 CP tilt axes 30 Polarization beam splitter 60 Illumination optic axis (PBS) 62 Optic axis through CP 32 Cartesian PBS film 36 Philips color prism assembly 38 Color prism exit aperture
[0037] The tilt axes of the PBS and color separation prisms are shown as parallel in this embodiment. The long dimension of the color prism exit aperture is out of the page.
[0038] The present invention analyzes and recognizes a “depolarization cascade” problem that limits the f/# of the illumination optics of traditional optical imaging systems using a PBS based on discrimination between p and s polarization states. Most reflective LCD imagers are polarization rotating; that is, polarized light is either transmitted with its polarization state substantially unmodified for the darkest state, or with a degree of polarization rotation imparted to provide a desired gray scale. A 90° rotation provides the brightest state in these PBS-based systems. Accordingly, a polarized beam of light generally is used as the input beam for reflective LCD imagers. Use of a polarizing beam splitter (PBS) offers attractive design alternatives for both polarizing the input beam and folding the light path.
[0039] The exemplary system illustrated by FIG. 1 differs in some ways from a commercial projector (e.g. there is no provision for converting nominally p-polarized light from the lamp into the desired s-polarization state to improve efficiency), but it does provide a flexible test system which allows easy modification of the f/# of the illuminating beam of light. In the system of FIG. 1, light is emitted from a metal halide or high pressure mercury arc lamp, 12 , and collected by elliptical reflector, 14 . The converging beam of light from the lamp and reflector is inserted into a glass tunnel beam integrator, 16 , which reflects the beam multiple times inside itself by total internal reflection. This results in a more uniform beam intensity being emitted at the down-stream end of the tunnel integrator than was inserted at the upstream end. The tunnel integrator should preferably have the same cross-sectional dimensions as the optically active pixel area of the imagers ( 40 b , 40 g , and 40 r ) to be illuminated.
[0040] After being emitted from the tunnel integrator, the light is collected by the first telecentric lens 26 a of the telecentric illumination system, 20 . This lens is located one focal distance from the emitting end of the tunnel integrator, 16 , and transmits the light through the telecentric stop, 24 , and onto the second telecentric lens, 26 b . Between the telecentric stop, 24 , and the second telecentric lens, 26 b , we have placed a polarizer to polarize the light perpendicularly to the plane of FIG. 1. This is referred to as “vertical” or “nominally s” polarized. The polarizer, 28 , could be placed at a number of places in the system, but the light intensity is lower near the telecentric stop, 24 , than at other convenient places in the system. Placement of the polarizer, 28 , either directly before or after this stop therefore ensures maximum polarizer lifetime.
[0041] The resulting vertically polarized, telecentric beam then passes into the Cartesian PBS, 30 , in which the Cartesian PBS film is oriented to substantially reflect vertically polarized light. It is to be understood that the term “film” is not limiting, and could refer to, for example, the array of elements in a wire grid polarizer, or the 3M APF multilayer optical film polarizer. The light therefore passes into the color prism assembly, 36 , where it is separated into distinct red, green, and blue beams that illuminate the red, green and blue imagers ( 40 r , 40 g , and 40 b ) respectively. For purposes of clarity, the color prism assembly, 36 , is shown in the conventional orientation with the tilt axes of the red and blue reflective coatings parallel to the tilt axis of the Cartesian PBS film, 32 . While this orientation is necessary for the prior art using MacNeille PBSs, it will be shown below that the employment of a Cartesian PBS film, 32 , allows the rotation of the color prism assembly 36 by 90 degrees about the principal axis of the beam, so that the red and blue imagers in the figure would be oriented vertically with respect to one another in the figure, and the nominally s polarized light from the PBS 30 would be p polarized with respect to the color selective surfaces of the Color Prism Assembly 36 .
[0042] This is further illustrated in FIGS. 2 a and 2 b . FIG. 2 a shows an arrangement in which the tilt axes 58 of the Color Prism Assembly 36 are parallel to the tilt axis 56 of the PBS 30 . FIG. 2 b shows the arrangement made possible by a Cartesian PBS 30 in which the tilt axes 58 of the Color Prism Assembly 36 , are perpendicular to the tilt axis 56 of the PBS 30 .
[0043] It should also be noted that the Color Prism Assembly employed in FIG. 1 may be configured so that the green light beam is reflected along with either the red or blue beam, rather than having the green light pass undeflected on to the green imager. In that case, it either the red or blue beam would pass undeflected onto its intended imager.
[0044] Each imager, 40 r , 40 g , and 40 b , is divided into many separate and independent picture elements (pixels), each of which can be individually addressed to rotate the polarization state of the incident light as it is reflected off each pixel. If a pixel element for a particular color channel is intended to be dark, then n 0 polarization rotation occurs at that pixel on the appropriate imager, and the light is reflected back out through the Color Prism Assembly 36 and into the PBS 30 . The light reaching the Cartesian PBS film 32 from this color pixel element is then still vertically polarized, and therefore reflected by the Cartesian PBS Film 32 , back through the telecentric system and into the lamp. Substantially none of this light will propagate into the projection lens assembly 50 and therefore substantially none will be projected onto the screen (not shown). If a pixel element for a particular color channel is intended to be bright, then polarization rotation occurs at that pixel on the appropriate imager, and the light is reflected back out through the color prism assembly, 36 , and into the PBS, 30 . The light reaching the Cartesian PBS film 32 from this color pixel element is then at least partially horizontally polarized, and therefore partially substantially transmitted by the Cartesian PBS Film 32 into the projection lens, and subsequently imaged onto the screen (not shown).
[0045] The degree of horizontal polarization imparted to the light reflected from each color pixel element will depend on the level of brightness desired from the particular color pixel at the time. The closer the rotation of the polarization approaches a pure horizontal polarization state at any given time, the higher the resulting screen brightness for that particular color pixel element at that particular time.
[0046] The present work details specific types of color prism 36 to be used, as well as color prism 36 orientation to achieve desirable results. It is highly desirable that the color prism 36 be capable of orientation with its tilt axes either parallel to that of the PBS 30 or perpendicular to it, as the designer desires. This allows the system designer to have maximum flexibility with regard to industrial design, cooling, imager placement and other practical projection system considerations. For example, the decision as to whether to make a tower configuration (where the shortest dimension of the projector is held horizontal in use) or a more conventional flat configuration (where the shortest dimension in held vertical in use) with the most compact possible color prism assembly would not be an option open to the designer in the absence of the aforementioned flexibility. The alternatives open to a designer using the configuration of FIG. 1 have in the past been: a) design using the most compact possible color prism to accommodate the selected imager, but place the prism in a “tower” configuration, or b) design a larger color prism capable of accommodating the long, horizontal axis of the imager within the shorter dimension of the color prism face. In the second case the projector may be oriented in a flat configuration, but it will be larger and heavier than the alternate tower configuration. The former option may be undesirable for commercial and thermal reasons, while the latter is undesirable due to the premium placed on small size and weight in the marketplace. Because a Cartesian PBS prepares a sufficiently pure polarization state at usefully low f/#, the color prism 36 may be rotated 90° about the optic axis 62 when the Cartesian PBS is employed. This enables the usage of a smaller color prism 36 for the horizontal projector layout.
EXAMPLES
[0047] A 3M APF type Cartesian polarizer film was used as a polarization splitting surface, which allows the PBS film to be placed in a glass cube, similarly to a MacNeille PBS. An advantage of the APF type PBS is that, unlike the MacNeille PBS, it may be used with glass of any index. This allows flexibility for selecting glasses with different properties that may be desirable for different applications. Examples include low blue light absorption where color gamut and balance is important, or low stress optic coefficient for high light intensity applications, or higher index of refraction for smaller angular spread in the glass, allowing smaller components where compact design is important. Secondly, because tilted color separation coatings such as those used in color prisms are sensitive to angle, a fully telecentric beam was used for these experiments. This beam provides a full f/2 cone at all points on the imager, thereby ensuring that all allowable rays of light in an f/2 beam are represented at all image locations in our tests. The system has been designed for maximum flexibility, for example to allow easy changes of illumination f/#.
[0048] The PBS 30 in FIG. 1 is illuminated with light polarized into and out of the page (vertically), so it is nominally an s-polarized beam with respect to the PBS. The vertical direction will be referred to in future as the y direction, and the direction of light propagation will be referred to as the z direction. The color prism 36 depicted is a so-called Philips Prism. However, the detailed results are expected to be independent of the precise color prism configuration.
[0049] The y polarized light incident on the PBS from the lamp 12 is reflected by the PBS into the color prism. The color prism is shown with its reflecting planes for red and blue light rotated about an axis parallel to that about which the PBS is rotated (parallel to the y axis). The configuration shown will be referred to as an “s-oriented” color prism.
[0050] The other case to be considered is that where the color prism is rotated by 90 degrees about the direction of propagation of the central ray of light through the color prism. In this case the inclined color reflecting surfaces are rotated about an axis perpendicular to that of the PBS rotation axis, which will be referred to as a “p-oriented” color prism.
[0051] Wide-angle, high-extinction MacNeille PBS and color prism systems are offered for sale, but are generally designed only to work at f/2.8 and higher. Experimental results using such a MacNeille PBS at f/2 with no color prism and with simulated perfect imagers, yielded only 80:1 contrast. In the present exemplary experimental setup, the simulated perfect imager consisted of a first surface mirror simulating a dark state and a quarter wave film (QWF) laminated to mirror and rotated so that its optic axis was 45 degrees to the incident polarization simulating the bright state. It therefore seems unlikely that contrast at acceptable levels (exceeding 250:1 for perfect imagers, so that system contrast with actual imagers will be adequate) could be possible once the color prism is inserted.
[0052] However, the Cartesian PBS and color prism of the present invention are specifically designed to be used together in a system. The design assumes that the PBS and the color prism are oriented to have their reflective planes rotated about parallel axes. In general, it was found that known previous systems had been designed with the PBS and the color prism having parallel tilt axes for their reflecting surfaces. Such an arrangement appears to have been chosen because the rays that have highest contrast are those propagate within the plane defined by the normal to the reflecting surface and the optical axis (i.e. the reflection plane of the central ray), whether for a PBS or for a color selective surface. Thus, for conventional components with narrow bands of high contrast situated near the reflection plane of the central ray (the so-called Maltese bands) perpendicular tilt axes results in a very small region of high contrast, defined by the overlap of the high contrast band of the PBS and the perpendicular high contrast band of the color prism. The amount of light contained in this very small region of angle space is inadequate to provide acceptable contrast at usefully small f/#'s, and so this configuration is has never been selected by designers using conventional components.
[0053] For the Cartesian PBS, it was found that the band of high contrast for rays reflected from the PBS surface is so broad and the inherent contrast is so good that contrast degradation due to crossing of the tilt axes of the PBS and the color prism is very small. Indeed, in some cases it is not apparent from the data that there is any inherent degradation in contrast, though it was initially expected for such degradation to be easily noticeable. The performance of the components and system will be demonstrated through the examples below.
Example 1
Performance of APF Cartesian PBS with no Color Prism.
[0054] Data was first taken to establish the baseline performance of the APF PBS, the mirror simulation of an imager in its dark state, and the mirror with quarter wave film simulation of an imager in its bright state, along with the overall contrast capability of the system of FIG. 1 (without a color prism). The resulting data is shown in FIGS. 3 and 4 for two different samples of APF Cartesian PBS. The data indicates a very high level of contrast even vis-a-vis the earlier reported performance of plate-type Cartesian PBS systems. FIG. 3 shows the results as a function of wavelength of light at f/2, while FIG. 4 indicates results as a function of f/#. In both cases, the PBS film was contained in a cubic prism made of BK7 glass. In FIG. 4 the data was taken both with and without an optional clean-up polarizer just before the projection lens, to remove stray light due to a slight haze in the PBS prism. The optional polarizer is not present for the data in FIG. 3. These contrast levels indicate that the optical system itself, including the PBS but not the color prism, has a dark state which presents less than 0.1% of the light present in the bright state.
Example 2
Performance of APF Cartesian PBS and Color Prism with Parallel Tilt Axes.
[0055] If the color prism is added to the system, but the imagers continue to be simulated by mirrors and quarter wave films as before, then the effects of the depolarization cascade may be assessed. To evaluate these effects, the color prism was designed to work optimally with light that is perfectly y polarized. The color prism was designed for use at f/#'s down to 2.8, with the PBS and the color prism having parallel tilt axes. Versions of the color prism made of BK7 and of SK5 glass have been used in this work, but the present example focuses on the BK7 glass prism, which has an index of refraction matching that used in the design work. It is important to note , that the color prism was designed to work with perfectly y polarized light, such as that presented by a Cartesian polarizer. It was specifically not designed to compensate the polarization impurities introduced by a MacNeille PBS. (Designing the color prism to ameliorate the angle dependent phase and rotation of the polarization state of the light introduced by the MacNeille polarizer will degrade the performance of a system using a Cartesian PBS. Similarly, a color separation and recombination prism designed to work well with a Cartesian PBS will perform poorly with a MacNeille PBS). Accordingly, the use of a Cartesian PBS simplifies color prism design by removing the necessity for such compensation.
[0056] [0056]FIG. 5 a shows the results of placing the color prism and APF PBS in the system of FIG. 1 with parallel tilt axes. In taking data for this figure a “notch filter” has been used to block light from the low contrast yellow and cyan regions. (These spectral regions have low contrast due to the effects of band edges in the color separating coatings on the phase of light near the band edges). FIG. 5 b shows the dark and light state irradiance in the same arbitrary units. The photopic contrast ratio is 389:1.
[0057] [0057]FIG. 6 shows the Maltese band of the dark state for the system configuration of FIG. 5, and FIG. 7 shows (for comparison) the same Maltese band for the APF with no color prism. For parallel tilt axes, the Maltese band of the color prism overlays and is parallel to that of the PBS. This reduces the width of the resulting Maltese band, resulting in a decrease in the contrast ratio between the configuration used in FIGS. 3 and 4 without a color prism, and that used for FIG. 5 with a color prism.
[0058] The degradation of contrast outside the relatively narrow region around the reflection plane of the central ray may be attributed to the color prism. This is evident from FIG. 7, which shows the equivalent pupil image when the color prism is removed. The digital camera used for these images automatically re-scales the brightness of the image, so direct comparisons between the two figures is not possible. However, the contrast ratio for the configuration of FIG. 7 is about six times that for FIG. 6, meaning that this dark state pupil image is six times darker than FIG. 6.
Example 3
Performance of APF Cartesian PBS and Color Prism with Perpendicular Tilt Axes.
[0059] Because the Maltese band for the PBS itself is so deep and broad, we expect that there may be a minimal degradation in contrast resulting from the crossing of the Maltese band due to the color prism with that due to the PBS. In this case, rather than figuratively overlaying the narrow horizontal Maltese band of the color prism over the broad horizontal Maltese band of the PBS, a vertical Maltese band is overlayed due to the color prism cross-wise over the broad horizontal Maltese band of the PBS. Due to the extremely broad nature of the Maltese band of the APF PBS (the pupil image contains rays with polar angles out to about 14°) the degradation in contrast resulting from this crossing of bands is small. This is quite different from the case for conventional MacNeille PBS components.
[0060] [0060]FIG. 8 demonstrates the performance obtained when the color prism is rotated so that s-polarized light from the PBS became p-polarized relative to the inclined surfaces of the color prism. It is clear that the contrast is somewhat lower than in FIG. 5, but the reduction is quite small, only about 15% (301:1 vs. 360:1). In addition, because a high pressure Hg lamp was used, and because these lamps present a non-uniform, peaked spectral intensity function (as can be seen in FIGS. 5 b and 8 b ) the photopic contrast is quite sensitive to the precise wavelengths at which the color prism coatings provide the best contrast.
[0061] The peaked nature of the spectral intensity function of the lamp makes final system performance very sensitive to small variations in the spectral contrast performance of the color prism. It is therefore essential to refine the color prism design to ensure that peak spectral contrast wavelength remains at the spectral peaks of lamp intensity after rotating the prism tilt axes so that they are not parallel to that of the PBS. FIG. 9 depicts the Maltese band for the perpendicular tilt axes configuration. In keeping with the minimal contrast ratio differences seen between FIGS. 5 and 8, this image looks much like that of FIG. 6, rotated by 90°. | An optical imaging system including an illumination system, a Cartesian PBS, and a prism assembly. The illumination system provides a beam of light, the illumination system having an f/# less than or equal to 2.5. The Cartesian polarizing beam-splitter has a first tilt axis, oriented to receive the beam of light. A first polarized beam of light having one polarization direction is folded by the Cartesian polarizing beam splitter and a second polarized beam of light having a second polarization direction is transmitted by the Cartesian polarizing beam splitter. The Cartesian polarizing beam splitter nominally polarizes the beam of light with respect to the Cartesian beam-splitter to yield the first polarized beam in the first polarization direction. The color separation and recombination prism is optically aligned to receive the first polarized beam. The prism has a second tilt axis, a plurality of color separating surfaces, and a plurality of exit surfaces. The second tilt axis maybe oriented perpendicularly to the first tilt axis of the Cartesian polarizing beam-splitter so that the polarized beam is nominally polarization rotated into the second polarization direction with respect to the color separating surfaces and a respective beam of colored light exits through each of the exit surfaces. Each imager is placed at one of the exit surface of the color separating and recombining prism to receive one of the respective beams of colored light, wherein each imager can separately modulate the polarization state of the beam of colored light. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part application of our earlier co-pending application Ser. No. 466,778, filed May 3, 1974, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a method for preserving high moisture content agricultural grains which become subject to bacterial degradation due to the high moisture content present. More particularly, the present invention is directed to a method for preserving such high moisture content agricultural grains by treating said grains with a specific acid/surfactant admixture.
2. Description of the Prior Art
U.S. Pat. No. 3,682,653 discloses the use of a surfactant and propionic acid, in combination, as a grain conditioner lubricant for softening a mass of whole kernel grains. Essentially, the patentee employs a mixture of liquid lecithin, propionic acid, and water. The propionic acid serves to reduce the pH of the lecithin such that the lecithin becomes water dispersible.
The invention of this patent is quite different from that disclosed and claimed herein for a number of reasons. Firstly, the patentee is not at all concerned with the preservation of high moisture content grains. Secondly, the patentee requires the presence of a natural amphoteric surfactant (lecithin), whereas, as will be seen from the discussion which follows, a synthetic organic cationic or anionic surfactant is required for the instant invention to enhance the spreading factor of the acid contained in the present composition required to preserve the high moisture content grains. Non-ionic of amphoteric surfactants will not suffice to this end. Thirdly, one observes upon a reading of this patent, that the patentee requires propionic acid for the purpose of dispersing the lecithin, whereas in the instant invention, the surfactant is employed for the sole purpose of dispersing the acid of the present composition in the high moisture content grain for preservation purposes.
Finally, according to the patentee, one-fourth lb. of acid per ton of grain would be required, whereas with the present invention, appreciably more acid per ton is required, and as such, the patentee's acid content would be so minimal as to prevent preservation of the high moisture content grain.
U.S. Pat. No. 2,890,120 discloses a method for preserving edible plant materials, i.e., fruits and vegetables which become deteriorated via enzyme deterioration. Specifically, the method includes applying to said plant materials, a composition containing at least an acid, a volatile oxygenated organic solvent and a surfactant. The invention of this patentee is distinguished from the invention disclosed and claimed herein on at least two bases. Firstly, the plant materials of the patentee are deteriorated via enzymes whereas the grain material disclosed in the instant invention is deteriorated through bacteria as a result of the high moisture content present. Secondly, the patentee requires the presence of a volatile oxygenated organic solvent for two reasons: (1) to facilitate the penetration of the patentee's acid through the cell walls and membranes of his plant materials, and (2) for acting synergistically with the other components of the patentee's solution to promote enzyme inactivation. In the instant invention, no volatile oxygenated organic solvent is at all required. In fact, to employ such would be detrimental to the purposes intended to be achieved by the present inventors.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to provide a method for preserving high moisture content agricultural grains.
Accordingly, to this end, it is intended for the purpose of this invention, to employ a high moisture content agricultural grain preserving composition, which consists essentially of: (1) a food-grade organic acid, or phosphoric acid, and (2) a synthetic organic cationic or anionic surfactant for enhancing the penetration of the acid employed in this composition into the high moisture content grain, thus effecting preservation of the same. Nonionic and amphoteric surfactants will not suffice.
By way of definition, the term "food-grade organic acid" refers to conventional organic acids known and approved for use with food products.
The term "high moisture" as it pertains to agricultural grains means any agricultural grain whose moisture content is 18% or more.
DETAILED DESCRIPTION OF THE INVENTION
With respect to the food-grade organic acids suitable for the purpose of this invention, those acids which are preferred, are those of formic acid, acetic acid, propionic acid, and lactic acid. Of these, propionic acid is the acid of choice because it not only serves the function required of an acid for the purpose of this invention, but, in addition, this particular acid is an effective fungicide and as such, enhances the preservation power of the composition employed. However, any other food-grade organic acid approved for use by the Food and Drug Administration's "GRAS" list is acceptable also.
With respect to the concentration parameters for the acids and surfactants employed in the present composition, naturally, the concentration of same will vary over wide limits, depending upon the moisture content of grain treated. However, generally, the following guidelines are suggested.
For one ton of grain containing 25% moisture content, the following active ingredient concentrations are suitable for applicants' purposes:
1. Acid--10 lbs.
2. Surfactant--2 lbs.
Similarly, for 1 ton of grain having a moisture content of 15%, the following active ingredient concentrations are suitable:
1. Acid--21/2 lbs.
2. Surfactant--7/10 lb.
Referring to the above examples, with respect to the grain having a moisture content of 25%, 12% of that moisture is inactive. Consequently, the amount of active water in the 25% moisture grain is actually 13% (25-12%).
Similarly, with respect to the grain having a 15% moisture content, the amount of active moisture contained in said grain would be 3% (15-12%).
Accordingly, 15% moisture grain required 3/13 times the formula or roughly one-fourth of the formula used for application to a 25% moisture grain. This is based on perfect mixing conditions. For practical purposes it may be necessary to use an inert diluent. Based on the foregoing guidelines, it is believed that the skilled artisan can easily calculate the amount of acid and surfactant required for applicants' purposes simply by determining the amount of moisture content contained in a particular grain and calculating the amount of each active ingredient required on a proportional basis in light of the above guidelines.
With respect to the surfactants suitable for applicants' purposes, applicants do not limit themselves to any particular cationic or anionic surfactant. That is, virtually any of these will suffice. However, without limitation, the following commercially available surfactants have been found to be quite suitable. Any sodium alkylsulfonethanolamine; any ammonium or sodium alkylarylpolyethersulfonate (Triton); any long alkyl chain sulfonate; any alkyl aryl sulfonate; any sulfonated fatty acid; or any sodium sulfosuccinate. Specific illustrative examples of the following aforementioned types of surfactants are: sodium dodecylsulfonethanolamine, ammonium dodecylbenzenepolyethersulfonate, sodium dodecylbenzenepolyethersulfonate, dodecylsulfonate, sodium dodecylbenzenesulfonate, sulfonated myristic acid, sulfonated palmitic acid, sulfonated stearic acid and di(2-ethylhexyl)sodium sulfosuccinate. These and other cationic and anionic surfactants useful in the instant invention are found and described in the text entitled "ENCYCLOPEDIA OF SURFACE ACTIVE AGENTS," by Sisley and Wood, published by Chemical Publishing Company, New York, N.Y. (1964).
Naturally, for the purpose of this invention, more than one food-grade acid can be employed; that is, mixtures of conventionally acceptable food-grade acids are equally as suitable for the purposes of this invention.
With the foregoing in mind, the following brief explanation will provide the skilled artisan with a basis to fully understand the uniqueness and novelty of the present invention.
Firstly, the basis of this invention is the realization that food-grade acids can be used to preserve high moisture content grain, such as corn grain or any other agricultural grain. However, a problem arises when using such an acid and mainly, the acid alone cannot normally penetrate or permeate through the high moisture content grain sufficiently to impart this preservation effect.
Consequently, the uniqueness of the instant invention is the realization that when a conventional food-grade acid and a synthetic organic cationic or anionic surfactant capable of enhancing penetration of that acid through high moisture content grains are administered concomitantly the surfactant enables the food-grade acid to fully penetrate throughout the high moisture content grains so as to permit an overall substantial preservative effect to be achieved.
In application, one simply determines the amount of high moisture content grains to be treated as well as the amount of moisture contained in that grain. The amount of moisture contained in a particular grain can be easily determined by means well known to the skilled artisan concerned with the subject matter of this invention. Subsequently, based upon these estimations, the basic formulation of the present invention is prepared by simply mixing together the essential ingredients. Then, the prepared formulation is applied to the high moisture content grain by any suitable means, for example, spraying the same onto the grain mass, until the high moisture content grain is saturated with the formulation.
A better understanding of the present invention will be gained from the following examples, which are simply illustrative and non-limitative thereof.
EXAMPLE I
This example, set out in two parts (part A and part B) illustrates the "spreading factor" discussed in connection with the formulation of this invention.
Part A. (Rate of penetration of the acid through the grain mass; the SPREADING FACTOR)
______________________________________Formulation Inches per Hour______________________________________50% -Propionic acid 5.0 -50% - Mixture of Propionic acid (60%) 5.1and Acetic acid (40%) 5.150% -Acetic acid 5.250% -Propionic acid and 1/10% sodiumalkylsulfonethanolamine* 7.5______________________________________
Each of the above formulations were diluted with distilled water to the required percent. 35mm. Pyrex tubes (specially prepared) were employed. High moisture corn (25%) was packed in the tubes at 5 lbs. per square inch at each inch level. All experiments were conducted at 70° F. These values hold only for the particular batch of corn used and are not absolute, and vary with the degree of attrition if ground.
Part B. (Rate of penetration of the acid through the grain kernal; the "ABSORPTION FACTOR")
Percent Absorption in HoursFormulation 1/2 1 2 4 12 24__________________________________________________________________________50% - Propionic acid 20 24 28 28 30 3750% - Propionic acid/Acetic acid- 60/40 mixture 19 23 26 29 32 3550% - Acetic acid 25 31 34 36 40 4550% - Propionic acid and 1/10% sodium alkylsulfonethanolamine* 30 38 35 56 64 75__________________________________________________________________________ *sodium dodecylsulfonethanolamine?
In the above comparative studies, 100 gram portions of the 25% moisture corn were employed. The various test liquids were mixed at the rate of 1% with the grain mass. The preparation was allowed to stand for the varying time periods noted at 50° F. The test liquids were then eluted from the grain with three successive washes of distilled water. Aliquots were titrated for acid not absorbed and calculations were noted for the percent of acid absorbed. These values are not absolute and hold only for the particular batch of corn used, and vary with the degree of attrition if ground.
EXAMPLE II
Growth of Mold in OF MOLD IN 30% High Moisture Corn at 70° F
DaysFormulation 4 14 28 80______________________________________1/2% - Propionic acid 0 1 2 31/4% - Propionic Acid 1 2 4 41/2% - Propionic acid and 1/10% sodium alkylsulfonethanolamine* 0 0 1 21/4% - Propionic acid and 1/10% sodium alkylsulfonethanolamine* 0 0 2 4______________________________________
In the above comparisons, 200 gram samples in wide mouth jars with loose lids were allowed to stand over water in a loose-lidded container at 70° F. The growth of mold in the high moisture corn employed was then determined. The degree of mold growth ranged from 0 or no growth to 4 or maximum growth.
EXAMPLE III
With respect to the surfactants illustrated previously and used for present purposes, the following data, set out in Table I below is pertinent from the standpoint of demonstrating the ability of the same to enhance acid penetration.
TABLE I__________________________________________________________________________ PercentSurfactant Absorption__________________________________________________________________________Sodium alkylsulfonethanolamine*+propionic acid (50%) 75Ammonium alkylarylpolyethersulfonate.sup.1 +propionic acid 790%)Sodium alkylarylpolyethersulfonate.sup.2 +propionic acid 770%)Sulfonated fatty acid.sup.3 +propionic acid (50%) 68Propionic acid by itself (50%) 33Conditions same as in Example I, Part B.__________________________________________________________________________ *Sodium dodecylsulfonethanolamine .sup.1 Ammonium dodecylbenzenepolyethersulfonate .sup.2 Sodium dodecylbenzenepolyethersulfonate .sup.3 Sulfonated palmitic acid
These values are not absolute and serve only as examples as they vary with the particular batch of corn used, and degree of attrition if ground. These are weighted values based on the surfactant employed and propionic acid.
Although the present invention has been adequately described in the foregoing specification and examples included therein, it is obviously apparent that various changes and/or modifications can be made thereto without departing from the spirit and scope thereof. | There is provided, a method for preserving high moisture content agricultural grains, which comprises treating such grains with a composition consisting essentially of (1) an organic foodgrade acid or phosphoric acid, and (2) a synthetic organic cationic or anionic surfactant for enhancing the penetration of said acid into and through said grains. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to electric lighting fixtures mountable within a ceiling and a louver system therefor.
2. Brief Description of the Prior Art
Many commercial and residential buildings have lighting fixtures which are mounted over the area to be lit, such as an office, work station, workshop, storage area or the like. Typically, but not necessarily, such lighting fixtures incorporate one or more fluorescent, incandescent, or other bulbs or devices for generating or emitting rays of light. Such bulbs are mountable within a housing therefor which is placed into, through, or in proximity with a ceiling, such that the intent is to provide maximum light deflection downwardly, vertically and horizontally away from the light fixture. Louver systems for such devices are typically made of an extruded plastic or, alternatively, a configured metallic sheet of metal, such as aluminum. Such metal may be expected to have applied thereon prior to the louver manufacturing procedures, an anodized protectant which also acts as a polish for the surface of the metal to further enhance reflectivity. Unlike extruded plastic louver systems, louver systems made of such metallic material can be expected to form cracks or other surface defects during manufacture. These defects will, in turn, reduce maximum reflectivity of the louver. A typical prior art metallic louvers which are made from a single piece of metal which has a first end horizontally extending to a point which begins to define a side portion which tapers to a lower or distal end which is "u"-shaped with a companion tapered surface extending back to the top and terminates in another horizontal member directed toward the first horizontal member, but not connected thereto. An opening is provided between such two horizontal members which permits light rays from the fluorescent or other bulb or source to penetrate into an open interior and to be captured therein. Such prior art louver is somewhat like a "bobbie pin" which a lady might use in forming a hair style, or the like.
Such prior art metallic louvers have now been found to be deficient for at least four reasons. First, the opening through the upper or dorsal end of the louver allows light rays to enter into and be captured within the louver. To the extent that the light rays are received therein, such light rays are not available for maximum reflection from and away from the lighting fixture. Secondly, because the dorsal end of such louvers is in horizontal alignment with most of the interior of the lighting fixture housing, light deflection off of the surface of such horizontally disposed end is directed back toward the lighting fixture itself. Thirdly, such prior art metallic louvers result in a "u"-shaped distal end because the taper of the sides is not overlaid. Not only is this aesthetically displeasing, but the prior art "u"-shaped distal end enhances the area of the opening interior of the louver, and enhances obstruction of useable light by reducing maximum curvature of the side members by the amount of open area between the tapered side members in an amount equal to the open interior area within the "u"-shaped end. Fourthly, the prior art metallic louver "u"-shaped end results in surface imperfections, resulting from bending or flexing of the metal, such that additional machining and manufacturing steps are required to abate such surface imperfections.
The present invention is directed to reducing such deficiencies in prior art anodized metallic louvers.
SUMMARY OF THE INVENTION
The present invention is directed to providing a lighting fixture which may be mounted relative to a ceiling. The fixture may be mounted within the ceiling, or slightly above or below it. For example, the lighting fixture may be placed somewhat below the ceiling and be mounted relative to the ceiling by the use of chains or lines extending lowerly of the ceiling to the lighting fixture housing. Alternatively, the lighting fixture may be mounted through the ceiling in known manner. The lighting fixture comprises a lighting fixture housing having means within the housing for receipt of an electrical light generating element. The light generating element typically will be one or a plurality of fluorescent light members, but may also be one or more incandescent light bulbs, and other known or equivalent means of generating or providing electrical light.
Within the light fixture may be found a light directing anodized metallic sheet louver system for placement through the light fixture to provide deflection of the light rays from the bulb or other means. Although the preferred metallic louver may be made of an aluminum-containing material, other like or similar metallic materials also may be utilized. The metallic louver will be provided in a form which anodizes the surface of the sheet to provide a fine polish-like film onto the metal for additional light reflectivity enhancement.
A series of louver fins are provided for use with the lighting fixture. The fins and louver system may be manufactured as separate elements to be finally installed by interengagement and known fashion at the site of or prior to installation of the lighting fixture. Alternatively, the fins may be interengaged to form the louver system and shipped interiorally of the lighting fixture housing such that the louver system is a component part of the lighting fixture and the fluorescent or other light generating bulb. Typically, the fluorescent light or other bulb will be inserted into the lighting fixture housing after installation thereof relative to the ceiling and the louver system installed relative to the lighting fixture thereafter.
The fins forming the louver system include a horizontally enlarged dorsal end member which has face portions directable toward the light fixture housing. The face portions extend to vertically and lowerly projecting tapered side members, with each of the side members having a maximum width. Each of the side members are joined at a point of juncture and terminate at a distal end point having a width no greater than the maximum width of both of the tapered side members.
In a preferred form, the fins have the horizontally enlarged dorsal end face extending completely across the dorsal end of the fin to thereby fully enclose the interior of the fin, thus completely eliminating the entry of light rays into the interior of the fin from the top of the fin. The horizontally enlarged dorsal end face may be convex or may be angled outwardly of and away from the interior of the fin.
The fin for the louver system may be provided with a distal end point which is essentially ninety degrees relative to the tapered side members at the point of juncture to thereby provide maximum reflectivity and aesthetic appeal of the louver fin at the point of juncture of the side members.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a vertical cross-sectional view of prior art fins forming a louver system installed relative to a light fixture housing including a fluorescent bulb.
FIG. 1B is a view similar to that shown in FIG. 1A, but in horizontal plane.
FIG. 2A is a vertical view similar to that shown in FIG. 1A, illustrating the fin and louver system of the present invention.
FIG. 2B is a view similar to that of FIG. 2A, but shown in horizontal plane.
FIG. 3 is a plainer view, looking upwardly, of the louver system of the present invention installed relative to a ceiling.
FIG. 4 is an enlarged cross-sectional view of a prior art louver fin.
FIG. 5 is a view similar to that of FIG. 4 illustrating the fin of the present invention.
FIG. 6 is a view similar to that of FIG. 5, but showing a convex dorsal end of the fin of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now referring to FIGS. 2A and 2B, a lighting fixture 200 includes a lighter fixture housing 201 having interiorally affixed thereto a series of lighting receptacles 202 for receipt of a light generating element, 203, preferably a fluorescent light bulb. The light bulbs incorporated for use into the present invention are not, per se, a part of the invention itself.
A louver system 204 is formed by interengaged louver fins 205. The interengagement of one fin with another is accomplished in conventional fashion such as by tabs, vertical grooves and the like. The particular interengagement means will be readily appreciated by those skilled in the art in view of the disclosure and drawings herein. The louver system 204 may be installed relative to the lighting fixture 200 such as in or relative to a ceiling (FIG. 3).
Reference now will be made to FIGS. 4 and 5. First, with respect to FIG. 4, a prior art louver 100 is shown having a u-shaped distal end 101 and an open interior 102. An opening 102A defined by the disjuncture of horizontal top element members 103A and 103B permits light rays to be captured in the open interior 102 resulting in such light rays not being available for maximum reflection from the lighting fixture.
Turning now to FIG. 5, the louver fins 205 are provided with a closed interior area 206 resulting from the dorsal end 207 of the fin 205 being completely closed to eliminate the opening, as in prior art fin FIG. 4, at 102A. The louver fin 205 provides angled face members 207A and 207B to be joined or, most preferably, to result from the manufacturing of the louver fin 205 from one piece of anodized metallic sheet where the ends thereof are at the distal end point 210 and not at the dorsal end 207. The angle 207C and the complimentary angle 207D need not be the same, but each should not be less than about 65°, nor more than about 145°.
Each of the face members 207A and 207B extend downwardly from the dorsal end 207 to form complimentary inwardly tapered side members 208A and 208B each of the members 208A, 208B having a maximum width 208C and 208D. The tapered side members 208A and 208B continue to a point of juncture 209 where the interior surfaces of the tapered members 208A and 208B touch. Preferably, the point of juncture 209 will result not only from the interior sides of the tapered side members 208A and 208B touching one another, but such "touching" is provided by approximately exact overlay of the members 208A and 208B relative to one another such that the maximum width 208C plus the maximum width 208D will equal the width of the point of juncture 209.
The point of juncture 209 may be, or may not be, the distal end point 210, as the side members 208A and 208B defined as the point of juncture 209 may extend distally, somewhat, to the distal end point 210. Alternatively, if no extension is desired, the point of juncture 209 may also define the distal end point 210. The distal end point 210 is essentially 90° relative to the tapered side members 208A and 208B at the point of juncture 209. The distal end point 210 formation will result in square corners with clean surfaces requiring little, if any, manufacturing steps thereafter directed at correction of surface imperfections, resulting in a reduction of time and cost in manufacturing over that required for prior art fins, such as that shown in FIG. 4.
Photometric tests are performed to allow a lighting practitioner to predict the amount of illumination that will be present in a given space or area. The Illumination Engineering Society of North America has published the practices by which these tests are to be performed.
The two basic type of photometry are relative and absolute. In absolute photometry, the actual lamp lumens produced by the equipment at the time of test are used for the calibration of the photometer. These lumen values can vary from lamp to lamp and from test to test with the same lamps. In relative photometry, the rated lumens, those initial lamp lumen values published by the lamp manufacturer, are used for the calibration.
Relative photometry allows a direct comparison between the same type fixtures produced by different manufacturers. There are several basics in any photometric procedure. New lamps must be seasoned for at least 125 hours before they are used. In the case of fluorescent lamps, they should be uniform in output about their diameter by +/-2%. The voltage supplied to the fixture during test should be constant and regulated to +/-2%. The temperature around the fixture during the test and lamps during calibration should be 77 degrees F.+/-2.5 degrees. At the same time, the air velocity shall be less than 30 fpm (feet per minute). The same ballast and lamps must be used for calibration as well as test. The sensing element (light cell) must be at least 5 times the maximum dimension of the fixture away from the fixture. In the case of a 2×4 fixture the cell distance is at least 22.4 feet. The light output of the fixture or lamps must be stable and constant for a least 15 minutes before proceeding with a test or calibration. Finally, the fixture should be in its normal burning position during the test. If the test conditions are followed closely, the photometric test will fall within the acceptable 2.5% repeatability and accuracy.
In the tests, a percentage of the total light from the lamps that is released into the room space as useable light is the efficiency of the lamp and louver system. The remainder of the light is lost and/or absorbed by the fixture, including the louver system.
In accordance with the test description set forth above, the fixture of the present invention was compared with that of a typical prior art louver system to determine light efficiency. Each louver system and fixture incorporated three 32 watt T8 fluorescent lamps in a 2×4 recessed luminaire with white body with a 3" deep 18-cell semi-spec louver. After testing, a lighting efficiency of the device of the prior art was found to be 73.8%. The test was repeated, substituting the louver system of the prior art with that of the present invention. All testing procedures and standards were repeated. In the test incorporating the louver system of the present invention, the lighting efficiency was found to be 76.7%, which is equal to a 4% improvement over that incorporating the prior art louver device, as typified in the prior art Figs. herein.
As shown in FIG. 6, the horizontally enlarged dorsal end face 207 may be configured as conveyed, such as convex surface 207'.
Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention. | An electric lighting fixture for mounting relative to a ceiling is disclosed. An enhanced light deflecting louver system is also disclosed in which the louvers provide enhanced light deflection. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to dual mode venturis for a catalytic burner, particularly catalytic campstoves, wherein one mode is used for initial ignition of the fuel and stable pre-heating of the catalyst-coated plate and a second mode is used to prevent flashback during steady-state regime catalytic combustion phase.
Before operating in the steady-state regime catalytic combustion phase, the catalyst-coated plate of a catalytic burner, such as is disclosed in U.S. Pat. No. 4,588,373, issued May 13, 1986 to Tonon et al., must be pre-heated to a temperature, on the order of 300°-700° Kelvin. This temperature, referred to as a light-off temperature, is a function of the specific fuel mixture, and is accomplished by the heating of the underside of the catalyst-coated plate by means of a conventional flame. This conventional flame is fueled by a fuel and air mixture from a venturi pipe leading to apertures in the burner head. During this pre-heating or warm-up phase, it is desirable that the fuel or gas velocity from the apertures of the burner head is less than the flame speed in the fuel mixture. This allows the flame to establish itself at the burner head to heat the catalytic-coated plate directly. During this phase, if the fuel or gas velocity were greater than the flame speed, a flame would not be able to attach to the burner because it would "blow off", thereby making it difficult or impossible to maintain a stable flame during pre-heating except possibly in regions of reduced gas velocity or recirculating, turbulent flow.
However, after the warm-up phase, during the catalytic combustion phase, it is desirable that the fuel or gas velocity be higher than the flame velocity so as to establish and maintain the combustion at the catalytic plate and away from the burner head. If the fuel or gas velocity is lower than the flame velocity, then the temperature of the fuel mixture flowing from the burner head to the plate entrance may be high enough that a flame may travel back to and stabilize at the burner head thereby preventing stable catalytic combustion operation.
Prior efforts made to merely vary the size of the burner exit holes between the warm-up and the catalytic combustion phases had an unwanted side effect of changing the quantity of air entrained into the venturi, thereby causing the air-fuel mixture to change.
Additionally, in the prior art, catalytic burners were optimized for radiative heat transfer which is particularly well-adapted for cooking. However, such applications, as drying off fibers or domestic heating with conventional heat exchangers demand convective heat transfer, or the production of a very hot gas rather than radiative heat transfer. Heretofore, it has not been understood how to systematically vary the ratio of radiative to conductive heat transfer in a catalytic burner.
In view of the above, it is the principal object of this invention to provide an improved catalytic burner apparatus in which the fuel mixture exits the burner head during the pre-heating phase at a velocity less than the flame velocity so that the flame will not "blow off" the burner and in which the fuel mixture exits the burner head during the steady-state catalytic combustion phase at a velocity greater than the flame speed so that the locus of the combustion is on the catalytic plate and does not "flash back" to the burner.
It is therefore a further object of this invention to provide for varying the size of the air entrainment openings at the venturi's entrance simultaneously with varying the fuel velocity from the burner head so as to maintain an optimal air-fuel mixture.
It is therefore a further object of this invention to provide a method for varying the proportion between radiated and convected energy within a catalytic burner.
SUMMARY OF THE INVENTION
The above and other beneficial objects are achieved in accordance with the present invention by providing a catalytic burner with two concentric cylindrical venturi tubes. The outer venturi tube has apertures or exit holes of a first diameter of even integer multiples of 30 degrees about a circular section of its periphery and apertures or exit holes of a second diameter, smaller than the first diameter, at odd integer multiples of 30 degrees about a circular section of its periphery. The inner venturi tube has apertures or exit holes of the first diameter at odd integer multiples of 30 degrees about a circular section of its periphery and apertures or exit holes of the second diameter at even integer multiples of 30 degrees about a circular section of its periphery.
Additionally, the outer venturi has a circular air entrainment opening at the venturi entrance. The inner venturi has a pear-shaped air entrainment opening which is formed by slightly overlapping two adjacent circles, one of a diameter of the air entrainment opening of the outer venturi and one at a reduced diameter.
This allows rotation of the outer venturi so that the apertures or exit holes of the larger first diameter of the inner and outer venturis are aligned and the circular air entrainment openings of the outer venturi are aligned with the smaller portion of the pear-shaped air entrainment openings of the inner venturi. This results in a lower gas speed from the burner allowing the flame to attach itself to the burner head during the pre-heating stage without "blow off". Additionally a desirable rich fuel/air mixture is maintained.
After the pre-heating stage is over, the outer venturi is rotated, manually or automatically, momentarily cutting off gas flow as all exit holes are blocked thereby extinguishing the conventional pre-heating flame. Further rotation aligns the apertures of a first diameter of the outer venturi with the aperture of a second diameter of the inner venturi and vice versa thereby resulting in effective apertures of the smaller second diameter and a resultant gas speed which is increased so as to establish catalytic combustion at the catalytic plate with a substantially reduced tendency of "flashing back" to the burner. Additionally, the alignment of the air entrainment openings of the inner and outer venturis is changed so as to increase the effective size of the air entrainment openings thereby resulting in a lean air/fuel mixture more desirable for the catalytic combustion regime.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a simplified side elevational sectional view of a catalytic stove in accordance with the present invention.
FIG. 2 is a plan view, partly in elevation, of the outer venturi of the present invention.
FIG. 3 is a plan view, partly in elevation, of the inner venturi of the present invention.
FIG. 4 is a cross-sectional view along 4--4 in FIG. 1.
FIG. 5 is a cross-sectional view along 5--5 in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is now made to the drawings wherein like numerals indicate like elements throughout the several views. FIG. 1 discloses the catalytic burner apparatus 10. Apparatus 10 includes a base 12 which proves stability for both the apparatus and the cooking vessel (not shown) which is placed upon the apparatus. Additionally, base 12 acts as a heat dissipator for the rest of the apparatus. Valve body 14 is mounted on base 12 by mounting post 16 thereby proViding a heat transfer path to the base 12. Valve body 14 includes a valve 18 which is mounted for rotation therein. The rotation of valve 18 is responsive to knob 20 thereby controlling or metering the flow of gas from a gas source (not shown), through needle 22 and into venturi assembly 24. Needle 22 mounts the gas source (not shown) to apparatus 10. Needle 22 further serves as a heat exchanger for fuel vaporization (as the fuel and heat are in counterflow, this creates a heat exchanger with a high thermal gradient between the hot `outlet` and the cold `inlet` end) and as a heat insulator between the valve body 14.
Valve 18 has an orifice (not shown) for the passage of fuel from the valve 18 to the venturi assembly 24. This orifice is typically 0.008 inches in diameter, includes a sintered metal filter (not shown), and acts as a heat exchanger for further fuel vaporization.
The venturi/diffuser assembly 24 is mounted on valve body 14 with its longitudinal axis vertical so as to receive gas from the orifice of valve 18. Venturi/diffuser assembly 24 includes an outer sleeve 26 (see FIG. 2) concentric with an inner sleeve 28 (see FIG. 3). Inner sleeve 28 is fixed onto valve body 14 and outer sleeve 26 rotates about inner sleeve 28 responsive to the user manually pushing on lever 30 attached thereto.
The outer sleeve 26 has larger diameter exit apertures 32 (typically 1/8 inch) at even integer multiple of 30 degrees (30 degrees may be replaced by other values of 360 degrees divided by an even integer) about a circular portion near the upper end of outer sleeve 26. Outer sleeve 26 further has smaller diameter exit apertures 34 (typically 1/16 inch) at odd integer multiples of 30 degrees (or some other suitable angle) about the same circular portion near the upper end of outer sleeve 26.
The outer sleeve 26 includes circular air entrainment openings 36 about a circular portion near the lower end of outer sleeve 26 and a lever 30 integrally attached thereto.
The inner sleeve 28 has larger diameter exit apertures 38 at odd integer multiples of 30 degrees (or some other appropriate angle) about a circular portion near the upper end of inner sleeve 28. Inner sleeve 28 further has smaller diameter exit apertures 40 at even integer multiples of 30 degrees (or some other appropriate angle) about the same circular portion near the upper end of inner sleeve 28.
The inner sleeve 28 includes pear-shaped air entrainment openings 41 about a circular portion near the lower end of inner sleeve 26.
As will be described in more detail, this venturi/diffuser assembly 24 allows a user to select (1) rich fuel/air mix (reduced air entrainment opening size) with a low fuel velocity (increased exit hole diameter) for easy ignition without "blow off" from the exit holes thereby being suitable for ignition or preheating or (2) a lean fuel/air mix (enlarged air entrainment opening size) with a high fuel velocity (decreased exit hole diameter) for steady-state regime catalytic combustion without "flash back".
Venturi/diffuser assembly 24 further acts as a structural element to engage the cup 42 and as a heat transfer path from the cup 42 to the valve body 14. The top of venturi/diffuser assembly acts as a heat collector.
Flange 44 adds detachable structural support and a heat transfer path between venturi/diffuser assembly 24 to cup 42.
Cup 42 is a bowl-shaped element which is supported by flange 44 and supports catalyst assembly 46 via gasket 54, insulator 48, igniter 50, and heat collector 52. Further, cup 42 provides a heat transfer path from the heat collector 52 to the venturi/diffuser assembly 24.
A gasket 54 is mounted between the cup 42 and catalyst assembly 46 so as to prevent leakage of the fuel mixture around the catalyst assembly 46 and to cushion catalyst assembly 46 against damage.
The catalyst assembly 46 includes a ceramic substrate with a catalytic coating. This coating may be selected from the group consisting of platinum, palladium, rhodium and iridium as described in the aforementioned U.S. Pat. No. 4,588,373. This catalytic coating effects catalytic combustion when the air/fuel mixture contacts the pre-heated catalytic assembly 46.
Heat collector 56 mounts on cup 42 over catalyst assembly 46 and gasket 54. The heat collector 56 transfers heat from the catalytic assembly 46 to the cup 42 and to the cooking vessel (not shown). The heat transfer connection between the heat collector 56 and cup 24 should be efficient so as to effect the preliminary heat transfer for subsequent heat transfer through the aforementioned structural parts of apparatus 10.
The igniter 50 creates a high voltage for spark ignition. While the preferred embodiment discloses the igniter 50 attached to the cup 42, other acceptable mounting locations are the valve body 14, the venturi/diffuser assembly 24 or the base 12. Electrode 58 is an electrical terminal for spark ignition of the fuel/air mixture. The electrode 58 is connected to the igniter 50 by an insulated wire 60 and is typically positioned to create a 1/8 gap with the venturi/diffuser assembly 24 which acts as ground.
To use this apparatus 10, a user rotates lever 30 so as to align enlarged exit apertures 32 of outer sleeve 26 with enlarged exit apertures 38 of inner sleeve 28. This large effective exit aperture reduces the gas flow velocity therefrom thereby reducing "blow off" during the pre-heating stage. Additionally, this aligns air entrainment openings 36 of outer sleeve 26 with the reduced portion of the pear-shaped air entrainment openings 41 of the inner sleeve 28 thereby increasing the richness of the fuel/air mixture as is desired during the pre-heating stage.
The user then opens valve 18 by turning knob 18 thereby allowing flow from the fuel source (not shown) through needle 22, valve 18, venturi/diffuser assembly 24 and out the exit apertures 32 and 38.
The user then activates the electrode 58 to ignite the fuel as it exits venturi/diffuser 24.
The user allows the ignited fuel to heat the catalyst assembly 46 for approximately sixty seconds or until the valve body 14 is warm to the touch. The user then rotates lever 30 thereby aligning the smaller diameter exit apertures 34 of the outer sleeve 26 with the larger diameter exit apertures of 38 of inner sleeve 28. Likewise, larger diameter exit apertures 32 of the outer sleeve 26 are aligned with the smaller diameter exit apertures 40 of inner sleeve 28 thereby creating effective exit aperture of the smaller diameter about the periphery of the venturi/diffuser assembly 24. This provides a higher exit velocity of the fuel mixture thereby preventing "flash back" during steady-state catalytic operation. Additionally, this aligns air entrainment openings 36 of outer sleeve 26 with the larger portion of the pear-shaped air entrainment openings 40 of the inner sleeve thereby increasing the leanness of the fuel air mixture as is required by steady-state catalytic operation. As the outer sleeve 26 rotates around inner sleeve 28, the exit apertures 32, 34, 38, 41 are temporarily blocked. If this blockage does not extinguish the flame, the user extinguishes the flame by turning valve 18 by knob 20. The valve 18 is likewise reopened and adjusted to a desired level so that fuel/air mixture exits venturi/diffuser assembly 24, impinges upon catalyst element 46 whereupon it is catalytically combusted.
Thus, in accordance with the above, the aforementioned objectives are effectively attained. | The present invention relates to a two stage venturi for a catalytic burner wherein a large exit aperture size and a small air entrainment opening are used to provide a low velocity, rich fuel/air mixture for the pre-heating process followed by a small exit aperture size and a large air entrainment opening to provide a high velocity, lean fuel/air mixture for the catalytic combustion process. Concentric rotating sleeves are used to vary the size of the exit apertures and the air entrainment openings. | 5 |
This application is a divisional of U.S. application Ser. No. 09/891,208 filed on Jun. 26, 2001, now U.S. Pat. No. 6,459,563, which is a continuation-in-part of provisional application 60/296,725 filed on Jun. 11, 2001, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The invention relates to aluminum surface mount capacitors having anode foil anodized in an aqueous phosphate solution.
BACKGROUND OF THE INVENTION
Surface mount electrolytic capacitors may be categorized as one of two basic types, those having powder metallurgy bodies, generally fabricated from tantalum or niobium powder, and those having foil coupon anode bodies. The foil coupons used in the latter type of capacitor are usually cut from high purity etched and anodized aluminum foil.
Typically, as shown in FIG. 1, coupons 1 cut from anodized foil are suspended from a bar 2 which provide mechanical registration and electrical connection. The coupons 1 are anodized to form anodic oxide on the cut edges of the coupons prior to coating with a conductive polymer/graphite/silver or other conductive paint and assembly into a finished capacitor complete with a molded or conformal insulating plastic case. The devices are then “aged” with voltage applied (to produce devices having stable electrical properties), tested and placed into reels for shipment to customers. Conductive polymer cathodes are preferred due to the relatively high resistivity and low thermal stability of traditional liquid electrolytes used to fabricate most leaded aluminum electrolytic capacitors. Conductive polymer cathode material is desirable over pyrolytic manganese dioxide (used in solid, surface mount tantalum capacitors) due to the degradation of the anodic oxide film which occurs when anodized aluminum is exposed to the temperatures and highly acidic conditions associated with pyrolytic manganese dioxide production from manganese nitrate solutions.
It was discovered that the production of stable surface mount, stacked-foil aluminum electrolytic capacitors having conductive polymer cathode material at high yields is rendered difficult by the instability of the aluminum oxide dielectric towards hydration. This instability can lead to problems in welding the anodes of the capacitors during assembly, elevated initial leakage, and leakage instability on storage in a humid environment.
Aqueous solutions of dicarboxylic salts, such as ammonium adipate, are used to produce the dielectric oxide on the vast majority of aluminum capacitor foil in use today. This oxide has excellent dielectric and capacitance properties, but it is highly susceptible to hydration. The anodized foil is usually coated with a thin phosphate layer by dipping in dilute phosphoric acid and heating the foil to dry the surface, etc. to help resist this hydration upon exposure to humidity, but the thin layer nature of this phosphate coating provides only limited resistance to hydration. The surface phosphate coating is sufficient to protect the foil during handling. For wet aluminum capacitors, where the foil is sealed in a can in contact with a substantially non-aqueous electrolyte, the surface hydration-resistant layer is also sufficient to keep the foil from hydrating during the life of the capacitor. Phosphate salts are also added to the liquid electrolyte to retard hydration. However, for solid electrolytic capacitors with aluminum oxide dielectrics and conductive polymer cathodes this surface hydration-resistant layer provides insufficient protection.
The solid aluminum electrolytic capacitors with conductive polymer cathodes are susceptible to hydration at several points in the manufacturing process. One such point is during the polymerization process. The catalyst/oxidizing agents/doping acids present during in situ production of the conductive polymer cathode layer have been found to be very destructive to the thin hydration-resistant layer on the anodic oxide surface. For example, U.S. Pat. No. 4,910,645 to Jonas describes the application of various polythiophenes to anodized aluminum substrates. In a preferred embodiment of Jonas, 3,4-ethylenedioxythiophene is applied using an iron III salt or an alkali metal or ammonium persulfate to oxidize the 3,4-ethylenedioxythiophene monomer. With either type of oxidizing agent, iron III salt or persulfate, the pH is reduced over the course of the polymerization reaction due to the liberation of acid; in the case of the persulfate salt, sulfuric acid is liberated. It is well known that sulfuric acid tends to have a corrosive effect upon aluminum depending upon the solution temperature and concentration, as well as upon the time of exposure.
Tests have demonstrated that the amount of sulfuric acid generated during the polymerization process is such that over ¾ of the phosphate coating present on commercially available capacitor anode foil may be dissolved from the surface of the surface of the foil during the conductive polymer application. After polymerization, the capacitors are washed in elevated temperature water (>50° C.) to remove polymerization byproducts. Because the surface hydration-resistant layer has been damaged, the capacitors are very susceptible to hydration at this point in the process. Hydration during the washing step can lead to inability to weld the capacitor to the lead frame and elevated leakage current, and, therefore, lower yield and quality.
After the process of assembly and molding during which the polymer/carbon/silver paint-coated anode coupons are cut from the support bars, stacked on a lead frame with the polymer-coated ends attached to the lead frame cathode via conductive adhesive and the uncoated ends welded to the lead frame anode portion via resistance or laser welding, the capacitor assemblies are then encapsulated by transfer molding, etc., to produce the finished capacitor. Unfortunately the assembly and molding or other insulating coating application process gives rise to numerous cracks in the dielectric. FIG. 2 shows an aluminum substrate 3 having an aluminum oxide coating 4 , a phosphate outer layer of aluminum oxide 5 and a crack 6 in the aluminum oxide. The crack 6 acts as an electrical leakage site when the devices are electrified.
In order to reduce the leakage current, the molded capacitors are electrified prior to testing. Co-pending application, U.S. Ser. No. 09/812,896, now abandoned, hereby incorporated by reference in its entirety, discloses that aging of aluminum capacitors containing conductive polymer cathodes are enhanced when the capacitors are moist and at an elevated temperature. The moisture contained within the molded devices appears to undergo electrolysis, providing oxygen to the cracks in the anodic oxide, producing a “plugged crack” 7 with fresh anodic oxide (FIG. 3 ). This results in reduced leakage current and oxidative degradation of the conductive polymer adjacent to cracks in the oxide. However, if the phosphate coating on the anodic oxide has been partially or wholly dissolved by the action of acids evolved during the polymerization process, the anodic oxide tends to undergo hydration during moisture exposure prior to electrifying or “aging”. This results in increased leakage current and reduced yields.
Similarly, if the anodic oxide is damaged more than slightly during the assembly and molding processes, the anodic oxide will undergo hydration from moisture seeping into cracks in the oxide and causing a lateral spread of oxide hydration 8 underneath the protective layer of phosphate coating the external anodic oxide surface as shown in FIG. 4 . Unless it is very carefully adjusted, modern, high-speed assembly equipment provides ample opportunity for damage to the anodic oxide. Once the anodic oxide has become hydrated, it is very difficult to reduce the device leakage current. If the hydration is sufficiently severe, the device capacitance will also be reduced due to the formation of bulky hydrated oxide in the pores of the foil. This can result in capacitor failure during storage or use.
The use of ammonium citrate in combination with ammonium phosphate edge formation electrolyte is disclosed in a co-pending application U.S. Ser. No. 09/874,388, now U.S. Pat. No. 6,548,324, which is hereby incorporated by reference in its entirety, as a way improving the hydration resistance of slit foil for use in solid aluminum capacitors with conductive polymer cathodes. This combination of electrolytes can restore hydration resistance in cracks in the oxide produced prior to polymerization and also form a hydration resistant oxide layer on the edges. However, damage to the outer hydration-resistant layer during polymerization and cracks in the oxide produced during the assembly and molding process occur after the edge formation process is performed. Thus, an aluminum oxide that is hydration resistant throughout the entire oxide volume is needed.
Phosphate is a well known hydration inhibitor for aluminum oxide. It can be used as an additive in solution to inhibit hydration (Vermilyea et al.) or incorporated into the oxide. As discussed above, incorporation of phosphate on the surface of aluminum oxide is well known for inhibiting hydration resistance of foil intended for use in wet aluminum electrolytic capacitors.
As an additive, phosphates are used in the so-called “operating electrolytes” of liquid electrolyte solution-containing (“wet”) aluminum capacitors (referenced in Alexander M. Georgiev's 1945 book, entitled: “The Electrolytic Capacitor,” page 41, (Ferris Printing Company, New York)).
To produce an anodic oxide containing phosphate on aluminum, good aqueous phosphate solution anodizing results are generally obtained with solutions having a pH of approximately 5 to 6 and at a temperature of approximately 90° C. Even under these conditions, phosphate anodizing tends to result in dissolution of a significant amount of the substrate aluminum. This dissolution tends to form deposits of aluminum phosphate on the walls and bottoms of the anodizing tanks used for the process, as well as on the surface of the foil. Additionally, anodizing in phosphate solutions usually results in anodized foil having about 10-15% lower capacitance for a given anodizing voltage than for the same foil (i.e., foil having the same etch structure) anodized in solutions containing carboxylic acid salts such as ammonium adipate. For these reasons, phosphate anodizing solutions have not been used to anodize aluminum for d.c. aluminum capacitors for decades, although some phosphate anodizing is used to produce anodized foil for a.c. motor-start capacitors, which are filled with a liquid or semi-solid glycol-borate electrolyte, where hydration resistance under reverse polarization is critical to proper device performance.
The sensitivity of standard carboxylic acid salt solution anodized capacitor anode foil to hydration, the corrosion by acids produced during conductive polymer application, and the tendency of mechanically damaged foil to undergo lateral hydration at cracks which undercuts the protective phosphate surface coating, all contribute to yield losses during the production of surface mount aluminum capacitors. Such problems mandate the implementation of careful control of polymer chemical solutions, assembly equipment set-up and speed, and humidity exposure before electrical aging of the finished devices, all of which tend to increase the cost of manufacture.
BRIEF SUMMARY OF THE INVENTION
The invention is directed to aluminum surface mount capacitors comprising one or more anode foil coupons wherein the aluminum foil coupons are initially anodized in an aqueous phosphate solution. The anodic oxide film produced in the aqueous phosphate anodizing solution provides extreme resistance to hydration and attack by corrosive anions.
The aluminum surface mount capacitors can be produced at high yield and having high stability. The stability of the oxide on phosphate-anodized coupons also minimizes the cost of production of the finished capacitors by maximizing yield and minimizing burn-in requirements for the finished devices.
The present invention is directed to an aluminum surface mount capacitor comprising at least one aluminum foil anode having a conductive polymer coating wherein the anode comprises a phosphate-anodized aluminum foil coupon. More particularly, the present invention is directed to anodizing an aluminum anode foil in an aqueous electrolytic solution comprising a phosphate.
The present invention is also directed to a method of preparing an anodized aluminum foil anode comprising immersing an aluminum foil coupon in an aqueous electrolytic solution comprising at least one phosphate and then applying an anodizing voltage to the aqueous electrolytic solution.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows aluminum coupons attached to a process bar.
FIG. 2 shows an aluminum substrate having a crack in the dielectric coating.
FIG. 3 shows the aluminum substrate of FIG. 2 with the crack in the dielectric coating “plugged.”
FIG. 4 shows the aluminum substrate of FIG. 3 with a growing area of hydrated oxide at the “plugged” crack.
FIG. 5 shows an aluminum substrate with a crack in the dielectric coating “plugged” in accordance with the instant invention with no hydration of the oxide.
FIG. 6 is a graph of the ratio of DC leakage current based on cumulative hours in an accelerated moisture test for a control group and a phosphate-anodized group.
DETAILED DESCRIPTION OF THE INVENTION
It was discovered that phosphate-containing aqueous electrolytic solutions produce anodic oxide dielectric coatings, which are very resistant to reaction with water. Aluminum anode foil coupons anodized in phosphate-containing aqueous electrolytic solutions and coated with conductive polymer cathode materials produce thermally and hydrolytically stable surface mount aluminum capacitors.
It is believed that, since the phosphate is incorporated throughout the oxide, not just as a surface coating, the oxide is resistant to hydration after corrosion by materials produced as by-products of in-situ polymer production, and lateral hydration due to cracks produced during assembly and molding.
It was also discovered that anodic aluminum oxide produced in aqueous phosphate solutions, both aqueous and partially non-aqueous (e.g., glycerine solutions,) is extremely resistant to reaction with water, even if the oxide is very thin such as oxide produced at 4-20+ volts. This is in contrast to anodic aluminum oxide, which is formed in aqueous dicarboxylic acid salts, such as ammonium adipate, and then treated with a surface layer of phosphate. The hydration resistance of the latter oxides are sufficient for wet aluminum electrolytic capacitors, but are not sufficient for solid electrolytic capacitors containing conductive polymer cathodes due to the corrosion of the outer oxide layer and cracks produced during assembly and molding.
In accordance with a preferred embodiment of the invention, an aluminum foil coupon is anodized in an aqueous electrolytic solution containing at least one phosphate. The phosphate may be one or more of an ammonium, alkali metal, or amine phosphate. Preferably the phosphate is ammonium phosphate.
The concentration of the phosphate in solution is about 0.01 wt % to about 10 wt %, preferably about 0.05 wt % to about 2 wt %, more preferably about 0.1 wt %. The pH of the electrolyte solution may be about 4 to about 8, preferably about 4.5 to about 7, more preferably about 5.
The electrolytic solution may contain other ingredients that do not affect the basic characteristics of the phosphate. Other ingredients include, but are not limited to glycerine.
The electrolytic solution is subjected to an anodizing voltage of about 2 volts to about 200 volts, preferably about 4 volts to about 100 volts. The temperature of the solution is about 20° C. to about 140° C., preferably about 50° C. to about 95° C., more preferably about 80° C. to about 90° C.
The anodized foil is then cut into coupons of appropriate size, and then the coupons are welded to process bars. The edges of the coupons are preferably anodized in an electrolytic solution to coat the cut edges with anodic oxide. Preferably, the edge anodizing uses the same phosphate electrolytic solution used for anodizing the aluminum anode foil.
The coupons are then coated with a conductive polymer, graphite, and silver paint prior to assembly into finished capacitors. Conductive polymers include, polypyrrole, polyaniline, polythiophene, and their derivatives. The conductive polymer is preferably acid-doped polyethylene dioxythiophene. The assembled, molded capacitors are then subjected to aging in a moist atmosphere.
EXAMPLE 1
The hydration resistance imparted by anodizing in phosphate solution is demonstrated by measuring the 25° C. leakage current through anodized coupons at the 80-90° C. anodizing voltage, subjecting the coupons to hydrating conditions, such as immersion in 70° C. water for 90 minutes, followed by a second determination of leakage current. An aqueous 10% ammonium adipate solution may be used for the leakage measurements.
Coupons anodized in phosphate solutions are found to give little or no increase in leakage current, while coupons anodized in ammonium adipate solution show a very substantial increase in leakage current of 2 to 3 orders of magnitude. Coupons cut from etched and adipate-anodized anode foil having a phosphate coating for hydration resistance, and “edge-formed” or edge-anodized in a 0.1% ammonium phosphate solution, exhibit hydration resistance nearly equivalent to that of coupons of phosphate-anodized foils. However, phosphate-coated, adipate-anodized foil coupons exhibit gross hydration if scratched, to simulate handling damage, prior to exposure to 70° C. water for 90 minutes.
It is believed that moisture enters the scratch and migrates into the adipate-derived anodic oxide undercutting the phosphate coating as depicted in FIG. 4 . The resulting hydrated oxide is visible as a black discoloration of the light gray oxide. As shown in FIG. 5, etched foil coupons anodized in phosphate solutions at 80-90° C. to form a phosphate-anodized aluminum oxide 9 , and then scratched prior to 70° C./90 minute hot water exposure, do not exhibit visible hydration 11 in the “plugged” crack 10 , nor a significant increase in leakage current.
The extreme resistance to hydration of even the scratched phosphate-derived anodic aluminum oxide films appears to be due to the presence of phosphate throughout the total anodic oxide layer thickness as indicated by recent spectrographic analysis of thin anodic films formed in phosphate. Although most of the phosphate is present in the outer portion of the film, some phosphate is present down to the metal/oxide interface. Thus, the standard aluminum anode foil of commerce, which is anodized in aqueous carboxylic acid salt solution and coated with phosphate in a post-anodizing step, might reasonably be expected to undergo degradation due to hydration when incorporated into surface mount capacitors. Surface mount capacitors prepared from etched capacitor foil, anodized in a phosphate solution, should be very resistant to hydration degradation.
EXAMPLE 2
Two groups of 47 μF/6 volt capacitors were prepared to demonstrate the superior moisture resistance of surface mount aluminum electrolytic capacitors containing aluminum anode coupons, anodized in a phosphate, compared with surface mount aluminum capacitors containing aluminum anode foil coupons, anodized in conventional carboxylic acid salt solution.
Group A—Control Parts
Control parts were fabricated using commercially available etched aluminum anode foil, which had been anodized in an ammonium adipate electrolyte solution and coated with phosphate as is the industry practice. The withstanding voltage of this foil was found to be approximately 17 volts by constant current testing in ammonium adipate solution at 50° C.
Group B—Phosphate-Anodized Parts
Phosphate-anodized parts were fabricated using commercially available etched aluminum anode foil. This foil was then anodized in-house, in a stainless steel beaker containing an electrolyte solution of 0.1 wt. % ammonium phosphate at a pH of approximately 5. The anodizing voltage was approximately 13 volts at 90° C. The anodized foil was found to have a withstanding voltage of approximately 17 volts by constant current adipate solution testing, as done with Group A.
After cutting the anodized foil into coupons of appropriate size, the coupons were welded to process bars and the edges of both groups of coupons were anodized in an identical manner to coat the cut edges with anodic oxide. The coupons were then coated with poly(3,4-ethylene dioxythiophene) conductive polymer, graphite, and silver paint prior to assembly into finished capacitors.
The assembled, molded capacitors were then subjected to aging in a moist atmosphere. The leakage current of the parts was measured at 6 volts following each 21 hour exposure to an accelerated moisture test at 121° C., 85% relative humidity, 2 atmospheres with no bias applied during the exposure. The results for several capacitors from group A and group B are given in FIG. 6 .
The data in FIG. 6 reveals that the capacitors fabricated from conventional carboxylic acid salt solution anodized anode foil are sufficiently damaged during polymer coating and assembly to undergo progressive hydration of the anodic oxide during post-molding humidity exposure and that this results in very elevated leakage current.
By contrast, the capacitors fabricated from anode foil anodized in a phosphate electrolyte solution showed no tendency to undergo hydration damage upon exposure to the same conditions as the capacitors fabricated from traditional carboxylateanodized commercial anode foil.
While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention. | Aluminum surface mount capacitors containing one or more anode foil coupons are initially anodized in an aqueous phosphate solution in order to produce an anodic oxide film having extreme resistance to hydration and attack by corrosive anions for the purpose of producing surface mount capacitors at high yield and of high stability. | 7 |
RELATED PATENT APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/174,467, filed Dec. 30, 1999, now abandoned and entitled “Multi-Railgun System Using Three Phase Alternating Current”.
TECHNICAL FIELD
The present invention is related to railguns and specifically to railguns powered by three phase alternating electrical current.
BACKGROUND OF THE INVENTION
Railgun macroparticle accelerators have presently impart high velocities (3 km/s and up) to launch packages or payloads with masses of a few grams to a few kilograms. There is now a large body of literature published giving details of what is required to do this. Some commercial and military applications desire launching masses of thousands of kilograms to velocities of approximately 100 m/s or so. One commercial application imparts velocities of approximately 100 miles per hour (45 m/s) to a carriage of mass 6000 pounds in the “Superman” ride at Magic Mountain, Valencia, Calif. Several military applications include launching of aircraft and “glide bombs” from naval ships and other sites such as ground based platforms.
FIG. 1 illustrates the general principal of a conventional railgun. During operation, electric current conducts through one rail 1 along the armature 2 and back to the power supply through the second rail 3 . Current flow is indicated by arrows drawn on the rails. The current in the rails produces magnetic fields shown as dashed ellipses 4 in FIG. 1 . The current in the armature 2 interacts with this magnetic field to give the electromagnetic (EM) railgun force on the armature 2 . The force F is generated outward regardless of current flow direction.
The railgun described herein is sometimes referred to as the “Bostic railgun”. The formula for calculating the railgun force, F, is:
F =½ L′I 2
where I is the current and L′ is the inductance gradient of the rail pair. The force is in Newtons when current is in amperes and L′ is in Henries per meter. Note that typically L′ is a very small number, around 0.5×10 −6 H/m, in some conventional applications. As such, large currents are needed to generate reasonable forces.
Two types of railgun applications include “high velocity” and “low velocity” railguns. The operating principle of both of them are substantially the same but their physical form and the means of delivering electric power to them can be quite different. High velocity railguns tend to be short with lengths of a few meters and short acceleration times of around one hundredth of a second. The accelerating current must be pretty much unidirectional because the “coasting time” at current reversal, if alternating current (AC) is used, is undesirable and leads to wasted gun length during launch. Low velocity railguns have much greater lengths and have acceleration times measured in seconds. Their allowable accelerations will be much lower because their launch packages include delicate components such as passengers.
The mechanical arrangement of a simple railgun is illustrated in FIGS. 2 and 3. The rails 5 are parallel and the launch package 6 and armature 7 are positioned between each rail. Rail support means and launch package guidance means are indicated at 8 as shown by the cutaway. Electrical connections are made at the breech end 9 of the rails. As is described in the case of the Bostic railgun, current goes up one rail, across the armature, and back down the other rail, as indicated by the larger arrows 10 . The railgun bore is shown as roughly square but it can be many different geometric shapes such as, rectangular, round, etc.
The directions of the EM forces are shown by the small arrows in FIG. 3 which is a plan view of the railgun. As well as driving the launch package or payload, the EM forces load the sliding contacts between the ends of the armature arms 11 and the rails 5 . Such loading is helpful in providing non-sparking contacts between the arm ends and the rails. Armatures are usually “sprung” between the rails to provide mechanical preloading as part of the required contact force. Electromagnetic forces also act to push the rails apart, an effect that must be resisted by the rails support structure.
SUMMARY OF THE INVENTION
In accordance with teachings of the present disclosure, a multi-railgun system using three phase alternating current is disclosed. In one form, a system operable to displace an object is provided. The system includes a housing having a pair of rails operable to conduct a current and an armature coupled between the rails and operable to conduct the current between the rails. The system includes a thrust arm coupled to the armature and extending through a slot in the housing. The thrust arm is operable to displace the object in response to the armature conducting the current and moving along the rails.
According to another aspect of the invention, a railgun accelerator system is disclosed. The system includes a plurality of railguns having a pair of rails operable to conduct a current and an armature positioned between the rails and operable to be displaced along the rails in response to the current. The system further includes distributed power sources positioned along the rails and operable to provide a single phase alternating current for each railgun.
According to a further aspect of the invention, a railgun acceleration system operable to displace an object is disclosed. The system includes a plurality of railguns having a pair of rails wherein each railgun is operable to conduct an associated single phase alternating current of a three phase alternating current. The system further includes a plurality of armatures positioned between the rails and operable to be displaced along the rails in response to the current and a thrust arm coupled to each armature and operable to displace the object.
One technical advantage of the present invention includes using three phase alternating current to produce a ripple free driving force for a railgun. As such, simplified embodiments for switching a railgun current “on” and “off” may be provided.
Another technical advantage of the present invention is to provide a railgun having plural stages. Each stage may provide a single phase of alternating current for each railgun to displace an object via thrust arms coupled to each railgun. Through using a single phase for each railgun, a substantially constant force may be realized for displacing the object.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete and thorough understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:
FIG. 1 is a general illustration of the railgun principal;
FIG. 2 illustrates a perspective view of a conventional railgun assembly;
FIG. 3 illustrates a top view of the railgun illustrated in FIG. 2;
FIG. 4 is a graphic illustration generally describing a current and force relationship in an AC powered railgun;
FIG. 5 illustrates one embodiment of a single phase AC powered railgun according to teachings of the present invention;
FIG. 6A illustrates a rear perspective view of one embodiment of a single phase AC powered railgun according to teachings of the present invention;
FIG. 6B illustrates a side perspective view of one embodiment of a single phase AC powered railgun according to teachings of the present invention;
FIG. 7 illustrates one embodiment of parallel array of railguns using multiple phased AC power according to teachings of the present invention;
FIG. 8 illustrates one embodiment of a circular array of railguns using multiple phased AC power according to teachings of the present invention;
FIG. 9 illustrates one embodiment of a multi-tier railgun according to teachings of the present invention;
FIG. 10 illustrates one embodiment of a multi-contact armature brush array according to teachings of the present invention; and
FIG. 11 illustrates one embodiment of a railgun using a multi-contact armature brush array according to teachings of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the invention and its advantages are best understood by reference to FIGS. 4-11. The present invention provides multiple phase AC powered railguns operable to displace an object. In one form, the multiple phase AC powered railguns include a series of stages operable to provide a single phase to an armature. As such, a substantially constant force may be produced through reducing undesirable ripple effects produced by single phase AC powered railguns. For example, FIG. 4 illustrates one short coming of using single phase AC to drive a railgun. The force F is proportional to current squared and remains positive and sinusoidal with double the frequency of the current sine wave. As the force F rises from zero to maximum and back twice every current cycle, a large “ripple” in the force results.
The present invention advantageously provides multi-phased AC power to reduce the “ripple” effect caused by single phase AC power. For example, three force curves F (not expressly shown) may be provided with their phase angles 120 degrees apart through using three phase AC power. As such, three force curves F may provide a substantially constant value equal to three times the mean value of one of the F curves thereby substantially reducing ripple in the resultant total force.
FIG. 5 illustrates one embodiment of a single phase AC powered railgun. A railgun, illustrated generally at 50 , includes a pair of rails 12 having a first stage 13 , a second stage 14 and a third stage 15 . AC power may be provided using power lines 16 coupled to each stage of railgun 50 . First stage 13 is coupled to power lines 16 using first stage transformer 30 and first stage switch 33 , second stage 14 is coupled to power lines 16 using second stage transformer 31 and second stage switch 34 , and third stage 15 is coupled to power lines 116 using third stage transformer 32 and third stage switch 35 . Railgun 50 may also include additional stages as needed. In one embodiment, power lines 16 may be a pair of high tension AC power lines and may be electrically connected to railgun 50 using matching voltage step-down (current step-up) transformers for transformers 30 , 31 , and 32 .
During operation, acceleration begins with the armature and thrust block (not expressly shown) at rest at the beginning of first stage 13 . When first stage switch 33 is closed, acceleration of the armature begins. As the armature moves into secondary stage 14 , second stage switch 34 closes and shortly thereafter first stage switch 33 opens to prevent current from second stage transformer 31 from shunting back down railgun 50 . Switching transformers continues in like manner as the armature enters subsequent stages and accelerates along rails 12 . As such, through using single phase AC power, opening and closing of switches 33 , 34 , and 35 within plus or minus a few cycles maintains optimal performance of railgun 50 thereby reducing critical timing which may be required for accelerating an object. For example, power to an active stage remains switched “on” until the armature enters the next stage, at which time power in the next stage is switched “on” and power to the previous stage is switched “off”.
In one embodiment, as the velocity of the armature and thrust arm increases (not expressly shown), higher voltage may be required to maintain an operating current reasonably constant. As such, each transformer secondary for transformers 30 , 31 , and 32 may have higher output voltages at higher stage numbers.
In one embodiment, standard commercial AC circuit breakers may be used to switch the AC power for each stage. Matching between the stages may be achieved using transformers and power may be provided to each stage using much higher voltage than required by railgun 50 . As such, switches 33 , 34 , and 35 may be positioned on the primary side of the transformers due to current being lower on the primary side.
FIG. 6A and 6B illustrate a rear and side perspective view of a single phase AC powered railgun according to one embodiment of the present invention. A low velocity railgun is illustrated and includes a pair of rails 36 coupled to a housing 37 . An armature 18 is positioned between rails 36 and is operable to displace an object (not expressly shown) using thrust arm 17 . Housing 37 includes a continuous slot in the top portion of housing 37 to allow thrust arm 17 to provide a force F to a payload or object external to the railgun.
In one embodiment, housing 37 may be cantilevered from the base to offset the EM repulsion force between rails 36 . Housing 37 may be arranged such that rails 36 are positively located by the recesses within housing 37 and through use of an upper lip along the top portion of rails 36 . Additionally, the base of housing 37 and the lower surfaces of the upper lips of housing 37 provide guidance surfaces for armature 18 .
During use, a single phase of multiple phase AC power may be provided to rails 36 at distributed points along rails 36 (not expressly shown). Armature 18 moves along rails 36 and provides a force to thrust arm 17 to displace an object or payload. In one embodiment, three-phase AC-power may be selectively coupled to rails 36 to provide a current having a phase which is approximately 120° apart from an associated railgun (not expressly shown). As such, a substantially constant force F may be provided by armature 18 to displace an object via thrust arm 17 .
FIG. 7 illustrates one embodiment of a parallel array of railguns operable to displace an object or payload. Several railguns, illustrated collectively at 51 , include thrust arms 17 operably coupled to displace an object or payload (not expressly shown). Magnetic field 19 may be provided by each railgun to create a force to displace an object or payload. Railguns 51 are preferably placed far enough apart so that there is enough space between them for their magnetic fields 19 to return.
FIG. 7 illustrates six railguns with power supply phases arranged as indicated by the numbers, 1 , 2 , 3 , 3 , 2 , 1 . A first phase is associated with the outer pair of railguns, a second phase is associated with adjacent inner pair railguns, and a third phase is associated with the inner pair of railguns. Other embodiments for configuring railguns 51 using associated single phase alternating current may be realized. For example, each phase for each railgun may be connected in the order 1 , 3 , 2 , 2 , 3 , 1 . As such, the forces generated by railguns 51 may be made symmetrical about a center line to reduce yawing torque associated with displacing an object using plural railguns.
During use, a selective phase may be used with each associated railgun as an armature for each railgun moves along each rail. For example, each pair may accelerate an object beginning with the phase as indicated in FIG. 7 and, along various point of each railgun, several sources may be provided at predetermined locations along an associated rail pair to provide a single phase current. As such, a parallel array of railguns using multiple phase AC power having distributed power sources may be used to displace an object.
FIG. 8 illustrates one embodiment of a circular array of railguns operable to displace an object or payload. The circular array may be used for gun-type applications and includes several railguns 20 circularly arranged with thrust arms 22 connected to a master block 21 at their center. Railguns 20 positioned across from each other use a current having the same phase. As such, a symmetrical yaw free force on master block 21 to displace an object. During use, railguns 20 having an associated AC phased power accelerate an object coupled to master block 21 and thrust arms 22 . In one embodiment, several power sources having the same phase may be provided for each railgun 20 along distributed points of each railgun 20 .
FIG. 9 illustrates one embodiment of a multi-tiered railgun for displacing an object or payload. A rear perspective view of a multi-tier railgun, illustrated generally at 53 , includes plural railguns 22 coupled to a thrust arm 41 for displacing an object or payload (not expressly shown). Each railgun 22 may include a separate phase for accelerating thrust arm 41 . Additionally, the magnitude of the current used to provide a force may contribute to a cross sectional dimension for each railgun 22 . For example, a minimum rail height may be required to carry a particular magnitude of current. Higher current in general may require larger bore railguns. Additionally, if the current per unit rail height becomes too large for a square bore geometry, then rail height associated with railguns 22 may be increased. As such, through providing a multi-tier railgun the current needed to displace an object may be reduced by dividing the current among each railgun 22 in the tiered arrangement illustrated in FIG. 9 .
During use, each railgun 22 may be electrically coupled in series to provide current on sub-rail basis. For example, the current for each railgun 22 may be reduced by a factor of one third of a given total current needed to produce a desired force. As such, some low velocity railguns require high voltages for displacing an object may benefit from using multi-tier railgun 53 .
FIG. 10 illustrates one embodiment of a multi-contact armature brush array operable to contact a rail of a railgun. A multi-brush armature, illustrated generally at 54 , includes several armature arms 24 including plural brush faces 23 for contacting a rail of a railgun (not expressly shown). Through using plural brushes 23 and armature arms 24 , increased levels of current may be conducted thereby providing an increased force for a given current per brush to displace an object (not expressly shown). For example, if the total current needed is 100,000 amperes, then the current should be shared between 20 brushes as illustrated by multi-brush armature 54 . In one embodiment, high electrical conductivity brushes which may include high conductivity materials such as copper, silver, etc., may be used to contact a railgun rail. As such, high current levels may be realized without causing sparking or arching at the interface between brush 23 and a railgun rail.
FIG. 11 illustrates one embodiment of a railgun using a multi-contact armature brush array. A railgun, illustrated generally at 55 , includes a pair of rails 25 coupled to an armature having nested armature arms 24 with plural brush faces 23 . The armature assembly further includes a bellows 27 coupled to a pair of bellows feet 28 and resilient wedges 29 .
During use, brush faces 23 and nested armature arms 24 conduct current between rails 25 and produce a force to move an object or payload (not expressly shown) coupled to thrust arm 26 . Nested armature arms 24 are provided in a trailing manner such that forces act in the direction to hold brush faces 23 in contact with rails 25 . However, as an AC signal passes through zero, the EM force for railgun 55 also approaches zero. As such, bellows 27 may provide additional force to maintain brush faces 23 in contact with rails 25 . For example, bellows 27 may be cylindrically shaped and foot 28 may be attached to both end faces of bellows 27 to spread the force produced by pressure in bellows 27 to a shape and size which matches the shape and size of the brush array. In one embodiment bellows 27 may have rectangular cross section having the same shape as the brush array thereby reducing the need for foot 28 .
In another embodiment, wedges 29 are made of a resilient material operable to transmit the force generated by the pressure in bellows 27 to the backs of the nested armature arms 24 . A gas pressure with bellows 27 may be externally controlled (not expressly shown) so that when set to zero, the armature can be easily slid from between the rails when necessary. Contact force can be changed by changing the pressure and pressure can be increased (decreased) when brush current is increased (decreased).
In one embodiment, an expansion stop may be provided to prevent over-expansion of bellows 27 should the armature assembly exit rails 25 with pressure still in bellows 27 . Bellows 27 , feet 28 , and wedges 29 may be coupled such that each component may move with the whole armature assembly. For example, a double-hinged coupling element (not expressly shown) may be coupled between armature arms 24 and bellows 27 .
Although the present invention has been described with respect to a specific preferred embodiment thereof, various changes and modifications may be suggested to one skilled in the art and it is intended that the present invention encompass such changes and modifications fall within the scope of the appended claims. | A railgun accelerator system powered by alternating current (AC) is disclosed. In one form, the system advantageously uses multiples of six railguns in parallel, allowing velocities of around 100 miles per hour to be imparted to a carriage of mass around 6000 pounds. Three phase AC power from a domestic grid or from a similar source may feed multiple power points along the length of the accelerator. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims the benefit of U.S. Provisional Application Ser. No. 60/761,880 filed on Jan. 25, 2006. The content of the aforementioned application is fully incorporated by reference herein.
TECHNICAL FIELD
[0002] This invention relates to prosthetic orthopedic implants, such as knees, hips, shoulders, ankles, discs, wrists, and other joint components. More specifically, this invention relates to a system and method of using a bonding material to create both immediate fixation between a prosthetic device and boney tissue and facilitate osteogenic growth of the boney tissue to the prosthetic material over time.
BACKGROUND
[0003] The human body has a variety of movable orthopedic joints such as the knee joint, hip joint, shoulder joint, and the like. These joints are formed by the intersection of at least two bones. The intersecting end of each bone has smooth articular surface that is comprised of cartilage. As a result of injury, wear, arthritis, disease or other causes, it is occasionally necessary to replace all or part of an orthopedic joint with an artificial implant. This procedure is referred to as a joint replacement or arthroplasty. For example, a total knee arthroplasty comprises cutting off or resecting the articular surfaces at both the distal end of the femur and the proximal end of the tibia. Complementary artificial implants are then mounted on the distal end of the femur and the proximal end of the tibia. Where only a portion of a joint is damaged, a partial joint arthroplasty can be performed. In this procedure, one or more artificial implants replace only a portion of a joint.
[0004] Although joint replacement is now a common procedure, conventional implants and related mounting techniques have significant shortcomings. One significant drawback of many joint replacements is for example, the many existing materials used in conjunction with orthopedic implant repairs. That is, existing methods and materials present many unsatisfactory characteristics. Existing orthopedic implants are “walled off” by the body by a fibrous capsule as the result of the foreign-body protective response of the tissue in contact with the implant. This fibrous membrane or capsule may develop between the prosthesis, cement, and or bone thereby preventing a strong physical bond between the bone and the implant. Failure of a joint repair or replacement is often attributed to movement made possible by the presence of the soft fibrous capsule or membrane. The capsule gets progressively thicker as the implant ages in the body and the implant becomes more mobile and the motion exceeds a critical level.
[0005] Presently, the average service life of a prosthetic implant is about 12-15 years. About 50% of implants inserted into a younger population (less than age 40) need revision during the lifetime of the patient, subjecting the patient to additional surgery and the risks that accompany such procedures. The success rate is even lower for revision implants. Furthermore, a second revision is often fraught with increased risk of infection and or loosening of the prosthesis.
[0006] Failure of these systems is often the result of wear debris; particles of, polymethylmethacrylate (PMMA) cement and particles of metal often are separated from the prosthesis and invoke an inflammatory response, bone resorption, and pain, ultimately resulting in a loosening and failure of the entire prosthesis and or premature polyethylene wear. This usually occurs within the joint capsule. The tissue response includes granulation of tissue by a progressive foreign-body reaction, transforming the joint into a mass of reactive inflammatory fibrous tissue that can extend to the ligaments and muscles. Large areas of bone can become poorly vascularized and necrotic. The final stages of deterioration include resorption of the supporting bone.
[0007] The cement used to attach joint components to surrounding tissue is typically a PMMA cement, which may be modified by chemical additions for radio-opacity or short-term antibiotic activity. PMMA cements or hardens by an exothermic polymerization reaction. Full strength is obtained quickly, (usually within 10 minutes) so the cement has the advantage of providing support and fixation immediately after setting. The working time and setting time can be partially controlled to provide the surgeon with a surgically practical cement. It was the development of PMMA cement that made joint replacement possible.
[0008] Nevertheless, there are problems associated with its use. Cement is a brittle material with little resistance to the repeated loads experienced by joints. Furthermore, it has little adhesive properties. It acts simply as a grouting agent to fill the gaps between prosthesis and bone helping the bone to support the prosthesis. Loading and motion of the joint can produce fracture of the cement and separation of the cement from the prosthesis. Furthermore, rubbing between the prosthesis and cement can produce wear particles that are not well tolerated by the bone and produce local bone loss. Such loss makes the prosthesis loose and produces pain and loss of function and may require re-operation. Further, such bone loss greatly increases the difficulty of revision to a new prosthesis and greatly reduces the chance of a successful result.
[0009] For aged patients with short life expectancy the replacement of “broken hips” with a PMMA-cemented prosthesis was an improvement when it was first invented. For patients having longer lifetimes, there are serious problems as discussed below. The American Society for Testing and Materials specifies the following requirements (ASTM F-451) for PMMA cement:
[0000]
Working time
5 minutes maximum
Setting time
5–15 minutes
Strength
70 MPa minimum
Solubility
0.05 mg/cm 3 maximum
Temperature rise
90° C. maximum
Intrusion
2.0 mm minimum
[0010] The solubility is limited to reduce both local tissue and systemic responses (e.g., when the monomer is distributed systemically it can lower blood pressure and affect organs.). The temperature rise is limited to reduce the cauterization and death of tissue overheated by the exothermic setting reaction. The hazards associated with solubility and temperature rise are well recognized.
[0011] The cement must fill the space between the prosthesis component and the bone. The geometry of the prosthesis component is shaped to aid the load-bearing requirement. The prosthesis-to-PMMA bond and the PMMA-to-tissue bond participate in this. The prosthesis-to-PMMA bond is controlled by the bond chemistry and prosthesis geometry. The PMMA-to-tissue bond is controlled by the tissue reactions and the body's physiological response. Initially this response includes bone resorption and then reconstruction through bone healing mechanisms to repair the damage produced by the surgical trauma and the temperature rise. When first inserted, the PMMA is smooth and undesirable tissue response is limited. With time, the PMMA cement can fatigue and become subject to fragmentation, and cracking releasing PMMA debris into the joint. The fragments of cement invoke an inflammatory response in the surrounding tissue and the cracks provide fresh surfaces for chemical exchange. The PMMA is weakened and subject to movement. Inflammation and tissue resorption further weakens the PMMA-to-tissue interface, ultimately, resulting in failure of the prosthetic device. The most common patient complaint associated with prosthesis failure and device loosening under stress (at one of the two bond sites) is progressive pain.
[0012] Another associated problem is that there is no physiologic bond or healing between the PMMA and the bone tissue. Instead a mechanical bond is achieved by forcing the fluid PMMA cement, under pressure, into the bone to penetrate pores and irregularities in the bone geometry. Sometimes a dam is inserted in the intramedullary space to restrict the longitudinal flow of the PMMA cement and obtain higher pressure and more radial flow. As an example, the subcortical region is an important load-bearing area composed of trabecular bone with the trabeculae oriented to transmit the load from one load-bearing region to another. The trabeculae are strong, thin regions of bone, forming the mesh-like interiors of spongy bone, commonly growing along stress lines. Their blood supply comes from the pores (also oriented by the trabeculae orientation) and from the intramedullary region, from attached tendons and from surrounding muscle, although the latter is usually less important. When a blood supply is removed by surgery, it must be compensated by other sources. This is not possible if the pores supplying blood are blocked by the PMMA cement.
[0013] Thus, inherent in the use of PMMA cement is an undesirable interference with blood supply. Although PMMA cements contribute immediate strength to the bone by filling the pores and supporting the trabeculae, such cements do not have enough strength when the trabeculae become seriously weakened, which is all but inevitable. Therefore the use of PMMA cement presents a basic limitation to the longevity of an implant. The cement breakdown and the PMMA-induced tissue response can prevent implants from lasting throughout extended life spans of patients. For these reasons a ten to fifteen year life is probably the maximum to be expected.
[0014] Another limitation of PMMA cement is the lack of bonding between metal and PMMA cement. Present practice usually provides a modified prosthetic undersurface to obtain mechanical interlocking between the cement and the prosthesis to attempt to compensate for this deficiency. Prosthetic devices used for cemented joint replacement are made of strong materials such as metal, cobalt-chromium or titanium, the surfaces of which are smooth and non-porous. While the use of such materials allows the new joint to withstand the stress of load-bearing, the smooth surface impedes bone ingrowth. As the prosthetic device ages and it becomes necessary to remove or replace the implant, it is difficult to remove the non-porous PMMA-bonded implant without fracture or damage to healthy bone. If PMMA cement is used with a prosthetic device having a porous surface, the problem of bone fracture and breakage upon removal or replacement is even more severe. Since most joint replacements will at some point require replacement, the issue of further damage to healthy bone is a serious concern for orthopedic surgeons.
[0015] The use of porous implants is another technique, which involves fixation of metallic prostheses to bone without the use of cement. This cement-less technique avoids the problems associated with cement but introduces its own problems. Cement fracture and its effects are eliminated. Metallic wear debris is reduced but is still present and can result in damage to bone and adjacent soft tissue. The most important new problem introduced by cement-less implants using porous prostheses is poor initial fixation. Cement provides instant, excellent, initial fixation. This fixation may degrade with time and use but it is usually excellent initially. Fixation of a porous coated device initially relies on a press fit, which may be difficult to achieve. Further, there is no initial impregnation of the fixation means into the bone and thus, such press fit is inferior to cement in attaching the prosthesis to bone. Biological ingrowth, or impregnation, relies on a stable connection between prosthesis and bone. If relative motion is not essentially eliminated, ingrowth will not occur, a fibrous capsule or membrane will develop and biological fixation will not be achieved.
[0016] In cases with cemented porous implants or implants with pre-coating to bond the implant to the cement, removal of the components again may not be easy. In these situations, it is often difficult to determine the plane between hard bone and hard cement, causing operative difficulties.
[0017] An important consideration in orthopedic surgery is the ability of bone to bond to the implant. It is well-known that hydroxyapatite and calcium phosphate are biocompatible and can provide a scaffold to allow bony ingrowth. This has led those in the field to investigate bone cements in which hydroxyapatite (HA) or modifications of HA are used to form a cement-like agent. Commercial cements are available based on precipitated HA or modified HA. However, in this application, bone substitute materials are used primarily to “fill space” or help in stabilizing bone, and can also in some situations be used as load-bearing members.
SUMMARY
[0018] As described above in the Background section, the concept of biologic bonding has been developed utilizing HA or hydroxyapatite spray. HA is sprayed onto the prosthesis during its manufacture and bonds onto the bone within 2-6 weeks eliminating the fibrous layer between cement and bone. This, however, does not provide any immediate fixation between prosthesis and bone. Immediate fixation still relies upon a press fit construct.
[0019] To overcome this and other problems inherent with current practices in the art, described herein is a new generation of bonded joint prosthesis systems that provide for immediate fixation and long term bone (osteogenic) ingrowth. That is, the following discussion introduces the broad concept of a using a biocompatible bonding material (not PMMA cement) capable of immediate fixation and more physiologic transmission of load between boney tissue and an implant, in conjunction with an orthopedic implant containing a porous surface, for joint replacement surgery. The bonding material will have the strength and rapid setting characteristics of PMMA cement, and will be incorporated by the supporting bone as the boney ingrowth and osteogenic growth processes take place. Accordingly, the bonding material and associated bonding prosthesis have the ability to adhere and conform to the implanted site and facilitate bone growth, to deter ingrowth of non-bone tissue into the implant site, to be immunologically tolerated by the host, and to serve as a framework for the newly forming bone tissue.
[0020] In one embodiment, the bonding material is comprised of calcium phosphate polymer that provides immediate hardening and biological bonding when interfacing an orthopedic implant to a boney tissue, thereby locking the implant to the bone. The biologic bond will also allow for bone in-growth over a period of 6-10 weeks providing long term fixation. The immediate bonding can eliminate the early loosening that commonly occurred with traditional uncemented total knee replacements.
[0021] The physical property of the surface of the implant which abuts and is bonded to boney tissue is preferably comprised of a metal material such as titanium or cobalt chrome. A portion of the implant surface has a textured, trabeculated or porous surface. In one embodiment, the optimum pore size of the porous surface is between 50 μm to 400 μm. The pore size may be spread over the load-bearing sections of the implant surface with the texture mirroring that of trabeculae boney tissue. Thus, the porous implant surface interfaces with the synthetic calcium phosphate polymer, and in turn is bonded to the surface of boney tissue thereby providing an artificial joint system.
[0022] Various embodiments of the present invention provide an orthopedic bonding system for artificial implants in which an artificial joint component with a porous surface is bonded to the surface of boney tissue by a biocompatible non-cement bonding material. Such a bonding material provides immediate strength and rapid setting characteristics of PMMA cement, as well as long term bone in-growth fixation between the prosthetic device and adjacent bone.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The detailed description is presented with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears.
[0024] FIG. 1 shows a bonded artificial joint system.
[0025] FIG. 2 shows a bonded knee joint system.
[0026] FIG. 3 shows a bonded hip joint system.
[0027] FIG. 4 shows a bonded shoulder joint system.
DETAILED DESCRIPTION
[0028] The following description details the concept of a using a biocompatible bonding material (not PMMA cement) in conjunction with an orthopedic implant containing a porous surface, whereby the porous implant can be bonded to a boney tissue, providing a superior method of orthopedic joint replacement overcoming many of the shortcomings of cement and cement-less joint replacement procedures currently performed. The biocompatible bonding material provides for immediate fixation of the implant to boney tissue; the bonding material will have the strength and rapid setting characteristics of PMMA cement. The bonding material of the present invention also provides immediate fixation and load bearing properties between implant and boney tissue, while promoting boney ingrowth. Accordingly, the bonding material and associated bonding prosthesis have the ability to rapidly adhere to and conform to the implanted site and facilitate bone growth, to deter ingrowth of non-bone tissue into the implant site, to be immunologically tolerated by the host, and to serve as a framework for the newly forming bone tissue.
[0029] The biocompatible non-cement bonding material and corresponding orthopedic implant configured with a porous surface may be recommended to medical personnel for use as an artificial joint system in orthopedic surgery. Such a system may include materials packaged together or materials that are available and packaged separately. In either event, materials can be sold with information and potentially training as to how they would be used together in surgery when performing partial or full joint replacement procedures. In one embodiment, the system includes an artificial joint component comprising a porous surface on at least a portion of the surface of the artificial joint component. The porous surface is for interface with a boney tissue. A non-cement biocompatible bonding material provides for immediate fixation of the porous surface of the artificial joint component to the boney tissue in situ. Components of the bonded artificial joint system are typically packaged aseptically so that they are suitable for use in surgery when removed from packaging.
[0030] Referring to FIG. 1 , there is shown a bonded artificial joint system 100 , including an artificial joint component 102 , a boney tissue 104 , and a bonding material 106 . The bonding material 106 bonds the artificial joint component 102 to the boney tissue 104 by interfacing a surface 108 of the artificial component with a surface 110 of the boney tissue.
[0031] The artificial joint component 102 is any suitable prosthetic device or material used for implantation in orthopedic surgery and is comprised of various materials such as chrome, titanium, ceramic, rubber and plastic, and any combination of such. As used herein, a prosthetic device is any artificial component used in joint replacement surgery, in which an orthopedic joint is either partially or fully replaced, such as but not limited to; knee replacement surgery, hip replacement surgery, shoulder replacement surgery, or any other joint replacement surgery involving replacement of joint tissue with an artificial component.
[0032] The physical property of the surface of artificial joint component 102 which abuts boney tissue 104 may be comprised of a metal material such as titanium, cobalt chrome, ceramic material or any combination of such materials or other materials suitable for use as part of the surface of an artificial joint component. The surface 108 of artificial joint component 102 is textured, trabeculated or porous. In one embodiment, the optimum pore size of the porous surface is between 50 μm to 400 μm. The pore size may be spread over the load-bearing sections of the implant surface with the texture mirroring that of trabeculae boney tissue.
[0033] Boney tissue 104 is a non-artificial component to which an artificial component is attached, and is part of a natural human joint system, such as the femur, tibia and patella of the knee, or any other boney tissue of a joint system, such as the hip, shoulder or spine. Boney tissue 104 is generally mechanically reshaped to provide the surface 110 for accepting, and bonding to, artificial joint component 102 upon the addition of bonding material.
[0034] Bonding material 106 is any suitable biocompatible agent that is strong or stronger than necessary to provide suitable orthopedic reinforcement for prosthetic implants while promoting osteogenic growth at the site of implantation. Bonding material 106 may be applied at the site of joint replacement, i.e., to the boney tissue prior to the insertion of artificial joint component 102 at the time of surgery, or bonding material 106 may be applied directly upon the porous surface 108 of artificial joint component 102 prior to the surgical procedure involving joint replacement.
[0035] In one embodiment, bonding material 106 is comprised of a calcium phosphate polymer that provides rapid, if not immediate, hardening and bonding thereby locking the artificial joint component 102 to boney tissue 104 . Calcium phosphate polymer is comprised of nonimmunogenic beta-tricalcium phosphate of nano-sized particles that enhances biologic bone ingrowth through a simultaneous process of Calcium phosphate boney incorporation. In this manner there is no loss of initial fixation during the boney ingrowth process and new bone growth. Calcium phosphate polymer integrates into existing bone, facilitating new bone formation in six weeks. The porosity and interconnected structure of the calcium phosphate polymers provides a scaffold for new bone ingrowth, vascularization, and osteoconduction. Suitable calcium phosphate polymer is available under the product name Vitoss® and can be purchased from Orthovita®, a company located at 45 Great Valley Parkway, Malvern, Pa. 19355.
[0036] In another embodiment, bonding material 106 is a terpolymer resin with combeite glass-ceramic reinforcing particles that provide immediate bonding to bone and improved mechanical strength of the prosthetic implant. One suitable glass-ceramic resin is comprised of combeite glass-ceramic particles; barium boro-aluminosilicate glass and amorphous silica, bound in a terpolymer resin comprised of bisphenol-a-glycidyl dimethacrylate, bisphenol-a-ethoxy dimethacrylate, and triethylene glycol dimethacrylate. Glass-ceramic bonding material provides biocompatible tissue interface, mechanical strength, direct bone apposition and bonding, and rapid setting for immediate load. Suitable glass-ceramic particle resin is available under the product name Cortoss® and can be purchased from Orthovita®, a company located at 45 Great Valley Parkway, Malvern, Pa. 19355.
[0037] Referring to FIG. 2 , there is shown an artificial knee joint arrangement 200 . In one implementation, artificial joint component 102 is a prosthetic device suitable for implantation to restructure an area of at least one of the femur 202 , tibia 204 or patella 206 . Bonding material 106 is interfaced between the surface 108 of the artificial joint component 102 and the boney tissue 104 .
[0038] The artificial knee joint 200 is immediately capable of load bearing and will undergo boney ingrowth, with new bone growth appearing in as early as six weeks. The method is suitable for partial or total knee replacements.
[0039] FIG. 3 shows a bonded hip joint prosthesis 300 . Boney tissue 104 is femur 302 and hip socket 304 , damaged portions of which are removed and replaced by bonding artificial joint component 102 to boney tissue 104 by bonding material 106 . The method is suitable for partial or total hip replacements.
[0040] In one embodiment, artificial joint component 102 is a metal ball and stem and is fixed to boney tissue of femur 302 by bonding material 106 .
[0041] In another embodiment artificial joint component 102 is a plastic or metal cup and is fixed to boney tissue 104 of hip socket 304 .
[0042] FIG. 4 shows a bonded shoulder joint prostheses 400 . Boney tissue 104 of the shoulder joint includes humerus 402 and scapula 406 , damaged portions of which can be removed and replaced by bonding artificial joint component 102 to boney tissue 104 by bonding material 106 . The method is suitable for partial replacements and resurfacing of the shoulder joint.
[0043] Reference herein to “one embodiment”, “an embodiment”, “an implementation” or “one implementation” or similar formulations herein, means that a particular feature, structure, operation, or characteristic described in connection with the embodiment, is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or formulations herein are not necessarily all referring to the same embodiment. Furthermore, various particular features, structures, operations, or characteristics may be combined in any suitable manner in one or more embodiments.
[0044] In the foregoing description, for purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without each specific example. In other instances, well-known features are omitted or simplified to clarify the description of the exemplary embodiments of the present invention, and thereby, to better explain the present invention.
[0045] The inventors intend these embodiments and implementations to serve as representative illustrations and examples. The inventors do not intend these embodiments to limit the scope of the claims; rather, the inventors have contemplated that the claimed invention might also be embodied and implemented in other ways, in conjunction with other present or future technologies. Thus, the embodiments described herein are to be considered in all respects only as exemplary and not restrictive. | A biocompatible bonding material is applied as an intermediary to attach prosthesis to boney tissue. The bonding material has the strength and rapid setting characteristics of PMMA cement, and is incorporated by the supporting bone as the boney ingrowth and osteogenic growth processes take place. In one embodiment, the bonding material is comprised of calcium phosphate polymer that provides immediate hardening and bonding, thereby locking the prosthesis to the bone. The biologic bond allows for bone in-growth over a period of weeks providing long term fixation. The immediate bonding can eliminate the early loosening that commonly occurred with uncemented joint replacements. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from Canadian Patent Application 2,701,422 filed Apr. 26, 2010 entitled A METHOD FOR THE MANAGEMENT OF OILFIELDS UNDERGOING SOLVENT INJECTION, the entirety of which is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to in-situ hydrocarbon recovery, including viscous oil. More particularly, the present invention relates to the management of an oil field undergoing solvent injection.
BACKGROUND OF THE INVENTION
[0003] Solvent-dominated in-situ oil recovery processes are those in which chemical solvents are used to reduce the viscosity of the in-situ oil. A minority of commercial viscous oil recovery processes use solvents to reduce viscosity. Most commercial recovery schemes rely on thermal methods such as Cyclic Steam Stimulation (CSS, see, for example, U.S. Pat. No. 4,280,559) and Steam-Assisted Gravity Drainage (SAGD, see, for example U.S. Pat. No. 4,344,485) to reduce the viscosity of the in-situ oil. As thermal recovery technology has matured, practitioners have added chemical solvents, typically hydrocarbons, to the injected steam in order to obtain additional viscosity reduction. Examples include Liquid Addition to Steam For Enhancing Recovery (LASER, see, for example, U.S. Pat. No. 6,708,759) and Steam And Vapor Extraction processes (SAVEX, see, for example, U.S. Pat. No. 6,662,872). These processes use chemical solvents as an additive within an injection stream that is steam-dominated. Solvent-dominated recovery processes are a possible next step for viscous oil recovery technology. In these envisioned processes, chemical solvent is the principal component within the injected stream. Some non-commercial technology, such as Vapor Extraction (VAPEX, see, for example, R. M. Butler & I. J. Mokrys, J. of Canadian Petroleum Technology , Vol. 30, pp. 97-106) and Cyclic Solvent-Dominated Recovery Process (CSDRP, see, for example, Canadian Patent No. 2,349,234) use injectants that may be 100%, or nearly all, chemical solvent.
[0004] At the present time, solvent-dominated recovery processes (SDRPs) are rarely used to produce highly viscous oil. Highly viscous oils are produced primarily using thermal methods in which heat, typically in the form of steam, is added to the reservoir. Cyclic solvent-dominated recovery processes (CSDRPs) are a subset of SDRPs. A CSDRP is typically, but not necessarily, a non-thermal recovery method that uses a solvent to mobilize viscous oil by cycles of injection and production. Solvent-dominated means that the injectant comprises greater than 50% by mass of solvent or that greater than 50% of the produced oil's viscosity reduction is obtained by chemical solvation rather than by thermal means. One possible laboratory method for roughly comparing the relative contribution of heat and dilution to the viscosity reduction obtained in a proposed oil recovery process is to compare the viscosity obtained by diluting an oil sample with a solvent to the viscosity reduction obtained by heating the sample.
[0005] In a CSDRP, a viscosity-reducing solvent is injected through a well into a subterranean viscous-oil reservoir, causing the pressure to increase. Next, the pressure is lowered and reduced-viscosity oil is produced to the surface through the same well through which the solvent was injected. Multiple cycles of injection and production are used. In some instances, a well may not undergo cycles of injection and production, but only cycles of injection or only cycles of production.
[0006] CSDRPs may be particularly attractive for thinner or lower-oil-saturation reservoirs. In such reservoirs, thermal methods utilizing heat to reduce viscous oil viscosity may be inefficient due to excessive heat loss to the overburden and/or underburden reservoir with low oil content.
[0007] References describing specific CSDRPs include: Canadian Patent No. 2,349,234 (Lim et al.); G. B. Lim et al., “Three-dimensional Scaled Physical Modeling of Solvent Vapour Extraction of Cold Lake Bitumen”, The Journal of Canadian Petroleum Technology, 35(4), pp. 32-40, April 1996; G. B. Lim et al., “Cyclic Stimulation of Cold Lake Oil Sand with Supercritical Ethane”, SPE Paper 30298, 1995; U.S. Pat. No. 3,954,141 (Allen et al.); and M. Feali et al., “Feasibility Study of the Cyclic VAPEX Process for Low Permeable Carbonate Systems”, International Petroleum Technology Conference Paper 12833, 2008.
[0008] The family of processes within the Lim et al. references describe embodiments of a particular SDRP that is also a cyclic solvent-dominated recovery process (CSDRP). These processes relate to the recovery of heavy oil and bitumen from subterranean reservoirs using cyclic injection of a solvent in the liquid state which vaporizes upon production. The family of processes within the Lim et al. references may be referred to as CSP™ processes.
Key Differences Between Thermal and Solvent-Dominated Recovery Processes
[0009] A key difference between a thermal recovery process and a SDRP is the value of the injected fluid. Solvent, such as hydrocarbon solvent, is more valuable than crude oil or steam. Therefore, fundamentally different approaches of measurement and analysis are required. Whereas in a steam-based process, measurement of temperature and injected volumes are important, in a solvent-dominated process, measurements of temperature are important largely for hydrate prevention, not viscosity reduction. Temperature may also be used to control the phase of the injectant. Measurements of produced solvent are important for maximizing solvent efficiency and solvent recovery.
[0010] Another key difference between thermal recovery processes and SDRPs is that heat may conduct through solids, whereas solvent may not. Solvent must be transported via flow through porous rock. Although monitoring of steam is important for understanding heat distribution, oil may flow even though steam has not directly contacted it. However, in a SDRP, viscous oil typically does not flow at a reasonable rate unless it has been mixed with solvent.
[0011] Another key difference between thermal recovery processes and SDRPs is the cost of fluid storage. In thermal processes, hot water is produced as at least a portion of the injected steam condenses underground and is produced back to the surface with oil. In a SDRP, the solvent must be compressed after production and stored locally at great cost if there is no injection capacity available. Measurement and analysis systems aimed at solvent storage reduction are important to making a SDRP economic.
Limitations of Prior Descriptions
[0012] Much of the research and patent literature that discusses viscous oil recovery processes focus on idealized processes as if they would be carried out for a single well, and does not discuss how to practically operate a SDRP at field scale to achieve certain efficiencies. Field scale operation demands that the key differences between thermal recovery processes and SDRPs be addressed using practical measurement and processes.
Solvent-Dominated Process Literature
[0013] U.S. Pat. No. 3,954,141 to Allen et al. entitled “Multiple Solvent Heavy Oil Recovery Method” offers a “Field Example” (col. 7, line 30) of the process, but nowhere within that example does the patent discuss the measurement of properties of the process, such as solvent production rate, for the digital management of the oilfield, such as increasing oil production or solvent efficiency.
[0014] Upreti et al. (Energy & Fuels 2007, 21, 1562-1574) wrote an up-to-date review article discussing the current state of understanding of Vapor Extraction (VAPEX), by far the most-studied SDRP. Upreti et. al. do not discuss the measurement of properties of the process, such as solvent production rate, for the digital management of the oilfield, such as increasing oil production or solvent efficiency.
[0015] Additional patents that disclose methods for the recovery of viscous oil using SDRPs include: U.S. Pat. No. 6,883,607 (Nenniger et al.); U.S. Pat. No. 6,318,464 (Mokrys); U.S. Pat. No. 5,899,274 (Frauenfeld et al.); and U.S. Pat. No. 4,362,213 (Tabor). These patents do not discuss methods for the digital management of oilfields undergoing solvent injection.
Digital Management of Oilfields
[0016] The digital management of oilfield operations is discussed in certain patent documents. These patents tend to fall generally into two groups—those that focus on digital methods and apparatus as a central aspect of the invention and provide examples of the method and apparatus being customized for a particular problem or class of problems; and those that focus on solving a specific problem and preferably, but not necessarily, employ digital oilfield apparatus.
[0017] Ramakrishnan et al. (U.S. Pat. No. 7,096,092) is one example of the first type. Ramakrishnan et al. discloses, “Methods and Apparatus for Remote Real Time Oil Field Management”. For example, they envision an apparatus comprising program modules for (FIG. 1) “analysis, alarm/message, acknowledgement, controller, and event logged.” Nowhere within Ramakrishnan et al. are SDRPs discussed or how their apparatus or any other particular apparatus for remote real time oil field management might be used to maximize oil recovery or otherwise improve an SDRP.
[0018] European Patent Document No. 1,355,169 to Baker Hughes Inc. entitled “Method and Apparatus for Controlling Chemical Injection of a Surface Treatment System,” ('169) is exemplary of the second kind. That patent document envisions sensors in the oil field whereby (col. 5, line 46) “the distributed sensors of this invention find particular utility in the monitoring and control of various chemicals which are injected into the well. Such chemicals are needed downhole to address a large number of known problems such as for scale inhibition and various pretreatments of the fluid being produced. “While the process described in '169 employs sensors in the oilfield, the general use of sensors is known. The specific use of measurement, analysis, and use of solvent-related data are not discussed in '169 which confines discussion to an “apparatus for controlling chemical injection of a surface treatment system for an oilfield well” (claim 1, col. 26, line 49).”
[0019] PCT Publication No. WO/2009/075962, to ExxonMobil Upstream Research Company, describes, according to the abstract, a method and system for estimating the status of a production well using a probability calculator and for developing such a probability calculator. The method includes developing a probability calculator, which may be a Bayesian network, utilizing the Bayesian network in a production well event detection system, which may include real-time well measurements, historical measurements, engineering judgment, and facilities data. The system also includes a display to show possible events in descending priority and/or may trigger an alarm in certain cases.
[0020] It would be desirable to use measurements of properties of the process, such as solvent production rate, in order to manage the oilfield, for instance for improving oil production or solvent efficiency.
SUMMARY OF THE INVENTION
[0021] It is an object of the present invention to obviate or mitigate at least one disadvantage of previous methods or systems.
[0022] Described herein is the use of field measurements to manage solvent-dominated oil recovery processes, for instance for increased oil recovery and/or solvent efficiency.
[0023] Disclosed is a method of using measurement devices and analysis methodologies to address important process differences between existing thermal oil recovery systems and SDRP technologies. Also disclosed is a method of measuring and analyzing properties of a SDRP process in order to improve cycle operation or solvent usage, detect the formation of solvent fingers, or minimize solvent storage needs.
[0024] Whilst these methodologies may be carried out using analog measurement systems and traditional approaches to field management, these processes are preferably carried out using digital, remote oilfield management apparatus designed and customized for carrying out these methodologies.
[0025] Because oilfield management of a SDRP has not been carried out except for pilot-scale projects, the particular limitations of earlier disclosures cannot be appreciated except to understand how, if extended to the scale envisioned herein, those methods would not be effective. For instance, past pilots have used trucks to deliver the solvent to the field. At commercial scale, such a solvent delivery scheme may not be feasible.
[0026] In a first aspect, the present invention provides a method of managing a hydrocarbon field undergoing solvent injection, the method comprising: (a) obtaining data from sensors in the hydrocarbon field indicative of fluids produced from each of at least two wells in the hydrocarbon field; (b) using the data, estimating both the flow rate of the fluids produced from each of the at least two wells and the solvent concentration of the fluids produced from each of the at least two wells; (c) using the data, determining, for at least one of the wells, whether a solvent injection rate or a fluid production rate should be adjusted; and (d) adjusting management of the hydrocarbon field in response to the determination of step (c). In this aspect, the following features may be present. Step (d) may comprise adjusting the solvent injection rate or the fluid production rate. The estimating of step (b) may comprise calculating a sum, average, difference, variance, or ratio of data from the at least two wells. The data may comprise temperature, pressure, fluid phase fraction, flow rate, density, electrical conductivity, electrical inductance, species concentration, or more than one of the foregoing. Step (b) may comprise estimating flow behavior comprising an aqueous liquid phase rate, a gaseous phase rate, a non-aqueous liquid phase rate, a solvent rate, a hydrocarbon rate, a gas fraction, a solvent fraction, a hydrocarbon fraction, or a hydrocarbon-solvent ratio. The at least two wells may comprise at least two groups of wells, wherein the data is obtained for each of the at least two groups of wells. The method may further comprise: estimating a difference in flow behavior between the at least two wells; comparing the difference in flow behavior to a maximum acceptable value to determine whether the difference should be reduced; and where the difference is less than the set value, adjusting at least one injection or production variable to reduce the difference. The flow behavior may be solvent production rate. The method may further comprise: estimating, using the data, a solvent efficiency measure based on solvent and hydrocarbon flow rates for the at least two wells, which wells feed a solvent recycle line; and reducing solvent flow rate of a least efficient well by reducing its gross production rate. The method may further comprise using the data, adjusting the production rate of one or more of the at least two wells to reduce a difference in production flow behavior between two of the at least two wells. The solvent injection may be performed cyclically and the flow behavior may be analyzed on a cycle basis. The cycle basis may be temporally defined from a beginning of solvent injection into a well through an end of a following production period. The flow behavior may be analyzed using maximums or minimums determined over a previous time period. The flow behavior may be analyzed using net quantities. The flow behavior may be analyzed using variance measures.
[0027] In further aspect, the present invention provides a method of managing a hydrocarbon field undergoing solvent injection, the method comprising: (a) obtaining data from sensors disposed at a hydrocarbon field indicative of bottomhole pressure in each of the at least two wells; (b) using the data, estimating bottomhole pressure in each of the at least two wells; (c) using the data, determining a change in covariance of the bottom pressure between the at least two wells to determine whether a solvent connection has formed between the at least two wells; and, (d) adjusting management of the hydrocarbon field in response to the determination of step (c). In this aspect, the following features may be present. The sensors may measure bottomhole pressure. Step (d) may comprise adjusting an injection or a production rate of one or more of the at least two wells to reduce solvent flow through the connection formed between the at least two wells to increase hydrocarbon production or solvent efficiency.
[0028] In further aspect, the present invention provides a method of managing a hydrocarbon field undergoing solvent injection, the method comprising: (a) obtaining data from sensors disposed at the hydrocarbon field indicative of available solvent supply capacity; (b) using the data, estimating available solvent supply capacity; and (c) combining the estimated available solvent supply of step (b) with static data to determine whether the available solvent supply capacity is above or below a desired value, and optionally estimating by what amount. In this aspect, the following features may be present. The static data may comprise storage tank capacity, maximum solvent purchase requirement, minimum solvent purchase requirement, maximum pump injection capacity, and flowline capacity. The sensors may measure solvent supply flow rate. The method may further comprise, where the available solvent supply capacity is above the desired value, increasing total solvent injection or storing solvent on the surface; and where the available solvent supply capacity is below the desired value, decreasing total solvent injection or withdrawing solvent from surface storage. The method may further comprise, based on step (d), estimating how much solvent to purchase, or how much solvent to store in, or retrieve from, on-site storage facilities, and/or how to distribute solvent amongst two or more injection wells.
[0029] In a further aspect, the present invention provides a system for managing a hydrocarbon field undergoing solvent injection, the system comprising: (a) sensors for sensing one or more properties indicative of fluids produced from each of at least two wells; and (b) a computer system for: receiving data from the sensors; estimating both flow rate of the fluids produced from each of the at least two wells and solvent concentration of the fluids produced from each of the at least two wells; determining, using the data, for at least one of the wells, whether a solvent injection rate or a fluid production rate should be adjusted; and adjusting management of the hydrocarbon field in response to the determination.
[0030] In a further aspect, the present invention provides a system for managing a hydrocarbon field undergoing solvent injection, the system comprising: (a) sensors for sensing one or more properties indicative of fluids produced from each of at least two wells; and (b) a memory having computer readable code embodied thereon, for execution by a computer processor, for: receiving data from the sensors; estimating both flow rate of the fluids produced from each of the at least two wells and solvent concentration of the fluids produced from each of the at least two wells; determining, using the data, for at least one of the wells, whether a solvent injection rate or a fluid production rate should be adjusted; and adjusting management of the hydrocarbon field in response to the determination.
[0031] In a further aspect, the present invention provides a computer readable memory having recorded thereon statements and instructions for execution by a computer processor to carry out a method described herein.
[0032] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
[0034] FIG. 1 is a flow chart illustrating a method in accordance with a disclosed embodiment;
[0035] FIG. 2 is a schematic of a measurement system in accordance with a disclosed embodiment; and
[0036] FIG. 3 is another schematic of a measurement system in accordance with a disclosed embodiment.
DETAILED DESCRIPTION
[0037] The term “viscous oil” as used herein means a hydrocarbon, or mixture of hydrocarbons, that occurs naturally and that has a viscosity of at least 10 cP (centipoise) at initial reservoir conditions. Viscous oil includes oils generally defined as “heavy oil” or “bitumen”. Bitumen is classified as an extra heavy oil, with an API gravity of about 10° or less, referring to its gravity as measured in degrees on the American Petroleum Institute (API) Scale. Heavy oil has an API gravity in the range of about 22.3° to about 10°. The terms viscous oil, heavy oil, and bitumen are used interchangeably herein since they may be extracted using similar processes.
[0038] In situ is a Latin phrase for “in the place” and, in the context of hydrocarbon recovery, refers generally to a subsurface hydrocarbon-bearing reservoir. For example, in situ temperature means the temperature within the reservoir. In another usage, an in situ oil recovery technique is one that recovers oil from a reservoir within the earth.
[0039] The term “formation” as used herein refers to a subterranean body of rock that is distinct and continuous. The terms “reservoir” and “formation” may be used interchangeably.
[0040] The expression “undergoing solvent injection” means in situ oil recovery using a SDRP. While CSDRP is discussed in certain detail, unless stated otherwise, embodiments relate to SDRP that may or may not be cyclic.
[0041] The expression “sensor” refers to any device that detects, determines, monitors, records, measures, or otherwise senses the absolute value of, or change in, a physical quantity. Non-limiting examples of measurements performed by the sensors include pressure, temperature, optical property (such as refractive index or clarity), salinity, density, viscosity, conductivity, chemical composition, force, and position. As these sensors are known in the art, they are not discussed in any detail herein.
System Overview
[0042] FIG. 1 depicts an overview of one embodiment. A measurement system ( 101 ) comprises sensors ( 102 ) and a measurement recording system ( 103 ). Examples of sensors include flowmeters, pressure gauges, densitometers, and thermometers. In one embodiment, the sensors include flowmeters and pressure gauges. An example of a measurement recording system ( 103 ) is a computer system comprising the ability to receive, store, and at least partially analyze data from the sensors, and to provide access to the data, or the at least partially analyzed data.
[0043] The data are in digital form as either data ( 104 ) or partially analyzed data ( 105 ). Examples of data include raw, compressed, filtered, or subsets of the data. Examples of partially analyzed data include rounded data, sums, averages, maximums, minimums, variance measures, net quantities, or other products of mathematical operators.
[0044] The data or partially analyzed data are retrievable by a central location ( 106 ), preferably using electronic means, and more preferably using real-time or near real-time transmission. In this context, real-time means continuously streaming and near real-time means a transmission frequency of at least daily. At the central location, the data analysis is finalized ( 107 ) and used to make a field management decision ( 108 ) which is subsequently communicated to the field ( 109 ).
[0045] The expression “sensors disposed at the oil field” includes sensors in the facilities associated with the oil field.
[0046] Described below are embodiments relating to managing a SDRP.
Solvent Rate Measurement System
[0047] FIG. 2 depicts the solvent flowstreams of one embodiment of a SDRP. The SDRP in this embodiment employs a pipeline ( 201 ) to supply solvent, trucked-in solvent supply ( 202 ), one or more solvent storage tank(s) ( 203 ), one or more producing wells ( 204 ), one or more injecting wells ( 205 ), a subterranean reservoir ( 206 ), and flow lines and measurement devices connecting them. For the sake of artistic convenience, FIG. 2 illustrates five producers, five injectors, one reservoir, one pipeline, and one tank. Those skilled in the art will recognize conceivable alternatives such as dispensing with one or more elements, such as the trucked solvent ( 202 ), pipelined solvent (pipeline 201 ), tank(s) ( 203 ), some portion of the measurement system ( 210 to 217 ), or other permutations of flowline connectivity. Those skilled in the art will recognize conceivable alternatives such as adding additional elements, such as additional reservoirs ( 206 ), trucks ( 202 ), or tanks ( 203 ), or measurement locations, to name but a few.
[0048] FIG. 2 shows that measurement devices (“measurement devices” is used interchangeably with “sensors”), denoted “M”, are affixed to various strategic locations in the flowline system. The measurement devices record the rate of pipelined solvent supply ( 210 ), the producing wells' solvent production rates ( 211 ), the injecting wells' solvent injection rates ( 212 ), the total produced solvent supply ( 213 ), the combined pipelined and produced solvent supply ( 214 ), the total injected solvent rate ( 215 ), the combined available solvent supply ( 216 ), the flow rate to or from storage ( 217 ), and the intermittent (intermittent nature denoted with dashed line) trucked-in solvent supply rate ( 218 ). While measurements of rate have been discussed, measurements of pressure, density, and temperature, for example, may also, or alternatively, be made.
[0049] In order to measure solvent rates from fluid streams that comprise fluid mixtures, separation processes or concentration measurement may be required. Measurement in portions of the produced fluids system is also therefore employed to achieve the measurements envisioned in FIG. 2 .
Produced Fluid Measurement System
[0050] FIG. 3 depicts one embodiment of a produced fluids measurement system for a SDRP. The produced fluid ( 300 ) from one or more wells is separated using a separator (Sp) ( 301 ) into aqueous ( 302 ), gaseous ( 303 ), and liquid hydrocarbon ( 304 ) phases. The aqueous stream ( 302 ) is disposed of ( 316 ). The gaseous flowstream ( 303 ) is further separated, using separator (Sp) ( 308 ) into its components, natural gas ( 310 ), oil ( 311 ), and solvent ( 312 ). The liquid hydrocarbon flowstream ( 304 ) is further separated into its components, natural gas ( 310 a ), oil ( 311 a ), and solvent ( 312 a ) using separator (Sp) ( 308 a ). The component streams are recombined. The separation processes need not be one hundred percent efficient. For example, it is acceptable to have concentrations (for example, no more than a few mass percent) of solvent remaining in the oil phase, and vice versa.
[0051] The combined gaseous stream ( 313 ) and oil stream ( 314 ) may be sold. In this embodiment, the combined solvent stream ( 315 ) is recycled as a flowstream shown in FIG. 2 ( 213 ). The precise destination of the combined produced solvent stream ( 315 ) depends upon the lifecycle phase of the SDRP oilfield development. During the ramp-up of the field development all of the produced solvent may be recycled as injected solvent ( 213 ). During the wind-down of the SDRP-produced oilfield, a portion of the produced solvent may be recycled as injected solvent and the remaining portion sold. When all solvent injection in the oilfield has ceased, all of the produced solvent may be sold.
[0052] It is not typical oilfield practice to carry out continuous separation of the individual flow streams for every well—they are usually combined at a manifold into one fluid stream ( 300 ) prior to separation. However, the instant process makes use of component and phase flow rates for individual wells. In the described process, the frequency of these measurements need not be continuous. For example, a test separator could be used on a daily basis to measure the individual phase ( 302 , 303 , 304 ) and component ( 310 , 311 , 312 ) flow rates for every well. Understanding the solvent and oil production rates for a well undergoing a SDRP is important for maximizing performance.
[0053] The produced fluid measurement system may also have devices to control field operations such as valves, pumps, and other fluid control devices. Common fluid control devices include valves to choke flow, rotary pumps, and programmable logic controllers. Programmable logic controllers may use a measurement from the produced fluid measurement system in order to automatically control a valve, a pump, or other fluid control device.
Substantially Time Varying Measurements
[0054] The measurement systems described in FIGS. 2 and 3 are meant to capture primarily time varying data. For reasons of both convenience and scientific merit, it is commonplace to process the raw, measured, time-varying data. As used herein, the term “analyzed data” is used interchangeably with “products of mathematical operators.” These quantities are computed from time-dependent variables and change with time. Such measures may be computed over a period of time. For example, a running average is an example of analyzed data derived through mathematical operation on a time series variable. Examples of partially analyzed data include rounded data, filtered (decimated) data, sums, averages, ratios, maximums, minimums, variance measures, net quantities, or other products of mathematical operators.
[0055] A particular way to aggregate time varying data that is useful for analyzing cyclic SDRPs (CSDRPs) is to compute averages or sums on a cycle basis. For example, computations of solvent efficiency require a measurement of oil production per solvent volume. One measure is the produced oil to injected solvent ratio, or OISR. This computation is carried out by computing the volume of oil obtained from a well during the production phase of a cycle and dividing it by the volume of solvent injected during the injection phase of the same cycle. An important economic choice in CSDRPs is whether or not to carry out another injection cycle; once the injection phase of the cycle is over, there is little additional cost to complete the cycle. In a SDRP that is not a CSDRP, a solvent efficiency measure that is not cycle-based may be appropriate, for example a weekly calculated OISR.
Substantially Non-Time Varying Measurements
[0056] As used herein, the terms “static data”, “constraints”, “system parameters”, and “facilities data” refer generally to related values that do not change continuously over time and remain fixed for a substantial portion of the SDRP. For example, the state of the choke on a flow line remains fixed in one position and does not change until it is fixed in a different position by an operator. These kinds of data are discrete and typically associated with some facility. System parameters that seldom vary with time include, by way of example, storage tank capacity, maximum and minimum solvent purchase requirements, maximum pump injection capacity, flowline capacity, and other system operational limits or setpoints. While different SDRP systems are subject to different constraints and the same system may be subject to different constraints at different times, all SDRP systems have substantially non-time varying data that are important for efficiently using solvent.
Data Access
[0057] Although the methodology described could be carried out using traditional field-based methods, such as storing the measurements in a written or electronic file and transporting them to persons who analyze them and make field management decisions, the process is optimally practiced using remote monitoring of the measurements. For example, it is preferable that field staff carry out the measurement procedures by maintaining and operating the equipment that is used to obtain, store, and provide access to (and optionally to transmit) the measurements to engineers based outside the field, for example in an office.
Specific Examples of how the Process May be Used to Accomplish a Valuable Result
[0058] The digital oilfield management and measurement system just described may be used to adjust production rates of one or more wells to reduce the difference in production flow behavior of at least two production wells. Flow behavior may include all of the measurements discussed thus far and includes quantities such as phase and component flow rates. For example, the solvent production rate is one kind of flow behavior. Another kind of flow behavior is the total production rate. It is desirable to control the flow behavior of the solvent in particular because of its economic value since it is typically more valuable than the produced oil.
[0059] One difference in flow behavior might be a difference in gas production between at least two production wells. SDRP wells may produce both native gases and solvent gas depending upon the operating pressure and reservoir fluid characteristics. Gas production is oftentimes detrimental to oil recovery, and natural gas production in particular is undesirable as it may signal the bypassing of oil and is less valuable than solvent gas. The fraction of gas (native or solvent) in the produced stream may be computed by measuring the gas production stream ( 303 ) in relation to the other production streams ( 302 , 304 ). If the gas fraction rises too high, the producing bottomhole pressure could be raised in an attempt to prevent gas breakthrough. When a SDRP is producing at pressures below the vapor pressure of the solvent, it is expected that solvent gas will be produced. The recovery of solvent gas is required for SDRPs to be economic. Distinguishing between native gas and solvent gas is therefore important. The measurement system is preferably designed to distinguish between the two, as does the measurement system of FIG. 3 .
[0060] Another difference in flow behavior between two or more wells might be the solvent production rate. The capacity of the flowline carrying the combined pipelined and produced solvent supply ( 214 ) is necessarily of limited capacity. If it were to reach maximum capacity, it would be desirable to choke back, or decrease, the flow rate of solvent from the wells with the lowest solvent efficiency. The wells have differential solvent production rates and it is desirable to know which wells should be choked back. To accomplish this desired flow reduction the following may be carried out: (1) calculate a solvent efficiency measure using the solvent and oil flow rates for every well that feeds the solvent recycle line; (2) rank all the wells from most to least solvent efficient; and (3) reduce the solvent flow rate of the least efficient well by reducing its gross production rate. Gross production rate may be decreased by increasing the producing pressure of the well.
[0061] Cyclic SDRPs in particular should make use of measures of solvent efficiency to decide when to switch from production to injection. Using an embodiment of the instant invention, the field management decision of when to switch from production to injection could be carried out using these steps: (1) measure and transmit a well's solvent and oil produced volumes to a central office on a near real-time basis; (2) calculate solvent efficiency measures such as oil to solvent ratio on a cycle basis; (3) if the well is no longer as efficient as desired, switch to production or initiate other action; and (4) communicate decision to field.
[0062] The supply rate of the pipeline ( 201 ) is necessarily of limited capacity and also of preferably constant rate within some contractually specified variation. In order to stay within the specified downside variation, it is necessary to increase injection of solvent into wells or store solvent. To accomplish this control, the following may be carried out: (1) measure the flowrate ( 210 ) of the supply and determine if the flowrate is nearing the downside limit or the upside limit; (2) if the flowrate is nearing the downside limit, then increase total injection to the reservoir ( 206 ) or store solvent on the surface (for example, surface tank(s) 203 ); and (3) if the flowrate is nearing the upside limit, then decrease total injection to the reservoir ( 206 ) or withdraw solvent from the surface tank(s) ( 203 ).
[0063] In CSDRPs, as solvent is injected into the formation, solvent fingers form which can, relatively early in the life of the field, stretch out 100 meters or more and connect up with other wells. If the well injection and production cycles are not sufficiently synchronized, solvent may rapidly flow from one well to the other when one is on production and the other is on injection and have a negative impact on solvent efficiency and consequent oil recovery. Such orientation is notable because two nearby wells will experience injector-to-producer channeling of injected solvent if they are operated out-of-phase. Even though injected solvent and injected steam both have adverse mobility ratios when injected into highly viscous oil, the channeling effect is particularly acute in solvent-dominated processes, more so than in steam-based processes, and more so than is generally appreciated by those skilled in the art.
[0064] Two nearby wells may experience injector-to-producer channeling of injected solvent if they are operated out-of-synch, where one well is injecting while the other is producing. Channeling leads to fluid communication. Fluid communication between two neighboring wells is said to have occurred when a pressure change recorded at one well is also detectable at a neighboring well. The stronger the correlation in the pressure changes, the stronger the communication. Two wells in fluid communication are said to be “connected”. A change in pressure covariance between two or more wells may indicate the formation of a solvent channel between the two or more wells. If covariance is detected, the two wells can be operated substantially in-synch such that the wells are operated either both on injection or both on production, but not opposite. Referring to FIG. 1 , another way to accomplish communication reduction is to transmit the pressure data in raw ( 104 ) or partially filtered or decimated form ( 105 ) to a central office ( 106 ) were the data is analyzed for covariance ( 107 ) and a decision is made ( 108 ) to, for example, decrease the injection rate at one of the two wells.
[0065] Reducing the amount of solvent stored on-site is important because solvent storage is expensive. Envisioned solvents, such as light hydrocarbons, must be stored at high pressure in order to be a liquid and therefore storable in a tank. High-pressure storage is more expensive than storage at atmospheric pressure because the tank walls must be thicker than for the equivalent volume at atmospheric pressure. Transmission of the amount of solvent in storage, in combination with knowledge of the tank volume, allows calculation of the tank ullage. Operators planning the dispatch of a solvent delivery truck or planning for an injection rate increase can operate more efficiently with real-time knowledge of the tank ullage. The tank is spare solvent injection supply and accurate, remote knowledge of the current spare capacity (the current solvent volume in the tank) enables the tank to be refilled just-in-time. This mitigates the need to build the tank larger than is truly needed.
Solvent Composition
[0066] The solvent may be a light, but condensable, hydrocarbon or mixture of hydrocarbons comprising ethane, propane, or butane. Additional injectants may include CO 2 , natural gas, C 3+ hydrocarbons, ketones, and alcohols. Non-solvent co-injectants may include steam, hot water, or hydrate inhibitors. Viscosifiers may be useful in adjusting solvent viscosity to reach desired injection pressures at available pump rates and may include diesel, viscous oil, bitumen, or diluent. Viscosifiers may also act as solvents and therefore may provide flow assurance near the wellbore and in the surface facilities in the event of asphaltene precipitation or solvent vaporization during shut-in periods. Carbon dioxide or hydrocarbon mixtures comprising carbon dioxide may also be desirable to use as a solvent.
[0067] In one embodiment, the solvent comprises greater than 50% C 2 -C 5 hydrocarbons on a mass basis. In one embodiment, the solvent is primarily propane, optionally with diluent when it is desirable to adjust the properties of the injectant to improve performance. Alternatively, wells may be subjected to compositions other than these main solvents to improve well pattern performance, for example CO 2 flooding of a mature operation.
Phase of Injected Solvent
[0068] In one embodiment, the solvent is injected into the well at a pressure in the underground reservoir above a liquid/vapor phase change pressure such that at least 25 mass % of the solvent enters the reservoir in the liquid phase. Alternatively, at least 50, 70, or even 90 mass % of the solvent may enter the reservoir in the liquid phase. Injection as a liquid may be preferred for achieving high pressures because pore dilation at high pressures is thought to be a particularly effective mechanism for permitting solvent to enter into reservoirs filled with viscous oils when the reservoir comprises largely unconsolidated sand grains. Injection as a liquid also may allow higher overall injection rates than injection as a gas.
[0069] In an alternative embodiment, the solvent volume is injected into the well at rates and pressures such that immediately after halting injection into the injection well at least 25 mass % of the injected solvent is in a liquid state in the underground reservoir. Injection as a vapor may be preferred in order to enable more uniform solvent distribution along a horizontal well. Depending on the pressure of the reservoir, it may be desirable to significantly heat the solvent in order to inject it as a vapor. Heating of injected vapor or liquid solvent may enhance production through mechanisms described by “Boberg, T. C. and Lantz, R. B., “Calculation of the production of a thermally stimulated well”, JPT, 1613-1623, December 1966. Towards the end of an injection cycle, a portion of the injected solvent, perhaps 25% or more, may become a liquid as pressure rises. Because no special effort is made to maintain the injection pressure at the saturation conditions of the solvent, liquefaction would occur through pressurization, not condensation. Downhole pressure gauges and/or reservoir simulation may be used to estimate the phase of the solvent and other co-injectants at downhole conditions and in the reservoir. A reservoir simulation is carried out using a reservoir simulator, a software program for mathematically modeling the phase and flow behavior of fluids in an underground reservoir. Those skilled in the art understand how to use a reservoir simulator to determine if 25% of the injectant would be in the liquid phase immediately after halting injection. Those skilled in the art may rely on measurements recorded using a downhole pressure gauge in order to increase the accuracy of a reservoir simulator. Alternatively, the downhole pressure gauge measurements may be used to directly make the determination without the use of reservoir simulation.
[0070] Although preferably a SDRP is predominantly a non-thermal process in that heat is not used principally to reduce the viscosity of the viscous oil, the use of heat is not excluded. Heating may be beneficial to improve performance, improve process start-up, or provide flow assurance during production. For start-up, low-level heating (for example, less than 100° C.) may be appropriate. Low-level heating of the solvent prior to injection may also be performed to prevent hydrate formation in tubulars and in the reservoir. Heating to higher temperatures may benefit recovery.
[0071] Table 1 outlines the operating ranges for CSDRPs of some embodiments. The present invention is not intended to be limited by such operating ranges.
[0000]
TABLE 1
Operating Ranges for a CSDRP.
Parameter
Broader Embodiment
Narrower Embodiment
Injectant volume
Fill-up estimated pattern pore
Inject, beyond a pressure
volume plus 2-15% of
threshold, 2-15% (or 3-8%) of
estimated pattern pore volume;
estimated pore volume.
or inject, beyond a pressure
threshold, for a period of time
(e.g. weeks to months); or
inject, beyond a pressure
threshold, 2-15% of estimated
pore volume.
Injectant
Main solvent (>50 mass %) C 2 -
Main solvent(>50 mass %)is
composition,
C 5 . Alternatively, wells may be
propane (C 3 ).
main
subjected to compositions
other than main solvents to
improve well pattern
performance (i.e. CO 2 flooding
of a mature operation or
altering in-situ stress of
reservoir).
Injectant
Additional injectants may
Only diluent, and only when
composition,
include CO 2 (up to about 30%),
needed to achieve adequate
additive
C 3+ , viscosifiers (e.g. diesel,
injection pressure.
viscous oil, bitumen, diluent),
ketones, alcohols, sulphur
dioxide, hydrate inhibitors, and
steam.
Injectant phase &
Solvent injected such that at
Solvent injected as a liquid, and
Injection pressure
the end of injection, greater
most solvent injected just under
than 25% by mass of the
fracture pressure and above
solvent exists as a liquid in the
dilation pressure,
reservoir, with no constraint as
Pfracture > Pinjection > Pdilation >
to whether most solvent is
PvaporP.
injected above or below
dilation pressure or fracture
pressure.
Injectant
Enough heat to prevent
Enough heat to prevent hydrates
temperature
hydrates and locally enhance
with a safety margin,
wellbore inflow consistent with
Thydrate + 5° C. to
Boberg-Lantz mode
Thydrate + 50° C.
Injection rate
0.1 to 10 m 3 /day per meter of
0.2 to 2 m 3 /day per meter of
completed well length (rate
completed well length (rate
expressed as volumes of liquid
expressed as volumes of liquid
solvent at reservoir conditions).
solvent at reservoir conditions).
Rates may also be designed to
allow for limited or controlled
fracture extent, at fracture
pressure or desired solvent
conformance depending on
reservoir properties.
Threshold
Any pressure above initial
A pressure between 90% and
pressure
reservoir pressure.
100% of fracture pressure.
(pressure at which
solvent continues
to be injected for
either a period of
time or in a volume
amount)
Well length
As long of a horizontal well as
500 m-1500 m (commercial well).
can practically be drilled; or the
entire pay thickness for vertical
wells.
Well
Horizontal wells parallel to
Horizontal wells parallel to each
configuration
each other, separated by some
other, separated by some regular
regular spacing of 60-600 m;
spacing of 60-320 m.
Also vertical wells, high angle
slant wells & multi-lateral wells.
Also infill injection and/or
production wells (of any type
above) targeting bypassed
hydrocarbon from surveillance
of pattern performance.
Well orientation
Orientated in any direction.
Horizontal wells orientated
perpendicular to (or with less than
30 degrees of variation) the
direction of maximum horizontal
in-situ stress.
Minimum
Generally, the range of the
A low pressure below the vapor
producing
MPP should be, on the low
pressure of the main solvent,
pressure (MPP)
end, a pressure significantly
ensuring vaporization, or, in the
below the vapor pressure,
limited vaporization scheme, a
ensuring vaporization; and, on
high pressure above the vapor
the high-end, a high pressure
pressure. At 500 m depth with pure
near the native reservoir
propane, 0.5 MPa (low)-1.5 MPa
pressure. For example,
(high), values that bound the
perhaps 0.1 MPa-5 MPa,
800 kPa vapor pressure of
depending on depth and mode
propane.
of operation (all-liquid or limited
vaporization).
Oil rate
Switch to injection when rate
Switch when the instantaneous oil
equals 2 to 50% of the max
rate declines below the calendar
rate obtained during the cycle;
day oil rate (CDOR) (e.g. total
Alternatively, switch when
oil/total cycle length). Likely most
absolute rate equals a pre-set
economically optimal when the oil
value. Alternatively, well is
rate is at about 0.8 × CDOR.
unable to sustain hydrocarbon
Alternatively, switch to injection
flow (continuous or
when rate equals 20-40% of the
intermittent) by primary
max rate obtained during the
production against back-
cycle.
pressure of gathering system
or well is “pumped off” unable
to sustain flow from artificial lift.
Alternatively, well is out of sync
with adjacent well cycles.
Gas rate
Switch to injection when gas
Switch to injection when gas rate
rate exceeds the capacity of
exceeds the capacity of the
the pumping or gas venting
pumping or gas venting system.
system. Well is unable to
During production, an optimal
sustain hydrocarbon flow
strategy is one that limits gas
(continuous or intermittent) by
production and maximizes liquid
primary production against
from a horizontal well.
backpressure of gathering
system with/or without
compression facilities.
Oil to Solvent
Begin another cycle if the
Begin another cycle if the OISR of
Ratio
OISR of the just completed
the just completed cycle is above
cycle is above 0.15 or
0.3.
economic threshold.
Abandonment
Atmospheric or a value at
For propane and a depth of 500 m,
pressure
which all of the solvent is
about 340 kPa, the likely lowest
(pressure at
vaporized.
obtainable bottomhole pressure at
which well is
the operating depth and well
produced after
below the value at which all of the
CSDRP cycles
propane is vaporized.
are completed)
[0072] In Table 1, embodiments may be formed by combining two or more parameters and, for brevity and clarity, each of these combinations will not be individually listed.
[0073] In the context of this specification, diluent means a liquid compound that can be used to dilute the solvent and can be used to manipulate the viscosity of any resulting solvent-bitumen mixture. By such manipulation of the viscosity of the solvent-bitumen (and diluent) mixture, the invasion, mobility, and distribution of solvent in the reservoir can be controlled so as to increase viscous oil production.
[0074] The diluent is typically a viscous hydrocarbon liquid, especially a C 4 to C 20 hydrocarbon, or mixture thereof, is commonly locally produced and is typically used to thin bitumen to pipeline specifications. Pentane, hexane, and heptane are commonly components of such diluents. Bitumen itself can be used to modify the viscosity of the injected fluid, often in conjunction with ethane solvent.
[0075] In certain embodiments, the diluent may have an average initial boiling point close to the boiling point of pentane (36° C.) or hexane (69° C.) though the average boiling point (defined further below) may change with reuse as the mix changes (some of the solvent originating among the recovered viscous oil fractions). Preferably, more than 50% by weight of the diluent has an average boiling point lower than the boiling point of decane (174° C.). More preferably, more than 75% by weight, especially more than 80% by weight, and particularly more than 90% by weight of the diluent, has an average boiling point between the boiling point of pentane and the boiling point of decane. In further preferred embodiments, the diluent has an average boiling point close to the boiling point of hexane (69° C.) or heptane (98° C.), or even water (100° C.).
[0076] In additional embodiments, more than 50% by weight of the diluent (particularly more than 75% or 80% by weight and especially more than 90% by weight) has a boiling point between the boiling points of pentane and decane. In other embodiments, more than 50% by weight of the diluent has a boiling point between the boiling points of hexane (69° C.) and nonane (151° C.), particularly between the boiling points of heptane (98° C.) and octane (126° C.).
[0077] By average boiling point of the diluent, we mean the boiling point of the diluent remaining after half (by weight) of a starting amount of diluent has been boiled off as defined by ASTM D 2887 (1997), for example. The average boiling point can be determined by gas chromatographic methods or more tediously by distillation. Boiling points are defined as the boiling points at atmospheric pressure.
[0078] In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments of the invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the invention.
[0079] Embodiments of the invention can be represented as a software product stored in a machine-readable medium (also referred to as a computer-readable medium, a processor-readable medium, or a computer usable medium having a computer-readable program code embodied therein). The machine-readable medium can be any suitable tangible medium that may be processed by a computer to perform the steps developed in this invention, including magnetic, optical, or electrical storage medium including a diskette, compact disk read only memory (CD-ROM), memory device (volatile or non-volatile), or similar storage mechanism. The machine-readable medium can contain various sets of instructions, code sequences, configuration information, or other data, which, when executed, cause a processor to perform steps in a method according to an embodiment of the invention. Those of ordinary skill in the art will appreciate that other instructions and operations necessary to implement the described invention can also be stored on the machine-readable medium. Software running from the machine-readable medium can interface with circuitry to perform the described tasks.
[0080] The above-described embodiments of the invention are intended to be examples only. Alterations, modifications and variations can 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. | Solvent-dominated hydrocarbon recovery processes use chemical solvent(s), rather than a heat-transfer agent, as the principal means to achieve hydrocarbon viscosity reduction. Such processes are fundamentally different from thermally-dominated recovery processes and have unique challenges. Field measurements described herein, such as the rate of solvent production, can be used to manage solvent-dominated hydrocarbon recovery processes, for instance for improving hydrocarbon recovery or solvent efficiency. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part application and hereby claims priority from U.S. patent application Ser. No. 10/398,348 filed on Apr. 4, 2003 now pending, the disclosure of which is hereby incorporated herein by reference in its entirety. The '348 application is a §371 application and claims priority from International Application PCT/AT01/00258 filed on Jul. 26, 2001, wherein that international application claims priority from Austrian Patent No. AT1757/2000 filed on Oct. 13, 2000, wherein the disclosures of the international application and the Austrian patent application are hereby incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] Chlorine is currently used especially for cleaning and disinfection. Compounds of chlorine such as hypochlorous acid (HOCl) or hydrochloric acid (HCl) are formed in a hydrous solution, on which in the end, together with the produced oxygen, the strongly oxidizing and therefore disinfecting effect of hydrous chlorine solutions is based. A similarly disinfecting effect is produced by the chloramines which arise during the reaction of chlorine with nitrogenous compounds, but which are felt by a number of people as being odorous and irritating to the eye. Critical side products of the disinfection with chlorine are finally chlorinated hydrocarbons. They occur in the reaction of chlorine with organic material and can be hazardous in higher concentrations. Efforts have therefore been undertaken regularly to replace chlorine by other chemicals for cleaning and disinfection without achieving the germicidal speed of chlorine.
[0003] A further problem in the use of chlorine for cleaning and disinfection is transport and storage, because special care must be observed in respective of this highly reactive substance.
[0004] Non-chlorine based detergents have been used in the past. For example, Great Britain patent GB 1 510 452 A discloses a detergent for toilet basins which consists of potassium permanganate and a sodium alkyl sulfate for reducing the surface tension. No further oxidants, especially in co-operation with potassium permanganate, are provided. The suitability of the agent must be doubted in general because no measures are undertaken in order to ensure the alkaline environment. Alkaline conditions, however, are necessary for preventing the precipitation of the manganese dioxide (Mn IV “brownstone”) which shows a low water-solubility. Moreover, these alkaline conditions promote the germicidal effect of the potassium permanganate.
SUMMARY
[0005] One benefit of this invention is to provide a detergent and disinfectant which avoids such disadvantages while maintaining a similar oxidizing and disinfecting effect.
[0006] This is achieved by providing a detergent and disinfectant comprising: water-soluble permanganate, which is provided for initiating the oxidation of organic substances, an agent for securing an alkaline environment with a pH value of at least 10, and at least one further oxidant whose oxidation potential lies over that of manganese VII to manganese VI.
[0007] The water soluble permanganate can be in the form of potassium permanganate. Potassium permanganate (KMnO 4 ) is a strong oxidant whose germicidal effect has been known for a long time. In the strongly alkaline environment, it is based in particular on the reduction of the heptavalent manganese to the oxidation number +6. For different reasons, however, the use in detergents and disinfectants was never achieved. Due to its strong oxidation effect, potassium permanganate proved to be incompatible with other necessary ingredients of a detergent for example. Furthermore, water acts as a reductive in the face of the high oxidation potential of potassium permanganate, thus leading to stability problems of the detergents in a hydrous solution.
BRIEF DESCRIPTION OF THE DRAWING
[0008] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.
[0009] In the drawings, wherein similar reference characters denote similar elements throughout the several views:
[0010] FIG. 1 is a Pourbaix diagram for showing the reactions which are relevant for the efficiency of the detergent and disinfectant according to the invention.
DETAILED DESCRIPTION
[0011] At least one embodiment of the invention relates to a detergent or disinfectant which includes water-soluble permanganate, which is provided for initiating the oxidation of organic substances, an agent for securing an alkaline environment with a pH value of at least 10, and at least one further oxidant whose oxidation potential lies over that of manganese VII to manganese VI. The above detergent or disinfectant can be formed in multiple different or varying further embodiments.
[0012] For example, in at least one embodiment, an oxidant is added to the permanganate whose oxidation potential exceeds that of the permanganate. In accordance with at least one embodiment, this is achieved by adding peroxodisulfates, preferably sodium peroxodisulfate. As will be explained below in closer detail, radical reactions are initiated by their co-operation, as a result of which there is an efficient oxidation of organic substances.
[0013] At least one embodiment relates to a detergent and disinfectant which includes peroxodisulfates, preferably sodium peroxodisulfate, which are used as a further oxidant.
[0014] At least one embodiment relates to a detergent and disinfectant, wherein potassium permanganate is used as permanganate.
[0015] At least one embodiment relates to a detergent and disinfectant, wherein alkali hydroxides are used for achieving the alkaline environment. This induces an increase in the germicidal speed of the permanganate because the oxidation of organic compounds is accelerated under alkaline conditions.
[0016] At least one embodiment relates to a detergent and disinfectant, wherein oxidation-resistant polyphosphates are used as hardness stabilizers. This ensures that the applied hardness stabilizers (complexing agents) are resistant to the peroxodisulfates. Moreover, a certain protective effect against the corrosion of non-ferrous metals and plastics can be assumed.
[0017] At least one embodiment relates to a detergent and disinfectant, wherein all components are present in powder form.
[0018] At least one embodiment relates to a detergent and disinfectant, wherein 7 to 8 grams of the detergent and disinfectant are dissolved per liter of solution of detergent or disinfectant.
[0019] At least one embodiment relates to a detergent and disinfectant, wherein it is used in the following composition:
[0020] 20%-35% of 50% KOH,
[0021] 5%-25% of 50% potassium tripolyphosphate,
[0022] 25%-35% of hypochlorite lye,
[0023] at least 0.01% KMnO 4
[0024] At least one embodiment relates to a detergent and disinfectant, wherein, it is used in a 3% hydrous solution.
[0025] At least one embodiment relates to a detergent and disinfectant comprising: water-soluble permanganate, which is provided for initiating the oxidation of organic substances, an agent for securing an alkaline environment with a pH value of at least 10, and at least one further oxidant whose oxidation potential exceeds 1.5 volts at said minimum pH of 10.
[0026] At least one embodiment relates to a detergent and disinfectant, wherein it is used in the following composition:
[0027] 58% NaOH,
[0028] 27% potassium tripolyphosphate,
[0029] 15% Na 2 S 2 O 8 ,
[0030] at least 0.01% KMnO 4
[0031] At least one embodiment relates to a detergent and disinfectant, wherein it is used in the following composition:
[0032] 28% of 50% KOH,
[0033] 15% of 50% potassium tripolyphosphate,
[0034] 30% of hypochlorite lye,
[0035] at least 0.01% KMnO 4
[0036] At least one embodiment further comprises a detergent and disinfectant, wherein said agent comprises an agent for securing an alkaline environment with a pH value of at least 12.
[0037] At least one embodiment relates to a detergent and disinfectant composition comprising:
[0038] 50%-75% NaOH,
[0039] 15%-35% of 54% potassium tripolyphosphate,
[0040] 1%-20% Na 2 S 2 O 8 , and
[0041] 0.01%-0.5% KMnO 4
[0042] At least one embodiment relates to a detergent and disinfectant comprising:
[0043] water-soluble permanganate, which is provided for initiating the oxidation of organic substances;
[0044] an agent for securing an alkaline environment with a pH value of at least 10;
[0045] at least one further oxidant in the form of a peroxodisulfate whose oxidation potential lies over that of manganese VII to manganese VI.
[0046] At least one embodiment relates to a detergent and disinfectant, wherein the at least one further oxidant has an oxidation potential that lies over that of HO 2 − to OH − .
[0047] At least one embodiment relates to a detergent and disinfectant, wherein the alkali hydroxides comprise NaOH.
[0048] At least one embodiment relates to a detergent and disinfectant, wherein the oxidation-resistant polyphosphates which are used as hardness stabilizers include potassium tripolyphosphate.
[0049] At least one embodiment relates to a detergent and disinfectant comprising:
[0050] a) a cleaning agent in the form of a water-soluble permanganate for initiating the oxidation of organic substances;
[0051] b) an alkali agent for providing an alkaline environment with a pH value of at least 10; and
[0052] c), at least one further oxidant acting as an accelerant whose oxidation potential lies over that of manganese VII to manganese VI.
[0053] At least one embodiment relates to a method for treating a beverage distribution system comprising using detergent and disinfectant comprising:
[0054] water-soluble permanganate, which is provided for initiating the oxidation of organic substances;
[0055] an agent for securing an alkaline environment with a pH value of at least 10, and which is used in combination with at least one further oxidant whose oxidation potential lies over that of manganese VII to manganese VI.
[0056] At least one embodiment relates to a detergent and disinfectant composition comprising:
[0057] 62.935% NaOH,
[0058] 30.5% of 54% potassium tripolyphosphate,
[0059] 6.4% Na 2 S 2 O 8 , and
[0060] 0.165% KMnO 4
[0061] The reactions which are relevant for the efficiency of the detergent and disinfectant according to at least one embodiment are now described in detail by reference to a Pourbaix diagram ( FIG. 1 ; for 25° C., 1 bar of atmospheric pressure and an electrolyte activity of 1 mol/L).
[0062] At first, a strong oxidant is provided in the form and concentration in accordance with at least one embodiment, which can contain an alkali peroxodisulfate. Although the alkali peroxodisulfate is a strong oxidant, is reacts only slowly with organic compounds at room temperature and under the absence of respective catalysts. The efficient and complete oxidation of organic substances is rather initiated by the potassium permanganate. Organic carbon is oxidized into oxalate. For the purpose of accelerating the reaction kinetics between potassium permanganate and organic substances, an alkali hydroxide is added, preferably NaOH, in order to thus guarantee an alkaline environment.
[0063] In the application of at least one embodiment, the detergent and disinfectant which is present in powder form is dissolved at first quickly in water without any residues. As a result of the composition, notice is taken that the dissolution of the hardness stabilizer occurs rapidly enough in order to prevent the precipitation of alkaline-earth carbonates and hydroxides as a result of the rising alkalinity of the solution, which is particularly decisive in the case of high water hardness. During the dissolution of the powder in accordance with at least one embodiment in water, there is at first the oxidation of hydroxide ions, namely by the peroxodisulfate (eq. 1) on the one hand, and also by the permanganate (eq. 2) on the other hand, with heptavalent manganese being reduced to manganese with oxidation number +6. A release of oxygen also occurs.
[0000] 3OH − +S 2 O 8 2− =HO 2 − +2SO 4 2− +H 2 O Eq. 1
[0000] 4 OH − +4MnO 4 − =O 2 ↑+4MnO 4 2− +2H 2 O Eq. 2
[0064] The hydrogen peroxide ion arising during the oxidation of hydroxide ions by the peroxodisulfate can produce a reoxidation of the Mn(VI) to Mn(VII) (eq. 3):
[0000] HO 2 − +2MnO 4 2− +H 2 O=3OH − +2MnO 4 − Eq. 3
[0065] When the decomposition rate of the peroxodisulfate cannot keep up with that of the permanganate (e.g. because the decomposition of the permanganate is promoted by a high concentration and/or favorable oxidizability of the organic substance), an increased formation of Mn(VI) will occur. The dominance of the hexavalent manganese species leads to a green coloration of the solution, which is in contrast to the initial purple coloration produced by manganese VII. The oxidation of organic compounds (designated here with “CH 2 O”, which stands generally for carbon of oxidation number 0 and in particular for carbohydrate) into oxalate by Mn VII and the thus concomitant decomposition of the permanganate occurs rapidly, because the high pH value acts in an anionizing manner on numerous organic materials, which facilitates the attack of anionic oxidants. The oxidation of organic substances by Mn VII also involves MnO 4 3− , where manganese is present with the oxidation number +5 (eq. 4), but is oxidized again into hexavalent manganese by permanganate (eq. 5).
[0000] 2{CH 2 O}+3MnO 4 + +2H 2 O=C 2 O 4 2− +3MnO 4 3− +8H + Eq. 4
[0000] MnO 4 3− +MnO 4 − =2MnO 4 2− Eq. 5
[0066] The attack of the permanganate on organic substances according to eq. 4 does not lead to the high efficiency of the powder. The rapid and efficient oxidation of organic substances is rather produced by the now starting radical reactions. The starting point is an SO 4 − radical which arises from the peroxodisulfate. This radical can be produced at first by homolytic cleavage of the peroxodisulfate (eq. 6) or by its reaction with organic compounds (eq. 7):
[0000] S 2 O 8 2− =2SO 4 − Eq. 6
[0000] 2S 2 O 3 2− +2{CH 2 O}+2H 2 O=2SO 4 2− +2SO 4 − +{C +1 —R}+4H+ Eq. 7
[0067] In equation 7, {C +1 —R} designates a radical with carbon in the oxidation number +1, e.g. formally {H 2 C 2 O 3 } 2− , in which there is a double bond between the carbon atoms. Compounds in bold print designate radicals or radical ions.
[0068] As is shown by examination results, the SO 4 + seems to be produced primarily by the co-operation with existing manganese compounds. It may be assumed that manganese VI or manganese V compounds have a radical-forming effect on peroxodisulfate according to the reactions 8 and 9:
[0000] MnO 4 2− +C 2 O 4 2− +2H 2 O=MnO 4 3− +2CO 3 2− 4H + Eq. 8
[0000] MnO 4 3− +S 2 O 8 2− =MnO 4 2− +SO 4 2− +SO 4 − Eq. 9
[0069] A cascade of radical reactions is initiated, of which only the most important will be mentioned below. Thus, the SO 4 − radical produces the formation of OH radicals (eq. 10). This radical belongs, as is generally known, to the most reactive compounds and oxidizes organic substances (eq. 11). SO 4 − radicals can subsequently be produced again (eq. 12):
[0000] SO 4 + H 2 O=HSO 4 − +OH Eq. 10
[0000] 2OH+2{CH 2 O}+H 2 O=2OH − +{C +1 —R}+4H + Eq. 11
[0000] {C +1 —R}+4S 2 O 8 2− +H 2 O=4SO 4 2− +4SO 4 − +C 2 O 4 2− +4H + Eq. 12
[0070] After its formation according to eq. 10, the hydroxide radical can also react with oxalate (eq. 13). The sulfate radical is produced again subsequently by the peroxodisulfate (eq. 14):
[0000] OH+C 2 O 4 2 =OH − +C 2 O 4 − Eq. 13
[0000] C 2 O 4 − +S 2 O 8 2− +2H 2 O=2CO 3 2− +SO 4 2− +SO 4 − +4H + Eq. 14
[0071] Another reaction channel for the oxidation of organic compounds involves the sulfate radical itself. The sulfate radical oxidizes organic compounds (eq. 15) and can finally be re-supplied again by peroxodisulfate (eq. 16):
[0000] 2SO 4 − +2{CH 2 O}+H 2 O=2SO 4 2− +{C +1 —R}+4H + Eq. 15
[0000] {C +1 —R}+4S 2 O 8 2− +H 2 O=4SO 4 2− +4SO 4 − +C 2 O 4 2− +4H + Eq. 16
[0072] The sulfate radical can also react with oxalate (eq. 17), with the same being re-supplied again by means of a peroxodisulfate molecule (eq. 18):
[0000] SO 4 − +C 2 O 4 2− =SO 4 2− +C 2 O 4 − Eq. 17
[0000] C 2 O 4 − +S 2 O 8 2− +2H 2 O=2CO 3 2− +SO 4 − +SO 4 − +4H + Eq. 18
[0073] It can thus be seen that in the course of the progress of the reactions 10 to 18 an efficient oxidation of organic compounds occurs, which oxidation is efficient through initiation of the radicals and is initiated by manganese compounds of different oxidation number and is maintained by peroxodisulfate.
[0074] Recombination reactions between radicals finally bring the chain reactions 10 to 18 to a final stop (eq. 19 to 24):
[0000] SO 4 − +SO 4 − =S 2 O 8 2− Eq. 19
[0000] SO 4 − +OH.=HSO 5 − (unstable) Eq. 20
[0000] 4SO 4 + {C + —R}+H 2 O=4SO 4 2− +C 2 O 4 2− +4H + Eq. 21
[0000] OH.+OH.=H 2 O 2 Eq. 22
[0000] 4OH.+{C +1 —R}+H 2 O=4OH − +C 2 O 4 2− +4H + Eq. 23
[0000] 3{C +1 —R}+3H 2 O=C 2 O 4 2− +4{CH 2 O}+4OH − Eq. 24
(disproportionation of e.g. {H 2 C 2 O 3 } 2− )
[0076] Since manganate (VI) acts thermodynamically unstable in water, a dominance of manganese II (eq. 25) occurs subsequently:
[0000] MnO 4 2− +H 2 O=O 2 ↑+HMnO 2 − +OH − Eq. 25
[0077] A yellow coloration of the solution shows the presence of managese(II) which forms oxalate complexes and thus also the essential completion of the cleaning and disinfection process.
[0078] During the entire progress of the chain reactions 10 to 25 there is a release of oxygen and hydrogen peroxide (eq. 1, 2, 16 and 25), which additionally supports the cleaning and disinfection process.
[0079] It is not necessary to exclusively use peroxodisulfate compounds as additional strong oxidants. Other oxidants whose oxidation potential exceeds that of manganese VII to manganese VI (line MnO 4 − /MnO 4 − in the Pourbaix diagram of FIG. 1 ), and preferably that of HO 2 − to OH − (line HO 2 − /OH − in the Pourbaix diagram of FIG. 1 ), are potential candidates. Periodate would also be suitable with respect to the line MnO 4 − /MnO 4 − , which ensures a re-oxidation of manganate V or VI into permanganate within the scope of a slightly modified chemism. Although the use of peroxodiphosphate and ozone is theoretically possible, it can hardly be realized from a technical viewpoint. Peroxodiphosphate is currently not available in larger quantities and ozone decomposes rapidly due to its high reactivity, as a result of which it does not seem to be suitable for commercial detergents and disinfectants. Although hypochlorite would be sufficiently stable in a hydrous solution, it would be necessary to ensure the electrochemical dominance of the reduction-oxidation pair ClO − /Cl − for the formation of HO 2 − ions even in the case of storage over longer periods of time.
[0080] All components of the detergent and disinfectant can be present in powdery form, a fact which apart from the efficient and rapid oxidation of organic substances is extremely advantageous for storing and transporting the agent.
[0081] Experiments also showed that the amount of sodium peroxodisulfate can be lowered, if the remaining components are adjusted suitably. This is advantageous since it helps to replace amounts of the comparably expensive peroxodisulfates by cheaper compounds. In addition, the composition of the detergent and disinfectant can be optimized for different areas of application by varying the compounds within the following ranges:
[0082] 50%-75% NaOH,
[0083] 15%-35% of 54% potassium tripolyphosphate,
[0084] 1%-20% Na 2 S 2 O 8 , and
[0085] 0.01%-0.5% KMnO 4
[0086] For use of hypochlorite lye, these ranges can be specified as follows:
[0087] 20%-35% of 50% KOH,
[0088] 5%-25% of 50% potassium tripolyphosphate,
[0089] 25%-35% of hypochlorite lye,
[0090] at least 0.01% KMnO 4
[0091] The following examples should document the versatility of the possibilities for use of the detergent and disinfectant and shall not be understood as being limiting in any way.
Example 1
[0092] The detergent and disinfectant in accordance with at least one embodiment can be used especially appropriately for beverage dispensing systems. The respective powder mixture contains 58% NaOH (prilled), 27.10% potassium tripolyphosphate, 14.75% sodium peroxodisulfate and 0.15% potassium permanganate. The application occurs in a concentration of approx. 8 g of powdery product per liter, with the dissolution in water occurring rapidly and free from residues. The release of sulfate, hydroxide and other radicals as well as the alkalinity promote the cleaning and disinfection process. The color change from purple (dominance of the manganese (VII) species) to green (dominance of the manganese (VI) species) and finally to yellow (dominance of the manganese (II/IV)) allows a visual evaluation of the cleaning progress.
Example 2
[0093] The detergent and disinfectant in accordance with at least one embodiment can also be used for cleaning bottles. Currently, soiled bottles are immersed in lye baths. These baths substantially contain NaOH and additives for reducing the surface tension and need to be heated to at least 70° C. in order to allow a cleaning process. With the detergent and disinfectant it is possible to also achieve the desired sterilization at room temperature, which reduces the required machinery and improves cost-effectiveness. The bottles are merely sprayed with a powder mixture which is dissolved in water or with the two components NaOH/potassium tripolyphosphate and peroxodisulfate/permanganate which are present in liquid form. Following an exposure time which can be optimized easily due to the change of color, the sterilized bottles are sprayed off with water.
Example 3
[0094] Inorganic coatings in vegetable- or potato-processing plants or breweries are usually difficult to dissolve because they consist of a mixture of salts which cannot be dissolved very well either by mineral acids or in alkaline solutions. They concern potassium oxalates, magnesium ammonium phosphates or silicates. The detergent and disinfectant allows the near residue-free removal of such precipitations. A hydrous solution of approx. 10% is produced with the recipe of this embodiment and the surfaces to be cleaned are treated with the same. Following an exposure time of less than one hour the coatings can be rinsed off easily with water.
Example 4
[0095] The detergent and disinfectant in accordance with one embodiment can also be used for cleaning purposes in industrial applications, in particular for cleaning piping, in the following composition: 62.935% NaOH, 30.5% potassium tripolyphosphate, 6.4% sodium peroxodisulfate and 0.165% potassium permanganate. Again, the release of sulfate, hydroxide and other radicals as well as the alkalinity promote the cleaning and disinfection process. In addition, the color change from purple (dominance of the manganese (VII) species) to green (dominance of the manganese (VI) species) and finally to yellow (dominance of the manganese (II/IV)) allows a visual evaluation of the cleaning progress.
[0096] Accordingly, while a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention as defined in the appended claims. | A detergent and disinfectant in which water-soluble permanganates are used in an alkaline solution in order to initiate the oxidation of organic substances and simultaneously a chemical oxidant, preferably a peroxodisulfate, is used which is capable of producing radical reactions with catalytic support by manganates originating from the supplied permanganate, which reactions produce the oxidation of organic substances. All components are present in powder form and a respective powder mixture can be dissolved rapidly and free from residues in water. It thus represents a universally applicable, highly effective detergent and disinfectant. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. Ser. No. 10/677,496 filed on Oct. 3, 2003, now U.S. Pat. No. 7,018,813 which is a divisional of U.S. Ser. No. 09/825,770 filed on Apr. 4, 2001, which issued as U.S. Pat. No. 6,686,180, which claims priority to Provisional Application No. 60/194,482 filed on Apr. 4, 2000. The entire contents of each of the above-identified applications are hereby incorporated by reference.
REFERENCE TO SEQUENCE LISTING, TABLES OR COMPUTER PROGRAM LISTING
A Sequence Listing in computer readable format is included herewith.
BACKGROUND OF THE INVENTION
The present invention relates to increasing bacterial toxin production using methods and compositions that reduce, or eliminate, the accumulation of intracellular and extracellular toxin expression inhibitors. Specifically, the present invention related to methods and compositions for reducing or elimination the accumulation of Bordetella species toxin expression inhibitors. More specifically, the present invention relates to the high yield production of pertussis toxin, pertactin, adenylate cyclase toxin-hemolysin, filamentous hemagglutinin and other toxins.
Pertussis toxin (PT) is one of the various components produced by virulent B. pertussis , the microorganism that causes whooping cough. Whooping cough is a serious infection of the respiratory system that at one time was responsible for the death of 5,000 to 10,000 people in the United States each year. Since the advent of the whooping cough vaccine the number of whooping cough related deaths has been reduced to less than 20 annually. Currently, about 50% of all whooping cough infections occur in children less than 1 year old, and only 15% occur in children over than 15 years old.
PT is a major protective antigen in the vaccine against whooping cough. Other components of interest produced by B. pertussis are filamentous hemagglutinin, heat labile toxin, adenylate cyclase and the like, which may also play important role as protective antigens. Large-scale production of these components, which are useful as diagnostic or chemical reagents and in the preparation of vaccines, requires large-scale cultivation of the microorganism. However, B. pertussis is a fastidious organism that has proved difficult to grow in large fermentors. Older methods for the culture of B. pertussis employ cultivation in stationary culture or in fermentors. Growth in a stationary culture is labor intensive, while cultivation on a fermentation scale requires vortex stirring and surface aeration. As a result, the effective volume of the fermentor is reduced and modification of the fermentor for growth of pertussis is often necessary. Furthermore, the quantities of PT produced during fermentation under these conditions are variable and often low.
U.S. Pat. No. 5,338,670 discloses a method for the production of B. pertussis in the presence of an iron salt, namely ferrous sulfate. While high iron content supports greater bacterial growth, it suppresses the production of PT. By adjusting the iron content of modified Stainer-Scholte media to 10% of the recommended concentration, the production of PT was optimized.
The present invention seeks to improve the yield of PT obtained from B. Pertussis by (1) introducing a soluble salt into the growth medium that sequesters sulfate (SO 4 2− ) and/or (2) employing a B. pertussis cysteine desulfinase knockout mutant.
BRIEF SUMMARY OF THE INVENTION
The present invention is based upon the discovery that bacterial toxin expression inhibitors accumulate in culture media and thus significantly reduce toxin production. Moreover, the present invention is based on the findings that suppressing or eliminating toxin expression inhibitors can significantly up regulate toxin expression. Non-limiting examples of the present invention are disclosed using Bordetella sp., specifically, B. pertussis and/or B. bronchiseptica which produce pertussis toxin (PT) and pertactin respectively. However, it is understood, that higher bacterial toxin levels can be achieved in other bacterial culture systems using the teachings of the present invention including but not limited to adenylate cyclase toxin-hemolysin, and filamentous hemagglutinin.
Generally, the present invention is exemplified by disclosing methods and compositions used to cultivate B. pertussis that eliminate, or reduce, intracellular and extracellular PT inhibitor accumulation resulting in significant PT production increases.
In one embodiment of the present invention methods and compositions for preparing novel culture media that support B. pertussis growth and prevent or decrease PT inhibition expression by sulfate anions are disclosed. These media compositions and related methods include, but are not limited to, admixing a B. pertussis culture medium with an effective amount of one or more soluble metal salts that form substantially insoluble complexes with sulfate anions.
In another embodiment of the present invention culture media that support B. pertussis growth comprising an amount of one or more soluble salts that form substantially insoluble complexes with PT inhibitors, wherein said amount prevents or reduces the inhibition of PT expression are provided. Specifically, soluble metal salts are disclosed that from substantially insoluble complexes with sulfate anions.
Other embodiments of the present invention include B. pertussis culture media and methods for making and using same that reduce PT inhibitors by limiting or eliminating media constituents that contribute to PT inhibitor accumulation. Specifically, in one embodiment of the present invention cysteine concentration is reduced.
The invention also relates to methods and compositions for producing PT comprising cultivating B. pertussis under conditions that eliminate, or reduce, the accumulation of PT inhibitors in the culture media resulting in significant PT production increases and isolating the PT from the culture medium.
In yet another embodiment of the present invention PT production is enhanced using B. pertussis cysteine desulfinase knockout mutants. In one embodiment of the present invention methods of producing PT comprising growing a B. pertussis cysteine desulfinase knockout mutant in a B. pertussis culture medium, and isolating the PT from the culture medium are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 : Graph showing the growth of B. pertussis (OD 650) as well as changes in the amounts of PT ([Ptx]/OD) produced as a function of fermentation time.
FIG. 2 : Picture of a blood agar plate.
FIG. 3 : Bar graph showing growth of B. pertussis (OD 650) and amount of PT (Ptx Conc.) in control culture supernatant (Ctr.), culture medium containing molecules <3,000 KDa (<3K) from spent culture media, and culture medium containing molecules >3,000 KDa (>3K) from spent culture media.
FIG. 4A : Graph of fermentation time (hours) vs. aspartic acid, threonine cysteine and lysine concentration (mg/L) and arginine, methionine and proline concentration (mg/L) demonstrating the amino acid profiles during fermentation.
FIG. 4B : Graph of time (hours) vs. area (mAU□sec) demonstrating changes in the organic acid concentrations as a function of fermentation time.
FIG. 5 : Bar graph showing sulfate concentration (μg/mL) at various culture times.
FIG. 6 : Graph demonstrating the effect of increasing concentrations of BaCl 2 (mM) on the amount of PT produced (μg/ml/OD 650 ) for two B. pertussis strains (strain 1=CS-87, strain 2=ATCC 9797).
FIG. 7A , FIG. 7B and FIG. 7C : Depict a comparison of the DNA sequence and translated amino acid sequence of the cysteine desulfinase gene isolated from B. pertussis strain BP536 (SEQ ID NO: 7) with the B. pertussis sequence (SEQ ID NO: 6) (contig 314) found in The Sanger Centre DNA data base. The DNA have been assigned (SEQ ID NOS: 8-12), respectively, in order of appearance.
FIG. 8 a : Graphically depicts total B pertussis toxin production in 20 liter fermentors under limiting cysteine conditions measure at 600 nm absorbance.
FIG. 8 b : Graphically depicts B pertussis toxin production in 20 liter fermentors under limiting cysteine conditions measured as mg/mL of toxin per optical density unit.
FIG. 9 : Graphically depicts internal and external sulfate concentrations in B. pertussis cells in 20 liter fermentors in limiting cysteine conditions.
DETAILED DESCRIPTION OF THE INVENTION
The most serious consequences of bacterial infections often result from toxin expression in the host. Non-limiting examples include, Clostridium tetani which produces tetanus toxin, neurotoxins produced by C. botulinum, C. difficile which produces toxins that cause pseudomembranous colitis, Salmonella typhi produces enterotoxins that cause gastroenteritis and typhoid fever, Staphylococcus aureus can express toxins that cause septic shock and B. pertussis produces toxins responsible for whooping cough. Other toxogenic genera of bacteria include, but are not limited to, Escherichia, Shigella , and Vibrio . Fortunately, vaccines are available that prevent and/or palliate the most severe effects of bacterial toxins. These vaccines are primarily composed of modified bacterial toxins, sub-lethal doses of purified toxin and or/or whole cell homogenates.
Bordetella pertussis vaccines have proven particularly effective in preventing whooping cough in vaccine recipients. Acellular pertussis (AP) vaccines containing Pertussis toxin (PT) alone or in combination with other antigens of B. pertussis have been found to be very effective in the prevention of pertussis infections. However, because PT and many of the other pertussis antigens are expressed in minute quantities, it is important to optimize culture conditions to maximize yields. Using the standard Stainer-Scholte (SS) media, a reduction in the pertussis toxin/optical density (PT/OD 650 ) ratio midway through batch fermentations was observed. To determine whether this phenomenon was due to a lack of substrate availability or negative feedback inhibition, studies were conducted to determine whether spent media contained inhibitory factors for PT expression and to identify these factors. Culture supernatant samples were take from various stages of fermentation and re-supplied with SS media components lacking the basic salts. These samples were used to initiate a second culture and PT/OD 650 ratios measured as compared to fresh SS media. Both intact spent media and a fraction of this media containing molecules <3,000 kDa inhibited the production of PT. Cross-streaking experiments on Bordet-Gengou Agar (BGA) confirmed the production of inhibitor(s) of hemolytic activity in freshly streaked bacteria. Coomassie stained gels showed that the whole cell protein profiles were significantly different in the fraction media compared to fresh media suggesting that the inhibitory factors were influencing the two component regulatory system. To further identify these inhibitory compound(s), a complete flux analysis of the intermediate metabolism of B. pertussis was performed including amino acid and organic acid analysis by HPLC of the spent media as well as crucial enzymes within these pathways. The sulfur-containing amino acid, methionine, and pyruvate, were found to accumulate during late exponential phase of growth (up to 200 mg/L). Examination of all supernatant fractions by LC-MS suggests that pathways for cysteine consumption lead to the formation of sulfate. This in turn acted as a negative feedback inhibitor of PT expression.
Since sulfate acts as an inhibitor of PT expression in B. pertussis , methods were developed for reducing or eliminating intracellular and extracellular sulfate accumulation as the fermentation proceeds. In one embodiment of the present invention these methods include the addition of an effective amount of a soluble salt that forms a substantially insoluble complex with sulfate. Such soluble salts include alkali earth metal salts or other salts of Pb and Ag. Preferred salts of the present invention are alkali earth metal salts. More preferred salts are Ba(II) halide salts. The most preferred Ba(II) halide salt is BaCl 2 or BaBr 2 .
Barium chloride has been shown to be effective in promoting an increase in the amount of PT produced by B. pertussis . A ten-fold increase per OD unit in the yield of PT was observed when the ATCC 9797 or CS87 B. pertussis strain was cultivated in the presence of BaCl 2 . In this case, the amount of PT in the absence of BaCl 2 was 0.05 μg/mL/OD 650 as compared to 0.525 μg/mL/OD 650 with 20 mM BaCl 2 . By “effective amount” of a salt is meant an amount that prevents or reduces inhibition of PT expression by sulfate during fermentation compared to when the fermentation is performed in the absence of the salt.
The solubility of the sulfate complex is defined by the solubility product (K sp ). The sulfate complex is defined as “substantially insoluble” when the K sp is approximately 1×10 −5 or less at 25° C. Preferably, the K sp is from about 1×10 −7 to about 1×10 −10 at 25° C. Most preferably the K sp is from about 1×10 −8 to about 1×10 −10 at 25° C. Solubility products that fall within the aforementioned ranges for selected sulfate complexes are shown in Table 1.
TABLE 1
K sp Values for Selected Sulfate Complexes
Complex
K sp (at 25° C.) a
BaSO 4
1.05 × 10 −10
PbSO 4
1.82 × 10 −8
SrSO 4
3.42 × 10 −7
AgSO 4
1.19 × 10 −5
a CRC Handbook of Chemistry and Physics-65 th Ed., Weast (ed.), p. B-220 (1984).
The sulfate complexes shown in Table 1 are meant to be examples and, as such, are not meant to narrow the scope of the present invention. In addition, it should be noted that the sulfate complex need not be completely insoluble in the growth medium. The sulfate complex must simply be sufficiently insoluble to prevent or reduce inhibition of PT expression by sulfate.
The salts of the present invention may be added to the medium before or after the cultivation of B. pertussis is initiated. Alternatively, the salt may be admixed with the other components of the medium prior to or after the addition of the water used in the preparation of the medium, but before the introduction of the B. pertussis cells.
An amount of the salt that may be used in the present invention to promote an increase in the amount of PT produced during fermentation may be from about 0.05 mM to about 50 mM, more preferably, from about 10 mM to about 30 mM, most preferably, about 20 mM. Normally from about 10 mM to about 20 mM of the salt is effective to prevent or reduce inhibition of PT expression by sulfate. One of ordinary skill in the art can determine the optimal amount of salt that effectively prevents or reduces inhibition of PT expression in any particular B. pertussis strain with no more than routine experimentation.
In another embodiment the present inventors have determined that regulating media concentrations of toxin inhibitor precursors can reduce both intracellular and extracellular toxin inhibitor concentrations. For example, and not intended as a limitation, the present inventors have determined that the PT inhibitors including, but not limited to, sulfites and sulfates are produced as end products of cysteine metabolism. Briefly, Bordetella metabolizes the sulfur containing amino acid cysteine via a pathway involving the enzyme cysteine desulfinase. During cysteine metabolism, a sulfhyral group is enzymatically cleaved from the cysteine molecule. This sulfhyral group is further metabolized into sulfites and sulfates that accumulate within the bacterial cell and the extracellular milieu. Consequently, the longer Bordetella is grown in the presence of cysteine, the higher the intracellular and extracellular sulfate concentrations become and the less PT produced.
Based on the relationship between initial culture media cysteine concentrations and final sulfate concentrations, the present inventors developed the non-limiting theory that reducing the initial cysteine concentrations would result in reduced intracellular and extracellular sulfate accumulation and consequently, reduced PT inhibition. To evaluate the effect that varying cysteine concentrations have on sulfate concentration, the present inventors developed a three different culture systems identified using the following abbreviations: LCMSSB, LCMSSFB and LCMSSBa. The LCMSSB (limiting cysteine modified Stainer-Scholte batch) culture system consisted of B. pertussis grown in batch mode using the media as shown in Table 2 below. Briefly, “batch mode” is a process whereby micro-organisms are cultured in a single culture medium, usually liquid or semi-liquid, without replenishing or exchanging a significant amount of the spent, or used, culture media. In the present invention batch mode cultures (LCMSSB) were incubated aerobically at between approximately 35° C. and 37° C. until bacterial optical densities reached >1.0 absorbance units as measured spectrophotometrically at 600 nm using procedures known to those skilled in the art. The second culture systems LCMSSFB (limiting cysteine modified Stainer-Scholte fed batch) was maintained using the culture media disclosed in Table 3. Note that no cysteine was added to the basal media. Instead, L-cysteine was added at a rate of 20 mg/hour for the entire incubation period. The final culture system was designated LCMSSBa (limiting cysteine modified Stainer-Scholte batch plus BaCl 2 ) and used the basal media depicted in Table 2.
All three culture systems were inoculated and maintained as follows: Bordetella cultures were incubated at between approximately 35° C. and 37° C. in 20 liter bioreactors (New Brunswick BioFlo IV® (New Brunswick Scientific, Edison N.J.) connected to an AFS Biocommand v2.0 (New Brunswick Scientific, Edison N.J.) which collected data for pH, agitation, dissolved oxygen, temperature, and air flow rate. Additional pumps for anti-foam agents and pH control reagents were added as needed as known to those of ordinary skill in the art. Airflow was adjusted to 4.0 liters per minute, dissolved oxygen was maintained at 40% and pH was maintained at approximately 7.2.
Each 20-liter bioreactor contained 11 liters of test media and was inoculated with one liter of actively growing bacterial starter culture. The actively growing started cultures were prepared by inoculating shaker flasks containing one liter of Stainer Scholte (SS) medium, the formula of which is depicted in Tables 5 and 6, with frozen seed and incubated until an optical density of >1.0 OD 600 was reached (approximately 20-24 hours).
The inoculated fermentors were sampled at 3-6 hour intervals and separated into culture supernatants and cell pellets using centrifugation. The culture supernatants were assayed for PT, sulfates, organic acids, amino acids and bacterial density. Bacterial cell pellets were analyzed for internal sulfate and PT concentrations. Each culture system received a specific supplement(s) when culture bacterial population densities reached approximately >1.0 absorbance units (approximately 12 hours post inoculation). Both LCMSSB and LCMSSBa received 200 mL of the amino acid supplement described in Table 4 below in addition to 10.0 mg/L FeSO 4 .7H 2 O and 5.0 g/L monosodium glutamate (the FeSO 4 /glutamate supplement). The LCMSSBa culture also received sufficient 1 mM BaCl 2 to obtain a final culture media concentration of 20 nM BaCl 2 ; the LCMSSFB cultures received the FeSO 4 /glutamate supplement with additional amino acids excluding cysteine and no BaCl 2 . After supplementation, the fermentors were incubated as before until the experiments were terminated.
TABLE 2
Components of the LCMSSB Medium.
Component
Amount (g/L)
Sodium Chloride
2.5
KH 2 PO 4
0.5
KCl
0.2
MgCl 2 •6H 2 O
0.1
CaCl 2
0.02
TRIS Base
1.525
Ascorbic Acid
0.02
Glutathione
0.10
L-Cysteine Monohydrochloride
0.04
FeSO 4 •7H 2 O
0.0010
Niacin
0.004
L-Arginine Monohydrochloride
0.40
L-Asparagine
0.10
L-Aspartic Acid
0.04
L-Histidine
0.03
L-Isoleucine
0.10
L-Leucine
0.10
L-Lysine Monohydrochloride
0.08
L-Methionine
0.03
L-Phenylalanine
0.03
L-Serine
0.06
L-Threonine
0.04
L-Tryptophan
0.01
L-Valine
0.04
TABLE 3
Components of the LCMSSFB Medium.
Component
Amount (g/L)
Sodium Chloride
2.5
KH 2 PO 4
0.5
KCl
0.2
MgCl 2 •6H 2 O
0.1
CaCl 2
0.02
TRIS Base
1.525
Ascorbic Acid
0.02
Glutathione
0.10
FeSO 4 •7H 2 O
0.0010
Niacin
0.004
L-Arginine Monohydrochloride
0.40
L-Asparagine
0.10
L-Aspartic Acid
0.04
L-Histidine
0.03
L-Isoleucine
0.10
L-Leucine
0.10
L-Lysine Monohydrochloride
0.08
L-Methionine
0.03
L-Phenylalanine
0.03
L-Serine
0.06
L-Threonine
0.04
L-Tryptophan
0.01
L-Valine
0.04
TABLE 4
Components of the Amino Acid Supplement
L-Cysteine Monohydrochloride
0.05
L-Arginine Monohydrochloride
0.40
L-Asparagine
0.10
L-Aspartic Acid
0.04
L-Histidine
0.03
L-Isoleucine
0.10
L-Leucine
0.10
L-Lysine Monohydrochloride
0.08
L-Methionine
0.03
L-Phenylalanine
0.03
L-Serine
0.06
L-Threonine
0.04
L-Tryptophan
0.01
L-Valine
0.04
All three reduced cysteine culture systems (LCMSSB, LCMSSFB and LCMSSBa) were tested in parallel with conventional SS media having cysteine concentrations as known in the prior art. Bordetella bacterial and PT concentrations are graphically depicted in FIGS. 8 a and 8 b . It can be seen from FIG. 8 a that maximum Bordetella cell concentrations were reached at approximately 32 hours. Maximum growth was nearly identical when normal PT production media is compared with modified SS in batch mode. FIG. 8 b depicts maximum PT production as measure in mg/ml of culture media. It is readily apparent that a significant improvement in overall PT production is realized using any of the cysteine limiting culture systems of the present invention when compared to conventional culture systems. Moreover, FIG. 9 depicts internal and external sulfate concentrations in B. pertussis cells in 20 liter fermentors in limiting cysteine conditions. The LCMSSBa culture system demonstrated the best improvement in overall PT production. Therefore, as theorized by the present inventors, PT production can be significantly improved by limiting the amount of inhibitor precursor in the culture media. Moreover, even further improvement can be realized when the precursor limiting culture systems of the present invention are combined with the toxin expression inhibitor removal systems of the present invention.
The present inventors have demonstrated that: 1) specific toxin expression inhibitors that accumulate in the media of toxin producing bacteria can significantly reduce overall toxin production; and 2) that removal of toxin expression inhibitors from the culture media, or reduction in toxin inhibitor formation by reducing inhibitor precursors in the culture media, can significantly increase overall toxin production. Therefore, the present inventors theorized that genetically disabling a toxin producing organism's ability to produce a toxin expression inhibitor might yield similar increases in overall toxin production. Consequently, in yet another embodiment of the present invention a recombinant B. pertussis lacking cysteine desulfinase activity (“knockout mutant”) that does not produce sulfate in culture and, thus, does not exhibit inhibited PT expression is provided. Such knockout mutants may be prepared by anyone of a number of different methods. See, for example, U.S. Pat. Nos. 5,557,032 and 5,614,396. Such methods, in general, involve homologous recombination of a DNA construct with B. pertussis chromosomal DNA. Homologous recombination is a well-studied, natural cellular process which results in the scission of two nucleic acid molecules having identical or substantially similar sequences (i.e. homologous), and the ligation of the two molecules such that one region of each initially present molecule is ligated to a region of the other molecule. (See Sedivy, J. M., BioTechnol. 6:1192-1196 (1988)). Homologous recombination is, thus, a sequence specific process by which cells can transfer a “region” of DNA from one DNA molecule to another. For homologous recombination to occur between two DNA molecules, the molecules must possess a “region of homology” with respect to one another. Such a region of homology must be at least two base pairs long. Two DNA molecules possess a region of homology when one contains a region whose sequence is so similar to a region in the second molecule that homologous recombination can occur. Where a particular region is flanked by two regions of homology, then two recombination events may occur, resulting in an exchange of regions between the two recombining molecules. Homologous recombination is catalyzed by enzymes that are naturally present in B. pertussis.
In one such method, the gene coding for cysteine desulfinase ( FIG. 7 ), e.g. contained within a plasmid, is cut with restriction enzymes selected to cut within the gene such that a new DNA sequence encoding a marker gene can be inserted within the cysteine desulfinase gene sequence. This marker gene will serve to prevent expression of the cysteine desulfinase gene. The marker gene can be any nucleic acid sequence that is detectable and/or assayable, however, in a preferred embodiment, it is an antibiotic resistance gene. The marker gene may be operably linked to its own promoter or to another strong promoter from any source that will be active or easily activatable in B. pertussis . In another embodiment, the marker gene may be transcribed using the promoter of the cysteine desulfinase gene. The marker gene may have a poly A sequence attached to the 3′-end of the gene to terminate transcription. Preferred marker genes include any antibiotic resistance gene such as ermC′ (the erythromycin resistance gene), neo (the neomycin resistance gene), amp (the ampicillin resistance gene), kan (the kanamycin resistance gene) and gent (the gentamicin resistance gene).
After the DNA sequence has been digested with the appropriate restriction enzymes, e.g. SpiI and SphI or PstI and PvoI, the marker gene sequence is ligated into the cysteine desulfinase DNA sequence using methods well known to the skilled artisan and disclosed, for example, in Sambrook et al. (Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (1989)). The ends of the DNA fragments to be ligated must be compatible; this is achieved by either cutting all fragments with enzymes that generate compatible ends, or by blunting the ends prior to ligation. Blunting is done using methods well known in the art, such as for example, by use of Klenow fragment (DNA polymerase 1) or other DNA polymerase to fill in sticky ends. This construct contains DNA sequences corresponding to defined regions of the cysteine desulfinase gene, e.g. corresponding to the 3′- and 5′-ends of the cysteine desulfinase gene, allowing for integration of the construct by homologous recombination. This DNA construct may be ligated into a plasmid having a second antibiotic resistance gene.
The construct may then be transfected into B. pertussis using known methods, e.g. by electroporation or by mating with transfected E. coli cells. Screening of the cells is accomplished by culturing the cells in the presence of otherwise lethal concentrations of one or more antibiotics corresponding to the antibiotic resistance genes that are present. Those cells that survive will have the knockout construct integrated therein. One may use a non-replicating plasmid so that the selected cells would not just have the plasmid construct therein. In order to confirm the integration of the knockout construct, a Southern Blot of the B. pertussis DNA can be probed with a sequence designed to hybridize only to the marker sequence and/or the portion of the cysteine desulfinase that is removed. Alternatively or additionally, the DNA can be amplified by PCR with probes corresponding to the 3′- and 5′-ends of the cysteine desulfinase gene. Finally, cysteine desulfinase activity may be assayed.
In another embodiment, B. pertussis may be cultivated in the presence of nucleotide sequences that are anti-sense to the coding sequence of the cysteine desulfinase gene. In this embodiment, the nucleotide sequences are taken up by B. pertussis , hybridize to the cysteine desulfinase-encoding gene, and inhibit translation of the gene. Modified nucleotide sequences can also be employed which interact with the bases of the gene to form covalent bonds and thereby inhibit translation. See U.S. Pat. No. 6,015,676.
Examples of nucleotides which are antisense to the cysteine desulfinase gene include any nucleotide of at least 8 bases, preferably, 10 to 15 bases, which are complementary to the coding region of FIG. 7 . Examples include:
GATTGCTGAT (SEQ. ID. NO. 1) TAGATGGGGC (SEQ. ID. NO. 2)
In the present invention, a variety of media may be used to cultivate B. pertussis . Non-limiting, exemplary media include the Stainer Scholte and the GMAR modified media. The components of the Stainer Scholte and GMAR modified media are presented in Tables 5 and 6, respectively.
TABLE 5
Components of the Stainer Scholte Medium. b
Component
Amount (g/L)
L-Glutamic Acid Monosodium Salt
10.72
L-Proline
0.24
Sodium Chloride
2.5
KH 2 PO 4
0.5
KCl
0.2
MgCl 2 •6H 2 O
0.1
CaCl 2
0.02
TRIS Base
1.525
Ascorbic Acid
0.02
Glutathione
0.10
L-Cysteine
0.04
Nicotinic Acid
0.004
FeSO 4 •7H 2 O
0.010
b From: Hewlett and Wolff, J. Bacteriol. 127: 890–898 (1976).
TABLE 6
Components of the GMAR Modified Medium.
Component
Amount (g/L)
L-Glutamic Acid Monosodium Salt
10.7
L-Proline
0.24
Sodium Chloride
2.50
KH 2 PO 4
0.50
KCl
0.20
MgCl 2 •6H 2 O
0.10
CaCl 2 •2H 2 O
0.02
TRIS Base
1.52
Ascorbic Acid
0.02
Glutathione, Reduced
0.10
L-Cysteine
0.04
Niacin
0.004
FeSO 4 •7H 2 O
0.001
L-Arginine Monohydrochloride
0.40
L-Asparagine
0.10
L-Aspartic Acid
0.04
L-Cysteine Monohydrochloride
0.10
L-Histidine
0.03
L-Isoleucine
0.10
L-Leucine
0.10
L-Lysine Monohydrochloride
0.08
L-Methionine
0.03
L-Phenylalanine
0.03
L-Serine
0.06
L-Threonine
0.04
L-Tryptophan
0.01
L-Valine
0.04
The PT toxin produced by the methods of the current invention may be purified according to the method described by Sekura et al., J. Biol. Chem. 258:14647-14651 (1983). Briefly, the method of Sekura utilizes two consecutive chromatographic steps to purify PT. The first step involves chromatography on an Affi-gel blue column. The second step involves chromatography on a fetuin-agarose column. The PT purification method of Sekura et al. allows for the routine and rapid purification of PT in relatively large quantities (in excess of 10 mg). Alternatively, PT may be purified using a peptide affinity column. Such a column is described below in Example 1. In this embodiment, the PT is adsorbed onto the column, washed with buffer (e.g. 50 mM TRIS HCl, pH=6.2), and the PT is then eluted with 4 M MgCl 2 . The MgCl 2 is removed by dialysis to give substantially pure PT.
Having now generally described this invention, the same will be understood by reference to the following examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.
EXAMPLE 1
Materials and Methods
Organisms: Wild-type B. pertussis strain CS87 was used for most of these studies. This strain originated in China and was brought to the National Institute of Child Health and Human Development (NICHD) at the National Institutes of Health (NIH). In addition, several strains of BP were procured from the American Type Culture Collection (Manassas, Va.), including, but not limited to ATCC number 10380 both of which are suitable for preparing the cysteine desulfinase knockout mutants disclosed herein. Organisms were stored at −70° C. or maintained on BGA (BBL, Inc. Rockville, Md.) in a humid incubator maintained at 37° C.
The medium utilized to culture the cells was similar to the defined medium described by Stainer and Scholte. J. Gen. Microbiol. 63:211-220 (1970). One liter of the medium contained: 10.7 g monosodium glutamate, 0.24 g proline, 2.5 g NaCl, 0.5 g KH 2 PO 4 , 0.2 g KCl, 0.1 g MgCl 2 .6H 2 O, 20 mg CaCl 2 .2H 20 , 1.52 g Tris, 20 mg ascorbic acid, 100 mg glutathione, 40 mg cysteine, and 4 mg niacin. The salts, glutamate, and proline were prepared as a basal formulation and were autoclaved for sterilization. The rest of the medium (supplement) was prepared in concentrated form (100-fold) and filter sterilized. The final pH of the medium was between 7.2 and 7.5. In some experiments, 10 mg/L FeSO 4 .7H 2 O was added. Organisms were grown either in triple baffled Erlenmeyer flasks in a New Brunswick Innova Model 4300 shaking incubator (New Brunswick Scientific, Edison, N.J.) maintained at 37° C. or in a New Brunswick 20 L BioFlo IV (New Brunswick Scientific) running in batch mode with a working volume of 12 L. The reactor was connected to an AFS Bio Command v.2.0 (New Brunswick Scientific), which collected data for pH, agitation, dissolved oxygen, temperature, air flow rate and additional pumps for antifoam and pH maintenance. The air flow rate in the fermentor was set at 0.125 vvm and the temperature was controlled at 36.5° C. in all experiments. The dissolved oxygen (DO) was maintained at 40% by using an agitation cascade from 150 to 1000 RPM. The pH was controlled at 7.2 by the addition of 50% H 3 PO 4 .
The reactor was batched with approximately 11 L of defined medium and inoculated with an actively growing seed (1 L), for a total working volume of 12 L. Samples were drawn from the resterilization sample port every 3 to 6 hours. For analysis of extracellular metabolites, the supernatant was filtered through a 0.2 μm Millex-GV filter (Millipore Co., Bedford, Mass.) and stored at −20° C.
Growth of the culture was measured by optical density at 650 nm (OD 650 ) using a Shimadzu UV Spec 120 (Shimadzu, Columbia, Md.). Culture purity was verified by gram staining and plating on BGA (BBL, Inc. Rockville, Md.) and trypticase soy agar (TSA; BBL, Inc.). A pure culture of B. pertussis would demonstrate all organisms staining gram-negative, growth on BGA agar and lack of growth on TSA agar.
Amino acid analysis: The analysis and quantification of amino acids were made by reverse phase high-pressure liquid chromatography (RP-HPLC) using an on-line pre-column derivatization, as provided for the AminoQuant column (Hewlett-Packard Co., Wilmington, Del.). Primary acids were derivatized by the OPA reagent (10 mg/ml o-phtalaldehyde, 10 mg/ml 3-mercaptopropionic acid in 0.4 M borate buffer), while secondary amino acids were derivatized by FMOC reagent (2.5 mg/ml 9-fluorenylmethylchloroformate in acetonitrile). For primary amino acids, the mobile phase consisted of sodium acetate/tri-ethanolamine/tetrahydrofuran (pH 7.2±0.05) and were detected at 338 nm. Secondary amino acids were eluted using a sodium acetate/methanol/acetonitrile mobile phase (pH 7.2±0.05) and were detected at 262 nm. The identification of each amino acid was performed with a set of amino acid standards (Hewlett-Packard) at different concentrations (100, 250, and 1000 pmol/μl). HPLC Model HP-1050 (Hewlett-Packard) was utilized for these analyses in conjunction with the HP ChemStation software (Hewlett-Packard, v.2.0).
Organic Acid detection and quantification: Organic acids were detected using a Model HP-1050 HPLC (Hewlett-Packard) in conjunction with the HP ChemStation v.2.0 software and equipped with a BioRad Aminex HPX-87H column (Bio-Rad Laboratories, Burlingame, Calif.) having a mobile gas phase of 4 mM H 2 SO 4 . The column was equilibrated at 35° C. and the isocratic flow rate was 0.6 ml/min. The detection was performed at 215 nm. The identification of each organic acid was achieved by injecting the Bio-Rad Organic Acid Analysis Standard (Bio-Rad Laboratories), which consisted of a mixture of sodium oxalate, sodium citrate, sodium maleate, sodium succinate, sodium formate, and sodium acetate. Pyruvate was assessed by spiking the organic acid standard with 2.5 g/l pyruvate.
Each of the organic acids were quantified using enzymatic kits and following the manufacturer's recommended protocol as follows: Citric acid, Boehringer-Mannheim kit 139-076 (Boehringer-Mannheim, Indianapolis, Ind.); succinic acid, Boehringer-Mannheim kit 176-281 (Boehringer-Mannheim, Indianapolis, Ind.); formic acid, Boehringer-Mannheim kit 979-732 (Boehringer-Mannheim, Indianapolis, Ind.); acetic acid, Boehringer-Mannheim kit 148-261 (Boehringer-Mannheim, Indianapolis, Ind.); oxalic acid, Boehringer-Mannheim kit 755-699 (Boehringer-Mannheim, Indianapolis, Ind.); and pyruvate, Sigma kit 726-UV (Sigma Chemicals Co, St. Louis, Mo.).
Quantitative PT ELISA Assay: Microtiter plates (Nunc-Immuno Plate IIF, Vangard International, Neptune, N.J.) were sensitized by adding 0.1 ml per well of fetuin (Sigma Chemical Co.) at 0.2 μg/ml in 0.1 M sodium carbonate, pH 9.6, and incubating overnight at room temperature. The plates were washed five times with a solution containing 0.9% NaCl, 0.05% Brij 35, 10 mM sodium acetate at pH 7.0, and 0.02% azide. Samples containing PT were diluted in PBS with 0.5% Brij 35 and added to the plate and incubated for 2 hr at room temperature. The plates were again washed as before and the monoclonal antibody to PT (20.6) was diluted with PBS. Ibsen, et al., Infect. Immun. 61:2408-2418 (1993). The plates were again washed and the secondary antibody, alkaline phosphatase conjugated goat anti-mouse IgG and IgM (Tago Inc., Burlingame, Calif.), was diluted in PBS-Brij, was added to the plates and was then incubated for 2 h at room temperature. The plates were washed as before and p-nitrophenyl phosphate (Sigma Phosphatase Substrate 104) (1 mg/ml), in a solution of 0.1 M diethanolamine, 1 mM MgCl 2 , 0.1 mM ZnCl 2 , and 0.02% azide, at pH 9.8, was added. The plates were incubated at 37° C. for 1 h and the absorbance at 405 nm was determined using a Dynex Model MRX microtiter plate reader (Dynex Technologies, Inc., Chantilly, Va.). For each plate, a standard curve was generated using purified PT (North American Vaccine, Inc.) diluted in 0.1% BSA and 0.1% glycerol in PBS. The concentration of PT from culture samples was calculated from the standard curve.
Sulfate Determinations: Sulfate concentrations within the medium were determined using the methods of Melnicoff, et al. The assay was adapted to a microplate assay. Melnicoff, et al., Res. Commun. Chem. Pathol. Pharmacol. 14:377-386 (1976).
Cloning of the B. pertussis nifS-like gene: The DNA fragment containing the nifS-like gene was amplified by a Perkin-Elmer Thermal Cycler 480. The reaction mixture (50 μl) contained: 20 ng purified B. pertussis chromosomal DNA, 0.2 μM of each primer (forward primer: 5′ ATG AGC MT CGC CCC ATC TAC 3′ (SEQ. ID. NO. 3); reversed primer: 5′CAC TAT TTG GTC GGT CGG 3′ (SEQ. ID. NO.4), 2 mM MgCl 2 , 10 mM Tris-HCl (pH 8.3), 50 mM KCl, 400 μM each dNTP, and 2.5 units of AmpliTaq Gold (Perkin Elmer, Branchburg, N.J.). The conditions were as follows: first cycle, 2 min at 94° C.; subsequent 35 cycles, 94° C. (2 min), 42° C. (1 min), 72° C. (2 min); and with a final 72° C. incubation time for 8 min. The PCR product was gel purified in a 1% agarose gel and ligated into pCR®II-TOPO (Invitrogen, Calrsbad, Calif.) using the conditions recommended by the manufacturer making pBPfilS. The plasmid pBPfilS was transformed into E. coli strain TOPF′ (Invirtogen) and transformants were selected on LB-amp agar media. Sequencing was performed using an Applied Biosystems PRISM Model 310 Automated sequencer (Applied Biosystems, Inc., Foster City, Calif.) using the manufacturer's recommendations and sequencing kit.
Construction of a B. pertussis strain containing a null mutation in the BP filS-like gene: The pBPfilS plasmid made in accordance with the teachings of the present invention was cut with SplI and SphI as well as blunting the ends with the Klenow fragment of DNA polymerase (Boehringer Mannheim). The cut plasmid was gel purified and a blunt-ended erythromycin resistant gene (ermC′) or luciferase was ligated into the plasmid construction. Klugman, et al. Infect. Immun. 57:2066-2071 (1989). Transformants of DH5 were identified having resistance to 100 μg of erythromycin per ml. The constructed plasmid was reisolated using Qiagen columns (Qiagen, Inc., Valencia, Calif.) and the mutated insert was isolated by cutting the plasmid with BamHI and XhoI. The insert was gel purified and ligated into the BamHI and XhoI site of plasmid pSS1129 to make pBPΔfilS. Stibitz, J. Bacteriol. 180:2484-2492 (1998). This was transformed into E. coli strain SM10 and the transformants used to mate with B. pertussis strain BP536 as described by Stibitz. “Use of Conditionally Counterselectable Suicide Vectors for Allelic Exchange,” in Bacterial Pathogenesis, Clark and Bavoil (eds.), p. 301-308 (1997). B. pertussis isolates containing the null BpfilS gene within the chromosome were selected for gentamicin, streptomycin and/or erythromycin resistance or luciferase activity on BGA agar.
Miscellaneous: All materials were purchased from Sigma Chemical Co. and/or of the highest grade available. Total protein was quantified by Coomassie Protein Assays (Pierce Chemical Co., Rockford, Ill.). Human IgG was used as the standard. Bordetella pertussis strain BP536, a spontaneous streptomycin resistant mutant of strain BP338,used in the transformation experiments was obtained from Dr. Scott Stibitz at the Center for Biological Research and Evaluation, United States Food and Drug Administration (Stibitz, S. and M-S. Yang. 1991. J. Bact. 173:4288-4296). The transformed B. pertussis knockout mutant derived therefrom was designated strain BP536pWY and has been deposited with the American Type Culture Collection, (Manassas, Va.) in accordance with the terms of the Budapest Treaty. The American Type Culture Collection has assigned B. pertussis strain BP536pWY ATCC number PTA-3254. All methods employed are all well known to those of ordinary skill in the art. See for example: Methods in Molecular Biology, vol XX, B. D. Shepard and M. S. Gilmore (eds) (1995); DNA Sequencing, L. Alphey. Bios Scientific Publishers (1997); Diagnostic and Molecular Microbiology: Principles and Applications, D. H. Persing, T. F. Smith, F. C. Tenover and T. J. White (eds) (1993) American Society for Microbiology; Molecular Biology, D. Freifelder (ed) (1987) Jones and Bartlett Publishers; and Molecular Biology of the Gene, J. D. Watson, N. H. Hopkins, J. W. Roberts, J. A. Steiz and A. M. Weiner (eds) (1987) The Bengerman/Cummings Publishing Company, Inc.
Results
Detection of Inhibitor(s) of PT production in broth cultures of BP: Samples were taken at various times during the growth phase of the BP cultures. The samples were monitored for BP growth by measuring the OD 650 and for the production of PT by ELISA. The results were calculated as PT in microgram/per ml/OD 650 in order to approximate the amount of PT produced per cell. As shown in FIG. 1 , the amount of PT produced per cell fell drastically midway through the growth cycle. Although B. pertussis continued in logarithmic phase growth, the production of PT appeared to decrease almost to the total elimination of PT production. This suggested that an inhibitor of PT production was being generated during the early phases of the culture and that after reaching inhibitory concentration, PT production ceased. To test this hypothesis, culture supernatant from a B. pertussis culture grown to stationary phase was lyophilized and was reconstituted with growth media lacking the basic salts. This mixture was then used to grow a second culture of B. pertussis and was compared to the original media used for B. pertussis . Samples were taken and assayed as before. The growth of B. pertussis in each of the two media was similar with the OD 650 reaching approximately the same levels. However, the total amount of PT produced in the reconstituted mixture was drastically reduced compared to that in the original media. A more visual demonstration of such an inhibition, and that this inhibitor also effects the production of adenylate cyclase, the cause of haemolysis on blood agar plate, is shown in FIG. 2 . An initial streak of B. pertussis was made on a BGA plate and allowed to grow for 48 hrs. Secondary cross-streaks were then made and the agar plate was incubated for an additional 48 hrs. It can be seen that a zone of non-haemolysis radiates out from the initial growth streak. Characterization of the inhibitor began by filtering the spent culture media through a 3,000 MWCO filter retaining both the permeate and the filtrate. Both were lyophilized and reconstituted as before. FIG. 3 demonstrates the results of the B. pertussis grown in these mixtures as compared to the GMAR media. The production of PT was inhibited by the permeate mixture suggesting that the inhibitor had a molecular weigh smaller than 3,000.
Amino Acid and Organic Acid Analysis: Both amino acid and organic acid analysis were performed on samples taken at different times during the course of a typical B. pertussis culture in order to determine whether the rise and/or the timing of the increase in these compounds correlated with the timing of the production inhibition of PT. These data are shown in FIGS. 4 a and 4 b . It should be noted that the drop in PT production occurs at approximately half way through the growth phase, typically at 20 h. Three compounds appear and continue to increase in concentration around this time period: methionine, cysteine, and pyruvic acid. The rise in methionine seems to occur first, followed by cysteine and pyruvic acid. Many pathways link the metabolism of methionine to cysteine. However, few pathways generate pyruvate from cysteine. Three such pathways are shown in Leninger, A. L., Biochemistry, Worth Publishers, pp. 441 (1970). In each of these three pathways, the sulfur group of cysteine is removed and pyruvate is generated thereby linking the rise of each of these compounds with each other as well as to an increase of sulfate within the media.
Sulfate Production within B. pertussis culture: The concentration of sulfate was determined on each of the culture samples and compared with B. pertussis growth (OD 650 ) and time. FIG. 5 illustrates the results of these determinations on the same samples used to generate the data in FIG. 4 . The data demonstrate that at the approximate time when methionine, cysteine, and finally pyruvate increased in concentration, there was also a large increase in the production of sulfate.
Growth of B. pertussis and the production of PT in the presence of BaCl 2 : The sulfate ion is a modulator of B. pertussis from the virulent phase to the avirulent phase. This modulation is regulated by the proteins BvgS and BvgA which are members of a large family of two component regulatory molecules. Although it has been known for some time that the addition of extraneous sulfate would down regulate the production of several of the virulence factors including PT (Weiss and Hewlett, Ann. Rev. Microbiol. 40:661-686 (1986)), the identification of the compound or compounds that interact with this system remained unknown. In order to determine whether the possible generation of sulfate from cysteine catabolism or another source during the course of B. pertussis growth might affect PT production, a way was sought to either inactivate or remove the influence of sulfate from the culture. Barium in the form of BaCl 2 is highly soluble in water (1.8 M at 25° C. and 2.8 M at 100° C.), whereas BaSO 4 is highly insoluble (10.7 μM at 25° C. and 17.7 μM at 100° C.). This difference in solubility has often been used to precipitate sulfate out of solution for further measurement. Different concentrations of BaCl 2 were added to the growth media and the growth and production of PT in the culture were compared. These data are shown in FIG. 5 . The addition of the BaCl 2 at both concentrations enhanced the production of PT per cell in both B. pertussis strains as compared to the normal media, albeit more in strain 9797. It should also be noted that a visible precipitate could be seen accumulating over time in the culture, presumably BaSO 4 . These data suggest that the negative feedback inhibitor of PT within the culture is sulfate.
Cloning of a Cysteine Sulfinate Desulfinase gene from BP: One of the possible enzymes responsible for the removal of sulfur from cysteine, nifS-like genes, has been cloned and characterized from E. coli . Mihara et al., J. Biol. Chem. 272:22417-22424 (1997). Using this sequence, a homology was sought in the partial B. pertussis genome data base. An open reading frame demonstrating high homology to the nifS genes was found and appropriate PCR primers were synthesized. A PCR product of the appropriate size was generated using B. pertussis chromosomal DNA, was cloned into a TA cloning vector PCR®II-TOPO and was sequenced using methods known to those of ordinary skill in the art ( FIG. 7 ).
Peptide synthesis and purification: A peptide containing the sequence GGGDGSFSGFGDGSFSGFG-OH (SEQ. ID. NO. 5) was synthesized by The Rockefeller University Protein Sequencing Facility using NMP t-butoxycarbonyl chemistry on an ABI 430A peptide synthesizer (Applied Biosystems, Foster City, Calif.). The peptide was deprotected and removed from the resin by treatment with HF in the presence of anisole (0° C./1 h). Preparative purification of the peptide was performed using a C-18 column (2.14 ID×30 cm)(Dynamax-Rainin, Woburn, Mass.). The peptide was quantitated by PTC amino acid analysis using a Waters Picotag system (Waters, Milford, Mass.). The synthesized peptide elute from the C-18 column as a major peak consisting of 95% of the total elution profile. The amino acid composition of the purified peptide was in good agreement with the sequence which was used to synthesize the peptide.
Construction of the peptide affinity column: Superose® 6B was activated using the method described by Brandt, et al., Biochim. Biophys. Acta 386:196-202 (1975). Briefly, a 50% gel slurry of pre-washed Superose® 6B in 0.1 M NaHPO 4 , pH 8.0, was treated with a solution of 250 mM p-benzoquinone in ethanol to give a final concentration of 20% ethanol and 50 mM p-benzoquinone. The suspension was gently shaken for 1 h at room temperature. The activated Superose® 6B was then extensively washed on a coarse disc sintered glass funnel with 2 volumes each of 20% ethanol, deionized H 2 O, 1 M NaCl, and once again with deionized H 2 O. The activated Superosee 6B was aspirated to a compact cake and one volume of a solution containing 2 mg/ml of the peptide in 0.1 M NaHPO 4 , pH 8.0, was added and the mixture rotated end-over-end for 24 h at 4° C. 1.0 M ethanolamine, pH 8.0, was then added and the rotation continued for 1 h at room temperature. The gel matrix was then wash extensively with deionized H 20 , 1.0 M NaCl in 0.1 M NaHPO 4 , pH 7.0. Aliquots of the initial peptide solution and the supernatant directly after the coupling step were retained and measured by A 280 using a Shimadzu UV Spec 120 (Shimadzu, Columbia, Md.) to determine the incorporation of the peptide onto the Superose® 6B.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions without undue experimentation. All patents, patent applications and publications cited herein are incorporated by reference in their entirety. | Methods and compositions are provided for the enhanced production of bacterial toxins in large-scale cultures. Specifically, methods and compositions for reducing bacterial toxin expression inhibitors are providing including, but not limited to, addition of toxin expression inhibitor binding compounds, culture media having reduced concentrations of toxin inhibitor metabolic precursors and genetically modified toxogenic bacteria lacking enzymes required to metabolize the toxin inhibitor metabolic precursors. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to the field of earth working implements and more specifically to that class of implements useful in the planting of seed beds for the production of grass sod.
The use of pregrown grass sod is well-known and is commonly used in landscaping when it is undesireable to plant and grow seed in the area where grass is desired. For such purposes, sod is grown in large agricultural areas referred to as sod farms wherein the grass sod is grown as a corp. After the sod is grown it is harvested by cutting below the soil level of the grass roots and rolling up the sod for transporting to and transplanting at the desired site.
Inasmuch as the sod is bound together solely by the root system of the grass itself, it is somewhat fragile and subject to breaking and tearing apart. In order to alleviate this problem, which can result in costly losses and unusable sections of sod, a plastic netting has been devised for use in strengthening the sod. Such netting is produced in a fenestrated pattern of about one inch squares and is laid under the topsoil in which the grass seed has been planted. As the grass root system grows, it is intimately intertwined in the netting whereby the netting lends support to the roots and hence the sod. When the sod is cut and harvested the netting remains in the cut soil layer to lend strength and stability to the sod.
While the use of such netting has been shown to be desirable, heretofore no satisfactory method of automatically laying and burying such netting in a seed bed had been developed, especially in a large commerical operation where several acres or hundreds of acres of sod is grown at a time.
Prior attempts have been directed to forcing the netting down into the topsoil through the use of rolling force or pressure from about. This technique has not proved successful in seating the netting at the appropriate level and establishing a satisfactory sod bed.
The present invention overcomes the disadvantages of the prior art techniques and provides an apparatus whereby netting can be installed under the seeded topsoil in an automatic fashion to a controllable depth without harming the seed bed itself. These and other advantages of the present invention will become obvious as the description proceeds.
SUMMARY OF THE INVENTION
The present invention provides an earth working implement adapted to be drawn behind a tractor, said tractor also providing driving power for the moving portions of the implement. The implement includes a drive means; an earth engaging assembly having a plurality of orbiting blades for scooping topsoil and transporting it to a discharge point; a net carrying and dispensing means for laying netting from a roll along the ground, the earth engaging assembly depositing the topsoil onto the netting as it is laid. The orbital speed of the earth engaging assembly can be adjusted to provide any desired depth of topsoil and the implement preferably includes a following roller for compacting and smoothing the net containing seed bed. Appropriate hydraulic cylinders and chain drives are provided for moving and operating the components of the implement.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a prespective view of the earth working implement of the present invention showing it in a trailing position behind a tractor;
FIG. 2 is a top plan view of the implement of FIG. 1;
FIG. 3 is a side view in elevation of the implement in an operating position for dispensing netting; and,
FIG. 4 is another side elevational view similar to FIG. 3 in which the implement is in a non-operating, traveling position.
DESCRIPTION OF PREFERRED EMBODIMENTS
The perspective view of FIG. 1 depicts the earth working apparatus of the present invention in an operating configuration. The implement, designated generally at 10, is adapted to be towed behind a tractor 11 which provides both the movement of the implement and also the power for its moveable element through a standard tractor power take-off 12.
The implement includes a heavy frame 13, shown clearly in FIG. 2, comprising longitudinal members 14 and lateral members 15. Legs 16 depend from the longitudinal members 14, said legs in turn supporting a crosspiece 17. Mounted on the crosspiece 17 is a roller 18, rotatably mounted on plate portions 19 of the crosspiece 17.
Support arms 20 extend forwardly from the plate portions 19, the support arms providing a bracket 21 at their outer ends, the brackets adapted to receive a roll of standard sod netting therebetween. The net roll 22 can be sleeved over a carrier 23 to be carried by the brackets 21 at each end of the roll in a manner allowing the roll to rotate and allow the net to be unrolled therefrom.
Mounted between the longitudinal members 14 at their rearmost ends is a cross-member 24 which is mounted to allow it to rotate about a horizontal axis. Braces 25 are attached to the cross-member 24, the braces 25 in turn supporting an axle 26 to which are mounted wheels 27. An arm 28 is fixed to the cross-member 24 toward the mid-point thereof, and a hydraulic cylinder 29 is attached to the lower portion of the arm 28 below the axis of rotation of cross-member 24. The piston rod 30 of the cylinder is fixed to brace 31 which forms part of the frame 13.
A generally flat, pan-shaped apron 32 is mounted in the forward end of the frame 13. The apron 32 includes side walls 33 and an axle 34 is mounted in each end of the side walls, the axles 34 extending horizontally across apron 32. Sprockets 35 are attached to the axles 34 at their ends, the sprockets being interconnected on each side by means of chains 36 which run along and generally follow the perimeter contour of side walls 33. When the sprockets 35 are rotated, the chains 36 move in an orbital path between the front and rear sprockets generally along the perimeter of the side walls 33.
A plurality of L-shaped blades 37 are mounted across the apron 32 parallel to the axles 34 and operably connected to the chains 36 to be driven thereby. The blades 37 are installed so that one leg of the L lies flat on the apron 32 while the other leg protrudes from the apron in a direction which stays generally perpendicular thereto throughout the travel of the blades along the orbital path.
A shroud cover 51 overlies the foreward portion of the apron 32, beginning at a point at the leading edge and curving around the front of the apron and the forwardmost portion of the top surface of the apron. Wheels 52 are mounted at each end of the forward axle 34.
An elongated cross-member 38 is mounted between the longitudinal members 14 at the forwardmost ends thereof. A rotatable member 39 is mounted to and vertically adjacent crossmember 38 to be supported thereby. An arm 40 is rigidly attached to each end of member 39 and a third arm 41 is attached to the member 39 at approximately the center thereof. The center arm 41 and the pair of end arms 40 are offset from each other approximately 90 degrees. Center arm 41 is connected to arm 28 by means of a chain or cable 42. End arms 40 are attached to the forwardmost portion of apron 32 by means of chains or cables 43.
A driveshaft 44 extends rearwardly from the power take-off 12 to a gear box 45 mounted to the cross-member 38. A second driveshaft 46 extends from the gear box 45 to a drive sprocket at its end, the sprocket being hidden in the drawings by chain guard 47. A drive chain carried inside guard 47 extends from the sprocket to a similar sprocket attached to axle 34 at the rearmost end of apron 32.
Completing the forward end of frame 13 is a pair of forward members 48 connected by crosspiece 49 to which tongue 50 is attached, the tongue being adapted for connection to the tractor 11.
OPERATION
The operation of the implement can best be understood by reference to FIGS. 3 and 4. In FIG. 3 the implement is in an operating position wherein roller 18, wheels 52, and the leading edge of apron 32 are in contact with the ground. The net roll 22 may also lie on the ground although it can be slightly above ground as actual contact is not essential. The soil to be worked has been prepared by plowing and discing to produce a smooth, loose topsoil. The grass seed can have already been spread on or in the topsoil or it can be added after the netting is installed if desired. Good results have been obtained when the seed is already spread in the topsoil.
Power from the power take-off 12 is transmitted through the driveshafts 44 and 46 to the apron chain drive. The drive chains 35 are caused to orbit about axles 34, driving the blades 37 in a generally clockwise orbital path as viewed in the drawings. The blades scoop up the topsoil as they pass around the front sprocket 35 and carry it upwardly and rearwardly along the apron 32. The shroud cover 51 prevents the soild from being thrown forwardly off the apron and instead keeps the soil on the blades 37 until they have rotated to the top surface of the apron 32. When the blades reach the rear sprockets 35 and pass around the rearmost axle 34, the soil is deposited from the back of the apron 32, falling between the net roll 22 and roller 18.
The netting from roll 22 is unwound in a counterclockwise direction from the bottom of the roll, passing under roller 18. As the implement is pulled along the ground, the weight and pressure of roller 18 pulls the netting from the roll 22. The soil falling from the apron falls upon and covers the netting. The precise depth of topsoil deposited on the netting is a function of the forward speed of the tractor and the orbital speed of the blades 37. These parameters can be easily adjusted to provide an optimum depth of soil on the netting.
The following roller 18 passes over the freshly deposited topsoil and provides the proper compaction to firmly seat the netting, soil and seed on the ground.
When it is desired to trail the implement in a non-operating travel mode, hydraulic cylinder 29 is actuated to its closed or compressed position. This action pulls the lower portion of arm 28 forwardly, causing the braces 25 and hence wheels 27 to move forwardly as well. Because of the length of braces 25 this causes the central portion of the implement, namely roller 18 and net roll 22 to be raised off the ground. At the same time, chain 42 pulls arm 41 rearwardly, rotating arms 40 upwardly and lifting the leading edge of apron 32 up off the ground. When cylinder 29 is in its fully retracted position the implement is in the configuration shown in FIG. 4.
Thus it can be seen that the apparatus of the present invention effectively installs the netting below the topsoil surface by lifting a portion of the topsoil, laying the netting down on the ground from which the soil has been lifted, and redepositing the soil over the netting. The following roller compacts the soil and netting into place. The result is a smooth seeded bed with the netting in place under the desired depth of topsoil.
While the precise structure of the implement has been described in detail for purposes of complete explanation, it will be understood that various modifications can be made in the apparatus by those skilled in the art without departing from the spirit of the invention, whose scope is to be defined in the appended claims. | An earth working implement is disclosed for installing plastic netting under seeded earth for the growth of grass sod. The implement may be drawn by a tractor and is configured to continuously lay netting on the ground and automatically cover the netting with an appropriate layer of earth containing seed. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application is related to commonly owned copending Provisional Application Ser. No. 60/026,716, filed Sep. 26, 1996, and claims the benefit of its earlier filing date under 35 U.S.C. 119(e).
FIELD OF THE INVENTION
This invention relates to active derivatives of poly(ethylene glycol) and related hydrophilic polymers with a reactive moiety at one end of the polymer chain suitable for chemical coupling to another molecule.
BACKGROUND OF THE INVENTION
Chemical attachment of the hydrophilic polymer poly(ethylene glycol) (PEG), which is also known as poly(ethylene oxide) (PEO), to molecules and surfaces is of great utility in biotechnology. In its most common form PEG is a linear polymer terminated at each end with hydroxyl groups:
HO—CH 2 CH 2 O—(CH 2 CH 2 O) n —CH 2 —CH 2 OH
This polymer can be represented in brief form as HO-PEG-OH where it is understood that the -PEG- symbol represents the following structural unit:
—CH 2 CH 2 O—(CH 2 CH 2 O) n —CH 2 CH 2 —
In typical form n ranges from approximately 10 to approximately 2000.
PEG is commonly used as methoxy-PEG-OH, or mPEG, in which one terminus is the relatively inert methoxy group, while the other terminus is a hydroxyl group that is subject to ready chemical modification.
CH 3 O—(CH 2 CH 2 O) n —CH 2 CH 2 —OH mPEG
PEG is also commonly used in branched forms that can be prepared by addition of ethylene oxide to various polyols, such as glycerol, pentaerythritol and sorbitol. For example, the four-arm, branched PEG prepared from pentaerythritol is shown below:
C(CH 2 —OH) 4 +n C 2 H 4 O→C[CH 2 O—(CH 2 CH 2 O) n —CH 2 CH 2 —OH] 4
The branched polyethylene glycols can be represented in general form as R(-PEG-OH) n in which R represents the central “core” molecule, such as glycerol or pentaerythritol, and n represents the number of arms.
PEG is a well known polymer having the properties of solubility in water and in many organic solvents, lack of toxicity, and lack of immunogenicity. One use of PEG is to covalently attach the polymer to insoluble molecules to make the resulting PEG-molecule “conjugate” soluble. For example, Greenwald, Pendri and Bolikal in J. Org. Chem., 60, 331-336 (1995) have shown that the water-insoluble drug taxol, when coupled to PEG, becomes water soluble.
In related work, Davis et al. in U.S. Pat. No. 4,179,337 have shown that proteins coupled to PEG have enhanced blood circulation lifetime because of reduced rate of kidney clearance and reduced immunogenicity. Hydrophobic proteins have been described that gain increased water solubility upon coupling to PEG. These applications and many leading references are described in the book by Harris (J. M. Harris, Ed., “Biomedical and Biotechnical Applications of Polyethylene Glycol Chemistry,” Plenum, New York, 1992).
To couple PEG to a molecule such as a protein or on a surface, it is necessary to use an “activated derivative” of the PEG having a functional group at the terminus suitable for reacting with some group on the surface or on the protein (such as an amino group). Among the many useful activated derivatives of PEG is the succinimidyl “active ester” of carboxymethylated PEG as disclosed by K. Iwasaki and Y. Iwashita in U.S. Pat. No. 4,670,417. This chemistry can be illustrated with the active ester reacting with amino groups of a protein (the succinimidyl group is represented as NHS and the protein is represented as PRO—NH 2 ):
PEG-O—CH 2 —CO 2 —NHS+PRO—NH 2 →PEG-O—CH 2 —CO 2 —NH—PRO
Problems have arisen in the art. Some of the functional groups that have been used to activate PEG can result in toxic or otherwise undesirable residues when used for in vivo drug delivery. Some of the linkages that have been devised to attach functional groups to PEG can result in an undesirable immune response. Some of the functional groups do not have appropriate selectivity for reacting with particular groups on proteins and can tend to deactivate the proteins.
Attachment of a PEG derivative to a substance can have a somewhat unpredictable impact on the substance. Proteins, small drugs, and the like can have less biological activity when cojugated with a PEG derivative. For others, activity is increased.
Another example of a problem that has arisen in the art is exemplified by the succinimidyl succinate “active ester” mPEG-SS (the succinimidyl group is represented as NHS):
The mPEG-SS active ester is a useful compound because it reacts rapidly with amino groups on proteins and other molecules to form an amide linkage (—CO—NH—). A problem with the mPEG-SS active ester, which was recognized by K. Iwasaki and Y. Iwashita in U.S. Pat. No. 4,670,417, is that this compound possesses an ester linkage in the backbone that remains after coupling to an amine such as a protein (represented as PRO—NH 2 ):
mPEG-SS+PRO—NH 2 →mPEG-O 2 C—CH 2 CH 2 —CONH—PRO
The remaining ester linkage is subject to rapid hydrolysis and detachment of PEG from the modified protein. Too rapid hydrolysis can preclude use of a PEG derivative for many applications. Several approaches have been adopted to solve the problem of hydrolytic instability. For example, mPEG succinimidyl carbonate has been proposed, which contains only ether linkages in the polymer backbone and reacts with proteins to form a conjugate that is not subject to hydrolysis.
It would be desirable to provide alternative PEG derivatives that are suitable for drug delivery systems, including delivery of proteins, enzymes, and small molecules, or for other biotechnical uses. It would also be desirable to provide alternative PEG derivatives that could enhance drug delivery systems or biotechnical products.
SUMMARY OF THE INVENTION
The invention provides chemically active polyethylene glycols and related polymers that are suitable for coupling to other molecules to give water-soluble conjugates, and in which the linkage between the polymer and the bound molecule is subject to predetermined cleavage for controlled delivery of the bound molecule into the surrounding environment.
The PEG and related polymer derivatives of the invention contain weak, hydrolytically unstable linkages near the reactive end of the polymer that provide for a sufficient circulation period for a drug-PEG conjugate and then hydrolytic breakdown of the conjugate and release of the bound molecule. Methods of preparing the active PEGs and related polymers, PEG conjugates, and methods of preparing the PEG conjugates are also included in the invention.
The PEG and related polymer derivatives of the invention are capable of imparting water solubility, size, slow rate of kidney clearance, and reduced immunogenicity to the conjugate, while also providing for controllable hydrolytic release of the bound molecule into the aqueous environment by design of the linkage. The invention can be used to enhance solubility and blood circulation lifetime of drugs in the blood stream and then to deliver a drug into the blood stream substantially free of PEG. In some cases, drugs that previously had reduced activity when permanently conjugated to PEG can have therapeutically suitable activity when coupled to a degradable PEG in accordance with the invention.
In general form, the derivatives of the invention can be described by the following equations:
In the above equations,
“Poly” is a linear or branched polyethylene glycol of molecular weight from 300 to 100,000 daltons. Poly can also be a related nonpeptidic polymer as described in the Detailed Description;
n is the number of chemically active end groups on Poly and is the number of molecules that can be bound to Poly;
W is a hydrolytically unstable weak group;
T is a reactive group;
(Y—P′) n represents a molecule for conjugation to Poly, in which Y is a reactive group that is reactive with T and P′ is the portion of the molecule that is to be bound and released, including, for example, a peptide P′ in which Y is an amine moiety and T is a PEG activating moiety reactive with amine moieties;
X is the new linkage formed by reaction of Y and T; and
G and I are new groups formed by hydrolysis of W.
Examples of hydrolytically unstable groups W include carboxylate esters, phosphate esters, acetals, imines, orthoesters, peptides and oligonucleotides. T and Y are groups reactive toward each other. There are many examples of such groups known in organic chemistry. Some examples include active esters reacting toward amines, isocyanates reacting toward alcohols and amines, aldehydes reacting toward amines, epoxide reacting toward amines, and sulfonate esters reacting toward amines. Examples of P′ include peptide, oligonucleotide and other pharmaceuticals. Examples of X include amide from reaction of active esters with amine, urethane from reaction of isocyanate with hydroxyl, and urea from reaction of amine with isocyanate. Examples of G and I are alcohol and acid from hydrolysis of carboxylate esters, aldehyde and alcohol from hydrolysis of acetals, aldehydes and amine from hydrolysis of imines, phosphate and alcohol from hydrolysis of phosphate esters, amine and acid from hydrolysis of peptide, and phosphate and alcohol from hydrolysis of oligonucleotides.
An example of the invention is shown in the following equation for conjugation of methoxy-PEG-OH (mPEG) with a peptide drug and for hydrolytic release of the peptide drug. The weak linkage W in the conjugate is an ester group.
The released peptide contains no mPEG. The released peptide contains an additional short molecular fragment, which is sometimes called a “tag” and is the portion of the linkage opposite the PEG from the hydrolytically unstable linkage.
Thus, the invention provides hydrolytically unstable linkages in activated PEGs and related polymers that are suitable for controlled delivery of drugs from conjugation with the PEG to the surrounding environment. Several types of linkages, including ester linkages, are suitable for use in the invention. However, the ester linkages of the invention, in contrast to mPEG-SS and mPEG-SG, provide for variation and control of the rate of hydrolytic degradation.
The foregoing and other objects, advantages, and features of the invention, and the manner in which the same are accomplished, will be more readily apparent upon consideration of the following detailed description of the invention taken in conjuntion with the accompanying drawings, which illustrates an exemplary embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 through 3 are illustrations of MALDI-MS spectra of the molecular weight distribution of an mPEG-HBA and subtilisin conjugate at different times after preparation.
FIG. 1 is 1 day.
FIG. 2 is 8 days.
FIG. 3 is 14 days.
DETAILED DESCRIPTION
The following detailed description describes various examples of the derivatives of the invention as described by the following general equations presented in the summary:
In the discussion below, Poly will often be referred to for convenience as PEG or as poly(ethylene glycol). However, it should be understood that other related polymers are also suitable for use in the practice of the invention and that the use of the term PEG or poly(ethylene glycol) is intended to be inclusive and not exclusive in this respect.
Poly(ethylene glycol) is useful in the practice of the invention. PEG is used in biological applications because it has properties that are highly desirable and is generally approved for biological or biotechnical applications. PEG typically is clear, colorless, odorless, soluble in water, stable to heat, inert to many chemical agents, does not hydrolyze or deteriorate, and is nontoxic. Poly(ethylene glycol) is considered to be biocompatible, which is to say that PEG is capable of coexistence with living tissues or organisms without causing harm. More specifically, PEG is not immunogenic, which is to say that PEG does not tend to produce an immune response in the body. When attached to a moiety having some desirable function in the body, the PEG tends to mask the moiety and can reduce or eliminate any immune response so that an organism can tolerate the presence of the moiety. Accordingly, the activated PEGs of the invention should be substantially non-toxic and should not tend substantially to produce an immune response or cause clotting or other undesirable effects.
Other water soluble polymers than PEG are suitable for similar modification. These other polymers include poly(vinyl alcohol) (“PVA”); other poly(alkylene oxides) such as poly(propylene glycol) (“PPG”) and the like; and poly(oxyethylated polyols) such as poly(oxyethylated glycerol), poly(oxyethylated sorbitol), and poly(oxyethylated glucose), and the like. The polymers can be homopolymers or random or block copolymers and terpolymers based on the monomers of the above polymers, straight chain or branched, or substituted or unsubstituted similar to mPEG and other capped, monofunctional PEGs having a single active site available for attachment to a linker.
Specific examples of suitable additional polymers include poly(oxazoline), poly(acryloylmorpholine) (“PAcM”), and poly(vinylpyrrolidone)(“PVP”). PVP and poly(oxazoline) are well known polymers in the art and their preparation and use in the syntheses described for mPEG should be readily apparent to the skilled artisan. PAcM and its synthesis and use are described in U.S. Pat. Nos. 5,629,384 and 5,631,322, the contents of which are incorporated herein by reference in their entirety.
It should be understood that by “drug” is meant any substance intended for the diagnosis, cure, mitigation, treatment, or prevention of disease in humans and other animals, or to otherwise enhance physical or mental well being. The invention could be used for delivery of biologically active substances generally that have some activity or function in a living organism or in a substance taken from a living organism.
The terms “group,” “functional group,” “moiety,” “active moiety,” “reactive site,” and “radical” are all somewhat synonymous in the chemical arts and are used in the art and herein to refer to distinct, definable portions or units of a molecule and to units that perform some function or activity and are reactive with other molecules or portions of molecules.
The term “linkage” is used to refer to groups that normally are formed as the result of a chemical reaction and typically are covalent linkages. Hydrolytically stable linkages means that the linkages are stable in water and do not react with water at useful pHs for an extended period of time, potentially indefinitely. Hydrolytically unstable linkages are those that react with water, typically causing a molecule to separate into two or more components. The linkage is said to be subject to hydrolysis and to be hydrolyzable. The time it takes for the linkage to react with water is referred to as the rate of hydrolysis and is usually measured in terms of its half life.
The invention includes poly(ethylene glycols) containing ester groups as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules to be delivered in vivo or into a substance taken from a living entity:
ti PEG-W—CO 2 —NHS
Where W =
—O 2 C—(CH 2 ) n —O—
n = 1-5
—O—(CH 2 ) n —CO 2 —(CH 2 ) m —
n = 1-5, m = 2-5
—O—(CH 2 ) n —CO 2 —(CH 2 ) m —O—
n = 1-5, m = 2-5
The invention includes poly(ethylene glycols) containing ester groups as weak linkages and isocyanates as reactive groups useful for coupling to amine- and alcohol-containing molecules:
PEG-W—N═C═O
Where W=—O—(CH 2 ) n —CO 2 —(CH 2 ) m — n=1 to 5, m=2 to 5
The invention includes poly(ethylene glycols) containing acetal groups as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules:
PEG-W—CO 2 —NHS
For example
The invention included poly(ethylene glycols) containing imine groups as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules:
PEG-W—CO 2 —NHS
Where
W=—Z—CH═N—(CH 2 ) m —O— m=1-5 and where Z=—O—C 6 H 4 — and —O—(CH 2 ) m —CH 2 — m=1-5
The invention also includes poly(ethylene glycols) containing phosphate ester groups as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules:
PEG-W—CO 2 —NHS
Where
W=—(CH 2 ) n —OPO 3 —(CH 2 ) m — n and m=1-5
The invention includes poly(ethylene glycols) containing ester-linked amino acids as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules. An advantage of this derivative is that hydrolytic breakdown leaves a biologically acceptable amino acid attached to the released molecule:
PEG-W—CO 2 —NHS
Where
W=—O—(CH 2 ) n —CO 2 —(CH 2 ) m —CH(NH-t-Boc)— n=1-5, m=1-5
t-Boc=(CH 3 ) 3 C—O—CO—
The invention includes poly(ethylene glycols) containing peptides as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules. An advantage of this derivative is that hydrolytic breakdown leaves a usually biologically acceptable peptide fragment attached to the released molecule:
PEG-W—CO 2 —NHS
Where
W=—CO(NH—CHR—CO) n —NH—CHR— n=2-20
R=the set of substituents typically found on α-amino acids
The invention includes poly(ethylene glycols) containing oligonucleotides as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules. An advantage of this derivative is that hydrolytic breakdown leaves the biologically acceptable oligonucleotide fragment attached to the released molecule:
PEG-W—CO 2 —NHS
Where W=oligonucleotide
It should also be recognized that branched activated PEGs can be prepared in accordance with the invention having weak linkages near the reactive end of the polymer for controlled hydrolytic degradation. Suitable branched PEGs can be prepared in accordance with U.S. Pat. No. 5,932,462, the contents of which are incorporated herein in their entirety by reference. These branched PEGs can then be modified in accordance with the present teachings.
The invention is illustrated with respect to several specific examples below, including determination of hydrolysis half lives for specific derivatives.
Example 1
Preparation of CH 3 O-PEG-O—(CH 2 ) n —COO—CH 2 —COOH (n=1: mPEG-CM—GA—NHS, and n=2: mPEG-PA—GA—NHS)
Reactions
CH 3 O-PEG-O—(CH 2 ) n —COOH 3000 (3.0 g, 1 mmole, mPEG-CM or mPEG-PA) was azeotropically dried with 60 ml of toluene under N 2 . After two hours, the solution was cooled to room temperature,and thionyl chloride solution (2 ml, 4 mmole) in CH 2 CL 2 was injected. The solution was stirred at room temperature overnight. The solvent was condensed on a rotary evaporator and the residual syrup was dried in vacuo for about four hours over P 2 O 5 powder. Glycolic acid (0.2 g, 2.7 mmole) was azeotropically distilled with 70 ml of 1,4-dioxane and the distillation was stopped when approximately 20 ml of solution remained. The solution was slowly cooled to room temperature under N 2 . The glycolic acid/dioxane solution was then added to the dried PEG acyl chloride. After the PEG was dissolved, 0.6 ml of dry triethylamine was injected to the system (precipitate formed immediately) and the solution was stirred overnight. The salt was removed by filtration and the filtrate was condensed on a rotary evaporator at 55° C. and dried in vacuo. The crude product was then dissolved in 100 ml of distilled water and the pH of the solution was adjusted to 3.0. The aqueous phase was extracted three times with a total of 80 ml of methylene chloride. The combined organic phase was dried over sodium sulfate, filtered to remove salt, condensed on a rotary evaporator, and added to 100 ml of ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 2.55 g (85%). 1 H NMR(DMSO-d 6 ): δ3.5 (br m, PEG), 4.3-4.6 (s, PEGCOOC H 2 COOH), 2.59 (t, PEGOCH 2 C H 2 COO (PA)), 4.19 (s, PEGOC H 2 COO (CM)).
Example 2
Preparation of HOOC—CH 2 —OOC—CH 2 —O-PEG-O—CH 2 —COO—CH 2 —COOH
Reactions
Difunctional carboxymethyl PEG-ester benzyl glycolate 20,000: Difunctional carboxymethyl PEG 20,000 (4 gram, 0.4 mmole acid group), benzyl glycolate (0.6 mmole), dimethylaminopyridine (0.44 mmole), 1-hydroxybenzotriazole (0.4 mmole) and dicyclohexylcarbodiimide (0.56 mmole) were dissolved in 40 ml of methylene chloride. The solution was stirred at room temperature under N 2 overnight. The solvent was then removed under vacuum and the resulting residue was added to 20 ml of toluene at 40° C. The undissolved solid was removed by filtration and the filtrate was added to 200 ml of ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 4 gram (100%). 1 H NMR(DMSO-d 6 ): δ3.5 (br m, PEG), 4.81 (s, PEGCOOC H 2 COOCH 2 C 6 H 5 ), 5.18 (s, PEGOCH 2 COOCH 2 COOC H 2 C 6 H 5 ), 7.37 (s, PEGOCH 2 COOCH 2 COOCH 2 C 6 H 5 ), 4.24 (s, PEGOCH 2 COOCH 2 COOCH 2 C 6 H 5 ).
Difunctional carboxymethyl PEG-ester benzyl glycolate 20,000 (3 gram) and Pd/C (10%, 0.8 gram) were added to 30 ml of 1,4-dioxane. The mixture was shaken with H 2 (40 psi) at room temperature overnight. The Pd/C was removed by filtration and the solvent was condensed by rotary evaporation. The resulting syrup was added to 100 ml of ether. The precipitated product was collected by filtration and dried in vacuo. Yield 2.4 gram (80%). 1 H NMR(DMSO-d 6 ): δ3.5 (br m, PEG), 4.56 (s, PEGCOOC H 2 COOH), 4.20 (s, PEGOC H 2 COOCH 2 COOH).
Example 3
Preparation of CH 3 O-PEG-O—(CH 2 ) n —COO—CH 2 —COONHS
Reactions
CH 3 O-PEG-O—(CH 2 ) n —COO—CH 2 —COOH (1 g, approx. 0.33 mmole) and 42 mg N-hydroxysuccinimide (NHS) (0.35 mmole) was dissolved in 30 ml of dry methylene chloride. To it was added dicyclohexylcarbodiimide (DCC) (80 mg, 0.38 mmole) in 5 ml of dry methylene chloride. The solution was stirred under nitrogen overnight and the solvent was removed by rotary evaporation. The resulting syrup was redissolved in 10 ml of dry toluene and the insoluble solid was filtered off. The solution was then precipitated into 100 ml of dry ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 0.95 g (95%). 1 H NMR (DMSO-d 6 ): δ3.5 (br m, PEG), 5.15-5.21 (s, PEGCOOC H 2 COONHS), 2.67 (t, PEGOCH 2 C H 2 COO (PA)), 4.27 (s, PEGOC H 2 COO ppm(CM)), 2.82 (s, NHS, 4H).
Example 4
Preparation of
Reactions
CH 3 O-PEG-O—(CH 2 ) n —COO—CH 2 —COOH (1.5 g, approx. 0.5 mmole), 140 mg p-nitrophenol (1 mmole) and 65 mg dimethylaminopyridine (DMAP) (0.525 mmole) were dissolved in 30 ml of dry methylene chloride. To the resulting solution was added dicyclophexylcarbodiimide (DCC) (120 mg, 0.575 mmole) in 5 ml of dry methylene chloride. The solution was stirred under nitrogen overnight and the solvent was removed by rotary evaporation. The resulting syrup was redissolved in 10 ml of dry toluene and the insoluble solid was removed by filtration. Then the solution was precipitated into 100 ml of dry ethyl ether. The product was reprecipitated with ethyl ether, then collected by filtration and dried in vacuo. Yield 1.425 g (95%). 1 H NMR (DMSO-d 6 ) : δ3.5 (br m, PEG), 5.01 (s, PEGCOOC H 2 COONP), 2.69 (t, PEGOC H 2 CH 2 COO (PA)), 8.35 & 7.48 (d&d, H a & H b in NP, 4H).
Example 5
Preparation of CH 3 O-PEG-O—(CH 2 ) n —COO—CH(CH 3 )CH 2 —COONHS (n=1: mPEG-CM—HBA—NHS and n=2: mPEG-PA—HBA—NHS
Reactions
CH 3 O-PEG-O—(CH 2 ) n —COOH 3000 (3.0 g, 1 mmole) was azeotropically dried with 60 ml of toluene under N 2 . After two hours, the solution was slowly cooled to room temperature. To the resulting solution was added thionyl chloride solution (3 ml, 6 mmole) in CH 2 CL 2 , and the solution was stirred overnight. The solvent was condensed by rotary evaporation and the syrup was dried in vacuo for about four hours over P 2 O 5 powder. 3-hydroxybutyric acid (0.30 g, 2.7 mmole) was azeotropically dried with 70 ml of 1,4-dioxane on a rotary evaporator. The distillation was stopped when approximately 20 ml of solution remained. It was then slowly cooled to room temperature under N 2 , and the solution was added to the dried PEG acyl chloride. After the PEG was dissolved, 0.6 ml of dry triethylamine was injected to the system (precipitate formed immediately) and the solution was stirred overnight. The salt was removed by filtration and the filtrate was condensed on a rotary evaporator at 55° C. and dried in vacuo. The crude product was then dissolved in 100 ml of distilled water and the pH of the solution was adjusted to 3.0. The aqueous phase was extracted three times with a total of 80 ml of methylene chloride. The organic phase was dried over sodium sulfate, filtered to remove salt, condensed on a rotary evaporator, and added to 100 ml of ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 2.76 g (92%). 1 H NMR (DMSO-d 6 ): δ3.5 (br m, PEG), 2.54 (d, PEGCOOCH(CH 3 )C H 2 COOH), 5.1 (h, PEGCOOC H (CH 3 )CH 2 COOH), 1.2 (d, PEG-COOCH(C H 3 )CH 2 COOH), 2.54 (t, PEGOCH 2 C H 2 COO (PA)), 4.055 (s, PEGOC H 2 COO (CM)).
mPEG-ester butyric acid NHS ester (CM—HBA—NHS or PA—HBA—NHS): mPEG-ester butyric acid 3000 (1 g, approx., 0.33 mmole, CM—HBA—COOH or PA—HBA—COOH) and 42 mg N-hydroxysuccinimide (NHS) (0.3 mmole) was dissolved in 30 ml of dry methylene chloride. To this solution was added dicyclohexylcarbodiimide (DCC) 80 mg, 0.38 mmole) in 5 ml of dry methylene chloride. The solution was stirred under nitrogen overnight and the solvent removed by rotary evaporation. The residual syrup was redissolved in 10 ml of dry toluene and the insoluble solid was removed by filtration. The solution was then precipitated into 100 ml of dry ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 0.94 g (94%) 1 H NMR(DMSO-d 6 ): δ3.5 (br m PEG), 3.0-3.2 (m, COOCH(CH 3 )C H 2 COONHS), 5.26 (h, COOC H (CH 3 )CH 2 —COONHS), 1.3 (d, COOCH(C H 3 )CH 2 COONHS), 2.54 (t, OCH 2 C H 2 COO (PA)), 4.1 (s, OC H 2 COO (CM)), 2.81 (s, NHS).
Example 6
Determination of Hydrolytic Half-lives of the Ester Linkages
Reactions
Preparation of CH 3 O-PEG-O—(CH 2 ) n —COO—CH 2 —CONH-PEG-OCH 3 : CH 3 O-PEG-O—(CH 2 ) n —COO—CH 2 —COOH 3000 (0.5 g), 1 equiv. of mPEG-NH 2 2000 and 1 equiv. of 1-hydroxybenzotriazole (HOBT) was dissolved in 50 ml of methylene chloride. To this solution was added one equivalent of dicyclohexylcarbodiimide (DCC) and the solution was stirred at room temperature overnight. The solvent was partially evaporated, the insoluble salt was filtered, and the filtrate was added into a large excess of ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield: 0.8 g (95%). 1 H MNR (DMSO-d 6 ): δ3.5 (br m, PEG), 2.34 (t, —CONHC H 2 CH 2 O-PEG-).
Determination of hydrolytic half-lives of PEG ester conjugates with PEG amine: The conjugates from the above step and 20 wt % PEG 20,000 (as internal standard) were dissolved in a buffer solution. Then the concentration of the conjugate (C) and its hydrolysis product were monitored by HPLC-GPC (Ultrahydrogel 250 column, 7.8×300 mm, Waters) at predetermined time. The hydrolytic half-lives were obtained from the slope of the natural logarithm of C at the time t minus C at infinite time versus time, assuming 1 st order kinetics.
TABLE 1
Hydrolysis Half-Lives
(days, unless noted otherwise) of the
Ester Linkages Formed Between 1 and mPEG Amine (±10%)
Double-Ester PEG Used
CM-GA
PA-GA
CM-HBA
PA-HBA
pH
7.0
7.0
8.1
7.0
8.1
7.0
8.1
23° C.
3.2
43
6.5
—
15
—
120
37° C.
14 h
7.6
—
14
—
112
—
50° C.
4 h
2.2
—
5
—
58
—
Example 7
Determination of Hydrolysis Half-lives of the Active Ester
Reactions
R=CH 2 or CH(CH 3 )CH 2 ;
L=leaving group such as succinimidyl or p-nitrophenyl group.
Determination of hydrolysis half-lives of PEG active ester: Measurements were conducted using a HP8452a UV-VIS spectrophotometer. In an experiment, 1 mg PEG active ester was dissolved in 3.0 ml of buffer solution and shaken promptly to obtain solution as soon as possible. Then the solution was transferred into an UV cuvette and the absorbance at 260 nm for NHS ester or at 402 nm for the p-nitrophenyl ester was followed as a function of time. The hydrolytic half life was determined from the first order kinetic plot (natural logarithm of final absorbance minus absorbance at the time t versus time).
TABLE 2
Hydrolysis Half-Lives of Succinimidyl Active Esters
(R = NHS) and p-nitrophenyl Active Esters (R = NP)
of PEG-ester Acids at pH 8.1 and Room Temperature
R
CM-GA-R
PA-GA-R
CM-HBA-R
PA-HBA-R
NHS
11 s
11 s
12 min
12 min
NP
7 min
7 min
—
—
Example 8
Monitoring Hydrolytic Release of the PEG from Its Protein Conjugate by MALDI-TOF Mass Spectrometry
Modification of subtilisin with the PEG: To a subtilisin solution (1 ml, 2 mg/ml in 0.2M boric buffer pH 8.0) was added 15 mg mPEG-CM—HBA—NHS 3000. The solution was placed in an automatic shaker at room temperature. At predetermined time periods, 50 μl of the solution was removed and preserved in a refrigerator for MALDI-TOF MS measurement.
MALDI spectra was measured on a PerSeptive Biosystems' Voyager linear time-of-flight instrument. Briefly, a nitrogen laser lamda=337 nm, 10 ns pulse width) was used to generate ions which were extracted with a potential of 30 kV. Ions drifted through a 1.3 m drift tube and were monitored in positive ion mode.
Protein samples were dissolved in deionized H 2 O or 50 mM NaCl solution to a concentration of approximately 10 pmol/μl. The matrix, 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid), was dissolved in a 80:20 by volume ratio of acetonitrile to deionized water at a concentration of 10 mg/ml. 1 μl of the solution was deposited on the sample plate and then mixed with 1 μl of matrix solution. The sample was allowed to crystallize by solvent evaporation under ambient conditions. MALDI-MS spectra of the molecular weight distribution of the mPEG-HBA and subtilisin conjugate are shown in FIGS. 1 through 3 for different times after preparation. FIG. 1 is 1 day. FIG. 2 is 8 days. FIG. 3 is 14 days.
Example 9
Preparation of
Reactions
CH 3 O-PEG-O—CH 2 —COOH 5000 (3.0 g, 0.6 mmole), 2-(2-pyridyldithio)ethanol (342 mg, 1.5 mmole), DMAP (180 mg, 1.44 mmole) and HOBT (93 mg, 0.61 mmole) were dissolved in 60 ml of dichloromethane. To this solution was added DCC (138 mg, 0.66 mmole) in 5 ml of dichloromethane. The solution was stirred at room temperature under N 2 overnight. The solvent was removed by rotary evaporation and 15 ml of toluene was added to the residue. After all PEG dissolved, the solution was filtered to remove dicyclohexyl urea. To the solution was added 45 ml of methylene chloride and the solution was washed with sodium acetate buffer (0.1M, pH 5.0) which contained 10% sodium chloride. The organic phase was dried over anhydrous sodium sulfate, filtered to remove salt, condensed on a rotary evaporator, and precipitated into 100 ml of ethyl ether. The product was collected by filtration and dried in vacuo. Yield 2.85 g (95%). 1 H NMR (DMSO-d 6 ): δ3.5 (br m, PEG), 4.11 (s, PEGOC H 2 COO—), 4.30 (t, COOC H 2 CH 2 SS—) 7.29 (t, one aromatic proton), 7.77 (t+d, two aromatic protons), 8.46 (d, one aromatic proton).
Example 10
Determination of Hydrolysis Half-Lives of the Ester Linkage
Reactions:
mPEG-CM—SSP and 20% PEG 20,000 (wt) (as internal standard) were dissolved in 10 mM phosphate buffer (pH 7.2) and a series of ampoules were sealed each containing about 0.25 ml of above solution. The ampoules were stored as two groups, one group at room temperature and the other at 37° C. At each measurement, one ampoule in each group was opened and the solution was analyzed. The concentration of mPEG-CM—SSP and its hydrolysis product were determined by HPLC-GPC (Ultrahydrogel 250 column, Waters; 5 mM phosphate bufer pH 7.2 as mobile phase). The hydrolytic half-life was obtained from the slope of the natural logarithm of C at the time t minus C at infinite time versus time, assuming 1st order kinetics.
TABLE 3
Hydrolytic Half-Lives (Days) of the
Ester in mPeg-CM-SSP (±10%)
pH 5.5
pH 7.0
Room temperature
107
18
37° C.
20
2.9
Example 11
Preparation of CH 3 O-PEG-O(CH 2 )n-CO 2 -PEG-OCOONHS
Reactions
(a) Preparation of CH 3 O-PEG-OCH 2 CH 2 CO 2 -PEG-OBz
In a 100 ml round-bottom flask, a solution of CH 3 O-PEG-O—(CH 2 ) n —CO 2 H (MW=2000, 2 g, 1 mmol) was dissolved in toluene and azeotropically dried for two hours. After slowly cooling to room temperature, the solution was added to thionyl chloride (3 ml, 6 mmole) in methylene chloride and then stirred under N 2 overnight. The solvent was then removed by rotary evaporation and the residual syrup was dried in vacuo for about four hours over P 2 O 5 powder. To the solid was added 5 ml of anhydrous methylene chloride and A solution (20 ml)(of azeotropically dried BzO-PEG-OH (MW=3400, 2.04 g, 0.60 mmol) in toluene To the resulting solution was added 0.6 ml of freshly distilled triethylamine and the solution was stirred overnight. The triethylamine salt was removed by filtration and the crude product was precipitated with ethyl ether and collected by filtration. The mixture was then purified by ion-exchange chromatography (DEAE sepharose fast flow column, Pharmacia). Pure CH 3 O-PEG-O—(CH 2 ) n —CO 2 -PEG-OBz was obtained. Yield: 2.6 g (80%). NMR (DMSO-d 6 ): δ3.5 (br m, PEG), 2.55 (t, —OCH 2 C H 2 COOPEG-), 4.14 (s, -PEGOC H 2 COOPEG-), 4.13 (t, -PEGOCH 2 CH 2 —COOC H 2 CH 2 OPEG-), 4.18 (t, -PEGOCH 2 —COOC H 2 CH 2 OPEG), 4.49 (s, -PEG-O—C H 2 —C 6 H 5 ), 7.33 (s+com, -PEG-O—CH 2 —C 6 H 5 ).
(b) Preparation of CH 3 O-PEG-O—(CH 2 ) n —CO 2 -PEG-OH
A solution of 2 g of CH 3 O-PEG-O—(CH 2 ) n —CO 2 -PEG-OBz in 1,4-dioxane was hydrogenolyzed with H 2 (2 atm) on 1 gram Pd/C (10%) overnight. The catalyst was removed by filtration, the solvent was condensed under vacuum and the solution was added to ethyl ether. The product was collected by filtration and dried under vacuum at room temperature to yield: 1.5 g (75%) of CH 3 O-PEG-O—(CH 2 ) n —CO 2 -PEG-OH. NMR (DMSO-d6): δ3.5 (br m, PEG), 2.55 (t,—OCH 2 C H 2 COOPEG-), 4.14 (s, -PEG-OC H 2 COOPEG-), 4.13(t, -PEGOCH 2 CH 2 COOC H 2 CH 2 OPEG-), 4.18 (t, -PEGOCH 2 —COOC H 2 CH 2 OPEG).
(c) Preparation of CH 3 O-PEG-O—(CH 2 ) n —CO 2 -PEG-OCOONHS
CH 3 O-PEG-O—(CH 2 ) n —CO 2 -PEG-OH 5400 (1.25 g, 0.23 mmole) was azeotropically distilled with 100 ml acetronitrile and then cooled to room temperature. To it were added disuccinimidyl carbonate (245 milligram, 0.92 mmole) and 0.1 ml of pyridine, and the solution was stirred at room temperature overnight. The solvent was then removed under vacuum, and the resulting solid was dissolved in 35 ml of dry methylene chloride. The insoluble solid was removed by filtration, and the filtrate was washed with pH 4.5 sodium chloride saturated acetate buffer. The organic phase was dried over anhydrous sodium sulfate, filtered, condensed by rotary evaporation, and precipitated into ethyl ether. The product was collected by filtration and dried in vacuo. Yield: 1.20 g (96%), 100% substitution of succimidyl carbonate and no reagent left. NMR (DMSO-d 6 ): δ3.5 (br m, PEG), 2.55 (t, —OCH 2 C H 2 COOPEG-), 4.14 (s, -PEG-OC H 2 COOPEG-), 4.13 (t, -PEGOCH 2 CH 2 COOC H 2 CH 2 OPEG-), 4.18 (t, -PEGOCH 2 —COOC H 2 CH 2 OPEG), 4.45 (t, -PEGO-CH 2 C H 2 OCONHS), 2.81 [s, NHS].
The invention has been described in particular exemplified embodiments. However, the foregoing description is not intended to limit the invention to the exemplfied embodiments, and the skilled artisan should recognize that variations can be mad within the scope and spirit of the invention as described in the foregoing specification. On the contrary, the invention includes all alternatives, modifications, and equivalents that may be included within the true spirit and scope of the invention as defined by the appended claims. | PEG and related polymer derivatives having weak, hydrolytically unstable linkages near the reactive end of the polymer are provided for conjugation to drugs, including proteins, enzymes, small molecules, and others. These derivatives provide a sufficient circulation period for a drug-PEG conjugate and then for hydrolytic breakdown of the conjugate and release of the bound molecule. In some cases, drugs that previously had reduced activity when permanently coupled to PEG can have therapeutically suitable activity when coupled to a degradable PEG in accordance with the invention. The PEG of the invention can be used to impart water solubility, size, slow rate of kidney clearance, and reduced immunogenicity to the conjugate. Controlled hydrolytic release of the bound molecule in the aqueous environment can then enhance the drug delivery system. | 2 |
This Nonprovisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 03079005.9 filed in Europe on Dec. 19, 2003, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a printer comprising a printing unit for printing on a receiving medium of a predetermined type, a plurality of feeders for holding receiving media, and means for establishing the type of receiving medium held by each of the feeders.
The present invention furthermore relates to a method for printing a receiving medium of a predetermined type using a printer having a printing unit and a plurality of feeders for holding the receiving media, the method including the establishment of the type of receiving medium to be held by each of the said feeders.
The printer, which is known from U.S. Pat. No. 4,885,613 includes a plurality of feeders with the same receiving medium in the form of a roll or sheets wherein the feeder is selected from the largest amount of recording medium remaining therein. In such a printer, a nearly empty feeder will only be fully emptied if the other feeders holding the same type of receiving medium have been also emptied. Thus, a printer will almost never contain an empty feeder in which another type of receiving medium, for example receiving sheets having another format, another color or another thickness can be inserted. The feeders will be used successively since after using one feeder, the amount of receiving sheets remaining therein will be less than the amount of receiving sheets in another feeder so that said other feeder with the larger amount of receiving sheets will be selected by the control unit. For example, in the case where there are four feeders containing the same type of receiving sheets, all four feeders will be used successively and become empty at almost the same moment. At that moment the operator needs to replenish all feeders at the same time. By using the feeders successively, many feeder changes, involving relatively elaborate operator handling, will occur.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a printer whereby the feeders will be used in a more optimised manner.
This object is achieved by utilizing a printer containing a means for determining for at least two feeders holding a predetermined type of receiving material, the amount of receiving medium which can be added to each of these feeders up to a predetermined maximum amount, and means for selecting the feeder to which the largest amount of receiving medium can be added for feeding the receiving medium to the printing unit.
By utilizing receiving sheets from the feeder to which the largest amount of receiving medium can be added, this feeder will be fully emptied before another feeder will be selected. In this manner, only a relatively small number of feeder changes will occur. Since the feeder which is being selected will be fully emptied before another feeder will be selected, the feeder will become available for using another type of receiving medium, if necessary. Furthermore, if an operator wants to replenish the feeders, he can add a relatively large amount of receiving sheets to the feeder which is at that moment being selected by the control unit as the feeder for feeding receiving sheets to the printing unit.
The printer, according to the present invention, gives the operator substantial freedom to decide when he wants to replenish the feeders and which feeders he wants to replenish.
In one embodiment of the printer according to the present invention, the feeder closest to the printing unit is selected, for example by a control unit, in the case where there are more feeders to which the same largest amount of receiving medium can be added. By selecting the feeder closest to the printing unit, the printer will be able to print relatively fast on the receiving medium. In the case where there are more feeders at the same distance from the printing unit, the lowest feeder is preferably selected.
In another embodiment of the printer according to the present invention, the feeder which has the smallest amount of receiving medium therein is selected, for example by the control unit, in the case where there are more feeders having the same largest amount of receiving medium which can be added. By utilizing feeders having different predetermined maximum amounts, the feeder which has the smallest amount of receiving medium left therein will be selected. This feeder will thus be emptied relatively quickly so that it becomes available for other types of receiving medium.
In yet another embodiment of the printer according to the present invention, the printer includes a level detector means for determining the amount of receiving medium available in the feeders, and also includes subtraction means for subtracting the available amount from a predetermined maximum amount to obtain the amount of receiving medium which can be added to each feeder. In this manner the amount of receiving medium that can be added to each feeder can be determined in a relatively easy manner.
In a further embodiment of the printer according to the present invention, the printer contains means for measuring the distance between a first level at which the feeder is filled with receiving medium up to the predetermined maximum amount and a second level up to which said feeder is actually filled with receiving medium. By measuring this distance, the amount of receiving medium which can be added can be determined relatively easily.
The amount of receiving medium which can be added to each feeder can be determined relatively accurately or relatively rough in which latter case, there will be established a kind of threshold. For example, the amount of sheets can be determined by using increments equal to 100. In the latter case for example, the amount of sheets that can be added is determined as zero sheets, 100–200 sheets, 200–300 sheets etc.
The present invention also relates to a method for printing a receiving medium of a predetermined type using a printer having a printing unit and a plurality of feeders for holding receiving media, the method including the steps of establishing the type of receiving medium held by each of the feeders, and, if the predetermined type of receiving material is held by at least two feeders, determining the amount of receiving medium which can be added to each of the said at least two feeders up to a predetermined maximum amount, and selecting the feeder to which the largest amount of receiving medium can be added for feeding the receiving sheet to the printing unit. By following this method, a once chosen feeder will be fully emptied before another feeder will be selected unless another empty feeder will be refilled with a very small amount of paper, in the case of which this feeder will be selected. In this manner feeders will be emptied relatively quickly and become available for other types of receiving media. Furthermore an operator will have a relatively large freedom by replenishing the feeders.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will further be explained with reference to the drawings wherein,
FIG. 1 schematically shows a set of feeders of a printer according to the present invention;
FIG. 2 shows a printer according to the present invention; and
FIG. 3 schematically shows a feeder comprising sensing means according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a part of a known printer containing a printing unit (not shown), a plurality of feeders 1 , 2 , 3 for feeding receiving sheets 4 to the printing unit and a control unit (not shown) for controlling the printing process. The printer may include a large number of feeders of which only three feeders are being shown. In the three feeders, the same type of receiving sheets, for example sheets with an A4-format, 80 grams, and white color are available. In the present embodiment, this is established automatically by the printer by using art known sensing means for sensing the type of receiving material. In another embodiment, the type of receiving material is programmed by the operator and stored in a memory, for example the memory of a control unit of the printer. In feeder 1 a predetermined maximum amount of receiving sheets 4 is MAX 1 , the predetermined maximum amount of feeder 2 is MAX 2 and the predetermined maximum amount of feeder 3 is MAX 3 . The maximum amount for feeders 1 , 2 is the same so that MAX 1 =MAX 2 , whereby MAX 1 is for example 1000 sheets. The predetermined maximum amount MAX 3 of feeder 3 is larger than the maximum amounts MAX 1 , MAX 2 and is for example 3000 sheets.
FIG. 2 shows a printer 5 utilizing the three feeders as shown in FIG. 1 , a printing unit 6 , a control unit 7 for controlling the printer 5 as well as a tray 8 in which sheets on which information is printed by printing unit 6 can be stored. Although depicted as one single unit 7 , it is clear that the control unit may also consist of several subunits distributed over the printer. Other parts of the printing unit 6 are the imaging belt 20 , charging station 21 , printhead 22 with control unit 23 , developing station 24 , intermediate transfer belt 25 and transfer nip 26 . Such a printer is described in greater detail in European patent application EP 0 599 374 the subject matter of which is hereby incorporated by reference.
The printer 5 includes sensing means (not shown) for each feeder 1 , 2 , 3 provided with level detector means for determining the amount of receiving sheets Δ 1 , Δ 2 , Δ 3 available in each feeder 1 , 2 , 3 . The sensing means furthermore comprise subtracting means for subtracting the available amount Δ 1 , Δ 2 , Δ 3 from the predetermined maximum amount MAX 1 , MAX 2 , MAX 3 to obtain the amount ADD 1 , ADD 2 , ADD 3 of receiving sheets which can be added to each feeder 1 , 2 , 3 .
The feeder 1 comprises, for example, an amount Δ 1 of 300 receiving sheets 4 so that ADD 1 is 1000−300=700. In feeder 2 the available amount Δ 2 is 600 so that ADD 2 is 1000−600=400. In feeder 3 the available amount Δ 3 is 1600 so that ADD 3 is 3000−1600=1400. It is not absolutely necessary to determine the exact amount of receiving sheets 4 but a rough estimation rounded up to hundreds might work as well.
By using the control unit it can now be determined to which feeder the largest amount of receiving sheets can be added. By the example given above, the feeder 3 will be selected since ADD 3 (1400) is larger than ADD 2 (400) and ADD 1 (700). By selecting feeder 3 , several printing processes can be done until feeder 3 is fully emptied. By the control unit it will then be decided to use feeder 1 since ADD 1 with 700 sheets is larger than ADD 2 with 400 sheets. An operator can be informed of the available amount Δ 1 , Δ 2 , Δ 3 and/or the amount ADD 1 , ADD 2 , ADD 3 of receiving sheets which can be added to each feeder, by means of a display (not shown) or by an indicator means (not shown) on each feeder 1 , 2 , 3 or by opening each feeder 1 , 2 , 3 . The operator can then replenish the feeder 3 with a relatively large amount of receiving sheets. After replenishing the empty feeder 3 , the control unit will continue by emptying feeder 1 . After feeder 1 is emptied, the control unit will select feeder 2 since after emptying feeder 1 and replenishing feeder 3 up to the maximum amount MAX 3 , feeder 2 has the largest amount ADD 2 of receiving sheets which can be added. The operator can replenish feeder 1 before feeder 2 is fully emptied or can replenish both feeders 1 and 2 after the feeder 2 is also emptied. Preferably a feeder 1 , 2 , 3 is not replenished while a feeder 1 , 2 , 3 is being used as a feeder for feeding a receiving sheet to the printing unit, to prevent disruption of the printing process. If a feeder is opened, another feeder will be selected temporarily.
Instead of determining the amount Δ 1 , Δ 2 , Δ 3 , it is also possible to provide the printer with sensing means for measuring between a first level LM 1 , LM 2 , LM 3 at which the feeder 1 , 2 , 3 is filled with receiving sheets 4 up to the predetermined maximum amount MAX 1 , MAX 2 , MAX 3 and a second level L 1 , L 2 , L 3 up to which said feeder 1 , 2 , 3 is actually filled with receiving sheet 4 . The distance D 1 , D 2 , D 3 is a measure of the amount of receiving sheets which can be added, whereby the largest distance, in this example D 3 , corresponds with the largest amount of receiving sheets which can be added.
FIG. 3 shows another kind of feeder 9 in which the stack of receiving sheets 4 is located on a platform 10 which is movable under a spring force in an upward direction until the upper sheet 4 is located against a transport roller 11 . The level L 4 of the platform 10 is determined by means of the control unit 7 in which also the maximum level LM 4 of the platform 10 is also being stored. The difference between the maximum level LM 4 and L 4 provides the control unit 7 with information about the actual amount of receiving sheets in the feeder 9 while the level L 4 is a direct measure of the amount of receiving sheets which can be added to the feeder 9 .
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | A printer for printing on a receiving medium of a predetermined type, including a plurality of feeders for holding receiving media and a control unit, wherein the control unit contains determining means for determining that at least two feeders of the said plurality of feeders hold receiving medium of the predetermined type, means for determining the amount of receiving medium which can be added to each of the two feeders up to a predetermined maximum amount for these feeders, and means for selecting the feeder to which the largest amount receiving medium can be added for feeding a receiving medium to the printing unit. | 6 |
TECHNICAL FIELD
The general area of the aspects of the present disclosure are directed to human computer interfaces, augmented reality, wearable and mobile devices. The aspects of the present disclosure generally relates to a system and a method for touch-free, natural hand-gesture based human to device interface.
BACKGROUND
Computing and communication devices including mobile phones have changed substantially in the last few decades. The emergence of personal computing in the later 1970s including both personal software (productivity applications, such as text editors and spreadsheets, and interactive computer games) and personal computer platforms (operating systems, programming languages, and hardware), made everyone in the world a potential computer user. Human interaction with computers has come a long way from keyboard, mouse to touch screen and to hand gesture(s).
Using hand gestures has always been a powerful human-to-human communication modality. The expressiveness of hand gestures also allows for the altering of perceptions inhuman-computer interaction. Gesture recognition allows users to perceive their bodies as an input mechanism, without having to rely on the limited input capabilities of the devices. Possible applications of gesture recognition as ubiquitous input on a mobile phone include interacting with large public displays or TVs (without requiring a separate workstation) as well as personal gaming with LCD video glasses.
The prior art relates to the way a human could interact with a computer (such as a wearable or mobile device) using hands. Hand gestures are a natural way to communicate, and in fact some information can be passed via hand signs faster and simpler than any other way. As an example, major auction houses use hand gesture for bidding on multi-million auctions. Thus it seems natural that, as you see the information in front of you, you can use it with your hands.
Many gesture recognition algorithms have been implemented such as algorithms based on the color of the hand and using the HSV: Dadgostar, Farhad, and Abdolhossein Sarrafzadeh. “An adaptive real-time skin detector based on Hue thresholding: A comparison on two motion tracking methods.” Pattern Recognition Letters 27, no. 12 (2006): 1342-1352. Mittal, Arpit, Andrew Zisserman, and Philip Ton. “Hand detection using multiple proposals.” (2011).
Others have identified also ways to extract hands from the background using the hull and convexity defects with a static camera (like on a robot) recognition of the hands is possible: Pulkit, Kathuria, and Yoshitaka Atsuo. “Hand Gesture Recognition by using Logical Heuristics.” HCI, 2012, no. 25 (2012): 1-7. Wang, Chieh-Chih, and Ko-Chih Wang. “Hand Posture recognition using Adaboost with SIFT for human robot interaction.” In Recent progress in robotics: viable robotic service to human, pp. 317-329. Springer Berlin Heidelberg, 2008.
Another method is by using the facial detection (which is not useful when camera sits on user's body, like on the shoulder, top of the head, pocket or glasses): Dardas, Nasser H., and Nicolas D. Georganas. “Real-time hand gesture detection and recognition using bag-of-features and support vector machine techniques.” Instrumentation and Measurement, IEEE Transactions on 60, no. 11 (2011): 3592-3607.
Conventionally, commercial systems such as Microsoft Kinect™ use stereo-vision combined with infrared light. This means that a light emitting diode (“LED”) emits invisible light on specific frequency, and two cameras, a small distance from each other, capture the image at that exact light frequency. As the object closer to the camera produces or reflects significantly more light than those objects behind the object closest to the camera, it is easy to extract foreground images or objects from background images or objects and hence recognize the hands. In addition, two cameras capture two images, overlying them to correctly give a precise distance of the each point of an object providing a 3D picture. This system has superior recognition but it has drawbacks such as extra energy usage, bigger size, and more expensive. Another approach seen in some systems is to use special sensors (such as proximity, movement or still background etc.) that can capture movement and translate it into commands. These sensors can be on the user, inside the clothes, or in the proximity of the user, for instance on a desk near the user. These systems are complex to set up and expensive in terms of cost of materials as well as the energy usage.
Hence, there exists a need for a system and method that detects where the user's hands are, interprets the hand gestures in real-time, and is inexpensive. Also, there is a need for a system that overcomes user environmental variations such as exposure, lighting, background color, back-light, different user hands, skin color or wearing of gloves.
BRIEF SUMMARY
The aspects of the present disclosure provides a system and method for recognition of hand gesture in or by computing devices.
In one embodiment, the system includes one camera that can view a user's hands and a feedback interface that can provide feedback to the user, such as a visual display or other forms of acoustic or vibration feedback. The system is configured to recognize a hand of a user by identifying a first gesture, which in one embodiment is a pre-defined gesture and further collect visual information related to the hand identified on the basis of the first predefined gesture. Optionally, the system can use the visual information to extract a second (and all other gestures after the second) gesture from the video/image captured by the camera, and finally interpret the second gesture to enable user input. The system enables gesture recognition in various light conditions and can be operated by various user hands including the ones wearing gloves.
The system of the disclosed embodiments may optionally include a wearable camera, a head mounted camera or display, a near-the-eye display, or any other tactile or acoustic forms of feedback.
The system may optionally include a display, a microphone, or a speaker that allows a user to access information and interact with an information system while driving, operating on a patient, cooking or anything else that involves human computer interaction.
Optionally, the system is connected to Internet, and can send and receive information from anywhere.
In another aspect, embodiments of the present disclosure provide a method for recognition of hand gesture in or by computing devices.
In accordance with yet another embodiment of the present disclosure, the system is configured to work with devices which have at least one camera that can view a user's hands and a feedback interface that provides feedback to the user, such as a visual display or other forms of acoustic or vibration feedback. The device may or may not be connected to Internet. Typical examples of the devices include, although are not limited to, smart phones, Mobile Internet Devices (MID), wireless-enabled tablet computers, Ultra-Mobile Personal Computers (UMPC), phablets, wearable computer, tablet computers, Personal Digital Assistants (PDA), web pads and cellular phones. Other non-limiting examples include a car with centrally mounted camera and display on the windshield, or a house with a system of cameras and a voice feedback, or a feedback on the TV.
Additional aspects, advantages, and features of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments.
It will be appreciated that features of the disclosure are susceptible to being combined in various combinations or further improvements without departing from the scope of the disclosure and this application.
DESCRIPTION OF THE DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, similar elements have been indicated by identical numbers.
FIG. 1 shows a high level use case of a system incorporating aspects of the present disclosure.
FIG. 2 illustrates example of use case of the one embodiment of the system of the present disclosure with head mounted display.
FIG. 3 presents an example of a hand gesture to initiate search command.
FIG. 4 illustrates gestures designated for letters A, B, C, D, E, F, G, H, I, J, K and L).
FIGS. 5A and 5B outlines steps performed by an embodiment of the system incorporating aspects of the present disclosure in a use case.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present disclosure provides a system and method for recognizing the hand of the user in any conditions. The method relies on an initial gesture, called the opening gesture, after which the hands of the user are registered. Generally, the initial gesture is predefined. The information extracted from the initial gesture can also be used later. In embodiment, a registration or learning process is used to predefine movements to extract features. In such a learning process, the system can be provided with a set of predefined features that can then be compared to movements in order to extract those features, in a feature extraction process. Different feature extraction sets, which can include images, shapes and movements for example, can be defined in the registration or learning process.
The term “feature” as is used herein, generally refers to a piece of information relevant to solving a computational task involved in recognition of an object or shape of an object. More specifically, features can refer to the result of a general neighborhood operation (feature extractor or feature detector) applied to the image, specific structures in the image itself (edges, corners, curvature, etc. up to complex structures such as objects). Other examples of features are related to motion vectors in images, to shapes defined by contours or to properties of such a region (like mass, convexity, etc.).
In one embodiment, an opening gesture can be the open hand. Once the opening hand as the initial gesture is recognized, the system is then able to extract other gestures and track the hands. The opening gesture is also called the registration gesture or calibration gesture. The registration of the hands comprises a method in which the hand shape is known to the system, such as through the initial learning or registration process. Once the opening gesture, also referred to as an initial gesture or reference shape, is recognized, which might also be referred to as being detected or identified, the system is then able to extract one or more other shapes provided by, or detected in the camera image and compare them with the reference shape. Such other shape(s) should be recognizable and unique as such that it should allow the system to extract many features and should also be invariant between other possible shapes (invariant to rotation, or mirroring).
In one embodiment, the detection and recognition of a gesture can result in a command being issued. A “command” as that term is generally used herein, refers to a function or instruction that can be executed by a computing device. In one embodiment, the command can result in an action being performed by the computing device. The detection, interpretation or recognition of a gesture can result in one or more commands.
In one embodiment, the command(s) can be generated as a function or result of a single gesture (hand shaped in certain way), or a series of gestures (movements of hands while they are in certain shape, or while they are dynamically changing shape, such as the “come here” gesture, or a “no-no” gesture), or a series of relative movements with two hands, where one hand can give a reference point, while the other can define a relative movement. This method can be used to emulate a mouse movement as well.
Referring now to the drawings, particularly by their reference numbers, FIG. 1 shows a high level use case of one embodiment of a system incorporating aspects of the present disclosure. A user 102 has a portable or mobile computing device such as a smart phone 100 in his hand 104 . The aspects of the disclosed embodiments are generally directed to portable and wearable electronic devices. The device 100 is positioned in the hand 104 in a way that the user can see a display 1000 view captured by a camera 1002 of the device 100 . The system optionally performs image analysis in a central processing unit 1006 of the computing device 100 or other calculation unit of the device 100 . The central processing unit 1006 can generally comprise a memory and a processor. The central processing unit 1006 , or processor, can generally be configured to execute non-transitory computer or machine readable instructions, for carrying out the processes generally described herein. The system may also include a software product installed in a storage 1004 of the computing device 100 , which can include removable and non-removable storage or memory. The software product can include machine readable instructions that when executed by the central processing unit 106 , causes the central processing unit 1006 to execute or perform the steps needed to identify and recognize gestures made by user 102 with other hand 106 . Gestures can include, for example, movements/poses made with palm 1060 of the hand 106 . It is noted that while reference is made to the palm 1060 of the hand 106 , the aspects of the disclosed embodiments are not so limited and can include other features of the hand 106 , such as for example fingers. The software product can be standalone product or it can be part of the operating system of the system or central processing unit 1006 to enable other software products to utilize gesture recognition or it can be provided as library component for software developers to include gesture recognition capabilities. In preferred setup the software product is part of the operating system platform and it can be used/linked/complied as part of other software products. Based on alternative embodiments the device 100 may use a communication module to send some or all captured video/still images to an external computing environment such as server system 108 with databases 110 for processing and determining the type of gestures.
In one embodiment, the system 100 uses a single camera that captures the images of one or more of the user's hands, or aspects of one or more of the user's hands. In alternate embodiments, it is contemplated that any suitable number of camera, or other image capturing devices can be used, such as two or more cameras. The hands of the user 104 can be covered with gloves. The camera 1004 can be any basic image capturing device, such as a color or digital camera. The system 100 can give feedback to the user in any form visual, tactile, audio, etc.
Referring to FIG. 2 , an example of use case of a system incorporating aspects of the present disclosure includes a computing device with a head mounted display 200 which can be worn by the user. The head mount display system 200 can include camera 2002 and display 2004 . The display 2004 can be a semi-transparent display enabling the user to see thru the display 2004 and enabling the computing device to add information in the display 2004 . This enables providing or making use of augmented reality. The head mount display system 200 can include processor, memory, and/or communication interface. The display system 200 can be configured to perform steps of gesture recognition a stand-alone unit or it can send some of the information to external system 108 , 110 such as smart phone 202 in the pocket of the user or to the server directly or via the smart phone. The head mount display device 200 shown in FIG. 2 enables the user to use both hands 104 and 106 to make gestures in an easy way since there is no need to hold the device 200 . Palms 1040 and 1060 of the hands 104 and 106 are typically used to make gestures.
As the term is used herein, “gestures” generally refers to movement of one or two or more hand(s) and/or palm of the hand or other part of the hand, such as the fingers. This can include the position of the hand, or any part thereof, in respect to captured video or environment. The pose of the hand/palm of the hand such as how fingers are posed, how many fingers are shown, how fingers are moving in respect to each other, or how the fingers are positioned in respect to each other finger. Additionally, gestures can refer to gestures used in sign language used by deaf people, for example.
In a non limiting example, FIG. 3 presents an example of a hand gesture that can be used to initiate a search command. The system 100 can then use the “hand anthropometry” ratios to classify the shape as an open hand. FIG. 4 illustrates gestures designated for letters A, B, C, D, E, F, G, H, I, J, K and L. These gesture codes can be used by the system 100 , together with other movements/poses made with palm 1060 of the hand 106 , as an input that can lead to the generation of one or several commands for the execution of an action or function. In alternate embodiments, it will be understood that any suitable gesture can be used to define one or more codes, which when detected and interpreted, will lead to the generation of a command.
Referring to FIGS. 5A and 5B outlines steps performed by a system incorporating aspects of the present disclosure in a use case. Once an image is captured, the system broadly performs two steps, a Search 500 and Match 510 . The search step 500 generally comprises the detection and recognition of the opening gesture. The match step 510 correlates the detected or identified gesture to a command that can be executed or performed by the system.
FIG. 5A outlines the search 500 step. In the search step 500 , with no prior data, a search or similar analysis is performed of the captured image(s) for a predefined activation shape 501 , also referred to herein as the initial or opening gesture. In one embodiment, the predefined shape is a template shape that is used by the system to trigger a calibration process. The predefined shape can be any predefined pose that the hand of the user can take. In one embodiment, the term “shape” can also include movement. In a non limiting example, the predefined shape to search in the captured image(s) is the shape of the open palm as referred in FIG. 3 of the present disclosure. In one embodiment, the system uses “hand anthropometry” ratios to classify the predefined shape as an open hand.
The system creates a shape tracker/filter 503 to identify and isolate or group, other objects in the captured image(s) or pictures. The objects can include anything else that is in the captured image(s). This can be done using color filters (called color blobs) or by means of motion vectors by tracking the objects that move or have been moved between frames, where the capture image includes more than one frame. The identified and isolated objects in the captured image(s) can be labeled. For example, groups of pixels that look similar can be grouped and called objects.
After the objects in the images have been labeled, the system examines the shape 504 of the labeled objects that are then used 505 against a search state that looks into the features of the objects and compares them to the known features of the predefined activation shape. The feature comparison 506 takes care of size variance, rotation, mirroring, and other variations in the 3D to 2D or rotation around all 3 axis. When the comparison concludes that the shape 504 is the predefined activation shape?, the process will store the values 508 (such as color, size etc) that lead to the positive result and use them to find the future shapes that the object (user's hand) will present. The search process can happen all the time (like in parallel with the matching). In one embodiment, the process continuously scans the image for a predefined activation shape until it detects 507 regardless of a previously detected one. Thus, even when a predefined activation shape is detected, the system continues to search for another predefined activation shape. This allows the system to adapt to colour or light variations, as well if the user decides to use gloves. The values of the past hits (matches) can also be used and combined in an adaptive manner so that they will give the best results 509 for tracking the future hands gestures. In one embodiment, common background objects can be removed in a filtering or other segregation process.
FIG. 5B outlines the Match step 510 . In one embodiment, the system identifies the gesture provided by the user's hands after the search of predefined shape 500 for the predefined activation shape is completed. In Match 510 the results 509 of the search process 500 are used. The results 509 generally comprise a set of initial features, such as left hand, right hand, color etc. The matching process includes a more detailed examination of the shape 513 since it is looking for many gestures. The system identifies tracker/filter values extract features by comparing the results 509 with predefined signs in the system. A few non limiting examples of hand gestures have been outlined in FIG. 4 of this disclosure which show hand gestures designated for letters A, B, C, D, E, F, G, H, I, J, K and L. The process can compare the shape of the hand gesture, such as left hand, right hand until a match or close match is found 515 . In this example, the features extracted from the image received from the camera are compared with the features defined as matching the desired shape. This process will result 516 with a gesture code that can be used by any information system computer, communication device, mobile phone, etc., as an input that can lead to an action command 517 . Examples of such action commands 517 can include, but are not limited to, opening a page, moving to a next item, answering a call, etc.
In an non limiting example enabled by the process outlined in FIGS. 5A & 5B , the use case involves a phone call. In this example, the user receives a call. The user starts by placing their hands in the position or pose of an activation gesture that enables the system to recognize the hands in the pre-defined activation gesture. In this example, the activation gesture is an open palm. In alternate embodiments, the activation gesture can be any suitable pre-defined hand gesture. When the activation gesture is recognized, in one embodiment, the system can provide feedback to the user of the recognition of the activation gesture. Examples of such feedback can include, but are not limited to a visual indication, audio indication or tactile indication.
Once the activation gesture has been made by the user and recognized, the user then moves or configures the hand to provide a “thumbs up” gesture, which in this particular example means that the user wants to answer the call. This can be called the “command” gesture. In one embodiment, the system can provide the user with a prompt to provide the command gesture. For example, one the activation gesture is recognized, the system indicates to the user to provide a command gesture. The prompt can be in the form of a visual, audible, or tactile prompt. For example, the user can receive feedback or a prompt from the phone, for example voice signal asking, once the activation gesture has been validated, “do you want to take the call?” As the user makes the thumbs up gesture, the system will detect the thumbs up gesture and match or otherwise validate the gesture. In one embodiment, a confirmation from the phone, such as “Call answered” can be heard.
As another example, if the user wants to call someone, the user can use a gesture to activate the phone. In one embodiment, a menu item or list can be displayed, or a voice can be used to read the menu list to the user, such as in a hands free environment. Any other tactile or audio feedback is contemplated within the scope of the disclosed embodiments. The menu list can include numbered function selections for example which will allow the user to activate one or more functions of the phone, such as a calling function. The user can select a menu item by using hand gestures that correspond to the menu item, like “number 1, number 2, etc.
In one embodiment, the commands can be context sensitive. For example, a second gesture in a first image context can be used to provide a first command. The same second gesture in a second image context can be used to provide a second command, different from the first. Thus, the same gesture can be used to generate different commands, depending upon the context of the preceding gesture.
In one embodiment, a context or setting of the second gesture is determined before the second gesture is matched with a command. For example, in one embodiment, the context can correspond to an application that is open when the activation gesture is detected. Thus, when the activation gesture is detected, the currently active application on the device is identified. The detected second gesture is then matched to commands corresponding to the active application.
In another non limiting example for using the system 100 , a user has a wearable video camera. The camera can be attached on clothes, head, eye-glasses, or even clipped in a way that the camera captures a view of the user hands such that the user himself would be able to look at them. The camera grabs or otherwise captures the images and sends them to the system. In one embodiment, where the images are or include colour, the system examines the colour images and groups the colors to form “color blobs”. With black and white or grayscale images, the system might group the images and objects based on the degrees of black and white. The system optionally examines the previous frames such that it determines movement of one or more objects within the images and uses that information. The system then examines the shape of the color blobs or the moved objects and searches the color blobs or moved objects for one that resembles closely a predefined shape, such as an open hand. Once the system identifies an object as the pre-defined shape in the image(s), the system uses information associated with the identified shape to track the color or the movement of the identified shape in the image so that the system recognizes the same object in the future frames. The system can also identify the background image(s) and remove the background image(s) from the tracking in future images. This allows the system to auto-calibrate itself each time the user shows or otherwise presents the predefined activation shape to the camera. Once an object in the image(s) is identified as the pre-defined activation shape, subsequently detected gestures in the images are considered or correlated to hand gestures that the system interprets as command input(s) that can be used to operate the system or activate functions of the system. Some of the exemplary gestures that can be used to operate the system are shown in FIGS. 4 and 5 .
In one embodiment, the aspects of the disclosed embodiments can be used to conserve or reduce power consumption of an electronic or computing device. In one embodiment, in computing device of the disclosed embodiments can be configured to run at two or more speeds. For example, in one embodiment, the computing device can be operating at a first, or low power and speed. When the activation gesture is detected, the hardware of the computing device can be configured to switch to a second, high power and faster operating speed. Thus, the aspects of the disclosed embodiments can be configured to increase the processor and clock speed of the computing device when the activation gesture is identified. This can allow the computing device to add or increase the use of resources for detecting the second gesture and executing any corresponding command that is identified.
As another example of the hardware optimization provided by the aspects of the disclosed embodiments, the algorithm described herein is split into two “stages”, one called “search 500 ” and the other one called “match 510 ”. In one embodiment, the search 500 can run the search utilizing less resources. In a hardware adaptation, the search part will use less CPU power, or only one CPU core or even lower frequency to save the resources until the pre-defined activation shape is recognized. When that happens, the match 510 process will be kick started and full resources of the computing device can be used. That way, the aspects of the disclosed embodiments are more power friendly to “wearable devices” where the devices need to operate continuously.
Embodiments of the present disclosure can include portable computing device such as mobile phones, smart phones, tablets, laptops, head mounted devices, wearable computers, or other devices that can include a display, a camera (front or rear facing camera), memory, central processing unit, communication interface (such as cellular interface and/or wireless local area network/Bluetooth etc. interface), sensors such as accelerometers, position sensor such as Global System for Positioning (GPS). Users of the portable computing device can use a terminal with a user interface (UI). The typical user interface might include a display and some means of giving feedback such as touch screen or physical buttons. There are portable computing devices which can also receive user input via sensors such as accelerometers. Example of such usage can include controlling of a game by tilting the terminal. In addition to portable computing devices and terminals, some aspects of the present disclosure can be implemented in fixed devices such as desktop computers or embedded in for example a camera of a car or cash machine, food dispenser, home entertainment system.
According to embodiments of the disclosure, the camera of the portable computing device is used as feedback means to control a user interface or to initiate actions in the portable computing device. The feedback is given to the portable computing device as one or more different gestures made with one or more of the hands of the user.
Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “consisting of”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. | A system and method for recognition of hand gesture in computing devices. The system recognizes a hand of a user by identifying a predefined first gesture and further collects visual information related to the hand identified on the basis of the first predefined gesture. The visual information is used to extract a second gesture (and all other gestures after the second) from the video/image captured by the camera and finally interpreting the second gesture as a user input to the computing device. The system enables gesture recognition in various light conditions and can be operated by various user hands including the ones wearing gloves. | 6 |
[0001] This application claims the benefit of provisional application No. 60/847,399 filed on Sep. 11, 2006.
[0002] Electrochemical capacitors (also denoted as supercapacitors or ultracapacitors) are a class of energy-storage materials that offer significant promise in bridging the performance gap between the high energy density of batteries and the high power density derived from dielectric capacitors. Energy storage in an electrochemical capacitor is accomplished by two principal mechanisms: double-layer capacitance and pseudocapacitance.
[0003] Double-layer capacitance arises from the separation of charge that occurs at an electrified interface. With this mechanism the capacitance is related to the active electrode surface area, with practical capacitances in liquid electrolytes of 10-40 μF cm −2 . Electrochemical capacitors based on double-layer capacitance are typically designed with high-surface-area carbon electrodes, including carbon aerogels, foams, nanotube/nanofiber assemblies, and papers. Carbon aerogels and related porous carbons are particularly attractive due to their high surface areas, high porosities, and excellent conductivities (>40 S cm −1 ). Although the high-quality porosity of such carbon nanoarchitectures supports rapid charge-discharge operation, the overall energy-storage capacities of carbon electrodes are ultimately limited by their reliance on the double-layer capacitance mechanism.
[0004] Pseudocapacitance broadly describes faradaic reactions whose current-voltage profiles mimic those of double-layer capacitors. Because this mechanism involves true electron-transfer reactions and is not strictly limited to the electrode surface, materials exhibiting pseudocapacitance often have higher energy densities relative to double-layer capacitors. The two main classes of materials being researched for their pseudocapacitance are transition metal oxides and conducting polymers.
[0005] At present, some of the best candidates for electrochemical capacitors are based on nanoscale forms of mixed ion-electron conducting metal oxides, such as RuO 2 , which store charge via a cation-electron insertion mechanism.
[0000]
[0000] Electrodes based on disordered, hydrous RuO 2 yield specific capacitances up to 720 F g −1 . However, the application of RuO 2 is limited by the high costs of the ruthenium precursors.
[0006] Manganese oxides have recently gained attention as active materials for electrochemical capacitors, primarily due to their significantly lower cost relative to hydrous RuO 2 . A survey of recent publications, combined with research findings at the NRL, shows that when prepared in traditional electrode configurations, such as micron-thick films or in composite electrodes containing carbon and binders, MnO 2 delivers a specific capacitance of ˜200 F g −1 , which is competitive with carbon supercapacitors, but far short of the 720 F g −1 obtained with hydrous RuO 2 . However, as reported independently by Pang et al. and Toupin et al., when MnO 2 is produced as a very thin film (tens of nanometers or less) on a planar current collector, specific capacitances of 700 F g −1 and 1380 F g −1 can be achieved, respectively. This disparity in measured capacitance can be attributed to poor long-range electronic and/or ionic conductivity for MnO 2 , which can inhibit the charge-discharge process in conventional electrode designs. Although ultrathin films of MnO 2 deliver high specific capacitance, this configuration can limit the area-normalized capacitance for practical EC devices.
[0007] Alternatives involve electrode structures incorporating carbon nanotubes (an expensive carbon substrate) or alternative MnO 2 deposition methods (e.g., electrodeposition, sputtering), which are more complicated, costly and more difficult to control.
BRIEF DESCRIPTION OF THE FIGURES
[0008] FIG. 1 shows a schematic of a hybrid electrode structure comprising a highly porous carbon nanostructure coated with nanoscopic MnO 2 deposits.
[0009] FIG. 2 shows a schematic of electrodeposition on an ultraporous electrode structure in (i) a poorly controlled manner in which the pores are ultimately blocked by the growing film and (ii) a controlled, self-limiting deposition.
[0010] FIG. 3 shows scanning electron micrographs of (a and b) 4-h acid-deposited MnO 2 -carbon, (c and d) 4-h neutral-deposited MnO 2 -carbon, and (e and f) bare carbon nanofoam.
[0011] FIG. 4 shows a scanning electron micrograph (top) for the cross-section of a 4-h neutral-deposited MnO 2 -carbon, and corresponding elemental mapping images (middle and bottom) of this same area of the sample for carbon and manganese content, respectively.
[0012] FIG. 5 shows cyclic voltammograms at 2 and 20 mV s −1 in 1 M Na 2 SO 4 for bare carbon nanofoam (—) and 4-h MnO 2 -carbon nanofoam deposited from acidic permanganate solution ( - - - ) and neutral permanganate solution ( . . . ).
[0013] FIG. 6 shows a Nyquist plot and a capacitance vs. frequency profile for acid-deposited, neutral-deposited MnO 2 -carbon nanofoam and bare carbon nanofoam.
[0014] FIG. 7 shows scanning electron micrographs of the surfaces of 4-h neutral-deposited MnO 2 -carbon nanofoams, where AgMnO 4 is the deposition precursor, both with (top) and without (bottom) the addition of a pH 6.9 phosphate buffer.
DESCRIPTION
[0015] Nanostructured MnO 2 -carbon nanoarchitecture hybrids can be designed as electrode structures for high-energy-density electrochemical capacitors that retain high power density. Homogeneous, ultrathin coatings of nanoscale MnO 2 can be incorporated within porous, high-surface-area carbon substrates (such as carbon nanofoams) via electroless deposition from aqueous permanganate under controlled pH conditions. The resulting hybrid structures exhibit enhanced gravimetric, volumetric, and area-normalized capacitance when electrochemically cycled in aqueous electrolytes. This design can be extended to other mesoporous and macroporous carbon forms possessing a continuous pore network.
[0016] The performance limitations of MnO 2 for electrochemical capacitors can be addressed with a hybrid electrode design, by incorporating discrete nanoscale coatings or deposits of MnO 2 onto porous, high-surface-area carbon structures (see FIG. 1 ). In such a configuration, long-range electronic conduction is facilitated through the carbon backbone and solid-state transport distances for ions through the MnO 2 phase can be minimized by maintaining a nanoscopic carbon ∥MnO 2 ∥ electrolyte interface throughout the macroscopic porous electrode. Such a design can be realized using various types of porous carbon substrates including but not limited to aerogels/nanofoams, templated mesoporous carbon, and nanotube/nanofiber assemblies.
[0017] The synthesis and electrochemical characterization of MnO 2 -carbon composites has been reported and primarily focused on incorporating nanoscale MnO 2 deposits onto carbon nanotubes using a variety of approaches including simple physical mixing of the components, chemical deposition using such precursors as KMnO 4 , and electrochemical deposition. In these cases, the incorporation of MnO 2 improves the capacitance of the electrode structures that contain the MnO 2 -modified carbon nanotubes; however, the overall specific capacitance for the composite structures is typically limited to <200 F g −1 , even for electrodes with high weight loadings of MnO 2 . One exception was reported by Lee et al., who demonstrated specific capacitances of up to 415 F g −1 as normalized to the MnO 2 of the composite structure. However, those results were achieved only for micron-thick electrode structures containing MnO 2 -modified carbon nanotubes, again a configuration that limits energy density.
[0018] Templated mesoporous carbon powders have also been used as a substrate for MnO 2 deposition as demonstrated by Dong et al., who used the reaction of permanganate with the carbon substrate to generate nanoscale MnO 2 deposits directly on the mesopore walls. Electrochemical testing of the resulting MnO 2 -mesoporous carbon structures revealed that the MnO 2 deposits themselves exhibited a specific capacitance of ˜600 F g −1 , which approaches the 700 F g −1 reported by Pang et al. for nanometers-thick MnO 2 films. Despite the high MnO 2 -normalized capacitance, the overall specific capacitance of the hybrid MnO 2 -mesoporous carbon structure was limited to 200 F g −1 , due to the relatively low weight loading (up to 26%) of MnO 2 . The extent of MnO 2 deposition within the mesoporous carbon substrate can be limited by the inherently small pore size (˜3 nm) of the carbon.
[0019] The investigations of Dong et al. and Lee et al. demonstrate that nanoscopic deposits of MnO 2 on high-surface-area substrates do deliver high specific capacitance. To further optimize the performance of MnO 2 -carbon hybrid structures for electrochemical capacitor applications, at least three design parameters must be addressed: (i) achieving high weight loadings of MnO 2 (>50 wt. %); (ii) fabricating electrode structures with macroscopic thickness (tens to hundreds of microns); and (iii) retaining a through-connected pore network in 3D and with pores sized at >5 nm.
[0020] The use of thick carbon substrates, as opposed to dispersed carbon powders, presents new challenges for achieving homogeneous MnO 2 deposition throughout the electrode structure, while preserving the native pore structure of the carbon template. A high-quality pore structure is vital for high-rate EC operation, facilitating electrolyte infiltration and ion transport. These properties can be achieved by using coating methods that are inherently self-limiting as shown schematically in FIG. 2 . Described in this disclosure is the self-limiting electroless deposition of nanoscale MnO 2 , based on the redox reaction of aqueous permanganate (MnO 4 − ) and carbon aerogel/nanofoam substrates. The MnO 2 prepared by this protocol is a complex structure incorporating cations and water; this material will be designated as MnO 2 in the body of this application.
EXAMPLE 1 ELECTROLESS DEPOSITION OF MNO 2 ON CARBON NANOFOAMS
[0021] Carbon nanofoam papers were either purchased from a commercial source or prepared in-house. MnO 2 -carbon nanoarchitecture hybrids were created based on the reductive decomposition of permanganate from aqueous solutions. The carbon nanoarchitecture surface can serve as a sacrificial reductant, converting the aqueous permanganate to insoluble MnO 2 .
[0022] Carbon nanofoam substrates (˜170-μm thick) were first wetted in an aqueous solution of controlled pH (0.1 M H 2 SO 4 , 0.1 M Na 2 SO 4 , or 0.1 M NaOH) by vacuum infiltration. The samples were then soaked in 0.1 M NaMnO 4 at each respective pH for a period of 5 min to 4 h. The MnO 2 -carbon nanofoam papers were rinsed thoroughly with ultrapure water and subsequently dried at ˜50° C. under N 2 for 8 hours and then under vacuum overnight.
[0023] Control of the permanganate reduction reaction can be required to achieve nanoscale MnO 2 deposits throughout the carbon nanoarchitecture as well as to inhibit the formation of thick MnO 2 coatings on the outer boundary of the carbon electrode. Preliminary results suggest that pH can be a critical factor in determining the quality of the MnO 2 deposition.
[0024] As shown by the scanning electron micrographs (SEM) in FIGS. 3 a and 3 b , under acidic conditions, permanganate reacts with carbon nanofoams to primarily form thick crusts of MnO 2 on the outer boundary of the carbon electrode, presumably due to the autocatalytic decomposition of permanganate in acid. A cross-sectional image of the acid-deposited MnO 2 crust, shown in the inset of FIG. 3 a , reveals that the crust thickness was ˜4 μm for a 4-h deposition. By contrast, permanganate reduction in neutral or basic pH solutions results in homogeneous MnO 2 deposits (neutral sample, FIGS. 3 c and 3 d ) that are nearly indistinguishable from the bare carbon aerogel ( FIGS. 3 e and 3 f ) with no MnO 2 crust formation at the outer boundary of the nanofoam electrode.
[0025] The MnO 2 mass uptake (up to ˜60% for a 24-h deposition) can be relatively independent of the solution pH. The SEM analysis further confirmed that the porous texture of the initial carbon nanofoam can be largely retained following MnO 2 deposition (see FIGS. 3 d and 3 f ). The retention of the nanofoam's high-quality pore structure can result in better electrochemical performance under high-rate charge-discharge operation.
[0026] The cross-sectional SEM and elemental mapping images of the MnO 2 -carbon nanofoam synthesized under neutral conditions in FIG. 4 show that the Mn can be evenly distributed throughout the thickness of the electrode structure. Incorporation of the MnO 2 domains within the porous carbon nanoarchitectures in such a homogeneous, conformal fashion can result in hybrid electrode structures with superior performance relative to the less ideal structures obtained under acidic deposition conditions. X-ray photoelectron spectroscopy was used to verify that Mn deposits were primarily in the form of Mn III/IV O 2 , with no residual MnO 4 —.
EXAMPLE 2 ELECTROCHEMICAL CHARACTERIZATION OF HYBRID STRUCTURES
[0027] The MnO 2 -carbon nanofoam electrodes were wetted with 1 M Na 2 SO 4 under vacuum for electrochemical analysis and characterized in a conventional three-electrode electrochemical cell using techniques such as cyclic voltammetry, impedance spectroscopy, and galvanostatic charge-discharge measurements. Representative cyclic voltammograms of the bare carbon aerogel, 4-h acid-deposited, and 4-h neutral-deposited MnO 2 -carbon nanofoam electrodes in 1 M Na 2 SO 4 at 2 and 20 mV s −1 are presented in FIG. 5 .
[0028] A saturated calomel reference electrode (SCE) and reticulated vitreous carbon auxiliary electrode were used in all electrochemical measurements. At 2 mV s − , all curves exhibit a nearly symmetrical rectangular shape, indicative of relatively low uncompensated electrode or solution resistance. The gravimetric (normalized to total sample mass), volumetric, and area-normalized capacitance values calculated from these curves between 0.1 and 0.6 V vs. SCE are presented in Table 1. Both the total gravimetric and volumetric capacitance values increase for the acid- and neutral-deposited samples. Notably, the gravimetric capacitance increases by a factor of 2 for the neutral-deposited sample, while the volumetric capacitance is over 4 times greater. It is important to note that in the case of homogeneous, nanoscopic MnO 2 deposits like those in the neutral-deposited hybrid electrode, the incorporation of MnO 2 can contribute additional capacitance without increasing the bulk volume of the electrode structure.
[0029] When pulse power is required in a footprint- or area-limited configuration, as in microelectromechanical (MEMS) based and on-chip devices, the area-normalized energy-storage capacity should also be considered. Although the area-normalized capacitance is often not reported for MnO 2 /carbon composites, it is usually around 10-50 mF cm −2 . In contrast, the present hybrid electrode design maintains the advantages of a nanoscopic electrode/electrolyte interface while projecting the electrode structure in three dimensions with a limited footprint, such that the area-normalized capacitance for the neutral-deposited MnO 2 -carbon hybrid electrodes is orders of magnitude greater at ≦2 F cm −2 .
[0030] The upper and lower limits of capacitance attributed to MnO 2 in Table 1 were estimated using one of two assumptions: (1) all capacitance arises from the MnO 2 phase (upper limit) or (2) the total sample capacitance was the sum of the carbon double-layer capacitance and the MnO 2 capacitance (lower limit). Although the capacitance attributable to the MnO 2 phase for the acid- and neutral-deposited samples likely falls within this range, the capacitance contribution from the carbon is expected to be different for the acid and neutral case because of the variation in the MnO 2 spatial distribution. For example in the acid case, the double-layer capacitance contribution of carbon should be largely unaffected due to the limited MnO 2 deposition in the electrode interior. Thus, the MnO 2 -normalized capacitance is likely near the lower estimated limit, while that for the neutral sample is expected to be higher as a result of extensive MnO 2 coating the carbon on the electrode interior.
[0031] Although the total capacitance enhancement for the acid and neutral-deposited MnO 2 samples presented in Table 1 is similar, the difference in the spatial distribution of MnO 2 for the two samples results in a sloping voltammetric curve for the boundary-crusted, acid-deposited MnO 2 -carbon nanofoam at 20 mV s −1 due to increasing resistance that results from non-uniform MnO 2 deposition. This increased resistance is confirmed by electrochemical impedance analysis (EDC=200 mV vs. SCE) presented in FIG. 6 (similar results were observed at 0 and 600 mV).
[0032] At high frequencies, the uncompensated solution resistance (R Ω ) of each electrode is similar, as shown in the Nyquist plot ( FIG. 6 a ). However, the large hemispherical component for the MnO 2 -carbon nanofoam electrode deposited under acidic conditions is indicative of polarization as expressed by a charge-transfer resistance (R p ) of about 15Ω. In contrast, the profile for the neutral-deposited sample is more similar to that of the bare carbon nanofoam, with an R p of ˜1Ω. The capacitance vs. frequency profile of the neutral-deposited sample in FIG. 6 b shows that from about 0.01 to 1 Hz, the MnO 2 component can increase the capacitance of the bare carbon nanofoam. As the frequency increases, the capacitance for both electrodes begins to decrease, falling to below 1 F g −1 around 200 Hz. The initial capacitance increase for the acid-deposited sample at 0.01 Hz, with respect to the bare nanofoam, can be much lower than that for the neutral-deposited sample and begins to decrease between 0.1 and 1 Hz, falling below 1 F g −1 at 30 Hz.
[0033] The higher resistance and lower capacitance for the acid-deposited sample is likely due to the thick MnO 2 crust that forms on the electrode exterior, hindering electron and ion transport, while the more ideal homogeneous distribution of MnO 2 in the sample deposited under neutral conditions results in electrochemical characteristics more similar to the bare nanofoam.
[0000]
TABLE 1
Specific
MnO 2 -specific
Volumetric
Area-normalized
capacitance
capacitance range
capacitance
capacitance
(F g −1 C+MnO 2 )
(F g −1 MnO 2 )
(F cm −3 )
(F cm −2 )**
Bare nanofoam
53
—
20
0.56
Acid-deposited
92
150-220
81
1.4
Neutral-deposited
110
170-230
90
1.5
*These data are derived for 4-h depositions from acidic or neutral permanganate solutions.
**Normalized to the geometric area of one face of the nanofoam electrode.
[0034] The electroless deposition described herein can be a simple, cost-effective, and scaleable approach for synthesizing MnO 2 -carbon hybrid nanoarchitectures with electrochemical capacitance that is superior to unmodified carbon substrates. This disclosure demonstrates that by controlling solution pH during the deposition process, homogeneous MnO 2 deposits are achieved throughout macroscopically thick porous carbon templates.
[0035] There can be many benefits of homogenous MnO 2 deposition as can be evident when such structures are electrochemically analyzed. For example, MnO 2 -carbon hybrids that exhibit uniform MnO 2 distribution (neutral-pH deposition) also exhibit higher overall gravimetric and volumetric capacitance, and higher MnO 2 -specific capacitance than acid-deposited MnO 2 -carbon hybrids, in which the MnO 2 is primarily deposited as a crust on the outer boundaries of the electrode.
[0036] Uniform deposition within the interior of the carbon nanoarchitecture also can result in greater enhancement when the volumetric capacitance is considered, as the addition of the MnO 2 component contributes additional capacitance without increasing the bulk volume of the electrode structure. For example, with a carbon nanofoam coated under neutral-pH conditions the gravimetric capacitance is increased by a factor of 3.3, while the volumetric capacitance is increased by a factor of 4.1. Even greater enhancements in electrochemical performance for these hybrids can be realized with further optimization of the electroless deposition conditions (e.g., varying the solution temperature, precursor concentration, permanganate counterion—including transition metal speciation, constituents that define the acidic or neutral medium including buffers) and also by varying the carbon template pore structure, particularly targeting larger pore sizes (100-200 nm) and higher overall porosity, which should result in higher mass loadings of MnO 2 .
[0037] In an example of two modifications to the deposition protocol, carbon nanofoams were soaked in nominally neutral aqueous solutions of commercially available AgMnO 4 (substituted for NaMnO 4 ) under buffered and unbuffered conditions. The morphology of the resulting Ag x Mn III/IV 1-x O 2 deposits is affected by the presence or absence of buffering agents. Without buffer, the oxide coating is more nodular and preferentially deposited on the outer boundary, while from buffered medium, the deposit is more uniformly distributed, not nodular, and less thick (as seen in FIG. 7 ).
[0038] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that the claimed invention may be practiced otherwise than as specifically described. Any reference to claim elements in the singular, e.g., using the articles “a,” an, “the,” or “said” is not construed as limiting the element to the singular. | A method of forming a composite comprising the steps of providing a porous carbon structure comprising a surface and pores and infiltrating the structure with a coating comprising MnO 2 without completely filling or obstructing a majority of the pores. A method of storing charge comprising the steps of providing a capacitor comprising an anode, a cathode, and an electrolyte, wherein the anode, the cathode, or both comprise a composite comprising a porous carbon structure comprising a surface and pores and a coating on the surface comprising MnO 2 wherein the coating does not completely fill or obstruct a majority of the pores and a current collector in electrical contact with the composite, and charging the capacitor. | 8 |
BACKGROUND OF THE INVENTION
Due to the poor design of conventional AC power plugs, the power cord can be pulled and detached from the outer plug housing or pulled and detached from the wire connector terminals. Furthermore, since the design of the plug base is inappropriate, it is troublesome to replace the safety protection fuse and thus subjects the user to inconvenience and danger.
The primary objective of the invention herein is to remedy the aforementioned shortcomings by introducing significant improvements, wherein the base and outer housing assembly method and built-in safety fuse are configured in a new design. Since the assembly fastening section is positioned quite a distance away from the safety fuse, the assembly tightness is not affected by overheating, thereby facilitating maximum user safety and convenience.
The preferred embodiment of the invention herein is illustrated by the following brief descriptions of the drawings and detailed description of the invention herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the present invention;
FIG. 2 is a perspective exploded view of the present invention;
FIG. 2-1 is another perspective exploded view of the present invention;
FIG. 2-2 is a plan view of a plug of the present invention;
FIG. 3 is an elevation view in partial cross-section of the present invention;
FIG. 4 is a perspective view of the assembly interface between the base and the lower section of the outer housing;
FIG. 5 is a partial cross-sectional view of the interface shown in FIG. 4;
FIG. 6 is another cross-sectional view of the interface shown in FIG. 4;
FIG. 7 is another perspective exploded view of the present invention further illustrating the assembly interface between the base and the outer housing;
FIG. 8 is a partial cross-sectional view of the interface illustrated in FIG. 7;
FIG. 9 is a cross-sectional view depicting the wire installation within the conductor connection structure;
FIG. 10 is a cross-sectional view depicting the wire installation within the conductor connection structure;
FIG. 11 is a cross-sectional view of the safety fuse section of the conductor structure of the present invention;
FIG. 12 is a cross-sectional view illustrating the automatic ejection of the safety fuse when the horizontal retaining cover is removed;
FIGS. 13, 13-1, 13-2, 13-3, 13-4, and 13-5 are perspective views of the base of the present invention showing the relative position of the safety fuse;
FIG. 14 is a perspective view of a safety fuse utilized in the present invention;
FIG. 14-1 is a cross-sectional view of the safety fuse shown in FIG. 14;
FIG. 15 is a perspective view of the double safety fuses utilized in the present invention;
FIG. 15-1 is cross-sectional view of the double safety fuses shown in FIG. 15; and,
FIG. 15-2 is an end view of the double safety fuses shown in FIG. 15.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As indicated in FIGS. 1 and 2, the AC power plug is comprised of an outer housing 10, a base 20 and a conductor assembly 30. As also shown in FIGS. 2-1 and 2-2, it can be seen that there are two T-shaped conductor insertion holes 11 through the front end of the outer housing 10 as well as a safety fuse enclosure cover hole 12 for the insertion of the safety fuse enclosure cover. On the upper surface of the outer housing 10, there is a safety fuse entryway 17. As indicated in FIG. 5 and FIG. 6, the lower inner surface of the outer housing 10 has a protruding edge 14, a slotted center hole 18 and a pair of lateral slots 15. The inside of each of the T-shaped conductor insertion holes 11 has a support 16, as indicated in FIG. 3.
The base 20 is a single unitary structure consisting of an upper section and a lower section, wherein the upper section includes a left barrier plate 21, a right barrier plate 22 and a center partition 23 positioned between the left wall 24 and the right wall 25. Furthermore, there is an opening 231 formed in the rear side of the center partition 23 to create additional internal space and form a strain relief for the wires 33. As indicated in FIGS. 4 to 6, the lower section of the base 20 includes a center tab 26, a pair of spaced lateral tabs 27 and a wire insertion hole 28.
The conductor assembly 30 includes two conductor strips 31, two fuses 32, a pair of fuse holders 33 and wires 34. Each of the two conductor strips 31 has a spring-type retaining tab 311 and a conductor tip 312 that fits into the interior sides of the right barrier plate 22 and the left barrier plate 25, respectively. The conductor tips 312 of each conductor strip 31 are inserted through the channel 35 between a respective barrier plate 22, 21 and the front of its base 30, and between a respective barrier plate 22, 21 and the center partition 23. Each wire 34 is permanently connected to a fuse holder 33, each fuse holder 33 has two conductor strips 331. Each fuse holder 33 is first inserted into the entry retainer in the base 20, as indicated in FIG. 9, and rotated 90 degrees, as indicated in FIG. 10. Then, a fuse 32 is placed into the fuse holder 33 between the conductor strips 331 and the conductor tips 312. Subsequent to installation of the second fuse 32, the wires 34 are separated, as indicated in FIGS. 2, 2-1, and 2-2, and routed through the opening 231 in opposing directions, and the wire insertion hole 28.
After the conductor assembly 30 is secured into the base 20, the base 20 and the outer housing 10 are assembled together. Following the insertion of the long conductor strips 31 through the T-shaped conductor insertion holes 11, the spring-type retaining tabs 311 are interlocked onto the support 16, respectively, as indicated in FIG. 3, to complete the first stage of fastening. With respect to the lower section of base 20, as indicated in FIG. 4, FIG. 5 and FIG. 6, in the process of assembling the base 20 to the outer housing 10 the center tab 26 is interlocked into the center slot 18, as indicated in FIG. 6, and the lateral tabs 27 are interlocked into the lateral slots 15, as indicated in FIG. 5 to complete the second stage of fastening.
The fuses 32 are installed from the safety fuse entryway 17 through the upper surface of the outer housing 10, enabling the fuse enclosure cover 13 to be secured into the safety fuse enclosure cover hole 12. As indicated in FIG. 11 and FIG. 12, each fuse 32 is pressed down by the fuse enclosure cover 13, and the conductor strips 331 are wedged open. However, due to the design of the center partition 23, the maximum opening width of the conductor strips 331 is limited by the distance between the center partition 23 and the respective barrier plate 21, 22 to prevent the conductor strips 331 from losing elasticity over a prolonged period of time and thus unable to maintain sound electrical contact. When the fuse enclosure cover 13 is opened, the tension of the conductor strips 331 is released against the fuses 32, and thereby ejects the fuses 32 for replacement. Another feature of the invention herein is indicated in FIG. 7 and FIG. 8, which are further design enhancements of the structure shown in FIG. 4. Two lateral slots 15' are formed in the outer housing 10, and two lateral tabs 27' are positioned on the base 20. This structure enables the assembly of the outer housing 10 to the base 20 with the lateral tabs 27' being directly interlocked into the lateral slots 15', as indicated in FIG. 8.
As indicated in FIGS. 13 to 13-5, there are shown some modifications in the fuse access arrangement. As shown, recess 21' can be molded at a suitable location into the underside of the base 20, a corresponding opening 11' formed in outer housing 10, and a cover plate 12' added to the outer housing 10 to enable fuses 32' to be installed into the recess 21', thereby facilitating consumer operating convenience.
As indicated in FIGS. 14, 14-1, 15, 15-1, and 15-2, in order to prevent the metal end contacts 322" from becoming accidentally detached from the main body 321" of the fuses 32" due to the opening and closing of the fuse enclosure cover 13, the main body 321" of the fuse 32" is designed with a protruding section that is of a wider diameter than the metal end contacts 322". This prevents the detachment of the metal end contacts 322" due to the influence of the fuse enclosure cover 13, which may otherwise accidentally cause a situation of poor electrical contact.
In summation of the foregoing description, the disclosed AC power plug has the special characteristics of originality, practicality and enhanced function that enables the inclusion of two safety devices inside the AC plug. The disclosed AC plug has built-in safety protection fuses and provisions for the sturdy interlocking of the base to the outer housing. Furthermore, the safety protection fuses are maintained in a state of safe electrical contact to thereby attain a major increase in function. | An improved AC power plug structure is provided. The AC power plug consists of an outer housing, base and conductor structure which utilize differently positioned connection methods. The base and the outer housing are firmly assembled together, while the conductor wires within the base are separately routed so the conductor wires cannot be pulled from their connection with the wire terminals. Further, a pair of special built-in safety fuses are located inside the base. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to the production of hexahydro-iso-alpha-acids (hexahydro-isohumulones or hexahydro-isohumulates) by the hydrogenation of iso-alpha-acids (isohumulones or isohumulates) or tetrahydro-iso-alpha-acids (tetrahydro-isohumulones or tetrahydro-isohumulates) by using a heterogeneous ruthenium containing catalyst that catalyzes the hydrogenation from iso-alpha-acids or tetrahydro-iso-alpha-acids to hexahydro-iso-alpha-acids.
BACKGROUND OF THE INVENTION
[0002] The invention relates to the production of hexahydro-iso-alpha-acids, which are reduced derivatives of iso-alpha-acids, useful to impart bitterness and foam to beer. These hexahydro-iso-alpha-acids are bitter hop acid derivatives with excellent foam-stabilizing properties, and preferable to all other iso-alpha-acid products in terms of resistance to photolytic and oxidative degradation (U.S. Pat. No. 3,552,975).
[0003] Traditionally, the bitter beer flavor derives from the alpha-acids present in hop cones. During the wort boiling stage of the conventional brewing process, the alpha-acids are extracted from the (powdered) hop cones and partly converted to the corresponding bitter iso-alpha-acids. However, the hop utilization (or the iso-alpha-acid yield) in the traditional brewing process is only about 35% (GB 1,158,697).
[0004] It became clear that the hop utilization can be improved by performing the alpha-acid isomerisation outside the brewing process and more specifically by off-line pre-isomerising the alpha-acids under the effect of inorganic basic compounds (U.S. Pat. No. 3,962,061; U.S. Pat. No. 4,002,683; U.S. Pat. No. 4,758,445; U.S. Pat. No. 5,015,491; U.S. Pat. No. 5,155,276; U.S. Pat. No. 5,370,897). The use of such off-line produced iso-alpha-acids improves the utilization of the hop alpha-acids in the brewing process to about 70% at most.
[0005] The iso-alpha-acids have however a number of intrinsic disadvantages. One such negative property is their sensitivity to photolytic degradation which leads to the development of the so-called ‘lightstruck flavor’ which is ascribed to the formation of 3-methyl-2-butene-1-thiol (MBT), also called ‘skunky thiol’. The occurrence of the photolytic reaction is a consequence of the presence of an iso-3-hexenoyl side chain in the iso-alpha-acid molecules. By modifying the molecular structure of the iso-alpha-acids, for example by reducing the C═C and/or C═O bonds in this iso-3-hexenoyl side chain, substantial MBT by-product formation, e.g. in beer, as a consequence of photolytic degradation can be prevented.
[0006] Consequently, reduced iso-alpha-acid derivatives have been introduced, to say dihydro-iso-alpha-acids, tetrahydro-iso-alpha-acids and hexahydro-iso-alpha-acids, and are now used by many brewers, generally by their addition after the primary fermentation stage of the brewing process. The dihydro-iso-alpha-acids (also called rho-iso-alpha-acids) are obtained by the reduction of the carbonyl group in the aforementioned iso-3-hexenoyl chain to a hydroxyl group, generally using alkali metal borohydride as the reducing agent. The tetrahydro-iso-alpha-acids are obtained via hydrogenation of the C═C bonds in the aforementioned iso-3-hexenoyl side chain and the isopentenyl side chain. The hexahydro-iso-alpha-acids are produced by combining the aforementioned reduction and hydrogenation processes.
[0007] All industrially applied procedures for the production of dihydro-iso-alpha-acids use a borohydride based reduction of iso-alpha-acids (U.S. Pat. No. 3,558,326; U.S. Pat. No. 4,324,810). The industrial processes for the production of tetrahydro-iso-alpha-acids generally apply heterogeneous Pd based catalysts (U.S. Pat. No. 5,013,571; U.S. Pat. No. 5,600,012).
[0008] For the formation of hexahydro-iso-alpha-acids two approaches have been described. The first type uses tetrahydro-iso-alpha-acids as the precursor and the desired hexahydro-iso-alpha-acids are obtained by a reduction using an alkali metal borohydride (U.S. Pat. No. 3,552,975). A second approach starts from dihydro-iso-alpha-acids, which are hydrogenated with hydrogen gas over a supported Pd catalyst (U.S. Pat. No. 5,013,571).
[0009] U.S. Pat. No. 3,552,975 describes the formation of the ‘skunk-proof’ hexahydro-iso-alpha-acids starting from tetrahydro-iso-alpha-acids, by using an alkali metal borohydride as the reducing agent, water and/or alcohol solvents as preferred inert protic reaction media, and mild alkaline pH conditions. After the reduction process, the excess reductant is decomposed by adding an aqueous HCl solution, and the hexahydro-iso-alpha-acids are recovered via extraction with a water-immiscible solvent (e.g. lower hydrocarbons or ethers). To obtain the hexahydro-iso-alpha-acid product in high purity, an additional solvent evaporation step is required.
[0010] U.S. Pat. No. 6,198,004 describes a process for converting iso-alpha-acids to tetrahydro-iso-alpha-acids by means of incremental or continuous addition to the reaction mixture of noble metal catalysts, preferably Pd catalysts, that catalyze the hydrogenation of the iso-alpha-acids towards tetrahydro-iso-alpha-acids, as supported by Pd catalyst based experimental data. However, U.S. Pat. No. 6,198,004 also teaches that when hexahydro-iso-alpha-acids are the desired products, the tetrahydro-iso-alpha-acid needs to be further reduced in a reduction step, that particularly employs a reducing agent of the alkali metal borohydride type.
[0011] U.S. Pat. No. 5,013,571 describes the reduction of iso-alpha-acids to dihydro-iso-alpha-acids with alkali metal borohydride compounds and the subsequent hydrogenation to hexahydro-iso-alpha-acids over Pd catalysts, with carbon, barium carbonate, barium sulphate, calcium carbonate or alumina as the supporting material. This patent also reflects the critical nature of these reduction and hydrogenation processes, by reporting side chain cleavage, during the reduction process as a consequence of the alkaline pH conditions, and during the hydrogenation process resulting from hydrogenolysis.
[0012] Approaches to avoid these perhydrogenation products are described in U.S. Pat. No. 5,600,012. If undesired side products resulting from hydrogenolytic degradation are present in the product, an additional extraction step using e.g. hexane is required to remove these degradation products followed by a solvent evaporation step to obtain the purified hexahydro-iso-alpha-acids.
[0013] U.S. Pat. No. 7,344,746 describes the production of hexahydro-iso-alpha-acids from dihydro-iso-alpha-acids via a (solvent-free) hydrogenation process using Pd and Pt based catalysts, with possible admixing of carbon dioxide, which can be performed in batch or continuous mode.
[0014] The above clearly shows that the transformation of hop iso-alpha-acids to hexahydro-iso-alpha-acids known in the art requires complex multistep processes, comprising hydrogenation and (alkali metal borohydride based) reduction reactions, with often the unwanted formation of degradation by-products (e.g. side chain cleavage and hydrogenolysis) that need to be removed by means of extraction and evaporation processes. Thus, there remains a need for improved, simplified methods to obtain hexahydro-iso-alpha-acids from iso-alpha-acids or tetrahydro-iso-alpha-acids.
SUMMARY OF THE INVENTION
[0015] The present invention relates to a method for the one-step production of hexahydro-iso-alpha-acids (hexahydro-isohumulones or hexahydro-isohumulates) using a heterogeneous ruthenium containing catalyst that catalyzes the hydrogenation of the iso-alpha-acid or the tetrahydro-iso-alpha-acid to the hexahydro-iso-alpha-acid, and to the hexahydro-iso-alpha-acid composition obtainable by said method.
[0016] Thus, a first aspect of the present invention provides a method for hydrogenating an iso-alpha-acid or a tetrahydro-iso-alpha-acid to a hexahydro-iso-alpha-acid comprising (i) contacting or mixing the iso-alpha-acid reactant (e.g. in the form of an iso-alpha-acid, an alkali metal isohumulate or an alkaline earth metal isohumulate) or the tetrahydro-iso-alpha-acid reactant (e.g. in the form of a tetrahydro-iso-alpha-acid, an alkali metal tetrahydro-isohumulate or an alkaline earth metal tetrahydro-isohumulate) with a heterogeneous ruthenium containing catalyst, that catalyzes the hydrogenation of said iso-alpha-acid or said tetrahydro-iso-alpha acid to the hexahydro-iso-alpha-acid, in the absence or in the presence of a solvent (such as carbon dioxide, water, ethanol or another organic solvent, or mixtures thereof) and in the absence or presence of other hop compounds (such as alpha acids or beta-acids), and (ii) holding this mixture under a hydrogen containing atmosphere. The hydrogen containing atmosphere may be obtained by pressurizing the reaction mixture with pure hydrogen or with hydrogen diluted with another gas, preferably an inert gas, such as nitrogen, helium, argon, carbon dioxide or a mixture thereof.
[0017] In contrast to what is known in the prior art, the method according to the present invention does not comprise an additional reduction reaction with an inorganic reducing agent to obtain hexahydro-iso-alpha-acids, such as an alkali metal borohydride based reducing agent (e.g. sodium or potassium borohydride) or an aluminium hydride based reducing agent (e.g. lithium aluminium hydride).
[0018] In a preferred embodiment of the present invention the hydrogenation reaction is carried out at a reaction temperature of at least 293 K, preferably in the range of 293 K to 398 K, more preferably between 333 K and 373 K, and most preferably between 343 K and 363 K. In another preferred embodiment the hydrogenation reaction is carried out using partial pressures of hydrogen varying between 0.02 MPa and 10.0 MPa, and more preferably between 0.1 MPa and 5.0 MPa, and most preferably between 0.2 MPa and 2.0 MPa.
[0019] The reaction time of the hydrogenation reaction is sufficient to achieve more than 99% conversion of the iso-alpha-acids (or the tetrahydro-iso-alpha-acids), both either in free acid form or in dissociated form (e.g. as in an isohumulate or a tetrahydro-isohumulate), with more than 90% selectivity to hexahydro-iso-alpha-acids (in free acid form or as a hexahydro-isohumulate).
[0020] The method according to the present invention may further comprise the step of isomerising an alpha-acid to said iso-alpha-acid (or a tetrahydro-alpha-acid to said tetrahydro-iso-alpha-acid) prior to or in the same reaction medium as the hydrogenation reaction.
[0021] The method according to the present invention may further comprise the step of separating the heterogeneous ruthenium containing catalyst from the obtained hexahydro-iso-alpha-acid product phase after the hydrogenation process, for instance by centrifugation, filtration, decantation or by another liquid-solid separation technique.
[0022] In a preferred embodiment of the present invention the heterogeneous ruthenium containing catalyst is a heterogeneous hydrogenation catalyst, comprising ruthenium on a supporting material, containing at least 0.1 weight % of ruthenium (based on total catalyst weight, including the supporting material) and at least 5 weight % of ruthenium on metals basis, with metals from the group of Ag, Au, Co, Cu, Ir, Ni, Pd, Pt, Rh and Ru. The supporting material of these Ru containing catalysts can be a carbon based material, an oxide or a hydroxide, a synthetic polymer, a biopolymer, a metallic structure, an organic-inorganic hybrid material, a zeolite, a clay or a salt material. Ruthenium is present in a metallic, hydroxide or oxide state. Preferably, the heterogeneous ruthenium containing catalyst is a ruthenium containing catalyst with carbon or alumina as the supporting material.
[0023] Next to ruthenium also one or more other (noble) metals e.g. Ag, Au, Co, Cu, Ir, Ni, Pd, Pt and Rh, can be part of the hydrogenation catalyst leading to hexahydro-iso-alpha-acids, and these (noble) metals can be present as a separate phase or a mixed phase with ruthenium or as an alloy. Also, the combination of a ruthenium containing catalyst together with another heterogeneous hydrogenation catalyst can be applied, for example the combination of Ru and Pd catalysts (with high and selective C═C hydrogenation activity). Ruthenium can be present in these hydrogenation catalysts in its metallic state or in a hydroxide or an oxide state.
[0024] Preferably, the mean particle size of the ruthenium fraction or ruthenium clusters present in the ruthenium containing catalysts is at least 1 nm and at most 1000 nm as measured by transmission electron microscopy.
[0025] In another preferred embodiment of the method of the present invention the molar ratio of the iso-alpha-acid or tetrahydro-iso-alpha-acid, either in free acid form or in dissociated form (as in isohumulates and tetrahydro-isohumulates), to the ruthenium fraction of the hydrogenation catalyst is between 1 and 2000, preferably between 10 and 500, more preferably between 20 and 200.
[0026] Another object of the present invention provides a hop hexahydro-iso-alpha-acid composition obtainable by the method according to the present invention. Particularly said hop hexahydro-iso-alpha-acid composition comprises at least 50, 60, 70 or 80 weight %, preferably at least 85 or 90 weight % hexahydro-iso-alpha-acids (based on total mass of alpha-acids, iso-alpha-acids and their hydrogenated and/or reduced derivatives), wherein said hexahydro-iso-alpha-acid composition is essentially free of inorganic compounds originating from an inorganic reducing agent, particularly a borohydride based reducing agent. Preferably, said hexahydro-iso-alpha-acid composition comprises less than 50 ppm of boron species as measured by elemental analysis. The hexahydro-iso-alpha-acid may be in its free acid form or in dissociated form. Said hop hexahydro-iso-alpha-acid composition may be solvent-free or the hexahydro-iso-alpha-acid may be dissolved in a suitable solvent.
DETAILED DESCRIPTION
List of Figures
[0027] FIG. 1 shows the hydrogenation reaction of a hop iso-alpha-acid to a hexahydro-iso-alpha-acid, as catalyzed by the heterogeneous ruthenium containing catalysts, according to the present invention. In general, R is a lower alkyl, preferably a C 1 -C 6 alkyl.
R═—CH 2 CH(CH 3 ) 2 : n-:
[0028] R═—CH(CH 3 ) 2 : co-;
R═—CH(CH 3 )CH 2 CH 3 : ad-;
R═—CH 2 CH 2 CH(CH 3 ) 2 : pre-;
R═CH 2 CH 3 : post-.
[0029] FIG. 2 shows the hydrogenation of dihydro-iso-alpha-acids and tetrahydro-iso-alpha-acids in water with Ru/C catalyst, particularly the time dependency of the reactant conversion.
DESCRIPTION
[0030] Surprisingly, the inventors found that the use of heterogeneous ruthenium containing catalysts allows a one-step reaction, more particularly a one-step hydrogenation, of hop iso-alpha-acids to hexahydro-iso-alpha-acids, without the need of a reduction step with an inorganic reducing agent, such as by using an alkali metal borohydride. Thus, the heterogeneous ruthenium containing catalyst is capable of catalyzing the hydrogenation of the C═C bonds of the iso-3-hexenoyl side chain and the isopentenyl side chain as well as the C═O bond of the iso-3-hexenoyl side chain. In contrast, the hydrogenation catalysts known in the art, such as the Pd containing catalysts, only catalyze the hydrogenation of the C═C bonds of the iso-3-hexenoyl side chain and the isopentenyl side chain. When using the hydrogenation catalysts known in the art (e.g. a Pd and Pt containing catalyst), the reduction of the C═O bond of the iso-3-hexenoyl side chain requires an additional reduction step using an inorganic reducing agent, such as sodium or potassium borohydride.
[0031] The present invention provides an improved process for the conversion or hydrogenation of iso-alpha-acids to hexahydro-iso-alpha-acids using heterogeneous ruthenium containing catalysts, as schematically presented in FIG. 1 . Thus, the present invention relates to a method for the hydrogenation of iso-alpha-acids comprising mixing an iso-alpha-acid containing feed and a heterogeneous ruthenium containing catalyst, in the presence of hydrogen gas (either pure or as a mixture with another gas), in the absence or in the presence of a suitable solvent, and in the absence or presence of other hop compounds (such as alpha-acids and beta-acids). Using the heterogeneous ruthenium containing catalysts and with alpha-acids and beta-acids in the process feed, the alpha-acids and beta-acids are hydrogenated to respectively tetrahydro-alpha-acids and hexahydro-beta-acids. The heterogeneous ruthenium containing catalyst is capable of catalyzing the hydrogenation of the C═C bonds in the isopentenyl side chains of the alpha-acids (with two isopentenyl side chains) and the beta-acids (with three isopentenyl side chains).
[0032] In the context of the present invention, the iso-alpha-acid containing feed is preferably a pre-isomerized alpha-acid extract, obtained by isomerisation of a hop extract, such as a hop alpha-acid enriched extract, with said hop extract preferably obtained by liquid or supercritical carbon dioxide extraction. In another embodiment of the present invention, the iso-alpha-acid containing feed can also be a mixture containing isohumulates or a solution of isohumulates (dissociated iso-alpha-acids), such as alkali metal isohumulates or alkaline earth metal isohumulates, in a solvent like water, carbon dioxide, organic solvents (including but not limited to methanol, ethanol, 1-propanol, 2-propanol or mixtures of those alcohol solvents) or mixtures thereof.
[0033] The invention also relates to a process for the hydrogenation of tetrahydro-iso-alpha-acids to hexahydro-iso-alpha-acids using heterogeneous ruthenium containing catalysts comprising mixing a tetrahydro-iso-alpha-acid containing feed (tetrahydro-iso-alpha-acids, in non-dissociated form or in dissociated form), and a heterogeneous ruthenium containing catalyst, in the presence of hydrogen gas (either pure or as a mixture with another gas), in the absence or in the presence of a suitable solvent, and in the absence or in the presence of other hop compounds (such as alpha-acids and beta-acids).
[0034] The invention also relates to a process for the substantially simultaneous isomerisation and hydrogenation of alpha-acids to hexahydro-iso-alpha-acids (and of tetrahydro-alpha-acids to hexahydro-iso-alpha-acids). By “substantially simultaneous” is meant that the isomerisation and hydrogenation occur in the same reaction medium, catalyzed by their respective catalysts, i.e. a suitable isomerisation catalyst and a heterogeneous ruthenium containing hydrogenation catalyst. Preferably, the process conditions are selected to assure that the isomerisation step precedes the hydrogenation reaction within the reaction medium. However, if the hydrogenation of the alpha-acids should occur prior to the alpha-acid isomerisation, this will result in the formation of predominantly tetrahydro-alpha-acids, which will next be isomerized to tetrahydro-iso-alpha-acids. Subsequently, these tetrahydro-iso-alpha-acids will be hydrogenated to hexahydro-iso-alpha-acids over the heterogeneous ruthenium containing catalyst according to the present invention. Suitable isomerisation catalysts for the isomerisation of hop alpha-acids are well known to the person skilled in the art. Preferably, said catalyst for the isomerisation of alpha-acids to iso-alpha-acids (or tetrahydro-alpha-acids to tetrahydro-iso-alpha-acids) is an alkaline earth metal based compound, acting as a heterogeneous catalyst, which essentially does not dissolve in the alpha-acid containing feed or in the (reduced) iso-alpha-acid product phase. More preferably said isomerisation catalyst is an alkaline earth metal based inorganic material of the aluminate, titanate, silicate or hydroxyapatite type, containing magnesium, calcium, strontium or barium or mixtures thereof.
[0035] In a preferred embodiment of the present invention, said method further comprises the step of holding the mixture under a hydrogen containing atmosphere, whereby said atmosphere is created by pressurizing the mixture using either pure hydrogen gas or hydrogen mixed with another gas, preferably an inert gas, such as nitrogen, argon, helium, carbon dioxide or a mixture thereof. Preferably, said reaction mixture is subjected in the presence of hydrogen gas to a temperature at which the iso-alpha-acid or tetrahydro-iso-alpha-acid containing reaction medium is sufficiently low in viscosity to allow easy mixing with the hydrogenation catalyst, preferably while stirring. Preferably, said temperature is at least 293 K. More preferably, the hydrogenation reaction is allowed to proceed for a time sufficient to achieve more than 95%, most preferably more than 99% conversion of the iso-alpha-acids (or tetrahydro-iso-alpha-acids) with more than 90% selectivity to hexahydro-iso-alpha-acids (in non-dissociated or in dissociated form, as for hexahydro-isohumulates). As understood by a person of ordinary skill in the art, the reaction time to obtain a >90% yield of hexahydro-iso-alpha-acids is, given a specific substrate to ruthenium ratio and for a specific iso-alpha-acid or tetrahydro-iso-alpha-acid containing process feed, dependent on the characteristics of the heterogeneous ruthenium containing catalyst, including but not limited to the mean particle size or the particle size distribution of the ruthenium clusters or the ruthenium fraction occurring in the ruthenium containing catalyst and the type of supporting material, and also dependent on the applied process conditions, such as reaction temperature and hydrogen pressure.
[0036] In the context of the present invention, the heterogeneous ruthenium containing catalysts are hydrogenation catalysts containing at least 0.1 weight % of ruthenium (on total mass of the catalyst, including supporting material) and at least 5 weight % of ruthenium on metals basis, with metals from the group of Ag, Au, Co, Cu, Ir, Ni, Pd, Pt, Rh and Ru. The supports of these ruthenium containing catalysts can be carbon based (e.g. carbon or activated carbon with varying pore and particle size, carbon nanotubes, graphene type materials), (hydr)oxides (e.g. single oxides or mixed oxides based on Mg, Ca, Sr, Ba, Al, Ti, Si), synthetic polymers (e.g. polyvinylpyrolidone), biopolymers (e.g. chitosan), metallic structures (e.g. metal gauze), organic-inorganic hybrid materials (e.g. metallo-organic frameworks, coordination polymers etc.), zeolites (both of natural or synthetic origin), clays (e.g. bentonite) or salts (e.g. alkaline earth metal based carbonates, sulphates etc.). It is understood that this list is not limitative. With heterogeneous is meant that no significant or no substantial dissolution of ruthenium in the product phase can be measured by elemental analysis of the hexahydro-iso-alpha-acid product phase. More in particular, “no significant or no substantial dissolution of the ruthenium catalyst” is in the meaning that the product phase is essentially free of ruthenium. Preferably, less than 0.01%, more preferably less than 0.001% of the ruthenium present in the catalyst can be found in the hexahydro-iso-alpha-acid product phase, as measured by elemental analysis.
[0037] Next to ruthenium, also one or more other (noble) metals can be present, for example Ag, Au, Co, Cu, Ir, Ni, Pd, Pt and Rh. Again, it is understood that this list is not limitative. These additional (noble) metals can be present as a separate phase, or a mixed phase, or as an alloy with ruthenium. The ruthenium containing catalyst can also be combined with another heterogeneous hydrogenation catalyst based on the aforementioned (noble) metals. Ruthenium can be present in the ruthenium containing hydrogenation catalyst in its metallic state or as a hydroxide or an oxide. The ruthenium fraction or clusters present in the ruthenium containing hydrogenation catalyst (as they occur on the supporting material) have a particle size distribution varying between 1 nm and 1000 nm, preferably between 1.5 nm and 100 nm, more preferably between 2 nm and 25 nm, as determined by transmission electron microscopy.
[0038] The ruthenium containing hydrogenation catalyst can be used in a molar ratio of iso-alpha-acid (or the tetrahydro-iso-alpha-acid) to the ruthenium fraction of the hydrogenation catalyst varying between 1 and 2000, more preferably between 10 and 500, and most preferably 20 and 200.
[0039] In yet another embodiment of the present invention, the hydrogenation of iso-alpha-acids (or tetrahydro-iso-alpha-acids) to hexahydro-iso-alpha-acids catalyzed by a heterogeneous ruthenium containing catalysts occurs at moderate temperatures of at least 293 K.
[0040] Preferably, the reaction mixture is kept at a reaction temperature in the range of 293 K to 398 K, and more preferably between 333 K and 373 K, most preferably between 343 K and 363 K. The reaction mixture is maintained at the preferred temperature for a reaction time which is in the range of 0.1 to 48 hours, more preferably in the range of 0.5 to 24 hours, most preferably in the range of 1 to 12 hours. During the hydrogenation reaction, an atmosphere containing hydrogen gas is maintained above the reaction mixture. Either pure hydrogen gas can be used or alternatively hydrogen gas mixed with another gas, particularly an inert gas like nitrogen, helium, argon, carbon dioxide or a mixture thereof. Partial pressures of hydrogen can vary between 0.02 and 10.0 MPa. More preferably the partial hydrogen pressure is in the range of 0.1 to 5.0 MPa, and most preferably between 0.2 and 2.0 MPa.
[0041] In another embodiment, organic molecules can be used as the hydrogen source in a process well known as transfer hydrogenation, as described in Heterogeneous Catalytic Transfer Hydrogenation and Its Relation to Other Methods for Reduction of Organic Compounds (R. A. W. Johnstone et al., Chemical Reviews 85 (1985) 129-170).
[0042] The heterogeneous ruthenium containing catalyst can be used in solvent-free conditions. Alternatively, water, carbon dioxide and organic solvents (e.g. methanol, ethanol, 1-propanol, 2-propanol or mixtures of those alcohol solvents) or a mixture thereof can be used as reaction medium.
[0043] Furthermore, the heterogeneous ruthenium containing catalyst can be separated from the reaction medium by means of simple centrifugation, filtration, decantation, or by other liquid-solid separation techniques thus allowing recycling of the catalyst.
[0044] The hydrogenation process can be conducted in a batch reactor whereby the ruthenium containing catalyst and the iso-alpha-acid (or tetrahydro-iso-alpha-acid) containing feed are loaded into the batch reactor at the beginning of the hydrogenation reaction. In another embodiment, the hydrogenation catalyst is used as a fixed bed in a tubular reactor and the iso-alpha-acid (or tetrahydro-iso-alpha-acid) containing feed is pumped through the reactor which allows the direct collection of the hexahydro-iso-alpha-acid product at the outlet of the reactor. Also other reactor and process designs that are generally known to people skilled in heterogeneous catalysis can be used. A non-limiting list of such reactor set-ups can be found in Applied Heterogeneous Catalysis (J.-F. Lepage et al., Institut Frçais du Pétrole, Editions Technip, 1987).
[0045] After high conversion of the iso-alpha-acid (or the tetrahydro-iso-alpha-acid) reactant in solvent-free conditions, the hexahydro-iso-alpha-acid product can be isolated as an organic liquid phase by any unit operation that is suitable for solid-liquid separations. Preferred techniques are centrifugation or filtration of the heterogeneous ruthenium containing catalyst, or decantation of the liquid layer. In case the hydrogenation reaction is performed in the presence of solvents, the solid-liquid separation allows to obtain solutions of the hexahydro-iso-alpha-acid product in water and/or organic solvents like ethanol. It is an advantage of the present invention, in the case of the solvent-free hydrogenation process, that no additional work-up operations are required, such as extraction and evaporation processes to obtain highly pure hexahydro-iso-alpha-acids as a product phase.
[0046] It is understood that the hydrogenation reaction according to the present invention is carried out without the need for an additional reduction step to obtain hexahydro-iso-alpha-acids, such as is the case in the methods to obtain hexahydro-iso-alpha-acids from iso-alpha-acids described in the prior art. Specifically, in the prior art hexahydro-iso-alpha-acids are obtained either (i) by alkali metal borohydride reduction of iso-alpha-acids to form dihydro-iso-alpha-acids, followed by (e.g. Pd catalyzed) hydrogenation of said dihydro-iso-alpha-acids to hexahydro-iso-alpha-acids or (ii) by (e.g. Pd catalyzed) hydrogenation of iso-alpha-acids to tetrahydro-iso-alpha-acids, followed by alkali metal borohydride reduction of said tetrahydro-iso-alpha-acids to form hexahydro-iso-alpha-acids. Thus, it is an advantage of the present invention that the obtained hexahydro-iso-alpha-acids are essentially free of inorganic compounds originating from an inorganic reducing agent, such as borohydride or aluminium hydride based reducing agents. Particularly, the obtained hexahydro-iso-alpha-acids are essentially free of boron species originating from borohydride based reduction reactions.
[0047] Another object of the present invention provides a hexahydro-iso-alpha-acid composition, obtainable by the method according to the present invention without a reduction reaction with an inorganic reductant, such as alkali metal borohydride (e.g. sodium or potassium borohydride) or alkali metal aluminium hydride (e.g. lithium aluminium borohydride). Said hexahydro-iso-alpha-acid composition comprises at least 50, 60, 70, 80, 85 or 90 weight % hexahydro-iso-alpha-acids, expressed on total mass of alpha-acids, iso-alpha-acids and (hydrogenated and/or reduced) derivatives thereof, and is essentially free of inorganic compounds originating from an inorganic reducing agent. More preferably, said hexahydro-iso-alpha-acid composition is essentially free of boron species originating from borohydride based reduction reactions. More in particular, “essentially free of boron species” is in the meaning that said composition comprises less than 50, 40, 30, 20, 10 or 5 ppm boron as measured by elemental analysis.
[0048] The details of the invention will be explained below with reference to the Examples:
Example 1
Solvent-Free Hydrogenation of Iso-Alpha-Acids with Ru/C Catalyst
[0049] All hydrogenation experiments were performed in triplicate for statistical reliability. The starting composition of the iso-alpha-acid reactant was >96% iso-alpha-acids; essentially no reduced iso-alpha-acids were present in the process feed, the alpha-acid content was <1 and the beta-acid content was <3%. 0.04 g of 5% Ru/C catalyst 0.02 mmol Ru), with a mean Ru particle size of 2 nm (as determined by transmission electron microscopy), was added to 0.36 g of iso-alpha-acid feed (≈1 mmol iso-alpha-acids). Next, the reaction mixture was stirred and heated to 333 K, 348 K or 363 K for varying reaction times. All reaction vessels were pressurized with 0.8 MPa hydrogen gas. After the hydrogenation reaction, the powder catalysts were separated from the reaction mixture by centrifugation.
[0050] The sample analyses were performed by means of an HPLC device equipped with a binary pump, vacuum degasser, autosampler, column thermostat, and diode array detector. Two Zorbax Extend C18 columns (150 mm length×4.6 mm inner diameter, packed with 5 μm particles) were used in series. The mobile phase consisted of 5 mM ammonium acetate in 20% (v/v) ethanol adjusted to a pH of 9.95 with ammonia (A solvent) and a mixture consisting of 60% acetonitrile (v/v) and 40% ethanol (v/v) (B solvent). The flow rate was set at 0.4 mL/min and solvent gradient elution was performed: 0-12 min: 0-16% B, 12-14 min: 16-25% B, 14-44 min: 25-40% B, 44-54 min: 40-60% B, 54-64 min: 60-90% B, 64-70 min: 90-100% B. The column temperature was maintained at 308 K. 100 μL volumes of filtered samples were injected. The UV detection was performed at 256 nm for the iso-alpha-acid reactants and the derived reduced iso-alpha-acid products, particularly dihydro-iso-alpha-acids, tetrahydro-iso-alpha-acids and hexahydro-iso-alpha-acids. The samples from the solvent-free hydrogenation experiments were analyzed after addition of 1 mL ethanol.
[0051] At a reaction temperature of 333 K, 0.36 g of iso-alpha-acids was converted with 0.04 g of 5% Ru/C catalyst (molar reactant:suthenium ratio=50) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% alter 24 h (Table 1, entry 1). In the control experiment performed at 333 K without addition of the 5% Ru/C catalyst, <1% of the iso-alpha-acid reactant was converted after a 24 h reaction time (Table 1, entry 2). In an experiment identical to that of entry 1, but conducted for 20 h at 348 K, also a >90% hexahydro-iso-alpha-acid yield was obtained (Table 1, entry 3). At a reaction temperature of 363 K, the hexahydro-iso-alpha-acid yield was >90% after 16 h (Table 1, entry 5). The control experiments performed without the 5% Ru/C catalyst at 348 or 363 K did result in a <1% conversion of the iso-alpha-acid reactant (Table 1, entries 4 and 6).
[0052] Other Ru/C catalysts, with larger Ru particle sizes, were also evaluated. It was observed that 5% Ru/C catalysts characterized by larger mean Ru cluster particle sizes (3 nm-9 nm) required longer reaction times to obtain the >90% hexahydro-iso-alpha-acid yield level, but the same high selectivity to hexahydro-iso-alpha-acids was observed for these Ru catalysts.
[0053] It was also observed that, using the 5% Ru/C catalyst, the alpha-acids and beta-acids, present in low concentration in the iso-alpha-acid containing feed, were hydrogenated to respectively tetrahydro-alpha-acids and hexahydro-beta-acids.
[0000]
TABLE 1
Solvent-free hydrogenation of iso-alpha-acids with Ru/C catalyst
conversion
of
selectivity to
reaction
reaction
iso-alpha-
hexahydro-
temperature
time
catalyst
acids
iso-alpha-acids
entry 1
333 K
24 h
5% Ru/C
>99%
>90%
entry 2
333 K
24 h
/
<1%
/
entry 3
348 K
20 h
5% Ru/C
>99%
>90%
entry 4
348 K
20 h
/
<1%
/
entry 5
363 K
16 h
5% Ru/C
>99%
>90%
entry 6
363 K
16 h
/
<1%
/
Reaction conditions: molar reactant:ruthenium ratio = 50; 0.36 g reactant; 0.04 g catalyst.
Example 2
Solvent-Free Hydrogenation of Iso-Alpha-Acids with Ru/Al 2 O 3 Catalyst
[0054] The hydrogenation experiments were performed as described in Example 1, except for the type and amount of Ru containing catalyst. Here 0.08 g of 5% Ru/Al 2 O 3 , with a mean Ru particle size of 3 nm, was used instead of 0.04 g of 5% Ru/C applied in Example 1.
[0055] The sample analyses were performed as described in Example 1.
[0056] At a reaction temperature of 333 K, 0.36 g of iso-alpha-acids was converted with 0.08 g of 5% Ru/Al 2 O 3 catalyst (molar reactant:ruthenium ratio=25) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 24 h (Table 2, entry 1). Use of higher temperatures (348 K and 363 K instead of 333 K) allows shortening the reaction times required to achieve a >90% hexahydro-iso-alpha-acid yield, as described in entries 2 and 3 of Table 2.
[0057] It was observed that, using the 5% Ru/Al 2 O 3 catalyst, the alpha-acids and beta-acids, present in low concentration in the process feed, were hydrogenated to respectively tetrahydro-alpha-acids and hexahydro-beta-acids.
[0000]
TABLE 2
Solvent-free hydrogenation of iso-alpha-acids with Ru/Al 2 O 3 catalyst
conversion
selectivity to
reaction
reaction
of iso-
hexahydro-
temperature
time
catalyst
alpha-acids
iso-alpha-acids
entry 1
333 K
24 h
5% Ru/
>99%
>90%
Al 2 O 3
entry 2
348 K
20 h
5% Ru/
>99%
>90%
Al 2 O 3
entry 3
363 K
16 h
5% Ru/
>99%
>90%
Al 2 O 3
Reaction conditions: molar reactant:ruthenium ratio = 25; 0.36 g reactant; 0.08 g catalyst.
Example 3
Hydrogenation of Iso-Alpha-Acids in Water with Ru/C Catalyst
[0058] The starting composition of the iso-alpha-acid feed was 5 weight % iso-alpha-acids (present as potassium isohumulate salts) dissolved in water; essentially no reduced iso-alpha-acids were present in the process teed, the alpha-acid content was <1% and the beta-acid content was <1% on (alpha-acid+iso-alpha-acid+beta-acid) mass basis. 0.08 g of 5% Ru/C catalyst (≈0.04 mmol Ru) was added to 0.36 g of iso-alpha-acids (≈1 mmol iso-alpha-acids) dissolved in water. Next, the reaction mixture was stirred and heated to 333 K, 348 K or 363 K for varying reaction times. All reaction vessels were pressurized with 1.6 MPa hydrogen gas. After the hydrogenation reaction, the powder catalysts were separated from the reaction mixture by filtration using 5 μm filters.
[0059] The sample analyses were performed as described in Example 1, except for the sample post-treatment. The reaction samples were analyzed as such, without dilution in ethanol.
[0060] At a reaction temperature of 333 K, 0.36 g of iso-alpha-acids dissolved in water was converted with 0.08 g of 5% Ru/C catalyst (molar reactant:ruthenium ratio=25) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 24 h (Table 3, entry 1). In experiments identical to that of entry 1, but carried out at temperatures of 348 K and 363 K, also a >90% hexahydro-iso-alpha-acid yield was obtained after respectively 20 h and 16 h (Table 3, entries 3 and 5). In the control experiments performed at 333 K, 348 K and 363 K without addition of the 5% Ru/C catalyst, <1% of the iso-alpha-acid reactant dissolved in water was converted (Table 3, entries 2, 4 and 6).
[0061] Hydrogenation processes analogous to entries 1, 3 and 5 of Table 3 were also performed with the 5% Ru/C catalyst pretreated by holding the catalyst under flowing hydrogen gas at 363 K for 1 h prior to application in the hydrogenation process. The catalytic performance of the pretreated 5% Ru/C catalyst was similar to that of the untreated Ru catalyst.
[0000]
TABLE 3
Hydrogenation of iso-alpha-acids in water with Ru/C catalyst
conversion
of iso-
selectivity to
reaction
reaction
alpha-
hexahydro-
temperature
time
catalyst
acids
iso-alpha-acids
entry 1
333 K
24 h
5% Ru/C
>99%
>90%
entry 2
333 K
24 h
/
<1%
/
entry 3
348 K
20 h
5% Ru/C
>99%
>90%
entry 4
348 K
20 h
/
<1%
/
entry 5
363 K
16 h
5% Ru/C
>99%
>90%
entry 6
363 K
16 h
/
<1%
/
Reaction conditions: molar reactant:ruthenium ratio = 25; 0.36 g reactant; 0.08 g catalyst.
Example 4
Hydrogenation of Iso-Alpha-Acids in Water with Ru/Al 2 O 3 Catalyst
[0062] The hydrogenation experiments and sample analyses were performed as described in Example 3, except for the type and amount of Ru catalyst. Here we use 0.16 g of 5% Ru/Al 2 O 3 .
[0063] At a reaction temperature of 333 K, 0.36 g of iso-alpha-acids dissolved in water was converted with 0.16 g of 5% Ru/Al 2 O 3 catalyst (molar reactant:ruthenium ratio=12.5) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 24 h (Table 4, entry 1). In analogous experiments performed at reaction temperatures of 348 K and 363 K, also a >90% hexahydro-iso-alpha-acid yield was obtained after respectively 20 h and 16 h (Table 4, entries 2 and 3).
[0000]
TABLE 4
Hydrogenation of iso-alpha-acids in water with Ru/Al 2 O 3 catalyst
conversion
of
selectivity to
reaction
reaction
iso-alpha-
hexahydro-
temperature
time
catalyst
acids
iso-alpha-acids
entry 1
333 K
24 h
5%
>99%
>90%
Ru/Al 2 O 3
entry 2
348 K
20 h
5%
>99%
>90%
Ru/Al 2 O 3
entry 3
363 K
16 h
5%
>99%
>90%
Ru/Al 2 O 3
Reaction conditions: molar reactant:ruthenium ratio = 12.5; 0.36 g reactant; 0.16 g catalyst.
Example 5
Hydrogenation of Iso-Alpha-Acids in Ethanol with Ru/C Catalyst
[0064] The starting composition of the iso-alpha-acid feed was 25 weight % iso-alpha-acids dissolved in ethanol; essentially no reduced iso-alpha-acids were present in the process feed, the alpha-acid content was <1% and the beta-acid content was <3% on (alpha-acid+iso-alpha-acid+beta-acid) mass basis. 0.04 g of 5% Ru/C catalyst (≈0.02 mmol Ru) was added to 0.36 g of iso-alpha-acids 1 mmol iso-alpha-acids) dissolved in ethanol. Next, the reaction mixture was stirred and heated to 333 K or 348 K for varying reaction times. All reaction vessels were pressurized with 2.0 MPa hydrogen gas. After the hydrogenation reaction, the powder catalysts were separated from the reaction mixture by centrifugation.
[0065] The sample analyses were performed as described in Example 1, except for the sample treatment prior to HPLC analysis. The reaction samples were analyzed as such, without further dilution in ethanol.
[0066] At 333 K, 0.36 g of iso-alpha-acids dissolved in ethanol was converted with 0.04 g of 5% Ru/C catalyst (molar reactant:ruthenium ratio=50) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% alter 28 h (Table 5, entry 1). In an experiment identical to that of entry 1, but performed at 348 K, a >90% hexahydro-iso-alpha-acid yield was obtained after respectively 24 h (Table 5, entry 3). In the control experiments performed at 333 K and 348 K without addition of the Ru/C catalyst, <1% of the iso-alpha-acid reactant was converted (Table 5, entries 2 and 4).
[0000]
TABLE 5
Hydrogenation of iso-alpha-acids in ethanol with Ru/C catalyst
conversion
of
selectivity to
reaction
reaction
iso-alpha-
hexahydro-
temperature
time
catalyst
acids
iso-alpha-acids
entry 1
333 K
28 h
5% Ru/C
>99%
>90%
entry 2
333 K
28 h
/
<1%
/
entry 3
348 K
24 h
5% Ru/C
>99%
>90%
entry 4
348 K
24 h
/
<1%
/
Reaction conditions: molar reactant:ruthenium ratio = 50; 0.36 g reactant; 0.04 g catalyst.
Example 6
Hydrogenation of Iso-Alpha-Acids in Ethanol Catalyst
[0067] The hydrogenation experiments and sample analyses were performed as described in Example 5, except for the type and amount of Ru containing catalyst. Here we use 0.08 g of 5% Ru/Al 2 O 3 .
[0068] At a reaction temperature of 333 K, 0.36 g of iso-alpha-acids dissolved in ethanol was converted with 0.08 g of 5% Ru/Al 2 O 3 catalyst (molar reactant:ruthenium ratio=25) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 28 h (Table 6, entry 1). In an analogous experiment conducted at a reaction temperature of 348 K, a >90% hexahydro-iso-alpha-acid yield was obtained after 24 h (Table 6, entry 2).
[0000]
TABLE 6
Hydrogenation of iso-alpha-acids in ethanol with Ru/Al 2 O 3 catalyst
conversion
selectivity to
reaction
reaction
of iso-
hexahydro-
temperature
time
catalyst
alpha-acids
iso-alpha-acids
entry 1
333 K
28 h
5% Ru/
>99%
>90%
Al 2 O 3
entry 2
348 K
24 h
5% Ru/
>99%
>90%
Al 2 O 3
Reaction conditions: molar reactant:ruthenium ratio = 25; 0.36 g reactant; 0.08 g catalyst.
Example 7
Solvent-Free Hydrogenation of Iso-Alpha-Acids with Ru/C and Pd/C Catalysts
[0069] The starting composition of the iso-alpha-acid reactant was >96% iso-alpha-acids; essentially no reduced iso-alpha-acids were present in the process feed, the alpha-acid content was <1% and the beta-acid content was <3%. 0.04 g of 5% Ru/C catalyst 0.02 mmol Ru) was added to 0.36 g of iso-alpha-acid feed 1 mmol iso-alpha-acids) for the Ru catalyzed iso-alpha-acid hydrogenation experiments. 0.04 g of 5% Pd/C 0.02 mmol Pd) was added to 0.36 g of iso-alpha-acid feed (≈1 mmol iso-alpha-acids) for the Pd catalyzed iso-alpha-acid hydrogenations. Next, the reaction mixture was stirred and heated to 348 K, for a reaction time of 20 h for the hydrogenation experiments with the Ru containing catalyst and for 16 h for the hydrogenation experiments with the Pd based catalyst. All reaction vessels were pressurized with 0.8 MPa hydrogen gas. After the hydrogenation reaction, the powder catalysts were separated from the reaction mixture by centrifugation.
[0070] The sample analyses were performed as described in Example 1.
[0000]
TABLE 7
Solvent-free hydrogenation of iso-alpha-acids
with Ru/C and Pd/C catalysts
selectivity to
conversion of
hexahydro-
reaction time
catalyst
iso-alpha-acids
iso-alpha-acids
entry 1
20 h
5% Ru/C
>99%
>90%
entry 2
16 h
5% Pd/C
>99%
<1%
Reaction conditions: molar reactant:ruthenium ratio = 50; molar reactant:palladium ratio = 50; 0.36 g reactant; 0.04 g catalyst; 348 K.
[0071] At a reaction temperature of 348 K, 0.36 g of iso-alpha-acids was converted with 0.04 g of the 5% Ru/C catalyst (molar reactant:ruthenium ratio=50) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 20 h (Table 7, entry 1). At the same reaction temperature, the same amount of iso-alpha-acid reactants was converted with 0.04 g of the 5% Pd/C catalyst (molar reactant:palladium ratio=50) for >99% with a hexahydro-iso-alpha-acid yield below 1% and a tetrahydro-iso-alpha-acid yield exceeding 90% after 16 h (Table 7, entry 2).
Example 8
Solvent-Free Hydrogenation of Iso-Aloha-Acids with a Combination of Ru/C and Pd/C Catalysts
[0072] The starting composition of the iso-alpha-acid reactant was >96% iso-alpha-acids; essentially no reduced iso-alpha-acids were present in the process feed, the alpha-acid content was <1% and the beta-acid content was <3%. 0.04 g of 5% Ru/C (≈catalyst 0.02 mmol Ru) and 0.04 g of 5% Pd/C 0.02 mmol Pd) were added to 0.36 g of iso-alpha-acid feed (≈1 mmol iso-alpha-acids). Next, the reaction mixture was stirred and heated to 333 K, 348 K or 363 K for varying reaction times. All reaction vessels were pressurized with 0.8 MPa hydrogen gas. After the hydrogenation reaction, the powder catalysts were separated from the reaction mixture by centrifugation.
[0073] The sample analyses were performed as described in Example 1.
[0000]
TABLE 8
Solvent-free hydrogenation of iso-alpha-acids with a combination
of Ru/C and Pd/C catalysts
conversion
selectivity to
of
hexahydro-
reaction
reaction
iso-alpha-
iso-alpha-
temperature
time
catalyst
acids
acids
entry 1
333 K
16 h
5% Ru/C +
>99%
>90%
5% Pd/C
entry 2
348 K
12 h
5% Ru/C +
>99%
>90%
5% Pd/C
entry 3
363 K
8 h
5% Ru/C +
>99%
>90%
5% Pd/C
Reaction conditions: molar reactant:(ruthenium + palladium) ratio = 25; 0.36 g reactant; 0.04 g Ru/C catalyst + 0.04 g Pd/C catalyst.
[0074] At a reaction temperature of 333 K, 0.36 g of iso-alpha-acids was converted with 0.04 g of 5% Ru/C and 0.04 g of 5% Pd/C (molar reactant:(ruthenium+palladium) ratio=25) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 16 h (Table 8, entry 1). In hydrogenation experiments identical to entry 1, but performed at 348 K and 363, also >90% hexahydro-iso-alpha-acid yields were obtained after respectively 12 h and 8 h (Table 8, entries 2 and 3).
Example 9
Hydrogenation of Iso-Alpha-Acids, Dihydro-Iso-Alpha-Acids and Tetrahydro-Iso-Alpha-Acids in Water with Ru/C Catalyst
[0075] The starting composition of the reactant was 5 weight % iso-alpha-acids, or 5 weight % dihydro-iso-alpha-acids, or 5 weight % tetrahydro-iso-alpha-acids (all present in the form of the derived potassium salts) dissolved in water; essentially no other (reduced) iso-alpha-acids than the intended reactants (respectively iso-alpha-acids, dihydro-iso-alpha-acids and tetrahydro-iso-alpha-acids) were present in the process feed, the alpha-acid content was <1% and the beta-acid content was 1% on (alpha-acid+(reduced) iso-alpha-acid+beta-acid) mass basis. 0.08 g of 5% Ru/C catalyst (≈0.04 mmol Ru) was added to 0.36 g of iso-alpha-acids (≈1 mmol iso-alpha-acids), or to 0.36 g of dihydro-iso-alpha-acids (≈1 mmol dihydro-iso-alpha-acids), or to 0.36 g of tetrahydro-iso-alpha-acids (≈1 mmol tetrahydro-iso-alpha-acids) dissolved in water. Next, the reaction mixture was stirred and heated to 348 K for varying reaction times. All reaction vessels were pressurized with 1.6 MPa hydrogen gas. After the hydrogenation reaction, the powder catalysts were separated from the reaction mixture by filtration.
[0076] The sample analyses were performed as described in Example 1, except for the sample post-treatment. The reaction samples were analyzed as such, without dilution in ethanol.
[0077] At a reaction temperature of 348 K, 0.36 g of iso-alpha-acids dissolved in water was converted with 0.08 g of 5% Ru/C catalyst (molar reactant:ruthenium ratio=25) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 20 h (Table 9, entry 1). At a reaction temperature of 348 K, 0.36 g of dihydro-iso-alpha-acids dissolved in water was converted with 0.08 g of 5% Ru/C catalyst (molar reactant:ruthenium ratio=25) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 12 h (entry 3). In the control experiment without the 5% Ru/C catalyst, <1% of the dihydro-iso-alpha-acid reactant was converted (entry 4). At a reaction temperature of 348 K, 0.36 g of tetrahydro-iso-alpha-acids dissolved in water was converted with 0.08 g of 5% Ru/C catalyst (molar reactant:ruthenium ratio=25) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% alter 16 h (entry 5). In the control experiment without the 5% Ru/C catalyst, <1% of the tetrahydro-iso-alpha-acid reactant was converted (entry 6).
[0078] The reaction time dependency of the conversion of the dihydro-iso-alpha-acids and tetrahydro-iso-alpha-acids, both leading to the hexahydro-iso-alpha-acid products, is reported in FIG. 2 .
[0000]
TABLE 9
Hydrogenation of iso-alpha-acids, dihydro-iso-alpha-acids and
tetrahydro-iso-alpha-acids in water with Ru/C catalyst
selectivity to
conversion
hexahydro-
reaction
of
iso-alpha-
Reactant
time
catalyst
reactant
acids
entry 1
iso-alpha-acid
20 h
5% Ru/C
>99%
>90%
entry 2
iso-alpha-acid
20 h
/
<1%
/
entry 3
dihydro-
12 h
5% Ru/C
>99%
>90%
iso-alpha-acid
entry 4
dihydro-
12 h
/
<1%
/
iso-alpha-acid
entry 5
tetrahydro-
16 h
5% Ru/C
>99%
>90%
iso-alpha-acid
entry 6
tetrahydro-
16 h
/
<1%
/
iso-alpha-acid
Reaction conditions: molar reactant:ruthenium ratio = 25; 0.36 g reactant; 0.08 g catalyst; 348 K.
Example 10
Recycling of the Ru/C Catalyst in the Solvent-Free Hydrogenation of Iso-Alpha-Acids
[0079] The hydrogenation experiments and sample analyses were performed as described in Example 1. After separation of the Ru/C catalyst powder from the reaction mixture by centrifugation, the Ru/C catalyst was reused in a next iso-alpha-acid hydrogenation.
[0080] At a reaction temperature of 333 K, 0.36 g of iso-alpha-acids was converted with 0.04 g of 5% Ru/C catalyst (molar reactant:ruthenium ratio=50) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 24 h (Table 10, entry 1). At the same reaction temperature, 0.36 g of iso-alpha-acids was converted with 0.04 g of the recycled 5% Ru/C catalyst (molar reactant:ruthenium ratio=50) to hexahydro-iso-alpha-acids with a hexahydro-iso-alpha-acid yield of >90% after 24 h (Table 10, entry 2). Also in the case of higher reaction temperatures (348 K and 363 K), the performance of the 5% Ru/C catalyst proved stable upon recycling both in terms of hydrogenation activity and selectivity, as demonstrated in Table 10, entries 3 to 6.
[0000]
TABLE 10
Recycling of the Ru/C catalyst in the solvent-free
hydrogenation of iso-alpha-acids
conversion
selectivity to
reaction
reaction
catalyst
of iso-alpha-
hexahydro-
temperature
time
use
acids
iso-alpha-acids
entry 1
333 K
24 h
no. 1
>99%
>90%
entry 2
333 K
24 h
no. 2
>99%
>90%
entry 3
348 K
20 h
no. 1
>99%
>90%
entry 4
348 K
20 h
no. 2
>99%
>90%
entry 5
363 K
16 h
no. 1
>99%
>90%
entry 6
363 K
16 h
no. 2
>99%
>90%
Reaction conditions: molar reactant:ruthenium ratio = 50; 0.36 g reactant; 0.04 g 5% Ru/C catalyst.
Example 11
Hydrogenation of Iso-Alpha-Acids with Ru/C Catalyst: Elemental Analysis on Reaction Products
[0081] The elemental analyses of the reaction samples were performed by means of an ICP-AES device. The spectral line used for the detection of Ru was 240.272 nm. Prior to elemental analysis of the reaction samples, a calibration curve was determined to relate the Ru concentration to the intensity of the detection signal. The samples from the solvent-free hydrogenation experiments, the hydrogenation experiments in water and the hydrogenation experiments in ethanol were analyzed after 100-fold dilution in water.
[0082] Under the conditions of the hydrogenation experiments in solvent-free conditions, in water medium and in ethanol medium, no leaching of Ru into the reaction medium was detected by ICP-AES from the Ru/C catalyst. In all cases, there was less than 0.01% of Ru dissolved from the 5% Ru/C catalyst into the product phase in the course of the hydrogenation experiments.
[0083] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and Examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims: | The invention relates to a process for the production of hexahydro-iso-alpha-acids starting from iso-alpha-acids (or tetrahydro-iso-alpha-acids) in which iso-alpha-acids (or tetrahydro-iso-alpha-acids) are mixed with a heterogeneous ruthenium containing catalyst, that catalyzes the hydrogenation from iso-alpha-acids or tetrahydro-iso-alpha-acids to hexahydro-iso-alpha-acids, either in solvent-free conditions, or in the presence of a solvent phase (e.g. carbon dioxide, water, ethanol or another organ-ic solvent, or mixtures thereof), and in the absence or presence of other hop compounds (such as beta-acids). The resulting mix-ture is then subjected to a temperature at which the iso-alpha-acid (or tetrahydro-iso-alpha-acid) containing reaction medium is sufficiently low in viscosity to allow easy mixing with the heterogeneous ruthenium containing catalyst and held under a hydrogen containing atmosphere (either pure hydrogen gas or mixed with an inert gas) for a reaction tune sufficient to effect high conver-sion of the iso-alpha-acid (or tetrahydro-iso-alpha-acid) reactant into the hexahydro-iso-alpha-acid product. The molar ratio of iso-alpha-acid or tetrahydro-iso-alpha-acid to ruthenium varies between 1:1 and 2000:1. After the hydrogenation process, the hetero-geneous ruthenium containing catalyst can be separated from the hexahydro-iso-alpha-acid product phase by centrifugation, filtra-tion, decantation or other liquid-solid separation techniques. The hydrogenation process can be performed batch-wise or alterna-tively in continuous mode. | 2 |
The present invention concerns cathodic blocks having a low voltage drop, which are intended for tanks for the production of aluminium by the electrolysis of alumina which is dissolved in molten cryolite, using the Hall-Heroult process. It also concerns cathodes formed from such modular cathodic blocks.
STATEMENT OF THE PRIOR ART
The cathode of a Hall-Heroult electrolysis tank is formed by the juxtaposition of an assembly of carbonaceous blocks which at their lower base are provided with one (or sometimes two) open grooves into which steel bars of square, rectangular or circular section are sealed, generally by casting iron therein, the connecting conductors between the successive tanks forming a series being connected to the steel bars. The blocks are generally joined by a carbonaceous paste referred to as a luting or brasquing paste which is a poor conductor of current and which is several centimeters in thickness.
The paste must be impervious with respect to the liquid aluminium which is deposited by electrolysis upon the carbonaceous blocks. Therefore, the electrical current flows in the following order through a layer of liquid aluminium, a carbonaceous portion, the bar-block sealing means and the steel bars, and passes into the conductors for connection to the following tank.
Each combination of materials results in a contact overvoltage which depends on the condition of assembly and the surface areas involved. That is particularly true in regard to the contact between the carton component and the sealing means, which is referred to as the sealing means contact.
The total voltage drop may therefore be broken down into three predominant components:
the voltage drop in the carbon,
the voltage drop at the sealing means, and
the voltage drop in the steel bar.
In order to reduce that voltage drop, it is known to use carbonaceous blocks of low electrical resistivity.
At the present time, most of the producers of cathodic blocks are proposing blocks which are referred to as "semi-graphite" blocks, being produced from a carbonaceous paste in which grains of anthracite have been replaced by grains of graphite, and "semi-graphited" blocks which are produced from a conventional carbonaceous paste but with baking at elevated temperature (>2000° C.) so as to cause partial graphitisation of the block in the mass thereof. That substantially increases the electrical conductivity of the blocks. However, that type of block suffers from the defect of increasing electrical current distortion in the upper layer of liquid aluminium as a result of more severe inclination of the lines of current in the liquid aluminium, hence increasing magnetic turbulence of the other layer of liquid aluminium, which detrimentally affects the hydrodynamic stability of the electrolysis apparatus.
In order to correct that defect, it is possible to use the construction referred to as "sandwich blocks", in which a portion is formed for example from carbonaceous paste with anthracite grains and another portion is formed from semi-graphite or semi-graphited carbonaceous paste, with a higher level of electrical conductivity.
In order to increase the active surface area of the cathode, it has also been proposed that the method which involves joining the blocks by means of a luting or brasquing paste (which is a poor electrical conductor) should be replaced by glueing by means of a conductive glue based on graphite and thermosetting resins. That procedure has the quadruple advantage of increasing the total conductive surface area, permitting electrical transfers between two adjacent blocks, reducing the emission of tars when the carbonaceous joining material is set in position, and improviding the imperviousness of the assembly.
In order to reduce the total voltage drop, it is also known to increase the section of the steel bar, at least in the region thereof which is sealed into the carbon, while retaining a normal or reduced section at the point at which the bar passes through the outside portion of the thermal insulation of the tank, in order to avoid excessive thermal leakage.
However, the extent of such an action is necessarily limited as the thickness of carbon forming the side portions of the groove must be sufficient mechanically to resist the stresses due to thermal expansion of the cathodic bar and the sealing means thereof, when the tank is being brought into operation. The shape of the section of the sealed portion may be either circular or rectangular.
In order to reduce the voltage drop, use is also made of carbonaceous blocks having two narrow grooves, which have the advantage of multiplying the contact surface area with respect to the sealing means, without making the block too fragile when it is subjected to the thermal operating stresses of the electrolysing apparatus. It is then necessary to provide a minimum spacing between the edge of the block and the closest groove, and that limits the possible cross section of the steel bars.
Irrespective of the construction adopted and irrespective of the shape and dimensions of the blocks and the iron bars which are sealed into the blocks, the cathode is always constructed by arranging the blocks in parallel relationship to the small side of the metal casing so that the cathodic outputs (ends of the bars which extend to the exterior of the casing and to which the inter-tank connecting conductors are connected) are always on the long side of the tank, whether the tanks are disposed lengthwise or transversely with respect to the axis of the series of tanks.
STATEMENT OF PROBLEM
At the present time, producers of aluminium are trying to increase the unit power of electrolysis tanks with a view in particular to increasing the outputs thereof, reducing the capital investment costs, and facilitating integral automation of the operating procedure. The level of 200,000 amperes has already been greatly exceeded, and it is highly probable that a level of 400,000 amperes will be reached before the end of the nineteen eighties.
In parallel therewith, a substantial effort is being made to reduce the levels of power consumption of the tank, in particular by reducing the ohmic drops in the cathode.
The construction of cathodes with a low voltage drop for tanks of that kind of power requires fresh solutions which cannot be achieved simply by extrapolation from the presentday solutions. In fact, it is known that the service life of a tank is closely dependent on the quality of its cathode as most of the occasions on which tanks are prematurely taken out of service are due to metal and electrolyte infiltrating into the sub-cathodic space.
STATEMENT OF THE INVENTION
The present invention is based on a novel design of cathodes which may be referred to as being "modular" as, by acting on the number of modules, it can be adapted to any size of tank which is an integral multiple of the dimensions of the module.
The invention concerns a carbonaceous cathodic block having a low voltage drop, which is intended for tanks for the production of aluminium by electrolysis using the Hall-Heroult process, such tanks comprising a parallelepipedic metal casing supporting a cathode on which the layer of liquid aluminium is formed, said cathode being formed by the juxtaposition of parallelepipedic carbonaceous blocks of elongate shape, having a ratio in respect of the length of their major axis to their width that is at least equal to two, and wherein there is cut at least one groove into which is sealed a steel bar disposed in parallel relationship to the short side of the casing and which connects to at least one cathodic collector, characterised in that the sealing grooves are cut in a direction which is perpendicular to the major axis of the block which is itself disposed in parallel relationship to the long side of the casing.
By virtue of a first cathodic block being associated with at least one second block, by glueing on a large side face thereof, it is possible to produce a cathodic demi-module whose width corresponds to half the width of the cathode.
By associating two demi-modules together by a means such as glueing, it is possible to provide a cathodic module whose width corresponds to the width of the cathode.
The same invention also concerns a carbonaceous cathode for the production of aluminium using the Hall-Heroult process characterised in that it is formed by the juxtaposition in the same plane of at least two cathodic modules, the connection between the successive modules being provided by a known means such as a join of carbonaceous paste.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of part of a cathode of an electrolysis tank according to the prior art.
FIG. 2 is a plan view of part of the cathode of an electrolysis tank according to the invention.
FIG. 3 is a plan view of a part of an electrolysis tank according to an alternative embodiment of the invention.
FIG. 4A is a plan view of an arrangement of cathodic blocks in an electrolysis tank according to the prior art.
FIG. 4B is a plan view of the arrangement of cathodic blocks in an electrolysis tank according to the invention.
FIGS. 5A and 5B are side cross-sectional views of embodiments of cathodic blocks according to the prior art.
FIG. 5C is a side cross-sectional view of a cathodic block according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagrammatic plan view of part of the cathode of an electrolysis tank, using the presentday construction. The cathodic blocks 1 are disposed in parallel relationship to the short side 2 of the metal casing which supports the cathode of the electrolysis tank. The blocks are of parallelepipedic shape, being elongate with a long or major axis as indicated by AA', the height h and the width l thereof generally being of the order of 300 to 700 mm, while their length is of the order of 2 meters and above. The length/width ratio, in most cases, is higher than 2, and may reach from 4 to 8. Height and width are often in a ratio which is not substantially different from 1.
In the particular construction shown in FIG. 1, each block 1 comprises two bars 3 which in practice are often each formed by two bar halves 3A and 3B which may or may not be contiguous or joined in their central portion 4. At their end 5, on the exterior, the cathodic bars are connected to one or more lateral conductors as indicated at 6, which are connected to the anodic structure of the next following tank in the series. The bars are sealed into one or two longitudinal grooves 7 of the block 1, in most cases by means of cast iron.
The successive cathodic blocks are sealed by a joint formed by luting or brasquing paste 8 which is tamped into position in the hot condition and which seals the assembly of the cathode with respect to infiltrating liquid aluminium and molten electrolyte, the service life of the tank being closely dependent on the sealing effect produced.
In accordance with the invention (as shown in FIG. 2 and the following figures of drawings), the cathodic blocks 10A-D are disposed in such a way that their major axis AA' is parallel to the long side 11 of the casing and to its major axis XX'. The cathodic bars 3 and the outputs 5, as well as the collector 6, are disposed in the same manner, but the grooves 12 are now cut transversely in the cathodic block, parallel to the short side thereof and therefore perpendicularly to its major axis AA'.
Each "cathodic demi-module" is formed by the association of two blocks 10A and 10B which have been previously assembled together by a means such as adhesive as indicated at 9, the cathodic bars being set in position and sealed in place by means of the usual processes such as sealing with cast iron or, more rarely, carbonaceous paste. The juxtaposition of two identical demi-modules symmetrically with respect to the major axis of the tank constitutes a first cathodic module. The two half-modules 10A-10B and 10C-10D are joined together and grouted in the usual fashion using luting or brasquing paste 13 or preferably by adhesive. The grouting operation may be carried out before or after the cathode construction has been set in position in the casing. The first cathodic module is then completed by a certain number of identical modules with are grouted together using the luting or brasquing paste 8, depending on the type of tank. A cathode for a 180,000 ampere tank for example may be formed from three successive modules. Although the foregoing description sets forth demi-modules which are each formed by two blocks, that example does not constitute a limitation on the invention. It is possible to envisage semi-manufactured products formed by two blocks of unequal widths, or three blocks of equal or unequal widths, although in contrast the height and the length must be the same in all cases.
Taking the above-indicated basic principle, the invention can be carried into effect in a plurality of different ways. Each of the two blocks forming a cathodic demi-module, as indicated at 10A and 10B, may be of identical composition, that is to say, produced from the same carbonaceous paste, or of different composition, so as to impart particular properties to one of the blocks, for example a different level of thermal or electrical conductivity.
For example, the outside block 10A may be of conventional type (pitch+grains of anthracite) which, at 900° C., has an electrical resistivity value of the order of 4.4×10 -3 Ωcm and a thermal conductivity value λ of the order of 0.03 W/cm/°C., whereas the inner block 10B may be of the "semi-graphite" type, which at 900° C. has an electrical resistivity value of 2.8×10 -3 Ωcm and a thermal conductivity value λ of 0.23 W/cm°C.
In an alternative form as shown in FIG. 3, the outer block 10A may itself be formed in two parts, the outer part 10E being of a material with a relatively low level of thermal conductivity so as to reduce the flow of heat which is drained off to the exterior by the carbonaceous blocks and thus to improve the thermal balance sheet of the electrolysing apparatus.
Finally, the sections of the sealing grooves 12 may all be of equal width or some thereof, in particular those at the ends, may be different, for example in order to provide a constant spacing between the holes in the side wall of the casing, through which the cathodic bars issue.
Moreover, over a part at least of the surface of the cathodic blocks forming the cathode, it is possible to incorporate a substance which enables them to be wetted with the liquid aluminium. Such incorporation may be at the surface or it may involve all or part of the cathodic blocks.
It is known in particular from the publication by K. BILLEHAUG and H. A. OYE, "ALUMINIUM" 56, 1980, pages 642 to 648 (April 1980) and pages 713 to 718 (November 1980) that refractory compounds referred to as "RHM" (Refractory Hard Metals) and more particularly titanium diboride TiB 2 are both wetted with liquid aluminium and also subject to very little attack by that metal at temperatures of 930° to 960° C.
Thus, it is possible for the surface of the cathodic blocks to be totally or partially covered with plates or other elements of pure TiB 2 or a composite material containing at least 30% of TiB 2 ; alternatively, using known means, it is possible to produce a deposit of TiB 2 or a TiB 2 -base composite over all or part of the cathodic surface; alternatively again, it is possible to introduce TiB 2 and/or a RHM compound into the carbonaceous material forming the cathodic blocks or at least the upper portion of the cathodic blocks which is in contact with the liquid aluminium, the proportion of TiB 2 or RHM compound being at least equal to 30%, which is the recognised minimum for producing the wetability effect. In that way it is possible to stabilise the layer of liquid aluminium and substantially to reduce the anode-cathode spacing and therefore the voltage drop in the electrolysis bath, which gives a correlated reduction in specific energy in kilowatts hour per tonne of aluminium produced.
ADVANTAGES OBTAINED BY THE INVENTION
A very large number of advantages are attained by carrying the invention into effect, as may be put forward in the following manner:
1. The useful cathodic surface area is increased by replacing joints made up of luting or brasquing paste, from 30 to 40 mm in width and providing poor electrical conductivity, with glued joints of very small thickness, of the order of a millimeter.
2. It is now possible to reconcile a substantial steel section with a substantial carbon-steel contact surfacea area, which was not the case in accordance with the prior art.
It will be seen from FIG. 5 which shows, on a scale of about 1/20, vertical sections of cathodic blocks, in accordance with the prior art as indicated at 5A and 5B, and in accordance with the invention as indicated at 5C, that, for a given vertical section, the dimensions go from a sealing contact length of 36.8 dm and a steel and cast iron section of 17.16 dm2 for the block shown at 5A, to a contact length of 29.2 dm and a section of 26.4 dm2 in the case of block 5B, and to a contact length of 41.6 dm and a section of 25.08 dm2 in the case of the block indicated at 5C. That results in a very substantial reduction in the ohmic sealing contact drop, combined with a very low level of ohmic drop in the steel bar. It should be noted that that overall gain which was found to be equal to several tens of millivolts, was achieved without rendering the carbon block fragile, the wings or side portions 16 of the blocks, that is to say, the carbon portions remaining between grooves or between a groove and the side of the blocks, still being of the same dimensions. The man skilled in the art is aware that a gain of 10 mV is equivalent to a drop in consumption of from 30 to 35 kWh per tonne of aluminium produced.
3. The novel arrangement of the cathodic blocks makes it possible to produce mixed or "sandwich" blocks in a simple and economical fashion. In the prior art, it was necessary to cut up the blocks 1 and then to assemble the two parts (anthracite and semi-graphite for example) when fitting the cathodes, whereas in accordance with the invention, each mixed block such as 10A=10B is produced by simp1y glueing two blocks of standard dimensions and setting them in position as they stand.
4. The positioning operation requires less labour: the fitting of four blocks (FIG. 1) is replaced by the fitting of two demi-modules (FIG. 2) or a single module which has been pre-assembled by adhesive means.
5. In comparison with the conventional way of glueing together blocks 1 in a transverse configuration, being pushed by means of jacks 14 having a long operating travel (see FIG. 4A), being a difficult operation to carry out as that arrangement causes errors in parallelism to become cumulative, the modular assembly of the invention accommodates substantial inaccuracies which are compensated for by the jointing of brasquing or luting paste as indicated at 8 between adjacent modules (FIG. 4B). In addition, it is sufficient to provide jacks 15 which have a short operating travel, being disposed against the long side of the casing, for pushing against the two demi-modules 5C in the course of glueing thereof to form each cathodic module.
6. By replacing the luting or brasquing paste joins by adhesive or glued joins, the cathode is better sealed with respect to infiltrating molten metal and electrolyte. The importance of the properly sealed nature of the cathode has been pointed out hereinbefore.
7. Finally, the invention is compatible with the use of cathodic surfaces which can be wetted with liquid aluminium.
EXAMPLE OF USE
The invention was carried into practice on a number of tanks of a series operating with a current of 180,000 amperes, with the cathode being formed from demi-modules made up of two "semi-graphite" blocks as shown in FIG. 5C.
Taking coventional tanks with anthracite blocks and taking the tanks which have been modified in accordance with the invention, measurements were taken in respect of the voltage drop in the cathodic system, in the sealing contact and in the cathodic bar, and the results obtained are as follows:
______________________________________PRIOR ACCORDING TOART BLOCKS THE INVENTIONFIG. 5A FIG. 5B BLOCKS FIG. 5C______________________________________Sealing 67 84 59contactBar ohmic 136 88 83dropTOTAL 203 172 142______________________________________
The maximum gain achieved is 61 mV, which corresponds to close to 200 kWh less per tonne of aluminium produced. Half of that gain was achieved by using "semi-graphite" blocks with a lower degree of resistivity, while the other half was attained by using the modular cathodic block invention. | The invention relates to a carbonaceous cathodic block having a low voltage drop, which is intended for tanks for the production of aluminium by electrolysis using the Hall-Heroult process, said tanks comprising a parallelepipedic metal casing supporting a cathode on which the layer of liquid aluminium is formed, said cathode being formed by the juxtaposition of parallelepipedic carbonaceous blocks of elongate shape wherein the ratio of the length of the major axis to the width is at least equal to two and in which there is cut at least one groove into which is sealed a steel bar which is disposed in parallel relationship to the short side of the casing and which connects to at least one cathodic collector, characterized in that the sealing grooves are cut in the direction perpendicular to the major axis of the block which is itself disposed in parallel relationship to the long side of the casing. | 2 |
RELATED APPLICATIONS
This application claims the benefit of U.S. application Ser. No. 13/175,399, filed Jul. 15, 2011, the disclosure of which is hereby incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The invention relates to a methanol production process that includes at least two membrane separation steps, using a hydrogen-selective membrane followed by a carbon dioxide-selective membrane, to improve the efficiency of methanol production from natural gas. Hydrogen recovered during the membrane separation step can be sent for other uses. The process of the invention may debottleneck existing methanol plants, allowing for feed of recycled carbon dioxide into the synthesis loop, resulting in sequestration of the carbon dioxide and production of additional methanol.
BACKGROUND OF THE INVENTION
Methanol, the simplest alcohol, with a chemical formula of CH 3 OH, is a light, volatile, colorless, flammable liquid. A polar liquid at room temperature, methanol finds use as an antifreeze, solvent, fuel, and as a denaturant for ethanol. It is also used for producing biodiesel via a transesterification reaction.
The largest use of methanol, however, is in the manufacture of other chemicals. About forty percent of methanol is converted to formaldehyde, and from there into products as diverse as plastics, plywood, paints, explosives, and permanent-press textiles.
Methanol is also used on a limited basis as fuel for internal combustion engines. The use of methanol as a motor fuel received attention during the oil crises of the 1970's due to its availability, low cost, and environmental benefits. However, due to the rising cost of methanol and its corrosivity to rubber and many synthetic polymers used in the auto industry, by the late 1990s automakers had stopped building vehicles capable of operating on either methanol or gasoline (“flexible fuel vehicles”), switching their attention instead to ethanol-fueled vehicles. Even so, pure methanol is required as fuel by various auto, truck, and motorcycle racing organizations.
In 1923, German chemists Alwin Mittasch and Mathias Pier, working for BASF, developed a process for converting synthesis gas (a mixture of carbon monoxide, carbon dioxide, and hydrogen) into methanol. The process used a chromium and magnesium oxide catalyst and required extremely vigorous conditions—pressures ranging from 50 to 220 bar, and temperatures up to 450° C. A patent (U.S. Pat. No. 1,569,775) covering this process was issued on Jan. 12, 1926.
Modern methanol production has been made more efficient through the use of catalysts (typically copper) capable of operating at lower pressures. The modern low-pressure methanol (LPM) production process was developed by ICI in the late 1960's, with the technology now owned by Johnson Matthey (London), a leading licensor of methanol technology.
The production of synthesis gas (“syngas”) via steam reforming of natural gas is the first step in many processes for methanol production. At low to moderate pressures and at high temperatures around 850° C., methane reacts with steam on a nickel catalyst to produce syngas according to the following reactions:
CH 4 +H 2 O→CO+3H 2 CO+H 2 O→CO 2 +H 2
This process, commonly referred to as “steam methane reforming” (SMR) is highly endothermic, and maintaining reaction temperature by external heating is a critical part of the process.
The syngas is then compressed and reacted on a second catalyst to produce methanol. Today, the most commonly used catalyst is a mixture of copper, zinc oxide, and alumina first used by ICI in 1966. At 50-100 bar and 250° C., it can catalyze the production of methanol from syngas with high selectivity:
CO+2H 2 →CH 3 OH CO 2 +3H 2 →CH 3 OH+H 2 O
The production of syngas from methane produces 3 moles of hydrogen gas for every mole of carbon monoxide (and 4 moles of hydrogen per mole of carbon dioxide), while the methanol synthesis reaction consumes only 2 moles of hydrogen gas per mole of carbon monoxide (and 3 moles of hydrogen gas per mole of carbon dioxide). In both reaction pathways, one more mole of hydrogen is generated than is needed for methanol synthesis. This excess hydrogen occupies capacity in both the compressor train and the methanol reactor. As a result, the methanol production process is inefficient, resulting in unnecessary costs due to increased compressor power requirements and less than optimum methanol yields. Reactants are lost when excess hydrogen is purged from the synthesis loop and used as fuel for the reformer.
FIG. 1 is a schematic showing a conventional process for methanol production. Feed streams of natural gas 101 and steam 102 are fed into reformer 103 , resulting in the production of syngas stream 104 . Syngas stream 104 is then passed to compression chain 105 (typically comprising at least make-up compressor 105 a and recycle compressor 105 b ) to produce high-pressure gas stream 106 . High-pressure stream 106 is then passed to methanol synthesis reactor 107 to produce reaction product stream 108 , containing methanol and unreacted syngas. This stream 108 is then routed to condenser 109 , from which condensed stream 110 , containing methanol and water, drops out. Overhead stream 111 , containing unreacted syngas and enriched in hydrogen and inerts (methane and possibly nitrogen), is then split into purge stream 112 and recycle stream 113 , which is routed back to the recycle compressor 105 b , where it is combined with fresh feed.
It would be desirable to provide an improved methanol production process that is more efficient, with reduced compressor power requirements and/or improved methanol product yield.
SUMMARY OF THE INVENTION
In our earlier application, U.S. Ser. No. 13/175,399, filed Jul. 15, 2011, which has been allowed, we disclosed processes for the production of methanol from syngas which removed excess hydrogen from the syngas before it reaches the methanol synthesis loop.
We have since discovered an even more efficient process, in which excess hydrogen is removed after the methanol synthesis loop, and carbon dioxide is recycled back to the synthesis loop.
Accordingly, disclosed herein is a methanol production process including the following steps:
(a) providing a source of syngas, wherein the syngas has a first composition parameter R 1 , where R 1 >2;
(b) passing the syngas to a methanol synthesis loop to produce a condensed methanol product stream;
(c) withdrawing a purge stream from the methanol synthesis loop to limit the concentration of inerts and excess hydrogen;
(d) providing a first membrane having a first feed side and a first permeate side, where the first membrane exhibits a selectivity to hydrogen over carbon dioxide of at least about 5, and a selectivity to hydrogen over carbon monoxide of at least about 20;
(e) passing at least a portion of the purge stream across the first feed side;
(f) withdrawing from the first permeate side a hydrogen-rich first permeate stream, wherein the first permeate stream has a second composition parameter R 2 , where R 2 <R 1 ;
(g) withdrawing from the first feed side a hydrogen-depleted first residue stream;
(h) providing a second membrane having a second feed side and a second permeate side, where the second membrane is selective for carbon dioxide over hydrogen and methane;
(i) passing the first residue stream across the second feed side;
(j) withdrawing from the second feed side a carbon dioxide-depleted second residue stream;
(k) withdrawing from the second permeate side a carbon dioxide-enriched second permeate stream, wherein the second permeate stream has a third composition parameter R 3 , where R 3 <R 2 ; and
(l) passing the second permeate stream to the methanol synthesis loop.
Membranes for use in the first membrane separation step (d) preferably exhibit a selectivity to hydrogen over carbon dioxide of at least about 5 and, more preferably, at least about 10, and to hydrogen over carbon monoxide of at least about 20. Hydrogen permeance of the first membrane is typically at least 100 gpu and, preferably, at least 200 gpu.
Preferred first membrane materials include polymers, such as polyimides, polyamides, polyurethanes, polyureas, polybenzimidazoles, and polybenzoxazoles; metals, such as palladium; zeolites; and carbon, by way of example and not by way of limitation.
First membrane operating temperature is typically within the range of about 50° C. to about 150° C.; preferably, within the range of about 100° C. to about 150° C. The feed side of the first membrane is typically maintained at a pressure within the range of about 45 bar to about 100 bar, with the permeate side typically maintained at a pressure within the range of about 2 bar to about 10 bar.
Any membrane that exhibits a selectivity to carbon dioxide over hydrogen of at least about 5, and over methane of at least about 10, may be used in the second membrane separation step (h). Carbon dioxide permeance of the second membrane is typically at least 200 gpu and, preferably, at least 400 gpu.
Any membrane with suitable performance properties may be used in second membrane separation step (h). Many polymeric materials, especially elastomeric materials, are very permeable to carbon dioxide. Preferred membranes for separating carbon dioxide from other gases often have a selective layer based on a polyether.
Second membrane operating temperature is typically within the range of about 0° C. to about 80° C.; preferably, within the range of about 20° C. to about 60° C. The feed side of the second membrane is typically maintained at a pressure within the range of about 45 bar to about 100 bar, with the permeate side typically maintained at a pressure within the range of about 10 bar to about 30 bar.
By practicing the process of the invention, existing methanol plants may be made more efficient by recovering carbon dioxide from the purge gas and recycling it back to the synthesis loop. This results in additional methanol production, and is also a way of sequestering carbon dioxide, thereby preventing its release to the environment. In addition, the process of the invention generates a hydrogen-rich stream from the first membrane separation step. This hydrogen-rich stream can be used for other purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of a conventional methanol production process (not in accordance with the invention).
FIG. 2 is a schematic drawing of a basic embodiment process of the invention for methanol production that involves two membrane separation steps to treat a purge stream from the methanol production process.
DETAILED DESCRIPTION OF THE INVENTION
The terms “natural gas” and “methane” are used interchangeably herein.
Gas percentages given herein are by volume unless stated otherwise.
Pressures as given herein are in bar absolute unless stated otherwise.
For any gas stream herein, the composition may be expressed in terms of a composition parameter, R, where:
R = ( molar flow of H 2 - molar flow of CO 2 ) ( molar flow of CO + molar flow of CO 2 ) ,
Specific composition parameters are referred to herein as R 1 , R 2 , and R 3 .
A schematic drawing of a basic embodiment process of the invention for methanol production is shown in FIG. 2 . It will be appreciated by those of skill in the art that this, like FIG. 1 , is a very simple block diagram, intended to make clear the key unit operations of the process of the invention, and that an actual process train will usually include many additional steps of a standard type, such as heating, chilling, compressing, condensing, pumping, various types of separation and/or fractionation, as well as monitoring of pressures, temperatures, flows, and the like. It will also be appreciated by those of skill in the art that the details of the unit operations may differ from product to product.
Referring to the figure, feed streams of natural gas, 201 , and steam, 202 , are fed into, for example, a steam reformer, 203 , resulting in the production of syngas, 204 . Although FIG. 2 illustrates an example in which syngas is produced using a steam methane reforming process, any source of syngas can be used to provide syngas for use in the process of the invention.
The invention is particularly designed for syngas sources having an excess of hydrogen for methanol production. Expressed quantitatively, the invention is particularly directed to the manufacture of methanol from syngas having a composition parameter, R 1 , that is greater than 2; that is, R=R 1 >2.
Syngas stream 204 is then passed to a compression chain, 205 (typically comprising at least a make-up compressor, 205 a , and a recycle compressor, 205 b ), to produce a high-pressure gas stream, 206 . High-pressure stream 206 is then passed to a methanol synthesis reactor, 207 , to produce a reaction product stream, 208 , containing methanol and unreacted syngas.
Methanol synthesis reactors are known in the art and typically rely on a catalyst bed to catalyze the reaction of carbon oxides and hydrogen to produce methanol. As discussed in the Background of the Invention, the most common catalyst in use today is a mixture of copper, zinc oxide, and alumina first used by ICI in 1966. At 50-100 bar and 250° C., it can catalyze the production of methanol from carbon oxides and hydrogen with high selectivity.
Reaction product stream 208 is then routed to a condenser, 209 , from which a condensed stream, 210 , containing methanol and water, drops out. An overhead stream, 211 , containing unreacted syngas and enriched in hydrogen and inerts (methane and possibly nitrogen), is then split into a purge stream, 212 , and a recycle stream, 213 , which is routed back to the recycle compressor 205 b , where it is combined with fresh feed.
In accordance with the present invention, at least a portion of purge stream 212 is then passed as a feed stream to a first membrane unit, 214 , that includes membranes, 215 , that exhibit a selectivity to hydrogen over carbon dioxide of at least about 5; preferably, at least about 10; more preferably, at least about 15. In addition, the membranes 215 should exhibit a selectivity for hydrogen over carbon monoxide of at least about 20. Hydrogen permeance of the first membrane is typically at least 100 gpu and, preferably, at least 200 gpu.
Any membrane with suitable performance properties may be used in the first membrane separation step. Examples of such membranes include the polybenzimidazole (PBI) based membranes taught by K. O'Brien et al. in “Fabrication and Scale-Up of PBI-based Membrane System for Pre-Combustion Capture of Carbon Dioxide” (DOE NETL Project Fact Sheet 2009) and polyimide-based membranes taught by B. T. Low et al. in “Simultaneous Occurrence of Chemical Grafting, Cross-linking, and Etching on the Surface of Polyimide Membranes and Their Impact on H 2 /CO 2 Separation” ( Macromolecules , Vol. 41, No. 4, pp. 1297-1309, 2008).
Preferred first membrane materials include polymers, such as polyimides, polyamides, polyurethanes, polyureas, polybenzimidazoles, and polybenzoxazoles; metals, such as palladium; zeolites; and carbon, by way of example and not by way of limitation.
The membrane may take the form of a homogeneous film, an integral asymmetric membrane, a multilayer composite membrane, a membrane incorporating a gel or liquid layer or particulates, or any other form known in the art.
The membranes may be manufactured as flat sheets or as fibers and housed in any convenient module form, including spiral-wound modules, plate-and-frame modules, and potted hollow-fiber modules. The making of all these types of membranes and modules is well-known in the art.
Flat-sheet membranes in spiral-wound modules is the most preferred choice for the membrane/module configuration. A number of designs that enable spiral-wound modules to be used in counterflow mode, with or without sweep on the permeate side, have been devised. A representative example is described in U.S. Pat. No. 5,034,126, to Dow Chemical.
Membrane unit 214 may contain a single membrane module or bank of membrane modules or an array of modules. A single unit or stage containing one or a bank of membrane modules is adequate for many applications. If the residue stream requires further hydrogen removal, it may be passed to a second bank of membrane modules for a second processing step. If the permeate stream requires further concentration, it may be passed to a second bank of membrane modules for a second-stage treatment. Such multi-stage or multi-step processes, and variants thereof, will be familiar to those of skill in the art, who will appreciate that the membrane separation step may be configured in many possible ways, including single-stage, multistage, multistep, or more complicated arrays of two or more units, in serial or cascade arrangements.
The first membrane operating temperature is typically within the range of about 50° C. to about 150° C.; preferably, within the range of about 100° C. to about 150° C. The feed side of the first membrane is typically maintained at a pressure within the range of about 45 bar to about 100 bar, with the permeate side typically maintained at a pressure within the range of about 2 bar to about 10 bar.
Referring back to FIG. 2 , purge stream 212 is passed across the feed side of the membranes 215 . A permeate stream, 216 , is withdrawn from the permeate side. Permeate stream 216 is enriched in hydrogen as compared with purge stream 212 , and has a composition parameter R 2 , where R 2 >R 1 .
Hydrogen-rich stream 216 can be used for whatever purpose is desired. It may, for example, be used as reformer fuel gas, or used as a source of hydrogen for another process, such as ammonia production.
A hydrogen-depleted first residue stream, 217 , is withdrawn from the feed side of first membrane unit 214 . First residue stream 217 is then routed to a second membrane separation unit, 218 . Second membrane separation unit 218 includes membranes, 219 , that are selective for carbon dioxide over hydrogen, methane, and nitrogen.
In particular, the membranes in second unit 218 typically have a selectivity for carbon dioxide over hydrogen of at least about 5; over methane of at least about 10; and, over nitrogen of at least about 20. Carbon dioxide permeance of the second membrane is typically at least 200 gpu and, preferably, at least 400 gpu.
Any membrane with suitable performance properties may be used in the second membrane separation step. Many polymeric materials, especially elastomeric materials, are very permeable to carbon dioxide. Such polymeric materials are described, for example, in two publications by Lin et al., “Materials selection guidelines for membranes that remove CO 2 from gas mixtures” ( J. Mol. Struct., 739, 57-75, 2005) and “Plastization-Enhanced Hydrogen Purification Using Polymeric Membranes” ( Science, 311, 639-642, 2006).
Preferred membranes for separating carbon dioxide from other gases often have a selective layer based on a polyether. Not many membranes are known to have high carbon dioxide/hydrogen selectivity. A representative preferred material for the selective layer is Pebax®, a polyamide-polyether block copolymer material described in detail in U.S. Pat. No. 4,963,165. We have found that membranes using Pebax® as the selective polymer can maintain a selectivity of 9, 10, or greater under process conditions.
Membrane modules are as discussed above.
The second membrane operating temperature is typically within the range of about 0° C. to about 80° C.; preferably, within the range of about 20° C. to about 60° C. The feed side of the second membrane is typically maintained at a pressure within the range of about 45 bar to about 100 bar, with the permeate side typically maintained at a pressure within the range of about 10 bar to about 30 bar.
A carbon dioxide-enriched second permeate stream, 220 , is withdrawn from the permeate side of second membrane unit 218 . The carbon dioxide content in second permeate stream 220 has now been built up from about 1-3 vol % in the purge stream 212 , to about 7-30 vol % in permeate stream 220 .
Carbon dioxide-enriched second permeate stream 220 is then recycled back to the methanol synthesis loop upstream of compression chain 205 , where it joins syngas stream 204 as feed to the methanol synthesis loop. Second permeate stream 220 has a composition parameter R 3 , where R 3 <R 2 . The addition of carbon dioxide-enriched second permeate stream 220 to the feed stream to the methanol synthesis loop results in additional methanol production.
A carbon dioxide-depleted second residue stream, 221 , is withdrawn from the membrane side of second membrane separation unit 218 . This stream can then be sent for use as fuel gas or for any other desired purpose.
The invention is now further described by the following examples, which are intended to be illustrative of the invention, but are not intended to limit the scope or underlying principles in any way.
EXAMPLES
Example 1
Conventional Methanol Production Process (not in Accordance with the Invention)
The computer calculations in the following Examples were performed using a modeling program, ChemCad 5.6 (ChemStations, Inc., Houston, Tex.) containing code developed by assignee's engineering group for applications specific to assignee's processes.
The calculation for this Example was performed using the flow scheme shown in FIG. 1 and described in the Background of the Invention, above. This flow scheme does not include a membrane separation step upstream of the methanol synthesis process (not in accordance with the invention). Syngas flow was assumed to be 106 metric tons per hour (Mt/h).
The flow rates and chemical compositions of the streams in the methanol synthesis loop were calculated. The results of this calculation are shown in Table 1.
TABLE 1
Reactor
Reactor
Overhead
Recycle
Syngas
Feed Gas
Output
Condensate
Stream
Purge Gas
Gas
Parameter/Stream
104
106
108
110
111
112
113
Total Flow (Mt/h)
106
185
185
92.0
93.4
14.0
79.4
Temperature (° C.)
150
65
280
40
40
40
40
Pressure (bar)
16.5
103
95
90
88
88
88
Component (mol %)
Hydrogen
73.4
79.2
71.1
0.24
83.2
83.2
83.2
Carbon monoxide
14.9
6.6
0.80
0.01
0.93
0.93
0.93
Carbon dioxide
7.8
3.7
0.91
0.43
0.99
0.99
0.99
Methane
3.7
9.7
11.8
0.45
13.7
13.7
13.7
Nitrogen
0.20
0.54
0.65
0
0.76
0.76
0.76
Methanol
0
0.23
11.1
74.0
0.39
0.39
0.39
Water
0
0.04
3.7
24.9
0.06
0.06
0.0
In this “no membrane” example (not in accordance with the invention), approximately 96% of the carbon oxides in the syngas are converted to methanol. Most of the balance, approximately 3% of the carbon oxides in the feed syngas, is lost in the purge gas. The make-up compressor compresses 24,000 Ibmol/h, with a power consumption of 29,000 hp. The recycle compressor compresses 50,000 Ibmol/h, with a power consumption of 5,400 hp.
Example 2
Methanol Production Process in Accordance with the Invention
The calculation for this Example was performed using the flow scheme shown in FIG. 2 and described in the Detailed Description, above. This flow scheme includes two membrane separation steps downstream of the methanol synthesis loop.
The membranes, 215 , in first membrane separation unit, 214 , were assumed to have the properties shown in Table 2, at a membrane operating temperature within the range of about 50° C. and about 150° C.
TABLE 2
Gas
Permeance (gpu)*
H 2 /Gas Selectivity**
Hydrogen
300
—
Carbon monoxide
<2
>100
Carbon dioxide
20
15
Methane
<2
>100
Nitrogen
<2
>100
Water
500
0.6
*Gas permeation unit; 1 gpu = 1 × 10 −6 cm 3 (STP)/cm 2 · s · cmHg
**Estimated, not measured
The membranes, 219 , in second membrane separation unit, 218 , were selective for carbon dioxide over hydrogen and were assumed to have the properties shown in Table 3, at a membrane operating temperature within the range of about 0° C. and about 40° C.
TABLE 3
Gas
Permeance (gpu)*
CO 2 /Gas Selectivity**
Carbon dioxide
600
—
Hydrogen
60
10
Carbon monoxide
20
30
Methane
20
30
Nitrogen
30
20
Water
2000
0.3
*Gas permeation unit; 1 gpu = 1 × 10 −6 cm 3 (STP)/cm 2 · s · cmHg
**Estimated, not measured
Syngas flow for this calculation was assumed to be 106 Mt/h. First membrane 215 area was assumed to be 1,343 m 2 ; second membrane 219 area was assumed to be 1,427 m 2 .
The flow rates and chemical compositions of the streams in the methanol synthesis loop were calculated. The results of this calculation are shown in Table 4.
TABLE 4
Reactor
First
Second
Feed
Reactor
Product
Overhead
Purge
Recycle
Mem.
Mem.
Fuel
Syngas
Gas
Output
Stream
Stream
Gas
Gas
Perm.
Perm.
Gas
Parameter/Stream
204
206
208
210
211
212
213
216
220
221
Total Flow (Mt/h)
106
177
177
92
85
20
65
7.4
6.2
6.0
Temperature (° C.)
150
70
280
50
50
50
50
53
50
43
Pressure (bar)
16.5
103
95
90
88
86
86
2.1
16.5
103
Component (mol %)
Hydrogen
73.4
73.5
61.0
0.27
75.6
75.6
75.6
95.1
15.2
5.0
Carbon monoxide
14.9
8.2
1.1
0.01
1.3
1.3
1.3
0.20
4.5
5.5
Carbon dioxide
7.8
4.7
1.2
0.53
1.4
1.4
1.4
0.55
8.0
0.23
Methane
3.7
12.6
16.2
0.70
19.9
19.9
19.9
3.0
68.4
84.5
Nitrogen
0.2
0.71
0.91
0.01
1.1
1.1
1.1
0.17
3.4
4.8
Methanol
0
0.31
14.7
73.5
0.65
0.65
0.65
0.84
0.02
0
Water
0
0.05
4.9
25.0
0.11
0.11
0.11
0.14
0
0
In this “two membrane” example (in accordance with the invention), approximately 98% of the carbon oxides in the syngas are converted to methanol. Most of the balance, approximately 2% of the carbon oxides in the feed syngas, is lost in the purge gas. The make-up compressor compresses 24,800 Ibmol/h, with a power consumption of 29,800 hp. The recycle compressor compresses 50,000 Ibmol/h, with a power consumption of 5,400 hp. | Disclosed herein is a methanol production process that includes at least two membrane separation steps. Using the process of the invention, the efficiency of methanol production from syngas is increased by reducing the compression requirements of the process and/or improving the methanol product yield. As an additional advantage, the first membrane separation step generates a hydrogen-rich stream which can be sent for other uses. An additional benefit is that the process of the invention may debottleneck existing methanol plants if more syngas or carbon dioxide is available, allowing for feed of imported carbon dioxide into the synthesis loop. This is a way of sequestering carbon dioxide. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a three-wheeled motor vehicle for use as a multipurpose working machine.
2. Description of Relevant Art
Three- and four-wheeled motor vehicles are generally used as passenger vehicles and working machines.
Where four-wheeled motor vehicles or working machines are employed for cargo transportation, the operator or worker rides on the vehicle at one side or the center thereof with a space behind the operator being used for storage of the cargo. Therefore, the storage space or utility space on the four-wheeled motor vehicle for cargo transportation is reduced by the presence of the operator. In order to enlarge the storage space, the length of the vehicle frame must be increased, so that the vehicle frame is large in size as compared with the storage space.
Four-wheeled motor vehicles are also used as lawn mowers and agricultural working machines for forming furrows in the field and cultivating the soil. With such four-wheeled motor vehicles, the effective space thereon includes a space where the operator rides for driving the vehicle. Since any working attachment such as a rotor or the like cannot be installed on the operator space, it should be mounted on the vehicle frame as its front or rear end. The vehicle frame with the working attachment installed makes the motor vehicle relatively long and large, with the result that the motor vehicle cannot be well maneuvered such as when it is to be turned. Particularly, the four-wheeled agricultural working machines have proven unsatisfactory in that they cannot make turns of small radii which are often required in the field.
Where a snowplow is of a rider-controlled four-wheeled design, it is also relatively large in overall size since a space is required on the snowplow for the rider or operator to ride on and control the snowplow while a snow auger or blower is attached to the front or rear end of the snowplow frame.
Three-wheeled motor vehicles having a single front wheel and two rear wheels have been put to use as various working machines. Since the operator rides centrally on the motor vehicle, any cargo storage space or bed to be provided thereon has to be located behind the operator. If the longitudinal dimension of the motorcycle frame is to be fixed, then the cargo storage space will be relatively small. If the cargo storage space is to be enlarged, then the cargo storage bed will be extended rearwardly, making the overall size large. In case the cargo storage bed is located in front of the operator's seat, a limitation is imposed on the size of the cargo storage bed by desired drivability and maneuverability of the motor vehicle.
Where such a three-wheeled motor vehicle is used as an agricultural working machine, the front wheel positioned centrally between the rear wheels, as seen longitudinally of the motor vehicle, tends to ride on and break a ridge formed on the field between the rear wheels. Any working attachment such as a rotor has to be connected to the rear end of the vehicle frame, and hence increases the longitudinal dimension and the overall size of the motor vehicle.
The present invention has been made in an effort to eliminate the drawbacks with the conventional three- and four-wheeled motor vehicles used as various working machines.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a three-wheeled motor vehicle which has a large utility space substantially coextensive with the transverse and longitudinal dimensions of the motor vehicle for storing cargo or supporting a working unit or attachment, is small in size even with the working attachment installed, can make small turns, can be maneuvered well on rough terrain, and is simple in structure.
To achieve the above object, there is provided a motor vehicle comprising a steering handle, a rider's seat disposed behind the steering handle, a front wheel disposed in front of the steering handle and steerable by the steering handle, a rear wheel disposed behind the rider's seat and substantially aligned with the front wheel along an axis, an engine for driving at least the rear wheel, a side runner disposed between the front and rear wheels as seen in side elevation and spaced transversely from the axis of the front and rear wheels, a steering mechanism for steering the side runner in coaction with the front wheel, and a structural body supporting the front and rear wheels and the side runner and defining a space located between the axis and the side runner and opening in the longitudinal direction of the motor vehicle.
A rider rides on the motor vehicle between the front and rear wheels, and the space between the axis thereof and the side runner opens in the longitudinal direction. Therefore, a cargo bed or a working unit can be disposed between the axis and the side runner and extend fully in the longitudinal dimension of the motor vehicle. Therefore, the motor vehicle can provide a large utility space while remaining small in size. Since the side runner is steerable in coaction with the front wheel, the motor vehicle can make small turns and hence can be maneuvered well on rough terrain. As a consequence, a small-size, rider-controlled cargo transportation vehicle or working machine can be provided which has a required large-size utility space thereon.
The above and further objects, details and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a three-wheeled motor vehicle according to a first embodiment of the present invention, the motor vehicle being used as a cargo transportation vehicle;
FIG. 2 is a perspective view of the three-wheeled motor vehicle of FIG. 1, with a cover, a seat, and a cargo bed omitted from illustration;
FIG. 3 is a plan view of a drive mechanism and a steering mechanism of the motor vehicle of FIG. 1;
FIG. 4 is a schematic view showing the relationship between the front, rear and side runner wheels;
FIG. 5 is a perspective view of a modification of the cargo transportation vehicle shown in FIG. 1;
FIG. 6 is a perspective view of a three-wheeled motor vehicle according to a second embodiment of the present invention, the motor vehicle being used as a rider-controlled lawn mower;
FIG. 7 is a perspective view of the three-wheeled motor vehicle of FIG. 6, with a cover, a grass bag, and a duct omitted from illustration;
FIG. 8 is a plan view similar to FIG. 3, showing a drive mechanism of the motor vehicle of FIG. 6;
FIG. 9 is a plan view illustrating the relationship between the three wheels and a working machine comprising a cutter housing, the grass bag, and the duct in the embodiment of FIG. 6;
FIG. 10 is a plan view similar to FIG. 9, but showing a conventional four-wheeled rider-controlled lawn mower;
FIG. 11 is a perspective view of a three-wheeled motor vehicle according to a third embodiment of the present invention, the motor vehicle being used as a rider-controlled agricultural working machine;
FIG. 12 is a plan view similar to FIG. 3, primarily showing a drive mechanism of the motor vehicle of FIG. 11;
FIG. 13 is a perspective view of a three-wheeled motor vehicle according to a fourth embodiment of the present invention, the motor vehicle being used as a rider-controlled snowplow;
FIG. 14 is is a plan view similar to FIG. 3, primarily showing a drive mechanism of the motor vehicle of FIG. 13;
FIG. 15 is a perspective view of a three-wheeled motor vehicle according to a fourth embodiment of the present invention, the motor vehicle being used as a snowmobile;
FIG. 16 is a perspective view of a three-wheeled motor vehicle according to a fifth embodiment of the present invention, the motor vehicle being used as a cargo transportation vehicle with an engine differently positioned; and
FIG. 17 is a plan view similar to FIG. 3, primarily illustrating a drive mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIGS. 1 and 2, a three-wheeled motor vehicle according to a first embodiment of the present invention is used primarily as a cargo transportation vehicle and may also be used as an agricultural working machine with attachments. The motor vehicle includes a frame 1 having two upper members 1b, 1b extending rearwardly from the upper end of a head tube 1a. Submembers 1c, 1c extend downwardly in a V shape from the central portion of each of the upper members 1b, 1b. A rear wheel 2 is supported on a rear fork 1d pivotally coupled to the submembers 1c, 1c. A cushioning unit 3 is disposed on each side of the frame 1 and connected between the rear fork 1d and the upper member 1b.
A transversely extending lower cross member 1e has one end coupled to the lower end of the head tube 1a. A lower side member if extends rearwardly from the other end of the lower cross member 1e toward the rear wheel 2. The lower side member if has an output shaft supporting portion 1g bent transversely inwardly. A submember 1h extends as an oblique beam between the upper end of the head tube 1a and the other end of the lower cross member 1e. A fuel tank 4 is supported on the upper members 1b, 1b above the rear wheel 2, and a rider's seat 5 is disposed in front of the fuel tank 5 as shown in FIG. 1.
A front wheel 6 is disposed in front of the head tube 1a and substantially aligned with the rear wheel 2 in the longitudinal direction of the frame 1. The front wheel 6 is supported at one side thereof on a leading arm assembly 7 comprising upper and lower leading arms 7a, 7b extending forwardly from an intermediate portion of the lower cross member 1e. The leading arms 7a, 7b have ends 7d, 7d pivotally coupled by a bracket 7e to the lower cross member 1e so as to be kept parallel to each other. A cushioning unit 8 is connected between an intermediate portion of the upper arm 7a and an upper portion of the submember 1h. The leading arms 7a, 7b have outwardly bent front ends 7c on which the front wheel 6 is supported.
A side wheel 9 is supported on the end of the lower cross member 1e remote from the head tube 1a. The side wheel 9 being idly rotatable. Between the side wheel 9 and the front and rear wheels 6, 2, there is defined a longitudinally open space flanked on one side thereof with a region where a rider rides between the front and rear wheels 6, 2 astride of the rider's seat 5.
While the front and rear wheels 6, 2 are shown in FIGS. 1 through 3 as being substantially aligned longitudinally of the frame 1, the front wheel 6 may be displaced or offset inwardly from the rear wheel 2 by a desired distance a as shown in FIG. 4. The side wheel 9 may also be displaced or offset rearwardly from the front wheel 6 by a desired distance b.
An engine 10 is supported on the frame 1 behind the head tube 1a and in front of the upper members 1b, 1b. An air cleaner 11 is disposed over the engine 10 and has an upper half portion projecting above the front portions of the members 1b, 1b. The engine 10 has a cylinder unit 10a and a crankcase 10b (FIG. 3) therebelow. A transmission case 12 is positioned inwardly of the crankcase 10b and faces through the space toward the side wheel 9. An exhaust pipe 13 connected to the front portion of the engine 10 is bent rearwardly to lie on an outer side of the engine 10 and connected to a muffler 14 placed between the rear wheel 2 and the engine 10. In the foregoing frame arrangement, the engine 10 is positioned just behind the head tube 1a and between the front and rear wheels 6, 2, while the transmission case 12 is disposed sideways of the engine 10. Therefore, various accessories to the engine 10 can easily be positioned, and the muffler 14 is not required to be located on one side of the engine 10. Since the transmission case 12 is positioned on one side of the engine 10, the height of the engine 10 can be lowered and hence the frame 1 can have an increased height from the ground. As a consequence, the three-wheeled motor vehicle can also be used advantageously as an agricultural working machine, a lawn mower, or the like.
As shown in FIG. 3, the front and rear wheels 6, 2 can be driven by the engine 10 through a shaft drive mechanism described below. A first output shaft 12b extending rearwardly from a rear portion 12a of the transmission case 12 is coupled to a propeller shaft 15 by a universal joint 15a. The propeller shaft 15 extends rearwardly and is coupled by a universal joint 15b to the input shaft 16a of a gear box 16 disposed inwardly of the rearwheel 2 and connected thereto.
A second output shaft 12d extends forwardly from a front, transversely intermediate portion 12c of the transmission case 12 and is coupled to a propeller shaft 17 by a universal joint 17a.The propeller shaft 17 extends obliquely forwardly toward the front wheel 6 and is connected by a universal joint 17b to a gear box 18 located sideways of the front wheel 6. The gear box 18 can be angularly moved by a knuckle arm 27 as the front wheel 6 is steered, as described later.
Another gear box 19 is disposed on one side 12e of the transmission case 12 which is remote from the engine 10. First and second output shafts 20, 21 project forwardly and rearwardly from the gear box 19, respectively. The first or front output shaft 20 has a front output end 20b projecting through a bearing 20a on the lower cross member 1e near its outer end. The second or rear output shaft 21 extends rearwardly over a longer distance and has a rear output end 21b projecting through a bearing 21a on the output shaft supporting portion 1g.
The front wheel 6 and the side wheel 9 can be steered by a steering mechanism as follows: A steering shaft 22a is rotatably disposed in the head tube 1a and has an upper end projecting out of the head tube 1a and joined to a handlebar 22. To the lower end of the steering shaft 22a, there is connected a pitman arm 23 coupled to a front wheel relay rod 24 by a universal joint 23a. A V-shaped link 25 is pivotally mounted by a pivot shaft 25b on the lower cross member 1e and has one end 25a coupled to the relay rod 24 by a universal joint 24a. The other end of the link 25 is coupled by a universal joint 26a to a tie rod 26 connected by a universal joint 26b to the knuckle arm 27 which supports the front wheel 6 and the gear box 18.
The side wheel 9 is vertically swingably supported on the side member 1f by a swing arm 28 having an end 28a pivotally mounted on the front outer side of the side member 1f. The swing arm 28 is of an inverted L shape having a bent outer end on which there is pivotally supported a knuckle arm 29 supporting the hub of the side wheel 9. The knuckle arm 29 is connected by a universal joint 30a to one end of a side wheel tie rod 30. The other end of the tie rod 30 is coupled to the pitman arm 23 by the universal joint 23a. A cushioning unit 31 is interposed between the swing arm 28 and the side member 1f. Alternatively, the side wheel 9 may be supported on a rigid arm with no cushioning means.
As illustrated in FIGS. 1 and 2, a cover 32 is attached to the frame 1 in surrounding relation to the head tube 1a and the upper members 1b, 1b and supports a headlight unit 33 on its front portion. Another cover 34 is disposed around the handlebar 22. A cargo bed 35 is disposed in the space between the front and rear wheels 6, 2 and the side wheel 9. The cargo bed 35 has a floor 35a supported on the lower cross member 1e and the side member 1f, and also has laterally spaced side bars 35b, 35b and a front cover 35c. The cargo bed 35 is disposed between the front and rear wheels 6, 2 and the side wheel 9. The rider's seat 5 is positioned between the front and rear wheels 6, 2 for the rider to ride astride thereof. Since the rider's seat 5 is located on one side of the cargo bed 35, the cargo bed 35 can extend substantially the full longitudinal dimension of the motor vehicle and also substantially the full transverse distance between the front and rear wheels 6, 2 and the side wheel 9. Therefore, the cargo bed 35 can be of a maximum length and width without being limited by the rider, and is relatively large as compared with the outer dimensions of the motor vehicle.
The motor vehicle has a speed change lever 36 operatively coupled to the transmission case 12 for effecting switching between a constant-speed mode of operation in which a governor is used such as when the motor vehicle is used for agricultural work and a normal variable-speed mode of operation in which the motor vehicle is driven to travel or used as a cargo vehicle.
As illustrated in FIG. 3, engine power is transmitted from the transmission case 12 through the propeller shafts 17, 15 to the gear cases 18, 16 for thereby driving the front and rear wheels 6, 2 to enable the motor vehicle to run at various speeds, move, and run at a constant speed. Since both the front and rear wheels 6, 2 are driven, the motor vehicle can run reliably and powerfully for cargo transportation or agricultural work. Attachments can be connected to the output shafts 20, 21 driven by the engine 10 for effecting desired types of work. While the motor vehicle is running, it can be steered by the handlebar 22. The turning movement of the handlebar 22 is transmitted through the steering shaft 22a to the pitman arm 23 and then through the relay rod 24, the link 25, and the tie rod 26 to the knuckle arm 27 for steering the front wheel 6. The pitman arm 23 is also coupled through the tie rod 30 to the knuckle arm 29 of the side wheel 9. By selecting a suitable lever ratio between the relay rod 24 with the tie rod 26 and the tie rod 30, the side wheel 9 can be steered in the same direction through the same angle by the handlebar 22. The steering movement of the front and side wheels 6, 9 in the same direction through the same angle allows the motor vehicle to turn stably with a relatively small radius, making the motor vehicle highly suitable for use as an agricultural working machine.
While an ordinary tire may be mounted on the front wheel 6, it is preferable to mount a low-pressure tire known as a balloon tire on the front wheel 6 in view of operation on rough terrain such as agricultural land, wasteland, sandy ground, and snow-covered land. Where such balloon tires are used, the cushioning units 3, 8, 31 may be dispensed with since the balloon tires themselves have a cushioning ability, and the rear fork 1d, the leading arm 7, and the swing arm 28 may be fixed for a simpler frame mechanism.
FIG. 5 shows a modification of the above first embodiment of the present invention. According to this modification, a front cover 135c of a cargo bed 135 is integrally coupled to a front portion of a frame cover 132 having a fender 132a on its front end. The other structural details are the same as those of the motor vehicle of the first embodiment, and will not be described, with some of them being denoted by the same reference numerals as those shown in FIGS. 1 through 4.
FIGS. 6 through 10 illustrate a motor vehicle as a rider-controlled lawn mower according to a second embodiment of the present invention.
The front and rear wheel drive mechanism, the engine, the transmission case, the steering mechanism, and the frame of the motor vehicle of the second embodiment are identical to or substantially the same as those of the first embodiment, and will not be described in detail. Like components are designated by the same reference characters as in FIGS. 1 through 3.
As shown in FIGS. 7 and 8, a cutter housing 232 is disposed below the frame 1 and supported by the frame 1. The cutter housing 232 is of a substantially elliptical shape having straight intermediate sides. The cutter housing 232 has an end 232a positioned in front of the side wheel 9 and the opposite end 232b located between the front and rear wheels 6, 2. Thus, the cutter housing 232 lies obliquely, as seen in plan, with respect to the longitudinal axis of the motor vehicle. The cutter housing 232 includes a top wall 232c, a peripheral wall 232d, and an open bottom. Two cutter blades 233, 234 rotatable in a horizontal plane are accommodated in the cutter housing 232 respectively at opposite portions thereof, the cutter blades 233, 234 being rotatable out of phase with each other so that they will not interfere with each other during rotation. The cutter blades 233, 234 have respective shafts 233a, 234a with ends projecting upwardly through the top wall 232c and connected to pulleys 235, 236, respectively, which are vertically displaced one from the other by a distance equal to the width of a belt (described hereinbelow). The shaft 233a has its upper end supported by a bracket 1i mounted on the lower cross member 1e, and the shaft 234a has its upper end similarly supported, although not shown.
A gear box 237 is mounted on an intermediate portion of the lower cross member 1e. The output shaft 20 extends through the gear box 237 and has a worm gear 238 disposed in the gear box 237 and held in mesh with a worm gear 240 mounted on a shaft 239 extending vertically in perpendicular relation to the output shaft 20. The shaft 239 extends downwardly from the gear box 239 through the lower cross member 1e and is connected at its lower end to a two-groove pulley 241 having upper and lower grooves of the same diameter. Belts 242, 243 are trained around the pulleys 235, 236, respectively, and the grooves of the pulley 241. Therefore, when the output shaft 20 is driven to rotate, the pulley 241 is rotated to cause the belts 242, 243 and the pulley 235, 236 to rotate the cutter blades 233, 234 for cutting grass. A guide roller 244 is attached to the cutter housing 232 and extends forwardly from one side of the cutter housing 232 for contact with the ground.
A grass bag 245 is disposed behind the cutter housing 232 for accommodating grass clippings. The grass bag 245 is located sideways of the rear wheel 2 behind the side wheel 9. The grass bag 245 is rectangular in shape as seen in plan, and has one side 245a positioned just inwardly of the rear wheel 2 and the opposite side 245b positioned directly behind the side wheel 9 and lying flush with or slightly inwardly of the outer side of the side wheel 9. The grass bag 245 has a rear side 245c lying substantially flush with the rear end of the rear wheel 2. The grass bag 245 comprises upper and lower members 246, 247. The lower member 247 has a front side 247a (FIG. 6) slanted downwardly and rearwardly so as not to interfere with the side wheel 9. The grass bag 245 is supported on the rear portion of the frame 1. To the front side of an intermediate portion 246a of the upper member 246, there is connected the rear end of a duct 248 extending obliquely downwardly in the forward direction and having its front end coupled to an intermediate portion of the cutter housing 232.
The frame 1 is surrounded by a cover 249 including a front fender 249a extending in covering relation to the front wheel 6. The cover 249 also has a front cover 249b covering the cutter housing 232 and a side cover 249c extending rearwardly from the outer end of the front cover 249b and between the side wheel 9 and the duct 248. The cover 249 supports a headlight unit 250 in front of the handlebar 22.
The motor vehicle runs when the front and rear wheels 6, 2 are driven to rotate, while the side wheel 9 rolls on the ground. Also during this time, the cutter blades 233, 234 are rotated to cut grass, and the grass clippings are delivered through the duct 248 into the grass bag 245 in which the grass clippings are stored.
Although the front and rear wheels 6, 2 are shown as being driven at the same time, only the rear wheel 2 may be driven. Similarly, the cutter housing may accommodate only one cutter blade rather the illustrated two cutter blades.
As can be understood from FIG. 9, the operator rides on the motor vehicle between the front and rear wheels 6, 2, and the cutter housing 232, while the cutter housing 232 is positioned in the space between the front and rear wheels 6, 2 and the side wheel 9. Since the operator is positioned sideways of this space, that portion of the space behind the cutter housing 232 is open and available for the grass bag 245 to be located herein. The result of this arrangement is that the duct 248 interconnecting the cutter housing 232 and the grass bag 245 is disposed substantially centrally of the motor vehicle in the transverse direction thereof. Therefore, the grass bag 245 is contained within the dimensions of the motor vehicle without projecting rearwardly or laterally thereof. A conventional four-wheeled, rider-controlled lawn mower is comparatively shown in FIG. 10. According to such known configurations, a grass bag 249 projects rearwardly from the motor vehicle 277 and a duct 280 projects laterally of the motor vehicle 277. According to the present invention, the cutter housing, the grass bag, and the duct, which are of the same capacities or sizes as those of the conventional designs, can be contained in the longitudinal and transverse dimensions of the motor vehicle, so that the outer shape of the motor vehicle is compact and small in size while maintaining desired functions.
FIGS. 11 and 12 show a three-wheeled motor vehicle used as an agricultural working machine according to a third embodiment of the present invention.
The front and rear wheel drive mechanism, the engine, the transmission case, the steering mechanism, and the frame of the motor vehicle of the third embodiment are also identical to or substantially the same as those of the first embodiment, and will not be described in detail. Like components are designated by the same reference characters as in FIGS. 1 through 3.
According to the third embodiment, the front and rear wheels 6, 2 and the side wheel 9 have balloon tires capable of gripping the ground and running reliably thereon when running and moving over agricultural land, and are supported by suspensions with no cushioning units. The rear fork 1d, the leading arm assembly 7, and the swing arm 28 are fixed to the frame 1. To provide for maneuvering on agricultural land, a screen 332a is disposed on a lower portion of a cover 332 for preventing mud from being attached to the engine 10, and the cover 332 has a raised front fender 332b.
A cultivating unit 340 is disposed in the space between the front and rear wheels 6, 2 and the side wheel 9 for forming furrows in the field or breaking up the soil surface. The cultivating unit 340 has a rotor 341 composed of a plurality of blades 344 spaced axially and mounted on a drive shaft 343 supported horizontally in a case 342 opening downwardly, forwardly, and rearwardly. The blades 344 are arranged on one side of the rear wheel 2 toward the outer side of the side wheel 9. Therefore, the width of a strip of ground which can be cultivated at one time by the cultivating unit 340 is increased. Speed reducer cases 345, 345 are mounted on the opposite sides of the case 342 and support on their front ends a transmission shaft 346 extending between the speed reducer cases 345, 345. The transmission shaft 346 is operatively coupled by a gear box 347 and a universal joint 21c to the rear output shaft 21. The gear box 347 houses bevel gears (not shown) for driving the transmission shaft 346. Opposite ends of the transmission shaft 346 are disposed in the speed reducer cases 345, 345, respectively, and have sprockets 348, 348 which are operatively coupled by chains 350, 350 to sprockets 349, 349 mounted on the drive shaft 343. Therefore, the rotor 341 can be driven to rotate by the output shaft 21. The mechanism for transmitting engine power to the rotor 341 is not limited to the illustrated structure, but may be of other designs.
The cultivating unit 340 has a front portion 340a fixed to the frame 1 and a rear portion 340b accommodating the rotor 341 and vertically pivtally supported by a hinge 340c. When working on the land, the rear portion 340b is lowered to bring the rotor 341 into contact with the ground. When the working machine is to be moved from one placed to another, the rear portion 340b is raised to lift the rotor 341 out of contact with the ground.
By installing the agricultural attachment or cultivating unit 340, the working machine can cultivate the land. During cultivating operation, the operator rides on the rider's seat 5 out of interference with operation of the cultivating unit 340, which is located between the rider's seat 5 and the outer side of side wheel 9. Since the front and rear wheels 6, 2 travel in substantially the same path on the ground and the side wheel 9 is spaced laterally from the front and rear wheels 6, 2, the rotor 341 operates between the front and rear wheels 6, 2 and the side wheel 9 to cultivate the land therebetween and behind the side wheel 9. In this manner the wheels 6, 2, 9 do not interfere with the cultivated soil. As the rider rides on one side of the cultivating unit soil. As the rider rides on one side of the cultivating unit 340, rather than in front thereof, the working machine need only be of a longitudinal dimension required to accommodate the cultivating unit 340. Therefore, the rider-controlled working machine is of a compact outer shape while ensuring practically sufficient functions thereof. The working machine can make small turns and hence can be easily maneuvered in various directions because the front and side wheels 6, 9 are steerable. The front and rear wheels 6, 2 which are drivable by the engine 10 enable the working machine to run reliably and powerfully on rough terrain. Therefore, the small-sized rider-controlled agricultural working machine of the present invention provides good performance and good operating functions. While the illustrated agricultural working machine serves as a cultivator, it may also be used as a seeding machine, a fertilizer sprinkling machine, or an antiseptic spraying machine.
FIGS. 13 and 14 illustrate a three-wheeled motor vehicle employed as a rider-controlled snowplow according to a fourth embodiment of the present invention. The front and rear wheel drive mechanism, the engine, the transmission case, the steering mechanism, and the frame of the motor vehicle of the fourth embodiment are also identical to or substantially the same as those of the first embodiment, and will not be described in detail. Like components are designated by the same reference characters as in FIGS. 1 through 3.
In the fourth embodiment, the front and rear wheels 6, 2 and the side wheel 9 have balloon tires for runing over snow-covered land, and are supported by suspensions with no cushioning units. The rear fork 1d, the leading arm assembly 7, and the swing arm 28 are fixed to the frame 1.
A snowplow unit 460 is positioned in the space between the front and rear wheels 6, 2 and the side wheel 9. As shown in FIG. 14, the snowplow unit 460 includes an auger 461 disposed laterally inwardly of the front wheel 6 in the space between the front wheel 6 and the outer side of the side wheel 9. The auger 461 is supported on a shaft 462 and extending transversely of the snowplow. The auger 461 has an outer end positioned in front of the side wheel 9. The shaft 462 is rotatably supported on opposite flanges 463a, 463b of a cover 463, which cover has open front and lower portions. The shaft 462 is operatively coupled by a gear box 464 on its intermediate portion through a drive shaft 465 extending longitudinally and perpendicularly to the shaft 462. The drive shaft 465 is coupled to the output shaft 20 by a universal joint 466. Thus, when the engine 10 is operated, the shaft 465 is driven to cause the gear box 464 to rotate the auger shaft 462. The auger 462 is then driven to gather snow rearwardly into a central position while the snowplow is in motion.
As shown in FIG. 13, the cover 463 has a duct 467 on its central back portion, the duct 467 extending upwardly and supporting a snow-discharging guide 468 angularly adjustably on its upper end. The duct 467 includes an intermediate and upper portion 467a angularly movable with respect to a lower portion 467b. A snow-discharging blower 469 is mounted on the drive shaft 465 behind a rear wall 463c of the cover 463. The blower 469 is positioned in the lower portion 467b of the duct 467 which is held in communication with the rear wall 463c through an opening 463d. When the auger 461 is rotated, the blower 469 is also rotated to discharge snow gathered by the auger 461 through the duct 467.
Two laterally spaced brackets 463e, 463e are mounted on the upper portion of the rear wall 463c of the cover 463. Two rods 471, 471 have front ends pivotally mounted respectively on the brackets 463e, 463e by a shaft 472 and rear ends 471a, 471a pivotally connected to the rear end of a base 470 of the snowplow unit 460 mounted on the frame 1. Laterally spaced lift arms 473 on the front portion of the base 470 have front ends pivotally coupled by pivot shafts 473a to bracketks 463f mounted on the rear wall 463c of the cover 463, and are positioned outwardly of the brackets 463e, respectively. When the lift arms 473 are driven to move angularly, the unit composed of the auger 461, the cover 463, the blower 469, the duct 467, and the shaft 465 can be lifted so that they will not interfere with movement of the snowplow from one place to another.
The rider-controlled snowplow, which is of a compact size and capable of functioning well, can be easily assembled simply by changing the plow attachment on its front end. A frame cover 432 includes a high front fender 432a and a windshield 432c positioned in front of the handlebar 22.
FIG. 15 shows a three-wheeled motor vehicle constructed as a snowmobile according to a fifth embodiment of the present invention. The front and rear wheel drive mechanism, the engine, the transmission case, the steering mechanism, and the frame of the motor vehicle of the fifth embodiment are also identical to or substantially the same as those of the first embodiment, and will not be described in detail. Like components are designated by the same reference characters as in FIGS. 1 through 3.
The illustrated snowmobile has a side ski 509 instead of the side wheel. The ski is supported by a knuckle 529 on a swing arm 528 and operatively connected to a tie rod 530, so that the side ski 509 and the front wheel 6 can be steered at the same time. A cushioning unit 531 is connected between the side ski 509 and an arm 502 projecting from the frame. The side ski 509 is vertically angularly movable about a pivot shaft 509a while being dampened by a damper 509b.
A passenger's seat 590 is mounted centrally on a cargo bed 535 with a cargo storage space 535a left behind the seat 590. A front cover 592 is disposed on the front end of the cargo bed 535 and includes a windshield 591. A frame cover 532 also has a windshield 532c.
The snowmobile thus constructed allows cargo and a passenger to be carried thereon.
FIGS. 16 and 17 show a modification in which the engine is differently installed. In this modification, only the engine is in a different position. The front and rear wheel drive mechanism, the engine, the transmission case, the steering mechanism, and the frame of the motor vehicle of this modified embodiment are also identical to or substantially the same as those of the first embodiment, and will not be described in detail. Like components are designated by the same reference characters as in FIGS. 1 through 3.
An engine 610 is installed in the space between the front and rear wheels 6, 2 and the side wheel 9 and located inwardly of the side wheel 9. The engine 610 has a cylinder portion 610a and a crankcase 610b therebelow, there being a transmission case 612 located inwardly of the crankcase 610b. A propeller shaft 615 extends rearwardly from the transmission case 612 for transmitting engine power to the gear box 16 operatively coupled to the rear wheel 2. Another propeller shaft 17 projects forwardly from the transmission case 612 for transmitting engine power to the gear box 18 operatively coupled to the front wheel 6. The engine 610 has an exhaust pipe 613 extending rearwardly and connected to a muffler 614.
An engine hood 691 is disposed inwardly of a frame cover 632, and a cargo bed 635 extends rearwardly from the engine hood 691. The engine hood 691 has an air inlet 692 comprising a screen mesh and a headlight unit 693 positioned laterally of the air inlet 692. The illustrated three-wheeled motor vehicle serves as a cargo transportation vehicle.
The engine may therefore be located between the front and rear wheels 6, 2 and the side wheel 9. While the illustrated motor vehicle is a cargo transportation vehicle, it may be an agricultural working machine, a snowplow, a lawn mower or a snowmobile.
Although there have been described what are at present considered to be the preferred embodiments of the present invention, it will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all aspects as illustrative, and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description. | A motor vehicle having a steering handle, a rider's seat disposed behind the steering handle, a front wheel disposed in front of the steering handle and steerable by the steering handle, a rear wheel disposed behind the rider's seat, an engine for driving at least the rear wheels, and a side runner. The front and rear wheel are held in substantial alignment with each other along an axis. The side runner is disposed between the front and rear wheels as seen in side elevation and spaced transversely from the axis. The motor vehicle also has a steering mechanism for steering the side runner in coaction with the front wheel, and a structural body supporting the front and rear wheels and the side runner and defining a space located between the axis and the side runner and opening in the longitudinal direction of the motor vehicle. | 8 |
BACKGROUND OF THE INVENTION
[0001] ‘MC BRIAN’ is a product of a breeding-program which had the objective of creating new chrysanthemum cultivars with a anemone type flower, a 7 week response and a medium plant height. The new plant of the present invention comprises a new and distinct cultivar of Chrysanthemum plant. ‘MC BRIAN’ is a seedling from a cross in a breeding program maintained under the control of inventor. The female parent is # 94.1444, the male parent is 93.1022 -both unpatented-, and unamed seedlings not available to inventor for description. The new and distinct cultivar was discovered and selected as a flowering plant within the progeny of the stated cross by Rob Noodelijk in a controlled environment (greenhouse) in Rijsenhout Holland in April 1997. The first act of asexual reproduction of ‘MC BRIAN’ was accomplished when vegetative cuttings were taken from the initial selection in June 1997 in a controlled environment in Rijsenhout Holland.
SUMMARY OF THE INVENTION
[0002] The present invention is a new and distinct variety of chrysanthemum bearing small sized blooms with dark purple ray-florets and grey center.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The present invention of a new and distinct variety of chrysanthemum is shown in the accompanying drawings, the color being as nearly true as possible with color photographs of this type. FIG. 1 shows a plant of the cultivar in fall bloom. FIG. 2 shows the various stages of bloom of the new cultivar. FIG. 3 shows the foliage of the new cultivar
DESCRIPTION OF THE INVENTION
[0004] This new variety of chrysanthemum is of the botanical classification chrysanthemum morifolium. The observations and measurements were gathered from plants grown in a greenhouse in Rijsenhout Holland in a photo-periodic controlled crop under conditions generally used in commercial practice. The greenhouse temperatures during this crop were at day-time between 18° C. and 25° C. and at night 20° C. The photo-periodic response time in this crop was 52 days after an average of eight long days. After this long day period to flowering growth retardants were applied 6 times in an average dose of 1.5 gram/liter water. The plants were observed (directly) during the flowering of this crop. No tests were done on disease or insect resistance or susceptibility. No tests were done on cold or drought tolerance. This new variety produces small sized blooms with dark purple ray-florets and grey center blooming on the plant for 5 weeks. This new variety of chrysanthemum has been found to retain its distinctive characteristics throughout successive propagations however the phenotype may vary significantly with variations in environment such as light intensity and temperature. To show the phenotype as described ‘MC BRIAN’ can be planted without assimilation lightning (high pressure sodium lamps) between week 50 and week 40 of the next year under greenhouse conditions in Holland. With assimilation lightning (minimum level 2500 lux) it can be planted year round under greenhouse conditions in Holland.
[0005] From the cultivars known to inventor the most similar existing cultivar in comparison to ‘MC BRIAN’ is ‘Visalia’ (USPP # 11760) . When ‘Visalia’ and ‘MC BRIAN’ are being compared the following differences are noticed: The difference of ‘Visalia’ and ‘MC BRIAN’ are (1) Flower color (2) Flower size (3) Growth habit and (4) Foliage size. The following is a description of the plant and characteristics that distinguish ‘MC BRIAN’ as a new and distinct variety. The color designations are taken from the plant itself. Accordingly, any discrepancies between the color designations and the colors depicted in the photographs are due to photographic tolerances. The color chart used in this description is: The Royal Horticultural Society color chart, edition 1995.
CULTIVAR ‘MC BRIAN’
[0006] Bud
[0007] [0007] Size.— Medium; cross-section 0.9 cm, height 1.0 cm.
[0008] [0008] Outside Color.— Red-purple 71 B.
[0009] [0009] Involucral bracts.— 2 rows, length 7 mm, width 3 mm.
[0010] [0010] Involucral bractsamong disc-florets.— Not present.
[0011] [0011] Involucral bracts color.— Green 143 C.
[0012] Bloom
[0013] [0013] Type.— Anemone.
[0014] [0014] Height.— Flat.
[0015] [0015] Size.— Small.
[0016] [0016] Fully Expanded.— 4.0-4.5 cm.
[0017] [0017] Number of blooms per branch.— Approx. 3-4 blooms per branch.
[0018] [0018] Performance on the plant.— 5 weeks.
[0019] [0019] Seeds.— Produced in small quantities,oval shaped, grey-brown 199A, 1.5 mm in length.
[0020] [0020] Fragrance.— Typical chrysanthermum.
[0021] Color
[0022] [0022] Center of the flower(disc-florets).— Immature greyed-green 195 C Mature int he center greyed-green 195 C, the outer part red-puple 71 A.
[0023] [0023] Color of upper surface of the ray.— Red-purple 71 A florets.
[0024] [0024] Color of the lower surface of the.— Red-puple 70 B ray-florets.
[0025] [0025] Tonality from Distance.— A pot mum with dark purple flowers and a grey center.
[0026] [0026] Color of the surface of the ray.— None floret safter aging of the plant.
[0027] Ray florets
[0028] [0028] Texture.— Upper and under side smooth.
[0029] [0029] Number.— 52-56.
[0030] [0030] Cross-section.— Concave.
[0031] [0031] Longitudinal axis of majority.— Straight to incurving.
[0032] [0032] Length of corolia tube.— Short.
[0033] [0033] Ray-floret length.— 1.6-1.8 cm.
[0034] [0034] Ray-floret width.— 0.5-0.7 cm.
[0035] [0035] Ratio length/width.— Low.
[0036] [0036] Shape of tip.— Round, somewhat dentate.
[0037] Disc florets
[0038] [0038] Disc diameter.— 2.2-2.4 cm.
[0039] [0039] Distribution of disc florets.— Numerous, clearly visible at all stages of flowing
[0040] [0040] Shape.— Petaloid.
[0041] [0041] Color.— Red-puple 71 A, greyed-green 195 B at the tip
[0042] [0042] Receptacle shape.— Domed raised.
[0043] Reproductive Orgens
[0044] [0044] Stamen (present in disc florests only).— No stamen.
[0045] [0045] Pollen.— No pollen Pollen color
[0046] [0046] Styles (present in both ray and disc.— Thin florets).
[0047] [0047] Styles color.— Yellow.
[0048] [0048] Styles Length.— 3 mm.
[0049] [0049] Stigmas.— Yellow.
[0050] [0050] Stigma Width.— 1 mm.
[0051] [0051] Ovaries.— Enclosed in calyx.
[0052] Plant
[0053] [0053] Form.— A pot mum meant for indoor use.
[0054] [0054] Growth habit.— Upright.
[0055] [0055] Growth rate.— Moderate to rapid.
[0056] [0056] Height.— 26.0-29.0 cm.
[0057] [0057] Width.— 24.0 cm.
[0058] [0058] Stem Color.— Green 143 C.
[0059] [0059] Stem Strength.— Very strong.
[0060] [0060] Stem Brittleness.— Absent.
[0061] [0061] Stem Anthocyanin Coloration.— Absent.
[0062] [0062] Length of lateral branch.— From top to bottom 14.0-15.0 cm.
[0063] [0063] Lateral branch color.— Green 143 C.
[0064] [0064] Lateral branch, attachment.— Very strong.
[0065] [0065] Branching (average number of.— Good with 5 braks after pinching lateral branches).
[0066] [0066] Peduncle length.— 4.0-5.0 cm.
[0067] [0067] Peduncle color.— Green 143 C.
[0068] [0068] Flowering Response(photo-periodic.— 52 Days controlled crop, not natural season.
[0069] Foliage
[0070] [0070] Color mature.— Upper side green 137 A. Under side green 137 D.
[0071] [0071] Color immature.— Upper side green 137 A. Under side green 137 D.
[0072] [0072] Size.— Small; length 5.5-6.0 cm, width 4.5-5.0 cm.
[0073] [0073] Quantity(number per lateral.— 8-10 branch).
[0074] [0074] Shape.— Round and lobed.
[0075] [0075] Texture upper side.— Glabrous.
[0076] [0076] Texture under side.— Pubescent.
[0077] [0077] Venation arrangement.— Palmate.
[0078] [0078] Shape of the margin.— Serrated.
[0079] [0079] Shape of Base of Sinus Between.— Acute Lateral Lobes.
[0080] [0080] Margin of Sinus Between Lateral.— Diverging Lobes.
[0081] [0081] Shape of Base.— Acute.
[0082] Apex.—Cupidate.
Differences with the comparison varieties When grown under the same conditions ‘McBrian’ ‘Visalia’ Flower color Red-purple 71A Purple 75C Flower size 4.0-4.5 cm 5.0-5.5 cm Growth habit upright spreading Foliage size small medium | A Chrysanthemum plant named ‘MC BRIAN’ characterized by its small sized blooms with dark purple ray-florets and greydisc florets. | 0 |
RELATED PATENT DATA
[0001] This patent claims priority to U.S. Provisional Patent Application No. 60/547,485, which was filed Feb. 25, 2004.
TECHNICAL FIELD
[0002] The present invention relates to alternators.
BACKGROUND OF THE INVENTION
[0003] Alternator design is known in the art. It is a fundamental principle of physics that when a magnet rotates in a wire loop, a current is induced. A magnet has a south pole and a north pole. Assume that the north pole is just passing a top part of the wire loop and the south pole is just passing the bottom part of the loop. When the magnet has rotated through 180 degrees, the south pole will be passing the top part of the loop while the north pole will be passing the bottom part of the loop. This causes the direction of induced current to be reversed. In this way, alternating current is induced in each turn of wire in a stator of an alternator.
[0004] In an alternator, a rotor is spun inside a stator. The stator includes multiple windings of wire. A single turn would not induce enough voltage nor carry enough current for typical applications of an alternator. Therefore, a practical alternator has a stator with many turns of wire.
[0005] The rotor defines an electromagnet that provides a magnetic field that is spun inside the windings of wire to generate current. A relatively small field current used to define the electromagnet is supplied to the rotor by two small brushes that each ride on separate and continuous slip rings. Field current passes through the brushes into the slip rings into the rotor.
[0006] There are typically three separate windings of wire in the stator arranged so that the AC (alternating current) that is generated by each winding is slightly out of phase compared to the other windings. This smoothes the electrical output of the alternator.
[0007] A rectifier circuit including diodes is used to convert the AC to DC (direct current). The diodes are arranged so that current from each of the three stator wires is only allowed to pass in one direction, and the three outputs are connected together. A voltage regulator is typically provided to the DC output to keep the output voltage relatively steady. The voltage regulator can be a mechanical or solid state device.
[0008] For externally regulated alternators, there are typically four connections on the alternator: the output terminal (often labeled BAT), the ground terminal (often labeled GRD) or ground may be “implied” though the metal mountings of the alternator, the field connection (often labeled F), and separate connections to each of the three poles on the stator (R).
[0009] Internally regulated models also have four connections, but the voltage regulator is inside the alternator and constructed of solid-state components. For internally regulated alternators, the connections are: an output terminal (typically labeled BAT), a ground terminal (typically labeled GRD) or ground may be “implied” though the metal mountings of the alternator, and two connections typically labeled 1 and 2 . One of these connections is a relatively small wire that is connected to a battery and the other is connected to a charge indicator light.
[0010] Brushes that ride against the slip rings of the rotor of an alternator are components that are likely the number one failure mode of an alternator since the brushes wear out over time due to friction. Such brushes are conventionally internal, and are housed inside the housing of an alternator. For conventional alternators, in order to changes brushes, the alternator must be removed from service and substantially disassembled. The brush blocks then have to be removed from inside of a rear shell housing component after the rear shell has been removed from the rest of the alternator.
[0011] Certain alternators are known in the art that have removable, externally accessible, brush blocks. However, in these designs, the brushes extend out past the end of the main housing. In these designs, the rear bearings of the alternator are axially inside of the slip rings and the brushes.
[0012] Certification of components for aircraft use is a lengthy process. Components used in alternators for aircraft have subtle differences when compared with alternators used in automobiles in view of the different environments in which they are used and more serious consequences of failures in aircraft environments. For example, different brush materials are used for alternators used in aircraft than the material used in automotive alternators.
[0013] An aircraft alternator designed to deliver a certain level of amperage cannot simply be used on an airplane designed for a lower amperage alternator. For example, an 80 Amp alternator cannot be used on a 40 Amp airplane even though a regulator will regulate the current down to 40 Amps. The problem is that aircraft wiring is typically geared around the maximum rating of the alternator.
[0014] For example, forty years ago, when some of these planes were built, 40 Amp alternators were the biggest alternators available. Therefore, the gauge of the wiring going from the alternator was geared around that rating. If higher amperage current, such as 80 Amps, was passed through, the wiring could burn up. Provided that the regulator is working correctly, this would not happen. However, regulators sometimes fail and fields sometimes short. Safety standards for aircraft dictate that an aircraft alternator cannot be capable of putting out more than the designated current. This means that different alternator designs are used in different aircraft, causing manufacturers to manufacture multiple different types of alternators and causing vendors and repair facilities to stock multiple different types of alternators.
SUMMARY OF THE INVENTION
[0015] Embodiments of the invention provide an alternator with a removable brush block. Other embodiments provide an alternator with a replaceable resistor in series with the field.
[0016] One aspect of the invention provides a method of changing the maximum current output of an alternator, in view of aircraft safety standards requiring that alternators for aircraft not be able to put out more than a predetermined amperage, notwithstanding the ability to regulate current with a regulator outside of the alternator. Other methods and apparatus are also provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Preferred embodiments of the invention are described below with reference to the following accompanying drawings.
[0018] FIG. 1 is a perspective view of an alternator in accordance with various embodiments of the invention.
[0019] FIG. 2 is a cut away perspective view of the alternator of FIG. 1 .
[0020] FIG. 3 is an exploded perspective view of a housing portion, brush holder, and holder plate, of the alternator of FIGS. 1 and 2 .
[0021] FIG. 4 is a view of the brush holder of FIG. 3 , assembled to the holder plate of FIG. 3 , and together removed from the alternator of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8).
[0023] As mentioned above, brushes that ride against the slip rings of the rotor are perhaps the number one failure mode in alternators. They wear out. Therefore, besides making them as strong and as long lasting as possible, they are made to be easily interchanged.
[0024] With standard alternators, and with all or substantially all aviation alternators, in order to change out brushes, substantially the whole alternator has to be disassembled to replace the brushes.
[0025] FIG. 1 shows an alternator 10 embodying various aspects of the invention. In the embodiment of FIG. 1 , the alternator 10 is an aircraft alternator. The alternator 10 includes a housing 12 . In the illustrated embodiment, the housing 12 includes a front case portion 14 ( FIG. 2 ), and a rear case portion 16 having a plurality of electrical connectors for inputs and outputs. The housing further includes an aperture or material removed portion 20 ( FIG. 3 ).
[0026] The alternator 10 includes a stator 22 ( FIG. 2 ) supported in the housing 12 . More particularly, in the illustrated embodiment, the stator 22 is at least partially supported by the front case portion 14 of the housing and the rear case portion 16 can be removed from the front case portion 14 without removing the stator 22 . The alternator 10 further includes a rotor 24 ( FIG. 2 ), including slip rings 26 and 28 , and including a rotor shaft 30 configured to rotate about an axis 32 . The shaft has opposite ends 34 and 36 .
[0027] The alternator 10 further includes front and rear bearings 38 and 40 respectively supporting the ends 34 and 36 of the rotor shaft 30 in the housing 12 for rotation relative to the stator 22 .
[0028] The alternator 10 further includes a removable assembly 42 ( FIG. 2 ) including a support member or holder plate 44 and a brush holder 46 ( FIG. 3 ). The brush holder 46 includes brush blocks 48 and 50 ( FIG. 2 ) configured to slidingly support brushes 52 and 54 ( FIG. 4 ). The term brush block, as used herein, refers to any structure configured to support a brush. In the illustrated embodiment, the brush blocks 48 and 50 are each defined by a cartridge or chamber that slidingly receives a brush and a spring. More particularly, in the illustrated embodiment, the brushes 52 and 54 are biased by springs in the cartridges 48 and 50 into engagement with the slip rings 26 and 28 . The brushes 52 and 54 are electrically configured to pass a force current through the rotor 24 via the slip rings 26 and 28 . In the illustrated embodiment, the brushes 52 and 54 are each made of a special carbon used for aircraft applications. For example, for aircraft applications, aircraft grade brush material is used for high altitude applications.
[0029] The brush holder 46 ( FIGS. 3 and 4 ) is removably supported by the support member 44 . The removable assembly 42 is selectively fixed relative to the rear case portion 16 of the housing against movement relative to the front case portion 14 of the housing when in a “in use” position. When in the “in use” position, the brushes 52 and 54 engage the slip rings 26 and 28 and the support member 44 at least partially closes the aperture or material removed portion 20 ( FIG. 3 ).
[0030] The support member 44 has an inside surface 56 ( FIG. 2 ) configured to face inside the housing 12 , when the removable assembly 42 is in the “in use” position, and an outside surface 58 configured to face away from the alternator 10 , when the removable assembly 42 is in the “in use” position. The brush blocks 48 and 50 are mounted to, covered by or positioned by the inside surface 56 . In the illustrated embodiment, the brush holder 46 is mounted to and movable with the support member 44 . The outside surface 58 supports a force terminal 60 which is electrically coupled to one of the brushes 52 , 54 . In the illustrated embodiment, the force terminal 60 is defined by an electrically conductive post extending away from the support member 44 .
[0031] In some embodiments, the support member 44 has a surface 62 configured to mate with the material removed portion or aperture 20 to close the aperture 20 when the removable assembly 42 is in the use position. Alternatively, the support member 44 overlaps or covers the aperture 20 either completely or partially.
[0032] The slip rings 26 and 28 are located ( FIG. 2 ) between the bearings 38 and 40 with respect to the axis 32 defined by the rotor shaft 30 . More particularly, in the illustrated embodiment, the brushes 52 and 54 ( FIG. 4 ) are internal of the housing 12 and the slip rings 26 and 28 are internal of the housing 12 . Still more particularly, in the illustrated embodiment, the rear bearings 40 are axially outside of the slip rings 26 and 28 , and the slip rings 26 and 28 are on the inside of the housing 12 , yet removable brush blocks 48 and 50 are provided. There are advantages to this design. The farther apart the front bearings 38 are located from the rear bearings 40 , the more stable the rotation will be. Also, this design gives better protection to the slip rings 26 and 28 .
[0033] The removable assembly 42 is removable from the rear case portion 16 of the housing 12 from outside the housing 12 (e.g., with a hand tool such as a screwdriver), without the need to remove the rear case portion 16 of the housing 12 from the front case portion of the housing 14 .
[0034] In the embodiment of FIG. 1 , to remove the removable assembly 42 and the brush blocks 48 and 50 , a user removes fasteners 64 ( FIG. 3 ) that hold the removable assembly 42 in the housing 12 , from outside the housing 12 , removes the removable assembly 42 , replaces the assembly 42 with a new assembly 42 (or replaces the brushes 52 and 54 within the assembly), and refastens the new or upgraded assembly to the housing 12 . A removable pin 68 ( FIG. 4 ) holds the brushes 52 and 54 in the brush blocks 48 , against the bias of springs in the brush blocks 48 and 50 , until the removable assembly 42 is replaced. After the removable assembly 42 is replaced, the pin 68 is removed from the removable assembly 42 , allowing the brushes 52 and 54 to extend from the brush blocks 48 , 50 into engagement with the respective slip rings 26 , 28 . In the illustrated embodiment, the fasteners 64 are screws; however, other appropriate fasteners could be used.
[0035] The field current passes through the brush 52 or 54 into the slip ring 26 or 28 , and into the rotor 24 . That applies power to the rotor 24 , creating the magnetic field of the rotor 24 that causes the generation of energy in the stator 22 .
[0036] Typically, alternators are designed such that field current is transmitted generally directly to the rotor. In the illustrated embodiment, the alternator 10 is capable of a predetermined current output. For example, in the illustrated embodiment, the alternator 10 is an aircraft alternator capable of outputting up to about 80 Amps. However, there are aircraft that have different maximum current ratings. For example, some aircraft need 40 Amp alternators, some need 60 Amp alternators, and some need 70 Amp alternators.
[0037] Therefore, in some but not all embodiments, the removable assembly 42 further supports a resistor 66 ( FIG. 4 ) configured to reduce current provided to the rotor 24 . More particularly, in the illustrated embodiment, the resistor 66 is easily removable and replaceable. Still more particularly, in the illustrated embodiment, the resistor 66 is removable from the housing 12 with the brush blocks 48 and 50 .
[0038] The resistor 66 is placed in-line with the field current. For example, in some embodiments, the resistor 66 is electrically coupled between the force terminal 60 and one of the brushes 52 and 54 . More particularly, the resistor 66 is removably attached to the inside surface 56 of the support member 44 . Field current travels from externally of the alternator 10 through the post or terminal 60 , through this resistor 66 , and then to a brush 52 or 54 .
[0039] Depending upon the resistance value of the resistor 66 that is used, a different model alternator 10 is created for use on an aircraft that uses a certain ampere alternator. In the illustrated embodiment, the brush blocks 48 , 50 are replaceable with brush blocks supporting resistors 66 that are appropriate to define a 40, 60, or 70 Amp alternator. Alternatively, the resistor 66 could be removed and replaced with a conductor or bypassed with a jumper to define an 80 Amp alternator. In fact, the same alternator 10 could be adapted to any ampere rating (lower than its maximum output) by replacing the resistor 66 . The resistor 66 is on the input or field end of the circuit. By reducing the amount of current going into the alternator 10 , the amount of magnetism produced is reduced by the resistor 66 .
[0040] This design saves expense in manufacturing and in stocking of alternators.
[0041] In some embodiments, the alternator case or housing used is a Delco™ 10DN case. Alternative housing styles could also be employed.
[0042] In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents. | An alternator comprises a housing including a first portion, and a second portion having a plurality of electrical connectors and having an aperture; a stator supported in the first portion of the housing; a rotor supported for rotation relative to the stator and configured to have a force current applied thereto; and a resistor coupled to the rotor and configured to reduce the current through the rotor, the resistor being removable and replaceable. Other apparatus and methods are provided. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to computer communication, and deals more particularly with a technique, system, and computer program for maintaining session-related state information in a scalable, clustered network environment. This is preferably done in a manner that avoids the need to use persistent storage such as a database to store session information, thereby removing the performance penalty associated with database accesses. Further, a mechanism is provided whereby the integrity of the session data is protected from inadvertent overwriting. The technique is provided using industry-wide, standard APIs, allowing for increased portability, scalability, and acceptance of this solution.
2. Description of the Related Art
The Internet is a vast collection of computing resources, interconnected as a network, from sites around the world. It is used every day by millions of people. The World Wide Web (referred to herein as the "Web") is that portion of the Internet which uses the HyperText Transfer Protocol ("HTTP") as a protocol for exchanging messages. (Alternatively, the "HTTPS" protocol can be used, where this protocol is a security-enhanced version of HTTP.)
A user of the Internet typically accesses and uses the Internet by establishing a network connection through the services of an Internet Service Provider (ISP). An ISP provides computer users the ability to dial a telephone number using their computer modem (or other connection facility, such as satellite transmission), thereby establishing a connection to a remote computer owned or managed by the ISP. This remote computer then makes services available to the user's computer. Typical services include: providing a search facility to search throughout the interconnected computers of the Internet for items of interest to the user; a browse capability, for displaying information located with the search facility; and an electronic mail facility, with which the user can send and receive mail messages from other computer users.
The user working in a Web environment will have software running on his computer to allow him to create and send requests for information, and to see the results. These functions are typically combined in what is referred to as a "Web browser", or "browser". After the user has created his request using the browser, the request message is sent out into the Internet for processing. The target of the request message is one of the interconnected computers in the Internet network. That computer will receive the message, attempt to find the data satisfying the user's request, format that data for display with the user's browser, and return the formatted response to the browser software running on the user's computer.
This is an example of a client-server model of computing, where the machine at which the user requests information is referred to as the client, and the computer that locates the information and returns it to the client is the server. In the Web environment, the server is referred to as a "Web server".
The HTTP communications protocol uses a request/response paradigm, where the electronic messages sent between communicating computers can be categorized as either requests for information, or responses to those requests, as illustrated above. HTTP does not provide for maintaining any type of state information about the communications, instead treating each request/response pair as a separate and unrelated transaction. This approach works well for many Web transactions. For example, a user may request to see a specific document displayed on his browser. When it has been sent by the server and displayed to the user, there may be no further processing that relates to that request, and therefore nothing more to be done. However, there are many instances where this absence of state information is a serious shortcoming of the protocol. When there is no state information, then a server receiving requests from a client may have no way of knowing that it has received prior requests from this same client, and no way of making any type of logical connection between the multiple requests.
Some example scenarios where state information is an absolute necessity include on-line shopping, searching with successive refinement of search terms, and gathering user profile information. In on-line shopping, a user typically accesses a seller's on-line catalog, which will be displayed to him as some number of Web pages (where a "Web page" is the information displayable in response to a user's request). Typically, the user can display a separate page of information related to each product, to read about the details of that product. Each time the user requests to see a page, a separate HTTP request is typically sent to the Web server where the seller's product catalog is stored. This request indicates that data for a specific product should be gathered and sent to the client machine for display. When the user wishes to order a product, he indicates his selection by clicking on an "Order" button of some type, using a mouse, for example. This causes another request message to be sent to the server, where the request indicates that this is an order for the particular item. Without the ability to maintain state information, each of these requests would be treated as unrelated to the others. There would be no efficient way to collect orders for more than one item into one large order. Further, there would be no efficient way to allow the user to enter his name, address, credit card number, etc. only one time, and have that information apply to all the ordered items.
Searching for information, and then applying refinements to the search criteria, would suffer from the same inconveniences in the absence of state information. Obviously, users would not long tolerate shopping or searching in this way, so various methods of adding state information to HTTP's state-less environment have evolved. A typical approach to the searching scenario is to embed the search criteria into the URL (Uniform Resource Locator) of both the HTTP request and the response. Thus, when the user is viewing the result of his search criteria, those criteria are still available and can be further refined in a subsequent search message created from the text of this search. This carrying-along of the state-related information is not a viable approach in more detailed and complex examples such as on-line shopping, however. To deal with keeping larger amounts of data between related messages, the concept of a "session" has been introduced.
Sessions have been used for many years in other types of environments that preceded HTTP and the Web, and which were state-oriented. For example, the Systems Network Architecture ("SNA") from the International Business Machines Corporation ("IBM") is a state-oriented architecture and protocol. The Open Systems Interconnection ("OSI") architecture and protocols are also state-oriented. In these architectures, a session is a temporary logical connection over which two communicating entities send messages. Certain attributes are associated with the session, such as identifying information for each of the entities. These types of information are state-related information.
This session approach has been added to HTTP transactions by associating a Session Identifier ("Session ID") with each client. A session ID may be any type of identifier that serves to uniquely identify a particular client to the server. This session ID is then sent as part of the HTTP request syntax for each message sent from the client machine. The server uses the session ID to store information related to the transactions with this client, so that the series of transactions can be treated as a logical on-going communication between the client and the server (instead of simply as random, unrelated messages). This is how the server is able to accumulate the information required for a user to perform on-line shopping, and is also how servers can gather information about users that becomes part of a user's profile. The session then encompasses all requests from this client that use this same identifier.
Session IDs have been implemented on top of HTTP using two primary approaches. The first is through use of "cookies". The second is through "URL rewriting". A cookie is an abstract concept referring to storing state information, and passing a reference to that information between the client and server by including an identifier in the HTTP request and responses. When a client issues a first request to a server, the server will create a cookie for this client, and assign a session ID to the cookie. The cookie for the session is then passed back to the client with the response. On the client's subsequent requests, the client sends the session cookie as part of the request. A server typically provides services to many clients, and receiving the client's session identifier as a cookie enables the server to find the information it has kept about previous transactions with this particular client. Transferring the state information in this way allows the client and server to maintain state-related information. However, some browsers do not support cookies as part of the HTTP syntax, or they may allow users to disable cookie support, so the URL rewriting mechanism can be used instead. URL rewriting is a way of ensuring that requests sent to the server will have the session ID plugged into the URL. Web pages that are sent to the client machine often have hypertext links embedded in them. A hypertext link is an address the user can click on from the page, which may cause a request for a different page to be sent to the server. By putting the session ID into the address in that link, the server can maintain state information for the session. Processing by the server is required for rewriting the URLs. That is, before the server sends a page to a client, the server will check to see if the page has URLs embedded in it. If so, the server adds a session ID parameter and the unique identifier for this session into the URL syntax before sending the page.
The Java language is gaining wide acceptance for writing Web applications, as it is a robust portable object-oriented language defined specifically for the Web environment. ("Java" is a trademark of Sun Microsystems, Inc.) Web servers that implement a Java Virtual Machine can be functionally extended using Java "servlets". A servlet is a relatively small executable code object that can be dynamically plugged in, or added, to the code running on the server. Servlets typically perform some specialized function, which can be invoked by the server (or by another servlet) to extend its own functionality. The servlet processes the request, and returns the response to the server (or servlet) that invoked it. Any number of servlets can be running within one server at any given time.
The Java Web Server Toolkit from Sun Microsystems now provides a mechanism called Session Tracking, whereby state information can be maintained and made available to servlets. The state information is stored on the server using a session object. This object is created when a new client session begins, and is kept for the duration of the session. The object stores information about the transactions occurring between the client and the server. An interface to the object is defined so that servlets can access and modify the state information to reflect the transactions they process for that client. The session ID concept is used to correlate a particular session object to the proper client. This session tracking mechanism supports both cookies and URL rewriting for passing the session ID between the client and server (and subsequently to servlets). The session object has some predefined fields for which it will store values. Additional data can be stored with a developer-defined identifier, which can then be used to access the stored data later on.
A number of difficulties exist with session tracking as it is provided, however. The documentation for the Java Web Server Toolkit warns that developers should adopt a naming convention in order to avoid overwriting servlet data values, since an object is shared among servlets. Refer to "Java Web Server 1.1--Session Tracking", located at URL "http://jserv.javasoft.com/products/java-server/documentation/webserver1.1/session -- track/SessionTr.html". Further, a limit is placed on the number of sessions that can exist in memory at any one time. This limit is discussed in the same documentation. A limit is used because a very large number of sessions can be active on a particular server, and the session object for each session can grow to an unpredictable size due to the fact that servlets can add any type of information to the object that they need for their function. The limit is implemented with a system variable (referred to as a "property") that specifies the maximum number of memory-resident sessions, and a swapping mechanism that swaps the least-recently used session objects to a disk file when the maximum number is exceeded. The session objects will then be swapped back into memory as they are needed. The swapping carries the performance penalty associated with writing to disk files, and also requires the developer to structure data objects added to the session object so that they are serializable. "Serializable" refers to defining a linear structure for a non-linear object, by which the non-linear object can be written to a linear data stream such as a disk file. Any structures of the session object that are not defined as serializable will not be written to disk when the rest of the object is swapped out. They remain in memory, thus restricting the amount of memory made available for new sessions by the swapping operation.
A common practice for scaling and increasing the capacity of Web servers and Web sites is to increase the number of computer hosts (servers) which perform HTTP processing. These groups of Web servers are shielded by a load-balancing host (such as IBM's Interactive Network Dispatcher) which directs HTTP requests to different Web servers in its pool of servers to spread out the demand. A pool, or group, of servers is also referred to as a cluster of servers. When session services are provided at these clustered servers, the group of sessions can logically be thought of as a pool, or cluster, of sessions. Since the Session Tracking facility in the Java Web Server Toolkit is only valid within the scope of a single Web server, the pool of sessions cannot be properly maintained among a group of clustered Web servers such as this. For example, if a client request is received at one server, and that server maintains information about the on-going session, there is no way for this version of the session information to be made available to a different server in the cluster if the next request from this client goes to a different server.
Accordingly, a need exists for a technique by which these shortcomings in the ability to provide session services in a clustered environment can be overcome. A technique is needed to ensure that servlets do not inadvertently overwrite each other's data that is being created for session state information, while still allowing those servlets to share each other's data. The database access performance penalty must be removed to enable servlets to function optimally. Further, to ensure wide acceptance of a solution, the technique must be portable and must use non-proprietary interfaces. The proposed technique uses a plug-in servlet engine to maintain session information among multiple computers for servlets in a clustered environment, and to provide session services to the servlets. Session information is maintained without using a persistent data store according to the preferred embodiment of this technique. Further, the proposed technique provides a locking mechanism for each session object, to ensure the integrity of the state information contained in the session objects. These benefits are provided using widely-available, non-proprietary features of an Application Programming Interface ("API") such as the Java API and Java Servlet API, allowing for scalability, portability, and maximum industry acceptance of this solution.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a technique whereby session information can be maintained among multiple computers for servlets in a scalable, clustered network environment, providing those servlets with session services.
Another object of the present invention is to provide a technique whereby this session information is maintained without use of persistent storage such as a database.
It is another object of the present invention to provide the session services in a way that protects the integrity of the session information such that servlets do not inadvertently overwrite each other's data.
It is a further object of the present invention to provide these benefits using widely-available, non-proprietary code interfaces, in order to maximize acceptance of the present solution.
Other objects and advantages of the present invention will be set forth in part in the description and in the drawings which follow and, in part, will be obvious from the description or may be learned by practice of the invention.
To achieve the foregoing objects, and in accordance with the purpose of the invention as broadly described herein, the present invention provides a software-implemented process for use in a computing environment having a connection to a network, for managing session-related state information in a clustered server environment, comprising at least one client request; one or more servers; one or more servlets; and one or more servlet engines, each of the engines running in a different one of the servers. Each of the servlet engines comprises a subprocess for configuring the servlet engine, wherein the servlet engine may be configured as a session client or a session server; a subprocess for receiving a client request when the client request is destined for one of the servlets; a subprocess for making any necessary updates to the client request; and a subprocess for forwarding the updated client request to the servlet. The servlet engine configured as a session server further comprises a subprocess for maintaining a plurality of session objects; a subprocess for locating one of the session objects in response to a request from one of the servlets or one of the session clients; and a subprocess for returning the located session object in response to the request. Preferably, the servlet engine configured as a session server further comprises a subprocess for controlling access to the session objects using a locking mechanism. A servlet engine configured as said session client further comprises a subprocess for requesting one of the session objects from the session server; a subprocess for receiving the requested session object; and a subprocess for returning the session object to the session server after processing. Optionally, the session server can be optimized for providing session services by not having application servlets running on the server on which the session server is running. Further, a servlet engine configured as a session client further comprises a subprocess for sending updates for session objects to the session server. Optionally, each of the servlet engines further comprises a subprocess for requesting a list of all valid session identifiers from the session server; a subprocess for requesting the session object for any of the session identifiers from this list; a subprocess for updating the requested session object; and a subprocess for returning the updated session object to the session server for reflecting the updates. Preferably, the session-related state information is maintained without use of a persistent data store, and the code uses standard Application Programming Interface ("API") calls. These API calls may use Remote Method Invocation to achieve transparency at an invoking servlet. Further, a central copy of session-related configuration data can be propagated from the session server to all of the session clients. This optionally includes having each of the session clients register with the session server to enable the propagation to occur whenever the configuration data changes.
The present invention will now be described with reference to the following drawings, in which like reference numbers denote the same element throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer workstation environment in which the present invention may be practiced;
FIG. 2 is a diagram of a networked computing environment in which the present invention may be practiced;
FIG. 3 illustrates a model of the clustered server environment in which the present invention may be practiced, showing the addition of the plug-in servlet engine and its relationship to Web servers and servlets; and
FIGS. 4A, 4B and 4C illustrate a flow chart which sets forth the logic involved with the present invention to use and update session information.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a representative workstation hardware environment in which the present invention may be practiced. The environment of FIG. 1 comprises a representative computer or intelligent workstation 10, such as a personal computer, including related peripheral devices. The workstation 10 includes a microprocessor 12 and a bus 14 employed to connect and enable communication between the microprocessor 12 and the components of the workstation 10 in accordance with known techniques. The workstation 10 typically includes a user interface adapter 16, which connects the microprocessor 12 via the bus 14 to one or more interface devices, such as a keyboard 18, mouse 20, and/or other interface devices 22, which can be any user interface device, such as a touch sensitive screen, digitized entry pad, etc. The bus 14 also connects a display device 24, such as an LCD screen or monitor, to the microprocessor 12 via a display adapter 26. The bus 14 also connects the microprocessor 12 to memory 28 and long-term storage 30 which can include a hard drive, diskette drive, tape drive, etc.
The workstation 10 communicates via a communications channel 32 with other computers or networks of computers. The workstation 10 may be associated with such other computers in a local area network (LAN) or a wide area network, or the workstation 10 can be a client in a client/server arrangement with another computer, etc. All of these configurations, as well as the appropriate communications hardware and software, are known in the art.
FIG. 2 illustrates a data processing network 40 in which the present invention may be practiced. The data processing network 40 includes a plurality of individual networks, including LANs 42 and 44, each of which includes a plurality of individual workstations 10. Alternatively, as those skilled in the art will appreciate, a LAN may comprise a plurality of intelligent workstations coupled to a host processor.
Still referring to FIG. 2, the data processing network 40 may also include multiple mainframe computers or servers, such as a mainframe computer 46, which may be preferably coupled to the LAN 44 by means of a communications link 48. The mainframe computer 46 may be implemented utilizing an Enterprise Systems Architecture/370, or an Enterprise Systems Architecture/390 computer available from IBM. Depending on the application, a midrange computer, such as an Application System/400 (also known as an AS/400) may be employed. "Enterprise Systems Architecture/370" is a trademark of IBM; "Enterprise Systems Architecture/390", "Application System/400", and "AS/400" are registered trademarks of IBM.
The mainframe computer 46 may also be coupled to a storage device 50, which may serve as remote storage for the LAN 44. Similarly, the LAN 44 may be coupled to a communications link 52 through a subsystem control unit/communication controller 54 and a communications link 56 to a gateway server 58. The gateway server 58 is preferably an individual computer or intelligent workstation which serves to link the LAN 42 to the LAN 44.
Those skilled in the art will appreciate that the mainframe computer 46 may be located a great geographic distance from the LAN 44, and similarly, the LAN 44 may be located a substantial distance from the LAN 42. For example, the LAN 42 may be located in California, while the LAN 44 may be located in Texas, and the mainframe computer 46 may be located in New York.
Software programming code which embodies the present invention is typically accessed by the microprocessor 12 of the workstation 10 from long-term storage media 30 of some type, such as a CD-ROM drive or hard drive. In a clustered Web server environment, such software programming code may be stored with storage associated with a server. The software programming code may be embodied on any of a variety of known media for use with a data processing system, such as a diskette, hard drive, or CD-ROM. The code may be distributed on such media, or may be distributed from the memory or storage of one computer system over a network of some type to other computer systems for use by such other systems. Alternatively, the programming code may be embodied in the memory 28, and accessed by the microprocessor 12 using the bus 14. The techniques and methods for embodying software programming code in memory, on physical media, and/or distributing software code via networks are well known and will not be further discussed herein.
The session services facilities implemented in a plug-in servlet engine resulting from use of the present invention may be stored on any of the various media types used by the long-term storage 30. This code will typically be installed in a server 46, which processes requests that come from a user having a computer such as the workstation 10.
While servers in Web environments may not typically include a display device 24, the preferred embodiment of the present invention uses a display device 24 in order to allow the plug-in servlet engine to be configured, for example by a system administrator.
The preferred embodiment of the present invention will now be discussed with reference to FIGS. 3 and 4.
In the preferred embodiment, the present invention is implemented as a computer software program. This program will be used where a client has sent a request for data to a server, and comprises part of the processing done on the server side of the network. Typically, the program will be used in an Internet environment, where the server is a Web server and the request is formatted using HTTP (or HTTPS). Alternatively, the connection may be to a corporate intranet (that is, a network owned or managed internally to the user's company) of which the user's computer is a component, where this corporate intranet provides services in a similar manner to the Internet. Use of the term "Internet" herein, when discussing processing associated with the user's request, includes processing that occurs in an intranet, unless otherwise stated. The program code of the preferred embodiment will be implemented as objects in an object-oriented programming language such as Java, which are incorporated along with other objects of a plug-in servlet engine object to run as executable programs. However, the inventive concepts of the present invention are not limited to implementation in an object-oriented environment, nor to implementation in the Java language.
FIG. 3 illustrates a model of the clustered server environment in which the present invention may be practiced, and shows how this invention interacts with other components of the environment. A Web server 60 may be connected to any number of other Web servers, shown here as 62 and 64. Clustering multiple servers in this way provides for increased capacity with which HTTP requests at a Web site can be processed. A load-balancing host 59 functions as a type of front-end processor to these servers, receiving client requests 100, 101, 102 and then routing those requests (shown here as 110, 111, 112) to a server selected according to policies implemented in the load-balancing host software. Note that the requests 110, 111, 112 are shown being sent to specific Web servers: this is merely an example of a possible outcome of the load balancing process. Load-balancing techniques are known in the art, and do not form part of the present invention.
The present invention solves the previously-discussed problem of not being able to extend session services support to this clustered server environment. This is accomplished by providing session services management features in a plug-in servlet engine, which is executable code that extends the functionality of the Web server. One of these servlet engines will be installed on each Web server that will participate in this session-management solution. One of the servlet engines will be configured to function as a Session Server, and the others will be configured to function as Session Clients. See FIG. 3, where a plug-in servlet engine 70, 72, 74 which embodies the present invention is used with each of the Web servers (60, 62, 64 respectively), and the servlet engine 70 in Web server 60 is designated as the session server. According to the preferred embodiment of the present invention, any servlet engine can be chosen to function as the session server, and the assigned roles (i.e. server or client) can be changed using a configuration process. Thus, no specialized servlet engine is required. This solution maximizes efficiency of the present invention, whereby a different servlet engine can take over the session server role if an outage occurs at the prior session server. The manner in which this configuration is performed does not form part of the present invention. Preferably, the system administrator will be prompted by a configuration routine to specify which servlet engines are to function as session clients, and which is to function as a session server.
The configuration process may also allow a servlet engine to be configured as neither a session server nor a session client, for the situation in which the servlet engine is not currently operating as part of a clustered environment. In this "stand-alone" mode, the servlet engine is not using the inventive concepts of the present invention. Thus, this scenario will not be discussed further.
Optionally, the operation of the session services feature can be optimized by restricting the servlet engine functioning as the session server to providing only session services during the time in which it is the session server. In that case, no servlets would be invoked from the associated server, and thus the servlets shown as 90, 91 in FIG. 3 would not be used while servlet engine 70 was the session server. When no servlets are invoked, no servlet-created objects get stored into the server's memory, and thus the amount of memory available for managing session services is maximized. This would be accomplished by configuring the load-balancing host policies to not route client requests to this servlet engine while it functions as a session server.
A servlet engine may provide any number of facilities for use by the servlets. The session services facility of the present invention is one example, and is shown as session server 80 and session clients 82, 84, each of which resides inside their respective servlet engines (as shown). Any of the Web servers may invoke the services of a servlet available to that server, shown here as servlets 90, 91, 92, 94, to perform specific processing of a client's request. The manner in which a Web server determines that a servlet should be invoked, and in which that invocation occurs, are known in the art and do not form part of the present invention. Further, the manner in which the Web servers communicate with one another is done according to well-understood techniques, and does not form part of the present invention. In the preferred embodiment, a plug-in servlet engine which embodies the session management facility of the present invention is added to the executable code running on the Web server by the installation process of the plug-in. Preferably, this installation process modifies the configuration file of the Web server to redirect specific types of messages (including those destined for servlet processing) to this plug-in. Once installed, the system administrator can then designate one of the Web servers, and its associated servlet engine plug-in, as the session server.
When an HTTP request 100, 101, 102 from a client is sent from the load-balancing host 59 as request 110, 111, 112 to one of the Web servers 60, 62, 64, the request will be passed from the Web server to the plug-in servlet engine if it meets the criteria stored in the rewritten server configuration file. For example, if the Web server determines that servlet processing is required for this request, then a servlet-identifying string will appear as part of the host destination address in the URL. The configuration file will be used to recognize that this is a request going to a servlet, and will redirect it to the plug-in. This same technique applies to any of the servers in the clustered environment. For illustrative purposes, assume the request is sent to Web server 62, and is designated for processing by servlet 92.
When the plug-in servlet engine 72 gets the request 112, the request may or may not include a session identifier for a session with this client. If this is the first request of a new session, no session ID will be present. If this is a request of an existing session, then there will be a session ID included using either the cookie mechanism or URL rewriting, as discussed earlier. In the preferred embodiment, the servlet engine passes this request on to the proper servlet (that is, the one identified by the syntax of the URL in the HTTP request) by invoking the servlet's "service" method, which is the standard API used to communicate with a servlet according to the Java Servlet "HttpServletRequest" API definition. (Changes may be required before passing this request to the servlet. For example, if URL rewriting is used, the servlet engine will strip the session ID from the address in the URL before the request is forwarded.) The service method has a request object and a response object as parameters. These objects encapsulate data sent to and from the servlet 92. The servlet engine may make changes to the request before forwarding it to the servlet, for example by modifying the URL so that the proper servlet is identified by the address in the URL.
Note that specific method invocations (including parameters) are referenced herein. These method names refer to existing interface definitions that may be used when the present invention is implemented in the Java programming language, according to the Java API and Java Servlet API, and are given to aid in understanding the preferred embodiment. However, the inventive concepts of the present invention are not limited to using these specific method invocations.
The function of a servlet is application-specific. Some applications have a need to maintain session information (such as the on-line shopping application previously discussed), while others do not (such as the simple request for locating a Web page and displaying that page in a browser). If the servlet needs session-related information, the servlet developer will have coded session information accessing calls as part of the servlet code. The preferred embodiment of the present invention does not require the programmer to add any logic to the servlet code he has already written: the session services operate transparently from the servlet's point of view.
If a servlet is written not to use session-related information, the servlet will perform its specific processing, eventually finishing and returning its results to the server through the response object with which it was invoked. While the servlet may have been invoked with a valid session ID present in the request object, it will not have made use of that session. The features of the present invention by which session services are used by servlets are not applicable to this scenario, and this scenario will not be discussed further.
If session services are required for this servlet's application, then the session services features of the present invention are used. According to the present invention, a servlet in this scenario will include code to get the session object for this session, and update that object to reflect session information related to the servlet's processing. When the servlet processing is finished, the session object is returned to the session pool, where it can be accessed for subsequent transactions with this servlet or a different servlet in the clustered environment. In this way, the state of the session can be communicated among the clustered servers and their servlets.
FIG. 4 illustrates the logic used in the preferred embodiment to enable a servlet to get the session object, update that object, and return it to the pool. FIG. 4 further illustrates the logic whereby the present invention uses a locking technique to solve the previously-discussed problem of servlets inadvertently overwriting state information another servlet has stored in the session object.
Step 200 shows that the servlet receives control after its service method has been invoked from the plug-in servlet engine. As discussed earlier, a request object and a response object are passed as parameters.
According to the Java Servlet API, a getSession method is defined that can be invoked to retrieve session information from the request object. The servlet code invokes this getSession method at Step 210. A "create" flag, which is set to "true" in the preferred embodiment to indicate that a session should be created if one does not already exist, is passed as a parameter.
The getSession request will be sent to the session services feature of the servlet engine residing in the Web server with which this servlet is associated. At Step 300, the servlet engine receives control. The transfer from the logic in the leftmost column of FIG. 4 to the logic in the middle column represents that the location of the logic processing has changed. As indicated in FIG. 4, the logic in the leftmost column resides in the application servlet, the logic in the middle column resides in the servlet engine (functioning as a session client) associated with that application servlet, and the logic in the rightmost column resides in the servlet engine functioning as the session server (which may or may not be the same servlet engine of the middle column).
Step 310 indicates that different processing applies, depending on whether the servlet engine is executing as a session client or as a session server. If it is executing as a session client, then the client needs to communicate with the session server to get the session object from the session pool. Control transfers to Step 320 to begin this process. Otherwise, if this is a session server, control transfers to Step 400.
Step 320 indicates that, in the preferred embodiment, the session client will get configuration properties from the session server. There are a number of such session properties defined for use in the Session Tracking feature of the Java Servlet API. These properties include such things as the length of time for which a session can be inactive before it should be considered expired, and deleted from the system; how often to check for inactive sessions; whether cookies or URL rewriting is being used to implement session services; etc. When the session services feature of the plug-in servlet engine is executing as a session server, or when a single server exists (i.e. a non-clustered environment), this information is readily available from the server's properties (configuration) file. However, when the present invention is used to extend session tracking to the clustered server environment, it is possible that different servers may have different values for these properties. In order for the servers to operate in a consistent manner within the cluster, the present invention provides means for using a single, central set of values. According to the preferred embodiment, that set of values is the one stored in the session server's properties file. If the servlet engine is functioning as a session client, then that client's properties file is to be ignored, using the values from the session server's file instead. This session client will use the session server's properties for the sessions retrieved for this client's servlets, while those servlets are executing. For example, the session client will check for whether URL rewriting is active before attempting to retrieve a session ID from the URL. In this way, session services can be distributed among the various servlet engines.
The next step for the session client is to get the session object for this session, at Step 330. This is done by extracting the session identifier from the request object. In the preferred embodiment, the method getRequestedSessionId will return the identifier defined in the session tracking implementation. The session ID is then used to request the corresponding session object from the session server's session pool. The process by which this occurs is described below with reference to Steps 400 through 480.
Control reaches Step 400 when the session client has requested a specific session ID's object from the session server (Step 330), or when the comparison at Step 310 indicated that this application servlet's servlet engine was functioning as a session server. In the latter case, the session server will need to extract the session ID from the request object, as the session client did at Step 330.
Step 410 indicates that a global lock table of the preferred embodiment is checked to determine if this session's object is already locked by another servlet thread. The present invention uses locking and wait queues for the session objects, to ensure that access to the session objects is serialized, one servlet accessing a session object at a time. This is a solution to the previously-discussed problem of servlets being able to inadvertently overwrite each other's data. In the preferred embodiment, a two-tiered approach to locking is used, although the inventive concepts apply equally well to a single-tiered approach. The two tiers comprise a global locking table, where an entry is kept for each session object indicating whether the object is currently locked or unlocked. (Alternatively, entries may be kept only for session objects that are locked, with the absence of an entry indicating the status as being currently unlocked.) The second tier is a First-In, First-out (FIFO) queue for each session object, where the queue is used to keep track of servlet threads that are waiting for access to this session object. In the single-tiered approach mentioned previously, the FIFO queues would suffice to implement the locking function. In this approach, the FIFO queue would contain a first entry for the servlet process currently holding the lock, as well as subsequent entries for any waiting processes. Then, the locked or unlocked status for a particular queue would be determined by checking to see if the FIFO wait queue was empty (empty indicating that the object is unlocked). Mechanisms for implementing FIFO queues and locking are well known to one of ordinary skill in the art, and will not be explained in detail.
If the test at Step 410 is negative, indicating that the session is not locked, it is not necessarily available for use by the requesting application servlet. At Step 420, another test is made in the preferred embodiment, to account for the situation where a session may have become invalid (for example, the value of the session server's inactivity property may have been exceeded, indicating that the session has become inactive for too long and is no longer considered valid). If the session is not valid, then Step 430 generates events to notify the waiting threads. Otherwise, the session is still valid, and control transfers to Step 440, where the entry in the global lock table is updated to indicate that this servlet now has a lock on this session object. (Alternatively, in a single-tiered queuing approach, a first entry would be placed on the FIFO queue for this session object.)
At Step 450, the session object is returned to the requester by returning from the method invocation. The application servlet then begins executing again (shown as Step 220), and will update the session object during its processing, according to the code written by the servlet developer. At Step 230, the application has finished its processing, and returns to the servlet engine plug-in, with the request object's session object reflecting the changes made by the developer and the response object containing whatever output will be returned to the client browser. The servlet engine is shown as receiving control at Step 500.
If the test at Step 410 is positive, indicating that the session is already locked by another application servlet, control transfers to Step 460. At Step 460, an entry will be placed on this session's FIFO wait queue, indicating that this servlet is waiting for the object to be unlocked. As is understood by one of ordinary skill in the art, the processing of that servlet will suspend until the servlet's lock gets to the head of the FIFO queue and the object is unlocked. This is shown as the repeating test loop of Step 470, which asks whether the session object has become unlocked and available to this servlet (that is, this servlet was at the head of the queue). The manner in which this test is actually made does not form part of the present invention, but it will be obvious that the testing does not repeat continually. Polling may be done at intervals, or a notification event may be generated, etc. In the preferred embodiment, notification events are used. Such techniques are well known in the art.
Once the session object becomes unlocked and available for this servlet, control transfers to Step 480. To indicate that this servlet is no longer waiting, its entry is removed from the session object's FIFO wait queue. (In the single-tier approach, the lock entry would remain until processing had completed.) Control then transfers to Step 420, to determine whether the session is still valid.
Step 510 indicates that the processing is different, based on whether the servlet engine is executing as a session client or as a session server. If it is executing as a session client, then the client needs to communicate with the session server to send the session object back to the session pool. The test at Step 510 will have a negative response, and control transfers to Step 520. Otherwise, if this is a session server, control transfers to Step 540.
At Step 520, a synchronization method is invoked, passing the session object as a parameter, which causes the session server to receive control at Step 530. Use of this synchronization method allows the session client to send updates for the session object to the session server.
At Step 530, any fields in the session object the programmer is allowed to modify via method calls are carried over to the session server's copy of the given session object. Control then transfers to Step 540, where a test is made to determine if the FIFO wait queue for this session object is empty. If so, then at Step 550 the entry in the global lock table will be removed; otherwise, at Step 560 the next servlet process from the wait queue will be dispatched. It will be obvious to one of ordinary skill in the art that this dispatching process occurs according to the logic beginning at Step 470, where the logic applies to execution for a different waiting servlet thread.
In an optional feature of the present invention, a registration process may be used to optimize the distribution of the session server's configuration properties to the session clients. When used, this feature replaces the need for Step 320 of FIG. 4. The registration process comprises having each session client send a registration message (for example, using a method call such as "register (address)" as part of its initialization, where address is an identifier by which this session client can be located) to the session server. (The address of the session server is known to the session clients by a configuration parameter.) This registration process enables the session server to know the address of all the session clients, so that when an update occurs to the session configuration properties, the session server can automatically propagate the revised properties to each client (for example, by invoking a method such as "config (new -- data)").
In another optional feature of the present invention, the preferred embodiment uses Remote Method Invocation ("RMI") to enable the session service invocations to operate transparently from the application servlet's point of view. That is, the invocation will be serviced locally if appropriate, or dispatched to a remote server for processing, if that is appropriate.
RMI is a technique for distributed Java applications, whereby the methods of a remote Java object can be invoked from other Java virtual machines, even though the virtual machine may be operating on a different server than the one on which the object is located. This is accomplished by making a reference to the object available to the application that wishes to invoke one of the object's methods. The reference can be made available either by the application program looking up the object's location (using a method invocation), or by passing the reference information to the object as a parameter to the application. This reference is then used when invoking the object's method, and serves to automatically route the request to the proper location. While the preferred embodiment has been described using RMI, the inventive concepts of the present invention are not limited to use of this technique for method invocations.
In yet another optional feature of the present invention, a technique is defined whereby an application servlet running in a particular Web server may access and update session objects for sessions other than the one with which the application servlet was invoked. This may be useful in a number of situations. For example, statistical data can be gathered by the application servlet about all the servlets currently executing; the addresses of the Web pages from which the servlets were invoked can be gathered; user IDs associated with currently executing sessions can be gathered; etc. Or, the application may update the session objects associated with a number of servlets to cause a message to be written into the Web pages that will be returned to the client browsers. According to this technique, the application servlet invokes a method that sends a request to the session server, asking for the session IDs of all valid sessions. The session server retrieves this information related to its pool of sessions, and returns it to the requesting application servlet. The application servlet can then access each session ID in turn from this list (or perhaps select some subset of the session IDs that is of interest, depending on the needs of the application). For each selected session ID, the session object is retrieved by sending a request to the session server. The application servlet can then modify any fields of this object that can be updated by a method invocation as it processes its defined task. When the updates are finished, the application servlet invokes a synchronization method (as was done at Step 520 of FIG. 4), passing the revised session data to the session server. The session server then changes its copy of the appropriate session object. The locking mechanism discussed with reference to FIG. 4 can be used to ensure the session server changes the session object when no other thread is using it.
While the preferred embodiment of the present invention has been described, additional variations and modifications in that embodiment may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims shall be construed to include both the preferred embodiment and all such variations and modifications as fall within the spirit and scope of the invention. | A technique, system, and computer program for maintaining session information among multiple clustered computers for servlets and providing those servlets with various session services. The session services are implemented using a plug-in servlet engine. The session information is preferably maintained without using a persistent data store, to avoid performance penalties associated with storing information in persistent storage such as a database. A locking technique is implemented to prevent servlets from inadvertently overwriting each other's session object data. A registration process is preferably used, to optimize communication of configuration property changes. Non-proprietary interfaces are used, allowing for scalability, portability, and maximum industry acceptance of this solution. | 7 |
FIELD OF THE INVENTION
The present invention is related generally to a voltage regulator, and more particularly, to a temperature compensation device and method for a voltage regulator.
BACKGROUND OF THE INVENTION
Voltage regulators have been applied extensively in various electronic products as power supplies. In state-of-art voltage regulators, in order to prevent load from being damaged due to voltage spike of the output in transients, voltage droop function is adapted for diminishing the voltage spike on the load in transients. FIG. 1 schematically shows a conventional voltage regulator 100 with voltage droop function, in which driver 104 switches transistors 106 and 108 coupled in series between input voltage Vin and ground GND in response to pulse width modulation (PWM) signal provided by control circuit 102 . Thereby, inductor current IL is generated to charge output capacitor Co so that output voltage Vo is produced. In the control circuit 102 , from the voltage drop across current sense resistor Rs due to the inductor current IL flowing therethrough, current sense circuit 110 produces current sense signal
Ix = IL × Rs K , [ EQ - 1 ]
where K is the equivalent resistance of the current sense circuit 110 . The current sense signal Ix passes through droop resistor R ADJ and produces load line droop voltage
Vdroop=Ix×R ADJ . [EQ-2]
Because of virtual ground, the voltage on pin 116 intends to be equal to reference voltage Vref, and therefore the output voltage will be
Vo=Vref−Vdroop . [EQ-3]
Error amplifier 112 generates error signal EA from the difference between its inverting and non-inverting inputs, and PWM comparator 114 compares the error signal EA with ramp signal Vramp to determine the PWM signal for the driver 104 . From the equations EQ-1, EQ-2 and EQ-3, it is known that the output voltage Vo of the regulator 100 will decrease as the inductor current IL increases.
FIG. 2 schematically shows another conventional voltage regulator 200 with voltage droop function, which comprises control circuit 102 , driver 104 , transistors 106 and 108 , current sense circuit 110 , error amplifier 112 , PWM comparator 114 , and current sense resistor Rs as well. However, the reference voltage Vref is coupled to the non-inverting input of the error amplifier 112 via the droop resistor R ADJ and pin 116 , and the output of the current sense circuit 110 is coupled to the non-inverting input of the error amplifier 112 . When the current sense signal Ix passes through the droop resistor R ADJ , load line droop voltage Vdroop is produced as described in the equation EQ-2. The inverting input of the error amplifier 112 is coupled to the output Vo, and thereby the output voltage Vo follows the equation EQ-3 due to virtual ground. Consequently, according to the equations EQ-1, EQ-2 and EQ-3, it is known that the output voltage Vo of the regulator 200 will decrease as the inductor current IL increases.
In a voltage regulator with droop function, the load line droop signal proportional to the output current is sensed by the current sense resistor. Unfortunately, the resistance of an ordinary resistor is a function of temperature, so that the load line is also the function of temperature. Consequently, incorrect operations may happen because the control circuit 102 provides incorrect PWM signal due to the incorrect current sense signal Ix caused by the temperature coefficient of the current sense resistor Rs. In order to prevent mal-operations by the control circuit 102 resulted from temperature variations, the droop resistor R ADJ with proper negative temperature coefficient is chosen to be positioned in the vicinity of the current sense resistor Rs to compensate the voltage variations caused by temperature changes on the current sense resistor Rs with positive temperature coefficient. Nevertheless, resistors with negative temperature coefficients are not ordinary resistors and thereby are more expensive. In addition, in order to position the droop resistor R ADJ nearby the current sense resistor Rs, the conductive wire between the pin 116 and droop resistor R ADJ is lengthened, which makes the pin 116 tend to be affected by switching noises. Moreover, there is always a distance between the resistors R ADJ and Rs, and hence the temperature changes in the resistors R ADJ and Rs are different, thereby introducing inaccurate compensation to the current sense signal Ix. Furthermore, the position of the droop resistor R ADJ in one voltage regulator may be different from that in another, and thereby various resistors with different negative temperature coefficients have to be prepared for the droop resistor R ADJ in applications of various voltage regulators.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a temperature compensation device and method for a voltage regulator.
Another object of the present invention is to provide a temperature compensation device and method to cancel the temperature coefficient of the load line signal to zero, so as to obtain a temperature-invariant load line.
Yet another object of the present invention is to provide a temperature compensation device and method without lengthened conductive wire to avoid noise interferences.
Still another object of the present invention is to provide a temperature compensation device and method having tunable temperature coefficient for compensating variations caused by current sense resistor due to temperature changes.
In a voltage regulator including an inductor current flowing through a sense element with a first temperature coefficient, and a current sense circuit for generating a current sense signal related to the first temperature coefficient by sensing the inductor current from the sense element, according to the present invention, a temperature compensation device comprises a temperature coefficient tuner to determine a second temperature coefficient according to the first temperature coefficient and a temperature variation, and a compensation signal generator coupled to the temperature coefficient tuner to produce a compensation signal related to the second temperature coefficient to compensate the current sense signal. In one embodiment, the temperature coefficient tuner comprises a thermistor and temperature-invariant resistors to constitute an equivalent resistor with the second temperature coefficient, and the second temperature coefficient is determined by selecting the resistances of the temperature-invariant resistors. In one embodiment of the compensation signal generator, a current source supplies a temperature-invariant current to the temperature coefficient tuner to produce a voltage related to the second temperature coefficient, thereby further generating the compensation signal to compensate variations in the current sense signal caused by the first temperature coefficient.
BRIEF DESCRIPTION OF DRAWINGS
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings, in which:
FIG. 1 schematically shows a conventional voltage regulator with voltage droop function;
FIG. 2 schematically shows another conventional voltage regulator with voltage droop function;
FIG. 3 schematically shows a voltage regulator according to the present invention;
FIG. 4 shows another embodiment for the temperature coefficient tuner in FIG. 3 ;
FIG. 5 schematically shows another voltage regulator according to the present invention; and
FIG. 6 schematically shows a voltage regulator with configurable compensation temperature according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, FIG. 3 schematically shows a voltage regulator 300 , in which control circuit 302 comprises error amplifier 310 in response to the output voltage Vo of the regulator 300 and reference voltage Vref to produce error signal EA for PWM comparator 312 to compare with ramp signal Vramp to thereby generate PWM signal, and with the PWM signal driver 304 switches transistors 306 and 308 coupled in series between input voltage Vin and ground GND to produce inductor current IL flowing through inductor L to charge output capacitor Co to generate the output voltage Vo. According to the voltage drop across current sense resistor Rs that is coupled to the inductor L, transconductive amplifier 324 , serving as current sense circuit, generates current sense signal Ix 1 supplied to temperature compensation device 305 via sample-and-hold circuit 322 . Owing to the current sense resistor Rs having temperature coefficient TC 1 , the current sense signal Ix 1 will be affected by the temperature coefficient TC 1 . In order to eliminate the influence of the temperature coefficient TC 1 for the control circuit 302 to operate correctly, the temperature compensation device 305 will compensate the current sense signal Ix 1 so that current sense signal Ix 2 invariant to the temperature coefficient TC 1 is obtained to couple to resistor R ADJ to produce load line droop voltage Vdroop.
In the temperature compensation device 305 , temperature coefficient tuner 307 comprises thermistor RTSEN with fixed temperature coefficient, and variable resistors RTJ 1 and RTJ 2 that are temperature invariant. In this embodiment, the thermistor RTSEN is integrated in the chip of the driver 304 . Generally, a chip of the driver 304 has excess pins, and hence the pin count will not increase when the thermistor RTSEN is integrated in the chip of the driver 304 . In addition, the driver 304 is very close to the transistors 306 and 308 , which are dominant heat sources, to the inductor L, as well as to the current sense resistor Rs. Thereby, the difference between the temperature changes in the thermistor RTSEN and current sense resistor Rs is extremely small. Moreover, by integrating the thermistor RTSEN in the chip of the driver 304 , its resistance and temperature coefficient can be made more precisely by using various technologies in the manufacturing process. In the temperature coefficient tuner 307 , the combination of the thermistor RTSEN and resistors RTJ 1 and RTJ 2 constitutes an equivalent resistor with temperature coefficient TC 2 . Those skilled in the art of electronic circuits may know the temperature coefficient is
TC2 = d { RTJ1 × [ RTJ2 + R ( T2 ) ] RTJ1 + [ RTJ2 + R ( T2 ) ] } dT2 , [ EQ - 4 ]
where T 2 is the temperature of the thermistor RTSEN, and R(T 2 ) is the resistance of the thermistor RTSEN at temperature T 2 . In another embodiment, as the temperature coefficient tuner 330 shown in FIG. 4 , the variable resistor RTJ 1 is coupled in series to the parallel connection of the variable resistor RTJ 2 and thermistor RTSEN, and the temperature coefficient of this equivalent resistor is
TC2 = d [ RTJ1 + RTJ2 × R ( T2 ) RTJ2 + R ( T2 ) ] dT2 . [ EQ - 5 ]
From the equation EQ-4 or EQ-5, it is known that the temperature coefficient TC 2 of the equivalent resistor can be tuned by adjusting the resistances of the variable resistors RTJ 1 and RTJ 2 . One skilled in the art knows that in order to compensate voltage changes caused by the temperature coefficient TC 1 of the current sense resistor Rs, it should be satisfied that
TC 2×Δ T 2=Δ T 1× TC 1, [EQ-6]
where ΔT 1 is the temperature change on the current sense resistor Rs, and ΔT 2 is the temperature change on the thermistor RTSEN. According to the equation EQ-6, the temperature coefficient required for the equivalent resistor in the temperature coefficient tuner 307 can be derived as
TC2 = Δ T1 × TC1 Δ T2 . [ EQ - 7 ]
In the regard of current technology, it is not difficult to obtain the temperature changes on the current sense resistor Rs and the thermistor RTSEN. Referring to FIG. 3 , current source 316 in the compensation signal generator 309 supplies temperature-invariant current Iz to the temperature coefficient tuner 307 , and accordingly the equivalent resistor composed of the resistors RTSEN, RTJ 1 and RTJ 2 will produce the voltage drop
VTSEN=Iz×R TT ( TC 2), [EQ-8]
where R TT (TC 2 ) is the resistance of the equivalent resistor. By the equation EQ-8, it is shown that the voltage VTSEN is also dependent on the temperature coefficient TC 2 . The non-inverting input of buffer 320 is coupled with the voltage VTSEN, and according to virtual ground, the voltage on the inverting input of the buffer 320 is equal to the voltage VTSEN. Thereby, passing through temperature-invariant resistor RTC, the current serving as the compensation signal is
ITC = VTSEN RTC = Iz × R TT ( TC2 ) RTC . [ EQ - 9 ]
By the equation EQ-9, it is known that the current ITC is dependent on the temperature coefficient TC 2 . Operational circuit 314 divides the current sense signal Ix 1 by the current ITC to result in current sense signal Ix 2 to compensate the influence of the temperature coefficient TC 1 on the current sense signal Ix 1 .
In FIG. 3 , the temperature compensation device 305 makes use of the variable resistors RTJ 1 and RTJ 2 and the thermistor RTSEN to form an equivalent resistor, and tunes the temperature coefficient of the equivalent resistor by adjusting the resistance of the variable resistors RTJ 1 and RTJ 2 . Consequently, it is not necessary to prepare resistors with various temperature coefficients for various voltage regulator applications, and the temperature coefficient of the thermistor RTSEN can be positive. Thus, the cost can be reduced effectively without the need to use extraordinary resistors with negative temperature coefficients. Furthermore, it is not necessary for the resistor R ADJ in FIG. 3 to lengthen the conductive wire for arranging the resistor R ADJ close to the current sense resistor Rs as the conventional voltage regulator 200 shown in FIG. 2 . Hence, noise interference caused by lengthened conductive wire can be prevented.
In the temperature compensation device 305 , the current sense signal Ix 1 is divided by the current ITC to obtain the current sense signal Ix 2 in order to compensate the influence of the temperature coefficient TC 1 on the current sense signal Ix 1 . Nevertheless, the compensation function can also be achieved by applying other operational methods. As shown in FIG. 5 , likewise, voltage regulator 400 comprises control circuit 302 , driver 304 , transistors 306 and 308 , error amplifier 310 , PWM comparator 312 , transconductive amplifier 324 , and resistors Rs and R ADJ . In temperature compensation device 402 , likewise, current source 316 , transistor M, buffer 320 , and resistors RTSEN, RTJ 1 , RTJ 2 , and RTC are included. However, in this embodiment, the current sense signal Ix 1 is mirrored by mirror circuit 408 , and two identical current sense signals Ix 1 are produced accordingly, for providing for operational circuits 404 and 406 . The current sense signal Ix 1 supplied to the operational circuit 406 is multiplied by current ITC and divided by temperature-invariant reference current Iref to obtain current signal
I× 3 =I× 1 ×ITC÷Iref [EQ-10]
In the operational circuit 404 , the other current sense signal Ix 1 minus the signal Ix 3 to obtain the current sense signal Ix 2 for compensating variations on the current sense signal Ix 1 caused by the temperature coefficient TC 1 .
Moreover, the temperature compensation device according to the present invention can also be configured with threshold temperature for compensation. FIG. 6 shows voltage regulator 500 with configurable compensation temperature according to the present invention, which also comprises control circuit 302 , driver 304 , transistors 306 and 308 , error amplifier 310 , PWM comparator 312 , sample-and-hold circuit 322 , transconductive amplifier 324 , and resistors Rs and R ADJ . In temperature compensation device 502 , temperature coefficient tuner 307 also includes resistors RTSEN, RTJ 1 , and RTJ 2 to form an equivalent resistor with temperature coefficient TC 2 . Compensation signal generator 309 supplies current Iz provided by current source 316 to the temperature coefficient tuner 307 to produce voltage VTSEN, and temperature-invariant current Iz 1 provided by current source 504 to temperature-invariant resistor RTSET to produce threshold voltage VTSET. Analog summing circuit 506 has a positive input coupled with the voltage VTSEN and a negative input coupled with the threshold voltage VTSET. When the temperature of the thermistor RTSEN increases, the voltage VTSEN will increase as well. As the temperature of the thermistor RTSEN increases to a predetermined threshold, the voltage VTSEN will be greater or equal to the threshold voltage VTSET, such that the summing circuit 506 produces output
Vcomp=VTSEN−VTSET, [EQ-11]
to the non-inverting input of buffer 320 . Due to virtual ground, the voltage on the inverting input of the buffer 320 is equal to Vcomp, and thereby determining the current passing through resistor RTC for the compensation signal
ITC = V comp RTC . [ EQ - 12 ]
Operational circuit 314 receives the current ITC through transistor M, and divides the current sense signal Ix 1 by the current ITC to determine the current sense signal Ix 2 for compensating variations caused by the temperature coefficient TC 1 of the current sense resistor Rs.
In the foregoing embodiments, the resistor R ADJ is coupled between the current sense signal Ix 2 and reference voltage Vref. Alternatively, the resistor R ADJ can be coupled between the current sense signal Ix 2 and output Vo of the regulator, as the conventional regulator 100 shown in FIG. 1 does. In addition, although the method for sensing the inductor current IL in the foregoing embodiments is sensing the voltage drop across the current sense resistor Rs coupled in series to the inductor L, other methods, such as sensing the voltage drop across the parasitic resistor of the inductor L, sensing the voltage drop across the resistor coupled in series to the transistor 308 , and sensing the voltage drop across the transistor 308 , can also be adopted. Single-phase voltage regulator is used in the foregoing embodiments to illustrate the principles of the present invention. In multi-phase voltage regulators, the described principles in the foregoing single-phase voltage regulators can be applied to implement as well.
While the present invention has been described in conjunction with preferred embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and scope thereof as set forth in the appended claims. | In a voltage regulator including an inductor current flowing through a sense element with a first temperature coefficient, and a current sense circuit for generating a current sense signal related to the first temperature coefficient by sensing the inductor current from the sense element, a temperature compensation device and method determines a second temperature coefficient according to the first temperature coefficient and temperature variation, and produces a compensation signal with the second temperature coefficient to compensate variations in the current sense signal caused by the first temperature coefficient. | 8 |
DOMESTIC PRIORITY
[0001] This application is a continuation of and claims priority from U.S. patent application Ser. No. 15/248,002, filed on Aug. 26, 2016, entitled “PURE BORON FOR SILICIDE CONTACT,” which is a continuation of and claims priority from U.S. Pat. No. 9,484,431, issued on Nov. 1, 2016, entitled “PURE BORON FOR SILICIDE CONTACT,” each application is incorporated herein by reference in its entirety.
[0002] The present invention generally relates to metal-oxide-semiconductor field-effect transistors (MOSFET), and more specifically, to source/drain contact structures.
[0003] The MOSFET is a transistor used for amplifying or switching electronic signals. The MOSFET has a source, a drain, and a metal oxide gate electrode. The metal gate is electrically insulated from the main semiconductor n-channel or p-channel by a thin layer of insulating material, for example, silicon dioxide or glass, which makes the input resistance of the MOSFET relatively high. The gate voltage controls whether the path from drain to source is an open circuit (“off”) or a resistive path (“on”).
[0004] N-type field effect transistors (NFET) and p-type field effect transistors (PFET) are complementary MOSFETs. The NFET uses electrons as the majority current carriers and is built directly on a p-type substrate with n-doped source and drain junctions (also called epitaxial contacts) and an n-doped gate. The PFET uses holes as the majority current carriers and is built on an n-well with p-doped source and drain junctions (epitaxial contacts) and a p-doped gate. The dopant concentration in the source and drain junctions is an important parameter for optimal transistor function.
SUMMARY
[0005] In one embodiment of the present invention, a semiconductor device includes a gate disposed over a substrate; a source region and a drain region on opposing sides of the gate; and a pair of trench contacts over and abutting an interfacial layer portion of at least one of the source region and the drain region; wherein the interfacial layer includes boron in an amount in a range from about 5×10 21 to about 5×10 22 atoms/cm 2 .
[0006] In another embodiment, a method of making a semiconductor device includes performing an epitaxial growth process to form epitaxial contacts on opposing sides of a gate positioned over a substrate; removing portions of the epitaxial contacts to form trench contact patterns; depositing a conformal layer including amorphous boron within the trench contact patterns, the conformal layer forming a discrete interfacial layer within the epitaxial contacts, and the discrete interfacial layer including boron in an amount in a range from about 5×10 21 to about 5×10 22 atoms/cm 2 ; removing the conformal layer including amorphous boron; and filling the trench contact patterns with a high-k dielectric material and a conductive metal to form the trench contacts.
[0007] Yet, in another embodiment, a method of making a semiconductor device includes performing an epitaxial growth process to form epitaxial contacts on opposing sides of a gate positioned over a substrate; removing portions of the epitaxial contacts to form trench contact patterns; performing a deposition process to deposit a conformal layer including substantially pure amorphous boron within the trench contact patterns, the conformal layer forming a discrete interfacial layer within the epitaxial contacts comprising boron in an amount in a range from about 5×10 21 to about 5×10 22 atoms/cm 2 ; removing the conformal layer including amorphous boron; and filling the trench contact patterns with a high-k dielectric material and a conductive metal to form the trench contacts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The forgoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0009] FIGS. 1-7 illustrate an exemplary method of making a PFET source/drain contact according to embodiments the present invention, in which:
[0010] FIG. 1 is a cross-sectional side view of a semiconductor device with a PFET and a NFET formed over a substrate;
[0011] FIG. 2 is a cross-sectional side view after performing an etching process to form trench contacts over the source/drain regions;
[0012] FIG. 3 is a cross-sectional side view after lithographic patterning to block the NFET region;
[0013] FIG. 4A is a cross-sectional side view after depositing a conformal layer of amorphous boron;
[0014] FIG. 4B is a cross-sectional side view after removing the amorphous boron layer;
[0015] FIG. 4C is a cross-sectional side view after removing the lithographic patterning mask;
[0016] FIG. 5A is a cross-sectional side view after depositing a liner in the trench contacts;
[0017] FIG. 5B is a cross-sectional side view after filling the trench contact with a conductive metal;
[0018] FIG. 6A is a cross-sectional side view after depositing an oxide layer over the semiconductor device;
[0019] FIG. 6B is a cross-sectional side view after etching to form the gate contact patterns over the gates; and
[0020] FIG. 7 is a cross-sectional side view after depositing a gate contact liner and conductive gate material.
DETAILED DESCRIPTION
[0021] Although the dopant concentration (e.g., boron (B) concentration) can significantly improve functioning at the PFET source/drain contact, the ability to increase the dopant concentration by ion implantation or other methods (e.g., in-situ based doping) is limited to an upper limit of about 5×10 20 atoms/centimeter 2 (atoms/cm 2 ).
[0022] Accordingly, embodiments of the present invention provide a PFET source/drain contact with a high boron concentration in silicon (Si) or silicon germanium (SiGe), up to about 3×10 22 atoms/cm 2 . Further, the boron mixes with the Si or SiGe with to provide high activity in the contact because a high boron concentration provides decreased resistance. A method of making the PFET source/drain contact with a high boron concentration (e.g., 1×10 19 to about 1×10 21 atoms/cm 2 ) is now described in detail with accompanying figures. It is noted that like reference numerals refer to like elements across different embodiments.
[0023] The following definitions and abbreviations are to be used for the interpretation of the claims and the specification. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains” or “containing,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, a mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus.
[0024] As used herein, the articles “a” and “an” preceding an element or component are intended to be nonrestrictive regarding the number of instances (i.e. occurrences) of the element or component. Therefore, “a” or “an” should be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.
[0025] As used herein, the terms “invention” or “present invention” are non-limiting terms and not intended to refer to any single aspect of the particular invention but encompass all possible aspects as described in the specification and the claims.
[0026] As used herein, the term “about” modifying the quantity of an ingredient, component, or reactant of the invention employed refers to variation in the numerical quantity that can occur, for example, through typical measuring and liquid handling procedures used for making concentrates or solutions. Furthermore, variation can occur from inadvertent error in measuring procedures, differences in the manufacture, source, or purity of the ingredients employed to make the compositions or carry out the methods, and the like. In one aspect, the term “about” means within 10% of the reported numerical value. In another aspect, the term “about” means within 5% of the reported numerical value. Yet, in another aspect, the term “about” means within 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1% of the reported numerical value.
[0027] Turning now to the Figures, FIGS. 1-7 illustrate an exemplary method of making a PFET source/drain contact according to embodiments of present invention. FIG. 1 is a cross-sectional side view of a semiconductor device with a NFET 150 and a PFET 151 formed over a common substrate 101 . Non-limiting examples of suitable substrate materials include silicon, silicon dioxide, aluminum oxide, sapphire, germanium, gallium arsenide (GaAs), an alloy of silicon and germanium, indium phosphide (InP), or any combination thereof. Other examples of suitable substrates 101 include silicon-on-insulator (SOI) substrates with buried oxide (BOX) layers. The thickness of the substrate 101 is not intended to be limited. In one aspect, the thickness of the substrate 101 is in a range from about 2 mm to about 6 mm for bulk semiconductor substrates. In another aspect, the thickness of the substrate 101 is in a range from about 25 nm to about 50 nm for the silicon layer in SOI substrates
[0028] To form the epitaxial contacts forming the source regions 120 and 122 and the drain region 121 and 123 , lithography and etching are performed. Lithography can include depositing a photoresist (not shown) onto the substrate 101 and developing the exposed photoresist with a resist developer to provide a patterned photoresist. The epitaxial contacts are formed by performing an epitaxial growth process to deposit a doped material (e.g., silicon). The type of dopant used depends on whether the MOSFET is the NFET 150 or the PFET 151 . Non-limiting examples of suitable dopants for the NFET 150 include n-type dopants (e.g., Group V elements such as phosphorus). Non-limiting examples of suitable dopants for the PFET 151 include p-type dopants (e.g., Group III such as boron). Generally, the concentration of dopant in the epitaxial contacts is in a range from about 1×10 19 to about 1×10 21 atoms/cm 2 .
[0029] The thickness of the epitaxial contacts forming the source regions 120 and 122 and the drain regions 121 and 123 is not intended to be limited. In one aspect, the thickness of the epitaxial contacts is in a range from about 5 nm to about 60 nm. In another aspect, the thickness of the epitaxial contacts is in a range from about 5 nm to about 10 nm.
[0030] The gates 110 and 112 are formed by lithographic patterning and etching. Initially, a “dummy gate” is formed by filling the gate region with a suitable removable gate material, for example, amorphous silicon (polysilicon). The removable gate material is subsequently removed, and the gates 110 and 112 are filled with a conductive gate material. A high-k dielectric liner can be deposited before filling with the conductive gate material.
[0031] The high-k dielectric material can be a dielectric material having a dielectric constant greater than 4.0, 7.0, or 10.0. Non-limiting examples of suitable materials for the high-k dielectric material include oxides, nitrides, oxynitrides, silicates (e.g., metal silicates), aluminates, titanates, nitrides, or any combination thereof. Other non-limiting examples of suitable high-k dielectric materials include HfO 2 , ZrO 2 , Al 2 O 3 , TiO 2 , La 2 O 3 , SrTiO 3 , LaAlO 3 , Y 2 O 3 , a pervoskite oxide, or any combination thereof. The high-k dielectric material layer may be formed by known deposition processes, for example, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), evaporation, physical vapor deposition (PVD), chemical solution deposition, or other like processes. The thickness of the high-k dielectric material may vary depending on the deposition process as well as the composition and number of high-k dielectric materials used. The high-k dielectric material layer may have a thickness in a range from about 0.5 to about 20 nm.
[0032] Non-limiting examples of suitable conductive gate metals include aluminum (Al), platinum (Pt), silver (Au), tungsten (W), titanium (Ti), or any combination thereof. The conductive metal may be deposited by a known deposition process, for example, CVD, PECVD, PVD, plating, thermal or e-beam evaporation, and sputtering.
[0033] The thickness of the gates 110 and 112 is not intended to be limited. In one aspect, the thickness of the gates 110 and 112 is in a range from about 20 nm to about 75 nm. In another aspect, the thickness of the gates 110 and 112 is in a range from about 20 nm to about 50 nm.
[0034] A blanket oxide layer 130 is deposited onto both NFET 150 and PFET 151 regions over the substrate 101 . Non-limiting examples of suitable materials for the oxide layer 130 include flowable oxides (e.g., liquid solutions of hydrogen silsesquioxane in a carrier solvent) and silicon dioxide. The thickness of the oxide layer 130 is not intended to be limited. In one aspect, the thickness of the oxide layer 130 is in a range from about 50 nm to about 150 nm. In another aspect, the thickness of the oxide layer 130 is in a range from about 60 nm to about 115 nm.
[0035] An optional silicon nitride (SiN) layer 140 is deposited onto the oxide layer 130 . The thickness of the SiN layer 140 is not intended to be limited. In one aspect, the thickness of the SiN layer 140 is in a range from about 5 nm to about 20 nm. In another aspect, the thickness of the SiN layer 140 is in a range from about 10 nm to about 15 nm.
[0036] FIG. 2 is a cross-sectional side view after performing an etching process to form trench contacts 201 over the source regions 120 and 122 and drain regions 121 and 123 . The etching process may be a dry etching process, for example, reactive ion etching (RIE). The etching process is performed through the SiN layer 140 , the oxide layer 130 , and a portion of the epitaxial contacts of the source regions 120 and 122 and drain regions 121 and 123 . The etching process removes a portion of and stops within a region of the epitaxial contacts to form a recess. The open trench contacts 201 form a trench contact pattern. The trench contact patterns have side walls (y) and a base (x) that protrude into the epitaxial contacts of the source region 122 and the drain region 123 .
[0037] FIG. 3 is a cross-sectional side view after lithographic patterning to block the NFET 150 region. A hard mask layer 301 is deposited over the NFET 150 portion of the substrate 110 . The hard mask layer 301 may include, for example, amorphous carbon (a-C), silicon nitride (SiN), or silicon dioxide (SiO 2 ). The hard mask layer 301 fills the open regions of the trench contacts 201 .
[0038] FIG. 4A is a cross-sectional side view after depositing a conformal layer of amorphous boron. The amorphous boron layer 401 is formed by using a deposition process (e.g., CVP or ALD) to deposit a conformal layer of amorphous boron within the trench contacts 201 over the PFET 151 . The amorphous boron layer 401 includes substantially pure boron. In one embodiment, the amorphous boron layer 401 includes 100 atomic % (at. %) boron. In another embodiment, the amorphous boron layer 401 includes at least 99 at. % boron. Yet, in another embodiment, the amorphous boron layer 401 includes at least 98 at. % boron.
[0039] Deposition of the amorphous boron layer 401 may be performed by Chemical Vapor Deposition (CVD). The conditions of the CVD process may be tailored to the particular semiconductor device. The CVD process may be performed at atmospheric pressure (i.e., about 760 Torr), or reduced pressures, for example 60 Torr or 36 Torr. In one exemplary embodiment, the deposition is performed at processing temperatures ranging from about 500° C. to about 800° C. Diborane (B 2 H 6 ) is injected into the reactor chamber as the dopant gas at a flow rate of, for example, 490 standard cubic centimeters per minute (sccm). Hydrogen gas (H 2 ) may be used as the carrier gas and for dilution of the doping source.
[0040] The hard mask layer 301 protects the trench contacts 201 over the NFET 150 region. The amorphous boron layer 401 lines the trench contacts 201 of the PFET 151 and forms an interfacial layer 410 including a high boron concentration in the epitaxial contacts of the source region 122 and drain region 123 . The interfacial layer 410 naturally forms in the source region 122 and drain region 123 upon disposing amorphous boron layer 401 within the trench contacts 201 .
[0041] In one aspect, the interfacial layer 410 has a thickness in a range from about 0.5 nm to about 2 nm. In another aspect, the interfacial layer 410 has a thickness in a range from about 1 nm to about 1.5 nm. Yet, in another aspect, the interfacial layer 410 has a thickness about or in any range from about 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1., 1.2, 1.3, 1.4, and 1.5 nm.
[0042] In one aspect, the interfacial layer 410 has a boron concentration in a range from about 5×10 21 to about 5×10 22 atoms/cm 2 . In another aspect, the interfacial layer 410 has a boron concentration in a range from about 1×10 22 to about 3×10 22 atoms/cm 2 .
[0043] FIG. 4B is a cross-sectional side view after removing the amorphous boron layer 401 . The amorphous boron layer 401 may be removed using any suitable process. Although the amorphous boron layer 401 is stripped, the interfacial layer 410 remains over the source region 122 and the drain region 123 . In one non-limiting example, a boiling solution of concentrated nitric acid (HNO 3 ) is used to remove the amorphous boron layer 401 . The temperature of the HNO 3 can be, for example, 110° Celsius (° C.). The concentration of the HNO 3 can be, for example, between about 50 and about 85%. In another non-limiting example, an aqua regia process can be used to remove the amorphous boron layer 401 . An aqua regia process involves using a nitro-hydrochloric acid (HCl) to etch away the amorphous boron layer 401 . The nitro-HCl mixture is formed by mixing concentrated nitric acid and hydrochloric acid in a volume ratio of, for example, 1:3.
[0044] FIG. 4C is a cross-sectional side view after removing the hard mask layer 301 over the NFET 150 region. The hard mask layer 301 can be removed by a wet cleaning process using, for example, HF or HCl and dry etching. Suitable dry etching processes include RIE, plasma etching, ion beam etching, laser ablation, or any combination thereof.
[0045] FIG. 5A is a cross-sectional side view after depositing a liner 501 in the trench contacts 201 . To form the liner 501 , a high-k dielectric material is deposited into the trench contacts. The high-k dielectric material can be a dielectric material having a dielectric constant greater than 4.0, 7.0, or 10.0. Non-limiting examples of suitable materials for the high-k dielectric material include oxides, nitrides, oxynitrides, silicates (e.g., metal silicates), aluminates, titanates, nitrides, or any combination thereof. Other non-limiting examples of suitable high-k dielectric materials include HfO 2 , ZrO 2 , Al 2 O 3 , TiO 2 , La 2 O 3 , SrTiO 3 , LaAlO 3 , Y 2 O 3 , a pervoskite oxide, or any combination thereof. The high-k dielectric material layer may be formed by known deposition processes, for example, CVD, PECVD, ALD, evaporation, PVD, chemical solution deposition, or other like processes. The thickness of the high-k dielectric material may vary depending on the deposition process as well as the composition and number of high-k dielectric materials used.
[0046] In one embodiment, the liner 501 includes a bilayer of Ti and TiN. The TiN is deposited over the layer of Ti to form the Ti/TiN liner. The thickness of the liner 501 can generally vary and is not intended to be limited. In one aspect, the thickness of the liner 501 is in a range from about 3 nm to about 10 nm. In another aspect, the thickness of the liner 501 is in a range from about 4 nm to about 9 nm.
[0047] FIG. 5B is a cross-sectional side view after filling the trench contacts 201 with a conductive metal 501 . Non-limiting examples of suitable conductive metals include tungsten, aluminum, platinum, gold, or any combination thereof. A planarization process, for example chemical mechanical planarization (CMP), is performed over the conductive metal 501 . The conductive metal may be deposited by a known deposition process, for example, CVD, PECVD, PVD, plating, thermal or e-beam evaporation, and sputtering.
[0048] FIG. 6A is a cross-sectional side view after depositing a blanket oxide layer 601 over the NFET 150 and PFET 151 regions of the semiconductor device. The oxide layer 601 can include, for example, tetraethyl-ortho-silicate (TEOS) or silicon dioxide.
[0049] FIG. 6B is a cross-sectional side view after etching to form the gate contact patterns 610 over the gates 110 and 112 . In one non-limiting example, a RIE process is performed to form the gate contact patterns 610 .
[0050] FIG. 7 is a cross-sectional side view after depositing a gate contact liner 701 and conductive gate material 702 into the gate contact patterns 610 . The gate contact liner 701 can include, for example, a high-k dielectric material as described above for liner 501 (see FIG. 5A ). The conductive gate material 702 can be any of the conductive metal materials described above for the trench contacts 201 (see FIG. 5B ). A planarization process, for example, a CMP process, is performed over the conductive gate material 702 .
[0051] The above described embodiments of semiconductor devices and methods of making such devices provide various advantages. The methods provide a PFET source/drain contact with a high boron concentration in Si or SiGe, up to about 3−5×10 22 atoms/cm 2 . After depositing a layer of amorphous boron over the source and drain a contact, the boron mixes with the Si or SiGe with to provide high activity in the contact.
[0052] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, 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, element components, and/or groups thereof.
[0053] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
[0054] The flow diagrams depicted herein are just one example. There may be many variations to this diagram or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
[0055] The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein. | A semiconductor device includes a gate disposed over a substrate; a source region and a drain region on opposing sides of the gate; and a pair of trench contacts over and abutting an interfacial layer portion of at least one of the source region and the drain region; wherein the interfacial layer includes boron in an amount in a range from about 5×10 21 to about 5×10 22 atoms/cm 2 . | 7 |
FIELD OF THE INVENTION
[0001] The invention is directed to packet data networks, particularly to routing data packets in networks having routers configured as a virtual router using virtual router redundancy protocol (VRRP).
BACKGROUND OF THE INVENTION
[0002] VRRP is a protocol described in Internet Engineering Task Force (IETF) document RFC 3768. The purpose of VRRP is to increase the availability of a default gateway servicing hosts on the same subnet. VRRP allows two or more physical routers to act as a single virtual router comprising a primary router actively routing data packet traffic and one or more backup routers, one of which will replace the role of the primary router should it fail. Currently, there is a need to update VRRP for use with Internet Protocol version 6 (IPv6). For example, IETF draft-ietf-vrrp-unified-spec proposes such an updated version of VRRP.
[0003] VRRP is typically used by Enterprises to provide redundancy at some major strategic data center that requires continuous operation to serve its clients. In many cases, Enterprises build their data centers with two different backbone connections, each connection via a separate physical router. When implementing VRRP, the Enterprise will configure the two physical routers as a virtual router. Each of the physical routers will therefore have a respective connection to the backbone network and each will be connected to the data center's local area network (LAN), also referred to as a VRRP subnet subsequent to VRRP implementation. The VRRP subnet provides a connection between the two physical routers, hereinafter referred to as VRRP routers.
[0004] According to routing protocols such as border gateway protocol (BGP) described in IETF document RFC4271, a route metric/cost is associated with the output side of each router interface. This cost is configurable by the system administrator and it always has a default value. The lower the cost, the more likely the interface is to be used to forward data traffic.
[0005] By design, VRRP and routing protocols do not interact with each other. This means that a routing protocol will be unaware of the state of a VRRP router interface, also referred to herein as a VRRP interface. That is, the routing protocol will be unaware whether the VRRP router is a primary or a backup VRRP router. When advertising a Local Interface route of the VRRP subnet, from both the primary and backup routers, the same default cost is used.
[0006] The problem is that the static route metric/cost can result in routes to the VRRP subnet having equal cost, or in many configurations the backup VRRP router ends up being the best next hop to the VRRP subnet. While neither case is desirable, the former can be particularly problematic for applications sensitive to unequal multipath delays if equal cost multipath (ECMP) routing is enabled, since traffic from a remote host to any host in the VRRP subnet can take different paths. IETF documents RFC2991 and RFC2992 address issues and techniques of ECMP routing.
SUMMARY
[0007] Embodiments of the invention are directed to adjusting route metrics to aid in providing predictable selection of routes into VRRP subnets.
[0008] According to an embodiment of the invention, a simple mechanism is provided to influence routing protocols depending on the state of a VRRP interface without having to modify the routing protocols or VRRP standards.
[0009] Some embodiments of the invention enable a user to activate VRRP routing on a router, after which a routing table metric of the router will be updated depending on whether the router is a primary or a backup VRRP router.
[0010] Advantageously, providing predictable selection of routes into VRRP subnets enhances a network operator's ability to meet service level agreements (SLA) for critical or delay sensitive applications.
[0011] According to an aspect of the invention a method is provided of adjusting route metrics in a data packet router. The method comprises the steps of: determining if virtual routing redundancy protocol VRRP routing is enabled on the router; determining, responsive to VRRP being enabled on the router, if the router is a backup VRRP router; and setting on the router, responsive to VRRP being enabled on the router and the router being a VRRP backup router, a pointer in a routing information base RIB entry for an interface of the router to point to a first metric entry of a management information base MIB object corresponding to the interface.
[0012] Advantageously, the method may further include the step of setting on the router, responsive to VRRP being enabled on the router and the router not being a VRRP backup router, the pointer to point to a second metric entry of the MIB object, wherein the second metric entry has a value that is different than a value of the first metric entry.
[0013] Advantageously, the method may further include the step of setting on the router, responsive to VRRP not being enabled on the router, the pointer to point to the second metric entry of the MIB object.
[0014] According to an aspect of the invention data packet router capable of executing virtual routing redundancy protocol VRRP is provided. The router comprises a routing information base RIB having an entry including a pointer; a management information base MIB having an object corresponding to an interface of the router; a VRRP flag for providing an indication whether or not VRRP routing is enabled on the router; a virtual router identifier VRID for indicating whether or not the router is a backup VRRP router when VRRP routing is enabled on the router; and a function for causing the pointer to point to a first metric of the object when VRRP routing is enabled on the router and the router is a backup VRRP router and for causing the pointer to otherwise point to a second metric of the object.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiments, as illustrated in the appended drawings, where:
[0016] FIG. 1 illustrates a VRRP configuration resulting in ECMP route selection;
[0017] FIG. 2 illustrates paths taken by data packet traffic in FIG. 1 ;
[0018] FIG. 3 illustrates a VRRP configuration according to an embodiment of the invention; and
[0019] FIG. 4 illustrates a method of adjusting route metrics in the VRRP configuration of FIG. 3 .
[0020] In the figures like features are denoted by like reference characters.
DETAILED DESCRIPTION
[0021] In reference to FIG. 1 , a VRRP configuration 100 includes a first host 102 connected to a VRRP subnet 104 , also referred to as subnet 1 . A second host 106 can communicate data packets with the first host 102 via a virtual router 107 , comprising a first router 108 and a second router 110 , and a third router 112 . The first router 108 is the primary router of the virtual router 107 , so denoted by having a VRID set to “primary” in the figure, whereas the second router 110 is the backup router of the virtual router 107 , so denoted by its VRID set to “secondary” in the figure. The virtual router 107 has two connections to the third router 112 , these connections representing the aforementioned connections to a backbone network. A first backbone connection 114 of the two connections enables the first router 108 to communicate data packets with the third router 112 , and a second backbone connection 115 likewise enables the second router 110 to communicate data packets to the third router 112 . Each of the first and second routers 108 , 110 also has a respective connection to the VRRP subnet 104 . Respectively these connections are a first LAN connection 116 and a second LAN connection 117 .
[0022] The third router 112 includes a routing table 118 that among other entries includes routing information to route data packets to the VRRP subnet 104 . A first entry 120 of the table 118 for a first route includes a network parameter equal to the address of the VRRP subnet, shown as “Subnet 1 ” in the figure, a next hop parameter equal to the address of the first router 108 , shown as “Router 1 ” in the figure, and a metric parameter for the first route, shown as “1” in the figure. Likewise, a second entry 122 of the table 118 for a second route includes a network parameter equal to the address of the VRRP subnet, shown as “Subnet 1 ” in the figure, a next hop parameter equal to the address of the second router 110 , shown as “Router 2 ” in the figure, and a metric parameter for the second route, shown as “1” in the figure. In the case where ECMP route selection is employed by the third router 112 , the first and second routes would be equally likely to be selected by the router 112 since the values of their respective metric parameters are equal in the routing table 118 . In other words, the third router 112 has two equal cost multipath routes to the VRRP subnet 104 .
[0023] In reference to FIG. 2 , a flow of data packets between the first host 102 and the second host 106 follows a first path 202 through the VRRP subnet 104 , the first router 108 , and the third router 112 . The first path 202 is not problematic because the first router 108 in this case is the primary router of the virtual router 107 . However, when ECMP is employed by the third router 112 , data packets flowing from the second host 106 to the first host 102 can take one of two paths; either through the first router 108 via a second path 204 or through the second router 110 via a third path 206 . This situation can be problematic for delay sensitive traffic if the second and third paths 204 , 206 have unequal transit delays.
[0024] In some cases where ECMP path selection uses a hashing algorithm based on the destination IP address of the subject data packet, the same path could be selected for all data packets destined to that IP address. In such cases it is possible that the selected path could transit the backup router of the virtual router, which would be undesirable since the traffic should be routed through the primary router of that virtual router. Some ECMP hashing algorithms could even be more dynamic as they might consider other variables such as source and/or destination TCP/UDP ports or even random generated keys, which would make predicting the selected path even more difficult, such as could be required to ensure SLAs are met on applications that are sensitive to traffic delays.
[0025] With reference to FIG. 3 , a VRRP configuration 300 according to an embodiment of the invention enables path selection at the third router 112 to be influenced depending on which of the first or second routers 108 , 110 of the virtual router 107 is the primary router and without having to modify VRRP or other routing protocols running on the routers.
[0026] To that end, modifications 301 have been made to the second router 110 . The modifications affect a routing information base (RIB) 302 , which includes an entry 304 of a metric for an interface to the subnet 1 (the VRRP subnet 104 ). The entry 304 sets the value of the metric as determined by a pointer, shown as “PTR” in the figure. The modifications 301 also affect a management information base (MIB) 306 having a first metric entry 310 and a second metric entry 312 for an IP route entry object 308 associated with the subnet 1 . The first metric entry 310 , shown as “IProuteMetric 1 ” in the figure has a default value and the second metric entry 312 , shown as “IProuteMetric 2 ” in the figure, has a value equal to the sum of the default value plus an offset shown as “D” in the figure. The value of the offset D can be entered by an operator using a network management system 314 connected to the VRRP subnet 104 , for example. The modifications 301 include addition of a pointer function 318 that uses a VRRP flag 316 and the state of the router's VRID, i.e. either set to “primary” or “backup”, to determine which one of the first or second metric entries 310 , 312 is referenced by the pointer (PTR) of the RIB 302 . The value of the VRRP flag 316 is set to reflect whether VRRP is enabled on the router 110 or not. For example, the VRRP flag 316 could be set by an operator using the NMS 314 .
[0027] The first router 108 has been modified in the same manner as the second router 110 was modified by the modifications 301 . Consequently, both the first and second routers 108 , 110 will have respective metrics for an interface to subnet 1 , wherein the value of each metric will be dependent on whether the given router 108 , 110 has VRRP enabled and, if so, whether that router is the primary router or a backup router of the virtual router 107 . Additionally, the first and second routers 108 , 110 will include the value of their respective metric in route advertisements to other routers such as the third router 112 , in accordance with routing protocols running on those routers. The result of receiving such route advertisements is shown in the routing table 118 of the third router 112 , wherein the first entry 120 has a metric with a value of one and the second entry 122 has a metric with a different value, that value being “1+D”.
[0028] Since the first entry 120 has a metric with a lower value than that of the second entry, the third router 112 will now exclusively select the path (second path 204 of FIG. 2 ) associated with the first entry 120 for data packet traffic destined to the VRRP subnet 1 104 , e.g. the first host 102 . This is desirable because that path is via the first router 108 , which is the primary router of the virtual router 107 . However, if the second router 110 were to become the primary router, the first and second entries 120 , 122 would change due to new route advertisements from the first and second routers 108 , 110 such that the offset D would be included in the metric of the first entry 120 and not in that of the second entry 122 . In that case, the third router 112 would exclusively select the path (third path 206 of FIG. 2 ) associated with the second entry 122 for data packet traffic destined to the VRRP subnet 1 104 , e.g. the first host 102 .
[0029] To sum up, embodiments of the invention enable a user to activate VRRP routing on a router, via a network management system (NMS) console running command language interface (CLI) and simple network management protocol (SNMP). Accordingly, after VRRP routing has been activated, a routing table metric of the router will be updated depending on whether the router is a primary or a backup VRRP router. In the case the router has the VRRP virtual router interface as backup (i.e. VRID=backup), the router should take the regular metric of that interface and add a value “D”, which has the affect of decreasing the “priority” of routes involving that interface when they are advertized by any routing protocol running on the router. When the router becomes the primary VRRP router, it should re-establish the default metric on that interface. The value D is configurable, for example from a user interface of the router or via a NMS or other type of management system.
[0030] Advantageously, this technique can be applied on subnets where critical or delay sensitive applications reside, at the discretion of a network administrator, and on a per virtual router basis.
[0031] Embodiments of the invention provide a VRRP backup router with functionality to modify respective cost values of directly connected routes (local routes) and store each such value in one of the unused metrics of the IpRouteEntry object of the corresponding route. This object is part of MIB-II, which is the second version of the Management Information Base for use with network management protocols in TCP/IP-based internets and is defined in IETF document RFC1213. A configuration command is used to set the offset value D (desired degraded metric value), which is added to the default metric value for a given route to obtain a backup local metric. The backup local metric is stored in one of the unused metrics of the IpRouteEntry object of that route. The aforementioned pointer function 318 controls which metric value, i.e. the backup local metric or default metric, will be used in the RIB of the router. This value has local significance and it will not be managed or propagated by VRRP. Consequently, changes to any of the standard MIBs or objects of the VRRP protocols are not required.
[0032] The metrics of the IpRouteEntry object of MIB-II are shown in bold typeface:
[0000]
IpRouteEntry ::=
SEQUENCE {
ipRouteDest
IpAddress,
ipRouteIfIndex
INTEGER,
ipRouteMetric1
INTEGER,
ipRouteMetric2
INTEGER,
ipRouteMetric3
INTEGER,
ipRouteMetric4
INTEGER,
ipRouteNextHop
IpAddress,
ipRouteType
INTEGER,
ipRouteProto
INTEGER,
ipRouteAge
INTEGER,
ipRouteMask
IpAddress,
ipRouteMetric5
INTEGER,
ipRouteInfo
OBJECT IDENTIFIER
}.
[0033] Usually router vendors store the interface cost on ipRouteMetric 1 . A first embodiment of the invention stores the new backup local metric on the object ipRouteMetric 2 such that the pointer (PTR in FIG. 3 ) moves between ipRouteMetric 1 and ipRouteMetric 2 depending on the role of the VRRP router interface. The primary router 108 will point to ipRouterMetric 1 and backup router 110 will point to ipRouterMetric 2 . Other embodiments could use any other unused metric or mechanism to achieve the functionality described above.
[0034] In operation, embodiments of the invention achieve a “dynamic” metric. This results from adding the cost of the “default metric or configured metric” to a “desired degraded” metric value (the offset D) configurable by the network administrator. The resulting metric is used when the corresponding VRRP interface runs in backup state. When the VRRP interface runs in the primary state, i.e. the router becomes the primary router, then the value of the metric is reset back to the “default or configured metric”. In this manner the metric is dynamic. When network routing protocols import or redistribute the local routes, they will inherit the latest value of the “dynamic” metric. An example of such inheritance is shown in the routing table 118 of FIG. 3 .
[0035] Accordingly, network routing tables will include metrics that are effectively modified by the state of the VRRP routers, particularly the MIB object IpRouteEntry metrics of corresponding routes to those routers. The metrics of the routes will be dynamically modified by an amount, the offset D configured by the network administrator, when the VRRP interface of that route changes from a primary to a backup state and visa versa. Therefore, with the value of the offset D chosen with sufficient consideration to design of the network, all data packet traffic between local hosts, e.g. the first host 102 , and remotes hosts, e.g. the second host 104 , will be routed through the primary VRRP router 108 . Therefore packets transmitted or received from either of the local or remote hosts will take the same path, which solves the aforementioned problems for delay sensitive traffic.
[0036] FIG. 4 shows a method 400 of adjusting route metrics according to an embodiment of the invention. This method 400 is implemented in the pointer function 318 of FIG. 3 in both of the routers 108 , 110 .
[0037] Referring to FIG. 3 and FIG. 4 , immediately upon starting 402 the method 400 determines 404 if the VRRP routing is enabled on the router wherein the method 400 is implemented. This determination is made by checking the VRRP flag 316 . If the VRRP flag 316 is set, which means that VRRP routing is enabled, the method 400 then proceeds to determine 406 whether or not the router is currently acting as the backup VRRP router. This determination is made by checking the VRID of the router, which if set to “backup” (or some similar indication) means that the router is currently the backup VRRP router. If the router is currently the backup VRRP router, then the method 400 sets 408 the MIB pointer (PTR) of the RIB entry 304 for the interface of the VRRP subnet 104 to point to the second metric entry 312 of the corresponding MIB object 308 , which second metric entry 312 includes the offset D plus a default value. The method 400 then ends 412 .
[0038] However, if the method 400 determines 406 that the router is not currently the backup router, hence the router is currently the primary router, then the method 400 sets 410 the MIB pointer (FIR) of the RIB entry 304 for the interface of the VRRP subnet 104 to point to the first metric entry 310 of the corresponding MIB object 308 , which first metric entry 310 does not include the offset D but only includes the default value. The method 400 then ends 412 .
[0039] Likewise, if the method 400 determines 404 that VRRP routing is not enabled on the router, i.e. the VRRP flag 316 is not set, the method 400 sets 410 MIB pointer (PTR) of the RIB entry 304 for the interface of the VRRP subnet 104 to point to the first metric entry 310 . The method 400 then ends 412 .
[0040] The method 400 can be implemented to run in an endless loop so that any changes to enablement of VRRP routing on the router, e.g. the VRRP flag 316 , or the VRRP interface status, e.g. as indicated by the VRID either primary or backup, can be effected in the router's RIB with minimal delay. Alternatively, the start 402 of the method 400 could be initiated subsequent to detecting a change in the enablement of VRRP routing on the router or the status of the router's VRRP interface.
[0041] Advantageously, embodiments of the invention enable a network administrator to engineer traffic to follow the VRRP primary router location to obtain predictable routing paths that guarantee desirable SLAs for critical or time sensitive applications such as Voice over IP (VoIP). In VRRP enabled networks, embodiments of the invention provide a solution to dictate predictable paths in and out the VRRP network in presence of equal cost routing.
[0042] Numerous modifications, variations and adaptations may be made to the embodiments of the invention described above without departing from the scope of the invention, which is defined in the claims. | The invention is directed to routing data packets in networks having routers configured as a virtual router using virtual router redundancy protocol (VRRP). Embodiments of the invention adjust route metrics to aid in providing predictable selection of routes into VRRP subnets. Advantageously, providing predictable selection of routes into VRRP subnets enhances a network operator's ability to meet service level agreements for critical or delay sensitive applications. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to industrial fabrics such as conveying fabrics used in papermaking. More particularly, it relates to the combination of an endless woven fabric and an open flat fabric to form a laminated multilayer fabric which can be used, for example, as a base fabric for a wet press felt.
2. Description of the Prior Art
Papermakers fabrics are used to form, transport, dewater and dry paper on a papermaking machine. Papermakers press felts are designed to transport an aqueous web of paper through the press rollers of a papermaking machine and to assist in the dewatering of the paper web. Commonly, a papermakers wet press felt is constructed from a woven base fabric having fibrous batt material needled to one or both sides.
The amount of void volume within the base fabric of a press felt is directly related to the amount of water which can be handled internally by the felt as it conveys the paper web through press nips. Felts which can be run without water puddling behind the nip are less likely to result in crushing or damage to the aqueous web. In some cases, multilayered base fabrics are provided to enhance the void volume of the press felts. Papermakers fabrics may be made by endless weaving without a seam. In such cases, when a fabric is installed, the operating machinery has to be partially dismantled so that the fabric can be slipped onto the machine from the side. This is a slow and cumbersome method of installation since endless wet felts are relatively heavy and stiff and are commonly several meters wide and over 30 meters long. Moreover, not all papermaking equipment is designed to permit installation of non-seamed fabrics.
To simplify installation, press fabrics having seams have gained acceptance. It is easier to thread a flat, open-ended fabric through a papermaking machine and then join the fabric's opposing ends together in a seam on the machine, than it is to perform the cumbersome task of installing a non-seamed fabric.
A variety of seams and seaming methods are known in the art. Flat woven fabrics have been constructed with an independent seam structure attached to the ends of the fabric, such as by sewing a woven tape onto the fabric or utilizing clipper hooks. Additionally, papermaking fabrics are commonly formed with loops of yarn projecting from the fabric ends, the loops from both ends of the fabric are intermeshed and joined together by inserting a pintle wire or pin through the intermeshed end loops to secure the ends together. Other conventional fabric seams have also included the use of separately attached loop materials such as helical coils, spiral wires or metal clips. Various prior art seams are disclosed in U.S. Pat. Nos. 3,815,645; 4,824,525, 4,865,083; 5,053,109 and 5,117,865 which illustrate seams for woven fabrics constructed using either flat or endless weaving techniques.
It is desirable to provide a laminated multilayer fabric which provides good void volume and combines the ease of installation of a flat woven fabric while maintaining some of the fabric characteristics of an endless woven fabric.
SUMMARY OF THE INVENTION
The present invention is directed to a laminated multilayer industrial conveying fabric which is constructed by combining an endless fabric with an open flat fabric. The flat fabric is disposed within the interior of the endless fabric which is collapsed to define a flat sandwiched laminated construction. Accordingly, the laminated multilayer fabric includes top and bottom laminate layers defined by portions of the endless fabric and an intermediate laminate layer defined by the flat fabric. Each laminate layer may in turn include one or more woven layers dependent upon the weave structure selected for the endless and open flat fabrics which are used in the construction of the composite laminated fabric. Although the two component fabrics are preferably woven fabrics, non-woven fabrics, such as fabrics formed of spiral yarns linked together, may also be used.
The ends of the flat fabric include interconnecting means such as seaming loops. The flat fabric has a predetermined length determined by the size of the endless fabric such that the seaming loops or other interconnecting means project through the endless fabric at opposing ends of the laminated multilayer fabric. In use, the laminated multilayer fabric is threaded through the serpentine path of the conveying apparatus, such as a papermaking machine, and the opposing ends are seamed together by joining the projecting ends of the interior flat fabric.
The laminated fabric design has utility as an industrial conveying fabric where a relatively high caliper or multilayer fabric is desired such as for press felts and corrugator belts. Preferably, the laminated fabric is employed as a base fabric for a wet press felt. In finishing such a press felt, batting material may be needled on to one or both sides of the multilayer base fabric structure. A method for constructing the laminated fabric is also disclosed.
An object of the present invention is to provide a laminated multilayer fabric for papermaking and other industrial uses. It is also an object to provide such a fabric in which a pin seam may be formed quickly and economically in a fabric that is engineered to have desirable characteristics.
Other objects and advantages of the present invention will be evident to those skilled in the art from the following description of a presently preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a detailed section view of a laminated fabric according to the present invention.
FIG. 2 shows a first step of assembly of the fabric shown in FIG. 1.
FIG. 3 shows a second step of assembly of the fabric shown in FIG. 1.
FIG. 4 shows a third step of assembly of the fabric shown in FIG. 1.
FIG. 5 shows a fourth step of assembly of the fabric shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment will be described with reference to the drawing figures where like numerals represent like elements throughout.
In describing the woven portions of the fabric herein, reference is made to the orientation of the yarns as used on a papermaking or other type of machine. Yarns oriented along the direction of travel of the fabric are referred to as machine direction or MD yarns; yarns which are transverse to the direction of the machine travel are referred to as cross machine direction or CMD yarns.
A preferred embodiment of a laminated fabric 1 of the present invention and a method for making the fabric 1 are illustrated in FIGS. 1-5. The laminated fabric 1 is constructed by combining a first endless fabric 10 with a second flat fabric 20. As best seen in FIG. 2, the first fabric 10 is woven to have a seamless tubular form in a conventional endless weaving process having MD yarns 12 and CMD yarns 14. Preferably, the first fabric 10 has a single layer weave with MD yarns 12 weaving in a simple plain weave, an over one and under one repeat pattern, with respect to CMD yarns 14. A double or triple layer weave may be substituted for the single layer weave to provide the laminated fabric 1 with addition void volume and caliper.
The second fabric 20 is an open flat fabric having MD yarns 22 and CMD yarns 24 interwoven in a conventional two CMD layer weave pattern. Preferably, every other MD yarn 22 is used to form a seaming loop 26 to define arrays of seaming loops 26 at both ends of the second fabric 20. The non-loop forming MD yarns are woven to retain the endmost CMD yarns 24. Although a double CMD layer construction is preferred, single or other multiple layer designs can also be incorporated depending upon the desired characteristics for the interior of the laminated fabric.
As best shown in FIGS. 1 and 4, the flat second fabric 20 is disposed within the interior of the endless woven first fabric 10 in a flat sandwich construction with the flat fabric's end loops 26 projecting through the endless fabric 10. Accordingly, the laminated multilayer fabric 1 includes top and bottom laminate layers defined by portions of the endless fabric 10 and an intermediate laminate layer defined by the flat fabric 20.
When combined with the flat fabric 20, the endless first fabric 10 forms a laminated flat fabric of substantially half the length of the endless first fabric 10. As described more fully below in describing the method of construction, at each end 19 of the collapsed first fabric 10, selected CMD yarns 15 are removed to enable the second fabric's end loops 26 to project through the first fabric 10. Accordingly, the ends of the laminated fabric are seamed by intermeshing the projecting second fabric end loops 26 and inserting a pintle yarn 28 through the intersecting loops as shown in FIG. 1.
When the laminated fabric 1 is used as a wet press felt base fabric, fibrous batt material 32 is applied to one or both sides thereof. A conventional needling process is used to attach the batting 32 to the laminated fabric 1. The needling also serves to bind the laminate layers together. Alternatively, batting can be applied by affixing the batt material 32 with an appropriate adhesive or resin. In alternate embodiments, sewing or stitching of the batt material 32 to the laminated fabric 1 is also possible. Once batting is applied, the fabric can be processed, for example, as taught in U.S. Pat. No. 4,902,383, to provide a uniform seam construction.
Construction of the laminated fabric 1 begins with endless weaving of fabric 10 to form a tubular fabric as shown in FIG. 2. The second fabric 20 is constructed in an open form with seaming loops 26 projecting from each end. The second fabric 20 may be flat woven with the seaming loops 26 formed by back weaving as illustrated in U.S. Pat. No. 5,092,373. Alternatively, the flat second fabric 20 may be made via endless weaving having the seaming loops 26 formed during the weaving process such as disclosed in U.S. Pat. No. 5,053,109. The first fabric 10 and second fabric 20 are preferably heat set after weaving in a conventional manner to stabilize their weave structure.
Both the first fabric 10 and the second fabric 20 are formed with the same width. The length of the second fabric 20 is carefully controlled in relation to the length of the endless fabric 10 such that the second fabric seaming loops 20 will properly project through the first fabric 10 while maintaining a uniform laminated structure without folds or buckles in the body of the laminated fabric. The length of the second fabric 20 is substantially half the circumferential length of the first fabric 10.
The first and second fabrics 10, 20 may be woven with yarns made of any of the common textile fiber polymeric materials, such as nylon, polyester, polyolefin and the like, as well as mineral and natural fibers. Specialty yarns of heat resistant material, steel, carbon or other alloys and polymers or a combination of polymers may also be used for specialized applications. The yarn structure itself may be defined by a single yarn such as a monofilament, or may be formed of several monofilaments, such as twisted or braided yarn. Staple fiber yarns and multifilament yarns may also be used.
In a preferred embodiment, the first fabric 10 is made of nylon CMD yarns having a 0.015 inch diameter woven 15 CMD yarns per inch and cabled nylon MD yarns, preferably 0.008/2/3 (6 ply cabled), woven 23 MD yarns per inch. A preferred construction of the second fabric 20 entails the use of nylon MD yarns having a 0.019 inch diameter woven 35 MD yarns per inch and two layers of nylon CMD yarns having a 0.019 inch diameter woven 17 CMD yarns per inch in each layer.
As shown in FIG. 3, the second fabric 20 is inserted into the interior of the first fabric 10. Referring to FIGS. 3 and 4, with the endless fabric 10 in a collapsed state, opposing folds or bends are formed to define opposing ends 19 of the collapsed structure. Selected CMD yarns 15 are removed in the area of the end folds 19 of the first fabric 10 in order to permit the second fabric end loops 26 to project therethrough. The related CMD yarns 15 may be manually stripped by hand. The number of CMD yarns 15 which are removed is dependent upon the size and spacing of the CMD yarns 15 in the first fabric 10 and the caliper of the second fabric 20. Preferably, the CMD yarn removal defines relatively vertically flat end surfaces 30 on the first fabric 10 which are butted together during seaming. Upon removal of the selected CMD yarns 15, the seaming loops 26 of second fabric 20 project as shown in FIG. 4. Preferably, the assembled laminated fabric is stitched at approximately 6 and 12 inches from its respective ends to secure the laminate layers defined by fabrics 10, 20 together. At approximately 12 inches from each end, six rows of yarn are stitched at 8.5 stitches per inch, such that the stitch points are embedded between the yarns on both surfaces of the laminated fabric 1. An additional row of stitching is then installed between the six rows of stitches and the ends of the laminated fabric 1. This insures that the component fabrics 10 and 20 will be restrained in a homogeneous structure.
As shown in FIG. 5, the two ends of the laminated fabric 1 are folded over to bring the loops 26 into close proximity to each other. The loops 26 are then intermeshed and a pintle wire or pin 28 is inserted through the loops 22 to seam the laminated fabric 1, as shown in FIG. 1. This causes the vertical surfaces 30 defined in the collapsed endless fabric 10 to become substantially butted together, preferably with at most a gap no greater than 0.015 inches between the two end surfaces 30. In this form, the laminated fabric 1 is approximately one-half the length of the endless fabric 10 as depicted in FIG. 2. The fibrous batting 32 is then needled onto the laminated fabric 1 to finish the press felt.
While the present invention has been described in terms of the preferred embodiment, other variations which are within the scope of the invention as outlined in the claims will be apparent to those skilled in the art. | An industrial conveying fabric having a laminated multilayer construction. The laminated fabric includes a first fabric having a tubular configuration that is flattened and a second open flat fabric disposed within the first tubular fabric. The opposed ends of the second fabric project through the first fabric and are joined together to seam the laminated fabric. Preferably, the laminated fabric is used as a base fabric for a papermakers wet press felt and has fibrous batting material needled thereto. | 3 |
This application is a divisional of U.S. Ser. No. 09/661,836 filed Sep. 14, 2000, by James Ronald Lawter and Stephen J. Comiskey, which claims priority to U.S. Ser. No. 60/153,892 filed Sep. 14, 1999.
FIELD OF THE INVENTION
The present application relates generally to formulations containing a tetracycline that are useful for treating or preventing mucositis.
BACKGROUND OF THE INVENTION
Mucositis is a dose-limiting side effect of cancer therapy and bone marrow transplantation and is not adequately managed by current treatment (Sonis, 1993a, “Oral Complications,” in: Cancer Medicine, pp. 2381-2388, Holand et al.; Eds., Lea and Febiger, Philadelphia; Sonis, 1993b, “Oral Complications in Cancer Therapy,” In: Principles and Practice of Oncology , pp. 2385-2394, De Vitta et al., Eds., J. B. Lippincott, Philadelphia). Oral mucositis is found in almost 100% of patients receiving radiotherapy for head and neck tumors, in about 40% of patients receiving chemotherapy, and in about 90% of children with leukemia (Sonis, 1993b, supra). Complications related to oral mucositis, though varying in the different patient populations, generally include pain, poor oral intake with consequent dehydration and weight loss, and systemic infection with organisms originating in the oral cavity leading to septicemia (Sonis, 1993b; U.S. Pat. No. 6,025,326 to Steinberg et al.). In addition to the oral cavity, mucositis may also affect other parts of the gastro-intestinal tract.
A variety of approaches to the treatment of oral mucositis and associated oral infections have been tested with limited success. For example, the use of an allopurinol mouthwash, an oral sucralfate slurry, and pentoxifyline were reported in preliminary studies to result in a decrease in mucositis. Subsequent randomized and controlled studies, however, have failed to demonstrate any benefit from treatment with these agents (Loprinzi et al., 1995, Sem. Oncol. 22 Suppl. 3): 95-97; Epstein & Wong, 1994, Int. J. Radiation Oncology Biol. Phys. 28:693-698; Verdi et al., 1995, Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 80:36-42).
Other therapies have been directed at decreasing oral flora and the extent of oral infections. Systemic treatment with G- and GM-CSF has been shown to result in a decreased incidence of oral mucositis, presumably by allowing for more rapid neutrophil recovery and thus an improved ability to combat infection, although it has been postulated that the CSFs may have a more direct effect on the oral mucosa (Chi et al., 1995, J. Clin. Oncol. 13:2620-2628). Nonetheless, in one study, GM-CSF was reported to exacerbate mucositis (Cartee et al., 1994, Cytokine 7:741-477). Benzydamine hydrochloride, a nonsteroidal drug with analgesic and antimicrobial properties, has been studied both in patients undergoing radiation therapy and in patients receiving intra-arterial chemotherapy (Epstein et al., 1986, Oral Surg. Oral Med. Oral Pathol. 62:145-148; Epstein et al., 1989, Int. J. Radiation Oncology Biol. Phys. 16:1571-1575) but without much success.
Chlorhexidine, an antimicrobial mouth rinse, has also been used extensively in the treatment and prevention of oral mucositis (Ferretti et al., 1990, Bone Marrow Transplan. 3:483-493; Weisdorf et al., 1989, Bone Marrow Transplan. 4:89-95). It has been noted, however, that the efficacy of chlorhexidine is significantly decreased in saliva, and that this compound is relatively ineffective against the Gram negative bacteria that tend to colonize the oral cavity in patients undergoing radiation therapy (Spijkervet et al., 1990, Oral Surg. Oral Med. Oral Pathol. 69:444-449). In addition, at least one study has shown that the use of chlorhexidine may be detrimental and result in a higher incidence of mucositis (Foote et al., 1994, J. Clin Oncol. 12:2630-2633).
Several studies have shown that the use of a vancomycin paste and antibiotic lozenges containing polymixin B, tobramycin and amphotericin B in patients undergoing myelosuppresive chemotherapy or radiation therapy can result in a decrease in oral mucositis and in the incidence of sepsis due to alpha hemolytic streptococci (Barker et al., 1995, J. Ped. Hem. Oncol. 17:151-155; Spijkervet et al., 1991, In: Irradiation Mucositis , Munksgaard Press, pp. 43-50).
Other methods of treating or preventing mucositis using a variety of formulations have been reported. U.S. Pat. No. 5,545,668 to Skubitz et al. describes formulations containing glutamine. U.S. Pat. No. 5,635,489 to Haley, U.S. Pat. No. 4,961,926 to Gabrilove, and U.S. Pat. No. 5,102,870 to Florine et al., describe treatments using formulations containing growth factors or stimulating factors. Formulations contain antimicrobial peptides such as protegrin as the effective ingredient have also been described by U.S. Pat. No. 6,025,326 to Steinberg et. al. A triclosan formulation for treating mucositis was reported in U.S. Pat. No. 5,945,089 to Libin.
Despite the clear need for therapeutic agents to treat oral mucositis, none of the treatments provide significant long-term relief or decrease the severity or duration of mucositis. As a result, there is no standard treatment for oral mucositis.
Rothwell and Spektor (Special Care in Dentistry, January-February 1990, pages 21-25) have shown that patients to whom an oral rinse containing tetracycline, diphenhydramine, nystatin, and hydrocortisone was administered developed less severe mucositis than patients receiving a control rinse. The concentrations of the active ingredients in this study were tetracycline, 500 mg; nystatin, 1,200,000 U; hydrocortisone, 100 mg; and diphenhydramine elixir, 10 ml made up to a total volume of 250 ml. The tetracycline was unstable in solution with the other ingredients and was therefore administered in a separate solution.
WO 99/45910 by Sonis and Fey describes a method for treating and preventing mucositis by administering a non-steroidal anti-inflammatory (NSAID), an inflammatory cytokine inhibitor, or a mast cell inhibitor and second different therapeutic agent which is an NSAID, an inflammatory cytokine inhibitor, a mast cell inhibitor, a matrix metalloproteinase (MMP) inhibitor or a nitric oxide inhibitor. There are further claims where the MMP inhibitor is a tetracycline. These complex mixtures appear to reduce mucositis in animal models but the relative efficacies of the different active agents and effective dosages are unclear. Most of the active ingredients have side effects if absorbed systemically at effective dosages. Only the compositions containing the tetracyclines appear to significantly reduce the symptoms of the mucositis.
It is therefore an object of the present invention to provide a method and composition to decrease the duration and/or severity of mucositis by administering a composition containing a tetracycline as the active ingredient which is not absorbed systemically.
It is a further object of the present invention to provide a treatment that is safe, efficacious and easy for the patient to use.
SUMMARY OF THE INVENTION
Mucositis is treated and/or prevented by administrating to a patient a formulation comprising a tetracycline that is poorly absorbed from the gastro-intestinal tract. The tetracycline may be in the form of a pharmaceutically acceptable salt or a base. The formulations may optionally also contain an antifungal agent to prevent fungal overgrowth due to reduction in the normal oral flora by the tetracycline. Such compositions have the advantage of treating the entire gastrointestinal tract since the active ingredient is not removed from the tract via absorption. Further, such compositions minimize systemic exposure and accompanying side effects.
DETAILED DESCRIPTION OF THE INVENTION
I. Topical Tetracycline Formulations
Topical formulations for treating mucositis have been developed. These include as the active ingredient to treat the mucositis a tetracycline type compound that is poorly absorbed when administered orally or topically to the mucosa, a carrier which may be a solvent or suspending agent and include excipients modifying the viscosity, taste, stability, adherence or release properties, and optionally an anti-fungal agent.
A. Tetracyclines
As used herein, tetracyclines include compounds that may or may not have antibiotic activity. The tetracyclines described herein are those which are poorly absorbed when administered orally. Compounds which have bioavailibilities of about 10% or less are considered to be poorly absorbed. The tetracyclines are known to have pharmacological activities such as matrix metalloproteinase, nitric oxide synthetase and caspase inhibition that are independent of their antibiotic properties. These activities may be important in the treatment and prevention of mucositis. It is known that these pharmacological activities may be associated with tetracyclines that do not have significant antibiotic properties.
Tetracyclines are defined by the following structure:
wherein R 1 -R 5 may be a hydrogen atom, a halogen atom, a hydroxyl group, or any other organic composition comprising from 1-8 carbon atoms and optionally include a heteroatom such as nitrogen, oxygen, in linear, branched, or cyclic structural formats.
A wide range and diversity of embodiments within the definition of the above structure as are described within Essentials of Medicinal Chemistry John Wiley and Sons, Inc., 1976, pages 512-517, the text of which is incorporated by reference herein. Preferably R 1 and R 2 are hydrogen or a hydroxyl group; R 3 is hydrogen or a methyl group; R 4 is a hydrogen atom, a halogen, or a nitrogen containing entity; and R 5 is a hydrogen atom, or nitrogen containing ring structure. The commonly known tetracycline analogues and derivatives include the following: oxytetracycline; chlortetracycline; demeclocycline; doxycycline; minocycline; rolitetracycline; lymecycline; sancycline; methacycline; apicycline; clomocycline; guamecycline; meglucycline; mepyclcline; penimepicycline; pipacycline; etocycline, penimocycline, and meclocycline.
Tetracycline derivatives that can be used as described herein, include tetracycline derivatives modified at positions 1 through 4 and 10 through 12, although these modifications may result in reduction in antibiotic properties, according to Mitscher, et al., J. Med. Chem. 21(5), 485-489 (1978). The configuration of the 4 carbon is important to the antibiotic properties of the tetracyclines. For the antibiotic tetracyclines, carbon 4 is in the S configuration. The 4-epimers of the tetracyclines, which have the R configuration at the 4 carbon, have significantly reduced antibiotic activity. Other such non-antibiotic tetracycline analogs include the 4-de(dimethylamino) derivatives of the tetracyclines listed in the above paragraph. Specific examples include: 6-demethyl-6-deoxy-4-dedimethylaminotetracycline; 6-demethyl-6-deoxy-4-dedimethylamino-7-dimethylaminotetracycline; 6-demethyl-6-deoxy-4-dedimethylamino-7-chloro-tetracycline; 4-hydroxy-4-dedimethylaminotetracycline; 6a-deoxy-5-hydroxy-4-dedimethylaminotetracycline; 4-dedimethylamino-5-oxytetracycline, and 4-dedimethylamino-11-hydroxy-12a-deoxytetracycline. Further examples of tetracyclines with reduced antibiotic activity include 6-α-benzylthiomethylenetetracycline, 6-fluoro-6-demethyltetracycline, and 11α-chlorotetracycline.
Other tetracycline related compounds that can be used as described herein are the 9-((substituted)amido)tetracyclines. The latter include the compounds described in U.S. Pat. Nos. 5,886,175, 5,284,963, 5,328,902, 5,386,041, 5,401,729, 5,420,272, and 5,430,162.
Preferred poorly absorbed tetracyclines include compounds of the following structure:
wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 can be H, C1-C3 alkyl, phenyl, and aryl groups; and
wherein X is an H, alkyl, alkoxy, phenoxy, aryloxy, amino group, amide, acyl, and halo group; and pharmaceutically acceptable salts thereof.
The most preferred compound of this general structure is
wherein R 1 , R 2 , R 4 , R 5 , R 6 , R 7 , and R 8 are H;
wherein R 3 is CH 3 ; and
wherein X is a chloro group. The generic name for this compound is meclocycline.
The preparation of meclocycline and its analogs and derivatives are known. For example, U.S. Pat. No. 3,966,808 to Luciano discloses methods for manufacturing 6-methylenetetracyclines.
B. Pharmaceutically Acceptable Carriers
The formulations may be prepared as a liquid, semi-solid, or solid containing an amount of a poorly absorbed tetracycline that is effective to treat or prevent mucositis. Generally, these compositions contain about 0.001 to 1 mg/mL of the tetracycline.
The compositions are topically administered to the oral mucosa and then swallowed. Formulation types suitable for this route of administration include liquids applied as mouthrinses; solid dosage forms that may dissolve in the mouth; and semisolids that may be applied to oral cavity surfaces.
Tetracyclines in general may not be sufficiently stable in aqueous solutions to permit formulations with long shelf lives at room temperature, i.e. a year or more, to be prepared. Stability of the tetracyclines varies greatly with structure. However, solids for re-constitution as aqueous based solutions prepared either by the patient or by a pharmacist prior to administration to the patient can be used, even for the least stable members of the class. Also polyvalent metal ion complexes may be prepared that are stable in contact with water at room temperature for two years or more. Examples are the calcium and magnesium complexes. These complexes may be suspensions in water.
The stability of the tetracyclines in aqueous solutions is pH dependent. Procedures for choosing the optimum pH and buffering agents are well known. Other factors that affect stability in solution are also well known. For example, antioxidants may be added to reduce the rate of degradation due to oxidation.
In addition to the tetracycline and antifungal agents, an aqueous liquid preparation may contain buffers, surfactants, humectants, preservatives, flavorings, stabilizers (including antioxidants), colorants, and other additives used in preparations administered into the oral cavity.
The compositions used as mouthwashes preferably should have a pH of 3.5 to 8. A pH of 4 to 6.5 is most preferable. A preparation having a pH of less than about 4 would be likely to cause a stinging sensation. Furthermore, the preparations having a higher pH are often unpleasant to use. The active agents need not be in solution to be effective. The active agents may be present wholly or in part as suspensions in aqueous solutions used as carriers to provide liquid compositions.
The preparations are buffered as necessary to provide the appropriate pH. Appropriate buffer systems include citrate, acetate, tromethamine and benzoate systems. However, any buffer system commonly used for preparing medicinal compositions would be appropriate. While the vehicle used generally is primarily water, other vehicles may be present such as alcohols, glycols (polyethylene glycol or polypropylene glycol are examples), glycerin, and the like may be used to solubilize the active agents. Surfactants may include anionic, nonionic, amphoteric and cationic surfactants, which are known in the art as appropriate ingredients for mouthwashes.
Liquid formulations may contain additional components to improve the effectiveness of the product. For example, component(s) may be added to increase viscosity to provide improved retention on the surfaces of the oral cavity. Suitable viscosity increasing agents include carboxyalkyl, hydroxyalkyl, and hydroxyalkyl alkyl celluloses, xanthan gum, carageenan, alginates, pectins, guar gum, polyvinylpyrolidone, and gellan gums. High viscosity formulations may cause nausea in chemotherapy and radiation patients and are therefore not preferred. Gellan gums are preferred as viscosity modifying agents since aqueous solutions containing certain gellan gums may be prepared so that they will experience an increase in viscosity upon contact with electrolytes. Saliva contains electrolytes that will interact with such a gellan containing solution so as to increase their viscosity.
Flavorings used in the mouthrinse art such as peppermint, citrus flavorings, berry flavorings, vanilla, cinnamon, and sweeteners, either natural or artificial, may be used. Flavorings that are known to increase salivary electrolyte concentrations may be added to increase the magnitude of the viscosity change. The increased viscosity will promote retention of the solutions in the oral cavity and provide greater effectiveness due to increased contact time with the affected tissues.
In order to improve the patient acceptability, it is desirable to add an appropriate coloring and/or flavoring material. Any pharmaceutically acceptable coloring or flavoring material may be used.
Additional antimicrobial preservatives may be component of the formulation in cases where it is necessary to inhibit microbial growth. Suitable preservatives include, but are not limited to the alkyl parabens, benzoic acid, and benzyl alcohol. The quantity of preservative may be determined by conducting standard antimicrobial preservative effectiveness tests such as that described in the United States Pharmacopoeia.
Suitable solid dosage forms include powders or tablets that are designed for constitution as solutions by dissolution or suspension in a liquid vehicle and include troches, pastilles or lozenges that dissolve slowly in the mouth. For convenience of use, solids designed to be dissolved to prepare a liquid dosage form prior to administration preferably are rapidly dissolving. Technologies to produce rapidly dissolving solids are well known in the art. These include spray-drying, freeze-drying, particle size reduction and optimizing the pH of the dissolution medium.
The solubilities of tetracyclines are a complex function of pH since they have several ionizable functional groups. Tetracyclines generally have a minimum in their pH-solubility curves between a pH of 3 and 6. The rate of dissolution of acidic salts may be increased by dissolving in a neutral to basic buffer. Dispersal of such salts may optimally be done at low pH.
C. Other Active Agents
Other medicinal agents may be added for purposes of alleviating other undesirable conditions in the mouth. Such agents may include, for example, local anesthetics, antibacterial agents, and emollients, as well as anti-fungal agents.
Anti-fungal Agents
Antibiotic tetracyclines applied topically in the oral cavity may reduce the number of susceptible flora to such an extent that competitive conditions that hold non-susceptible organisms in check may not be effective. In particular, fungi, which are not susceptible to tetracyclines, may increase drastically in number. To avoid this, an antifungal agent may be added to the composition. Examples of antifungal agents that have been shown to be effective in preventing or treating fungal overgrowth are nystatin and clotrimazole. These agents may be added to a liquid tetracycline dosage form as a powder to form a suspension. The approved dosage for Clotrimazole, 10 mg is three times a day for mucositis. The approved dosage of Nystatin is 200,000 to 400,000 units, 4 to 5 times a day for up to 14 days in pastilles.
Examples of local anesthetics are lidocaine and a eutectic mixture of lidocaine and prilocaine. Lidocaine is administered in solution at a concentration of 2%, at a dose of 15 ml, at intervals of not less than three hours. The eutectic mixture is equimolar, administered at a total concentration of up to 5%. Either could be incorporated in an aerosol at similar doses.
II. Methods of Treatment
Methods of using the formulations disclosed herein generally involve applying the formulations topically to mucosal surfaces of the oral cavity and gastrointestinal tract. One to six applications per day beginning 24 hours before chemotherapy or radiation until conclusion of treatment are made. The typical volume of a mouthwash would be between 5-15 ml.
Therapy is continued for as long as the patient is receiving radiation or chemotherapy.
The present invention will be further understood by reference to the following non-limiting examples.
Methods and Materials
The following animal model was used to demonstrate the effectiveness of the poorly absorbed tetracyclines in treating mucositis.
Hamsters were randomly assigned to treatment groups with eight (8) animals per group. Each group was treated either with a drug solution or a control, water.
Animals were dosed three times a day for 22 days. The first dose was applied on day −1. Either a solution of the drug or water alone was applied in a volume of 0.1 ml three times per day.
Mucositis was induced by acute radiation exposure of the check pouch. A single dose of radiation (35 Gy/dose) was administered to all animals on Day 0. Prior to irradiation, animals were anesthetized with an intraperiotoneal injection of sodium pentobarbital (80 mg/kg) and the left buccal pouch was everted, fixed and isolated using a lead shield.
Beginning on day 6 and continuing every other day up to day 28, the cheek pouch was photographed. On days that photographs were taken, prior to the first dosing of the day, the animals were anesthetized using an inhalation anesthetic and the left cheek pouch of each animal was rinsed vigorously with sterile water to remove residual food debris or foreign contamination and blotted dry with a gauze sponge. The appearance of the cheek pouch was scored visually by comparison to a validated photographic scale, ranging from 0 for normal to 5 for severe ulceration (clinical scoring). In descriptive terms, this scale is defined as follows:
Score Description
0 Pouch completely healthy. No erythema or vasodilatation
1 Light to severe erythema and vasodilatation. No erosion of mucosa
2 Severe erythema and vasodilatation. Erosion of superficial aspects of mucosa leaving denuded areas. Decreased stippling of mucosa
3 Formation of off-white ulcers in one or more places. Ulcers may have a yellow/gray color due to pseudomembrane formation. Cumulative size of ulcers up to ¼ of the pouch surface. Severe erythema and vasodilatation
4 Cumulative size ulcers ¼ to ½ of the pouch surface. Loss of partially. Severe erythema and vasodilatation
5 Virtually all of pouch is ulcerated. Loss of pliability (pouch can only partially be extracted from mouth).
A score of 1-2 represents mild stage of the disease, whereas a score of 3-5 indicates moderate to severe mucositis.
These examples demonstrate that the tetracycline compositions significantly reduce the severity of mucositis when administered topically to the oral mucosa. Further they show that meclocycline which is poorly absorbed is as effective as a well absorbed tetracycline or tetracycline HO.
EXAMPLE 1
Treatment with Meclocycline Sulfosalicylate (0.1 mg/ml)
Eight hamsters were treated as described above with 0.1 mL of aqueous solutions containing 0.1 mg/mL meclocycline sulfosalicylate. The solution was prepared by dissolving meclocycline in an aqueous solution of a tromethamine buffer. Significantly lower scores were found in the group treated with the meclocycline solution than a group of hamsters treated with a placebo control consisting of the solution without meclocycline. Relative to the control group, the group treated with meclocycline had a reduction of more than 75% in the number of animal days with scores of 3 or more.
EXAMPLE 2
Treatment with Tetracycline Hydrochloride (0.1 mg/ml)
Eight hamsters were treated as described above with 0.1 mL of aqueous solution containing 0.1 mg/ml tetracycline hydrochloride. Significantly lower scores were found in the group treated with the tetracycline solution than a group of hamsters treated with a placebo control consisting of the solution without tetracycline. Relative to the control group, the group treated with tetracycline had a reduction of more than 75% in the number of animal days with scores of 3 or more.
These examples demonstrate that the tetracycline compositions significantly reduce the severity of mucositis when administered topically to the oral mucosa. Further they show that meclocycline which is poorly absorbed is as effective as a well absorbed tetracycline.
EXAMPLE 3
Freeze-dried Meclocycline Gellan Gum Formulations
Meclocycline hydrochloride powder formed by freeze drying in bulk is added to a solution containing gellan gum at a concentration of 0.5 mg/mL. The tetracycline concentration is 0.1 mg/mL. The solution also contains methyl and propyl parabens as antimicrobial preservatives at concentrations of 0.18% and 0.02%, respectively and tromethamine buffer.
EXAMPLE 4
Micronized Meclocycline Gellan Gum Buffered Formulations
Meclocycline hydrochloride powder formed by micronization is added to a solution containing gellan gum at a concentration of 0.5 mg/mL. The tetracycline concentration is 0.05 mg/mL. The solution also contains methyl and propyl parabens as antimicrobial preservatives at concentrations of 0.18% and 0.02%, respectively and tromethamine buffer.
EXAMPLE 5
Spray-dried Meclocycline Gellan Gum Formulation
Meclocycline hydrochloride powder formed by spray drying is added to a solution containing gellan gum at a concentration of 0.5 mg/mL. The tetracycline concentration is 0.01 mg/mL. The solution also contains methyl and propyl parabens as antimicrobial preservatives at concentrations of 0.18% and 0.02%, respectively and tromethamine buffer.
EXAMPLE 6
Micronized Meclocycline Buffered Formulation
Meclocycline sulfosalicylate powder formed by micronization is added to water. The suspension is added to a second solution containing a tromethamine buffer to form a mixture with a pH of approximately 8.
EXAMPLE 7
Meclocyline Coated Pellets
Pellets comprised of an inner core of tromethamine buffer and a coating of meclocycline hydrochloride embedded in methyl cellulose is added to water to form a mouth rinse. The concentration of the tetracycline in the solution is 0.1 mg/mL.
EXAMPLE 8
Meclocycline Tablets
A rapidly disintegrating tablet containing meclocycline sulfosalicylate is added to water. The tablet disintegrates and a second tablet containing a buffer is added to the solution to raise the pH so that the tetracycline rapidly dissolves.
EXAMPLE 9
Meclocycline Calcium Complex Suspension
A meclocyline calcium complex suspension is formed by addition of the hydrochloride salt of meclocycline to a solution of calcium lactate, which has been made basic, by the addition of sodium hydroxide. The solution also contained methyl and propyl parabens as antimicrobial preservative and EDTA and sodium bisulfite as antioxidants. The solutions were sparged with nitrogen to remove dissolved oxygen prior to addition of the sodium bisulfite. The mixture is deaerated.
EXAMPLE 10
Meclocycline Suspension
A suspension of meclocycline sulfosalicylate is formed by addition of micronized drug to an aqueous solution containing 0.5% gellan gum and methyl and propyl parabens as antimicrobial preservative.
EXAMPLE 11
Meclocycline Sulfosalicylate Suspension
A suspension of meclocycline sulfosalicylate is formed by addition of micronized drug to a unit dose quantity of an aqueous solution containing 0.5% gellan gum. No antimicrobial preservative is required since the formulation is used immediately after preparation.
EXAMPLE 12
Aeorosolized Micronized Meclocycline
A metered dose aerosol container is filled with micronized meclocycline sulfosalicylate and a non-FREON™ propellant. The container is equipped with a valve for delivering 500 mcg per actuation. The container is also equipped with a tube for directing the aerosol to the interior of the mouth.
EXAMPLE 13
Meclocycline Oral Rinse Solution
A powder containing meclocycline hydrochloride and buffer to promote rapid dissolution is prepared by granulation. The powder is dissolved in water to form an oral rinse solution containing 0.05 mg/mL meclocycline.
EXAMPLE 14
Effervescent Tablet Containing Meclocycline Formulation
An effervescent tablet containing meclocycline sulfosalicylate and sodium bicarbonate. The tablet is dissolved in water to form an oral rinse solution containing 0.1 mg/mL meclocycline.
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the present application described herein. Such equivalents are intended to be encompassed by the following claims. | Mucositis is treated and/or prevented by administrating to a patient a formulation comprising a tetracycline that is poorly absorbed from the gastro-intestinal tract. The tetracycline may be in the form of a pharmaceutically acceptable salt or a base. The formulations may optionally also contain an antifungal agent to prevent fungal overgrowth due to reduction in the normal oral flora by the tetracycline. Such compositions have the advantage of treating the entire gastro-intestinal tract since the active ingredient is not removed from the tract via absorption. Further, such compositions minimize systemic exposure and accompanying side effects. | 8 |
RELATED PATENT APPLICATION
This is a continuation-in-part of patent application Ser. No. 609,611 filed May 14, 1984 now abandoned, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to determining and utilizing the amount of unspent zinc-based sulfide scavenger which is present in a water-based drilling fluid for adjusting the scavenging capability of the drilling fluid to the extent desired during the drilling of a well. More particularly, the invention relates to a relatively quick and accurate procedure which can be used in field locations.
A state of the art paper entitled "Chemical Scavengers for Sulfides in Water-Based Drilling Fluids" by R. L. Garrett, R. K. Clark, L. L. Carney and C. K. Grantham, Sr. in Journal of Petroleum Technology, June 1979, page 787, discusses the chemistry of commercial scavengers for water-based drilling fluids, the parameters that affect the reliability of such materials and the problems affecting scavenger use. On page 796, the authors point out that "From this state of the art review one can see that we believe more research is needed to develop scavengers and tests for scavenger content in muds that match more closely the qualities of an ideal scavenger."
U.S. Pat. No. 3,706,532 describes a method for determining zinc concentrations in aqueous mediums. A sample medium is acidified, treated with a buffered complexing agent to complex aluminum or iron ions, treated with an organo sulfur compound to complex copper ions, then analyzed by adding an indicator the color intensity of which is calibrated with respect to known concentrations of zinc. U.S. Pat. No. 3,928,211 describes a class of zinc carbonate, basic zinc carbonate and zinc hydroxide compounds effective for sulfide scavenging. U.S. Pat. No. 4,252,655 describes the removal or inactivation of hydrogen sulfide contamination by adding at least one organic zinc chelate.
SUMMARY OF THE INVENTION
The present invention relates to improving a process for drilling a well with an aqueous drilling fluid containing a zinc-based scavenger of sulfide ions. A determination is made of the amount of unspent zinc-containing sulfide-scavenging material present in the drilling fluid. A measured volume of the drilling fluid is mixed with a significantly larger number of volumes (such as about 6 to 10) of a selective solvent foz dissoIving zinc ions and establishing within the resulting mixture a pH (such as a pH of from about 4 to 6) at which substantially all of the zinc in the drilling fluid, except for that combined into zinc sulfide molecules, becomes dissolved in the liquid phase of the mixture. A portion of the resulting liquid solution is separated from the solid components of the drilling fluid and the amount of zinc contained in the solids-free liquid is determined in order to determine the amount of unspent zinc-containing sulfide scavenger in the drilling fluid. The amount of scavenger in the mud is then adjusted to the extent required to provide a capability of precipitating a selected amount of sulfide ions without involving a solids content capable of impairing the drilling fluid rheology.
In a preferred embodiment of the invention the drilling fluid sample is mixed with about 4 to 10 times its volume of glacial acetic acid, or a selective solvent which is substantially equivalent to glacial acetic acid with respect to selectively dissolving zinc ions which have not combined with sulfide ions. The concentration of zinc in the resulting solution is preferably measured with a portable X-ray fluorescence spectrographic unit which is, or is substantially equivalent to, a Portaspec Model 2501 portable X-ray spectrograph (available from Pitchford Scientific Instruments Division of the Hankison Corporation).
In a preferred procedure, for example, in situations in which the proportions found of unspent zinc based scavenger are relatively low, an augmentive test for total zinc (including that combined into zinc sulfide molecules) can be performed by (a) an X-ray fluorescence measurement, or equivalent measurement, of the zinc in the unleached drilling fluid or, (b) using as the solvent for dissolving zinc from the drilling fluid a strong acid, such as hydrochloric acid, as a solvent, for combined and non-combined zinc, prior to measuring the concentration of the zinc solution. Such an acid preferably has a normality of from about 1 to 3. The difference between the prior and augmentive tests will indicate whether the scavenger concentration was reduced by dilution of the drilling fluid or by combination with sulfide.
DESCRIPTION OF THE INVENTION
Applicants have discovered that possible needs for changing the concentration of zinc base scavenger in a drilling fluid can be accurately monitored at the well site so the corrections in the rate of scavenger addition can be properly initiated. This can be effected by utilization of the present process. This process enables the drilling fluid to be sampled at a selected frequency with the results of determinations of the concentrations of unspent scavenger promptly available to the mud engineers. For example, within about 30 minutes or so, based on such information, increases or decreases can be made in the rate of scavenger addition and for additions of scavenger-free fluid to the extent needed to quickly change that concentration to either avoid an impairment of the drilling fluid rheology or to quickly scavenge a sudden encounter of sulfide.
Experiments were conducted using samples of an aqueous drilling fluid typical of that used in drilling operations. Quadruplicate examples were performed on samples of that mud spiked with proportions of 1 lb. per barrel (ppb) of Sulf-X (a zinc based sulfide scavenger available from Imco Services, a Halliburton Company). The tests employed the following procedures, which are preferred procedures for use in the present invention.
SAMPLE PREPARATION
1. Measure 10 ml of stirred mud into a 10 ml graduated cylinder using
a pipet with the end of the pipet cut off to minimize any particle
size exclusion.
2. Transfer the measured mud sample to a 150 ml beaker.
3. Add 60 ml of glacial acetic acid to the mud sample.
4. Heat at about 110° C. with frequent stirring for 10-15 minutes.
5. Allow the solution to cool sufficiently to prevent damage to a plastic centrifuge tube.
6. Place a portion of the mud-acetic acid mixture into a plastic 50 ml centrifuge tube.
7. Centrifuge so that all the mud is firmly packed at the bottom of the centrifuge tube.
8. Accurately pipet 10 ml of the centrifuge solution into a Chemplex X-ray fluorescence counting vial using a 5 ml Finnpipette.
9. Cover the counting vial with polypropylene film, brace the film onto the vial with a small collar, and fix the film onto the vial with a large collar.
INSTRUMENTAL MEASUREMENTS BY X-RAY FLUORESCENCE
1. Position the element selector to Zn using the sidearm lever.
2. Open the sample compartment door.
3. Plug into a 11O V outlet and engage "Power" button. Wait for the "ready" light and let warm 10 minutes.
4. Place sample counting vials in the spring-loaded mount. Insert the mount into the sample chamber with the rounded edge of the stainless mount facing inward. [Note: Make sure no droplets are present on the undersurface of the polypropylene film. These droplets will cause an errant increase in count rate.]
5. Close the sample chamber door and check to see if the "X-rays on" indicator is illuminated. If it is not illuminated, the stainless planchet holder should be reinserted in the other direction.
6. With "X-rays on", adjust the current to read 0.5 milliamps.
7. Set the counting scaler on the front panel to 60 seconds.
8. Engage count pushbutton and record the final gross X-ray intensity counts on the digital readout.
9. Obtain gross X-ray counts for the glacial acetic acid blank and a calibration standard prepared y the dissolution of ZnO in glacial acetic acid.
10. To leave instrument in standby position, open the sample compartment door.
11. For longer periods of inactivity, turn down the current, turn off main power and unplug.
CALCULATIONS (based on the following conditions)
10 ml mud, 60 ml acetic acid, 10 ml aliquots in counting vial.
Calculations are not valid for variations from these amounts.
1. Determine net counts for samples and ZnO calibration standard by subtracting the glacial acetic acid blank counts.
2. Determine the mg of Zn in 10 ml mud sample by the following ratio: ##EQU1## 3. Determine ppb (pounds per barrel) Zn by multiplying the mg Zn in the 10 ml mud sample by 0.035. The factor 0.035 is derived from the following conversion: ##EQU2## 4. Determine ppb Sulf-X by multiplying ppb Zn by 1.67 [Sulf-X contains
60.0% Zn].
TEST RESULTS
The tests indicated the following:
Sulf-X was experimentally determined to be present at 0.97 ±0.09 ppb. These results indicate the accuracy and precision of the method to be within the 10 percent relative objective.
Additional experiments were designed to simulate situations where the scavenger containing mud had been totally exhausted by hydrogen sulfide intrusion. This was accomplished by spiking mud with 1 ppb zinc sulfide which is the product from the reaction of the zinc scavenger with sulfide. Duplicate analyses yielded unspent scavenger concentrations of 0.02±0.01 ppb indicating that the acetic acid leach is effective at differentiating spent and unspent zinc scavenger.
In a third experiment, unspiked mud was found to have 0.03 ppb unspent zinc scavenger which indicates that potential interferents inherent to the mud are virtually non-existent.
In general, the selective solvent for zinc ions can comprise substantially any buffered liquid having a composition and concentration capable of providing a pH of about 4 to 6 when one part by volume of a drilling fluid having a pH in the range of from about 9 to 12 is mixed with about 4 to 10 parts by volume of said liquid. Examples of suitable selective solvent solutions include: glacial acetic acid, 10% formic acid, and 0.0001 M hydrochloric acid.
In general, the concentration of zinc which becomes dissolved in the selective solvent can be measured by substantially any suitably accurate procedure. Procedures capable of being conducted in field locations are preferred. An example of such a procedure is described in "Colorimetric Determinations of Elements" by G. Charlot, Elsevier Publishing Company, 1964.
Suitable Compositions and Procedures for Use in the Invention
The present invention is applicable to substantially any process for drilling the borehole of a well with an aqueous drilling fluid in a location in which the wellbore may encounter water soluble sulfide ions such as those in hydrogen sulfide or salts containing HS - or S.sup.═. Such acids and salts commonly coexist in a subterranean sulfide-containing water system.
In a preferred embodiment of the invention, the above described analyses are conducted at the drilling site with a frequency which increases with the likelihood of the borehole encountering sulfide ions and/or increases in the extent by which the zinc-based scavenger is found to have been depleted by round trips of the circulating drilling fluid. The zinc-based sulfide scavengers are generally available as solids and can be added as dry solids through a hopper for mixing solids with the circulating drilling fluid. But, in a preferred procedure, the scavengers are preferably added in the form of slurries in aqueous liquids. In addition, as known in the art, a lignosulfonate treatment of the drilling fluid can be utilized for controlling any undesirable zinc-induced flocculation of mud components.
In general, the most commonly used zinc based sulfide scavenger is a basic zinc carbonate. It is a manufactured compound having a formula averaging about 3Zn(OH) 2 . 2Zn CO 3 . As known in the art, where desirable to minimize any adverse effects of zinc ions, those ions can be loosely bonded with organic compounds into the form of metal chelates. Commercially available zinc chelates are based on aliphatic amino acids or their salts. Such chelated zinc ions tend to avoid being captured on clay surfaces in a manner causing flocculation while still being available for precipitating sulfide ions. | The concentration of unspent zinc-based hydrogen sulfide scavenger in an aqueous drilling fluid is controlled by selectively extracting an unspent scavenger in a solvent, such as glacial acetic acid, measuring the concentration of dissolved zinc, for example, with an X-ray fluorescence spectrograph, and utilizing the results of the measurements to proportion the extent of changes to be made in the concentration of the scavenger. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a composition and method for treating composting material used for cultivating edible fungi such as mushrooms to significantly reduce the malodorous gases normally associated therewith, retain water in the fibrous component of the compost composition, and enhance the nutritional quality of the edible fungi without detrimentally affecting crop yield.
2. Description of Related Art
The composting of animal waste to create a suitable organic substrate in which to cultivate mycelia of edible fungi has long been the accepted practice. The process, on which there are several variations, is generally one of aerobic biodegradation, i.e., fermentation, and comprises the use of horse manure and poultry manure; straw or other carbohydrate-rich substances essentially containing cellulose, hemicellulose, and lignin; nitrogen-rich nutrients, e.g., cotton seed, sunflower seed, seed meals, brewer's grains, and urea; and inorganic conditioners, e.g., lime and gypsum. Broadly speaking, composting involves the fermentation of straw and animal manure over a period of approximately one month, with periodic turning and wetting to assure proper biological activity.
The straw or cellulosic material is wet with water prior to mixing to provide moisture to the fermenting microorganisms during the fermentation process. Such wetting usually requires copious amounts of water due to the waxy nature of the straw's surface. The excess water runs off into a catch basin, carrying with it residual manure solubles and suspended organic matter, causing an accumulation of odor-causing agents in the catch basin.
Mushroom cultivation has been an activity carried out in relatively remote rural areas. However, as these formerly remote locations have become more densely populated because of urbanization and because increased commercial demand for the produce has caused growers to greatly enlarge their processing and growing facilities, government entities and concerned neighbors have brought attention to the odors and runoff associated with the traditional methods commonly practiced in this agribusiness.
The odors are largely caused by volatile sulfur compounds released by the microbial action during fermentation. These include hydrogen sulfide, methyl mercaptan, dimethyl sulfide, carbonyl sulfide, carbon disulfide, and dimethyl trisulfide. Ammonia, and traces of acetone, butanone, 3-methylbutanone, and 2-pentanone, have also been identified in the gas emissions from compost stacks (Derikx et al. (1990) "Odorous Sulfur Compounds Emitted During Production of Compost Used As A Substrate In Mushroom Cultivation", Applied and Environmental Microbiology 56:176-180). It is feared that the water runoff may leach into the ground water and cause pollution of drinking water for livestock and humans alike.
Odor control in the field of animal waste composting for mushroom cultivation has been addressed from several points of view. Miller and Macauley (1989) "Substrate Usage and Odours In Mushroom Composting", Australian Journal of Experimental Agriculture, 29:119-124, report that the odor problems are directly associated with the compost formulations, and that by adjusting the activator (nitrogen-rich nutrient) constituent in relation to the total dry weight, one may achieve reduced odor emissions. U.S. Pat. No. 3,345,152 teaches a method of deodorizing manure and human excreta by distilling the waste material at temperatures of 400° F. and reintroducing the gaseous effluent--water removed--into the waste stream to be "bonded" thereto. The resulting odor is that of a tobacco- or barbeque-like smell. Whereas this method changes the odor to one less offensive, the heat of distillation would destroy the microorganisms required for aerobic fermentation.
Methods of mushroom growth activation have been reported in the patent literature and in scholarly journals. For example, U.S. Pat. No. 4,420,319 teaches methods of effecting greater yield in shortened periods by employing a multistage process of the introduction of a manufactured mushroom spawn activator in combination with a delayed-release nutrient particle. U.S. Pat. No. 4,990,173 teaches a nutrient supplement for enhancing the growth of mushrooms comprising a protein-rich material coated with a hydrophilic carbohydrate. U.S. Pat. No. 3,560,190 teaches the use of dry, friable, granular nutrient supplement comprising a blend of cottonseed meal, cottonseed oil, and a hardwood sawdust as an absorbent. The novelty of that teaching is evidenced by the increase in volume of the mushroom harvest. U.S. Pat. No. 4,370,159 further teaches an improved nutrient growth-stimulating additive for mushroom compost which comprises the mixing of materials including soy and/or cottonseed oil with soy protein concentrate, calcium caseinate, sodium acetate, and lecithin. Successful growth stimulation was achieved. U.S. Pat. No. 5,186,731 claims a method of cultivating mushrooms comprising mixing mushroom spawn with compost and an amount of supplement to enhance the yield of fruiting bodies, said supplement being a calcium and/or amine salt of an aliphatic, alicyclic or heterocyclic carboxylic acid. It further teaches that said acids may be mono- or dibasic, saturated or unsaturated, and have up to 20 carbon atoms. The amine salts of that invention comprise ethylamine, diethylamine, triethylamine, triethanolamine or ethylenediamine.
SUMMARY OF THE INVENTION
The compositions and methods of the present invention have been devised to eliminate the aforementioned problems associated with current cultivation methods, and to facilitate the production of mushrooms and other edible fungi having enhanced nutritional value. The present invention provides a cost effective method of composting animal waste matter with cellulose-containing material in a manner so as to eliminate the generation of malodorants and reduce significantly the water runoff problem associated with current commercial cultivation methods. The present invention also provides a method for cultivating mushrooms and other edible fungi having improved nutritional characteristics, i.e., greater protein content and lower sodium content.
Accordingly, it is an object of the present invention to provide a composition, comprising a non-ionic surfactant, an anionic surfactant, a carboxylic acid, a volatile oil, an amine, a nitrogen source, and water. The nitrogen source can be urea, nitrates such as NaNO 3 , Ca(NO 3 ) 2 , KNO 3 , etc.
Another object of the present invention is to provide a method of composting animal manure and cellulosic materials, comprising treating said animal manure and cellulosic materials with a composition comprising a surfactant, a carboxylic acid, a volatile oil, an amine, a nitrogen source such as urea, and water during formation of compost stacks.
Yet another object of the present invention is to provide a method of cultivating mushrooms or other edible fungi, comprising growing said mushrooms or other edible fungi on a compost of animal manure and cellulosic materials treated with a composition comprising a surfactant, a carboxylic acid, a volatile oil, an amine, a nitrogen source such as urea, and water during formation of said compost.
Further scope of the applicability of the present invention will become apparent from the detailed description provided below. It should be understood, however, that the detailed description and following specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration only since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description of the invention is provided to aid those skilled in the art in practicing the present invention. Even so, the following detailed description of the invention should not be construed to unduly limit the present invention, as modifications and variations in the embodiments herein discussed my be made by those of ordinary skill in the art without departing from the spirit or scope of the present inventive discovery.
The contents of each of the references cited herein are herein incorporated by reference in their entirety.
To accomplish the foregoing objectives, material comprising, for example, horse manure, poultry manure, an activator, and a stabilizer such as gypsum are mixed into stacks, and an aqueous composition comprising at least one non-ionic surfactant, at least one anionic surfactant, at least one carboxylic acid, at least one volatile oil, at least one amine, and a nitrogen source such as urea are added thereto to produce a compost. The activator is a nutrient enhancer, such as a brewer's grain, which contributes nitrogen and protein to the composting material. The stacks are aerated by turning the mixture on the second, third, sixth and eighth days, wetting the compost mix on the first turn with water, on the second turn with water or said aqueous composition, and on subsequent turns with water. Trays are filled on the eighth day, and the compost is pasteurized for seven days. The prepared compost is spawned by adding a suitable nutrient supplement at 4% of dry weight, and the trays are placed in a controlled environment for two weeks to allow the spawn to colonize the compost. The trays are cased with peatmoss and lime to a depth of approximately 1.25 inches, and placed in a growing area for fruit development.
The aqueous additive composition used initially, and optionally on the second turn, comprises an emulsion of the following components, which is completely miscible in water:
about 0.01% to about 5% by weight of a non-ionic surfactant;
about 0.2% to about 6% by weight of an anionic surfactant;
about 0.05% to about 3% by weight of a carboxylic acid, preferably an unsaturated fatty acid;
about 0.05% to about 3% by weight of a volatile oil, preferably having a functional group containing oxygen, e.g., an epoxy, peroxy, hydroxyl, carboxyl, carbamyl, or carbonyl group;
about 0.1% to about 5% by weight of an amine selected from the group consisting of a mono-, di-, and tri-alkanolamine;
about 0.15% to about 2% by weight of a nitrogen source such as urea, NaNO 3 , Ca(NO 3 ) 2 , KNO 3 , etc.; and
water in an amount to make the balance of 100%.
In practice, the emulsion is premixed as a concentrate and diluted prior to application. Thus, the concentrations indicated above represent, at the low end, the final concentrations as actually applied to the material to be composted; at the high end, these concentrations represent concentrations prior to dilution and application. Concentrations between these endpoints can also be employed in practice.
The emulsion is applied to the compost at a rate of about 6 to about 10 liquid ounces per pound of compost, more preferably at a rate of about 8 liquid ounces per pound of compost.
The additive composition of the present invention is formulated having as its base a surfactant blend that is compatible with the biological process of fermentation of animal waste and cellulosic materials.
The surfactants are selected from those which are biodegradable, emulsifiers, as well as wetting agents.
Non-Ionic Surfactants
Non-ionic surfactants useful in the present invention include, but are not limited to, amides and esters of aliphatic, alicyclic, and aromatic acids, polyglycol ethers, and alkylphenol esters.
Preferred non-ionic surfactants useful in the present invention are the amides of fatty acids and the polyglycol ethers. Most preferred are cocamide, lauramide, oleamide and stearamide of mono- and diethanol amine.
Anionic Surfactants
Anionic surfactants useful in the present invention can be selected from the group consisting of ammonium, amine, and alkali salts of aliphatic, alicyclic, aromatic, alkylaryl, and alkyl ether sulfonates and sulfates.
The preferred anionic surfactant used in the present invention is at least one member selected from the group consisting of an alkylbenzene sulfonate, an alkyl sulfate, and an alkyl ether sulfate. Of particular utility are sodium, ammonium, monoethanol amine, diethanol amine, and triethanol amine salts of dodecyl benzene sulfonic acid, lauryl sulfuric acid, and lauryl ether sulfuric acid.
Carboxylic Acids
Carboxylic acids useful in the present invention are straight or branched chain, saturated or unsaturated carboxylic acids containing from two to twenty carbon atoms. Such acids can be mono-, di-, or tribasic, and can be used in combination with other similar carboxylic acids. Examples of suitable carboxylic acids include acetic, propionic, butyric, valeric, caproic, caprylic, nonylic, palmitic, stearic, arachidic, glycolic, suberic, citric, oleic, linoleic, and linolenic acids.
Of particular utility in the practice of the present invention is the use of vegetable oils such as corn, olive, cottonseed, and linseed oil. These oils, singularly or in combination with each other and/or with the carboxylic acids noted above, e.g., citric acid, provide the desired results of odor suppression and nutrition enhancement.
Volatile Oils
The volatile oil component of the composition of the present invention is at least one volatile oil having a functional group containing oxygen, e.g., an epoxy, peroxy, hydroxyl, carboxyl, carbamyl, or carbonyl group.
Useful volatile oils include, but are not limited to, the oils of eucalyptus, peppermint, spearmint, and others containing as a major component a C 10 terpene containing a functional group containing oxygen as described above. Such other volatile oils include, for example, terpin, terpineol, boreol, citronellal, citronellol, geraniol, linalool, menthol, 1-menthone, nerol, rhodinal, and rhodinol.
Other oils useful in the present invention are terpenes having olefinic bonds, e.g., limonene, pinene, and terpinene.
Amines
Amines useful in the present invention include at least one primary, secondary, or tertiary alkanol amine. Monoethanol amine, diethanoi amine, and triethanol amine are preferred.
Nitrogen Sources
Nitrogen sources useful in the present invention include, for example, at least one member selected from the group consisting of urea, NaNO 3 , Ca(NO 3 ) 2 , KNO 3 , etc.
Compost
The composition of the compost is not limited in any way, and can vary according to the practice of the composter or grower.
EXAMPLE 1
For purposes of illustration, a formulation was chosen which represents a typical compost mix. The practice of the present invention is not limited to this compost, but is useful on any compost mix for the cultivation of mushrooms or other edible fungi wherein animal manure and straw are the base components.
The compost comprised a mixture of wheat straw, horse manure, poultry manure, brewer's grain, and gypsum. The formulation of said compost is shown in Table 1.
TABLE 1______________________________________Formulation of Wheat Straw Bedded Horse Manure CompostWet Wgt % H.sub.2 O Dry Wgt % N Total N______________________________________Horse 350 23 269.5 1.0 2.695manurePoultry 40 9 36.0 5.2 1.872manureBrewers' 10 6 9.4 5.0 0.470grainGypsum 12 0 12.0 -- --Totals 326.9 5.037______________________________________ % N = 5.037/326.9 = 1.54
wherein wet weight and dry weight are in pounds, and wherein the total nitrogen is also in pounds, as derived from the percentage of dry weight. For example, in this case, where 36 pounds of poultry manure were employed, 36 pounds×0.052=1.872 pounds.
EXAMPLE 2
Manure compost stacks of Example 1, weighing approximately 412 pounds, were wetted at formation with either water (control) or the aqueous emulsions shown in Table 2. The emulsions were applied to the compost at at a rate of about 8 liquid ounces per pound of compost.
TABLE 2______________________________________Composition of Compost Odor-Suppressing Emulsions #1 #2 #3______________________________________Sodium docecyl 0.16% by wt. 0.1% by wt. 0.35% by wt.benzene sulfonateSodium lauryl ether 0.21 0.13 0.40sulfateDEA cocamide 0.02 0.012 0.05Diethanol amine 0.025 0.015 0.05Urea 0.015 0.01 1.0Citric acid -- 0.15 0.25Corn oil 0.05 -- --Oleic acid -- 0.05 0.1Oil of eucalyptus 0.05 0.03 0.075a-Terpineol -- 0.045 0.075(+)-Limonene -- 0.02 0.05______________________________________
The control stack was prepared in every way similar to the experimental stacks, with the exception that water was used in the initial wetting and at each successive turning.
The results for all stacks in terms of odor, temperature, organic content, color, and texture followed an expected course, without significant variance from the standard commercial product.
The dry ingredients accepted 45 to 47 gallons of water or compositions #1, #2, and #3, respectively. The stacks were allowed to stand for forty-eight hours while internal heat developed, rising to a temperature of 163° F. The compost was turned with wetting on days 2, 3, 6, and 8. Temperature were monitored during composting. The peak internal temperature achieved prior to the second turning was 156.5° F. Subsequent turnings were made on the sixth and eighth days of the process, with the eighth day's material being filled into trays and placed into a controlled environment to be pasteurized.
Seven days later, the trays were spawned using a commercial spawn, Lambert 932, and the compost was supplemented with Campbell's Fresh, Inc.'s "S-41" at 4% of the compost dry weight. Once prepared, the trays were placed into another controlled environment for two weeks at a temperature of 78° F. with daily over-rides of 83° F. to allow colonization of the spawn (spawn run). After spawn run, the compost was cased with a mixture of peatmoss and ground limestone to a depth of 1.25 inches, and the trays placed in a growing room using a completely randomized design.
The experimental design consisted of four treatments, each consisting of six replicate trays. Harvesting began on the nineteenth day and continued daily for six weeks. Mushrooms were harvested daily, and the mushrooms from each tray were counted and weighed. These yield data were accumulated into six seven day breaks (flushes), and the harvests for breaks 1-3 and 1-6 were summarized for statistical analysis.
Results
Compost and Composting
Chemical analyses for the four compost treatments are summarized in Tables 3 and 4, for filling and spawning, respectively.
TABLE 3______________________________________Chemical Analysis of Compost at FillingFILL pH % NH.sub.3 % N % H.sub.2 O % Ash % OM______________________________________Control 8.51 0.04 2.26 76.1 27.94 72.06#1 839 0.04 1.91 78.7 18.56 81.44#2 8.66 0.02 2.20 76.4 24.35 75.65#3 8.49 0.05 2.07 79.6 22.61 77.39______________________________________
TABLE 4______________________________________Chemical Analysis of Compost at SpawningSPAWN pH % NH.sub.3 % N % H.sub.2 O % Ash % OM______________________________________Control 7.69 0.03 2.34 73.2 29.3 70.7#1 7.52 0.03 1.94 73.4 25.1 74.9#2 7.68 0.01 2.22 72.5 29.4 70.6#3 7.77 0.06 2.03 75.1 26.8 73.2______________________________________
The amount of organic matter remained exceptionally high at spawning in the compost treated with composition #1, while the other values for the compost were within a normal range.
Odors
No foul odors were detected during any of the turnings in the compost treated with composition #1. Such compost smelled like hot straw at filling, with no ammonia smell. At filling, workers commented that the composts treated with compositions #2 and #3 had a more agreeable odor than compost made using plain water.
Compost Wetting
Compositions #1, #2, and #3 facilitated wetting of the dry compost ingredients, and the compost on subsequent turnings.
Dry straw is almost impossible to wet, with water beading and rolling off the straw. With the compositions of the present invention, water appeared to flatten and adhere to the straw much better than occurred in the water control. The improved water adherence was also observed on the first turning.
Composting Temperatures
Compositions #2 and #3 caused a slight suppression of Phase I composting temperatures, which was not observed with composition #1. During Phase II composting, all three compositions caused the compost to cook at a slightly higher temperature than the water control. Compost treated with composition #1 cooked at a slightly higher temperature than that treated with compositions #2 and #3.
Spawning, Spawn Run, and Casing
A slight hint of ammonia in the compost on spawning day was controlled by adding gypsum to the compost before spawning. This is a routine procedure widely practiced in the mushroom industry.
The four composts, i.e., that treated with water, and those treated with compositions #1, #2, and #3, were of good quality, having uniform color, moisture, and good texture. No adverse effects of the present compositions on the composts were observed, and the thoroughness of the spawn run two weeks later attested to the compost quality.
Mushroom Yield and Size
Mushrooms began picking on time, and the rhythm of the breaks was steady. None of the treatments had any negative effect on these parameters.
None of the treatments affected the average size of the mushrooms, i.e., mushrooms per pound. Yields were generous in all treatments, and the treatments did not affect either the yield or the size of the mushroom crop as shown in Table 5.
TABLE 5______________________________________Mushroom Yield and Size Control #1 #2 #3______________________________________Breaks 1 to 3 3.14 2.97 3.04 2.94Lbs. ft..sup.2-1Number Lb..sup.-1 53 55 58 50Breaks 1 to 6 3.76 3.75 3.43 3.53Lbs. ft..sup.2-1Number Lb..sup.-1 48 49 53 46______________________________________
Nutritional Value of Mushrooms
In order to determine if the compost treatments affected the nutritional value of the harvested mushrooms, mushrooms were collected from replicate trays at the time of the first break and analyzed. A composite sample was prepared by combining the samples from each replicate tray, and one composite sample, representing each compost treatment, was analyzed for a variety of nutritional components. The results are shown in Table 6, where the data are expressed in mg/100 grams fresh weight.
TABLE 6______________________________________Nutritional Characteristics of Mushrooms HarvestedFrom Compost Treated With Odor-Suppressing Emulsions Control #1 #2 #3______________________________________Moisture 92.5 92.2 92.1 91.9Ash 0.51 0.55 0.60 0.60Total 4.7 4.6 4.6 4.8CarbohydratesEst. caloric 29.5 29.9 30.7 31.2valueCalcium 9.5 10.1 9.6 7.6Iron 0.2 0.2 0.2 0.3Sodium 10.7 4.2 3.5 3.1Dietary fiber 2.3 2.2 2.1 2.3Protein 2.0 2.5 2.5 2.5Fat (acid 0.3 0.2 0.3 0.2extract)Fructose 0.1 0.2 0.2 0.2Dextrose 2.0 1.9 1.9 1.7______________________________________
Mushroom sodium content was reduced between 60% and 71% by the use of the present compositions. Protein content was increased 25%.
Summary of Results
1. Wetting of the compost was enhanced, both at the initiation of composting, and during subsequent steps of composting. No beading of water upon wetting of the straw material occurred. Instead, the water soaked into the substrate, resulting in more complete wetting, with less water run-off;
2. Foul odors, including ammonia odors, normally detected during turnings, were eliminated, leaving only the smell of "hot straw." Composition #1 was particularly effective in this respect;
3. Composting temperatures ran slightly higher than those in the water-only control stack;
4. Chemical analysis revealed that the compost treated with composition #1 was of exceptionally good quality, with uniform color and moisture, good texture, and increased organic content compared to the control;
5. Mushroom yield was generous, and compared well with or exceeded conversions measured at commercial farms. There were no adverse effects on crop yield or mushroom size;
6. Mushrooms grown on compost produced via the present novel treatment of the cultivation substrate contained 60% to 71% less sodium than mushrooms produced by conventional methods, and 25% more protein.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | Provided is a composition comprising a non-ionic surfactant, an anionic surfactant, a carboxylic acid, a volatile oil, an amine, a nitrogen source, and water. This composition is useful in treating composting material used for cultivating edible fungi such as mushrooms to significantly reduce the malodorous gases normally associated therewith. Mushrooms and other edible fungi grown on such treated compost material exhibit enhanced nutritional qualities, including lower sodium levels and increased protein levels compared to fungi grown on conventionally prepared compost. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. Pat. Application Ser. No. 07/861,284 filed Mar. 31, 1992 and now U.S. Pat. No. 5,231,434.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to projection and display systems, and more particularly to an overhead projector having a computer integrated therein with several output ports for external devices, and having a unique interface card which electronically connects the overhead projector to a liquid crystal display panel and simultaneously aligns the panel with the stage of the overhead projector. The panel may be slidably or pivotally attached to the overhead projector.
2. Description of the Prior Art
Overhead projectors (OHP's) are known in the art, and generally consist of a base having a stage area, a light source to illuminate the stage, and a projector head which houses mirrors and lenses designed to project any image placed on the stage area onto a display screen. OHP's may be either transmissive or reflective. In a transmissive OHP, the light source is under the stage area, i.e., opposite the side of the projector head. In a reflective OHP, the light source is above the stage area, typically near or even in the projector head, and the stage has a mirror-like surface to reflect the light back toward the head.
Use of OHP's has recently expanded from the traditional projection of images printed on transparent films, to the projection of images which are stored in machine-readable form (e.g., on magnetic or optical disks) and which are presented by means of a light-transmissive liquid crystal display (LCD) panel which is laid on the stage of the OHP. Exemplary LCD/OHP arrangements are shown in U.S. Pat. Nos. 4,846,694 and 4,944,578. In these patents, the LCD panels are controlled by external processors, such as a personal computer (PC). This type of system enhances the use of an OHP since the LCD controller may simultaneously direct the video output to other viewing devices, such as television monitors, which may be placed at several stations among the audience.
Several problems have arisen, however, in the use of LCD panels with OHP's. Foremost among these is the difficulty of storing and transporting the PC which controls the LCD panel, and connecting the PC to the panel. Three alternative systems have been devised to overcome this problem. The first system simply provides a portable "black box," much more compact than a normal PC and having simplified user inputs, which contains the minimum electronic components necessary to control the LCD panel, such as a microprocessor, memory storage and a monitor output port. An example of such a system is VIDEOSHOW (a trademark of General Parametrics Corp. of Berkeley, Calif.), wherein the graphic images are prepared at a normal PC, and then transferred to a magnetic (floppy) diskette which may be placed in the portable unit. The second system similarly incorporates certain components into the LCD panel, instead of the OHP. An example of an LCD panel having a microprocessor and memory means for storing images is disclosed in European Patent Application No. 89114916.3.
A third system for simplifying the LCD/OHP combination integrates certain computer components within the OHP. An example of this type of system is found in U.S. Pat. No. 4,882,599. This design, however, suffers from the drawback of the processor being limited to the single purpose of controlling the LCD panel. In other words, it is impossible to adapt the integrated OHP-computer for other uses such as remote communications, printing, etc. More generally, these functions are unavailable due to the lack of any external ports for connection of peripherals, such as a modem, printer, mouse, etc. Another disadvantage is that these systems do not support direct digital drive (for VGA-compatible panels), so that video signals must be converted from digital to analog and then back to digital again to interface to the LCD. Also, prior art OHP-computers are not compatible with conventional PC operating systems, such as PC-DOS, OS/2 (trademarks of International Business Machines), MS-DOS (a trademark of Microsoft Corp.), DR DOS (a trademark of Digital Research, Inc.), or MACINTOSH system (a trademark of Apple Computers, Inc.), additionally limiting their usefulness.
A further inconvenience of using an LCD panel with an OHP relates to the physical attachment of the panel to the OHP, and the electrical connections between the panel, its controller, and the OHP. Those skilled in the art will appreciate the importance of properly aligning the LCD panel with the stage of the overhead projector. Misalignment can result in lower light transmission through the panel, leading to an inferior projected image, and heat management problems; this is particularly critical in stacked panel designs which are subject to parallax problems, and also when special optical components, such as fresnel lenses, are used with the OHP. While it is not terribly difficult to properly align a portable LCD panel on an OHP, the fumbling that often occurs in this step adversely detracts from the presentation, and this problem can be amplified depending upon the particular dimensions of the LCD panel and OHP being used. With respect to the problem of electrical interconnection, anyone who has made a presentation with an LCD/OHP system has experienced the confusion of trying to connect the various cables needed for power, video, LCD control and other accessories. This confusion leads not only to delays, but also presents a possible hazard of electrical shock to a user or damage to the equipment if the cabling is not properly connected. Additionally, the user must insure that the proper cables (i.e., terminal connectors) are provided for the particular computer/LCD ports being used.
The problems mentioned in the foregoing paragraph are avoided in systems wherein the LCD panel is permanently integrated with the OHP. See, e.g., U.S. Pat. Nos. 4,763,993 (FIG. 4b) and 4,880,303. The first of these devices, however, is less desirable since the LCD panel always remains in the optical projection path, even when a transparency, rather than the LCD panel, is being used to provide the image. This in turn results in lower light transmission (due to the use of polarizers in the LCD panel) and hence poorer contrast in the projected image. In the second of these devices, although the LCD panel can be hinged upwardly out of the optical projection path, its attachment to the OHP still leads to storage and transportation problems and, in both devices, the LCD panel is not removable and so cannot be used with other systems. The latter aspect of these devices can be considerably frustrating, e.g., when the LCD panel is properly functioning but the OHP is nonfunctional, which may have many causes including breakdown of electrical components/connections in the OHP, or breakage of optical components such as the lamp or lenses. Another disadvantage of the last two mentioned patents is that, when the LCD panel is moved to its upper position out of the optical projection path, it presents an obstruction which may prevent certain viewers in the audience from being able to see the projected image. The simplest solution to this problem is to make the LCD panel completely removable, but this solution leads back to the aforementioned problems of panel storage and cable interconnection. It would, therefore, be desirable and advantageous to devise an LCD/OHP system which would overcome all of the above limitations, particularly one which is easily adapted for use with either transparencies or an LCD panel, which provides means for conveniently storing the panel in a position which does not obstruct the projection screen from any viewing angle and further provides means for conveniently connecting the panel to the computer or controller.
SUMMARY OF THE INVENTION
The foregoing objective is achieved in a presentation system having an overhead projector specially designed to interface with a liquid crystal display panel. The OHP has an internal computer which is preferably compatible with conventional operating systems for personal computers, and has a plurality of output ports for connection to external accessories. The upper surface of the OHP base has a slot therein, proximate the stage area, for receiving an interface card which electronically connects the LCD panel to the internal computer. Thus, there is no need for any cabling in the system, other than the primary power cord exiting from the OHP base. Power is supplied from this cord to the OHP and computer, and to the LCD panel via the interface card. Use of an interface card to so provide the electrical connections also imparts the unexpected advantage of providing accurate alignment of the LCD panel with the OHP stage.
The LCD panel may further be pivotally or slidably attached to the OHP. In the pivoting embodiment, one corner of the panel includes a post which is removable engaged in a hole in the OHP stage, and the slot for receiving the card connector extends completely through the panel to allow downward insertion of the card through the slot, and into the OHP. In the sliding embodiment, the panel rests in or comprises a drawer which slides out of either side of the OHP base, and mechanical means may optionally be provided to actuate an auxiliary lens within the OHP body which reshapes the light beam based on the size and location of the panel window. In both embodiments, when the LCD panel is not in use, it acts as a shelf to support other articles, e.g., transparencies.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features and scope of the invention are set forth in the appended claims. The invention itself, however, will best be understood by reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view of the OHP/LCD system of the present invention, showing the interconnection between the OHP and the LCD panel by means of the interface card;
FIG. 2 is an elevational cross-section of the OHP base illustrating the internal computer;
FIG. 3 is a block diagram of the electronic components forming the internal computer in the preferred embodiment of the present invention;
FIGS. 4A and 4B are top plan views of the card connectors used in accordance with the present invention for analog and direct digital drive LCD panels, respectively;
FIG. 5 is a perspective view of another embodiment of the OHP/LCD system of the present invention, wherein the LCD panel slides out from the OHP base; and
FIG. 6 is a perspective view of yet another embodiment of the OHP/LCD system of the present invention, wherein the LCD panel swings away from the OHP stage.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the figures, and in particular with reference to FIGS. 1 and 2, there is depicted the presentation system 10 of the present invention. Presentation system 10 is generally comprised of an overhead projector (OHP) 12, a liquid crystal display (LCD) panel 14, and an interface or connector card 16 which provides the electrical connections between HP 12 and LCD panel 14. In the preferred embodiment, OHP 12 is a transmissive-type projector, and has all of the features of a conventional overhead projector, including a base 18 and a projection head 20 attached to base 18 by arm 22 (head 20 and arm 22 are omitted from FIG. 1 for simplicity). Conventional adjustment means 24 are used to raise or lower head 20, i.e., move it toward or away from base 18.
Base 18 houses a light source 26, a power supply 28 for light source 26, and appropriate optical components (such as a mirror 30 and fresnel lens 32) for directing, collecting and collimating the light towards a stage 34 (a transparent sheet, e.g., glass). When an image is present on LCD panel 14, or when a transparency is placed on stage 34, the image is collected and projected (to a nearby projection screen or surface) by conventional optics located in head 20. Base 18 also houses a computer 36, discussed below in conjunction with FIG. 3.
LCD panel 14 may also be any conventional liquid crystal display panel, with the exception of the added card edge connector as described further below. Panel 14 may provide gray-scale imaging, simulated color (yellow/blue), or full color, and may be "passive" or "active matrix" (using an array of thin-film transistors), and further may use various types of liquid crystals, preferably supertwisted nematic crystals. Prior art panels are also equipped with their own (conventional) control electronics which convert the video signals from the source (computer) into data which can be transposed to the pixels in panel 14. Additional components may be used to adjust contrast, intensity, color, etc., and allow remote control. Means may also be provided to keep the panel cool, such as cooling systems and/or use of cold filters as disclosed in U.S. Pat. No. 4,763,993. An exemplary LCD panel is sold by the Visual Systems Division of Minnesota Mining and Manufacturing Company (3M--assignee of the present invention) under model number 4180.
Referring now to FIG. 3, the preferred embodiment of computer 36 is described. Computer 36 includes a microprocessor 38 such as the AM286ZX integrated circuit available from Advanced Micro Devices of Sunnyvale, Calif. Several other conventional components are connected to microprocessor 38, including a clock 40, backup battery 42, dynamic random-access memory (DRAM) 44 for temporary data storage during program execution (preferably at least one megabyte), and read-only memory (ROM) 46 for permanently storing the basic input an output system (BIOS) software. Additional ROM 48 may optionally be provided to store conventional operating system software, including PC-DOS, MS-DOS, OS/2 and MACINTOSH operating systems. Computer 36 may include a plurality of expansion slots (not shown) for receiving circuit boards which add to the computer's functionality. For example, one of the slots could be occupied by a graphics adaptor, such a VGA (visual graphics adaptor) circuit board, providing enhanced graphical output for LCD panel 14. Rather than providing such a card, however, these functions have been integrated, in the preferred embodiment, in the mother board in an LCD/VGA controller 50 such as the CL-GD6410 controller available from Cirrus Logic of Fremont, Calif. This controller can provide output to both an LCD panel and a CRT monitor 72 simultaneously.
LCD panel 14, as well as other peripheral devices, are accessed via a controller 54, having a plurality of output ports 56 (serial and/or parallel) represented in FIG. 3 by double arrows; a satisfactory controller is the PC87310 controller available from National Semiconductor of Santa Clara, Calif. The peripheral devices (besides panel 14) include a keyboard 58, modem 60, remote control 62, printer/plotter 64, mouse (input pointing device) 66, floppy diskette drive 68 and hard disk drive 70. The latter two peripherals (which may be designed for either magnetic or optical media, e.g., CD-ROM) may be located within base 18, although floppy diskette drive 68 is of course externally accessible; although certain of the other peripherals could also be housed within base 18, they are preferably external to reduce space requirements for OHP 12. Most of the peripherals are optional, except that there should be at least one input device (mouse, keyboard or remote control), and there should further be at least one device for data transfer (floppy diskette drive or modem). Several of the peripherals (e.g., modem 60, remote control 62, or mouse 66) may be connected to controller 54 via an RS232 port. A port may also be provided to duplicate the video output to another CRT monitor. Other configurations for computer 36, including additional peripherals, will become apparent to those skilled in the art upon reference to the foregoing description, for example, a personal computer memory card interface adaptor (PCMCIA), an adaptor for a local area network (LAN), or even audio speakers. A port could also be provided for a card reader such as that described in U.S. Pat. No. 4,994,987.
The foregoing design has several advantages, the primary advantage being the spatial efficiencies associated with location of the computer components within base 18 of OHP 12. The integration of the computer and OHP simplifies storage and transportation of presentation system 10, and further protects computer 36 from direct physical damage. There are also efficiencies in manufacture, e.g., it is no longer necessary to provide a separate chassis or housing for computer 36. Moreover, the system setup is simplified since computer 36 is powered by the same power supply 28 which energizes light source 26. In other words, there is no need to provide a separate power connection to computer 36; power to all components is provided via a single electrical cord 74 which is connected to power supply 28 and has a plug at its distal end for connection to an external power source (i.e., conventional 110 AC voltage). It will also be appreciated that only one power outlet is consequently needed. It is also preferable to locate power supply 28 away from computer 36, as shown in FIG. 2, for safety reasons; as a consequence of this placement, certain agency (UL & VDE) manufacturing requirements may also be avoided.
A further novelty in the present invention relates to the connection of computer 36 to LCD panel 14, specifically, the use of connector card 16. By providing compact connection means which is also integrated into the physical design of system 10, the cabling problem associated with prior art systems is avoided. There is no possibility of connecting a cable improperly, of inadvertently disconnecting a cable, or of losing a cable altogether, and use of such a card connection generally increases the reliability of system 10. LCD panel 14 is also easily attached and detached from OHP 12, for example, when transparencies are to be used in lieu of panel 14. Moreover, the use of a connector card which is located proximate stage area 34 gives rise to the unexpected advantage of ensuring that LCD panel 14 is always properly aligned with respect to stage 34. In this regard, it is understood that a slot (not visible in the figures) is positioned on the lower surface of panel 14 at an appropriate location to optimize the alignment of the "window" of LCD panel 14 with stage area 34.
To this end, connector card 16 should be constructed of a rigid material, such as that forming the substrate for most printed circuit boards. Materials include phenolic-resin impregnated paper, acrylic-polyester impregnated random glass mat, epoxy impregnated paper, or epoxy impregnated fiberglass cloth. A plurality of conductive paths (metallic traces) are placed on card 16; the traces lead from the upper edge of the card to the lower edge, and are generally linear, although the traces could have turns or cross-overs as necessary to operatively connect panel 14 to computer 36. Card 16 could also be shielded to minimize interference from ambient electromagnetic signals, and/or keyed to allow insertion into the slot 76 in the upper surface of base 12. So-called "delta" card connectors are both shielded and keyed. It is preferable, however, to design a connector card having symmetric traces in order to avoid the need for polarization and eliminate concern over the insertion of card 16 into slot 76. Card 16 is preferably about 4 cm. long by 2.5 cm wide, with an approximate thickness of 1.5 mm. Of course, card 16 could be permanently fastened to base 16, but it is preferable to allow removal of the card to avoid breakage of the card during use or transportation.
The connection from card 16 is made to panel 14 and computer 36 using conventional card edge connectors 78. Satisfactory connectors are available from 3M's Electronic Products Division, part no. 3462-000. 3M also offers a keyed connector, part no. 3439-2. The number of connections (pins) are variable depending upon the particular LCD panel being used, although a 26-pin connector has been deemed acceptable for most uses. The preferred interconnections are best understood with reference to FIGS. 4A and 4B, to which attention is now directed.
FIG. 4A is a depiction of the connections in an exemplary card edge connector 78a, having 26 terminals, for an LCD panel designed to receive standard computer video output (e.g., VGA), which consists of several analog signals. Terminals so, 82 and 84 provide connections for the signals corresponding to the primary colors, viz., red, green and blue, respectively. Terminals 86, 88 and 90 are the grounds for these respective signals. Additional grounding terminals are provided at 92, 94, 96, 98, 100, 102, 104 and 106. Power is provided at terminals 108 (-5 volts), 110 (-5 v), 112 (+12 V), 114 (+12 V), 116 (+12 v), 118 (+12 v) , 120 (+5 v), 122 (+5 v), 124 (+5 v) and 126 (+5 V) . Horizontal and vertical synchronous control signals are provided via terminals 128 and 130, respectively.
FIG. 4B is similar to FIG. 4A, except that the card-edge connector 78b of FIG. 4B is designed for LCD panels which are driven with direct digital signals.
FIGS. 5 and 6 illustrate alternative embodiments of the OHP/LCD system of the present invention which are the subject of this continuation-in-part application. FIG. 5 depicts the embodiment wherein the LCD panel 14' slides into the side of base 18' of OHP 12'. The sliding movement may be achieved by any convenient means, such as by making panel 14' into a drawer by attaching thereto rollers or splines which engage tracks 132 inside base 18' (or vice-versa). More preferably, however, OHP 12' is provided with a conventional drawer which can removably receive panel 14'. In this manner, panel 14' may be completely removed from the OHP/LCD system and used in other presentation or display systems. OHP 12' may be constructed to accommodate insertion of panel 14' in any of the four sides of base 18'; however, it preferably is inserted into the left or right side. In some OHP's, the projection head 20 may be lowered for storage or transportation by pivoting arm 22 downward, where it often rests alongside of base 18'. In such a case, panel 14' would be inserted On the side opposite arm 22.
The embodiment of FIG. 5 preferably takes advantage of the benefits associated with connector card 16. In this embodiment, however, card 16 is permanently attached to the inside of base 18', and the slot in panel 14' for receiving card 16 is located in the side of the panel, i.e., the card is horizontal (parallel to stage 34), as opposed to the vertical orientation of FIG. 1. The slot in panel 14' may have a slightly flared entrance to facilitate insertion of the card. Stop pads (not shown) may be provided inside base 18' to minimize damage if the panel is inserted into the base with excess force. Means may be provided to signal to the user that the panel has been properly inserted, e.g., a plastic tine may register with an indentation in panel 14' to provide an audible click when the panel is fully inserted. A cover may also be provided for the drawer to protect the panel; for example, a tambour which rolls up inside base 18' would come out when the drawer is pulled, and be spring loaded so that it automatically retracts.
When panel 14' is inserted in base 18', some light from lamp 26 is wasted since the optics are designed to fully illuminate the area defined by stage 34, but the window of panel 14' is typically smaller than stage 34, and this window is now closer to lamp 26 and the condenser lens. To optimize the amount of light striking the window of panel 14', an auxiliary lens 134 may be used. Any convenient means may be used to flip auxiliary lens 134 into and out of the optical path when panel 14' is inserted or removed from base 18'. For example, auxiliary lens 134 may be held by a lever 136 which is actuated by a simple linkage as panel 14' is inserted into the OHP. Biasing means (such as a spring) would retract lever 134 when the panel is removed. Auxiliary lens 134 is designed to focus the light more narrowly at the window of panel 14', so its specific design details depend upon the size and location of the window, as well as the optical design of the primary condenser lens.
Those skilled in the art will also appreciate that the system of FIG. 5 may eliminate certain components of the OHP/LCD system, specifically, a pair of Fresnel lenses. LCD panels typically require two such lenses, one at the bottom of the LCD stack and the other at the top of the stack. The lower Fresnel lens serves to collimate the light passing through the panel, while the upper Fresnel lens duplicates the purpose of Fresnel lens 32, viz., to condense the light/image toward projection head 20. Rather than placing these lenses in the LCD stack, they can be permanently located in the OHP, with a sufficient vertical spacing to allow insertion of panel 14' between the Fresnel pair. Provision of both Fresnel lenses in the OHP does not affect its performance when panel 14' is not in use. Placement of the panel in such a drawer would also eliminate the need for expensive tooling costs of the molded, polymeric cover provided on most panels.
Referring now to FIG. 6, another embodiment of the OHP/LCD system of the present invention is shown in which the LCD panel 14" is pivotally attached to OHP 12". In this exemplary embodiment, panel 14" is attached by means of a post or peg 138 which is removably inserted into a hole in the top of base 18". Peg 138 may itself be removable from panel 14" so that the panel may be used in other systems without mechanical interference from the peg. A reinforcing bar might be integrally formed with peg 138 to provide further support along the bottom of the panel. Since the panel is designed to swing in a horizontal motion, it is preferable to provide a slot 140 which passes completely through panel 14", to allow insertion of card 16" after the panel is moved to its operative position. Consequently, card 16" is slightly longer than the card 16 of FIG. 1. It is also understood that panel 14" could pivotally swing into the interior of base 18", rather than on top of stage 34, in a manner similar to FIG. 5, although this would require a slightly larger opening in the side of base 18" to accommodate the diagonal length of panel 14".
Several benefits are realized as a result of horizontally swinging the panel into place, in both embodiments of FIGS. 5 and 6. First of all, when the LCD panel is not to be used, it is easily removed from optical path to allow conventional usage of the OHP with transparencies, but the panel need not be completely removed, and so the user is not concerned with temporary storage of the panel. Nevertheless, the panel may be completely removed from the OHP for use with other systems. Also, when the panel is not in use, it does not present an obstruction to viewers of the projection screen, and it can be used as a shelf to support other articles, e.g., transparencies and pens. Finally, these systems still take advantage of the connector card to eliminate cabling difficulties.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. For example, those skilled in the art will appreciate that the present invention may also be applied to reflective-type overhead projectors and reflective-type LCD panels. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined in the appended claims. | An overhead projector (OHP) presentation system uses a liquid crystal display (LCD) panel to project electronically stored graphic images. The OHP preferably includes an integrated computer having a plurality of output ports for connection to various peripheral devices. A novel interface card is also used to provide electrical connections between the computer and the LCD panel, providing the further benefit of aligning the transmissive portion of the panel with the stage of the OHP. The LCD panel may be designed to swing horizontally into the optical path. This may be accomplished by providing a sliding drawer which inserts the panel within the body of the OHP, or by pivotally attaching the panel to the stage of the OHP. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] This invention relates to trailers and is particularly related to trailers used in transporting snowmobiles.
BRIEF SUMMARY OF THE INVENTION
[0005] Snowmobile users frequently use trailers to transport the machines from storage to a use location and return. It is not uncommon that one snowmobile or even as many as four to six machines are transported on a single trailer. Very few snowmobiles are capable of reverse travel so it frequently is a difficult task to load the snowmobile or snowmobiles on a trailer bed such that they can be readily removed. Generally the machines are simply dragged off the trailer when they are unloaded. The machines are heavy and cumbersome and it is not only hard work to drag them from the trailer, but it is also somewhat dangerous, particularly when such procedures may be taking place in snow storms or other inclement weather conditions. Also, it is very common that loading and unloading of the trailer may be taking place in locations affording limited mobility of the trailer or towing vehicle. For example the vehicle and trailer may be driven to the end of a single lane mountain road at which location it is necessary to unload the snowmobiles from the rear of the trailer. Or, the vehicle and trailer may be driven into a parking lot at a ski-resort, where parking space is at a premium and there is no alternative to dragging the snowmobiles from the rear of the trailer.
[0006] Trailers have been developed in the past that allow front ramps to be lowered into position allowing snowmobiles to be driven off the trailer at an angle that will afford clearance of the towing vehicle. This, of course requires side clearance alongside the tow vehicle to permit the machines to be run off the trailer. Often, such side clearance is not available and the user of the trailer must resort to dragging the transported snowmobiles from the rear of the trailer.
[0007] Principal objects of the present invention are to provide a trailer that can be used to transport snowmobiles, all-terrain vehicles and the like and that will provide for easy loading and unloading of the trailer.
[0008] Still other objects are to provide a trailer that will permit snowmobiles and ATV's to be driven onto the trailer and off of the trailer even when the vehicles do not have a reverse drive.
[0009] It is yet another object of the invention to allow loading and unloading of a trailer from any desired location around the trailer and from ground level or from a hillside, snow bank or other elevated terrain feature at the loading and unloading site.
[0010] Principal features of the invention include a trailer with a rigid, supporting, wheeled undercarriage and a trailer bed supported by bearings carried by the undercarriage. An electric motor rotates the bed on the bearings, through sprockets and a drive chain. An electrical switch operates to turn the motor on and off and a locking assembly is provided to secure the bed against rotation relative to the undercarriage during travel of the trail t.
[0011] Other objects and features of the invention will become apparent to those skilled in the art to which the invention pertains from the following detailed description and drawings, disclosing what is presently contemplated as being the best mode of the invention.
DRAWINGS
[0012] In the drawings:
[0013] [0013]FIG. 1 is a perspective view of the trailer of the invention;
[0014] [0014]FIG. 2 a similar view with the bed of the trailer rotated;
[0015] [0015]FIG. 3, a pictorial view showing the undercarriage and trailer bed;
[0016] [0016]FIG. 4, an enlarged view of the drive motor for the bed;
[0017] [0017]FIG. 5, an enlarged view of the front end of the undercarriage and trailer bed, shown fragmentarily, and the locking assembly;
[0018] [0018]FIG. 6, a reduced top plan view of the trailer;
[0019] [0019]FIG. 7, a side elevation view;
[0020] [0020]FIG. 8, an enlarged side elevation view of the coupling between trailer bed and drive sprocket; and
[0021] [0021]FIG. 9, a transverse section, taken on the line 9 - 9 of FIG. 7.
DETAILED DESCRIPTION
[0022] Referring now to the drawings:
[0023] In the illustrated embodiment, the trailer of the invention is shown generally at 10 . Trailer 10 includes a trailer bed 12 with a front protector/ramp 14 having a section 16 pivotally connected by hinges 18 to a front edge 20 of the bed 12 . A rear protector/ramp 22 has a section 24 that is similarly pivotally hinge connected at 26 to the rear edge 28 of the bed 12 .
[0024] Side rails 30 and 32 project upwardly from rails 34 and 36 at opposite sides of the bed 12 . Plates 38 project upwardly from ends of side rails 30 and 32 and locking pins 40 are inserted through plates 38 and frames 42 of the protector/ramps 14 and 22 . Upper sections 44 and 46 of the protector/ramps 14 and 22 are respectively hinged at 48 to the sections 16 and 24 .
[0025] The protector/ramps 14 and 22 are locked in a to the side rails in a raised position when snowmobiles are positioned on the trailer bed. In the raised position the protector/ramps hold the snowmobiles on the trailer and the front protector/ramp 14 protects the snowmobiles from slush and Either debris thrown up by the tow vehicle wheels. The protector/ramps 14 and 22 are pivoted downwardly and sections 44 and 46 are pivoted to form extensions of the sections 16 and 24 that will serve as extended access ramps for movement of snowmobiles onto and off the trailer bed. A trailer tongue 50 is connected to and projects from a front rail 52 of an undercarriage 54 beneath the trailer bed 12 . The usual trailer jack 56 is fixed to tongue 50 and a hitch coupler 58 is mounted to the end of the tongue remote from the front rail 52 for attachment to a tow vehicle (not shown).
[0026] Undercarriage 54 further includes a pair of spaced apart long rails 60 and 62 , a pair of spaced apart short rails 64 and 66 respectively welded to long rails 60 and 62 . A pair of leaf springs 68 and 70 are suspended by spring hangars 72 , 74 and 76 from each of the short rails and a pair of roles 78 and 80 with wheels 82 and 84 on the ends thereof are secured t) the springs by clamps 86 and 88 .
[0027] A gear motor 90 is bolted at 92 to a cross beam 94 interconnecting the long rails 60 and 62 and the output shaft of the motor has a small sprocket 96 thereon. A chain 98 passes around small sprocket 96 and a large sprocket 100 . An idler sprocket 102 is suspended by a hangar 104 from a plate 106 extending between the long rails 60 and 62 . Large sprocket 100 is driven by chain 98 and a shaft 108 connects the center of the sprocket through a coupling 110 to a shaft 112 . Shaft 112 is fixed to and projects downwardly from a plate 114 that is welded or otherwise affixed to a plate 116 fixed beneath the bed 12 of the trailer 10 .
[0028] Shaft 112 projects downwardly through a hole 118 provided therefore through a steel plate 120 that is fixed to long rails 60 and 62 . Thrust bearings 122 have housings welded, or otherwise affixed to steel plate 120 . The thrust bearings are equidistant from the shaft 112 and are on a circle surrounding the shaft 112 .
[0029] Plate 116 rests on the balls of the thrust bearings and when the bed 12 is turned the plate 114 turns on the bearings.
[0030] Operation of motor 90 turns small sprocket 96 and drives chain 98 to turn large sprocket 100 and through shafts 108 and 112 and plate 114 , bed 12 of the trailer. Motor 90 is a DC motor, powered by the battery of the tow vehicle. Wires 124 , connected to motor 90 and to a connector 126 allow the motor to be coupled to the tow vehicle. A switch 126 is also connected in the wires 124 to allow the motor to be turned on and off. Switch 124 is preferable mounted on tongue 50 , but it will be apparent that the switch could be mounted elsewhere.
[0031] A locking plate 130 is pivotally connected at 132 to front rail 52 of undercarriage 54 and hangs from the pivot connection. A handle 134 projects from locking plate 130 and is used to pivot the locking plate to a position where a portion 136 of the locking plate overlaps the front edge 20 of bed 12 to prevent rotation of the bed. A pin 138 is inserted through aligned holes in the front rail and the locking plate. A small spring clip) 140 through the end of pin 138 holds pin 138 in place to prevent undesired turning of the trailer bed 12 .
[0032] With the rotating bed 12 trailer 10 can be conveniently used to load and unload snowmobiles, or all terrain vehicles, at any desired angle with respect to the trailer undercarriage. The bed is merely turned to the desired angle with respect to the fixed undercarriage and the ramp 42 is lowered to permit the vehicle to be driven onto the trailer bed. After loading the bed 12 ramp 42 is again pivoted to its raised and locked position and the bed is rotated to be aligned with and locked relative to the undercarriage. The, bed is turned to a desired angle relative to the undercarriage and ramp 40 ) is lowered to permit the vehicles to be driven from the bed 12 . Ramp 41 ) is then raised and locked in place.
[0033] Although a preferred embodiment of my invention has been herein disclosed, it is to be understood that the present disclosure is by way of example and that variations are possible without departing from the subject matter coming within the scope of the following claims, which subject matter I regard as my invention. | A trailer for transporting snowmobiles, all terrain vehicles and other vehicles that are driven onto the trailer and that includes a trailer bed onto which the vehicles are driven, a wheel supported undercarriage beneath the bed, a motor powered drive assembly to fully rotate the bed with respect to the undercarriage and protector/ramps at opposite ends of the trailer bed to provide ramps for driving vehicles on to and off of the trailer bed. | 1 |
TECHNICAL FIELD
This invention relates to assembling an electronic device attached to a sheet via a plurality of leads. More particularly during the assembly of the device, this invention relates to forming each of a plurality of leads into a given configuration while maintaining desired spacings therebetween.
BACKGROUND OF THE INVENTION
In the assembly of electronic devices, integrated circuit chips are enclosed alone or with other devices in a package having a plurality of leads extending therefrom. The industry seems trending toward an increasing number of such leads while the packages are being kept as small as possible to conserve space in service. Consequently, leads are becoming more densely arranged and adapting them for service connection has become a significant problem.
One method of providing densely arranged leads for assembling such an electronic device is to employ a carrier tape preferably made of conductive material. The leads are conventionally formed therein in clusters by photolithography and etching. The tape is indexed for bonding a chip and/or other device to the lead clusters and often a second bonding takes place to stiff leads in another lead frame, such stiff leads being insertable into a P-C board.
The packaging of an assembled device in protective material also typically takes place while an assembled device is still in a lead frame. Thereafter, each device is separately detached from the lead frame environment and leads are usually bent, shaped or otherwise adapted for service connection.
In one popular, lineally leaded package, the leads are aligned in two rows causing the device to be referred to as a dual inline package (DIP). With an increasing number of leads now being used, a problem with a DIP package is that it tends to become so long that service space is used inefficiently.
In another scheme, the leads are arranged in four rows extending from four sides of a typically square package sometimes referred to as a "Mini-Quad." Now the number of leads in a Mini-Quad range up to about 60 or 70 and heavier tape material is used without a second bonding to make leads which are adapted for surface mounting on a substrate. It will be appreciated that detaching such a package from a tape and adapting such a dense arrangement of leads for service while maintaining isolative spacings therebetween is a difficult task.
SUMMARY OF THE INVENTION
In view of the foregoing, it is an object of this invention to provide new and improved methods and apparatus for assembling an electronic device. Another object is to assemble an electronic device attached to a sheet via a plurality of leads. A further object during the assembly of such device, is to form each of a plurality of leads into a given configuration while maintaining desired spacings therebetween.
With these and other objects in mind, the present invention includes detaching from the sheet the device with the leads attached thereto and to at least one sheet member interconnecting the leads for maintaining desired spacings therebetween. The leads are formed into a given configuration while the interconnecting member is still attached. Such member is then trimmed from the leads to electrically isolate the leads from each other while maintaining the desired spacings therebetween.
In a preferred embodiment, the sheet is a carrier tape having clusters of finger-like leads formed therein. Each lead has a first end affixed to the tape and a second end extending toward the center of the cluster and being affixed to the electronic device.
In a further embodiment, there are at least two opposing rows of leads along at least two opposing edges of a device. The forming provides L-configurations in the leads such that when the device is placed upon a planar surface, all leads make substantially simultaneous contact with such surface.
BRIEF DESCRIPTION OF THE DRAWING
The above-described and other objects, advantages and features of the invention will be more easily understood from the following detailed description when read in conjunction with the accompanying drawing, wherein:
FIG. 1 is a plan view of a carrier tape suitable for practicing the instant invention.
FIG. 2 is a plan view of an electronic device assembled in a mini-quad package in accordance with the instant invention.
FIG. 3 is an elevational view, with a portion partially cut away, of the packaged device shown in FIG. 2.
FIG. 4 is a cross sectional view of a punch and die set in a first stage for detaching a device from a tape according to the instant invention.
FIG. 5 illustrates a second stage in operation of the set shown in FIG. 4.
FIG. 6 illustrates a third stage in operation of the set shown in FIG. 4.
It can be seen that some elements in the figures are abbreviated or simplified to highlight certain features of the invention. Also, where appropriate, reference numerals have been repeated in the figures to designate the same or corresponding features in the drawing.
DETAILED DESCRIPTION
The Packaged Device
In each of FIGS. 1-6, there appears at least one packaged device designated generally by the numeral 10 which is assembled in accordance with the instant invention. Device 10 typically includes a chip (not shown) embodying an integrated circuit. Alternately, device 10 may include an electronic circuit on a ceramic substrate or other component requiring the protection of a package and electrical connection to the outside world.
In the illustrative example, device 10 includes a plurality of leads 12 extending from a body 14 which includes a molded plastic material encapsulating a circuit component (not shown) and the inner ends of the leads 12. As best seen in FIG. 3, the leads 12 are formed in an L-configuration such that all leads make substantially simultaneous contact with a planar surface. Note also that body 14 is supported above such surface a predetermined distance, e.g., about 0.015 inches, to permit a cleaning solution to flow between the body 14 and a service substrate. At each corner of the body 14 a bumper 16 protrudes away from body 14 a sufficient distance to protect the leads 12 from damage in handling. A typical packaged device 10 is more fully described in U.S. Pat. No. 4,331,831 issued May 25, 1982 to A. J. Ingram et al, based on patent application Ser. No. 210,776, filed Nov. 28, 1980, assigned to Bell Telephone Laboratories, Incorporated.
Carrier Tape
FIG. 1 illustrates at least two frames 17 and 19 of a carrier tape 20 which is suitable for assembling devices in the practice of the instant invention. Tape 20 is about 19 m.m. wide to accommodate idler and sprocket wheels analogous to those typically used to drive motion picture films. Accordingly, such wheels are used to guide and drive tape 20 in the direction of arrow 21 for assembling devices 10 therewith.
Tape 20 is preferably made from conductive sheet material such as copper which is from about 1 to about 4 mils in thickness and may be designated CDA-102 OFHC by the Copper Development Association. Where only the tape material provides the leads 12 for service connection, the metal may be hardened to obtain spring temper.
Leading frame 17 illustrates a condition in tape 20 when a device 10 is detached therefrom and trailing frame 19 illustrates a condition when a device 10 is ready to be detached. Note in frame 19, that the leads 12 are typically provided in clusters 22 which may, for example, be spaced about 0.75 inches along the length of tape 20. Each cluster 22 typically includes sprocket perforations 24 for indexing the tape 20 in a lengthwise direction. A cluster 22 also includes finger-like leads 12, each having a first end affixed to the tape 20 and a second end (not shown) extending toward the center where said second end is affixed to a circuit within the device 10. In the example shown, the leads 12 are disposed in rows along the edges of device 10 and each row has a sheet member 28 extending to an inside frame edge 30 to interconnect the leads 12 when they are detached from the tape 20.
It will be appreciated that the interconnecting members 28 perform an important function in the practice of the invention. In the illustrative example the leads 12 are about 8 mils wide with a space of about 8 mils between each lead. Without some expedient to maintain such spacings, the leads 12 tend to become disorganized as device 10 is detached from tape 20 and the leads 12 are formed and trimmed.
Tape 20 is indexed in cycles and each frame is stopped at various stations for chip bonding, packaging and similar functions. FIG. 1 illustrates a frame 17 which remains after a device 10 is detached according to an arrow 31.
Method of Assembly
In a method of practicing the invention there are essentially three steps performed seriatim upon device 10 and its cluster 22 of leads 12 between FIG. 1 and FIGS. 2 or 3. In each step a separate function is performed and each such function is preferably performed substantially simultaneously upon all leads 12 in a cluster 12. For example, in the first step all leads 12 in a cluster 22 are severed along frame edge 30 such that the device 10, the four rows of leads 12 and four interconnecting members 28 are detached from frame 17. While members 28 remain advantageously attached to the rows of leads 12 in the second step, the leads are formed into the L-configuration best seen in FIG. 3. The four interconnecting members 28 are then severed from the leads 12 to finish the assembly of device 10.
Apparatus For Assembly
FIGS. 4-6 illustrate an apparatus designated generally by the numeral 33 which is presently preferred in practicing the method described above. Apparatus 33 includes the following items with the following general designations: a composite punch 34, a die 36 and a pedestal 38. Pedestal 38 includes a raised, four-sided frame 40 for supporting four edges of the body 14 of a device 10 and for providing four die surfaces in a frame 41 for forming L-configurations in the leads 12. Pedestal 38 also includes a four-sided framed cutting edge 43 to make a final cut upon the cluster 22 of leads 12. Pedestal 38 further includes a cavity 42 for collecting any dirt shed from a body 14 or a device 10.
Die 36 includes four members of which only member 44 and 46 are shown. Members 44 and 46 include edges 45 and 47, respectively, for making a first cut upon leads 12 in rows along left and right edges of the device 10 as shown in FIGS. 4-6. Members 44 and 46 also include flat surfaces 48 and 49, respectively, for supporting the leads 12. It will be appreciated that the unseen members of die 36 have similar edges and similar surfaces for cutting and supporting rows of leads 12 on front and back edges of the device 10.
The composite punch 34 includes four outside cutting members of which only 50 and 52 are shown in FIGS. 4-6. Punch 34 also includes four inside forming members of which only 54 and 56 are shown in FIGS. 4-6. Punch 34 further includes a central member 58 containing a bored duct 59 through which a vacuum can be drawn. It can be seen that members 50 and 54 act upon a row of leads 12 along the left edge of device 10 while members 52 and 56 work upon leads 12 along the right edge of said device. It will also be appreciated that two similar cutting members and two similar forming members work up on leads 12 along the front and back edges of the device 10, all according to FIGS. 4-6.
Each cutting member including 50 and 52 also has tapered pilot probes extending from the ends thereof to center the device 10 upon pedestal 38. Probes 51 and 53 shown in FIGS. 4-6 extend from an unseen cutting member which works upon leads 12 along the back edge of device 10. By reference to FIG. 1, it can be seen that there are tapered shoulders on each end of an interconnecting member 28 which shoulders are engaged by the pilot probes in centering device 10 on pedestal 38.
The operation of apparatus 33 proceeds essentially in three steps corresponding to the method steps previously described. A frame of tape 20, such as frame 19, is indexed into apparatus 33 whereupon punch 34 is lowered and pilot probes including 51 and 53 center a device 10 on pedestal 38. It can be seen in FIG. 4 that the left and right rows of leads 12 become disposed, respectively, upon surfaces 48 and 49 of die members 44 and 46, respectively. In a further lowering of punch 34, the four cutting members including 50 and 52 engage the leads 12 upon four respective die cutting edges including 45 and 57. Device 10, including the interconnecting members 28, are detached from tape 20, but members 28 remain attached to the leads 12.
In a further lowering of punch 34 as seen in FIG. 5 the four forming members including 54 and 56 engage the leads 12 along the four sides of body 14. Such leads 12, with the interconnecting members 28 attached thereto, are driven into the four die forming surfaces in frame 41 on pedestal 38. Note up to this point, that all parts of punch 34 have moved together and that central member 58 with vacuum duct 59 has now contacted the body 14 of device 10.
In the last step, as shown in FIG. 6, only the four cutting members including 50 and 52 continue lowering and the formed leads 12 are engaged by inside edges of the cutting members including 50 and 52 upon the cutting edges of frame 43 on pedestal 38. In this manner, the interconnecting members 28 are then detached from the leads 12 and each member 28 falls away as shown.
It is incidentally noted in FIG. 6 that a vacuum is drawn through conduit 59 of member 58 such that when punch 34 is subsequently raised a completed device 10 is lifted from pedestal 38. A track (not shown) is then inserted within apparatus 33, device 10 is released upon the track and the track is withdrawn.
Alternate Embodiments
It will be apparent to one of ordinary skill in the art that it is not necessary to employ a monolithic web such as tape 20 in practicing the invention. For example, a composite web of material including a plastic substrate with clusters of conductive leads formed thereon could as well be used to assemble a device 10. Further, it is evident that a broad sheet of material such as copper could be used with parallel rows of lead clusters 22 formed therein for such assembly.
Although the invention is described with respect to a packaged device 10 haveing four rows of leads 12 extending therefrom, it is within the spirit of the invention to use interconnecting members 28 on practically any number of rows of leads 12. Moreover, device 10 need not be packaged but could, for example, be a chip or a miniceramic substrate carrying circuitry.
It is also apparent that other punch and die sets could be used to perform the three functions performed by apparatus 33. For example, after the forming step in FIG. 5, the pedestal 38 could be lowered against other cutting edges (not shown) to detach the interconnecting members 28. In such a case, cutting and forming members such as 50 and 54 could be combined into one member.
There have been disclosed herein certain embodiments of the invention and applications thereof. Nevertheless, it is to be understood that various and sundry modifications and refinements may be made and used which differ from that disclosed without departing from the spirit and scope of the instant invention. | An electronic device (10) is attached to a carrier tape (20) by a cluster (22) of leads (12) which are closely spaced relative to each other. The device (10) is detached from tape (20) along with the leads (12) and tape members (28) interconnecting such leads (12) for maintaining the spacings therebetween. The leads (12) are formed with a given configuration while the members (28) are still attached. Such members (28) are then trimmed from the leads (12) to electrically isolate such leads (12) while still maintaining the desired spacings therebetween. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Application No. 61/614,100 filed Mar. 22, 2012, which is incorporated by reference herein.
TECHNICAL FIELD AND BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to the field of aircraft passenger seat accessories and, more particularly, to foldable lap table with a large tabletop that can be readily deployed and stowed away as needed with a simple opening and closing motion.
[0003] Aircraft passenger seats and suites typically include a variety of accessories for passenger use and convenience. Some of these accessories are fixed in position and are ready for use, some are permanently attached to other surfaces and move between deployed and stowed positions, and others are free from attachment and must be stowed in compartments when not being used. It is with respect to this third type of accessory that this particular invention finds application.
[0004] Aircraft passengers typically require some form of tabletop surface for working and dining. While coach class aircraft passenger seats typically include a tray table deployable from a stowed position attached to the back of a forward positioned seat or attached to the side of the seat, tray tables associated with suite style seats are often inconvenient to position in certain seating configurations or are not comfortable for use in all seating positions. For example, a deployable tray table permanently mounted within an aircraft passenger suite may not achieve a convenient or comfortable use position for a passenger in a lie flat seating position, such as with a bed. Whereas a tray table might work when the suite is configured as a seating arrangement, it may not work when the suite is configured as a bed. Similarly, an attached table for use in an aircraft bed configuration would not work when the suite is reconfigured as a seating arrangement. Additionally, as some aircraft passenger suites may include both a work/dining chair and a passenger seat, an attached tray table may not be conducive to both work dining chair use and passenger seat use.
[0005] Further, it is typical for tabletops and tray tables located in aircraft passenger cabins to serve many functions. Aircraft passengers may use tray tables for food and beverages, reading and writing, seating electronic devices, playing cards and games, etc. Any and all such tasks are carried out in an environment with extreme space and weight constraints, and where bumps, jostles and turbulence are commonplace.
[0006] Accordingly, there is a need for a table that is not required to be tied and affixed to an aircraft passenger seat, seat back, arm, cabin, fuselage or any other fixture of the aircraft. There is also a need for an aircraft passenger table that is easily and efficiently stowed and that is lightweight. Further, there is a need for a tabletop suitable for a variety of different tasks and that functions well in the turbulent nature of aircraft travel.
SUMMARY OF THE INVENTION
[0007] It is therefore an object of the present invention to provide an aircraft passenger auxiliary table surface that is free from attachment for use in any seating, resting or reclining position or in any other position within the aircraft.
[0008] It is a further object of the invention to provide an aircraft passenger table that can be readily and easily deployed and stowed as needed.
[0009] It is a further object of the invention to provide an aircraft passenger table having a thin profile and of lightweight construction so as not to require extra stowage space or weight in a tight aircraft interior.
[0010] It is a further object of the invention to provide an aircraft passenger table that facilitates writing and drafting, dining, laptop computer use, and other uses common on passenger aircraft.
[0011] These and other objects and advantages of the invention are achieved by providing a foldable aircraft passenger table designed to facilitate large tabletop space that can be readily deployed and stowed away as needed with a simple opening and closing motion. One side of the foldable aircraft passenger table has a surface that resists skidding of implements placed on the table, such as dining articles when a passenger is dining. Such a surface may prevent articles from sliding during aircraft turbulence. The other, opposite, side of the foldable aircraft passenger table has a surface that is smooth, rigid and depression resistant to facilitate writing, drafting and other such activities. The table is divided into a plurality of sections or table leaves.
[0012] According to one embodiment of the invention, a foldable lap table is provided that operates in a folded and an unfolded configuration. The lap table has a first table leaf joined along a first hinge to a second table leaf. The first hinge folds in a first direction. The lap table also has a third table leaf joined along a second hinge to a fourth table leaf. This second hinge is a linear extension of the first hinge. The second hinge folds in a second direction opposite in direction from the first direction when the lap table is in the unfolded position. The third table leaf and the fourth table leaf collectively define a triangular shape. The third table leaf is also joined to the first table leaf along a third hinge and the fourth table leaf is also joined to the second table leaf along a fourth hinge. The respective hinges and leaves are configured to permit unison movement such that the third and fourth table leaves are hidden between the first and second table leaves in the folded position and are exposed in the unfolded position.
[0013] According to another embodiment of the invention, the first, second, third and fourth hinges may be each living hinges.
[0014] According to another embodiment of the invention, the first, second, third and fourth table leaves may each include a plurality of layers. One of the plurality of layers may be a top layer that is contiguous among each of the leaves and includes the first, second, third and fourth living hinges.
[0015] According to another embodiment of the invention, the second table leaf may be a mirror image of the first table leaf and the fourth table leaf may be a mirror image of the third table leaf.
[0016] According to another embodiment of the invention, the plurality of layers may include an intermediate layer adhered to the top layer and a bottom layer adhered to the intermediate layer. The intermediate layer or the bottom layer of any one of the first, second, third or fourth table leaves may not be attached to the intermediate layer or the bottom layer of another leaf.
[0017] According to another embodiment of the invention, the top layer may be made from a flexible material that is bend-fatigue resistant and skid resistant. The bottom layer may be made from a smooth material that is depression resistant or has a self-leveling material. The bottom layer may be rigid to support a laptop or tablet and optionally may conduct heat. In a specific example, the top layer may be made of rubber or felt and the bottom layer may be made of rigid plastic or lightweight metal.
[0018] According to another embodiment of the invention, the first and second table leaves and the third and fourth table leaves together form a generally planar tabletop when the foldable lap table is in the unfolded position. In such an embodiment, the first or second table leaves form a reversible smaller table top having a surface area less than half of the generally planar table top of the unfolded position when the foldable lap table is in the folded position.
[0019] According to another embodiment of the invention, the foldable lap table in the folded position may fit within and is stowable within a typical commercial airline seat pocket.
[0020] According to another embodiment of the invention, the foldable lap table in the unfolded position may include four rounded corners. The foldable lap table in the folded position may include three rounded corners.
[0021] According to another embodiment of the invention, the foldable lap table in the unfolded position may include four rounded exposed corners having an arc of approximately 90 degrees and the table in the folded position may include three rounded exposed corners having an arc of approximately 90 degrees.
[0022] According to another embodiment of the invention, the lap table includes a plurality of leaves connected together by a plurality of living hinges. Each one of the leaves includes a top layer made of a flexible, fatigue and skid resistant material for supporting objects during aircraft turbulence and a bottom layer made of a smooth depression resistant material for writing. In this embodiment, the top layer forms the living hinges and the bottom layer of each one of the plurality of leaves is either independent from the bottom layer of the other leaves or does not affect the operation of the living hinge of the top layer. An exposed surface area of the foldable lap table in the folded position is less than one half the size of the exposed surface area of the foldable lap table in the unfolded position.
[0023] According to another embodiment of the invention, at least two discrete leaves of the plurality of leaves are mirror images of two other discrete leaves of the plurality of leaves, and the foldable lap table is sized to fit in the lap of a typical passenger in either the folded or unfolded position and also sized to be stowable within a typical commercial airline seat pocket.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0024] The present invention is best understood when the following detailed description of the invention is read with reference to the accompanying drawings, in which:
[0025] FIG. 1 is a top perspective view of the foldable aircraft passenger table in the folded position;
[0026] FIG. 2 is a top perspective view of the foldable aircraft passenger table shown in a partially unfolded position;
[0027] FIG. 3 is a top perspective view of the foldable aircraft passenger table shown in a partially unfolded position;
[0028] FIG. 4 is a top perspective view of the foldable aircraft passenger table shown in a substantially unfolded position;
[0029] FIG. 5 is a close up perspective view of the layers and a living hinge of the foldable aircraft passenger table; and
[0030] FIG. 6 is a rear perspective view of the foldable aircraft passenger table shown in a substantially unfolded position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] Referring now specifically to the drawings, a foldable aircraft passenger lap table is shown generally at reference numeral 10 . The foldable lap table operates from a folded position as shown in FIG. 1 to partially unfolded positions as shown in FIGS. 2 and 3 to a substantially unfolded position as shown in FIGS. 4 and 6 . The foldable aircraft passenger table 10 may be easily unfolded for use and folded for stowage when not in use.
[0032] Referring to FIG. 4 , the foldable lap table 10 includes a first leaf 20 , a second leaf 30 , a third leaf 40 and a fourth leaf 50 . The third leaf 40 and the fourth leaf 50 are generally triangular in shape. The foldable lap table 10 also includes a first living hinge 60 , a second living hinge 62 , a third living hinge 64 and a fourth living hinge 66 . The first living hinge 60 is located between the first table leaf 20 and the second table leaf 30 . The first living hinge 60 forms the link between the first table leaf 20 and the second table leaf 30 . The second living hinge 62 is located between the third table leaf 40 and the fourth table leaf 50 . The second living hinge 62 forms the link between the third table leaf 40 and the fourth table leaf 50 . The second living hinge 62 is a linear extension of the first living hinge 60 when the foldable lap table 10 is in the unfolded position as shown in FIGS. 4 and 5 . When the foldable lap table 10 is in the folded position as in FIG. 1 , the second living hinge 62 rotates in a direction opposite from the first living hinge 60 .
[0033] The third living hinge 64 of the foldable lap table 10 is located between the first table leaf 20 and the third table leaf 40 . The third living hinge 64 forms the link between the first table leaf 20 and the third table leaf 40 . The third living hinge 64 is located at an acute angle to the second living hinge 62 when the foldable lap table 10 is in the unfolded position.
[0034] The fourth living hinge 66 of the foldable lap table 10 is located between the second table leaf 30 and the fourth table leaf 50 . The fourth living hinge 66 forms the link between the second table leaf 30 and the fourth table leaf 50 . The fourth living hinge 66 is located at an acute angle to the second living hinge 62 when the foldable lap table 10 is in the unfolded position.
[0035] When the foldable lap table 10 is in the unfolded position as shown in FIGS, 4 and 6 , the second table leaf 30 is a mirror image of the first table leaf 20 . Likewise, the fourth table leaf 50 is a mirror image of the third table leaf 40 . In the unfolded position, the foldable lap table 10 has four rounded corners 80 , 82 , 84 and 86 , each one of the corners having an arc of approximately 90 degrees.
[0036] Each of the first table leaf 20 , the second table leaf 30 , the third table leaf 40 and the fourth table leaf 50 is made of a plurality of layers as best shown in FIG. 5 . The top surface layer 70 is contiguous among all of the leaves 20 , 30 , 40 and 50 and forms the material of each of the first living hinge 60 , second living hinge 62 , third living hinge 64 , and fourth living hinge 66 . Preferably, the top surface layer 70 is made of a material that is bend-fatigue resistant and is also skid resistant such as rubber or thermoplastic polymer. The top layer may also be felt. The top surface layer 70 is concealed when the foldable lap table is in the folded position as in FIG. 1 and is exposed for use when the foldable lap table 10 is in the unfolded position as in FIG. 4 . The bottom surface layer 72 , unlike the top surface layer 70 , may not be continuous among the first table leaf 20 , the second table leaf 30 , the third table leaf 40 and the fourth table leaf 50 . That is, the bottom surface layer 72 of the first table leaf 20 may not touch and may be separate from the bottom surface layer 72 of the other leaves. The bottom surface layer 72 of the second table leaf 20 may not touch and may be separate from the bottom surface layer 72 of the other leaves. The bottom surface layer 72 of the third table leaf 40 may not touch and may be separate from the bottom surface layer 72 of the other leaves. The bottom surface layer 72 of the fourth table leaf 50 may not touch and may be separate from the bottom surface layer 72 of the other leaves. Thus, the bottom surface layer 72 may not form any portion of any of the respective living hinges 60 , 62 , 64 , or 66 . The bottom surface layer 72 is exposed in the fold position as shown in FIG. 1 and is also exposed in the unfolded position as shown in FIG. 6 . The bottom surface layer 72 may be smooth, depression resistant, and rigid to permit and support writing thereon. The bottom surface layer 72 may also be made of a material that conducts heat away from objects placed thereon. The bottom surface 72 may be made of a rigid plastic, of a metal, or of another material. One or both of the top and bottom surfaces may be made from self-leveling or “self-healing” material. In an alternative embodiment, the bottom surface layer 72 is contiguous among the leaves and does not interfere with the hinge functionality of the top surface layer 70 .
[0037] In some embodiments, an intermediate layer 74 , as shown in FIG. 5 , is located between the top surface layer 70 and the bottom surface layer 72 . In such an embodiment, the top surface layer 70 is adhered or otherwise attached to the intermediate layer 74 and the bottom surface layer 72 is also adhered or otherwise attached, on an opposite from the top surface layer 70 , to the intermediate layer 74 . In embodiments without an intermediate layer 74 , the top surface layer 70 is adhered or otherwise attached to the bottom surface layer 72 . The intermediate layer 74 may be made of the same material as the top surface layer 70 , of the same material as the bottom surface layer 72 , or of another material.
[0038] When the foldable lap table 10 is in the folded position as shown in FIG. 1 , the rigid surface of the bottom surface layer 72 is exposed on both sides of the foldable lap table 10 so that the passenger may use either side to bear down on and to write upon. In the folded position as shown in FIG. 1 , the foldable lap table 10 has three rounded corners, 90 , 92 and 96 , each having an arc of approximately 90 degrees. In the folded position, the portion of the exposed surface area useful at any one time is less than one half of the portion of the exposed surface area useful at any one time when in the unfolded position. Thus, if a passenger wishes to write and to bear down on the bottom surface 72 , he may do so in either the folded position of FIG. 1 or the unfolded position of FIG. 6 . That is, if the passenger's writing area requirements are small, he may use bottom surface 72 of the foldable lap table 10 in the folded position shown in FIG. 1 . Conversely, if the passenger requires mores space upon which to bear down and write, he may use the bottom surface 72 of the foldable lap table 10 in the unfolded position as shown in FIG. 6 . On the other hand, if the passenger desires to dine or to place articles on the foldable lap table 10 and reduce the chance that the articles would slide or move as a result of turbulence, the passenger may use the top surface 70 of the foldable lap table 10 in the unfolded position as shown in FIG. 4 .
[0039] The foldable lap table 10 is thus designed to facilitate large tabletop space that can be easily deployed and stowed away as needed with a simple opening and closing motion. The thin profile of the foldable lap table 10 does not require extra stowage space in tight aircraft interiors. Referring to FIGS. 2 and 3 , the foldable lap table 10 affords easy opening and closing action via the living hinges 60 , 62 , 64 and 66 . In this hinged manner, the third and fourth table leaves 40 , 50 are able to simultaneously fold inward as the first and second table leaves 20 , 30 are brought together when the foldable lap table 10 is being folded for stowage.
[0040] Opening and closing of the foldable lap table 10 is accomplished with one hand with a simple lifting motion to separate the faces of the top surface layer 70 of the first table leaf 20 and second table leaf 30 that make up the majority of the surface area of the foldable lap table 10 in the unfolded position. Closing the foldable lap table 10 can be accomplished using one hand to bring the top faces of top surface layers 70 of the first table leaf 20 and second table leaf 30 together.
[0041] Referring to FIG. 3 , the foldable aircraft passenger table 10 is shown about halfway open, revealing the third and fourth table leaves 40 , 50 that had been concealed by the first and second table leaves 20 , 30 when the foldable lap table 10 was fully folded as in FIG. 1 . The third and fourth table leaves 40 , 50 overlap one another when the foldable lap table 10 is in the folded position. The third and fourth table leaves 40 , 50 make up a lesser portion of the total surface area of the foldable lap table 10 when in the unfolded position of FIGS. 4 and 6 . When the foldable lap table 10 is in the folded position, the third and fourth table leaves 40 , 50 fold against the respective first and second table leaves 20 , 30 such that they are trapped between the first and second table leaves 20 , 30 and the foldable lap table 10 surface area is smaller than its unfolded size.
[0042] A foldable aircraft passenger lap table according to the invention has been described with reference to specific embodiments and examples. Various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description of the preferred embodiments of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation, the invention being defined by the claims. | A foldable lap table including a first table leaf joined along a first hinge to a second table leaf, the first hinge folding in a first direction, and a third table leaf joined along a second hinge to a fourth table leaf, the second hinge being a linear extension of the first hinge and folding in a second direction opposite the first, wherein the third table leaf is further joined to the first table leaf along a third hinge and the fourth table leaf is further joined to the second table leaf along a fourth hinge such that the respective hinges and leaves are arranged to permit unison movement of the leaves when the lap table is folded and unfolded. | 1 |
FIELD OF THE INVENTION
This application relates in general to turbomachinery and in particular to an improved method of characterizing blade vibration resonances in one or more rows of rotating blades of a turbomachine.
BACKGROUND OF THE INVENTION
In high speed turbomachines, e.g. steam or gas turbines, multiple turbine stages, each comprising a plurality of circumferentially distributed blades forming a turbine wheel, are arranged axially along a rotatable shaft. The turbine wheels rotate in response to the force of a high pressure fluid flowing axially through the machine and impinging on the blades of the wheels. Natural resonant frequencies of the blades may coincide with or be excited by some rotational speeds and integral harmonics thereof. Blade resonances excited at multiples of the shaft rotational frequency may create stresses which break one or more blades and cause extensive damage, thus shutting the machine down and requiring extensive repair.
To avoid resonances, blades in the low pressure sections of steam turbines are tuned to avoid excitation at multiples of operating speed. This tuning is achieved by careful analysis during blade design. Detailed testing is performed prior to operation of a machine to ensure that new blades do not resonate during normal operation. A rotating test of a row of turbine blades comprises excitation of the blades with a fluid jet while measuring the vibratory response of several blades with strain gages to determine the frequencies of resonance, that is the excitation frequencies at which the greatest response occurs. Such a steady fluid jet excites only frequencies which are integral multiples of shaft rotational speed. The shaft speed must be varied in order to vary the excitation frequency. Stringent quality control practices are then followed to assure that the blades are manufactured as designed. These quality control measures depend upon laboratory testing to set manufacturing tolerances and to verify blade tuning. However, because individual evaluation of manufactured blades can be time intensive, it has not been practical to laboratory test all blades under normal rotating conditions in order to confirm proper blade tuning. On the other hand, blade testing in non-operational environments has been an imperfect alternative because it requires correction of test data in order to predict vibratory responses under rotating conditions. These adjustments are necessary because resonant frequencies vary with changes in blade stress resulting from centripetal forces during operation.
It is also desirable to monitor rotating blades during operation in order to identify vibration problems which develop after a turbomachine is put into use. This on-line evaluation is necessary in part because evaluations performed prior to actual use, even rotational tests, do not subject the blades to the same forces, temperatures and pressure conditions which are experienced during field operations.
Continuous monitoring of blade vibrations is also important in order to detect shifts in resonant frequencies which signal structural changes. For example, a propagating crack will cause the resonant frequencies of a blade to decrease. It is desirable to detect these changes before the blade becomes resonant at the shaft rotational speed or a harmonic thereof. Otherwise the vibrating blade may undergo dangerously high stresses. Other factors also cause resonant frequencies of the blades to change with time. For example, corrosion and erosion of airfoil areas may also change resonant frequencies and changes in riveted or welded joints by which some blading assemblies are fastened together and to the turbine shaft may alter resonant frequencies.
The model frequencies of rotating blades also depend on the fit of blades in the rotor attachment grooves which secure the blades in place. The dynamic effect of high speed rotation normally improves the securement of a blade because centripetal forces tighten the connection. This dynamic loading at operating speed is difficult to simulate. The frequency response of a blade is a strong function of operating speed, because centripetal forces both stiffen the blades and enforce their connection to the rotor. The resulting variation of resonant frequency with speed must be determined if stationary test data are used.
Although stationary testing in combination with appropriate correction data can provide meaningful information for new blades, corrosion in the rotor attachment grooves is known to affect blade securement and change both the stiffness of a blade and its damping characteristics. Thus, factory test data do not necessarily correspond to the characteristics of blades found in older machinery. Furthermore, similar adjustments to stationary test data may not result in the correct dynamic characteristics of retrofit blades, again because age effects alter the original tolerances in rotor attachment grooves. These variable physical changes cannot be fully accounted for without direct measurements.
Although previous methods of performing evaluations have successfully eliminated some serious vibration problems, it is desirable to perform reliable and comprehensive monitoring in order to further avoid the above described problems. In the past there has been a very limited capability for monitoring on-line blade vibrations, but with recent advances in blade vibration monitoring, fast, long-lived and cost-effective monitoring systems are now able to provide and continuously update blade vibration information for entire rows of blades in turbomachines. An exemplary system is disclosed in U.S. Pat. No. 4,573,358 assigned to the assignee of the present invention.
With the advent of improved systems for blade vibration monitoring it is desirable to periodically measure blade resonances in operating equipment in order to detect structural changes. In the past this has not been possible because on-line monitoring of blade vibrations has been limited to passive evaluations, i.e., to the detection of naturally occurring resonances which correspond to the frequency of shaft rotation or harmonics thereof. A disadvantage of passive evaluation is, of course, that the shifts in resonant frequencies which signal structural defects may not be discoverable before extensive damage results. One reason that shifts in blade resonances are not monitored on-line is that there has not been available a method for exciting the blades of a turbomachine at variable frequencies during normal operation. Clearly such a method in combination with a suitable blade vibration monitoring system would provide reliable and accurate data acquired under the most realistic conditions.
SUMMARY OF THE INVENTION
Among the several objects of the invention may be noted the provision of a system for exciting rotating blades of a turbomachine with selectable vibration frequencies, a method for operating a system for exciting rotating blades of a turbomachine with selectable vibration frequencies and an improved method for characterizing the frequencies of resonant vibration in a plurality of rotating blades in a turbomachine which overcomes the above discussed disadvantages, limitations or undesirable features, as well as others, of the prior art; the provision of such system and method for exciting rotating blades with vibrations which, when used in combination with other equipment such as a blade vibration monitoring system, provides for a comprehensive measurement, diagnosis and detection of blade vibration problems not heretofore available; the provision of such a system and method in which both synchronous and nonsynchronous blade vibration frequencies can be selectively excited in a safe and controllable manner while the turbo-machine operates at synchronous speed, such system and method allowing for the measurement and assessment of frequency shifts and amplitude changes in characteristic blade resonances which may be caused by cracking, thermal gradients, material changes, deposits, corrosion and other factors; the provision of such a system and method which simplify and increase the speed and accuracy of tests for characterizing the resonant responses of turbomachine blades; and the provision of such a system and method which reduce the number of blade vibration sensors needed to monitor a rotating blade row. These as well as other objects and advantageous features of the present invention will be in part apparent and in part pointed out hereinafter.
In general, a system in one form of the invention is provided with a plurality of controllable fluid jets, positioned about a blade row or turbine wheel in a turbo-machine, from which a fluid can be selectively directed onto the rotating blades for exciting the blades at selectable vibration frequencies in order to identify blade resonances.
Also in general, a method is provided in one form of the invention for exciting rotating blades at various vibration frequencies in order to induce resonant vibrations.
Further in general, a method is provided for performing a comprehensive characterization of blade resonant frequencies in a plurality of rotating blades. The method evaluates resonances by exciting the blades at non-integer as well as integer multiples of synchronous turbine speed and may be used to evaluate resonant frequencies at any desired resolution. The method allows for testing all the rotating blades in a blade row of an operating turbomachine at synchronous speed thus providing a means for evaluating installed blades in new machinery and older machinery under normal operating conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified schematic illustration of a turbine cross-section showing a relative arrangement of one embodiment of the inventive programmable controllable fluid jet blade excitation system;
FIG. 2 is a partial cross-section of a steam turbine illustrating the arrangement of a programmable fluid jet relative to a blade row;
FIGS. 3 through 7 illustrate timing diagrams for operation of the fluid jets relative to a blade for initiating various excitation frequencies; and
FIG. 8 contains a table of selected blade vibration frequencies and harmonics thereof which can be induced by one embodiment of the inventive system and method.
DETAILED DESCRIPTION
The inventive methods and apparatus are described by way of example with particular application to the vibratory excitation of a row of blades in a steam turbine, but it is to be understood that the inventions are suitable for evaluation of bladed turbomachines generally.
Referring to FIG. 1, there is illustrated a schematic of the inventive programmable fluid jet blade excitation system coupled to a turbine 12. The system includes a plurality of controllable fluid jets 16 disposed about a cylindrically shaped turbine casing 35. Each jet 16 comprises an inlet supply line 24, an actuator 26 incorporating a controllable valve (not shown) for selectively blocking line 24 and an outlet nozzle 18 for directing fluid onto blades of the turbine. A high pressure steam supply (not shown) is coupled to each jet 16 through supply lines 24. Actuators 26 controllably open and close the valves internal to the jets in order to selectively direct a pressurized fluid stream through nozzles 18. Each jet is positioned about a turbine rotor disk 20 to which is attached a plurality of turbine blades forming a turbine wheel. For ease of understanding, only one blade 22 is illustrated and only three equally spaced jets 16 are shown. Blade excitation occurs by virtue of impact of the fluid from nozzles 18 against the rotating blade.
It is to be understood that while this illustrative jet arrangement may be used to simultaneously excite all of the blades in a row, still other jet arrangements may be used to successfully implement the inventive method. For example, a single jet may be used to excite the rotating blades at resonant frequencies, but because a blade would not receive excitation pulses more frequently than once per revolution the decay of blade vibration amplitude between excitations could make detection of resonant frequencies difficult. Nor is it necessary that the jets 16 be uniformly spaced in order to induce vibratory excitations at predetermined frequencies. In fact, unequal spacing of the jets may be desirable in applications where a complete circle of jets would be difficult or expensive to install.
The actuators 26 are controlled by a digital controller 28 of a type well known in the art such as, for example, a programmable controller. For a given arrangement of jets 16, appropriately phased timing signals may be programmed into digital controller 28 in order to induce desired vibratory excitation frequencies in blades 22 by contact between the blades and the fluid stream from the jets. Digital controller 28 selectively provides control signals along control lines 30 to each actuator 26 in order to selectively open and close the valve within the jet so that a fluid stream is "fired" at each blade to generate desired excitation frequencies. Controller 28 is synchronized with blade rotational velocity by a SYNC signal provided by a shaft speed sensor (not shown) of a type well known in the art. The arrangement of a controllable jet relative to a blade row is further described in FIG. 2 wherein a vibration sensor 40 is also illustrated adjacent the rotating blade row in order to detect blade vibrations induced by the jets.
FIG. 2 is a partial cross-section of a longitudinal section of a low pressure steam turbine 12 in which the present invention is applied. The turbine section includes a casing 35 surrounding and supporting a rotatable shaft 32 to which is attached a plurality of rows of blades 22. Each row of rotating blades is positioned adjacent a corresponding row of stationary blades 34, a row of blades and a row of stationary blades forming a turbine stage. Pressurized steam enters the turbine through an annular chamber 36 and is directed through the turbine stages. The stationary blades 34 effect the direction of steam flow onto blades 22. The present invention is shown in conjunction with the last two turbine stages to the right hand side of FIG. 2. The steam jet nozzle 18 passes through a support member 38 for stationary blades 34 and terminates adjacent a radially outer tip 23 of blade 22. The control actuator 26 and inlet 24 for the jets 16 are preferrably positioned outside turbine casing 35 and are not shown in FIG. 2. During turbine operation, the steam through the turbine stages reacts against blades 22 causing rotation of shaft 32. If an actuator 26 is energized to allow a high pressure steam pulse to be injected through nozzle 18, the rotating blade will impact against the steam pulse. The resulting vibration in the blade 22 can then be detected by sensor 40 which is attached to a nonrotating structural portion of the turbine adjacent the tip 23 of blade 22. The connections from sensor 40 to external of the turbine are well known and not shown. The sensor 40 may be any of a number of suitable sensors such as, for example, electromagnetic probes.
In a preferred embodiment, the controllable jets 16 are equally spaced in a circle about a blade row. In this embodiment, sequential and periodic firing of the three jets 16 occurs at a predetermined frequency referred to herein as the jet cycling speed. It should be noted that when a jet is "fired", the internal valve is opened so that a fluid stream is directed into the blade rotational path. Several consecutive blades may be excited by a continuous stream. The jet nozzles 18 may be oriented along turbine radius lines since the major force exerted on the blades is the impact with the fluid stream caused by the rotational velocity of the blades.
In the following description, J represents the apparent rotational velocity of the jets as a fraction of the speed and in the direction of blade rotation, i.e., by controlling the jet firing times, the jet appears to rotate. When the rotational velocity of a jet is the same as the blade rotational velocity, J =1; when jet rotation is counter to blade rotation, J is less than 0; and when jet rotation is in the direction of blade rotation, J is greater than O. By way of example, for R=60 hz and a jet cycling speed of 36 Hz, J=0.1. When implementing the method, controller 28 may be programmed to generate desired jet cycling speeds based on one or more selected values of J.
The vibratory frequencies F n which are excitable by the jets are given by
F.sub.n =nR(1-J),
where n is an integer and R is the turbine rotational frequency. F 0 is the steady, non-oscillatory component of the force. Fundamental vibratory frequencies F 1 correspond to n=1 and harmonics of F 1 occur for other values of n.
For example, when J=+0.25, completion of one jet cycling period will correspond to four revolutions of the rotor and F 1 =0.75R; F 2 =1.5R; F 3 =2.25R; F 4 =3.00R; F 5 =3.75R; F 6 =4.50R; etc. FIGS. 3, 4 and 5 are timing diagrams corresponding to F 1 , F 3 and F 6 respectively. FIGS. 6 and 7 illustrate blade response at values of F for which n is a non-integer, i.e., n=2.75 and n=3.50. Generally, in FIGS. 3-7, the upper three plots labeled Jet 1, Jet 2 and Jet 3 illustrate the on-off cycling of the jets 16 as their respective valves are opened and closed by controller 28 command signals. The next lower plot labeled "At Jet" in each figure indicates the time at which a single selected blade passes each jet. The plot labeled "VELOCITY" indicates the velocity response of the blade tip to the vibratory excitations induced by the fluid stream or fluid pulse from the jets. The plot labeled "POWER" indicates power input, i.e., energy transferred to the blade from each fluid pulse's impact with the blade as a function of time. In FIGS. 3-5 each power input coincides with a peak positive blade tip velocity indicating reinforcement of the blade excitation frequency. On the other hand, in FIGS. 6 and 7 some of the power inputs do not reinforce the blade excitation frequency, as indicated by inverted pulses in the power plots, but rather occur at times such that blade vibration energy is reduced.
FIG. 8 is a table of vibratory frequencies and harmonics thereof which may be generated based on various apparent jet rotational velocities. By monitoring blade vibration for sequential values of J, several overlapping series of F n may be inspected with a blade vibration monitor for resonant responses. While FIG. 8 illustrates the overlapping values of F n which may be had for a few values of J. In order to confidently resolve the center frequency of each blade resonance, J must be varied in small incremental steps. For example, it has been found that sufficient resolution will be had in order to identify the center frequency of every resonance above the fifth harmonic if J is varied from -0.1 to +0.1 of rotor speed in incremental steps of 0.1 percent speed.
Thus a comprehensive characterization of blade resonances over a desired frequency range can be had by incrementally exciting the blades with various vibration frequencies F n and monitoring the blades for resonant responses.
A novel system and method have been presented for exciting the rotating blades of a turbomachine with selectable vibration frequencies. A method has also been illustrated for performing a comprehensive characterization of blade resonant frequencies in a machine under normal operating conditions. It is contemplated that changes in the components and arrangement of components in the novel system as well as changes in the precise steps of the inventive methods and the order of such steps may be made by those having ordinary skill in the art without departing from the spirit of the invention or the scope of the invention as set forth in the claims which follow. | System and method for characterizing the resonant responses of a plurality of rotating blades in a turbo machine. The system comprises a plurality of controllable fluid jets disposed about a blade row for exciting rotating blades with selectable frequencies of vibration. The sequential excitation of blades at a plurality of narrowly spaced frequencies and the simultaneous sensing of blade responses sufficiently resolves the resonant center frequencies and harmonics thereof in order to detect changes in characteristic blade resonances. | 6 |
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates generally to the field of storage and, more particularly, to an improved shelving system.
DESCRIPTION OF THE RELATED ART
[0002] Various types of shelving systems are known in the art. However, these shelves are typically difficult to assemble, and their assembly often requires various types of tools such as screwdrivers or wrenches. Furthermore, mechanisms, such as screws and nuts, used to attach the various components of these shelves often cause discontinuities on the outer surface of the shelves, which can be aesthetically displeasing and can have mechanical disadvantages.
[0003] Therefore, it would be advantageous to provide a shelving system that is simple to assemble without the use of tools and provides a fluent outer surface.
SUMMARY OF THE INVENTION
[0004] One aspect of the invention is to provide a shelving system that is capable of simple assembly that does not require the use of tools. Another aspect of the invention pertains to the use of a mechanism for attaching the various pieces of the system without causing interruptions in the aesthetic appearance of the outer surface of the shelves.
[0005] In one embodiment of the present invention, a shelving system is provided that includes first and second side frames, each of said side frames having at least one upwardly extending prong; a shelf frame having at least two connector sections, wherein each of said connector sections is in communication with one of said side frames; and wherein each connector section defines a vertical hole therein to receive one of said upwardly extending prongs.
[0006] These aspects are merely illustrative of the innumerable aspects associated with the present invention and should not be deemed as limiting in any manner. These and other aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the referenced drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Reference is now made more particularly to the drawings, which illustrate the depicted embodiments of the present invention and wherein similar reference characters indicate the same parts throughout the views.
[0008] FIG. 1 is a perspective view of a shelving system without any drawers attached according to an embodiment of the present invention.
[0009] FIG. 2 is a perspective view of a plastic connector piece.
[0010] FIG. 3 is a perspective view of a plastic connector piece in an attached state.
[0011] FIG. 4 is a perspective view of a plastic connector piece in an unattached state.
[0012] FIG. 5 is a perspective view of a top shelf in an unattached state.
[0013] FIG. 6 is a perspective view of an alternate embodiment of the connector portion.
[0014] FIG. 7 is a perspective view of an alternate embodiment of a tubular steel portion and a connector portion in an unattached state.
[0015] FIG. 8 is a perspective view of an alternate embodiment of a tubular steel portion and a connector portion in an attached state.
[0016] FIG. 9 is a perspective view of another alternate embodiment of the connector portion.
[0017] FIG. 10 is a perspective view of a shelving system with two drawers attached according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0018] In the following detailed description numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. For example, the invention is not limited in scope to the number of shelves or drawers depicted in the figures. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.
[0019] FIG. 1 illustrates an embodiment of a shelving system in the form of a cart 10 with three shelves according to the present invention. This embodiment comprises two side frames 12 , a top shelf 14 , a middle shelf 16 , and a bottom shelf 18 .
[0020] Each side frame 12 comprises an inverted u-shaped portion 20 , a plurality of prongs 22 , a horizontal stabilizing bar 24 , and two wheel portions 26 . The inverted u-shaped portion 20 may be tubular to reduce both the weight and cost of the cart 10 , while still maintaining sufficient strength for its intended uses. As described in more detail below, the prongs 22 extend upwardly and are used to attach the top shelf 14 , middle shelf 16 , and bottom shelf 18 to the side frames 12 . The horizontal stabilizing bar 24 provides rigidity to the side frame 12 and, thus, to the cart 10 as a whole. Both the horizontal stabilizing bar 24 and the prongs 22 may be welded or otherwise connected to the tubular, inverted u-shaped portion 20 . The wheel portions 26 provide mobility to the cart 10 , allowing an end user to move the cart 10 with minimal effort. The wheel portions 26 may have two sets of bearings, allowing rotation in both the horizontal and vertical planes, and may include a breaking mechanism.
[0021] The middle shelf 16 and the bottom shelf 18 comprise two outer members 30 and a plurality of support members 32 , wherein both the outer members 30 and the support members 32 are in the horizontal plane and the support members 32 are perpendicular to the outer members 30 . The support members 32 may be welded or otherwise attached to the outer members 30 . The support members 32 provide rigidity to the shelves, and thus to the cart 10 as a whole. The support members 32 also provide support for any drawers 50 that may be used, as discussed below.
[0022] In the depicted embodiment, the top shelf 14 comprises two outer members 30 , a plurality of support members 32 , and a plurality of intermediate members 34 . As in the case of the middle shelf 16 and bottom shelf 18 , the outer members 30 and support members 32 are in the horizontal plane and perpendicular to each other. The intermediate members 34 are parallel to and positioned between the outer members 30 . In the depicted embodiment, the intermediate members 34 are spaced at even intervals and are closer together than the support members 32 . In the depicted embodiment the intermediate members 34 add utility to the cart 10 by providing a useful top shelf 14 on which items may be placed. The intermediate members 34 may be welded or otherwise attached to the support members 32 .
[0023] In the depicted embodiment, each outer member 30 comprises a tubular steel portion 36 and two connector portions 38 . The tubular steel portion 36 may be attached to the connector portions 38 by glue, welding or other means, or held in place by friction or mechanical snaps incorporated onto the connector portions 38 and/or tubular steel portion 36 .
[0024] In the embodiments depicted in FIGS. 2-5 , each connector portion 38 contains a hole 42 passing, at least partially, vertically through the connector portion 38 . Each hole 42 is sized to receive a prong 22 , and each prong 22 is attached to the inverted u-shaped portion 20 in a position such that the top shelf 14 , middle shelf 16 and bottom shelf 18 will be desirably placed. In an alternative embodiment, multiple sets of prongs 22 may be attached to the inverted u-shaped portion 20 so as to provide an end user with multiple options for shelf configuration. The connector portion 38 is further comprised of a curved distal end 44 such that it fits flush with the u-shaped portion 20 . Thus, when all four connector portions 38 of a given shelf are in an attached position, i.e. when the prongs 22 are inserted in the holes 42 , the shelf is prevented from horizontal rotation or translation independent of the side frames 12 and is further prevented from vertical movement in the downward direction independent of the side frames 12 .
[0025] FIGS. 6-8 depict an alternative embodiment of the present invention in which the connector portion 38 is configured to be inserted into the tubular steel portion 36 of the outer member 30 . In this embodiment, the connector portion 38 is comprised of an insertion portion 46 and an external portion 48 and is configured such that the hole 42 passes through the insertion portion 46 . According to this embodiment, the hole 42 passes through the downwardly facing surface of both the connector portion 38 and the tubular steel portion 36 of the outer member 30 . The hole 42 does not pass through the upwardly facing surface of the tubular steel portion 36 , thereby preserving an uninterrupted aesthetic appearance on the upwardly facing surface of the tubular steel portion 36 . Thus, when a shelf is attached to a side frame 12 , the prong 22 passes through the downwardly facing surface of both the tubular steel portion 36 and the connector portion 38 .
[0026] Furthermore, according to this embodiment of the present invention, the connector portion 38 further comprises a protrusion 41 , and the tubular steel portion 36 further comprises a recess 43 for receiving the protrusion 41 . Thus, when the outer member 30 is assembled, the protrusion 41 is situated inside the recess 43 and prevents the connector portion 38 from rotating independently of the tubular steel portion 36 .
[0027] FIG. 9 depicts yet another alternative embodiment of the connector portion 38 in which the internal portion 46 of the connector portion 38 is cut off before the region of the tubular steel portion 36 that the hole 42 passes through. Thus, in this embodiment, when a shelf is attached to a side frame 12 , the prong 22 passes through the tubular steel portion 36 and does not pass through the connector portion 38 .
[0028] In the embodiment depicted in FIG. 10 drawers 50 are inserted to rest on the middle shelf 16 and the bottom shelf 18 . In the depicted embodiment, these drawers 50 comprise a five sided body 52 , having an open top, and a handle 54 . However, persons having skill in the art will recognize that numerous configurations are possible for the drawers 50 without departing from the scope of the invention. For example, the drawers 50 could include lids to cover the top, or the frontward facing surface of the drawers 50 could open to provide access to the contents of the drawer from the front by providing hinges on the bottom of the front surface.
[0029] In the depicted embodiments, the cart 10 , with the exception of the drawers 50 , the wheel portions 26 , and the connector portions 38 , is substantially made of steel. In the depicted embodiment, the drawers 50 could be made of a variety of materials such as plastic, fabric, cardboard, metal, wood or any other material known in the art for fabricating drawers. In the depicted embodiment the connector portions 38 are made of plastic, and the construction of the wheel portions 26 comprise a combination of plastics and metals as is well known in the art. However, persons skilled in the art will recognize that the various components of the present invention could be made of numerous and varied materials other than those disclosed in the embodiments depicted herein and that the use of such other materials for the construction of such various components are within the scope of the present invention.
[0030] Various embodiments of the invention have been described above to explain the principles of the invention and its practical application to thereby enable others skilled in the art to utilize the invention. However, as various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by the above-described embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents. | A shelving system includes first and second side frames, each of said side frames having at least one upwardly extending prong; a shelf frame having at least two connector sections, wherein each of said connector sections is in communication with one of said side frames; and wherein each connector section defines a vertical hole therein to receive one of said upwardly extending prongs. | 5 |
CROSS-REFERENCES TO RELATED APPLICATION
This application is a continuation-in-part of U.S. Ser. No. 12/136,934, filed on Jun. 11, 2008, now U.S. Pat. No. 7,465,700 which is a continuation-in-part of U.S. Ser. No. 11/765,516, filed on Jun. 20, 2007, now U.S. Pat. No. 7,396,808, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to cleaning compositions for use on hard surfaces. In one embodiment, the present invention relates to cleaning compositions for use on glass surfaces. The invention also relates to cleaning compositions for use with cleaning substrates, cleaning heads, cleaning pads, cleaning sponges and related systems for cleaning hard surfaces. The composition also relates to natural cleaning compositions having a limited number of ingredients and having good cleaning properties and low residue.
2. Description of the Related Art
Cleaning formulations have progressed and created a large chemical industry devoted to developing new synthetic surfactants and solvents to achieve ever improving cleaning compositions for the consumer. Because of a desire to use renewable resources, natural based cleaners are gaining increasing interest. Most of these cleaners contain only some natural ingredients. One difficulty in formulating natural based cleaners is achieving acceptable consumer performance with a limited number of natural components compared to highly developed formulations using synthetic surfactants and solvents.
Typical cleaning formulations require multiple surfactants, solvents, and builder combinations to achieve adequate consumer performance. For example, U.S. Pat. No. 5,025,069 to Deguchi et al. discloses alkyl glycoside detergent systems with anionic, amphoteric and nonionic surfactant ingredients. U.S. Pat. No. 7,182,950 to Garti et al. discloses nano-sized concentrates with examples using Tween® surfactants. U.S. Pat. No. 6,831,050 to Murch et al. discloses toxicologically acceptable cleaners containing oleic acid and citric acid. U.S. Pat. No. 6,302,969 to Moster et al. discloses natural cleaners containing anionic surfactants. U.S. Pat. No. 6,420,326 to Maile et al. discloses glass cleaners with ethanol, glycol ethers, and anionic surfactants.
Prior art compositions do not combine effective cleaning with a minimum number of ingredients, especially with natural ingredients. It is therefore an object of the present invention to provide a cleaning composition that overcomes the disadvantages and shortcomings associated with prior art cleaning compositions.
SUMMARY OF THE INVENTION
In accordance with the above objects and those that will be mentioned and will become apparent below, one aspect of the present invention comprises a hard surface cleaning composition consisting essentially of 0.1 to 5% alkyl polyglucoside; 0.5 to 5% of a solvent selected from the group consisting of sorbitol, glycerol, propylene glycol, 1,3-propanediol and mixtures thereof; 0.1 to 3% colloidal silica; water; and optionally dyes, builders, fragrances, fatty acids, colorants, and preservatives.
In accordance with the above objects and those that will be mentioned and will become apparent below, another aspect of the present invention comprises a hard surface cleaning composition consisting essentially of 0.1 to 5% alkyl polyglucoside; 0.5 to 5% of a solvent from the group consisting of sorbitol, propylene glycol, 1,3-propanediol and mixtures thereof; 0.05 to 5% glycerol; 0.1 to 3% colloidal silica; water; and optionally dyes, builders, fatty acids, fragrances, colorants and preservatives.
In accordance with the above objects and those that will be mentioned and will become apparent below, another aspect of the present invention comprises a hard surface cleaning composition consisting essentially of 0.1 to 5% alkyl polyglucoside; 0.5 to 5% of a solvent from the group consisting of sorbitol, propylene glycol, glycerol, 1,3-propanediol and mixtures thereof; 0.01 to 1% fragrance; 0.1 to 3% colloidal silica; water; and optionally dyes, builders, fatty acids, colorants and preservatives.
Further features and advantages of the present invention will become apparent to those of ordinary skill in the art in view of the detailed description of preferred embodiments below, when considered together with the attached claims.
DETAILED DESCRIPTION OF THE INVENTION
Before describing the present invention in detail, it is to be understood that this invention is not limited to particularly exemplified systems or process parameters that may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only, and is not intended to limit the scope of the invention in any manner.
All publications, patents and patent applications cited herein, whether supra or infra, are hereby incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference.
It must be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the content clearly dictates otherwise. Thus, for example, reference to a “surfactant” includes two or more such surfactants.
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 the invention pertains. Although a number of methods and materials similar or equivalent to those described herein can be used in the practice of the present invention, the preferred materials and methods are described herein.
In the application, effective amounts are generally those amounts listed as the ranges or levels of ingredients in the descriptions, which follow hereto. Unless otherwise stated, amounts listed in percentage (“%'s”) are in weight percent (based on 100% active) of the cleaning composition alone, not accounting for the substrate weight. Each of the noted cleaner composition components and substrates is discussed in detail below.
The term “cleaning composition”, as used herein, is meant to mean and include a cleaning formulation having at least one surfactant.
The term “surfactant”, as used herein, is meant to mean and include a substance or compound that reduces surface tension when dissolved in water or water solutions, or that reduces interfacial tension between two liquids, or between a liquid and a solid. The term “surfactant” thus includes, but is not limited to, anionic, cationic, nonionic, zwiterion and/or amphoteric agents.
The term “consisting essentially of” as used herein, limits the scope of a claim to the specified materials or steps “and those that do not materially affect the basic and novel characteristic(s)” of the claimed invention. In re Herz, 537 F.2d 549, 551-52, 190 USPQ 461, 463 (CCPA 1976) (emphasis in original). See MPEP 2111.03 For the purposes of searching for and applying prior art under 35 U.S.C. 102 and 103, absent a clear indication in the specification or claims of what the basic and novel characteristics actually are, “consisting essentially of” will be construed as equivalent to “comprising.” See, e.g., PPG, 156 F.3d at 1355, 48 USPQ2d at 1355. See MPEP 2111.03
The term “natural” as used herein is meant to mean at least 95% of the components of the product are derived from plant and mineral based materials. Also, the “natural” product is biodegradable. Additionally, the “natural” product is minimally toxic to humans and has a LD50>5000 mg/kg. The “natural” product does not contain of any of the following: non-plant based ethoxylated surfactants, linear alkylbenzene sulfonates (“LAS”), ether sulfates surfactants or nonylphenol ethoxylate (NPE).
The term “ecofriendly” as used herein is meant to mean at least 99% of the components of the product are derived from plant and mineral based materials. Also, the “ecofriendly” product is biodegradable. Additionally, the “ecofriendly” product is minimally toxic to humans and has a LD50>5000 mg/kg. The “natural” product does not contain of any of the following: non-plant based ethoxylated surfactants, linear alkylbenzene sulfonates (“LAS”), ether sulfates surfactants or nonylphenol ethoxylate (NPE).
The term “biodegradable” as used herein is meant to mean microbial degradation of carbon containing materials. The “biodegradable” material must be tested under a recognized protocol and with tested methods of established regulatory bodies such as: EPA, EPA- TSCA, OECD, MITI or other similar or equivalent organizations in the US or internationally. Suitable non-limiting examples of test methods for biodegradation include: OECD methods in the 301-305 series. Generally, all “biodegradable” material must meet the following limitations:
a) removal of dissolved organic carbon >70% b) biological oxygen demand (BOD) >60% c) % of BOD of theoretical oxygen demand >60% d) % CO2 evolution of theoretical >60%
Alkyl Polyglucoside
The cleaning compositions may contain alkyl polyglucoside (“APG”) surfactant. The cleaning compositions preferably have an absence of other nonionic surfactants, expecially synthetic nonionic surfactants, such as ethoxylates. The cleaning compositions preferably have an absence of other surfactants, such as anionic, cationic, and amphoteric surfactants. Suitable alkyl polyglucoside surfactants are the alkylpolysaccharides that are disclosed in U.S. Pat. No. 5,776,872 to Giret et al.; U.S. Pat. No. 5,883,059 to Furman et al.; U.S. Pat. No. 5,883,062 to Addison et al.; and U.S. Pat. No. 5,906,973 to Ouzounis et al., which are all incorporated by reference. Suitable alkyl polyglucosides for use herein are also disclosed in U.S. Pat. No. 4,565,647 to Llenado describing alkylpolyglucosides having a hydrophobic group containing from about 6 to about 30 carbon atoms, or from about 10 to about 16 carbon atoms and polysaccharide, e.g., a polyglycoside, hydrophilic group containing from about 1.3 to about 10, or from about 1.3 to about 3, or from about 1.3 to about 2.7 saccharide units. Optionally, there can be a polyalkyleneoxide chain joining the hydrophobic moiety and the polysaccharide moiety. A suitable alkyleneoxide is ethylene oxide. Typical hydrophobic groups include alkyl groups, either saturated or unsaturated, branched or unbranched containing from about 8 to about 18, or from about 10 to about 16, carbon atoms. Suitably, the alkyl group can contain up to about 3 hydroxy groups and/or the polyalkyleneoxide chain can contain up to about 10, or less than about 5, alkyleneoxide moieties. Suitable alkyl polysaccharides are octyl, nonyldecyl, undecyldodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl, di-, tri-, tetra-, penta-, and hexaglucosides, galactosides, lactosides, glucoses, fructosides, fructoses and/or galactoses. Suitable mixtures include coconut alkyl, di-, tri-, tetra-, and pentaglucosides and tallow alkyl tetra-, penta-, and hexaglucosides.
Suitable alkylpolyglycosides (or alkylpolyglucosides) have the formula: R 2 O(C n H 2n O) t (glucosyl) x wherein R 2 is selected from the group consisting of alkyl, alkylphenyl, hydroxyalkyl, hydroxyalkylphenyl, and mixtures thereof in which the alkyl groups contain from about 10 to about 18, preferably from about 12 to about 14, carbon atoms; n is about 2 or about 3, preferably about 2; t is from 0 to about 10, preferably 0; and x is from about 1.3 to about 10, preferably from about 1.3 to about 3, most preferably from about 1.3 to about 2.7. The glycosyl is preferably derived from glucose. To prepare these compounds, the alcohol or alkylpolyethoxy alcohol is formed first and then reacted with glucose, or a source of glucose, to form the glucoside (attachment at the 1-position). The additional glycosyl units can then be attached between their 1-position and the preceding glycosyl units 2-, 3-, 4-and/or 6-position, preferably predominantely the 2-position.
A group of alkyl glycoside surfactants suitable for use in the practice of this invention may be represented by formula I below:
RO—(R 2 O) y -(G) x Z b I
wherein R is a monovalent organic radical containing from about 6 to about 30 (preferably from about 8 to about 18) carbon atoms; R 2 is a divalent hydrocarbon radical containing from about 2 to about 4 carbon atoms; O is an oxygen atom; y is a number which has an average value from about 0 to about 1 and is preferably 0; G is a moiety derived from a reducing saccharide containing 5 or 6 carbon atoms; and x is a number having an average value from about 1 to 5 (preferably from 1.1 to 2); Z is O 2 M 1 , O 2 CR 3 , O(CH 2 ), CO 2 M 1 , OSO 3 M 1 , or O(CH 2 )SO 3 M 1 ; R 3 is (CH 2 )CO 2 M 1 or CH═CHCO 2 M 1 ; (with the proviso that Z can be O 2 M 1 only if Z is in place of a primary hydroxyl group in which the primary hydroxyl-bearing carbon atom, —CH 2 OH, is oxidized to form a —CO 2 M 1 group); b is a number from 0 to 3x+1 preferably an average of from 0.5 to 2 per glycosal group; p is 1 to 10, M 1 is H + or an organic or inorganic cation, such as, for example, an alkali metal, ammonium, monoethanolamine, or calcium. As defined in Formula I, R is generally the residue of a fatty alcohol having from about 8 to 30 or 8 to 18 carbon atoms. Suitable alkylglycosides include, for example, APG 325® (a C 9 -C 11 alkyl polyglycoside available from Cognis Corporation), APG 625® (a C 10 -C 16 alkyl polyglycoside available from Cognis Corporation), Dow Triton® CG110 (a C 8 -C 10 alkyl polyglycoside available from Dow Chemical Company), AG6202® (a C 8 alkyl polyglycoside available from Akzo Nobel) and Alkadet 15® (a C 8 -C 10 alkyl polyglycoside available from Huntsman Corporation). A C8 to C10 alkylpoly-glucoside includes alkylpolyglucosides wherein the alkyl group is substantially C8 alkyl, substantially C10 alkyl, or a mixture of substantially C8 and C10 alkyl. Additionally, short chain APGs such as C4 or C6 or mixtures thereof will be suitable with the present invention. Suitably, the alkyl polyglycoside is present in the cleaning composition in an amount ranging from about 0.01 to about 5 weight percent, or 0.1 to 5.0 weight percent, or 0.5 to 5 weight percent, or 0.5 to 4 weight percent, or 0.5 to 3 weight percent, or 0.5 to 2.0 weight percent, or 0.1 to 0.5 weight percent, or 0.1 to 1.0 weight percent, or 0.1 to 2.0 weight percent, or 0.1 to 3.0 weight percent, or 0.1 to 4.0 weight percent.
Solvent
The cleaning compositions can contain limited amounts of organic solvents, such as ethanol, sorbitol, glycerol, propylene glycol, and 1,3-propanediol, for example less than 10%, or less than 5%. Sugar alcohols can be suitable for the present invention. Sugar alcohols, include but are not limited to, sorbitol, propanol, glycerol, xilytol, lactitol, maltitol, mannitol, isomalt, erythritol, and mixtures thereof. Monohydric alcohols also can be suitable for the present invention. Monohydric alcohols include, but are not limited to, ethanol, methanol, isopropanol, n-propanol and butanol, t-butanol and mixtures thereof. Polyols are also suitable with the present invention. Polyols include but are not limited to, 1,3-propanediol, 1,3-propanetriol, ethylene glycol and propylene glycol and mixtures thereof. Fatty acid methyl ester can be suitable for the present invention. Fatty acid methyl ester, include but are not limited to, alkylated methyl esters (≦C 18), soy-derived fatty acid methyl ester, canola-derived fatty acid methyl ester. Short chain alcohols are also suitable with the present invention. Aloe leaf extract and d-limonine are also suitable solvents for the present invention. Additionally, natural derived triglycerides and lactate ester sorbitol are suitable solvents for the present invention. The compositions preferably contain solvents from natural sources rather than solvents from synthetic petrochemical sources, such as glycol ethers, hydrocarbons, and polyalkylene glycols. The compositions should be free of non-natural solvents such as C 1-6 alkanols, other C 1-6 diols, C 1-10 alkyl ethers of alkylene glycols, C 3-24 alkylene glycol ethers, polyalkylene glycols, short chain esters, isoparafinic hydrocarbons, mineral spirits, alkylaromatics, terpenes, terpene derivatives, terpenoids, terpenoid derivatives, formaldehyde, and pyrrolidones. Suitably, the solvent is present in the cleaning composition in an amount ranging from about 0.01 to about 10 weight percent, or 0.1 to 5.0 weight percent, or 0.1 to 4.0 weight percent, or 0.1 to 3.0 weight percent, or 0.1 to 2.0 weight percent, or 0.1 to 1.0 weight percent, or 0.5 to 5.0 weight percent, or 0.5 to 4.0 weight percent, or 0.5 to 3.0 weight percent, or 0.5 to 2.0 weight percent, or 0.5 to 1.0 weight percent.
The Nano-Particle Silica Dispersion
The cleaning compositions may contain nanoparticles of collidal silica. Nanoparticles, defined as particles with diameters of about 400 nm or less, are technologically significant, since they have novel and useful properties due to the very small dimensions of their particulate constituents. “Non-photoactive” nanoparticles do not use UV or visible light to produce the desired effects. Nanoparticles can have many different particle shapes. Shapes of nanoparticles can include, but are not limited to spherical, parallelepiped-shaped, tube shaped, and disc or plate shaped. Suitably, the colloidal silica is present in the cleaning composition in an amount ranging from about 0.1 to about 3 weight percent, or about 0.1 to about 2.5 weight percent, or about 0.1 to about 2.0 weight percent, or about 0.1 to about 1.5 weight percent, or about 0.1 to about 1.4 weight percent, or about 0.1 to about 1.3 weight percent, or about 0.1 to about 1.2 weight percent, or about 0.1 to about 1.1 weight percent, or about 0.1 to about 1.0 weight percent, or about 0.1 to about 0.8 weight percent, or about 0.1 to about 0.5 weight percent, or about 0.2 to about 1.0 weight percent, about 0.2 to about 0.8 weight percent.
Nanoparticles with particle sizes ranging from about 1 nm to about 400 nm can be economically produced. Particle size distributions of the nanoparticles may fall anywhere within the range from about 1 nm, or less, to less than about 400 nm, alternatively from about 2 nm to less than about 300 nm, alternatively from about 5 nm to less than about 150 nm, alternatively 1 nm to 100 nm, alternatively 5 nm and 50 nm, alternatively 1 nm and 25 nm, and alternatively 1 nm and 10 nm. Preferred ranges of the colloidal silica further include, but are not limited to, less than 400 nm, less than 350 nm, less than 300 nm, less than 250 nm, less than 200 nm, less than 175 nm, less than 150 nm, less than 125 nm, less than 100 nm, less than 90 nm, less than 80 nm, less than 75 nm, less than 70 nm, less than 60 nm, less than 50 nm, less than 40 nm, less than 30 nm, less than 25 nm, less than 20 nm, less than 10 nm, less than 9 nm, less than 8 nm, less than 7 nm, less than 6 nm, less than 5 nm, less than 4 nm, less than 3 nm, less than 2 nm and less than 1 nm. Commercial colloidal silica suspensions having a primary particle size between 5 to 150 nanometer (nm) and a surface area between 50-800 m.sup.2/g are suitable for use in the present invention. The surface area is generally measured by BET (see DIN 66131; originally described in JACS, Vol. 60, 1938, p. 309 by Brunauer, et al. Colloidal suspensions are generally preferred for ease of handling in preparing the inventive compositions, but these may also be prepared using any available source of colloidal silica according to methods known in the art.
The source of colloidal silica may be selected from silica dioxide, silicon dioxide, crystalline silica, quartz, amorphous fumed silica, food grade silica, flint, hydrophobic fumed silica, treated fumed silica, untreated fumed silica, amorphous fused silica, precipitated amorphous silica, microcrystalline silica, foundry sand, utility sand, fracturing sand, silica sand, silica, flint, glass sand, melting sand, engine sand, blasting sand, traction sand, hydraulic fracturing sands, filter sand, soft silica, condensed silica fume, cristobalite, tridymite, synthetic fused silica, hydrated precipitated silica, colloidal silica, silica dispersion, and silica aerogels. Further, silicas may be selected from the general categories of silicone dioxide (SiO 2 ) described as aerogel, amorphous, colloidal, crystalline, diatomaceous, food grade, fumed, fused, hydrophilic, hydrophobic, novaculite, precipitated, quartz and/or synthetic silica. Amorphous (CAS #7631-86-9), crystalline (CAS # 14808-60-7), and/or mixed type colloidal silica particles may be employed. Generally, amorphous silica forms are preferably employed for applications in which their improved safety characteristics are desirable. Also suitable is amorphous fumed silica, crystalline-free (CAS # 112945-52-5), amorphous hydrated silica and synthetic amorphous silica gel (SiO.sub.2xH2O, x=degree of hydration, CAS # 63231-67-4), precipitated silica gel, crystalline-free (CAS # 112926-00-8), amorphous, precipitated silica gel (CAS #7699-41-4), silica hydrate (CAS #10279-57-9), vitreous silica (CAS # 60676-86-0) and crystalline-free silicon dioxide (CAS #7631-86-9).
Suitable amorphous silicas commercially available in the preferred colloidal nanometer size domain include Ludox (available from Dupont), Klebosol (available from Clariant), Bindzil, Nyacol (both available from Akzo Nobel), Levasil (available from Bayer), Koestrosol (available from CWK), and Snowtex (available from Nissan Chemicals). For example, two varying sized colloidal silica products were evaluated, Bindzil 30/360FG (12 nm), 0.075 ppm and Klebosol 35 V 50 (70 nm), 0.10 ppm.
In one embodiment, the surface of the colloidal silica may be modified. Examples of colloidal silica (modified or unmodified) include, but are not limited to, Bindzil® 215 (anionic surface), Bindizil® 15/500 (anionic surface), Bindizil® 30/360 (anionic surface), Bindizil® 830 (anionic surface), Bindizil® 2034 DI (anionic, acid surface), Bindizil® 9950 (anionic surface), Bindizil® 50/80 (anionic surface), Bindizil® DP5110 (aluminum modified surface), Bindizil® 25AT/360 (aluminum modified surface), Bindizil® CAT80 (cationic surface) and Bindizil® CC30 (silane treated surface).
Fragrances
The cleaning compositions may contain natural essential oils or fragrances. The natural essential oils or fragrances may include lemon oil or d-limonine, a citrus-based fragrance or a vinegar-like (i.e. acetic acid) fragrance or mixtures thereof. Lemon oil or d-limonene helps the performance characteristics of the cleaning composition to allow suitable consumer performance with natural ingredients and a minimum of ingredients. Lemon oil and d-limonene compositions which are useful in the invention include mixtures of terpene hydrocarbons obtained from the essence of oranges, e.g., cold-pressed orange terpenes and orange terpene oil phase ex fruit juice, and the mixture of terpene hydrocarbons expressed from lemons and grapefruit. The essential oils may contain minor, non-essential amounts of hydrocarbon carriers. Suitably, fragrances are present in the cleaning composition in an amount ranging from about 0.01 to about 0.50 weight percent, or 0.01 to 0.40 weight percent, or 0.01 to 0.30 weight percent, or 0.01 to 0.25 weight percent, or 0.01 to 0.20 weight percent, or 0.01 to 0.10 weight percent, or 0.05 to 0.40 weight percent, or 0.05 to 0.30 weight percent, or 0.05 to 0.25 weight percent, or 0.05 to 0.20 weight percent, or 0.05 to 0.10 weight percent.
Essential oils include, but are not limited to, those obtained from thyme, lemongrass, citrus, lemons, oranges, anise, clove, aniseed, pine, cinnamon, geranium, roses, mint, lavender, citronella, eucalyptus, peppermint, camphor, sandalwood, rosmarin, vervain, fleagrass, lemongrass, ratanhiae, cedar and mixtures thereof. Preferred essential oils to be used herein are thyme oil, clove oil, cinnamon oil, geranium oil, eucalyptus oil, peppermint oil, mint oil or mixtures thereof.
Actives of essential oils to be used herein include, but are not limited to, thymol (present for example in thyme), eugenol (present for example in cinnamon and clove), menthol (present for example in mint), geraniol (present for example in geranium and rose), verbenone (present for example in vervain), eucalyptol and pinocarvone (present in eucalyptus), cedrol (present for example in cedar), anethol (present for example in anise), carvacrol, hinokitiol, berberine, ferulic acid, cinnamic acid, methyl salycilic acid, methyl salycilate, terpineol and mixtures thereof. Preferred actives of essential oils to be used herein are thymol, eugenol, verbenone, eucalyptol, terpineol, cinnamic acid, methyl salycilic acid, and/or geraniol.
Other essential oils include Anethole 20/21 natural, Aniseed oil china star, Aniseed oil globe brand, Balsam (Peru), Basil oil (India), Black pepper oil, Black pepper oleoresin 40/20, Bois de Rose (Brazil) FOB, Borneol Flakes (China), Camphor oil, Camphor powder synthetic technical, Canaga oil (Java), Cardamom oil, Cassia oil (China), Cedarwood oil (China) BP, Cinnamon bark oil, Cinnamon leaf oil, Citronella oil, Clove bud oil, Clove leaf, Coriander (Russia), Coumarin (China), Cyclamen Aldehyde, Diphenyl oxide, Ethyl vanilin, Eucalyptol, Eucalyptus oil, Eucalyptus citriodora, Fennel oil, Geranium oil, Ginger oil, Ginger oleoresin (India), White grapefruit oil, Guaiacwood oil, Gurjun balsam, Heliotropin, Isobomyl acetate, Isolongifolene, Juniper berry oil, L-methyl acetate, Lavender oil, Lemon oil, Lemongrass oil, Lime oil distilled, Litsea Cubeba oil, Longifolene, Menthol crystals, Methyl cedryl ketone, Methyl chavicol, Methyl salicylate, Musk ambrette, Musk ketone, Musk xylol, Nutmeg oil, Orange oil, Patchouli oil, Peppermint oil, Phenyl ethyl alcohol, Pimento berry oil, Pimento leaf oil, Rosalin, Sandalwood oil, Sandenol, Sage oil, Clary sage, Sassafras oil, Spearmint oil, Spike lavender, Tagetes, Tea tree oil, Vanilin, Vetyver oil (Java), and Wintergreen. Each of these botanical oils is commercially available.
Builders
The cleaning compositions may contain less than 0.2% builder, or no builder. Suitably, the builder is present in the cleaning composition in an amount ranging from about 0.01 to about 0.2 weight percent, or 0.01 to less than 0.2 weight percent, or 0.01 to 0.15 weight percent, or 0.01 to 0.10 weight percent, or 0.01 to 0.05 weight percent. The builder can be selected from inorganic builders, such as alkali metal carbonate, alkali metal bicarbonate, alkali metal hydroxide, alkali metal silicate and combinations thereof. These builders are often obtained from natural sources.
The cleaning composition can include a builder, which increases the effectiveness of the surfactant. The builder can also function as a softener, a sequestering agent, a buffering agent, or a pH adjusting agent in the cleaning composition. A variety of builders or buffers can be used and they include, but are not limited to, phosphate-silicate compounds, zeolites, alkali metal, ammonium and substituted ammonium polyacetates, trialkali salts of nitrilotriacetic acid, carboxylates, polycarboxylates, carbonates, bicarbonates, polyphosphates, aminopolycarboxylates, polyhydroxy-sulfonates, and starch derivatives. Builders, when used, include, but are not limited to, organic acids, mineral acids, alkali metal and alkaline earth salts of silicate, metasilicate, polysilicate, borate, hydroxide, carbonate, carbamate, phosphate, polyphosphate, pyrophosphates, triphosphates, tetraphosphates, ammonia, hydroxide, monoethanolamine, monopropanolamine, diethanolamine, dipropanolamine, triethanolamine, and 2-amino-2methylpropanol. Preferred buffering agents for compositions of this invention are nitrogen-containing materials. Some examples are amino acids such as lysine or lower alcohol amines like mono-, di-, and tri-ethanolamine. Other preferred nitrogen-containing buffering agents are tri(hydroxymethyl) amino methane (TRIS), 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl- propanol, 2- amino-2-methyl-1,3-propanol, disodium glutamate, N-methyl diethanolarnide, 2-dimethylamino-2-methylpropanol (DMAMP), 1,3-bis(methylamine)-cyclohexane, 1,3-diamino-propanol N,N′-tetra-methyl-1,3-diamino-2-propanol, N,N-bis(2-hydroxyethyl)glycine (bicine) and N-tris(hydroxymethyl)methyl glycine (tricine). Other suitable buffers include ammonium carbamate, citric acid, and acetic acid. Mixtures of any of the above are also acceptable. Useful inorganic buffers/alkalinity sources include ammonia, the alkali metal carbonates and alkali metal phosphates, e.g., sodium carbonate, sodium polyphosphate. For additional buffers see WO 95/07971, which is incorporated herein by reference. Other preferred pH adjusting agents include sodium or potassium hydroxide. The term silicate is meant to encompass silicate, metasilicate, polysilicate, aluminosilicate and similar compounds.
Fatty Acids
The cleaning composition can optionally contain fatty acids. A fatty acid is a carboxylic acid that is often with a long unbranched aliphatic tail (chain), which is saturated or unsaturated. Fatty acids are aliphatic monocarboxylic acids, derived from, or contained in esterified form in an animal or vegetable fat, oil or wax. Natural fatty acids commonly have a chain of 4 to 28 carbons (usually unbranched and even numbered), which may be saturated or unsaturated. Saturated fatty acids do not contain any double bonds or other functional groups along the chain. The term “saturated” refers to hydrogen, in that all carbons (apart from the carboxylic acid [-COOH] group) contain as many hydrogens as possible. In contrast to saturated fatty acids, unsaturated fatty acids contain double bonds. Examples of fatty acids that can be used in the present invention, include but are not limited to, butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachdic acid, behenic acid, lignoceric acid, myristoleic acid, palmitoleic acid, oleic acid, linoleic acid, alpha-linoleic acid, arachidonic acid, eicosapentaenoic acid, erucic acid, docosahexaenoic acid or mixtures thereof Suitably, fatty acids are present in the cleaning composition in an amount ranging from about 0.01 to about 1.0 weight percent, 0.01 to about 0.50 weight percent, or 0.01 to 0.40 weight percent, or 0.01 to 0.30 weight percent, or 0.01 to 0.25 weight percent, or 0.01 to 0.20 weight percent, or 0.01 to 0.10 weight percent, or 0.05 to 0.40 weight percent, or 0.05 to 0.30 weight percent, or 0.04 to 0.25 weight percent, or 0.04 to 0.20 weight percent, or 0.04 to 0.10 weight percent.
Dyes, Colorants and Preservatives
The cleaning compositions optionally contain dyes, colorants and preservatives, or contain one or more, or none of these components. These dyes, colorants and preservatives can be natural (occurring in nature or slightly processed from natural materials) or synthetic. Natural preservatives include benzyl alcohol, potassium sorbate and bisabalol; sodium benzoate and 2-phenoxyethanol. Preservatives, when used, include, but are not limited to, mildewstat or bacteriostat, methyl, ethyl and propyl parabens, short chain organic acids (e.g. acetic, lactic and/or glycolic acids), bisguanidine compounds (e.g. Dantagard and/or Glydant) and/or short chain alcohols (e.g. ethanol and/or IPA). The mildewstat or bacteriostat includes, but is not limited to, mildewstats (including non-isothiazolone compounds) including Kathon GC, a 5-chloro-2-methyl -4-isothiazolin-3-one, KATHON ICP, a 2-methyl-4-isothiazolin-3-one, and a blend thereof, and KATHON 886, a 5-chloro-2-methyl-4-isothiazolin-3-one, all available from Rohm and Haas Company; BRONOPOL, a 2-bromo-2-nitropropane 1, 3 diol, from Boots Company Ltd., PROXEL CRL, a propyl-p-hydroxybenzoate, from ICI PLC; NIPASOL M, an o-phenyl-phenol, Na + salt, from Nipa Laboratories Ltd., DOWICIDE A, a 1,2-Benzoisothiazolin-3-one, from Dow Chemical Co., and IRGASAN DP 200, a 2,4,4′-trichloro-2-hydroxydiphenylether, from Ciba-Geigy A.G. Dyes and colorants include synthetic dyes such as Liquitint® Yellow or Blue or natural plant dyes or pigments, such as a natural yellow, orange, red, and/or brown pigment, such as carotenoids, including, for example, beta-carotene and lycopene.
Water
When the composition is an aqueous composition, water can be, along with the solvent, a predominant ingredient. The water should be present at a level of less than 99.9%, more preferably less than about 99%, and most preferably, less than about 98%. Deionized water is preferred. Where the cleaning composition is concentrated, the water may be present in the composition at a concentration of less than about 85 wt. %.
pH
The pH of the cleaning composition is measured directly without dilution. The cleaning compositions using a standard anionic colloidal silica can have a pH of 7 or above, or 7.5 or above, or 8 or above, or 9 or above, or 10 or above, or from 7.5 to 11, or from 8 to 11, or from 9 to 11. The cleaning compositions using a standard anionic colloidal silica can also have a pH of 4 or below, 3 or below, 2 or below, 1 or below, or from 1 to 4, or from 2 to 4, or from 1 to 3 or from 0.5 to 3.5 or from 0.5 to 3.
The pH of the cleaning composition can be acidic or basic if the present invention uses surface modified anionic colloidal silica. If a modified anionic colloidal silica is used, the cleaning compositions can have a pH of 11 or below, 10 or below, 9 or below, 8 or below, 7 or below, 6 or below, or from 5 or below, or from 4 or below, or from 2 to 11, or from 3 to 10, or from 4 to 9, or from 5 to 8, or from 2 to 7.
If a cationic colloidal silica is used, the cleaning compositions can have a pH of 6 or below, or 5 or below, or 4 or below, or 3 or below, or 2 or below, or from 1 to 6, or from 2 to 5, or from 1 to 4, or from 2 to 4.
Substances Generally Recognized As Safe
Compositions according to the invention may comprise substances generally recognized as safe (GRAS), including essential oils, oleoresins (solvent-free) and natural extractives (including distillates), and synthetic flavoring materials and adjuvants. Compositions may also comprise GRAS materials commonly found in cotton, cotton textiles, paper and paperboard stock dry food packaging materials (referred herein as substrates) that have been found to migrate to dry food and, by inference may migrate into the inventive compositions when these packaging materials are used as substrates for the inventive compositions.
Suitable GRAS materials are listed in the Code of Federal Regulations (CFR) Title 21 of the United States Food and Drug Administration, Department of Health and Human Services, Parts 180.20, 180.40 and 180.50, which are hereby incorporated by reference. These suitable GRAS materials include essential oils, oleoresins (solvent-free), and natural extractives (including distillates). The GRAS materials may be present in the compositions in amounts of up to about 10% by weight, preferably in amounts of 0.01 and 5% by weight.
Prefered GRAS materials include oils and oleoresins (solvent-free) and natural extractives (including distillates) derived from alfalfa, allspice, almond bitter (free from prussic acid), ambergris, ambrette seed, angelica, angostura (cusparia bark), anise, apricot kernel (persic oil), asafetida, balm (lemon balm), balsam (of Peru), basil, bay leave, bay (myrcia oil), bergamot (bergamot orange), bois de rose (Aniba rosaeodora Ducke), cacao, camomile (chamomile) flowers, cananga, capsicum, caraway, cardamom seed (cardamon), carob bean, carrot, cascarilla bark, cassia bark, Castoreum, celery seed, cheery (wild bark), chervil, cinnamon bark, Civet (zibeth, zibet, zibetum), ceylon (Cinnamomum zeylanicum Nees), cinnamon (bark and leaf), citronella, citrus peels, clary (clary sage), clover, coca (decocainized), coffee, cognac oil (white and green), cola nut (kola nut), coriander, cumin (cummin), curacao orange peel, cusparia bark, dandelion, dog grass (quackgrass, triticum), elder flowers, estragole (esdragol, esdragon, estragon, tarragon), fennel (sweet), fenugreek, galanga (galangal), geranium, ginger, grapefruit, guava, hickory bark, horehound (hoarhound), hops, horsemint, hyssop, immortelle (Helichrysum augustifolium DC), jasmine, juniper (berries), laurel berry and leaf, lavender, lemon, lemon grass, lemon peel, lime, linden flowers, locust bean, lupulin, mace, mandarin (Citrus reticulata Blanco), marjoram, mate, menthol (including menthyl acetate), molasses (extract), musk (Tonquin musk), mustard, naringin, neroli (bigarade), nutmeg, onion, orange (bitter, flowers, leaf, flowers, peel), origanum, palmarosa, paprika, parsley, peach kernel (persic oil, pepper (black, white), peanut (stearine), peppermint, Peruvian balsam, petitgrain lemon, petitgrain mandarin (or tangerine), pimenta, pimenta leaf, pipsissewa leaves, pomegranate, prickly ash bark, quince seed, rose (absolute, attar, buds, flowers, fruit, hip, leaf), rose geranium, rosemary, safron, sage, St. John's bread, savory, schinus molle (Schinus molle L), sloe berriers, spearmint, spike lavender, tamarind, tangerine, tarragon, tea (Thea sinensis L.), thyme, tuberose, turmeric, vanilla, violet (flowers, leaves), wild cherry bark, ylang-ylang and zedoary bark.
Suitable synthetic flavoring substances and adjuvants are listed in the Code of Federal Regulations (CFR) Title 21 of the United States Food and Drug Administration, Department of Health and Human Services, Part 180.60, which is hereby incorporated by reference. These GRAS materials may be present in the compositions in amounts of up to about 1% by weight, preferably in amounts of 0.01 and 0.5% by weight.
Suitable synthetic flavoring substances and adjuvants that are generally recognized as safe for their intended use, include acetaldehyde (ethanal), acetoin (acetyl methylcarbinol), anethole (parapropenyl anisole), benzaldehyde (benzoic aldehyde), n-Butyric acid (butanoic acid), d- or l-carvone (carvol), cinnamaldehyde (cinnamic aldehyde), citral (2,6-dimethyloctadien-2,6-al-8, gera-nial, neral), decanal (N-decylaldehyde, capraldehyde, capric aldehyde, caprinaldehyde, aldehyde C-10), ethyl acetate, ethyl butyrate, 3-Methyl-3-phenyl glycidic acid ethyl ester (ethyl-methyl-phenyl-glycidate, so-called strawberry aldehyde, C-16 aldehyde), ethyl vanillin, geraniol (3,7-dimethyl-2,6 and 3,6-octadien-1-ol), geranyl acetate (geraniol acetate), limonene (d-, l-, and dl-), linalool (linalol, 3,7-dimethyl-1,6-octadien-3-ol), linalyl acetate (bergamol), methyl anthranilate (methyl-2-aminobenzoate), piperonal (3,4-methylenedioxy-benzaldehyde, heliotropin) and vanillin.
Suitable GRAS substances that may be present in the inventive compositions that have been identified as possibly migrating to food from cotton, cotton textiles, paper and paperboard materials used in dry food packaging materials are listed in the Code of Federal Regulations (CFR) Title 21 of the United States Food and Drug Administration, Department of Health and Human Services, Parts 180.70 and 180.90, which are hereby incorporated by reference. The GRAS materials may be present in the compositions either by addition or incidentally owing to migration from the substrates to the compositions employed in the invention, or present owing to both mechanisms. If present, the GRAS materials may be present in the compositions in amounts of up to about 1% by weight.
Suitable GRAS materials that are suitable for use in the invention, identified as originating from either cotton or cotton textile materials used as substrates in the invention, include beef tallow, carboxymethylcellulose, coconut oil (refined), cornstarch, gelatin, lard, lard oil, oleic acid, peanut oil, potato starch, sodium acetate, sodium chloride, sodium silicate, sodium tripolyphosphate, soybean oil (hydrogenated), talc, tallow (hydrogenated), tallow flakes, tapioca starch, tetrasodium pyrophosphate, wheat starch and zinc chloride.
Suitable GRAS materials that are suitable for use in the invention, identified as originating from either paper or paperboard stock materials used as substrates in the invention, include alum (double sulfate of aluminum and ammonium potassium, or sodium), aluminum hydroxide, aluminum oleate, aluminum palmitate, casein, cellulose acetate, cornstarch, diatomaceous earth filler, ethyl cellulose, ethyl vanillin, glycerin, oleic acid, potassium sorbate, silicon dioxides, sodium aluminate, sodium chloride, sodium hexametaphosphate, sodium hydrosulfite, sodium phospho-aluminate, sodium silicate, sodium sorbate, sodium tripolyphosphate, sorbitol, soy protein (isolated), starch (acid modified, pregelatinized and unmodified), talc, vanillin, zinc hydrosulfite and zinc sulfate.
Cleaning Substrate
The cleaning composition may be part of a cleaning substrate. A wide variety of materials can be used as the cleaning substrate. The substrate should have sufficient wet strength, abrasivity, loft and porosity. Examples of suitable substrates include, nonwoven substrates, wovens substrates, hydroentangled substrates, foams and sponges and similar materials which can be used alone or attached to a cleaning implement, such as a floor mop, handle, or a hand held cleaning tool, such as a toilet cleaning device. The terms “nonwoven” or “nonwoven web” means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted web. Nonwoven webs have been formed from many processes, such as, for example, meltblowing processes, spunbonding processes, and bonded carded web processes.
EXAMPLES
The compositions are simple, natural, high performance cleaning formulations with a minimum of essential natural ingredients. Competitive cleaners are either natural and inferior in performance or contain additional ingredients that make them non-natural, such as synthetic components. Because preservatives, dyes and colorants are used in such small amounts, these may be synthetic and the entire composition may still be characterized as natural. Preferably, the compositions contain only natural preservatives, dyes, and colorants, if any.
Table I illustrates all purpose cleaners of the invention. Table II illustrates glass cleaners of the invention. Table III illustrates additional cleaning compositions of the invention. Table IV shows that the compositions of the invention give equivalent performance to commercial non-natural, or synthetic cleaning compositions, and superior performance to commercial natural cleaning compositions. Table V illustrates additional cleaning compositions of the invention. Table VI illustrates cleaning compositions in the form of a lotion pre-loaded onto a wipe substrate made of natural biodegradable fibers (cotton, lyocell, etc.).
TABLE I
All Purpose
Cleaner
A
B
C
D
E
F
Glucopon ®
2.24
3.00
1.00
5.00
1.50
3.00
425N 1
Ethanol
1.16
3.00
0.50
5.00
1.50
1.50
Glycerol
0.22
0.30
0.10
1.00
0.50
0.30
Lemon oil
0.22
0.30
0.10
0.40
0.20
Essential oil w
0.25
D-Limonene
Preservative
0.005
None
0.002
0.001
0.01
0.005
and Dye
Sodium
0.15
0.10
Carbonate
Water
balance
balance
balance
balance
Balance
balance
1 Coco glucoside from Cognis.
TABLE II
Glass Cleaner
G
H
I
J
K
L
Glucopon ®
0.60
1.50
0.30
0.50
0.50
1.00
425N
Ethanol
2.00
3.00
1.50
0.50
1.00
2.00
Glycerol
0.11
0.20
0.05
0.05
0.10
0.20
Lemon oil
0.20
0.05
0.05
Essential oil w
0.05
0.10
0.15
D-Limonene
Preservative
0.005
0.005
0.005
0.005
0.005
0.005
and Dye
Sodium
0.07
0.20
0.05
0.15
0.15
Carbonate
Water
balance
balance
balance
balance
Balance
balance
TABLE III
All Purpose
Cleaner
M
N
O
P
Glucopon ® 215 1
2.00
2.00
Glucopon ® 225 2
1.50
Glucopon ® 325 3
0.50
Glucopon ® 600 4
Ethanol
1.00
1.00
1.00
2.00
Glycerol
0.20
0.20
0.10
0.15
Lemon oil
0.10
0.20
D-Limonene
0.15
Essential oil with
0.20
d-limonene
Preservative and
0.005
0.005
0.005
0.005
Dye/Colorant
Sodium
0.50
Bicarbonate
Sodium
0.05
0.05
Hydroxide
Sodium Silicate
0.05
0.05
Water
balance
balance
balance
Balance
1 Capryl glucoside from Cognis.
2 Decyl glucoside from Cognis.
3 C9-C11 glucoside from Cognis.
4 Lauryl glucoside from Cognis.
TABLE IV
ASTM
Filming
Streaking
Cleaner
Bathroom
Mirrors
Mirrors
Formula A
Basis
Lysol ® Antibacterial Spray
equal
Seventh Generation ® Natural
less
Citrus Cleaner and Degreaser
Method ® All Purpose Surface
less
Cleaner
Formula G
Basis
Basis
Windex Vinegar Multisurface
Equal
Equal
Seventh Generation ® Free and
less
Equal
Clear Glass and Surface Cleaner
Method ® Window Wash Glass
equal
Less
and Surface Cleaner
TABLE V
Glass Cleaner
Components
Q
R
S
T
Ethanol
2.0
2.5
2.5
2.5
Glucopon ® 425
0.60
0.30
0.10
0.20
Glycerine
0.11
0.11
0.00
0.11
Sodium Carbonate
0.07
0.00
0.00
0.00
Colloidal Silica
0.00
0.80
0.80
0.80
(i.e. Bindzil
30/360)
Fragrance
0.05
0.05
0.05
0.00
Deionized Water
97.2
96.2
96.6
96.4
TABLE VI
Cleaner
Components
U
V
W
Ethanol
3.947
3.947
3.947
Glucopon ® 225
0.857
0.000
0.000
DK (APG)
Alkadet 35 (APG)
0.000
0.160
0.080
SL 10 (APG)
0.000
0.317
0.000
Glucopon ® 425N
0.000
0.000
0.220
(APG)
Glycerine
0.111
0.111
0.111
Sodium Carbonate
0.110
0.110
0.110
Colloidal Silica
1.000
1.000
1.000
Oleic Acid
0.050
0.050
0.050
Fragrance
0.150
0.150
0.150
Deionized Water
93.775
94.155
94.332
pH of Lotion
10.0
10.0
10.0
pH of lotion wipe
7.0-8.0
7.0-8.0
7.0-8.0
Colloidal Silica
8 nm
8 nm
8 nm
Particle Size
TABLE VII
Glass Cleaner
Components
X
Y
Z
AA
Sorbitol
2.5
0.00
0.00
0.00
1,3-Propanediol
0.00
2.5
0.00
0.00
Glycerol
0.00
0.00
2.5
0.00
Propylene Glycol
0.00
0.00
0.00
2.5
Glucopon ® 425
0.60
0.30
0.10
0.20
Sodium Carbonate
0.07
0.00
0.00
0.00
Colloidal Silica
0.80
0.80
0.80
0.80
(i.e. Bindzil
30/360)
Fragrance
0.05
0.05
0.05
0.00
Deionized Water
96.0
96.4
96.6
96.5
TABLE VIII
Glass Cleaner
Components
BB
CC
DD
EE
Sorbitol
2.5
0.00
0.00
0.00
1,3-Propanediol
0.00
2.5
0.00
0.00
Glycerol
0.5
0.5
2.5
0.5
Propylene Glycol
0.00
0.00
0.00
2.5
Glucopon ® 425
0.60
0.30
0.10
0.20
Sodium Carbonate
0.00
0.07
0.00
0.00
Colloidal Silica
0.80
0.80
0.80
0.80
(i.e. Bindzil
30/360)
Fragrance
0.05
0.05
0.05
0.00
Deionized Water
95.6
95.8
96.6
96.0
Without departing from the spirit and scope of this invention, one of ordinary skill can make various changes and modifications to the invention to adapt it to various usages and conditions. As such, these changes and modifications are properly, equitably, and intended to be, within the full range of equivalence of the following claims. | A cleaning composition with a limited number of natural ingredients contains alkyl polyglucoside, solvent and colloidal silica. The cleaning composition optionally has an additional amount of glycerol. The cleaning composition optionally has a small amount of fragrance. The cleaning composition can be used to clean hard surfaces and cleans as well or better than commercial compositions containing synthetically derived cleaning agents. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a disposable surgical safety scalpel. More particularly, the present invention relates to a disposable surgical safety scalpel with a retractable blade inside a hollow handle with a novel locking and unlocking arrangement that enables easy use and ensures safety in pre-use, use, and post-use conditions.
BACKGROUND OF THE INVENTION
[0002] Scalpels are widely used in surgery the world over. Surgical scalpels have sharp cutting edges on the blades, which makes them dangerous to use for the surgical team. The potential for accidents when for example the scalpel is being passed back and forth during an operation, is very high. Similarly during post-use, the disposal of the scalpel also poses a problem, in that the slightest negligence during handling in the postoperative time frame can also result in accidents unless extreme care is exercised.
[0003] In recent years, the spread of communicable diseases such as Hepatitis, AIDS and such other diseases makes it important to ensure that safety features are built into the surgical scalpel such that the potential for accidental harm be falling the handler or any person in the vicinity, inadvertently is minimized. A study by Dr. Jannie Jagger in April 1995 on the “Advances in exposure prevention” published by International Health Care Workers and Safety, Research and Resource Center, shows that 34% of scalpel wounds occur during the use of the scalpel in an operative procedure, while 39% occurs when the scalpel is passed from hand to hand during an operation, and the balance 27% when disposal of the scalpel is being effected.
[0004] Hepatitis—B, AIDS and other blood carried diseases all can be communicated during the operative stage. Since detection and treatment of the above diseases is not possible at the time that a scalpel used accidentally cuts or nicks a person, the normal presumption is that all the persons who are involved in an operative procedure are exposed to risk of infection. Additionally, to ensure that injury is not caused during the disposal stage of the scalpel, it must be ensured that the blade is suitably inaccessible and protected such that the disposal of the scalpel is made free of the potential for injury.
[0005] Several methods are provided in the art to ensure that the scalpel during all of pre-use, use and post-use conditions is safe and does not cause accidental harm to the handler.
[0006] In the art, surgical scalpels have been provided with a blade shield or guard in order to ensure that the safe packaging of the product and thus its sterility is maintained. But the solution does not take care of the problem in the use and post operative stage.
[0007] U.S. Pat. No. 2,735,176 discloses a surgical knife that is provided with a hollow handle which functions as a sheath for the blade that is extendable slidingly and retractable between a first cutting position and a second shielded position. Movement of the blade requires the surgeon to positively act to at least rearrange the handle in his/her hand. In some embodiments, it requires a two-handed actuation of the shield to ensure that the blade is properly sheathed before transfer to another person. Another disadvantage of the sheath system for surgical knives is that they require complex locking and retraction mechanisms. Such mechanisms often prove to be extremely fragile and expensive to incorporate resulting in an increase in cost of manufacture. The increased cost of manufacture of such scalpels renders the disposal factor not very attractive for the user. Similar to the scalpel disclosed in the above patent, U.S. Pat. Nos. 3,905,101 and 3,906,626 disclose sheaths wherein the handle carrying the blade is slideble from a first protective position to a second cutting position and vice versa. However, to initiate the sliding action, two-handed actuation is required rendering the instrument user unfriendly.
OBJECTS OF THE INVENTION
[0008] The main object of the present invention is to provide a disposable safety scalpel wherein the blade is protected from exposure during pre- and post-use conditions.
[0009] It is another object of the present invention to provide a disposable safety scalpel where bringing the cutting edge of the blade into the operational mode requires a specific actuation by the user.
[0010] It is another object of the present invention to provide a disposable safety scalpel with a retractable blade that is user friendly and with a firm locking arrangement to ensure safety in handling during operative stage.
[0011] It is another object of the present invention to provide a disposable safety scalpel where the potential for pre- and post-operative accidental injury to the user or to other persons in the vicinity are completely eliminated or substantially minimized.
[0012] It is a further object of the invention to provide a disposable safety scalpel with a permanent locking mechanism in the post use stage to ensure total or at least substantial safety in disposal of the scalpel post—use.
SUMMARY OF THE INVENTION
[0013] Accordingly, the present invention provides a disposable safety scalpel comprising a housing with a proximal open end to enable sliding in and out of the blade carrier to expose the cutting edge of the scalpel blade and a distal closed end, a blade carrier slideably provided in such housing, said blade carrier being provided with a scalpel blade fixedly located on one end thereof, the other end of the blade carrier being provided with a plurality of locking means to enable locking of the blade in three positions of pre-use, actual use and post use disposal stage, said blade carrier also being provided with a sliding means to enable movement of the blade carrier within the housing, the housing being provided with lock cooperating mechanisms at three positions thereon corresponding to pre-use, use and post-use disposal stages, said lock cooperating mechanisms cooperating with the respective locking means provided on said blade carrier during use.
[0014] In one embodiment of the invention, the blade carrier is provided with actuating means to enable positive movement of the blade carrier from a first pre-use stage to an actual use stage and finally to a post-use disposal stage.
[0015] In another embodiment of the invention, the first locking mechanism for the pre-use stage comprises of at least one lug provided on the blade carrier and cooperating with a depression provided on said housing to ensure pass locking.
[0016] In another embodiment of the invention, the second in-use locking mechanism comprises of at least a pair of matched arms extending in the longitudinal direction from the end of the blade carrier opposite the blade end and provided with lugs cooperating with a corresponding second pair of slots provided in the flange on said housing, said pair of slots being adapted to receive the lugs on said arms and retain them therein permanently till actual release by the user.
[0017] In a further embodiment of the invention, the second in-use locking mechanism is provided with an actuating means to enable release of the blade carrier from the use position to the pass position by natural action of retraction.
[0018] In a further embodiment of the invention, the third arm provided on the said blade carrier to ensure permanent locking of the blade by wedge locking it to the end piece in the post use disposal stage.
[0019] In another embodiment of the invention, the housing is provided with a groove running on one side thereon to enable sliding movement of the blade carrier thereon from a pass position to a in use position as required during operation, and to a third permanent locking position for the post-use disposal stage.
[0020] In another embodiment of the invention, the blade carrier is provided with a actuating means to enable movement of the blade carrier from the pass to in use stage and finally to a post-use disposal stage.
[0021] In a further embodiment of the invention, the actuating means provided on said blade carrier comprises a knob.
[0022] In another embodiment of the invention, the slots on the housing are adapted to receive the said second locking mechanism and the third locking mechanism are provided respectively on opposite sides of the housing.
[0023] In another embodiment of the invention, the notches on the housing are adapted to receive the said first locking mechanism and the second locking mechanism are provided respectively on the same side of the housing.
[0024] In a further embodiment of the invention, the knob and the mechanisms are integral enabling movement of the blade carrier and locking simultaneously.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0025] [0025]FIG. 1 is an isometric view of the disposable safety scalpel of the invention with the blade shown in a cutting position.
[0026] [0026]FIG. 2 is a schematic representation of the housing with the groove shown to enable the carrier to slide. The housing has a bottom, two side walls and two flanges at the top showing the in use locking position and a groove between the flanges for actuating the knob for the lateral movement of the carrier.
[0027] [0027]FIG. 3 is a schematic representation of the blade carrier without the blade showing the different locking means provided thereon.
[0028] [0028]FIG. 4 is a schematic representation of the knob provided on the blade carrier with the respective locking means for pass and in use stages shown thereon.
[0029] [0029]FIG. 5 is a schematic representation of the rear end stopper provided on the housing showing tapper wedge for disposable locking.
[0030] [0030]FIG. 6 is a schematic representation of the blade carrier with the knob and the locking means being integral inter se.
DETAILED DESCRIPTION OF THE INVENTION
[0031] In the operating room, surgical scalpels are often transferred back and forth between the operating surgeon and the other personnel assisting in the operation. The transfer of instruments during surgery is often dictated by considerations of speed. As such, the use of scalpels during surgery often result in cuts and nicks due to the rapid transfer from one person to another. The spread of communicable diseases such as Hepatitis and AIDS and other blood carried diseases has rendered the operation theater fraught with risk for the operating personnel. It is therefore important to devise instruments, which avoid or at least minimize substantially the risk of operating room personnel being infected with communicable diseases due to accidental injuries suffered during the course of operation.
[0032] Simlarly, after the completion of the surgical procedures, it has now become mandatory whether by way of statutory regulations or in house policies of most hospitals to dispose of instruments such as scalpels which are invasive and have come into direct contact with the patient. Disposal of such instruments such as scalpels poses a problem due to the sharp cutting edge of the blade. Disposal therefore inevitably requires tremendous safety precautions and it is not unknown for accidental cuts and nicks to occur during disposal of such instruments to the persons handling such equipment.
[0033] The present invention is a disposable safety scalpel with a retractable blade and a novel locking mechanism. The invention will be described in detail below with reference to the accompanying drawings.
[0034] Referring now to FIG. 1, an isometric view of the disposable safety scalpel according to the invention is shown with the blade being displayed in a cutting or operating position.
[0035] The housing ( 1 ) is provided with a groove ( 3 ) which holds the blade carrier ( 2 ). The blade carrier ( 2 ) is provided with a knob ( 4 ) which is slideable in the groove ( 3 ) from a first in use position ( 5 ) to a second pass position ( 6 ) and after use to a final disposal position ( 7 ) where the blade is permanently locked. The blade carrier ( 2 ) is also provided with a first locking means ( 8 ) to ensure locking of the blade carrier in the housing in the in use position ( 5 ), a second locking means ( 9 ) to ensure locking in the pass position ( 6 ). A third locking means ( 10 ) is provided on said blade carrier ( 2 ) to ensure permanent locking of the blade carrier( 2 ) with the blade( 11 ) in a retracted position (not shown) when the scalpel is ready for disposal. As a result of the permanent disposal locking position, the safety of handlers during disposal is ensured. Similarly, the easy locking transfer between the pass position and the in use position ensures that transfer of the scalpel during operation does not result in any accidental nick or cut to the user or handler.
[0036] [0036]FIG. 2 is a schematic representation of the housing with the different locking positions indicated thereon. The housing ( 21 ) is provided with a first pair of slots( 22 ) to enable locking of the blade carrier (not shown) in a first in use position. Since the slots ( 22 ) are engaged in a relatively rigid manner by the corresponding lugs provided on the blade carrier, the actual positive force required to be applied by the user will not cause unlocking of the blade carrier from the first in use position to the second pass position. This ensures that the blade carrier remains in a rigid position in actual use and the potential of the accidental retraction during surgery is avoided. The release of the in use locks by the natural forces of retraction necessary to bring the carrier to the past position. At each stage of the surgical procedure requiring the use of the scalpel, the blade carrier can be retracted to a pass position ( 23 ) where a releasable locking means is provided. This ensures the safety of those assisting personnel who handle the scalpel after the completion of the specific surgical maneuver. After the completion of the entire surgical procedure, the blade carrier can be retracted to a third and final locking position comprising a slot ( 24 ) provided in the end stopper( 21 ). This permanent locking ensures that the potential for accidental nicks and cuts during post operative disposal of used surgical instruments is avoided
[0037] [0037]FIG. 3 is a schematic representation of the blade carrier without the blade showing the different locking means provided thereon. The first locking means ( 32 ) cooperates with a corresponding pair of slots provided on the housing (see FIG. 2) to ensure a rigid locking during in use position for the blade carrier. This ensures that accidental retraction of the blade during actual surgical maneuver does not occur. However, the blade can be retracted from the first in use position by direct application of force on an actuator comprising a knob ( 34 ) to release the first locking means from the corresponding slots provided on the housing. The blade then retracts into the pass position and stay locked therein due to the second locking means( 33 ) provided on the blade carrier. Since the second locking means is releasable, the scalpel can be reused during the same surgical procedure by simply pushing the knob to move in the groove provided on the housing (not shown) to push the blade into a first in use position. After final completion of the surgical procedure, the blade carrier is pushed back to a final permanent locking position where a third locking means ( 35 ) provided on the blade carrier engage a notch on the housing to ensure permanent locking. In this final stop position, the blade carrier cannot be released accidentally, thereby ensuring complete safety of the operator.
[0038] [0038]FIG. 4 is a schematic representation of the knob provided on the blade carrier with the respective locking means for safe, in use and post use stages shown thereon. The knob is used for exposing and retracting the blade as required. The in use lock are pressed into the slots provided in the two flanges of the housing. During in use position, the lock components engage two slots provided on the housing and the elasticity of the plastic carrier spring ensures firm locking during this position. The firm locking and the closed tolerance between the hollow handle and the slideable carrier provide stability to the blade during the surgical procedure. After use, the blade can be retracted. The movement of the knob in the groove provided on the housing first releases the in use lock by downward pressure. The knob is provided with two pads for the specific application of pressure in a downward direction on the first locking means to ensure their release. Further retraction of the blade after release from the in use position brings the blade carrier to a second pass position where the locking means is a releasable locking means. If the scalpel is required again during the surgical procedure, the blade carrier can simply be extended to the in use position where the first locking means operates as described above. If the scalpel is not required any longer, the blade carrier can simply be retracted by actuation using the knob to a final stop position where the third locking means acts to ensure permanent locking of the blade carrier. At this stage, the scalpel is ready for disposal with no risk of any accidental injury. In one embodiment the knob and the locking means are integral inter se (see FIG. 6).
[0039] [0039]FIG. 5 is a schematic representation of the rear end stopper provided on the housing to ensure disposable locking. The operation of the rear end stopper is to ensure a permanent locking of the blade carrier after completion of the surgical procedure where the blade is ready for disposal.
[0040] [0040]FIG. 6 is a schematic representation of the blade carrier with the knob and the locking means being integral inter se. The blade carrier ( 61 ) is provided with the knob ( 62 ) located centrally on the flat portion thereon. The knob functions to push the blade carrier between the various operative and non-operative (pass and dispose-off positions) on the application of an actuating force by the user. The locking at the various positions (operative, pass, and dispose-off) is provided with respective locking means ( 63 , 64 and 65 respectively).
[0041] The embodiments described above are illustrative and various modifications are possible within the scope and spirit of the invention. The figures describe specific preferred embodiments and should not be construed as limiting the scope of the invention in any manner. | The present invention relates to a disposable surgical safety scalpel with a retractable blade inside a hollow handle with a novel locking and unlocking arrangement that enables easy use and ensures safety in pre-use, use, and post-use conditions. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates generally to a tool storage system for use in golf courses, and more specifically, to rake storage systems for use in close proximity to a golf course sand trap.
To the chagrin of golfers everywhere, many an errant golf shot has ended with the golf ball rolling into a sand trap. The player having hit the ball then follows into the sand trap to strike at the ball with his next swing. Typically the action of the player walking on the sand in addition to the divot he takes when he swings at the ball leaves the sand within the sand trap disturbed, and if left unattended, affecting the roll of the next ball hit into the sand trap. Out of courtesy to other players, after a player has cleared his ball from the sand trap, he is expected to leave the sand trap in the same undisturbed condition as when he found it. To help him smooth over the sand trap, many golf courses leave rakes either in the sand trap or along side it. The disadvantage of leaving the rake in the sand trap or along side it is the potential that a golf ball will strike the rake, thereby affecting the trajectory of the ball and distorting the shot.
Various devices have been conceived in order to provide the player with ready access to the rake while still locating the rake beyond a golf ball's path. One device conceals the rake in a container in the golf course thereby preventing the ball from striking the rake while the rake is not in use. This device by Edward C. Erichson, U.S. Pat. No. 3,584,739, utilizes a container buried in the ground adjacent to a sand trap for storage of the sand trap rake. The container has a hinged cover having an artificial turf surface mounted flush with the ground. When the rake is not in use, the container is covered, and the rake is entirely hidden from sight. The cover itself forms a playing surface across which the ball can roll.
Another device by Cash, U.S. Pat. No. 4,934,550 discloses a rake storage system somewhat similar to Erichson in that the rake is concealed in a container buried in a golf course, the difference being that Erichson covers the the rake and the container, while Cash does not.
Other inventions have been devised which make the rake a collapsible rake and therefore easily carried by the golfer as he walks the golf course. Examples of this type of sand trap rake include W. J. Walsh, U.S. Pat. No. 2,110,538 and E. F. Walker, U.S. Pat. No. 2,821,834. Still another collapsible rake is by D. L. Burrows, U.S. Pat. No. 3,390,516 and a detachable rake head which attaches to a golf club head by W. N. Fallon, U.S. Pat. No. 3,210,111.
By using a collapsible rake, the rake is carried with the player, thereby leaving no rake near the sand trap. The disadvantage of this is that when a player comes by without a rake he has no means by which to smooth over the sand trap. A rake inserted within a container and covered by an artificial turf lid near a sand trap distorts the feature of the golf course by having an artificial turf section. In addition the rake cannot be seen thereby potentially requiring some sort of sign or other marking.
The present invention disposes only the rake handle into the ground and allows only the rake head to be visible and on display. The golfer can readily spot the location of the rake, retrieve it to smooth over the sand trap after his shot, and when finished slide the rake handle into a storage tube buried in the ground leaving the rake head fully exposed. Furthermore, the location of the storage tube beneath a sand trap fringe also minimizes the chance of a ball hitting the rake head itself.
A rake laying around the sand trap not only provides an obstacle for the ball itself, but may be dangerous to the inattentive player stepping on it. The present invention eliminates this problem while still keeping the rake on display and accessible to all golfers on the golf course. The rake storage system design is also not prone to breakage or malfunction, and does not present an added cost of an extra tool that each individual golfer must bear.
Finally, the rake storage system is adaptable to any type of golf course tool around any hazard. For example, if a player encounters a water hazard, he either has to retrieve his ball by himself with his hands, or carry with him a long handled ball scoop in his golf bag. With the present storage system, the tube can be inserted in the ground near the water hazard, with the golf ball scoop insertable into the tube. The scoop is displayed so that the player can look to it, retrieve his ball, and then reinsert the tool within the storage tube. With such tools, the advantage of the present tool storage system is that only the head of the tool is displayed to attract a player's attention, and by careful location of the storage tube, the tool presents a minimal obstruction to golf ball trajectories.
SUMMARY OF THE INVENTION
According to one embodiment the present invention provides a rake having an elongated handle with a bottom end and a top end, a rake head with rake tines at the top end of the handle, an elongated storage tube disposable into an earthen wall forming a perimeter of a sand trap, the tube being disposed at an angle ranging from approximately 0 to 30 degrees relative to the earthen wall, the tube having a bottom end and a top end, the top end of the tube having an opening which is substantially flush with the earthen wall, the top end of the tube having an insertable lid, the bottom end of the tube being tapered toward the center of the tube, the bottom end of the tube having a drainage opening, a sleeve insertable in the tube, the sleeve being removable and having an upper end with an opening for receiving the bottom end of the rake handle, the sleeve being sufficiently small to prevent passage of the rake head therethrough, the sleeve having indexing means comprising a longitudinal indexing slot and an angled receiving end, the rake handle having indexing means comprising a tab protruding from the rake handle, wherein the tab engages the angled end of the sleeve in a cam action to rotate the rake handle until the tab engages the slot, thereby orienting the rake head with its rake tines pointed downward when the rake is inserted in the tube.
According to another embodiment the indexing means comprises a tube disposable into the earthen wall at a non-vertical angle, a handle defining a handle axis, a rake head which is weighted so that the rake head has a center of mass that is at a distance from the handle axis, thereby orienting the rake head with its rake tines pointed downward when the rake is stored in the tube.
According to another embodiment, the indexing means comprises the tube upper opening having a noncircular shape and the rake having a noncircular shape incorporated into the top end of the rake handle, so that the noncircular shape of the handle nests into the noncircular shape of the upper opening to orient the rake head with its rake tines pointed downward when the rake is stored in the tube.
A general object of the present invention is to provide a rake storage system for use near a golf course sand trap which displays the rake to a golfer and is convenient for the golfer to use, while at the same time minimizing the rake as an obstacle to a golf ball's path.
Another related object of the present invention is to provide a rake storage system which displays a rake while at the same time minimizing the rake as an obstacle to a golf ball's path, and which can be easily incorporated by a golf course thereby relieving the golfer of the burden of carrying a rake and providing a rake to any and all golfers playing through a particular sand trap.
Another related object of the present invention is to provide a rake storage system which does not alter any of the usable golf course playing surface while at the same time minimizing the rake as an obstacle to a golf ball's path, thereby maintaining a pristine playing surface while still conveniently presenting the rake to any and all golfers.
Another related object of the present invention is to provide an indexing feature which orients the rake head for the golfer as he inserts the rake into the tube so that the chance for erroneous insertion are reduced thereby further minimizing the chance for a golf ball to hit the rake once the rake is installed.
Other related objects and advantages of the present invention are disclosed in the following description of the preferred embodiments.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation partial cross-sectional view of a first embodiment of the present invention depicting the rake partially installed.
FIG. 2 is a side elevation partial cross-sectional view of the device of FIG. 1 depicting the rake fully installed.
FIG. 3 is a fragmented side cross-sectional view of the first embodiment showing the storage tube, sleeve, and indexing slot of the present invention.
FIG. 4 is a side elevation view showing the rake of the first embodiment of the present invention.
FIG. 5 is a cross-sectional view taken along line 5--5 in FIG. 3 showing the indexing feature of the rake handle inside the sleeve of the present invention.
FIG. 6 is a side cross-sectional view showing the storage tube, sleeve, and indexing feature for a second embodiment of the present invention.
FIG. 7 is a cross-sectional view taken along line 7--7 of FIG. 6 showing an alternate indexing feature on the second embodiment of the present invention.
FIG. 8 is a partial perspective view showing the indexing feature on the rake of the second embodiment of the present invention.
FIG. 9 is a side elevation view showing the rake of the second embodiment of the present invention.
FIG. 10 is a side elevation partial cross-sectional view of a third embodiment of the present invention.
FIG. 11 is a side elevation partial cross-sectional view showing an optional lid and its placement into the tube of the present invention.
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 embodiments 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 method, 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 now to FIG. 1, a typical installation is shown of a rake storage system 20 located within a sand trap 21. Rake storage system 20 is comprised of a storage tube 23 and a rake 41. In this illustration, rake 41 is shown partially inserted within storage tube 23. Rake 41 is comprised of a handle 25 and a rake head 37 which also incorporates a raking feature. Although many raking features will perform the desired raking function, rake head 37 incorporates tines (or teeth) 39 as its raking feature. Although rake storage system 20 can be used anywhere within close proximity to sand trap 21, the best location is where storage tube 23 is located underneath a sand trap lip 27 and above the sand 31 within sand trap 21. A hole 35 is first drilled or otherwise dug into the earthen wall 29 surrounding the sand trap 21, and storage tube 23 is then inserted into drilled hole 35. Drilled hole 35 should be of sufficient diameter to provide a close fit with tube 23, thereby locking tube 23 in place once it is inserted into the ground. Tube 23 can be inserted into earthen wall 29 at any angle between horizontal and vertical; however, in the illustrated embodiment, an angle 33 of 0 to 30 degrees relative to vertical provides the best performance.
Referring now to FIG. 2 rake 41 is shown fully inserted into tube 23. The exposed end 43 of tube 23 is shown flush with the earthen wall 29. Although exposed end 43 can be upstanding from the earthen wall 29, the preferred flush installation allows rake head 37 to be nearer to the earthen wall 29 and therefore less exposed. As illustrated in FIG. 2, a golf ball's momentum will result in a trajectory 45 over rake head 37 before embedding in the sand 31. For this reason rake storage system 20 should be located in wall 29 of sand trap 21 so that the majority of golf ball trajectories will pass over rake head 37 similar to trajectory 45. Ideally, this location should be in wall 29 toward the tee and away from the green so that the rake is not in the way of the golf ball approaching the green. FIG. 2 also shows rake head 37 in its preferred orientation; that is, with tines 39 of rake 41 pointed downward toward the bottom of sand trap 21, thereby also minimizing rake head 37 exposure to golf ball trajectory 45.
Because it is preferable to have tines 39 pointing downward, a mechanism for indexing rake 41 with respect to tube 23 is provided. A positive indexing mechanism automatically orients rake head tines 39 downward as rake 41 is inserted into tube 23, regardless of the initial orientation of rake 41 at the beginning of its insertion.
FIG. 3 and FIG. 4 depict the individual tube and rake assemblies and also depict the preferred indexing mechanism. In FIG. 3 a sleeve 49 is insertable within tube 23. Sleeve 49 is removable thus allowing for cleaning of leaves, dirt and other debris, and for repair. Sleeve 49 incorporates a ramped camming surface 53 (FIG. 3) and a vertical slot 51 for indexing of rake 41 with respect to the tube and sleeve and about the rake handle's longitudinal axis. Sleeve 49 also has encircling a portion of its outer diameter a collar 57. This collar is located at the bottom of indexing slot 51 and provides support for sleeve 49 when inserted within tube 23. Sleeve 49 and tube 23 have correlating holes through which a fastener 55 is inserted which attaches sleeve 49 to tube 23, thereby orienting the indexing slot 51 to the earthen wall 29 via tube 23. A fastener 61 is bolted through tube 23 to provide a stop for sleeve 49, so that the weight of the sleeve and rake when installed is supported between fastener 55 and fastener 61. Sleeve 49 also incorporates at its bottom end a cap 59 which is permanently attached. Tube 23 also employs a permanently attached cap 63 at its bottom. Cap 63 is tapered to assist in the insertion of tube 23 into hole 35 in earthen wall 29. Cap 63 further provides for drainage by having an opening 64 therein.
Referring now to FIG. 3, FIG. 4 and FIG. 5, rake 41 has a typical cylindrical rake handle 25, although other shapes such as an oval or a triangular shape are envisioned as well. To provide for indexing, a tab 65 is incorporated and protrudes outward, preferably near the top end of the rake handle 25. Tab 65 is oriented on rake handle 25 relative to rake bead 37 so that tab 65 engages within indexing tube slot 51 to position rake head 37 with tines 39 pointing downward. The automatic indexing mechanism is provided by the cam action of tab 65 as it contacts the angled surface 53 of sleeve 49. Upon contact with angled surface 53, tab 65 will rotate while sliding down surface 53, engaging slot 51 at the end of rake 41 rotation as shown in FIG. 5.
Tube 23 and sleeve 49 can be of many different configurations and materials while still performing in the manner described above. The optimum configuration is a balance of function, cost, and complexity. In the preferred embodiment among other considerations the material chosen is a balance of cost versus the ability to resist weathering and corrosive effects. Because tube 23 and sleeve 49 will encounter the most moisture due to their location in the ground, a plastic material is utilized for the illustrated embodiment, and to reduce cost standard PVC tubing is utilized. The rake handle 25 can be any typical rake handle material such as wood or plastic. If plastic is used, the tab 65 and rake head 37 can be molded directly into the handle itself. Keeping in mind initial cost as well as repair and replacement cost however, the preferred embodiment employs a standard wooden rake handle with tab 65 and rake head 37 fastened to wooden handle 25. Tab 65 is made from nylon, although any low friction durable material may be used, and tab 65 is screwed into handle 25. As an alternative approach, tab 65 can be a sleeve of a durable material which is trapped by a headed fastener to the handle, so that the sleeve is able to rotate about the fastener resulting in a rolling rather than a sliding motion. Although not the preferred embodiment, a hollow handle can be chosen as well, and in that case a wooden dowel could be inserted into handle 29 to provide a threadable base for tab 65 to be attached.
Although rake 41 and tube 23 can be of many sizes, in the preferred embodiment, rake handle 25 has a 1 inch diameter, and tube 23 is made from 2 inch diameter PVC plastic tubing (keeping in mind that PVC tubing is sold by inner diameter size, thus a 2 inch diameter PVC tube has an inner diameter of 2 inches and an outer diameter of approximately 23/8 inches). Sleeve 49 is made from 1 inch diameter PVC plastic tubing.
Referring now to FIG. 3, in the preferred embodiment the tube 23 inserted in the ground is approximately 6 feet long. The sleeve 49, which is removable for cleaning, is a lessor length than the tube length itself and is approximately 5 feet, leaving 1 foot of clearance between the bottoms of sleeve 49 and tube 23. Angled surface 53 is cut at a 30 degree angle relative to vertical and slot 51 is approximately 3/8 inch wide so that a 3/8 inch tab can slide into it. The length of angled surface 53 and slot 51 combine so that the bottom of the slot is 1 foot from the uppermost portion of sleeve 49. Fastener 61 bolts through tube 23 approximately 11 5/16 inches from the bottom of tube 23 and can be any standard bolt and nut combination. In the preferred illustration, however, a 10-24×21/2 long bolt and nut combination is used. Fastener 55 is similar to fastener 61, however it is only 1 inch long giving a 10-24×1 flat head machine screw and nut combination.
Referring now to FIG. 4, rake 41 has handle 25 with a length of 41/2 feet. Tab 65 is fastened to handle 25 approximately 10 inches from rake head 37. The location of tab 65 on handle 25 is somewhat critical in that if tab 65 is located too near rake head 37, the automatic indexing mechanism of tab 65 into angled surface 53 will attempt to rotate rake 41 when rake 41 is almost fully inserted into tube 23. Because rake head 37 has a width associated with it, the rake head 37 will not be able to rotate due to interference with either the sodded fringe 27 or the sand 31. The location of tab 65 is therefore chosen to prevent this potential interference while still maintaining the desirous feature of having rotation occurring when rake 41 is mostly installed into tube 23, thereby providing a more stable system. The rake head 37 can be of a common design; however, in this embodiment, the rake head 37 is 2 inches wide with the tines 39 being 1 inch long. The rake head length itself is determined by the size of the sand trap. If it is a large sand trap, the rake head length would be sufficient so as to require relatively few raking actions to smooth over the sand trap. If the sand trap is small, however, the rake head would also have to be sufficiently short so as not to protrude from the earthen wall into a golf ball trajectory.
Other mechanisms are provided by this invention. Referring now to FIG. 6 and FIG. 7, an alternate embodiment is depicted having a sleeve 70 which is installed and supported at the exposed edge 74 of tube 73 and which has a uniquely oriented non-circular shape 71 to the upper portion 72 of its length. Referring now to FIGS. 8 and 9, the rake handle 75 incorporates in a portion of its length a corresponding non-circular shape 79. The remaining portion 77 of handle 75 is circular, although other shapes would be equally functional. The noncircular shape 79 is incorporated along the top 1 foot portion of rake handle 75. Where the rake handle 75 transfers from a circular rake handle 77 to the noncircular shape 79 will be the point 78 at which the engagement begins as rake handle 75 is installed into sleeve 72.
The non-circular shape 79 can be most any shape; however, it is preferred that the shape is chosen so that the rake can only be installed in a downward position. Another shape for instance may be that of non-equilateral triangle.
Still another alternate embodiment is shown in FIG. 10 having indexing means which consist of a specially weighted sand trap rake 85 in combination with a tube 87 inserted at a non-vertical angle 89. Rake handle 91 defines a central axis 93, and rake head 95 has a center of mass 97 which is at an eccentric distance 99 from central axis 93. The gravity effect on rake 85 results in rake head 95 being at rest only with tines 92 pointed downward, thereby automatically orienting rake head 95 downward as rake 85 is inserted into tube 87.
Another feature which can be included in any of the above embodiments and is included in the preferred embodiment is a lid 101 shown in FIG. 11 which covers the tube when the rake is not installed, such as during the off-season. The lid may be fastened via a chain, hinged to exposed end 43, or threaded into exposed end 43. In the preferred embodiment, lid 101 is a molded plastic piece which inserts into exposed end 43 when rake 41 is not installed. Lid 101 has a handle 103 which provides a grasping surface so that lid 101 can be easily removed. Although it is envisioned that the hinged means of attachment, for example, would provide a lid that is always present whether the rake is installed or not, the preferred embodiment employs lid 101 when rake 41 is not installed for longer periods of time than just when in use by a golfer. Lid 101 provides protection of tube 23 and sleeve 49 from any moisture, dirt or anything else which could fall into tube 23 when rake 41 is not installed.
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 rake storage system is disclosed for use in close proximity to golf course sand traps. This system includes a storage tube which is insertable in the ground and a golf course rake whose handle slides into the tube so that only the rake head is exposed. Also included in this system is a sleeve which slides into the tube to provide an indexing mechanism which automatically rotates the rake to a desired orientation as the rake is inserted in the tube. Indexing is accomplished by a tab incorporated onto the rake handle engaging a slot incorporated within the sleeve. In another embodiment, the rake handle has a uniquely shaped upper portion which engages in a sleeve with a like shaped upper portion so that the rake is at the desired orientation when the rake is installed in the tube. In yet another embodiment, the rake head is of a specific shape and weight so that the rake head center of mass is at a distance from an axis defined by the rake handle, thereby creating a gravity effect on the rake which rotates the rake downward as the rake is inserted in the tube. | 0 |
BACKGROUND OF THE INVENTION
It is known in the art to attach a platform to a vehicle for increasing the carrying capacity of the vehicle. The platform generally consists of a rectangular surface that attaches to a trailer or receiver hitch on the vehicle. In this manner, the platform undesirably extends the length of the vehicle. However, the benefit of carrying additional cargo external to the vehicle generally outweighs the detriment of lengthening the vehicle.
When additional carrying capacity is not needed, it is desirable to store the platform in a convenient, readily accessible location. One solution, as shown in U.S. Pat. Nos. 4,744,590; 6,382,486; and 6,513,690, is to fold the platform toward the vehicle and leave the platform attached to the vehicle in this folded position. Although this solution ensures that the platform is readily accessible, the platform still adds some length to the vehicle. In addition, the folded platform may be aesthetically undesirable or it may interfere with the vehicle's trunk or tailgate operation.
Another solution is to remove the platform from the vehicle and store the platform until needed. Although this solution restores the vehicle to its original length, the platform is generally too bulky to store inside the vehicle, and storing the platform separate from the vehicle limits the accessibility of the platform.
Therefore, the need exists for a cargo carrier that can increase the carrying capacity for a vehicle and that can also be conveniently stored with the vehicle when not in use.
SUMMARY OF THE INVENTION
Objects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In one embodiment of the invention, an apparatus for attaching to a vehicle for carrying cargo includes a base, a mounting sleeve for attaching the apparatus to the vehicle, and a wing moveably connected to the base. The wing has extended and retracted positions so that the wing is substantially coplanar with the base in the extended position and transverse to the base in the retracted position. Furthermore, the apparatus occupies a smaller volume when the wing is in the retracted position than when the wing is in the extended position.
In other embodiments of the invention, the apparatus may include more than one wing moveably connected to the base. One or more of the wings may include an inner section moveably attached to an outer section so that the inner section resides within the outer section in the retracted position. Alternately, the outer section may reside in the inner section in the retracted position. The apparatus may further include a locking mechanism for locking one of the wings in the retracted position.
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which: . . .
FIG. 1 is a perspective view of an embodiment of the present invention;
FIG. 2 is a close-up perspective view of the embodiment depicted in FIG. 1 ;
FIG. 3 is a perspective view of the embodiment depicted in FIG. 1 as partially folded;
FIG. 4 is a perspective view of the embodiment depicted in FIG. 1 as fully folded; and
FIG. 5 is a perspective view of an alternate embodiment of the present invention as partially folded.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
The present invention relates to a collapsible cargo carrier that attaches to a vehicle to increase the carrying capacity of the vehicle. When not in use, the carrier folds up for convenient detachment and storage within the vehicle.
As shown in FIG. 1 , the carrier 10 generally includes a base 20 , a mounting sleeve 30 , and one or more wing assemblies 40 . The base 20 provides a sturdy foundation to which the other components may attach. The base 20 is typically a flat, solid structure, as shown in FIG. 1 , or it may include perforations to reduce its weight. The base 20 may be made of metal, plastic, fiberglass, or a combination thereof, depending on the particular uses and needs. The base may include one or more raised sides 22 to further define the carrier 10 and provide additional attachment points.
The mounting sleeve 30 fixedly attaches to the base 20 and provides a means for attaching the carrier 10 to a vehicle. As shown in FIG. 1 , the mounting sleeve 30 may be a square collar 32 with an aperture 34 suited to mate with a drawbar 36 from a conventional receiver hitch. The mounting sleeve 30 receives the drawbar 36 , and a clevis pin, cotter pin, bolt, or other suitable structure (not shown) fits through a hole 38 in the mounting sleeve 30 and drawbar 36 to secure the mounting sleeve 30 to the drawbar 36 . In other embodiments, the mounting sleeve 30 may be a clamp, vice grip, or other structure more suitable for securely engaging the carrier 10 to a ball-type trailer hitch.
The wing assemblies 40 moveably connect to the base 20 and provide the remainder of the surface area for carrying cargo. FIG. 1 illustrates one embodiment of a carrier 10 with symmetric, multi-sectional wing assemblies 40 on opposing sides of the carrier's longitudinal axis, although other orientations are within the scope of the present invention. Moreover, although FIG. 1 depicts an embodiment with each wing assembly 40 having an inner section 41 and an outer section 42 , it should be understood by one of ordinary skill in the art that wing assemblies 40 having fewer or more sections are within the scope of the present invention.
Each wing assembly 40 includes an expanded metal surface 44 , vertical siding 46 , and horizontal support bars 48 . The expanded metal surface 44 extends between the vertical siding 46 and provides the horizontal surface area for carrying cargo. The use of expanded metal reduces the weight of the wing assembly 40 ; however, it should be understood by one of ordinary skill in the art that a solid sheet of material is an equivalent substitute within the scope of the present invention.
The vertical siding 46 defines the perimeter and provides additional structural support for the wing assemblies 40 . The vertical siding 46 may include a slideable attachment 50 and/or a locking mechanism, as shown in more detail in FIG. 2 . The slideable attachment 50 allows relative movement between two parts, such as between the wing assembly 40 and the base 20 or between inner 41 and outer 42 sections of the wing assembly 40 . The slideable attachment 50 may use rivets, bolts, hinges, slides, or other suitable substitutes. In alternate embodiments, the slideable attachment 50 may be located on other parts of the wing assembly 40 , such as the underside of the expanded metal surface 44 and/or horizontal support bars 48 .
The locking mechanism secures the wing assembly 40 in a desired position. Although various suitable mechanisms are known to one of ordinary skill in the art and within the scope of the present invention, one such mechanism is a spring button 60 depicted in FIGS. 1 , 2 , and 3 . As shown, the spring button 60 attaches to the vertical siding 46 at one end 62 and has a button (not shown) at the other end 64 . The button fits into a detent 66 in the vertical siding 46 to lock the wing assembly 40 into retracted or extended positions.
The horizontal support bars 48 extend between the vertical siding 46 and provide structural support for the expanded metal surface 44 . In one embodiment, the horizontal support bars 48 attach to the vertical siding 46 using rivets, bolts, tack welds, or similar suitable methods. The expanded metal surface 44 then attaches to the horizontal support bars 48 in similar fashion. In another embodiment, the vertical siding 46 includes a support flange 49 , and the horizontal support bars 48 attach to the support flange 49 . The expanded metal surface 44 in turn attaches to the horizontal support bars 48 and/or the vertical siding 46 . It should be understood by one of ordinary skill in the art that alternate embodiments within the scope of the present invention may employ other methods for securing the expanded metal surface 44 , vertical siding 46 , and horizontal support bars 48 .
FIGS. 1 , 3 , and 4 illustrate one embodiment of the present invention in various positions. In FIG. 1 , the carrier 10 is fully extended, as it would be when installed on a vehicle. To fully retract one wing assembly 40 , as depicted in FIG. 3 , the outer section 42 of the wing assembly 40 folds into the inner section 41 . The spring button 60 is then depressed to unlock the wing assembly 40 , and the entire wing assembly 40 rotates roughly perpendicular to the base 20 until the spring button 60 locks the wing assembly 40 in a fully retracted position. FIG. 4 depicts the carrier 10 in a fully retracted position, as it would be when installing or removing the carrier 10 on a vehicle or when the carrier 10 is in storage.
FIG. 4 depicts an additional feature present in some embodiments of the present invention. As shown, the wing assemblies 40 may further include a U-shaped structure 70 attached to the horizontal support bars 48 , or other suitable structure on the wing assembly 40 . When the wing assembly 40 is in the folded position, the U-shaped structure 70 serves as a convenient handle for moving the carrier 10 . In the extended position, the U-shaped structure 70 is beneath the expanded metal surface 42 and provides additional support for the wing assembly 40 .
FIG. 5 depicts an alternate embodiment of the present invention with a modified wing assembly 80 . The modified wing assembly 80 includes an extension slide 82 mounted on the vertical siding 46 for slideably connecting the inner 41 and outer 42 sections. The extension slide 82 includes a ball bearing or nylon roller 84 that rides in a track 86 between the inner 41 and outer 42 sections, although other types of extension slides are known to one of ordinary skill in the art and within the scope of the present invention. In the modified wing assembly 80 , the outer section 42 slides on the extension slide 80 toward or away from the base 20 to reach a retracted or extended position, respectively. In this manner, the carrier has retracted and extended positions, as before. In addition, the carrier also has intermediate positions in which the modified wing assemblies 80 are rotated to be coplanar with the base 20 while one or both of the outer sections 42 remains retracted within its associated inner section 41 .
It should be appreciated by those skilled in the art that modifications and variations can be made to the embodiments of the invention set forth herein without departing from the scope and spirit of the invention as set forth in the appended claims and their equivalents. | The present invention discloses and claims an apparatus for attaching to a vehicle for carrying cargo. The apparatus includes a base and at least one wing having retracted and extended positions. The apparatus occupies a smaller volume when the wing is retracted than when the wing is extended. | 1 |
BACKGROUND OF THE INVENTION
A variety of electroplating baths have been disclosed for the electrodeposition of bright tin upon metallic substrates. These baths have been substantially acidic and have been utilized in many industrial applications. Typical of such disclosed baths include those described in U.S. Pat. Nos. 3,361,652; 3,471,379 and 3,875,029.
Many of these aforementioned baths contain surface active agents and the baths aforementioned typically contain a brightener. While these baths have proven generally satisfactory and have been widely utilized in a commercial setting, they are usually deficient in one or more desirable operating characteristics, and the deposits produced thereby frequently fail to provide a balance of characteristics such as smoothness, brightness, adherence, solderability and stability to resist aging, particularly in the presence of copper ions present as contaminants in the acid plating baths.
Therefore, while various of the baths described in the literature are operable with varying degrees of effectiveness, there has remained a need to provide a means for treating a copper-contaminated bath to produce a bath which is again capable of producing smooth adherent deposits exhibiting spectral brightness over a wide current density range.
It has now been determined that by utilizing sodium formaldehyde sulfoxylate as an additive, a copper-contaminated acid tin or tin-metal alloy electroplating bath can be treated to regenerate a bath which is substantially stable and is capable of producing bright, smooth, fine-grained deposits over a wide cathode current density range upon continued electrolysis.
SUMMARY OF THE INVENTION
In accordance with the invention, there is provided a means for treating an aqueous acidic bath for the electrodeposition of tin or tin/metal which has become contaminated by copper comprising adding from about 0.01 to about 10.0 grams per liter of sodium formaldehyde sulfoxylate.
The addition of sodium formaldehyde sulfoxylate to the contaminated acid plating baths according to the present invention eliminates the undesirable overall plating haze and low current density dullness caused by the presence of copper contamination in the acid plating bath. Bright tin or tin-metal deposits can be obtained over a wide current density range upon continued operation of the bath.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The compositions treated in accordance with the present invention exhibit the desired bright plating activity, particularly on copper and copper alloy substrate and are further characterized in that an extended bath life is realized.
The treating method of the present invention is based upon the discovery that the addition of sodium formaldehyde sulfoxylate to an acid electroplating bath will minimize or eliminate the adverse effects of copper contamination on the acid bath.
In a preferred embodiment of the present invention the acid bath which is treated will comprise an aqueous solution of a free acid, stannous or a mixture of stannous and metal ions and sodium formaldehyde sulfoxylate. It is advantageous to include normal brightening agents, and surface active agents can also be included in the bath compositions. These components can be present in an amount of from about 5% to about 40% of free acid; from about 0.1% to about 10% of tin; from about 0.1% of other metal ion; and from about 0.01% to about 10% of sodium formaldehyde sulfoxylate. When present in the composition the brightening agent comprises from about 0.001% to about 10% of the composition and the surface active agent will constitute from about 0.1% to about 8.0%.
The free acid can be sulfuric acid, fluoboric acid or mixtures thereof. Most commonly sulfuric acid will be employed.
Other metals which can be combined with the tin are lead and nickel.
Representative examples of brightening agents which can be employed in the compositions of the present invention are benzaldehyde, cinnamaldehyde and anisaldehyde.
Any of the surface active agents known to the art for use in electroplating baths can be employed. Representative examples are the alkoxylated fatty acid alkylolamides and the alkyl phenoxypolyethoxyethanols.
Other conventional components of tin plating baths can be present in the compositions of the present invention. Thus, there can be included antioxidants and foam suppressors.
The following examples illustrate the invention.
EXAMPLE 1
A bath was prepared by adding 2 ounces per gallon of tin metal to 10 percent by volume of 66° Baume sulfuric acid in 1 gallon of water, 4 percent by volume of ELECTRO-BRITE, a commercial surfactant-brightener mixture, and 150 parts per million of copper in the form of copper sulfate. The Hull cell panel plated at 1 ampere for 5 minutes indicated a hazy and dull plate over the entire range.
ELECTRO-BRITE is a trademark of Dart Industries, Inc.
EXAMPLE 2
Plating tests were carried out in a Hull cell under the same conditions and employing an identical bath to that used in Example 1 except that an additional 4 percent by volume of the surfactant-brightener mixture of Example 1 was employed. The Hull test panel again indicated a hazy and dull plating.
EXAMPLES 3 AND 4
The identical procedure of Example 1 was carried out employing baths to which there had been added, respectively, sodium formaldehyde bisulfite and formaldehyde solution. Again, the test results were unsatisfactory.
EXAMPLE 5
One percent by volume of a 100 grams/liter solution of sodium formaldehyde sulfoxylate was added to the copper-contaminated tin bath of Example 1 with thorough mixing and allowed to stand overnight. The resulting brick red solution was filtered.
The Hull cell panels plated from the thus-treated bath indicated full bright strong platings.
Copper impurity levels were checked by atomic absorption spectroscopy with the following results:
______________________________________Additive Copper Content______________________________________None 141 ppm copper1% sodium formaldehyde 33.7 ppm coppersulfoxylate2% sodium formaldehyde 3.4 ppm coppersulfoxylate______________________________________
The results reported above demonstrate that the presence of sodium formaldehyde sulfoxylate significantly reduces the copper contamination in acid tin baths and enables the realization of bright clear panels.
It will be obvious to those skilled in the art that various modifications can be made to the specific embodiments discussed above. All such departures from the foregoing specification are considered to be within the scope of this invention as disclosed in this specification and defined by the appended claims. | A method for removing copper contaminants from acid electroplating baths comprising adding to the bath sodium formaldehyde sulfoxylate. The presence of the sodium formaldehyde sulfoxylate overcomes overall plating haze and low current density dullness due to copper contamination in the acid tin bath. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system for directing an apparatus, such as a crane bridge, which moves on wheels along rails.
2. Description of the Related Art
In a situation where apparatuses, such as crane bridges which are elongated in the transverse direction with respect to rails, are driven along the rails at a distance from one another, the wheels of the apparatus to be driven are maintained in the middle of the rails by means of mechanical guide rollers. The guide rollers provide some freedom of action so that the mechanical elasticity and deflections of the apparatus to be driven will be managed. However, for cranes, in particular, where the span length of the bridge is long and the driving speed is high, the wear of mechanical guide rollers or other such structural parts is a significant problem.
When bridge driving is accomplished with two or more motor drives with a precise speed control, it is often necessary to compensate the speeds specifically for each motor drive because there are generally many differences in the speed directions and the actual speed of the drives such that the crane bridge tends to be driven aslant. The speed differences between the ends of the bridge are due to both mechanical factors (e.g. differences in wheel dimensions because of wear, for example) and electrical factors (small differences in speed directions because of component tolerances and signal routes, for example).
These problems are attempted to be solved by the control systems for even driving a crane bridge disclosed in references GB-A-2 112 548, DE-A-25 28 293 and DE-A-28 35 688, for example, where the distance of the end of the bridge from the rail is measured with two separate detectors. The controller directs the difference of the distance measurement of the detectors to a desired value in such a manner that the crane bridge will move straight.
However, the controllers of the prior art control systems will still typically be driven on guide rollers, either inside or outside the bridge and are not able to drive the ends of the crane bridge along a desired truck.
BRIEF SUMMARY OF THE INVENTION
One of the objects of the present invention is to remove the disadvantage mentioned above and thus eliminate the mechanical wear of an apparatus driven on rails.
The objects of the present invention will be attained by providing a system for directing an apparatus, such as a crane bridge, moving on wheels along rails, which apparatus comprises a specified drive arrangement on both sides of a roadway defined by rails, and which system comprises in the apparatus at least on one side of the roadway at least two successive detectors in the direction of the rail for measuring a lateral distance of a specific part of an edge of the apparatus to be driven from the rail, and a control loop guiding the drive arrangements, a controller of the loop being able to direct the distance measurements of the detectors to desired values so that the apparatus to be driven will move straight.
Further, the objects of the present invention will be attained with a control system of the invention that also comprises a second, outer control loop whose controller is able to direct the reference value of the controller of an inner control loop in such a manner that the average of the distance measurements provided by the detectors reaches the desired reference value so that the wheels of the apparatus to be driven will move in the middle of the rails.
One of the basic ideas of the present invention is thus to supplement the control system inner loop by an outer control loop whose controller attempts to direct and turn the apparatus to be driven in such a manner that its ends, i.e. wheels, will always move in the middle of the rail. Therefore, the above-mentioned mechanical wear, which is completely unnecessary but significant, can be stopped altogether.
BRIEF DESCRIPTION OF THE DRAWINGS
Hereinafter, the invention will be explained in more detail in connection with crane bridge driving with reference to the appended drawings which are given by way of illustration only, and thus are not limitative of the present invention, in which:
FIG. 1 shows the basic structure of a crane bridge and components used in driving it,
FIG. 2 shows a block diagram of the basic principle of even driving a crane bridge, and
FIG. 3 shows a block diagram of the control system of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
FIG. 1 shows an upper view of a crane bridge 1 which can be moved on wheels 2 along two rectilinear rails 3 situated at a distance from one another. A trolley to be moved in the transverse direction along the bridge 1 is indicated with reference 4. In this example, there are each time at ends e 1 and e 2 of the bridge 1 two wheels (or two bogies) 2 to both of which a specific motor m 1 , m 2 , m 3 and m 4 has been arranged. That is, there are two motors at both ends e 1 and e 2 of the bridge 1. Specified speed-controlled motor drives k 1 and k 2 have been arranged for the motors m 1 , m 2 , m 3 and m 4 of both ends e 1 and e 2 . The motors m 1 , m 2 , m 3 and m 4 and the motor drives k 1 , and k 2 form in this way specified drive arrangements on both sides of the roadway defined by the rails 3. The span length of the bridge 1 in cranes of this type is generally considerably great. That is, the rails 3 are situated at a distance from one another and thus the distance between the rails of the bridge is considerably greater than the "wheel base" of the bridge. As such, the bridge tends to be driven aslant easily if the speed directions of the motor drives k 1 , and k 2 are not suitably corrected. For this reason, a correction unit 5, typically a PLC (Programmable Logic Controller), is arranged, which in this example controls the motor drives k 1 and k 2 on the basis of the measurement results of detectors d 1 and d 2 arranged to the front and rear sides of one end of the bridge 1. These measurement results represent the lateral distance of a specific part (that is, the location of the detector) of the end of the bridge 1 from the rail 3 in order to inform directly, for example, to what extent the middle line of the wheel 2 is apart from the middle line of the rail 3. Reference 6 indicates guide roller pairs in the front and rear side of the end of the bridge, ensuring that the bridge 1 will remain on the rails. These guide rollers 6, such as detectors d 1 and d 2 , may be positioned only at one end of the bridge, as is shown in this example.
The principle of even driving the bridge 1 will not be described. The distance of the end of the bridge 1 provided with the guide rollers 6 from the rails 3 is measured with the two detectors d 1 and d 2 that can be inductive detectors, for example. On the basis of the obtained measurement information, the motor drives k 1 and k 2 of the bridge 1 are provided with a correction of speed direction. That is, the speeds of the motors m 1 , m 2 , m 3 and m 4 are corrected in such a manner that the end e 1 provided with the detectors d 1 and d 2 and thus the whole bridge will move straight and in the middle of the rails 3. This principle of even driving can be seen in the block diagram of FIG. 2. In FIG. 2:
V ref = reference value of driving speed on bridge given by the user,
I 1 = distance measurement information given by the detector d 1 ,
I 2 = distance measurement information given by the detector d 2 ,
V 1 = the actual speed at the first end e 1 ,
V 2 = the actual speed at the first end e 2 ,
f ref = speed direction for the drives k 1 and k 2 (frequency direction in principle directly through the correction unit 5),
f 1 = correction signals for the drive k 1 , and
f 2 = correction signals for the drive k 2 .
FIG. 3 shows the actual control system and its operation in block diagrams. This control system mainly comprises the correction unit 5 having an outer loop CU with its outer controllers C u and an inner control loop CS with its inner controllers C s . The inner loop controller C s directs the difference of the distance measurement information I 1 and I 2 of the detectors d 1 and d 2 into a desired value. If only the inner loop controller C s is used, this means that the controller C s tries to drive each distance measurement information I 1 and I 2 into the same value. In other words, the bridge 1 tends to move straight on the basis of the measurements.
The difference of the distance measurement information I 1 and I 2 is calculated for the inner loop controller C s in block Fs. A scaling coefficient is preferably added to the calculation to make testing and implementation easier, in which case feedback for the inner loop controller C s is r 1 * (I 1 -I 2 ).
The inner loop controller C s cannot along drive the end e 1 , e 2 of the bridge 1 to the middle of the rail 3, but the end e 1 , e 2 is typically driven on guide rollers 6. In order for the end e 1 , e 2 to remain in the middle of the rail 3, the system is supplemented by an outer loop CU whose controller C u directs the reference value of the inner loop controller C s , trying to turn the bridge 1 in such a manner that the average of the distance measurement information I 1 and I 2 reaches the desired reference value I ref .
The average of the distance measurement information I 1 and I 2 is calculated for the outer loop controller C u as a feedback signal in block F u , in which case feedback for the outer loop controller C u is 0.5*(I 1 , and I 2 ). The outer loop controller C u thus tries to keep the average of the distance measurement information I 1 and I 2 at the reference value I ref .
A fast controller C s should be used in the inner loop CS. It is advisable to choose P (Proportional) controller whose amplification is as high as possible, but low enough so that the controller will not vibrate. A slower controller C u should be used in the outer loop CU. If it is intended that in the balanced state the controller tries to remove a permanent control error, i.e., an integration term, a PI (Proportional Integral) controller should be used in addition to a P controller.
The output u of the control system can be used as such for the motor drives k 1 and k 2 of the bridge as a correction term in such a manner that the correction term will be subtracted from the speed direction of one of the ends e 1 and e 2 of the bridge 1 and correspondingly, the same term is added to the other speed direction. In other words, one end of the bridge 1 is accelerated while the other end is decelerated. The driving direction naturally has an effect on which end speed will be increased and on which will be decelerated.
Instead of conveying the correction term as such to the motor drives k 1 and k 2 , it is often preferable to scale the correction term according to the actual drive speed v 1 and v 2 at the ends e 1 and e 2 . In addition, it is in practice advantageous to filter the correction term to avoid torque strikes. These operations are carried out in block G. Scaling takes place so that on small driving speeds, the speed corrections of the ends e 1 and e 2 are small and when the driving speed increases, the speed corrections will correspondingly grow as well when necessary. One way is to scale the correction term linearly as a function of the actual driving speed. Another way is to tabulate scaling according to the driving speed.
In addition, it should be noted that the correction term must not pass through the ramp generator of the motor drive k 1 and k 2 , but the correction term has to be associated with the speed direction that is conveyed to the speed controllers of the motor drive k 1 and k 2 . If the correction is added before the ramp generator, the controller C s and C u will not have any effect during acceleration and deceleration.
The sign of the correction term conveyed to the motor drives k 1 and k 2 depends on the moving direction. When the driving direction of the bridge 1 changes, the sign of the correction term will also change. Similarly, the sign of the output of the outer loop CU depends on the driving direction of the bridge 1. The output of the outer loop CU, that is, the reference value of correction will change when the driving direction of the bridge 1 varies in such a manner that the controller C u tries to drive the bridge 1 in a difference way aslant when the driving direction changes so that the end e 1 and e 2 could be taken to the middle of the rail 3.
Because a reasonable speed is required of the inner loop controller C s , measurements cannot be filtered too fast. Filtering which is too strong will make the controller C s vibrate. On the other hand, the outer loop controller C u filtered to be slower will tolerate more filtering of measurements. It may often be sensible to filter the measurements of the outer loop controller C u stronger than the measurements of the inner loop controller C s , in which case the outer loop CU will act in a more unperturbed way.
Other controllers, such as a PI controller, can also be used as the inner loop controller C s in the place of a P controller. Similarly, the outer loop controller C u can be other than a PI controller. Furthermore, by changing the parameters of the control system, only the inner loop controller C s can be selected to be active, in which case the system tries to run the difference between the measurements to zero, as was said earlier. In exactly the same way by the selection of parameters, only the outer loop controller C u can be made active, whereby the control system tends to run the average of the measurements to the desired reference value irrespective of whether the bridge 1 will move straight. It depends on the application which of these alternatives will in practice produce the best result.
The explanation of the invention above is only intended to illustrate the invention. In its details, the invention may vary considerably in the scope of the accompanying claims. It should also be noted that the invention may be applied not only in connection with crane bridges but also in connection with other apparatuses driven on rails. | The invention relates to a system for directing an apparatus, such as a crane bridge (1), moving on wheels along rails, which apparatus comprises a specified drive arrangement (m 1 , m 2 , m 3 , m 4 ; k 1 , k 2 ) on both sides of a roadway defined by rails (3), and which system comprises in the apparatus at least on one side of the roadway at least two successive detectors (d 1 , d 2 ) in the direction of the rail (3) for measuring a lateral distance (l 1 , l 2 ) of a specific part of an edge (e 1 , e 2 ) of the apparatus to be driven from the rail, a control loop (CS) guiding the drive arrangements, a controller of the loop being able to direct the distance measurements (l 1 , l 2 ) of the detectors (d 1 , d 2 ) to desired values so that the apparatus to be driven will move straight, and an outer control loop (CU) whose controller is able to direct the reference value of the controller of the inner control loop in such a manner that the average of the distance measurements (l 1 , l 2 ) provided by the detectors (d 1 , d 2 ) reaches the desired reference value so that the wheels (2) of the apparatus to be driven will move in the middle of the rails (3). | 1 |
[0001] This application is a divisional application from U.S. patent application Ser. No. 14/931,236, filed Nov. 3, 2015, currently pending, which is a divisional application of Ser. No. 13/435,260, filed Mar. 30, 2012, currently pending, from which priority is claimed.
BACKGROUND OF THE INVENTION
[0002] There are several inventions and efforts to produce graphene chemically, thermally, and mechanically. Exfoliation involves the removal of the layers on the graphite's outermost surface. Ball milling is the most used of these methods, and this method involves milling the graphene in a closed container using various milling media. The ball mill moves in only one direction, that is, rotational on a horizontal axis. Prior art methods have described the results, however, they have failed to describe the specific mechanical forces in type and size, and the system of components required for success.
[0003] The applicant is aware of WO2011006814 that deals with a wet process for providing particulate materials.
BRIEF DESCRIPTION OF THE INVENTION
[0004] The instant invention, in one embodiment, deals with an apparatus that includes a system of components to mechanically exfoliate particulate materials using a multi-axis approach. In this embodiment, layers of particulate material or multilayer material are removed via a controlled shear by using a mechanical movement.
[0005] The apparatus of this invention includes a machine to deliver forces, containers to hold particulate material and media, the media, and the associated parameters for operating such equipment along with, methods and compositions provided by the apparatus and methods.
[0006] Thus, what is claimed in one embodiment, is an apparatus for mechanically exfoliating particulate material with a basil plane, said apparatus comprising in combination a support frame, a motor mount, a motor mounted on the motor mount, the motor having a drive shaft, wherein the drive shaft has a driven flywheel mounted on it.
[0007] The support frame has a non-stationary plate surmounted on it by mounted shock absorbers. The non-stationary plate has a front end and a back end, and it has a non-stationary plate rigidly surmounted on it.
[0008] There is a processor assembly comprising a main drive shaft having two ends extending through drive shaft mounts, the main drive shaft comprising a flywheel between the ends of the main drive shaft.
[0009] There is one or more cams on the main drive shaft, and a fastening means on each end of the main drive shaft to maintain the main drive shaft in the drive shaft mounts.
[0010] There is a canister carrier mounted on each cam, the canister carrier comprising a hub, wherein the hub has an external surface mounted cradle and an internal flat surface supporting bearings.
[0011] There is a stabilizer drive mechanism, the stabilizer drive mechanism comprising a ring gear driven by a pinion gear, a secondary drive shaft surmounted on the non-stationary flat plate. The secondary drive shaft is mounted in secondary drive shaft mounts and surmounted on the non-stationary flat plate.
[0012] The secondary drive shaft has at least three first drive wheels. There is a drive link connecting each first drive wheel with an aligned second drive wheel.
[0013] In addition, there is an embodiment which is an apparatus for mechanically exfoliating particulate material, the apparatus comprising in combination a support frame. The support frame is comprised, of an upper bar frame and a lower bar frame, wherein the upper bar frame and lower bar frame are supported by vertical legs. The upper bar frame and lower bar frame are parallel and spaced apart from each other.
[0014] There is a motor mount mounted on and supported by the lower bar frame and there is a motor mounted on said motor mount, the motor having a drive shaft and the drive shaft having a driven flywheel mounted on it.
[0015] The upper bar frame has a non-stationary plate surmounted thereon by at least four corner mounted shock absorbing mounts. The non-stationary plate has a front end and a back end. The non-stationary plate has rigidly surmounted on it, drive shaft mounts. The non-stationary plate has two large openings on either side of a smaller centered opening and the drive shaft mounts are located on the outside edges of the large openings.
[0016] There is a processor assembly compiling: a main drive shaft having two ends extending through all drive shaft mounts. The main drive shaft comprises a flywheel centered between the ends of the main drive shaft. There are two cams, each centered between the flywheel and an end of the main drive shaft, and a fastening means on each end of the main drive shaft to maintain the main drive shaft in the drive shaft mounts.
[0017] There is a canister carrier mounted on each cam, the canister carrier comprising: a hub, wherein the hub has an external surface mounted cradle and an internal flat surface supporting bearings, there being mounted on an outside hub, a drive component such as a stabilizer ring gear. There is rotatably mounted on the main drive shaft, adjacent to the stabilizer ring gear, a stabilizer housing, the stabilizer housing containing internal bearings adjacent to the main drive shaft, wherein there is a stabiliser pinion gear surrounding the stabiliser housing and meshing with the stabilizer ring gear.
[0018] There is a stabilizer drive mechanism, the stabilizer drive mechanism comprising a secondary drive shaft surmounted on the non-stationary flat plate near the backend. The secondary drive shaft is mounted in secondary drive shaft mounts, surmounted on the non-stationary flat plate. The secondary drive shaft has at least three first drive wheels, one each near an end of the secondary drive shaft and one centered on the secondary drive shaft.
[0019] The main drive shaft has at least three second drive wheels, each being aligned with second end first drive wheels on the secondary drive shaft, the centered first drive wheel being aligned with a third drive wheel mounted on a gear reducer. The gear reducer is surmounted on the non-stationary flat plate between the flywheel and the secondary shaft. The gear reducer has a fourth drive wheel mechanically connected to a third drive wheel by reducing gears, the fourth drive wheel and centered first drive wheel are connected by a drive link, the drive link connecting each of the first drive wheel with an aligned second drive wheel.
[0020] In another embodiment, there is an apparatus for mechanically exfoliating particulate material, the apparatus comprising in combination: a support frame. The support frame is comprised of an upper bar frame and a lower bar frame, wherein the upper bar frame and lower bar frame are supported by vertical legs. The upper bar frame and lower bar frame are parallel and spaced apart from each other.
[0021] There is a motor mount mounted on and supported by the lower bar frame and there is a motor mounted on said motor mount, the motor having a drive shaft and the drive shaft having a driven flywheel mounted on it.
[0022] The upper bar frame has a non-stationary plate surmounted thereon by at least four corner mounted shock absorbing mounts. The non-stationary plate has a front end and a back end. The non-stationary plate has rigidly surmounted on it, drive shaft mounts. The non-stationary plate has two large openings on either side of a smaller centered opening and the drive shaft mounts are located on outside edges of the large openings.
[0023] There is a processor assembly comprising: a main drive shaft having two ends extending through all drive shaft mounts. The main drive shaft comprises a flywheel centered between the ends of the main drive shaft. There are two cams, each centered between the flywheel and an end of the main drive shaft, and a fastening means on each end of the main drive shaft to maintain the main drive shaft in the drive shaft mounts.
[0024] There is a canister carrier mounted on each cam, the canister carrier comprising: a hub, wherein the hub has an external surface mounted cradle and an internal flat surface supporting bearings, there being mounted on an outside hub, a stabiliser ring gear. There is rotatably mounted on the main drive shaft, adjacent to the first stabilizer wheel, a stabilizer housing, the stabilizer housing containing internal bearings adjacent to the main drive shaft, wherein there is a second stabilizer wheel surrounding the stabilizer housing and meshing with the first stabiliser wheel.
[0025] There is a stabilizer drive mechanism, the stabilizer drive mechanism comprising a secondary drive shaft surmounted on the non-stationary flat plate near the backend. The secondary drive shaft is mounted in secondary drive shaft mounts, surmounted on the non-stationary flat plate. The secondary drive shaft has at least three first drive wheels, one each near an end of the secondary drive shaft and one centered on the secondary drive shaft.
[0026] The main drive shaft has at least three second drive wheels, each being aligned with second end first drive wheels on the secondary drive shaft, the centered first drive wheel being aligned with a third drive wheel mounted on a gear reducer. The gear reducer is surmounted on the non-stationary flat plate between the flywheel and the secondary shaft. The gear reducer has a fourth drive wheel mechanically connected to a third drive wheel by reducing gears, the fourth drive wheel and centered first drive wheel are connected by a drive link, the drive link connecting each of the first drive wheel with an aligned second drive wheel.
[0027] In yet another embodiment, there is a drive shaft. The drive shaft is integral and comprises a linear shaft having two terminal ends and a center point. The linear shaft has fixedly mounted at the center point, a flywheel. There are two cams, each cam having a near end and a distal end. Each cam has an opening through it whereby the opening begins at the near end near a bottom edge of the cam, and terminates through the distal end near a top edge. The linear shaft extends through the opening in the cam and extends beyond the distal end of the cam. The drive shaft has mounted on it, a wheel drive adjacent to the flywheel.
[0028] In still another embodiment of this invention there is a ring gear. The ring gear comprises: an inside surface and an outside surface, the inward surface is comprised of a plurality of gear teeth, the number and shape of gear teeth being matched to mesh with a corresponding gear on an adjacent pinion gear.
[0029] A further embodiment is a cam assembly comprising a cylindrical housing. The cylindrical housing has a near end and a distal end and an opening extending from the near end through the distal end. The opening begins at the near end of the cam and near a bottom edge and terminates through the distal end near a top edge, the distal end having an off round, at least one said end cap having a valve inserted therein
[0030] Yet another embodiment is a carrier assembly for canisters. The carrier assembly comprises a hubbed housing having an open center through it with an internal surface. The hub has at least two bearings mounted on the internal surface of the housing and internal to each hub. The hubs support an integral canister cradle attached to the hubs. One hub has a stabilizer ring gear fixedly attached thereto such that the gear face of the gear faces away from the hub.
[0031] In yet another embodiment, there is in combination a carrier assembly and at least one canister.
[0032] There is a canister embodiment, the canister comprising: a hollow cylinder having two terminal ends, each of the terminal ends having a scalable cap mounted thereon. There is at least one end cap having a valve inserted therein.
SUMMARY DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a top view in perspective of the apparatus of this invention.
[0034] FIG. 2 is a full top view of the apparatus of this invention.
[0035] FIG. 3 is a full front view of the apparatus of this invention.
[0036] FIG. 4 is a full end view of the apparatus of this invention from the end opposite the motor.
[0037] FIG. 5 is a full end view of the apparatus of this invention from the motor mount end.
[0038] FIG. 6 is a full side view of a main drive shaft of this invention with its component parts.
[0039] FIG. 7 is a view in perspective of the main drive shaft of FIG. 6 .
[0040] FIG. 8 is a full side view of a cam of this invention.
[0041] FIG. 9 is a full end view of a cam of this invention showing the rectangular inset and opening therethrough.
[0042] FIG. 10 is a view in perspective of the cam of FIG. 8 .
[0043] FIG. 11 is a cross sectional view of the cam of FIG. 9 , through line A-A.
[0044] FIG. 12 is a partial cross section of the canister carrier mounted on a cam.
[0045] FIG. 13 is an end view of a canister carrier showing the canister cradle mounted with canisters and an end view of a ring gear.
[0046] FIG. 14 is a full side view of the canister carrier of FIG. 13 .
[0047] FIG. 15 is a view in perspective of the canister carrier of FIG. 13 .
[0048] FIG. 16 is a another embodiment of the stabilizer assembly of this invention using rubber wheels.
[0049] FIG. 17 is a full end view of a ring gear on this invention.
[0050] FIG. 18 is a full edge view of the ring gear of FIG. 17 .
[0051] FIG. 19 is a view in perspective from the front, of the ring gear of FIG. 17 .
[0052] FIG. 20 is a full back view of a pinion gear on this invention.
[0053] FIG. 21 is a full side view of the pinion gear of FIG. 20 .
[0054] FIG. 22 is a full view in perspective of the back of the pinion gear of FIG. 20 .
[0055] FIG. 23 is a top view of the secondary drive assembly mounted on the flat plate.
[0056] FIG. 24 is an end view of the drive assemblies of FIG. 23 .
[0057] FIG. 25A is an illustration of the axis 1 orbital rotation of the canisters when the apparatus is in motion.
[0058] FIG. 25B is an illustration of the axis 2 orbital rotation of the canisters when the apparatus is in notion.
[0059] FIG. 25C is an illustration of the planar axis 2 translation and the planar axis 1 translation of the canisters when the apparatus is in motion.
[0060] FIG. 25D is an illustration of the planar axis 3 translation of the canisters when the apparatus is in motion.
[0061] FIG. 26 is a full side view of one canister design of this invention.
[0062] FIG. 27 is partial enlarge view of the stabilizer assembly.
[0063] FIG. 28 is a full side view of a synchronous drive of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0064] Turning now to FIG. 1 , there is shown a full top view in perspective of the apparatus 1 of this invention. FIG. 2 is a full top view of the apparatus, FIG. 3 is a full front view of the apparatus, and FIG. 4 is a full end view of the apparatus of this invention from the end opposite of the motor mounting. The Figures should be consulted for an understanding of the information that follows.
[0065] In FIGS. 1, 3, and 4 , there is shown a framework 2 for supporting the working components of this invention and thus there is shown the legs 3 of the framework 2 , the upper bar frame 4 , and a lower bar frame 5 .
[0066] With reference to FIG. 5 , there is shown a motor mount 6 , mounted on the lower fear from 5 , on which there is mounted a motor 7 , also shown in FIG. 3 more clearly. The motor 7 is the main drive mechanism for the apparatus 1 . The motor has a motor drive shaft 8 , shown in FIG. 4 , and attached to this drive shaft 8 is a driven flywheel 9 .
[0067] As shown clearly in FIGS. 1, 2, and 3 , the upper bar frame 4 has a non-stationary flat plate 10 surmounted on it which is supported at least at each of the four corners 11 , by shock absorbing mounts 12 . The non-stationary flat plate 10 has a front end 13 and a back end 14 (shown in FIG. 5 ). Rigidly mounted on the flat plate 10 are drive shaft mounts 15 , which hold the main drive shaft 16 which will be discussed in detail infra. The drive shaft mounts 15 are located on either side of a small opening discussed infra and on either side of the two larger openings 18 , also discussed infra.
[0068] The flat plate 10 has a centered small opening 17 and two larger openings 18 on either side of the centered small opening 17 . Located in the two large openings 18 are processor assemblies 19 , both processor assemblies being supported and driven by the main drive shaft 16 , which extends from the drive shaft mount 15 on one edge of the flat plate 10 to the drive shaft mount 15 on the opposite edge of the flat plate 10 .
[0069] There is centered on the main drive shaft 16 , a main flywheel 20 , which main flywheel 20 is essentially suspended by the main drive shaft 16 in the small opening 17 . Thus, the processor assemblies 19 consist of the main drive shaft 16 and the main flywheel 20 .
[0070] Turning now to FIGS. 6 and 7 , there is shown the details of the main drive shaft 16 . FIG. 6 is a full side view and FIG. 7 is a full view in perspective. The main drive shaft consists of a straight shaft 21 on which are mounted the main flywheel 20 , centered between the ends 22 of the straight shaft 21 , two cams 23 each spaced essentially equidistant between the main flywheel 20 and the ends 22 of the straight shaft 21 . Also shown are the fasteners 23 for fastening the main drive shaft 16 in the drive shaft mounts 15 (not shown in FIGS. 6 and 7 ). One preferred drive mechanism for the main drive shaft is shown as a chain sprocket 24 .
[0071] The cams 23 are shown in detail in FIGS. 8, 9, 10, and 11 . The cam comprises a solid cylinder 31 , that has one flat end 32 and the opposite end 33 configured at a slight angle Θ from the vertical, said angle Θ comprising less than about 15°. ( FIG. 8 is a full side view of the cam 23 of this invention). It should be noted that end 33 also has a slight hub associated with that end. In observing FIGS. 9 and 10 , there is shown an opening 34 , which is rectangular in configuration, through which the straight shaft 21 of the main drive shaft 16 extends. Note from FIG. 11 , that the opening 34 has an inset 35 , and that the remainder of the opening 34 is angled through the cam 23 . By this means, the straight shaft 21 , when the main drive shaft 16 tarns, causes the canister carrier 26 attached to it to move in an irregular motion as will be described in detail infra.
[0072] There is a canister carrier 26 mounted on each cam 23 (see FIGS. 12, 13, 14, 15, and 16 . The canister carrier 26 can carry one or more canisters 27 as shown in FIGS. 13, 14, 15 , and 16 . As the cams 23 move, the canister carriers 26 move. The canister carriers 26 have an outside hub 28 ( FIG. 12 ), wherein the outside hub 28 has an external surface mounted cradle 29 . The outside hub 28 has an internal flat surface 37 supporting bearings 30 .
[0073] The canisters can be fabricated from any material that will sustain the forces and not contaminate the material in the canister. Such useable materials include, for example, stainless steel, plated steel, polycarbonate, aluminum and titanium, among others.
[0074] There is a mounted on the outside hub 28 , a stabilizer assembly in one embodiment, consisting of a pinion gear 36 FIGS. 20, 21, and 22 , and a ring gear 38 , FIGS. 17, 18, and 19 , and in another embodiment, a stabiliser ring 39 and a stabiliser wheel 40 (See FIG. 16 ).
[0075] There is rotatably mounted on the main drive shaft 16 , adjacent to the stabilizer ring gear 38 (or stabilizer ring 39 in the event of another embodiment), a stabiliser housing 42 . The stabilizer housing 42 contains internal bearings 43 adjacent to the main drive shaft 16 . It should be noted that the pinion gear 36 surrounds the stabilizer housing 42 and from this position meshes with the ring gear 38 , (See FIG. 12 ).
[0076] The ring gear 38 comprises an inward surface 44 and an outside surface 45 . The inward surface 44 is comprised of a plurality of gear teeth 46 , the number and shape of gear teeth 46 being matched to mesh with corresponding teeth on the adjacent pinion gear 36 . It will be noted from FIGS. 17 and 19 that the gear teeth 46 slant forward within the ring gear 28 .
[0077] Turning now to FIGS. 20, 21, and 22 , there is shown a pinion gear 36 which operates in conjunction with the ring gear 38 . Note that the teeth 47 on the pinion gear 36 are configured to mesh with the gear teeth 46 of the ring gear 38 .
[0078] There is a stabilizer drive mechanism 48 , best shown in FIGS. 2 and 23 and 24 , that is comprised of a secondary drive shaft 49 that is surmounted on the non-stationary flat plate 10 , near the backend of the plate 10 . The secondary drive shaft 49 is mounted in secondary drive shaft mounts 50 , three of which are shown in FIG. 23 , said mounts 50 being mounted on the flat plate 10 . The secondary drive shaft 49 has at least three first drive wheels 51 , one near each near end of the secondary drive shaft 49 and one essentially centered on the secondary drive shaft 49 .
[0079] The main drive shaft 16 has at least three second drive wheels 52 being aligned with the second end first drive wheels 51 on the secondary drive shaft 49 . The centered first drive wheel 52 is aligned with a third drive wheel 54 mounted on a gear reducer 53 shown in FIG. 23 . The gear reducer 53 is surmounted on the non-stationary flat plate 10 between the driven flywheel 9 and the secondary shaft 39 . The gear reducer 53 has a fourth drive wheel 55 mechanically connected to a third drive wheel 54 by reducing gears (not shown). The fourth drive wheel 55 and centered first drive wheel 52 being connected by a drive link 56 shown in FIG. 5 . There is a second drive link 57 connecting each first drive wheel 51 with an aligned second drive wheel 52 .
[0080] FIG. 28 is a side view of the canister 58 mounted in the canister carrier 26 . This Figure shows an enlarged view of the mechanism for stabilization, namely, the cam 23 , the bearings 30 on the cam, the stabilizer ring 38 , the stabilizer hub 28 , a drive link 57 which is a belt drive, the stabilizer bearing 43 , and the main drive shaft 16 . Canister sizes can ranged from 12 to 15 inches in length and from 4 to 8 inches in diameter.
[0081] In this manner of linking the drive wheels, in operation, the main drive shaft 16 moves in a counter clockwise rotation and the secondary drive shaft 49 for the stabilizer units moves in a clock wise rotation. Due to the gearing mechanism 53 , the secondary drive shaft 49 moves much slower than the main drive shaft 16 .
[0082] It is contemplated within the scope of this invention to substitute a synchronous drive unit for the secondary drive mechanism that drives the secondary shaft.
[0083] FIG. 26 shown a full side view of one canister 27 design of this invention wherein there is shown the canister 27 , the cap 60 and the atmosphere control valve 62 .
[0084] Turning now to another embodiment of a stabilizer drive mechanism of this invention, there is shown in FIG. 28 a full side view of a synchronous drive 63 mounted on the non-stationary plate 10 . The synchronous drive 63 is comprised of a belt system comprising a drive belt 64 that is attached to a drive wheel 65 and linked to a second wheel 66 , which is mounted on the secondary shaft 49 (shown in FIG. 1 ). It should be noted from the arrows in FIG. 28 that the main drive shaft 16 drives in a counter clockwise motion, and the secondary drive shaft 49 drives in a clockwise motion.
[0085] The apparatus 1 is designed to impart forces in three planes and in orbital planes, one, two, or three, simultaneously (see FIGS. 25A to 25D ). FIG. 25A shows the axis 1 orbital rotation. FIGS. 25B shows the axis 2 orbital rotation. FIG. 25C shows the planar axis 2 translation in the vertical direction and the planar axis 1 translation in the horizontal direction. FIG. 25D shows the planar axis 3 translation.
[0086] The apparatus acts on the media to translate it in all planes simultaneously. By doing so, the energy of the apparatus is converted into the stress state required to cause the exfoliation of the particulate material. Other methods of milling, grinding, or size reduction of particulates do not impart forces or translate the media in these planes simultaneously. Most typically, these machines affect only 2 or 3 planes, or e places and I orbital t most. The theory of these methods or machines is to move the media so that the media can do the work. This causes pulverization to occur. The operation of conventional machines does not create the correct stress environment to allow exfoliation to occur.
[0087] In addition to creating exfoliation via the shear forces, the present invention creates wear rate or deterioration on the media is minimized due to the machine doing the work and not the media. The apparatus of the instant invention moves the media so that the media and the apparatus act as one unit and are not disassociated.
[0088] The milling media is chosen so that it provides optimum mass and provides correct shear forces. The mass is determined by the specific gravity of the media. If the specific gravity becomes too large, the forces that occur as the media comes into contact with the particulate material will exceed the shear thresholds and becomes tensile or compressive in nature. Should the forces become tensile or compressive, pulverization occurs. If the specific gravity of the media becomes too small, the forces that occur as the media comes into contact with the particulate material will offer limited effect.
[0089] The shear forces are determined by the inter facial surface energy of the media. If the interracial surface energy with respect to the material being exfoliated becomes too large the forces that occur as the media comes into contact with the particulate material will exceed the shear thresholds and become tensile or compressive in nature. The performance of the apparatus is optimized as the interfacial surface energy and the surface area (achieved via diameter) is optimized. Media of mixed diameter may be used, if the surface energy between the media and material being exfoliated is too low, the media slips on the surface of the material and does not apply sufficient shear to cause exfoliation.
[0090] In order for the machine and the media to act as one unit and create exfoliation, the cavity and the amount of fill of media in the cavity must be correct. The cavity must be filled in proportion to the length of movements created by the planar vectors. The performance of the apparatus is improved as the fill ratio, L overall to L void is optimised.
[0091] In the method of this invention, wherein the apparatus 1 is used, it is necessary to cause the shear forces (or energy) created to be high enough in the basal plane that fracture (potential energy increase) will predominately occur in those planes prior to fracture through tensile forces. Based on test results, the following best describes the conditions under which the apparatus should be operated.
[0092] The ratio of mass of media to mass of particulate should be in the range of 1:6 to 1:15; the height of media to height of canister should be 60 to 90%; the free space to canister displacement should be less than 40%; the specific gravity of the media should be from 1.05 to 1.38. Preferred for this apparatus and method is plastic media, although other known exfoliating media can be used as long as it fits the parameters of use in this invention, namely, the media is chosen to match the specific surface energy of the particulate. The actual operating time should be in the range of 45 minutes to about 1200 minutes.
[0093] The composition of matter that is a produced by this apparatus and method can be any particulate material, or any combination of particulate material. The preferred particulate material is one that has basal planes and exfoliates to form platelets. Preferred particulate matter for this method is graphite exfoliated into graphene nanoplatelets. The particulate material is preferred to be high surface area graphene nanoplatelets comprising particles ranging in sire from 1 nanometer to 5 microns in lateral dimension and consisting of one to a few layers of graphene with a z-dimension ranging from 0.3 nanometers to 10 nanometers and exhibiting very high BET surface areas ranging from. 200 to 1200 m 2 /g. In some embodiments partially exfoliated particulate matter with a BET surface area from 30 to 200 m 2 /g may be produced.
[0094] The apparatus may be capable of containing one or multiple containers. It may provide for more than one centroid of movement from one driver motor. | Apparatus to deliver predetermined forces, containers to hold particulate material and media, media, and the associated parameters for operating such equipment along with methods and compositions provided by the apparatus and methods. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to electronic smoke apparatus (or electronic smoke in short), and more particularly to electronic cigarettes. The present invention also relates to air-flow rate and direction detector for use in an electronic smoke apparatus.
BACKGROUND OF THE INVENTION
[0002] Electronic smoke apparatus such as electronic cigarettes provide a smoking alternative to smokers. An electronic smoke is a non-naked flame smoking apparatus which typically comprises a battery powered heater arranged to vaporize liquid nicotine or nicotine substitutes upon actuation by a user. The heater is usually automatically actuated by a controller when a user inhales through the electronic smoke to simulate a smoking action. Typically, an inhaling detector is provided in an electronic smoke and the controller, such as a digital signal processor (DSP) will actuate the heater when inhaling is detected by the inhaling detector. An exemplary equivalent application circuit of a conventional electronic cigarette is shown in FIG. 1 .
[0003] The inhaling detector of a conventional electronic smoke apparatus typically comprises an air-flow sensor having a structure similar to that of a conventional microphone condenser of FIG. 2 . A typical air-flow sensor of a conventional electronic smoke comprises a variable capacitor (Cs) comprising a membrane and a back plate, a pre-charged electret layer (Vs), and a junction field effect transistor (JFET) arranged as schematically shown in FIG. 2 . The DSP of the smoking circuitry is arranged to actuate the heater automatically when vibration, which is assumed to be due to inhaling, is detected by the air-flow sensor. However, such an arrangement is not very reliable since false actuations are common, especially in a noisy environment. Furthermore, the structure of a conventional air-flow sensor is relatively complicated and more expensive, since a JFET stage is required to amplify signals detected by the vibrating membrane and an electret layer is in combination with a back plate to form a reference capacitive surface.
[0004] Therefore, it would be advantageous if an improved air-flow sensor for an electronic smoke could be provided.
[0005] In this specification, the terms electronic smoke and electronic smoke apparatus are equivalent and includes electronic smoke apparatus which are commonly known as electronic cigarettes, electronic cigar, e-cigarette, personal vaporizers etc., without loss of generality.
SUMMARY OF INVENTION
[0006] According to the present invention, there is provided an electronic smoke comprising an inhale detector and a smoke effect generating circuitry, wherein the inhale detector comprises an air-flow sensor which is arranged to detect direction and rate of air flow through the smoke apparatus, and wherein the smoke effect generating circuitry is arranged to operate the smoke effect generating circuitry to generate smoking effect when the air flow direction corresponds to inhaling through the apparatus and the air flow rate reaches at predetermined threshold. Such an electronic smoke alleviates the problem of inadvertent triggering due to environmental vibration or noise or children playing by blowing into the device.
[0007] In an embodiment, the air-flow sensor may comprise an air-baffle surface which is adapted to deform in response to movement of air through the apparatus, the extent of deformation of the air-baffle surface being measured to determine both the direction and rate of air flow through the apparatus. Measure of deformation within a predetermined period of time further mitigates the risk of inadvertent triggering due to vibrations or environmental noise.
[0008] As an example, the capacitance or the change in capacitance of the air-flow sensor may be measured to determine the extent of deformation of the air-baffle surface.
[0009] In an embodiment, the smoke effect generating circuitry may comprise a processor which is adapted to measure the capacitance or change in capacitance of the air-flow sensor. As a controller or processor is usually require to operate the heater of the smoke, measuring the capacitance or change in capacitance by the processor means an unexpected cost effective solution.
[0010] As a further example, the air-flow sensor may form part of an oscillator circuit, and the processor is arranged to measure the oscillation frequency of the oscillation circuit to determine the air-flow rate and direction. As the oscillation frequency of an oscillator circuit, especially an LC oscillator circuit, is dependent on the capacitance value, this provides a cost effective solution to provide a low cost and compact solution.
[0011] As an example, the predetermined threshold of air flow rate may correspond to the flow rate of a typical smoke inhaling action by a user through the apparatus. This would operate to prevent triggering of the smoke generating circuitry by mischief or accidental vibration or noise.
[0012] In an embodiment, the air-flow sensor may comprise a conductive air baffle surface which is spaced apart from a base conductive surface, and the air baffle surface is adapted to deform in response to air flow through the apparatus; characterized in that the variation in capacitance between the baffle surface and the base surface is indicative of the direction and rate of air flow.
[0013] In another aspect of the present invention, there is provided an air-flow rate and direction detector comprising an air-flow sensor and a controller, wherein the air flow sensor comprises a baffle surface which is adapted to deform in response air flow, and the controller is adapted to determine the air-flow rate and direction with reference to the extent of deformation of the baffle surface.
[0014] The controller of the detector may be adapted to determine the air-flow rate and direction with reference to the capacitance or variation of capacitance of the air-flow sensor.
[0015] The controller may comprise an oscillation circuit, and the air-flow rate sensor forms part of the oscillator circuit; characterized in that the controller is adapted to determine the air-flow rate and direction with reference to the oscillator frequency or variation in oscillator frequency of the oscillator.
[0016] The detector may be adapted for use in electronic cigarettes or smoke for heater triggering, or in articles operated by suction- or blowing, such as wind-blow instruments like electronic recorders or toys.
BRIEF DESCRIPTION OF FIGURES
[0017] Embodiments of the present invention will be explained below by way of example with reference to the accompanying drawings, in which:—
[0018] FIG. 1 is a schematic equivalent circuit diagram of an actuation circuit of a conventional electronic smoke,
[0019] FIG. 2 is a schematic diagram of an air-flow sensor typically used in a conventional electronic smoke,
[0020] FIG. 3 is a schematic diagram of an actuation circuit of an electronic smoke according to an embodiment of an electronic smoke of the present invention,
[0021] FIG. 4 is a schematic diagram of an air-flow sensor for an electronic smoke according to an embodiment of the present invention,
[0022] FIG. 5 shows an exemplary relationship between capacitance and air-flow rate of the air-flow sensor of FIG. 4 ,
[0023] FIGS. 6A , 6 B and 6 C are schematic diagrams illustrating the air-flow sensor of FIG. 4 in standby mode (no air flow), under inhaling condition (suction), and under exhaling condition (blowing) respectively,
[0024] FIG. 7 is a schematic equivalent circuit diagram of an embodiment of an electronic smoke according to the present invention, and
[0025] FIG. 8 is a schematic diagram illustrating an exemplary embodiment of an electronic smoke of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0026] The electronic cigarette ( 10 ) as an example of an electronic smoke as shown in FIG. 8 comprises an inhale detector ( 100 ) as an example of an air-flow rate and direction detector, a battery ( 200 ) as an example of stored power source, a nicotine source as a example of a smoke or favor (or aroma) source, and a heating element ( 300 ) as a heating means. The inhale detector, the battery and the heating element are all housed within a main housing ( 400 ) which comprises a first tubular portion ( 420 ) in which the battery and the inhale detector are mounted, a second tubular portion ( 440 ) in which the heating element and the nicotine source are mounted, and a third tubular portion ( 460 ) containing a mouth piece ( 462 ). In addition, a transparent or translucent cover ( 500 ) is attached to the downstream end of the first tubular portion.
[0027] The inhale detector is a modular assembly comprising an air-flow sensor ( 120 ), an actuation circuit and an LED light source ( 130 ), which are all mounted on a printed circuit board ( 140 ). Referring to FIG. 4 , the air-flow sensor comprises a rigid or semi-rigid conductive membrane ( 121 ), such as a metallic sheet which are mounted above a conductive back plate ( 122 ) in a spaced apart manner and separated by an insulating spacer ( 123 ). The sub-assembly comprising the conductive membrane and the conductive back plate arranged in a spaced apart and substantially parallel manner forms a capacitive component, the instantaneous capacitance value or variation in capacitance value of which will be utilized in a manner to be discussed in more detail below.
[0028] As the conductive will need to respond rapidly to repeated inhaling and to return to its neutral or standby condition quickly or immediately after inhaling stops, a metallic sheet having a good axial resilience property is preferred to be used as the conductive membrane. The conductive back plate is connected to an earth plate ( 124 ), which is in turn mounted on a PCB, by a conductive ring ( 125 ) to form a reference ground of the capacitive component. This sub-assembly of the air-flow sensor and PCB is housed within a metallic can ( 126 ) which defines an air inlet and an air outlet at its axial ends.
[0029] The capacitive properties of the air-flow sensor of FIG. 4 would be readily apparent from the schematic representations of FIGS. 6A to 6C . The schematic diagram of FIG. 6A shows the air-flow sensor when there is no or negligible air flow through the sensor. In this condition, the conductive membrane and the conductive back plate are substantially parallel with a separation distance d. The capacitive value of the sensor in this stand-by or rest condition is given by the relationship C=∈A/d, where C is the capacitance, ∈ is the dielectric constant of the spacing medium, and is the overlapping surface area between the conductive membrane and the back plate. As an example, the capacitance value of a sensor with a diameter or 8 mm and a separation of 0.04 mm is about 10 pF.
[0030] When air flows through the air-flow sensor in the direction as shown in FIG. 6 B, suction due to the air flow will cause the resilient metallic membrane to bulge away from the back plate. As the separation (d) between the metallic membrane and the back plate increases in general under this condition, the capacitance value of the air-flow sensor will decrease in response to air flow in this direction.
[0031] On the other hand, when air flows in an opposite direction as shown in FIG. 6B , the resilient membrane is caused to deflect towards the back plate. As the separation distance between the metallic membrane and the back plate will decrease in general in this condition, the capacitance value will increase in response to air flow of this direction.
[0032] In ether cases, the resilience of the metallic membrane will return the membrane to the neutral condition of FIG. 6A when the air flow stops or when the air-flow rate is too low to cause instantaneous deflection or deformation of the metallic membrane. An exemplary variation of capacitance value of the air-rate sensor in response to air flow in the direction of FIG. 6B is shown in FIG. 5 .
[0033] An application of the air flow sensor of FIG. 4 is depicted in an exemplary circuit of FIG. 7 . Referring to FIG. 7 , the air-flow sensor (marked CAP) is connected to a capacitance value measurement unit ( 150 ). The result of the capacitance value is transmitted to a microcontroller ( 160 ). If the result of the capacitance value measurement corresponds to a suction action of a sufficient air-flow rate, the microcontroller will send an actuation signal to operate the heater to cause vaporization of the nicotine stored in a nicotine pool. The nicotine vapor will be inhaled by a user through the mouth piece as a result of the inhaling action. The heater is connected to the BAT terminal of the circuit of FIG. 7 . In addition, the actuation signal will also operate an LED driver ( 170 ) to operate an LED light source to provide a smoking indicator as a decoration.
[0034] To provide a simplified capacitance measurement arrangement, a digital signal processor (DSP) ( 180 ) is used as an example of the controller, and the air-flow sensor is used as a capacitor of an oscillator circuit of the DSP. In this regards, the capacitive output terminals of the air-flow sensor are connected to the oscillator input terminals of the DSP. Instead of measuring the actual capacitance of the air flow sensor, the present arrangement uses a simplified way to determine the capacitance value or the variation in capacitance by measuring the instantaneous oscillation frequency of the oscillator circuit or the instantaneous variation in oscillation frequency of the oscillator circuit compared to the neutral state frequency to determine the instantaneous capacitance value or the instantaneous variation in capacitance value. For example, the oscillation frequency of an oscillator circuit increases and decreases respectively when the capacitor forming part of the oscillator decreases and increases.
[0035] To utilize these frequency characteristics, the neutral frequency of the oscillator, that is, the oscillation frequency of the oscillator circuit of the DSP with the air-flow sensor in the condition of FIG. 6A is calibrated or calculated and then stored as a reference oscillation reference. The variation in oscillation frequency in response to a suction action is plotted against flow rate so that the DSP would send an actuation signal to the heater or the heater switch when an inhaling action reaching a threshold air-flow rate has been detected. On the other hand, the DSP will not actuate the heater if the action is a blowing action to mitigate false heater triggering.
[0036] Naturally, the detection threshold frequency would depend on the orientation of the air-flow sensor. For example, if the air-flow sensor is disposed within the main housing with the upper aperture facing the LED end of the electronic smoke, an increase in oscillation frequency (due to decrease in capacitance as FIG. 6B ) of a sufficient threshold would correspond to a suction action of a threshold air-flow rate requiring heating activation, while a decrease in oscillation frequency (due to increase in capacitance as FIG. 6C ) would correspond to a blowing action requiring no heating activation regardless of the air flow rate.
[0037] On the other hand, if the air-flow sensor is disposed in an opposite orientation such that the lower aperture is opposite the LED end, an increase in oscillation frequency (due to decrease in capacitance as FIG. 6B ) of a sufficient threshold would correspond to a blowing action requiring no heater activation regardless of the air flow rate, while a decrease in oscillation frequency (due to increase in capacitance as FIG. 6C ) would correspond to a suction action requiring heating activation when a threshold deviation in frequency is detected.
[0038] The schematic equivalent circuit of FIG. 3 provides an useful reference to the characteristics above.
[0039] While the present invention has been explained with reference to the embodiments above, it will be appreciated that the embodiments are only for illustrations and should not be used as restrictive example when interpreting the scope of the invention.
[0000]
Table of Numerals
10
Electronic cigarette
100
Inhale detector
120
Air-flow sensor
121
Conductive membrane
122
Conductive back plate
123
Insulating spacer
124
Earth plate
125
Conductive ring
126
Metallic can
130
LED light source
140
Printed Circuit Board
150
Capacitance measurement unit
160
Microcontroller
170
LED driver
180
Digital signal processor (DSP)
200
Battery
300
Heating element
400
Main housing
420
First tubular portion
440
Second tubular portion
460
Third tubular portion
462
Mouth piece
500
Cover | An electronic smoke comprising an inhale detector and a smoke effect generating circuitry. The inhale detector comprises an air-flow sensor which is arranged to detect direction and rate of air flow through the smoke apparatus, and the smoke effect generating circuitry is arranged to operate the smoke effect generating circuitry to generate smoking effect when the air flow direction corresponds to inhaling through the apparatus and the air flow rate reaches at predetermined threshold. Such an electronic smoke alleviates the problem of inadvertent triggering due to environmental vibration or noise or children playing by blowing into the device. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to an automatic transmission for a motor vehicle, and more particularly to a hydraulic control system for such an automatic transmission.
In the prior art, hydraulic control systems for use in automatic transmissions include a shift valve, which supplies a hydraulic pressure to a frictional engaging means in response to a throttle pressure (a pressure produced in response to an opening of an intake throttle valve) and a governor pressure (a pressure associated with a vehicle speed). In a shift valve (so called clutch-to-clutch shift valve) which is adapted to change over the delivery of hydraulic pressure from one frictional engaging means to another upon shifting of speeds, a governor pressure, a throttle pressure and a spring force act on a valve element in opposing relationship. The valve element of such a valve should preferably be shifted to a desired position, with a movement comprising or corresponding to a snap action, immediately after the connection of a port has been changed over. For insuring such a snap action movement for the shift valve, it has been a common practice to provide an arrangement, such that when the valve element is displaced a given distance, then a governor-pressure-acting area is increased to a considerable degree or that a pressure from a hydraulic servo is introduced so as to act on the valve element. However, these prior art attempts have suffered from several disadvantages.
First, in response to displacement of the valve element, a spring force is increased or decreased, so that due to the communication-lapping arrangement of a land, such a snap action can not likewise be attained for both upshift and downshift of the valve element when merely resorting to a change in governor-pressure-acting area. The result is that the valve element tends to make a stop half way through its movement, and then pressure is dropped to a level which depends on a balance in hydraulic pressure between supply and discharge sides. This leads to a failure to attain a desired shifting characteristic, and hence a seizure or abnormal wear of frictional engaging means results.
Secondly, in case a snap action is applied according to a servo pressure, then the degree of freedom of hysteresis between shifting lines of upshift and downshift is limited, thus resulting in a failure to provide an optimum speed-shifting characteristic in terms of the drive-feel which is produced.
Thus, it is a principal aim of the present invention to provide a shift valve for use in a hydraulic control system in an automatic transmission, which provides a desired snap action upon upshift and downshift.
SUMMARY OF THE INVENTION
According to the present invention, a hydraulic control system for use in an automatic transmission is provided which includes: first frictional engaging means operable when shifting to a low speed drive; a first hydraulic servo, to which a hydraulic pressure is supplied so as to operate the first frictional engaging means; second frictional engaging means operable when shifting to a high speed drive; a second hydraulic servo, to which a hydraulic pressure is supplied so as to operate the second frictional engaging means; a throttle pressure control valve delivering a throttle pressure associated with the opening of an intake throttle valve and vehicle speed; a governor pressure control valve for delivering a governor pressure associated with vehicle speed; and a shift valve having a valve element adapted to change over the supply of hydraulic pressure from the first hydraulic servo to the second hydraulic servo upon upshift, and from the second hydraulic servo to the first hydraulic servo upon downshift, in association with the throttle pressure and the governor pressure, respectively; the valve element being movable between a first position and a second position in a manner that when the valve element is displaced towards the first position the throttle pressure acts thereon, and when the valve element is displaced towards the second position the governor pressure and a pressure being supplied to the second hydraulic servo are applied thereto only when the aforesaid pressure is supplied to the second hydraulic servo, whereby when the valve element is displaced a given distance from the second position to the first position, the pressure being supplied to the second hydraulic servo acts on the valve element, whereuoon the governor-pressure-acting area of the valve element is increased.
According to another aspect of the present invention, there is provided a hydraulic control system for use in an automatic transmission with an arrangement similar to that described above, wherein when the valve element is displaced towards the first position, the element has applied thereto a throttle pressure and a pressure being supplied to the first hydraulic servo, only when the aforesaid pressure is supplied thereto; and when the valve element is displaced towards the second position, the element has applied thereto a governor pressure, whereby when the element in the shift valve is displaced a given distance from the second position towards the first position, the pressure being supplied to the first hydraulic servo may act on the element, whereupon a governor-pressure-acting area of the valve element is decreased.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a diagrammatic view of the arrangement of a torque converter and a transmission gearing with which the present invention may be used; and
FIG. 2 is a schematic view of one embodiment of a hydraulic control system according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The hydraulic control system according to the present invention will now be described in more detail with reference to the accompanying drawings. FIG. 1 shows an outline of an arrangement of a hydrodynamic torque converter and transmission gearing. The automatic transmission includes a torque converter 1, overdrive mechanism 2, and three forward speed range drive and one rear drive change-gear mechanism 3, and is controlled by means of a hydraulic control system as shown in FIG. 2. The torque converter 1 is of a known type, which includes pump vanes 5, turbine vanes 6 and stator vanes 7. The pump vanes 5 are coupled to a crank shaft 8 of an engine, while the turbine vanes 6 are coupled to a turbine shaft 9. The turbine shaft 9 serves as an output shaft of the torque converter 1, as well as an input shaft of the overdrive mechanism 2, being coupled to a carrier 10 for a planetary gear set in the overdrive mechanism.
A planetary pinion 14 which is rotatably supported by the carrier 10 meshes with a sun gear 11 and a ring gear 15. Provided between the sun gear 11 and the carrier 10 are a multiple disc clutch 12 and a one-way clutch 13, while another multiple disc clutch 19 is provided between the sun gear 11 and a housing which houses an overdrive mechanism or an overdrive casing 16.
The ring gear 15 in the overdrive mechanism 2 is coupled to an input shaft 23 in the change-gear mechanism 3. Provided between the input shaft 23 and an intermediate shaft 29 is a multiple disc clutch 24. Still another multiple disc clutch 25 is provided between a sun gear shaft 30 and a transmission casing 18. A sun gear 32 mounted on the sun gear shaft 30 forms two-train planetary gear mechanisms in cooperation with the carrier 33, planetary pinion 34 carried by the carrier 33, a ring gear meshing with the pinion 34, another carrier 36, a planetary pinion 37 carried by the carrier 36, and a ring gear 38 meshing with the pinion 37. A ring gear 35 in another planetary gear mechanism is coupled to the intermediate shaft 29. The carrier 33 in this planetary gear mechanism is coupled to the ring gear 38 in another planetary gear mechanism, while these carrier and ring gears are coupled to an output shaft 39. In addition, a multiple disc clutch 27 and a one-way clutch 28 are provided between the carrier 36 and the transmission casing 18 in the other planetary gear mechanism.
With the automatic transmission having an overdrive mechanism thus arranged, engagement and release of respective clutches and brakes are effected in response to the load on an engine of the vehicle and to vehicle speed by means of the hydraulic control system, to be described in more detail hereinafter, thereby providing four forward speed range drives including an overdrive (O/D), and one reverse drive according to manual shifting.
The relationship among the change-gear positions, clutches and brakes is summarized in the following Table 1.
Table 1__________________________________________________________________________frictional engagingmeans clutch clutch clutch brake brake brake one-way clutch one-way clutchshift position 12 24 25 19 26 27 13 28__________________________________________________________________________parking O X X X X Oreverse drive O X O X X O lock lockneutral O X X X X X 1st O O X X X X lock lock D-range drive 2nd O O X X O X lock over-runforward speed 3rd O O O X X X lock over-runrange O.D. X O O O X X over-run over-run 1st O O X X X X lock lock 2-range drive 2nd O O X X O X lock over-run L-range drive O O X X X O lock lock__________________________________________________________________________
In Table 1, the symbol O represents the engaging condition of clutches and brakes, while the symbol X represents the release condition thereof.
FIG. 2 shows a hydraulic circuit diagram of a hydraulic control system for the automatic transmission shown in FIG. 1. Oil which has been pumped up from an oil reservoir 40 by means of an oil pump 41 is fed to a line pressure control valve 42, which in turn delivers a line pressure Pl adjusted to a given pressure level, into a hydraulic line 43. The line pressure is then supplied via hydraulic line 43a to a manual shift valve 44, and via hydraulic lines 43b and 43c to a throttle pressure control valve 45 and a detent pressure control valve 46.
The manual shift valve 44, as is well known, includes a parking position (P), reverse drive position (R), neutral position (N), D-range drive position (D), 2-range drive position (2), L or 1-range drive position (L or 1), in which a line pressure supplied into an input port 47 thereof appears at output ports 48 to 51 selectively, in response to the positions of a valve spool. Table 2 below represents the relationship of hydraulic pressure versus ports in the varying shift positions of the valve 44.
Table 2______________________________________ Hydraulic Shift Positionline P R N D 2 L______________________________________48 O O O49 O O50 O O O51 O______________________________________
The throttle pressure control valve 45 delivers a hydraulic pressure from its output port 52, which pressure is increased or decreased in response to the extent to which the accelerator pedal has been depressed, as well as to the degree of opening of the intake throttle valve. An output port 48 in the manual shift valve 44 is connected by a hydraulic line 48a to a hydraulic servo 24' in a forward clutch while a hydraulic line 48b branched therefrom is connected to an input port 54 in a governor pressure control valve 53. The governor pressure control valve 53 adjusts line pressure supplied to its input port 54 commensurate with vehicle speed, and delivers from an output port 55 a governor pressure Pgo commensurate with the vehicle speed.
The system includes a 1-2 shift valve 56, a 2-3 shift valve 57, and a 3-4 shift valve 58 (3 speed-overdrive shift valve). The 1-2 shift valve 56 includes two valve elements 60, 61 opposed in the axial direction through the medium of a compression coil spring 59.
The valve element 60 may be biased between a lower position shown at 56A and an upper position shown at 56B under the equilibrium between a downward force created by the spring 59 plus a throttle pressure Pth applied to a port 62 through the line 52a, and an upward force created by the governor pressure Pgo applied to a lower port 63 via line 55a. When the manual shift valve 44 is shifted to L - range drive position, a line pressure appearing at an output port 50 thereof is supplied via a low pressure modulator valve 66 to ports 64 and 65 of the valve element 61, so that the valve element 61 is shifted downwardly, thereby forcibly retaining valve element 60 in the lower position 56A. The valve element 60 controls the communication between an input port 80 and an output port 81.
The 2-3 shift valve 57 includes valve elements 92, 68, 69. Interposed between the valve elements 68 and 69 is a compression spring 67. The valve element 68 abuts the valve element 92. The valve element 92 has a land 93 and a land 94 of a cross sectional area smaller than that of land 93. The governor pressure Pgo is supplied via a line 55b to the ports 95, 96. The valve element 68 has a land 97 and a stem 98 at its lower end as shown in FIG. 2. The line pressure Pl is supplied via a line 48c to an input port 82 in the 2-3 speed shift valve 57, when the transmission remains in a drive range other than the first speed drive.
An output port 84 is connected via lines 48e, 49e to the hydraulic servo 25' in a multiple disc clutch 25 for the second speed drive, as well as to port 101 in the 2-3 speed shift valve 57 via a line 48g. An output port 83 is connected via line 48d to a hydraulic servo 26' for the third speed drive brake 26. A port 70 is supplied with a throttle pressure via a line 52b, while a port 72 is supplied with a line pressure Pl via a line 49b in the 2 - and L- range drives. A port 99 is supplied with a detent pressure Pd from an output port 108 in the throttle pressure control valve 45 via a line 108a, the detent pressure being adjusted in the detent pressure control valve 46. In this manner, the valve element 68 undergoes a downward force applied by the coil spring 67 and a throttle pressure from the port 70, and an upward force applied by the governor pressure from the port 95 or 96 and a pressure from the port 101, as viewed in the drawing. Thus, the input port 82 is communicated with the output port 83 (57A, lower position) or 84 (57B, upper position) depending on the predominance of one of the aforesaid two forces over the other. In the case of 2-range and L-range drives, a downward force from the port 72 is additionally applied to the valve element 68. In the case of kickdown, a downward detent pressure Pd from the port 99 is additionally applied to the valve element 68.
The 3-4 speed shift valve 58 includes a sleeve 75 and a valve element 74. A compression coil spring 83 is disposed between the valve element 74 and the sleeve 75. The valve element 74 includes, from the top downwardly as viewed in the drawing, a land 102, a land 103 having a cross sectional area larger than that of the land 102, and land 104 having a cross sectional area larger than that of the land 103, a land 105 having the same cross sectional areas as that of the land 104, and a land 106 having a cross sectional area larger than that of the land 105. The port 107 is supplied with a detent pressure Pd via a line 108b upon kickdown. A port 77 is provided midway between the lands 102, 103, and supplied with the line pressure Pl via line 49c and a shuttle valve 78 in the case of L- or 2- range drives. The port 77 is then supplied with a throttle pressure Pth via a line 52c and a shutter valve 78 in the case of a D- range drive. An input port 89 is provided midway between the lands 103 and 105, and supplied with the line pressure Pl via a line 43d. An output port 90 is provided midway between the lands 103 and 104 and connected via a line 43e to the hydraulic servo 12' for the multiple disc clutch 12 adapted to establish gear engagement in the overdrive mechanism. An output port 91 is provided midway between the lands 104 and 105, and connected via a line 43f to a hydraulic servo 19' for an overdrive multiple disc brake 19. Ports 109, 109a are supplied with a governor pressure via a line 55c.
Referring to the operation of the 2-3 speed shift valve, during the second speed drive, the governor pressure Pgo is relatively low, and hence the valve element 68 assumes the position 57A, or a lower position. In other words, the input port 82 is communicated with the output port 83, so that the hydraulic servo 26' for the second speed drive is supplied with the line pressure Pl via line 48d.
With an increase in vehicle speed, the governor pressure Pgo is increased. The governor pressure Pgo thus increased is applied from the port 96 to the land 94, thereby exerting an upward force through the medium of the valve element 92 to the valve element 68. In this manner, the valve element 68 is gradually moved upwardly. At this time, an upward force being exerted on the valve element 68 by the governor pressure Pgo is given as Pgo × S 94, wherein S94 designates the cross sectional area of the land 94.
When the valve element 68 is thus moved upwardly, the land 93 shuts off the communication between the port 96 and the land 94. Assuming that the cross sectional area of the land 93 is S93, then an upward force exerted on the valve element 68 by the governor pressure Pgo is increased to Pgo × S93 (> Pgo × S94). Almost simultaneously therewith, the input port 82 is communicated with the output port 84, so that the line pressure Pl is supplied from the output port 84 via line 48e to hydraulic servo 25' for the third speed drive, as well as via line 48g to the port 101. The line pressure Pl which has been supplied to the port 101 exerts an upward force on the valve element 68 due to a difference in cross sectional area between the land 97 and the stem 98. The upward force is represented by (Pl × S97). In this manner, the valve stem 68 is moved quickly or according to a snap action to its upper position 57B. In other words, the automatic transmission assumes the third speed drive position.
Upon third speed drive, the valve element 68 remains in the position 57B. Stated differently, the input port 82 is communicated with the output port 84, so that the line pressure Pl is supplied to the hydraulic servo 25' for the third speed drive.
With a decrease in vehicle speed, the governor pressure Pgo is lowered, so that the valve element 68 is displaced downwardly due to the throttle pressure Pth from the port 70 and the force of spring 67. When the valve element 68 is lowered a given distance, the land 94 is communicated with the port 96, so that an upward force acting on the valve element due to the governor pressure Pgo is lowered from (Pgo × S93) to (Pgo × S94). Almost simultaneously therewith, the input port 82 is shut off from communication with the output port 84, so that an upward force acting on the valve element 68 due to the line pressure Pl disappears. Accordingly, from this time on, the valve element 68 is instantaneously displaced to the lower position 57A.
Referring now to the operation of the 3-4 shift valve 58, during the third speed drive, the valve element 74 remains in the lower position 58A. At this time, an input port 89 is communicated with an output port 90, so that the hydraulic servo 12' is supplied with pressure.
With an increase in vehicle speed, the governor pressure Pgo is increased, so that the valve element 74 is gradually displaced upwardly. Assuming that a cross sectional area of a land 105 is S105, then an upward force acting on the valve element 74 due to the governor pressure Pgo is represented by (Pgo × S105). Assuming that a difference in cross sectional area between the land 103 and the land 102 is S103, then a downward force acting on the valve element 74 due to the line pressure Pl is given as (Pl × S103).
When the valve element is displaced a given distance upwardly, then the communication between the land 105 and the port 109 is shut off. Assuming that a cross sectional area of the land 106 is S106 (> S105), then an upward force acting on the valve element 74 due to the governor pressure Pgo is increased from (Pgo × S105) to (Pgo × S106). Almost simultaneously therewith, a downward force acting on the valve element 74 due to the line pressure Pl disappears. Thus, the valve element 74 is displaced to the upper position 58B instantaneously, so that the line pressure Pl is supplied to the hydraulic servo 19' for the overdrive.
During overdrive, the valve element 74 remains in the position 58B, so that the line pressure Pl is supplied to the hydraulic servo 19'.
With a decrease in vehicle speed, the governor pressure Pgo is decreased, so that the valve element 74 is displaced gradually downwardly.
When the valve element 74 is displaced a given distance downwardly, the land 105 is brought into communication with the port 109. Thus, an upward force acting on the valve element 74 due to the governor pressure Pgo is markedly lowered from (Pgo × S106) to (Pgo × S105). Almost simultaneously therewith, the input port 89 is communicated with an output port 90, so that a downward force (Pl × S104) due to the line pressure Pl is applied to the valve element 74. From this time on, the valve element 74 is instantaneously displaced to its lower position 58A.
As is apparent from the foregoing, a snap action may be achieved for valve elements in shift valve by utilizing governor pressure Pgo and line pressure Pl for a hydraulic servo on a high speed side or a hydraulic servo on a low speed side. In this case, if the snap action is caused merely by a combination of a change in cross sectional area of lands and governor pressure, then it would be difficult to achieve a compromise between both snap actions required for the upshift and downshift, because of the communication-lapping relationship of lands on a valve element. However, this may be solved by using a servo-snap action, in combination with a change in cross sectional area of lands plus the governor pressure, so that the hysteresis for the shift lines for upshift and downshift may be freely determined.
Meanwhile, according to the embodiment shown, the governor pressure Pgo and a hydraulic pressure for the hydraulic servo 25' on a high speed side, i.e., a pressure for the third speed drive and overdrive in the same direction as that of the governor pressure Pgo are utilized for the 2-3 shift valve 57, and in addition, the governor pressure Pgo and a hydraulic pressure for the hydraulic servo 12' on a low speed side i.e., a hydraulic pressure for the first to third speed drive in the opposite direction to the governor pressure Pgo are utilized for the 3-4 shift valve 58, thereby achieving a snap action. However, in contrast thereto, in place of a hydraulic pressure for the hydraulic servo 25' on a high speed side, a hydraulic pressure for the hydraulic servo 26' on a low speed side, i.e., a pressure for the second speed drive in the opposite direction of the governor pressure, may be used for the 2-3 shift valve. In addition, in place of the hydraulic pressure for the hydraulic servo 12' on a low speed side, a hydraulic pressure for the hydraulic servo 19' on a high speed side, i.e., a hydraulic pressure for the overdrive in the same direction as that of the governor pressure Pgo may be utilized for the 3-4 shift valve, with the same results.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. | A hydraulic control system for a vehicle automatic transmission includes: a first frictional engaging device operable for shifting to a low speed drive; a first hydraulic servo for the first frictional engaging device, a second frictional engaging device operable for shifting to a high speed drive; a second hydraulic servo for the second frictional engaging device; a throttle pressure control valve for delivering a throttle pressure associated with an opening of an intake throttle valve and the speed of the vehicle having the automatic transmission; and a shift valve for changing over a fluid path from the first hydraulic servo to the second hydraulic servo upon upshift of the transmission in response to the throttle pressure and a governor pressure of the system, and from the second hydraulic servo to the first hydraulic servo upon downshift of the transmission. This valve includes a valve element displaceable between a first position and a second position, and when the valve element is displaced a given distance from the first position towards the second position, a hydraulic pressure for the second hydraulic servo may be applied to the element, whereupon the governor-pressure-acting area of the valve element is increased, so that the valve element is displaced according to a snap action. Likewise, the valve element is displaced from the second position towards the first position according to a snap action, after being displaced a given distance. | 5 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to bedding, and particularly to flotation mattresses and waterbeds.
Waterbeds have become a very popular form of bedding within the last two decades. They provide an extremely soft and comfortable surface, they are relatively inexpensive, and they are readily portable. However, one continuing problem of waterbeds has been the difficulty of providing adequate support to maintain good posture in the sleeper.
A waterbed, at its simplest, is a rectangular bag (typically of vinyl), filled with water to a thickness of 3 to 9 inches. When such a bag is laid on a flat surface, it will easily support a person's weight, and thus can serve as a mattress. (Indentation is resisted not only by simple flotation, but also by the tension of the top surface of the mattress.)
A great deal of development has gone into improving this basic waterbed idea. For example, waterbeds now commonly include internal fiber, foam, or tubing to dampen sloshing. Various design improvements have also attempted to reduce the thermal coupling between the user's body and the water in the bag. For example, it is now common to provide a layer of foam atop the bag. (A host of other improvements have been made which are not particularly relevant to the claimed invention. For example, the bag is often thermostatically heated. In "hard-sided" bed structures (unlike those of the presently preferred embodiment) the complete waterbed may include a furniture structure which provides rigid sides to laterally confine the bag, and a fiat elevated platform for the bag to rest on, while maintaining the cosmetic appeal of good furniture. Numerous other improvements have been made to reduce sloshing or guard against leakage.)
Support
The support provided by a waterbed, to a sleeper in the middle of the waterbed, is provided by a combination of two components: the flotation provided by the liquid in the bag, and the sling effect provided by the lateral tensioning of the bag's top surface. This support structure provides a degree of support which is fairly soft and fairly uniform. The softness of the waterbed is a health and comfort advantage, since it avoids points of high pressure. The occurrence of pressure points will not only be uncomfortable, but will also reduce blood circulation in the affected areas. The importance of this may be seen, for example, in bedridden patients, where decubitus sores (bedsores) are a major health problem.
However, soft bedding also causes a problem, because the weight distribution of the human body is not at all uniform. The highest concentration of mass (per unit length in the height axis) will be between the shoulder blades and the hips. The mass per unit length is generally lower at the head, and is much lower in the legs. (The weight distribution is, of course, different from person to person, depending on the person's age, height, sex, obesity, and general body type. However, the problems discussed are problems for a very large fraction of users.) Thus, if the mattress is filled to a comfortable thickness for most of the body, the user's hips or buttocks will tend to sink excessively far into the mattress. (Spinal alignment, in a good sleeping posture, should be the same as that in a good standing posture. Thus, a sleeper should be supported so that his or her spine will be laterally straight, and will be curved with no more (and no less) than normal lumbar and thoracic arch and pelvic tilt. Distortions of this sleeping posture will produce immediate or gradual discomfort, and may not be optimal for the sleeper's health.) This problem is exacerbated when the mattress is used by two persons sleeping together.
This deficit in support will tend to reduce the user's comfort, to a greater or lesser degree depending on the user. However, a more important effect is that this deficit in support may permit a user to sleep in a condition of postural misalignment. This may lead to backaches, or to vague discomforts which reduce the user's overall level of health and well-being.
Some efforts have been made to increase the support under the torso. (For example, the "System 750" waterbed, from Land and Sky, includes a floating fiber structure, inside the bag, which is thicker under the user's midsection to provide additional back support. U.S. Pat. No. 5,077,848 (to McDaniel et al.) discloses an immersed tube structure, with foam inserts in the tube. The "Avanti III" model, from Pleasant Rest, is a waterbed with a foam topping, which includes extra layers of fiber (under a single sheet of foam) under the user's midsection to provide added lumbar support. The "Marvelous Middle" from Restonic includes stiffer springs in the middle of the mattress. The cover itself includes extra lines of stitching, under the sleeper's midsection, which give the impression that the middle of the cover is different from the rest of the cover, but in fact (insofar as is known to the present inventor) the cover is uniform over its length, and does NOT include any additional material under the sleeper's midsection.) Many of these have used immersed structures (inside the bag), which are prone to degradation and waterlogging over time, and cannot readily be repaired or replaced.
Apart from the art of waterbeds, other attempts have been made to design sleeping pads with some allowance for the uneven weight distribution of the human body. Many of these attempts have used convoluted foam, which is one of the basic structural materials used in designing bedding structures. (Convoluted foam (in which one surface is carved into a rippled or egg-canon shape) is effectively softer than a solid block of foam of equivalent height, because the individual protrusions in the carved portion have more room to expand laterally under pressure. Convoluted foam is described, for instance, in U.S. Pat. No. 3,026,544 to Persicke et al., which is hereby incorporated by reference. Some of the attempts to use convoluted foam pads for sleeping structures are shown in U.S. Pat. No. 4,620,337 to Williams et al.; U.S. Pat. No. 4,955,096 to Gilroy et al.; and U.S. Pat. No. 4,879,776 to Farley; all of which are hereby incorporated by reference.)
Compatibility with Bedding Materials
As noted above, waterbeds have gradually increased in acceptance, to the point where a large fraction of the U.S. residential beds are waterbeds. However, one of the difficulties still retarding waterbed acceptance is the fact that traditional sheets and blankets, and traditional methods of making up a bed, are not quite optimal for a waterbed. To some extent this difficulty is unavoidable, since the waterbed is inherently less rigid and very much heavier than the traditional box spring and mattress set. However, compatibility with the traditional "look" of a bed is an important factor in design and marketing.
One important step toward compatibility with traditional bedding is in the "soft-sided" waterbed. This bed design includes a sidewall structure of relatively stiff foam which defines the location of the water bag. (The sidewall structure may be, for example, 3 inches wide at the level of the top of the bag, tapering to 7 inches wide at the level of the base of the bag. Alternatively, it may be, for example,31/2" wide over the whole height of the bag.) An underlying layer of foam defines the relative positions of the sidewalls.
These sidewalls not only provide more rigid sides and corners for the bag when full (and thus help permit the use of traditional bedding), but also make the waterbed mattress appear very similar to a conventional mattress when empty.
Innovative Waterbed and Pad Structure
The present invention provides an improved waterbed structure, in which added lumbar support is provided by a padded cover atop the bag (which also provides extra thermal insulation and padding).
The padded cover includes a sheet of convoluted foam which covers essentially the full length of the mattress. This sheet of convoluted foam is stiffened, over the middle part of the mattress length, by a complementary piece of convoluted foam which is mated with it. The increase in thickness caused by having two pieces of convoluted foam face-to-face is relatively small. Thus, this arrangement provides extra firmness under the torso, while maintaining an essentially flat upper surface.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein:
FIG. 1 is a sectional view of the waterbed mattress structure of the presently preferred embodiment.
FIG. 2 is a bottom view (with partial cutaway) of the two-piece support structure, using two pieces of convoluted foam, of the presently preferred embodiment.
FIG. 3 is a schematic detail view of the shape and typical dimensions of a sample convoluted foam structure.
FIG. 4 is an exploded view of a sample soft-sided waterbed structure, showing the complete context in which the structure of FIG. 1 is used, in a sample embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment. However, it should be understood that this class of embodiments provides only a few examples of the many advantageous uses of the innovative teachings herein. In general, statements made in the specification of the present application do not necessarily delimit any of the various claimed inventions. Moreover, some statements may apply to some inventive features but not to others.
FIG. 3 is a schematic detail view of the shape and typical dimensions of a sample convoluted foam structure. The foam actually used, in the presently preferred embodiment, is an open-cell foam of polyurethane composition, of about 1 pound per cubic foot bulk density. The "ILD" parameter (indentation load deflection) is about 30, in the presently preferred embodiment. The convoluted shape used has a base thickness of 1/2", and an overall height of 11/2". (Thus, when two pieces of foam are mated together, their overall thickness is only 2 inches.)
FIG. 1 is a sectional view of the waterbed structure of the presently preferred embodiment. A foundation 104 supports the mattress structure at a conventional height. Bag 110 is filled with water, and also (in this sample embodiment) contains fibrous material 112 for dampening wave motion. Bag 110 is dimensioned to a standard mattress size, e.g. queen size or king size. Bag 110, in the presently preferred embodiment, is made of virgin vinyl, 18-24 mils (0.018-0.024") thick (20 mils in the presently preferred embodiment).
Bag 110 is laterally surrounded by a sidewall support structure 114, made of higher-density flexible foam. In the presently preferred embodiment, this sidewall support structure has a density of 1.5 ppcf, and an ILD of 65.
Foam padding 120A and 120B lies atop the bag 110. Foam piece 120A extends over the full width and length of the filled bag, and lies with its points down. Foam piece 120B covers the full width of the bag, but covers only the middle third (approximately) of the length of the bag. Foam piece 120B lies with its points up, so that pieces 120A and 120B are mated together over the entire area of piece 120B.
A polypropylene-damask cover 130 holds the foam padding 120 in place, and also includes additional top padding for comfort. (Of course, the cover can alternatively include other materials, such as wool batting, knit, chintz, or other fabric.) This cover is shaped as a complete zip-on enclosure, in the presently preferred embodiment; but alternatively the cover could be configured as a separable two-piece structure if desired. The foam pads 120 are glued to the cover 130, in the presently preferred embodiment, but alternatively they could be quilted to it, attached in other ways, or simply be emplaced loose to be retained by the pressure of the cover.
FIG. 2 is a bottom view (with partial cutaway) of the two-piece support structure, using two pieces of convoluted foam, of the presently preferred embodiment.
Sleepers of different heights will typically align themselves to the head end of the mattress, and the following sample dimensions take account of this. However, of course, these dimensions can be made symmetrical (so that head-foot reversal will not affect them), or otherwise altered in a variety of ways.
For example, for a king-size mattress, the dimensions of the elements described above, in the presently preferred embodiment, are: top foam padding piece 120A: 76" wide by 80" long; bottom foam padding piece 120B: 68" wide by 26" long.
Thus, the unsupported length of top piece 120A at the head end is 23 inches, and the unsupported length of top piece 120A at the foot end is 31 inches.
FIG. 4 is an exploded view of a sample soft-sided waterbed structure, showing the context in which the structure of FIG. 1 is used, in a sample embodiment.
A heavy duty metal frame 402 rests on the floor, and supports a foundation 104. The foundation 104, in the presently preferred embodiment, is simply a wood-framed structure, with a quilted cover on it, which provides a fiat top surface strong enough to support the weight of the waterbed mattress.
The cover 130 includes a top portion 130A and a bottom portion 130B, which are zipped together by a horizontal circumferential zipper 132. The cover 130 encloses the sidewall support structure 114. (Note that the sidewall support structure includes a bottom portion, extending the full width of the bed, to resist the spreading forces due to the lateral pressure of the bag.) A heater 116 (optional), a liner 118, and the bag 110, all lie within the well of support structure 114.
Foam padding 120, made of a two-layer structure as shown in FIGS. 1 and 2 (but not in FIG. 4), lies atop the bag 110, and is enclosed by cover 130.
Of course, the specific structure of FIG. 4 is not strictly necessary for the practice of the invention.
Further Modifications and Variations
It will be recognized by those skilled in the art that the innovative concepts disclosed in the present application can be applied in a wide variety of contexts. Moreover, the preferred implementation can be modified in a tremendous variety of ways. Accordingly, it should be understood that the modifications and variations suggested below and above are merely illustrative. These examples may help to show some of the scope of the inventive concepts, but these examples do not nearly exhaust the full scope of variations in the disclosed novel concepts.
For example, although the presently preferred embodiment uses soft-sided bed structure, the disclosed innovations can also, alternatively and less preferably, be adapted to a hard-sided structure.
For another example: the convoluted foam is in an egg-carton pattern, in the presently preferred embodiment. However, a ripple pattern, or another self-complementary pattern, or a pair of different but complementary patterns, could alternatively be used instead.
Of course, the dimensions and material compositions of the presently preferred embodiment have been specified merely for full compliance with the best mode requirements, and can be widely modified and varied.
One contemplated class of alternative embodiments provides an insert for hardside waterbeds, which incorporates enhanced postural support as described above.
As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a tremendous range of applications, and accordingly the scope of patented subject matter is not limited by any of the specific exemplary teachings given. | A waterbed structure, in which added lumbar support is provided by a padded cover atop the bag (which also provides extra thermal insulation and padding). The padded cover includes a sheet of convoluted foam which covers essentially the full length of the mattress. This sheet of convoluted foam is stiffened, over the middle part of the mattress length, by a complementary piece of convoluted foam which is mated with it. The increase in thickness caused by having two pieces of convoluted foam face-to-face is relatively small. Thus, this arrangement provides extra firmness under the torso, while maintaining an essentially flat upper surface. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a section 371 of International Application No. PCT/EP2011/070609, filed Nov. 22, 2011, which was published in the French language on May 31, 2012 under International Publication No. WO 2012/069436 which claims the benefit of French Patent Application No. 1059683, filed Nov. 24, 2010, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a device for stopping a container with a neck, as well as a container equipped with such a device.
With regards to containers for medication, a glass bottle is normally used to keep an active ingredient in the form of lyophilisat, in powder form or in a liquid solution. This type of bottle should be watertight to preserve the contents in a satisfactory condition, until its date of use. To hermetically seal a bottle, a device with an elastomer stopper is used which has a plastic cap placed around the stopping device to isolate the contents from the exterior.
WO-A-2007/063218 relates to a stopping device whose cap comprises a ring and a body allowing the locking means to manoeuvre the ring onto the neck of the container. It is also known as WO-A-2008/129144 for integrating a malleable component for transmission of a thrust force to a stopping device, this malleable component is destined to wear off when the thrust force has been effectively transmitted to lead a body into a position where it activates the locking means of a cap on the neck of a container. These known containers are completely satisfactory; in particular when they are used on bottles whose neck has a diameter of 20 mm.
When a stopping device has been led to a configuration where it activates its locking means, it is important that it remains on the neck of the container, without being moved other than in such a way as to clearly show that the contents of the bottle have been made accessible. This is necessary to avoid the risks of wrongful manipulation of the contents of the bottle.
It is this problem that the present invention deals with by proposing a stopping device which, when locking means are activated, is firmly held in position on the neck of a container, without any risk of untimely dismantling.
BRIEF SUMMARY OF THE INVENTION
To this effect, the invention concerns a device for stopping a container with a neck, this device comprises a stopper and a plastic cap, capable of surrounding both the stopper and the neck, the cap comprises a ring, which can surround the stopper and the neck in a raised position and has locking means on the neck, as well as a handling body for the ring provided with the first means for transmitting a thrust force to the ring and second means of activating the locking means of the ring with a thrust force and the second methods of activating the locking mechanism of the ring, this handling body surrounds the ring when it activates its locking means. This device is characterised in that the ring is provided with a continuous outer peripheral collar and the handling body is provided with at least one raised element designed to abut against the continuous outer peripheral collar when it activates the locking means.
Thanks to this invention, the cooperation between the peripheral collar, on the one hand, and the raised handling body, on the other hand, guarantees that the handling body is maintained in a position where it activates the locking means, at the point where these locking means remain effective to firmly immobilise the cap onto the neck of a container and prevent any wrongful access of the contents of the container.
According to the beneficial, but not mandatory, aspects of the invention, such a device can incorporate one or several of the following characteristics, taken in any technically admissible combination:
The raised handling body is formed using through an edge with an opening arranged through a peripheral partition of this body, this partition surrounding the ring when the handling body activates the locking means. We can anticipate that this opening abuts one part of the peripheral partition which is concave as seen from the exterior.
The locking means of the ring comprise locking tabs, which extend from an edge of this ring, towards the continuous outer peripheral collar.
The diameter of a circle passing by the external radial parts of the locking tabs has a greater external diameter of the edge from which these tabs extend.
The edge from which the locking tabs extend is continuous and each locking tab is used in an opening with a closed outline, which crosses the ring according to a radial direction in relation to the longitudinal and central axis of the ring.
The ring and the handling body are respectively provided with the first means of retaining and second methods of retaining which work together to hold the handling body in relation to the ring in a waiting position where it does not activate the locking means.
The first means of retaining the ring are arranged on the malleable bands which extend, in a parallel direction to the longitudinal and central axis of the ring, between the continuous outer peripheral collar and the annular edge of the ring from which the locking means extend.
The handling body comprises several raised sections aimed at simultaneously abutting against the continuous outer peripheral collar and are divided around a longitudinal and central axis of the handling body.
The maximum diameter of the continuous outer peripheral collar has a value greater than that of the diameter of an imaginary circle centered on the longitudinal and central axis of the handling body and crossing, on the inside, the raised parts.
The invention also relates to a container, especially a bottle for medications, equipped with a device for stopping such a container as mentioned above.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention will be better understood and other benefits of this will appear more clearly in light of the following description of a development method for a stopping device and of a container in compliance with its principle, given solely as an example, and with reference to the attached drawings in which:
FIGS. 1 to 5 as shown in the diagram, an axial cross-section and a sectional perspective of FIGS. 1 and 2 , several stages of packaging a product in containers which are in compliance with the invention,
FIG. 6 is a large scale view of the detail V I in FIG. 3 ;
FIG. 7 is an axial cross-section and a much larger scale sectional perspective, of the cap of the devices for stopping containers in FIGS. 1 to 5 ,
FIGS. 8 and 9 are fragmented perspectives, according to two different angles, of the cap in FIG. 7 ,
FIG. 10 is a larger scale view of the detail X in FIG. 4 ,
FIG. 11 is a cross section according to the line XI-XI in FIG. 10 ,
FIG. 12 is a cross section similar to FIG. 11 during an intermediary stage between the configurations of FIGS. 4 and 5 ,
FIG. 13 is larger scale view of the detail XIII of FIG. 5 and
FIG. 14 is a cross section according to the line XIV-XIII of FIG. 13 .
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 to 5 represent different stages of packaging a product P in glass bottles constituting the containers.
In FIG. 1 , bottle 1 is in the process of being filled with product P, for example, a medication. Pipette 2 is introduced into bottle 1 through its mouth 11 which is defined by a neck 12 presenting an outer collar 13 . X 1 shows the symmetrical axis of bottle 1 .
When a predetermined quantity of product P has been introduced into bottle 1 , pipette 2 is withdrawn and a stopping device, 50 , is placed on neck 12 .
The device 50 , comprises an elastomeric stopper 51 adapted to be partially introduced into the mouth 11 , while remaining on the side 131 of the collar 13 opposite the bottom 14 of the bottle 1 . Once in place in the neck 12 , the stopper 5 1 isolates the contents of the bottle 1 from the exterior.
The device 50 also comprises a cap 52 aimed at recovering and isolating the stopper 51 and the neck 12 in a closed configuration of the stopping device 50 .
As shown most particularly in FIGS. 7 to 9 , the cap 52 comprises a plastic ring 53 , which is circular on the interior section and whose internal diameter is sufficient to allow it to surround the collar 13 . The cap 52 also comprises a handling body for the ring 53 , constituted by a plastic crown 54 which is intended to constitute the external peripheral envelope of the cap 52 . The cap 52 further comprises a cover 56 also made of plastic. This cover 56 has complete rotational symmetry around a central axis X 56 .
541 shows the edge of the crown 54 which is oriented towards the bottle 1 in an installed configuration of the cap 52 on this bottle. This edge 541 can be qualified as <<inferior>> in as much as it is oriented towards the bottom in the configuration of FIGS. 2 to 5 . In this description, the spatial orientation of the different elements mentioned is considered where a device 50 is mounted on a bottle 1 which rests on a flat surface by its base 14 . One section is called <<lower>> when it is oriented towards the bottom in this configuration and <<higher>> when it is oriented towards the top.
542 shows the upper edge of the crown 54 which is opposed to the edge 541 . This edge is cut into four openings 543 which cross a partition 544 in the form of a collar which makes up the section of the crown 54 which is intended to surround the ring 53 in a mounted configuration of the cap 52 . In practice, the partition 544 comprises one cylindrical section 5441 with a circular section which extends between the edge 541 and a front face rib 5442 . Between the edge 542 and the front face rib 5442 , the partition 544 is provided with four zones 5443 which are concave seen from the exterior and which are each edged with an opening 543 .
5431 shows the edge of an opening 543 which joins zone 5443 . Each edge 5431 constitutes a raised section which extends from an area 5443 in direction of the axis X 53 .
The crown 54 also shows a central opening 545 centred on an axis X 54 , which is made up of a symmetrical axis for the crown 54 , with the exception of its parts formed by the openings 543 and by the zones 5443 . 547 shows the edge of opening 545 .
The openings 543 have the same geometry and are regularly distributed around the axis X 54 , with an angular gap of 90°.
The ring 53 is centred on an axis X 53 which is aligned with axis X 54 and X 56 in configuration with the cap 52 , this axis being merged with a central axis X 52 of the cap 52 .
The ring 53 comprises an annular section 531 which defines a central opening 532 through which the upper surface 511 of the stopper 51 can be accessed where needed.
561 shows the internal surface of the cover 56 , that is to say its surface turned towards the stopper 51 in a raised configuration of the device 50 on the bottle 1 . The cover 56 has two collars 562 and 563 which are centred on the axis X 56 and which extend parallel to this axis, each one from the surface 561 . The collar 562 has an axial length, measured parallel to axis X 56 , greater than that of the collar 563 .
During the manufacture of the cap 52 , the cover 56 is placed on the crown 54 by closing the surface 561 of the edge 542 , by introducing collars 562 and 563 in the opening 545 and in joining the cover 56 on the crown 54 , next to the edge 542 , by fusing several contacts 564 arranged for this reason on the surface 561 and equally divided around the collar 563 . During this operation, the collar 563 is brought into contact with the edge 547 .
The cover 56 is provided with a central rigid section 565 surrounded by a peripheral section 566 , also rigid, so that a malleable net 567 connects parts 565 and 566 .
When the cover 56 has been fixed onto the crown 54 , the crown 54 is covered around the ring 53 , in such a way that it delimits the maximum radial boundary of the cap 52 , in relation to its central axis X 52 .
In practice, the geometry of ring 53 , crown 54 and cover 56 is chosen in such a way that the maximum exterior diameter D 54 of the crown 54 has a value less than 16.5 mm, preferably between 15.8 and 16.2 mm, preferably again being equal to 16 mm. In these conditions, when one uses a bottle 1 whose body 16 has a diameter equal to 16 mm, what is normal for certain medications, the cap 52 mounted onto bottle 1 does not exceed or slightly exceeds the body of bottle 1 , according to a radial direction in relation to the axis X 1 . This allows the bottles 1 , pre-equipped with stopping devices 50 to be juxtaposed on a shelf of a lyophilisator, with a high density, from a relatively small diameter of the bodies of these bottles, without there being any risk of the bottles being unbalanced by the stopping divides that they support.
The ring 53 comprises five bands 533 which extend from the section 531 to the lower edge of the ring 53 which is formed by a continuous edge 534 around the axis X 53 .
Section 531 comprises a continuous collar 5311 , which extends peripherally and externally in relation to the rest of section 531 and which defines a second edge, or superior edge of the ring 53 . The collar 5311 is shown between an upper surface 5312 oriented to the opposite of edge 534 and an inferior surface 5313 oriented towards the edge 534 , each of these surfaces being perpendicular to the axis X 53 . The collar 5311 is edged, radially on the exterior, by a tapered surface 5314 which converges opposite the edge 534 .
Each band 533 has an external rib 535 which stands out radially towards the exterior in relation to axis X 53 in relation to this tab. Between each pair of two adjacent bands 533 is a window 536 , or an open area at a fixed edge, connecting the interior volume of the ring 53 to the exterior.
A locking tab 537 extends from the edge 534 in each window 536 . Taking into consideration the intrinsic suppleness of the material constituting the ring 53 , each tab 537 can pivot, around its base, in relation to the edge 534 . In other words, each tab 537 is in the form of a rib of a ribbed surface, centred on the axis X 53 and converging in the direction of the edge 5371 . Opposite the edge 5371 , centred on the axis X 53 and converging in the direction of the edge 534 . Thus, the surface 5372 constitutes the outer peripheral upper surface of a tab 537 , so that its surface 5373 constitutes an outer, inferior peripheral surface. The respective diameters of the surfaces 5372 and 5373 of a tab are chosen so that a semi-circular spout 5374 is formed at the junction between these surfaces. The spouts 5374 constitute the external radial parts of the tabs 537 .
D 534 shows the exterior diameter of the edge 534 . D 537 is the diameter of an imaginary circle C 537 centred on the axis X 53 and passing through the spouts 5374 . In an unconstrained position of the locking tabs 537 , the value of the diameter D 537 is greater than that of the diameter D 534 , by at least 1.5 mm. Even when the crown 54 surrounds the locking tabs 537 , as seen above, the diameter D 537 has a greater value than diameter D 534 , the difference between these values thus being reduced.
On the interior of the junction between a band 533 and part 531 , the ring 53 is provided with internal ribs 538 for superficially penetrating the stopper 51 to immobilise this stopper in the ring 53 and in the cap 52 .
546 shows the internal radial surface of the partition 544 . This surface is provided with a peripheral mouth 5461 which extends around the perimeter of the surface 546 and which is intended to receive the external ribs 535 of the ring 53 in a holding configuration represented in FIGS. 3 and 6 . In this configuration, the crown 54 is mounted on the ring 53 , without interacting with the locking tabs 537 .
The configuration of FIG. 7 can be achieved by sliding the crown 54 around the ring 53 thanks to the preassembly force which is axial, that is to say, parallel to the axes X 52 , X 53 , X 54 and X 56 which are staggered. The effect of this is to lead the partition 544 around the bands 533 and this movement is continued until the external ribs 535 enter the peripheral mouth 5461 and are locked there. The sliding of the crown 54 in relation to the ring 53 takes place thanks to the elasticity of the bands 533 which can change their shape elastically when their respective ribs slide along the surface 546 of the crown 54 before joining at the peripheral mouth 5461 . In other words, the geometry of the ring 53 gives the bands 533 sufficient suppleness so that the crown 54 can be easily set up around the ring 53 . In practice, the bands 533 each extend, in relation to axis X 53 onto an angular section of an angle at the top which is less than 30°, preferably at 25°, which gives them good elasticity.
When the cap 52 has been thus pre-assembled, it is possible to place the stopper 51 here by introducing it to the interior of the ring 53 , until the internal ribs 538 superficially penetrate the stopper 51 , which will ensure that the position of the stopper in the ring is maintained. As a variant, the stopper 51 can be placed on the neck 12 of the bottle 1 , as represented in FIG. 2 , before the cap 52 is placed on the stopper thanks to an axial stress E 1 . In all cases, the configuration of FIG. 3 is reached, where the stopper 51 does not completely fill the mouth 11 as this stopper is provided with a lateral cut 512 which communicates with a slot 200 at one part of the upper face 131 of the collar 13 .
The bottle 1 equipped with the device 50 can therefore be introduced into a lyophiliser 300 , in one lot of bottles 1 . In FIGS. 3 to 5 , three bottles represent one lot which can comprise several hundred, or even several million, bottles used in the lyophiliser 300 . Moreover, the bottles can be used in this lyophiliser on several stacked shelves. In this lyophiliser, the water molecules present in each bottle 1 are moved towards the exterior, as represented by the arrows F 1 in FIGS. 3 and 6 , through the slots which remain between cap 52 and the collar 13 .
Inside the lyophiliser, we can then, as represented in FIG. 4 , push E 2 on the devices 50 parallel to the longitudinal axis X 1 of the bottles 1 and the necks 12 , an axis with which is also joined the axes X 52 of the different caps 52 . This axial stress E 2 is exerted by a mobile tray 301 inside the lyophiliser and controlled by a jack 302 . The tray 301 at the same time sensitively exerts the same unitary stress R 2 on the cap 52 of each bottle 1 of a row of bottles used at the same level, on the same tray 303 in the lyophiliser. The sum of the efforts E 2 is equal to the effort E 2 .
In the configuration in FIGS. 4 and 10 , the crown 54 is in a second holding configuration where the external ribs 535 remain inserted in the peripheral mouth 5461 . In this configuration, the crown does not interact with the locking tabs 537 .
Applying stress E′ 2 has the effect of making the crown 54 of each cap 52 move in the direction of the bottom 14 of each of the bottles 1 , as represented by the passage from the configuration in FIGS. 3 and 6 to that of FIGS. 4 and 10 . The E′ 2 stress is transmitted from the crown 54 to the ring 53 through the intermediary of the peripheral mouth 5461 and the external ribs 535 which cooperate. Thus, external ribs 535 and the peripheral mouth 5461 constitute the stress transmission means E′ 2 from the crown 54 to the ring 53 . The stress E′ 2 exerted on each device 50 has the effect of leading the tabs 537 of its ring 53 along the axis X 1 , between the collar 13 and the body 16 of the bottle around the part of the neck 12 which is not provided with a collar 13 .
The annular section 531 thus makes contact with the upper surface 511 of the stopper 51 which halts the progression of the ring 53 in the direction of the base 14 . The continued application of the stress E 2 on the crown 54 of each device 50 has the effect of driving the external rib 535 of each band 533 to the exterior of the mouth 5461 by elastic deformation of the bands 533 , which allows the crown 54 to successively attain the position of FIG. 12 , then that of FIGS. 13 and 14 . Firstly, this allows the edge 541 of the crown 54 to make contact with the surfaces 5372 of the different locking tabs 537 , as represented in FIG. 12 . The continuation of this movement has the effect of making the surfaces 5372 slide against the edge 541 , which flaps the tabs 537 radially towards the axis X 1 , by moving their free side 5371 against the inferior peripheral surface 132 of the collar 13 , as represented in FIG. 14 . Thus, the edge 541 allows the locking tabs 537 to be put into an active configuration where they immobilise the cap 52 on the neck 12 .
This movement also has the effect of causing the edges 5431 of the notches or openings 543 to abut against the surface 5313 of the collar 5311 which is oriented towards the edge 534 . D 531 shows the maximum diameter of the continuous outer peripheral collar 5311 . This diameter is that of the edge of the junction between the surfaces 5313 and 5314 . C 543 shows an imaginary circle centred on an axis X 54 and close, on the interior, to the edges 5431 of the notches or openings 543 . When the zones 5443 of the partition 544 are not subject to any action by the collar 5311 , the value of the diameter D 543 is less than the value of the diameter D 531 . The zones 5443 are elastically deformed by sliding against the surface 5314 , while passing from the configuration of FIG. 12 to the configuration of FIGS. 13 and 14 . Finally, by elasticity, the parts of the partition 544 which make up zones 5443 have the tendency to fall back towards the axis X 52 , in such a way that the edges 5431 join below the continuous outer peripheral collar 5311 .
If a withdrawal stress E 3 of the crown 54 is exerted on this, as represented in FIG. 14 , this effort is transmitted in the form of abutting E 4 the sides 431 against the collar 5311 which opposes this and blocks the crown 54 in its position where it maintains the tabs 537 in configuration of entering the collar 13 .
The result of this is a particularly effective locking of the crown 54 around the ring 53 , in the configuration of FIGS. 13 and 14 . Indeed, once the stopping device 50 is mounted on the neck 12 of a bottle 1 , it is not possible to remove the crown 54 because the edges 5431 of the openings 543 are supporting the collar 5311 which is rigid and solid because of its continuous character around the axis X 53 . The only way to access the stopper 51 , and through this, the contents of the bottle 1 , is to take the cover 56 off by breaking the contacts 564 .
In the configuration of FIGS. 13 and 14 , the crown 54 is in its locking configuration in which it ensures, by the reinforcement that it exerts on the tabs 537 , that these tabs are held in a configuration which is connected to the surface 132 of the collar 13 . The crown 54 therefore constitutes a handling body of the ring 53 , this handling body activates the locking means constituted by the tabs 537 . The ring 53 , crown 54 and cover 56 are each compact and can be moulded into polyoxymethylene (POM) or into an equivalent material.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. | The invention relates to a device for stopping a container ( 1 ) having a neck ( 12 ). The device includes a stopper ( 51 ) and a plastic cap ( 52 ) configured to surround both the stopper ( 51 ) and the neck ( 12 ). The cap ( 52 ) includes a ring ( 53 ) that can surround the stopper and the neck when mounted and is provided with a locking tab ( 537 ) for locking onto the neck, and a body ( 54 ) for handling the ring, provided with an external rib ( 535 ) for transmitting a thrust force to the ring and an edge ( 541 ) for activating the tab for locking the ring. The ring ( 53 ) is provided with a continuous outer peripheral collar ( 5311 ), and the handling body ( 54 ) is provided with at least one raised element ( 5431 ) designed to abut (E 4 ) against the continuous outer peripheral collar ( 5311 ) when the edge ( 541 ) activates the locking tab ( 537 ). | 1 |
FIELD OF THE INVENTION
The present invention relates to closed-loop emission control apparatus for internal combustion engines in which compensation signals are generated in response to a sensed sudden change of engine load to compensate for leaner mixture during acceleration and richer mixture during deceleration.
BACKGROUND OF THE INVENTION
In a closed-loop emission control system for internal combustion engines, the concentration of exhaust composition is detected to provide an error correction signal with which the mixture ratio of air to fuel is controlled at a predetermined value. However, due to the transport delay time of the engine involved in induction of air and fuel, combustion of the mixture and emission of the exhaust gases in each cylinder cycle, the closed-loop control is not capable of responding to a sudden change of load such as acceleration or deceleration and therefore a loss of power will be encountered when the engine is suddenly accelerated. In a prior art system in which a throttle position sensor is provided, a differentiator circuit is connected to the output of throttle position sensor. The differentiator output is then impressed upon the error correction signal to compensate for the transient engine operating conditions when throttle position has suddenly changed.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved closed-loop emission control system for an internal combustion engine capable of responding to a sudden change of engine load.
The improved emission control system according to the present invention is characterized by the fact that a step function voltage of positive or negative polarity depending on a sensed acceleration or deceleration is impressed upon the error correction signal to generate a compensation signal. Preferably, the step voltage is impressed upon a mean value of the error correction signal, or alternatively, impressed upon the error correction signal of amplitude immediately prior to the detection of the change of engine load. The error correction signal is therefore instantaneously varied in a given direction and remains there for appropriate duration so that additional amount of fuel is supplied to the engine to compensate for loss of power during acceleration, or instantaneously varied in the opposite direction and remains there for appropriate duration so that mixture is leaned to compensate for the richer mixture during deceleration.
Another object of the present invention is to provide emission control apparatus which assures good drivability when sudden change of load is encountered.
A further object of the invention is to minimize the amount of noxious emissions during the period of acceleration or deceleration.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details will be explained below with the help of the examples illustrated in the accompanying drawings in which:
FIG. 1 is a schematic illustration of emission control apparatus embodying the invention;
FIG. 2 is a circuit diagram of a control unit used in the embodiment of FIG. 1; and
FIG. 3 is a modification of the circuit of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, an air-fuel mixing and proportioning device 10 supplies mixture of air and fuel to an internal combustion engine 11. In the exhaust passage of the engine is provided an exhaust composition sensor 12 of the type which senses the concentration of residual composition such as oxygen in the exhaust emissions and provides an output having a characteristic change in amplitude in the neighborhood of the stoichiometric air-fuel ratio of the combusted mixture. The output from the exhaust gas sensor 12 is applied to a comparator 13 for comparison with a reference voltage Vref to provide a signal representative of the difference between the two voltages. A control unit 14 accepts the signal from the comparator 13 to generate an error correction signal which is in turn coupled to the air-fuel mixing and proportioning device 10. The mixing device 10 may be a carburetor with a control valve operated by the signal from the control unit 14 either in analog or digital form, or a fuel injector controlled in analog or digital form.
FIG. 2 illustrates in detail the control unit 14. The output from the comparator 13 is fed into the inverting input of an operational amplifier OP1 through an input resistor R1. The inverting input is connected through a series-connection of resistor R2 and capacitor C1 to the output terminal, the noninverting input being connected to ground. With this circuit configuration, the output signal from the operational amplifier OP1 is a sum of proportional amplification by the factor of R2/R1 and integration by the time constant R1C1, respectively, of the comparator output. Therefore, the circuit 20 formed by the operational amplifier OP1, resistors R1, R2 and capacitor C1 acts as a proportional-integral controller which generates a basic error correction signal. This signal is applied to an averaging circuit 21 formed by an operational amplifier OP2 and an RC filter 21a formed by resistor R3 and capacitor C2. The output from the PI controller 20 is connected to one end of the resistor R3 the other end of which is connected to the noninverting input of the operational amplifier OP2 and through the capacitor C2 to ground. The inverting input of the operational amplifier OP2 is connected to the output thereof so that the amplifier OP2 acts as a buffer amplifier stage.
The output from the PI controller 20 is also connected through a voltage divider 22 formed by a series-connected resistors R4 and R5 to an electronic switching gate SW1 and thence to air-fuel mixing device 10 through an output lead 30, the switch SW1 being closed by a control signal from a NOR gate 23.
The output of averaging circuit 21 is connected to a junction between a second voltage divider 24 formed by a series-connected resistors R6 and R7 and a third voltage divider 25 formed by a series-connected resistors R8 and R9. The voltage divider 24 is connected at the other end to a positive voltage supply +V 1 and voltage divider 25 is connected at the other end to a negative voltage supply -V 2 .
The voltage at the junction B between resistors R6 and R7 is a sum of the output voltage from operational amplifier OP2 and the positive voltage V 1 divided by the ratio of resistances R6 to R7. This voltage serves as a first correcting signal substituted for the basic control signal provide a rich mixture during acceleration periods and is coupled through an electronic switching gate SW2 to the output lead 30.
The voltage at the junction C between resistors R8 and R9 is a sum of the output voltage from operational amplifier OP2 and the negative voltage V 2 divided by the ratio of resistances R8 and R9. This voltage serves as a second correcting signal substitute for the basic control signal to provide a lean mixture during deceleration periods and is applied through a third electronic switching gate SW3 to the output lead 30.
In order to sense acceleration and deceleration conditions of the vehicle, a potentiometer or throttle position transducer 26 is connected between a positive voltage supply +Vcc and a negative voltage supply -Vcc. A differentiator 27 formed by resistor R10 and capacitor C3 is connected to the tap point of the potentiometer 26 to provide a differentiated voltage across the resistor R10. The potentiometer wiper is operatively connected by a linkage as indicated by dot-dash lines to the throttle valve 28 for unitary movement therewith. The voltage developed across the resistor R10 represents the rate of movement of the throttle valve 28, and is applied to the noninverting input of a first operational amplifier comparator OP3 for comparison with a reference voltage V 3 and also to the inverting input of a second comparator OP4 for comparison with a reference voltage V 4 . The comparator OP3 will be switched on to the output-high state when the potential at the non-inverting input is above the reference voltage V 3 to activate a first monostable multivibrator 29a producing a pulse with a predetermined duration. The comparator OP4 will be triggered into the output-high state when the potential at the inverting input is below the reference potential V 4 to activate a second monostable multivibrator 29b. The outputs from the monostable multivibrators 29a and 29b are connected on the one hand to respective ones of the input terminals of the NOR gate 23 and on the other hand to the control terminals of electronic switching gates SW2 and SW3, respectively. The output from monostable 29a is thus an indication of acceleration condition and the output from monostable 29b is an indication of deceleration condition. When both conditions do not exist, the NOR gate 23 will be activated to place a logic "1" to the control terminal of switching gate SW1 to connect the potential at the junction A to the output lead 30 and thence to the air-fuel mixing and proportioning device 10.
The output from the PI controller 20 is smoothed out by the RC filter 21a so that the output delivered from the operational amplifier OP2 can be regarded as a mean value of the amplitude of the signal from the PI controller during the period of acceleration or deceleration, or the period of monostable multivibrators 29a and 29b. Therefore, the potential at the junction B is a value proportional to the average value of the basic control signal at the moment of acceleration from the PI controller 20 plus a positive step function voltage from the voltage supply +V 1 , and the potential at the junction C is a value proportional to the average value of the basic control signal at the moment of deceleration plus a negative step function voltage from the voltage supply -V 2 .
Upon detection of acceleration, the monostable multivibrator 29a is activated to provide a control signal to the switch SW2 to apply the potential at junction B to the air-fuel mixing device 10 through lead 30. As a result, an additional amount of fuel is supplied to the internal combustion engine 11 without loss of time and fuel deficiency during the acceleration period is compensated.
Upon detection of deceleration, the monostable multivibrator 29b is activated to provide a control signal to the switch SW3 to apply the potential at junction C to the air-fuel mixing device 10 to instantly decrease the supply of fuel to the engine so that richness during the deceleration period is compensated.
The averaging circuit 21 of FIG. 2 may be replaced with a circuit 40 as shown in FIG. 3 in which the output from the PI controller 20 is connected through an electronic switching gate SW4 to the noninverting input of an operational amplifier OP5 and also to one terminal of a capacitor C4, the opposite terminal of which is connected to ground. The logic "1" output from the NOR gate 23 is connected to the control terminal of electronic switching gate SW4 so that the switching gate SW4 is normally closed to charge the capacitor C4.
When acceleration or deceleration is detected, NOR gate 23 will be switched on to a logic "0" state which causes the switching gate SW4 to open. The voltage developed across the capacitor C4 represents the value of the controller output at the instant immediately prior to the detection of acceleration or deceleration. The operational amplifier OP5 has its inverting input connected to its output terminal to act as a buffer amplifier in a manner identical to the operational amplifier OP2 of the previous embodiment to generate compensation voltages at the junction B or C. | Emission control apparatus for an internal combustion engine includes a sensor for detecting the concentration of an exhaust composition to generate an error correction signal for controlling the air-fuel mixture ratio at a predetermined value to minimize noxious exhaust emissions and a transient compensation circuit to provide a step function voltage to compensate for transient engine operating condition in response to a sensed change of engine load. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional application of U.S. patent application Ser. No. 12/559,453 filed on Sep. 14, 2009, which claims priority to and the benefit of Korean Patent Application No. 10-2009-0018995 filed in the Korean Intellectual Property Office on Mar. 5, 2009, the entire contents of which are incorporated herein by reference.
BACKGROUND
(a) Technical Field
The present invention relates to a liquid crystal display device, and more particularly, to a vertical alignment liquid crystal display.
(b) Description of the Related Art
Liquid crystal displays (LCDs) are now widely used as one of the prominent flat panel displays. A liquid crystal display device has two display panels on which field generating electrodes, such as pixel electrodes and common electrodes, are formed, and a liquid crystal layer is interposed between the panels. In a liquid crystal display device, voltages are applied to the electrodes and an electric field generated across the liquid crystal layer determines the alignment of liquid crystal molecules. By controlling the incident light polarization according to the display data signals a video image is displayed on the LCD panel.
Among the liquid crystal displays, a vertical alignment (VA) mode liquid crystal display has an advantage of a high contrast ratio and a wide reference viewing angle, which is defined as the viewing angle at a contrast ratio of 1:10, also known as the intergray luminance inversion limitation angle. In VA mode liquid crystal display, the axes of the liquid crystal molecules orient perpendicular to the upper and lower display panels when an electric field is not applied thereto.
In the vertical alignment (VA) mode liquid crystal display, cutouts or protrusions may be formed on the field-generating electrodes to widen the viewing angle. The cutouts or protrusions modify the orientation of the liquid crystal molecules nearby, thus widening the reference viewing angle.
However, the lateral visibility of the vertical alignment (VA) mode liquid crystal display is lower than the front visibility. For example, with a patterned vertically aligned (PVA) liquid crystal display with cutouts, the image becomes brighter toward the lateral side, and in a worst case, the luminance difference between the high grays is eradicated so that the picture image may appear to have collapsed.
Information disclosed in the Background section is meant for understanding the invention background and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.
SUMMARY
An aspect of the present invention is to provide a vertical alignment liquid crystal display having the advantage of enhanced lateral visibility.
In one or more embodiments of the present invention, a pixel is contains a high gray sub-pixel and a low gray sub-pixel, based on variable capacitors.
An exemplary embodiment of the present invention provides a display device including a plurality of gate lines, a plurality of data lines, and a pixel connected to one of the plurality of gate lines and one of the pluralities of data lines. The pixel includes first and second sub-pixels. The first sub-pixel includes a first thin film transistor having control and input terminals connected to the gate and data lines, respectively, and a first liquid crystal capacitor and a first variable capacitor respectively connected to the output terminal of the first thin film transistor. The second sub-pixel includes a second thin film transistor having control and input terminals connected to the gate and data lines respectively, and a second liquid crystal capacitor and a second variable capacitor respectively connected to the output terminal of the second thin film transistor.
The first and second variable capacitors may have a first capacitance when the voltage applied to the gate electrode reaches or exceeds a predetermined voltage, and they have a second capacitance when the voltage applied to the gate electrode is less than the predetermined voltage.
When one of the first and second variable capacitors has the first capacitance, the other variable capacitor may have the second capacitance.
The first and second variable capacitors may each be formed with a thin film transistor including a gate electrode, a semiconductor layer, a source electrode, and a drain electrode, and the source and drain electrodes may be electrically connected to each other.
The source and drain electrodes of the first variable capacitor may be connected to the output terminal of the first thin film transistor, and the gate electrode of the second variable capacitor may be connected to the output terminal of the second thin film transistor.
The first capacitance may be stored at a region where the semiconductor layer, the source and drain electrodes, and the gate electrode overlap. The second capacitance may be stored at a region where the source and drain electrodes overlap with the gate electrode. An ohmic contact layer may be formed between the source and drain electrodes and the semiconductor layer.
The first capacitance may be stored at a region where the semiconductor layer, the ohmic contact layer, and the source and drain electrodes overlap with the gate electrode. The second capacitance may be stored at a region where the ohmic contact layer and the source and drain electrodes overlap with the gate electrode.
The first and second variable capacitors may each include a gate electrode, a semiconductor layer, and an upper electrode, where the upper electrode may partially overlap with the gate electrode and the semiconductor layer. The upper electrode of the first variable capacitor may be connected to the output terminal of the first thin film transistor, and the gate electrode of the second variable capacitor may be connected to the output terminal of the second thin film transistor.
The first capacitance may be stored at a region where the semiconductor layer and the upper electrode overlap with the gate electrode. The second capacitance may be stored at a region where the upper electrode overlap with the gate electrode. An ohmic contact layer may be formed between the upper electrode and the semiconductor layer.
The first capacitance may be stored at a region where the semiconductor layer, the ohmic contact layer, and the upper electrode overlap with the gate electrode. The second capacitance may be stored at a region where the ohmic contact layer and the upper electrode overlap with the gate electrode.
Another exemplary embodiment of the present invention provides a display device including a plurality of gate lines, a plurality of data lines, and a pixel connected to one of the plurality of gate lines and one of the pluralities of data lines. The pixel includes a thin film transistor with control and input terminals connected to the gate and data lines, respectively, and a liquid crystal capacitor and a variable capacitor respectively connected to the output terminal of the thin film transistor, wherein the variable capacitor is formed with a thin film transistor.
The variable capacitor may have a thin film transistor structure with a gate electrode, a semiconductor layer, a source electrode, and a drain electrode, and the source and drain electrodes may be electrically connected to each other.
The variable capacitor may be formed with a structure where either a source electrode or a drain electrode is removed from a thin film transistor structure of a gate electrode, a semiconductor layer, and source and drain electrodes.
In this way, variable capacitors are formed within each pixel such that the pixel is bisected into a high gray sub-pixel and a low gray sub-pixel. The bisected sub-pixels express different grays so that the lateral visibility is enhanced. It is not needed in bisecting a pixel into two sub-pixels to form separate wires for applying different signals thereto, and the amount of data to be processed at the driver for driving the display device is reduced. Furthermore, a pixel is bisected into two sub-pixels with variable capacitors in a simplified manner, and it is not required to form additional wires and elements, so the aperture ratio is enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an equivalent circuit diagram of a pixel in a liquid crystal display device according to an exemplary embodiment of the present invention.
FIG. 2 is a voltage-capacitance graph of the variable capacitors according to an exemplary embodiment of the present invention.
FIG. 3 is a graph illustrating voltage variations at the thin film transistor output terminals a of the two sub-pixels according to an exemplary embodiment of the present invention.
FIG. 4 is an equivalent circuit diagram of a pixel of a liquid crystal display according to an exemplary embodiment of the present invention.
FIG. 5 and FIG. 6 are cross-sectional views of the variable capacitors shown in FIG. 4 according to an exemplary embodiment of the present invention.
FIG. 7 is a voltage-capacitance graph of the variable capacitors shown in FIG. 6 according to an exemplary embodiment of the present invention.
FIG. 8 and FIG. 9 are graphs illustrating the voltage-current characteristics under the stress from the variable capacitors shown in FIG. 4 according to an exemplary embodiment of the present invention.
FIG. 10 and FIG. 11 are cross-sectional views of variable capacitors according to another exemplary embodiment of the present invention.
DETAILED DESCRIPTION
The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.
A display device according to an exemplary embodiment of the present invention will be first described with reference to FIG. 1 .
FIG. 1 is an equivalent circuit diagram of a pixel of a liquid crystal display according to an exemplary embodiment of the present invention.
As shown in FIG. 1 , with a liquid crystal display according to an exemplary embodiment of the present invention, a pixel 900 includes two sub-pixels 901 and 902 . The sub-pixels 901 and 902 include thin film transistors Qs_h and Qs_l, liquid crystal capacitors Clc_h and Clc_l, and variable capacitors Cst_h and Cst_l, respectively. The sub-pixels 901 and 902 receive the same voltage through a data line Dj, but the voltages applied to the liquid crystal capacitors Clc_h and Clc_l are different depending upon the operation of the variable capacitors Cst_h and Cst_l. As a result, images display different levels of gray by controlling the liquid crystal capacitors Clc_h and Clc_l. The sub-pixel 902 expressing a lower gray will be referred to hereinafter as the low gray sub-pixel, and the sub-pixel 901 expressing a higher gray will be referred to as the high gray sub-pixel.
The relationship of the sub-pixels will be first described in detail.
The high gray sub-pixel 901 includes a thin film transistor Qs_h with a control terminal connected to a gate line Gi and an input terminal connected to the data line Dj. A liquid crystal capacitor Clc_h and a variable capacitor Cst_h are respectively connected to the output terminal of the thin film transistor Qs_h.
The liquid crystal capacitor Clc_h includes a pixel electrode (not shown), a common electrode (not shown), and a liquid crystal layer (not shown)interposed between the pixel and common electrodes. The pixel electrode, which is connected to the output terminal of the thin film transistor Qs_h, receives a data voltage, and the common electrode receives a common voltage Vcom. When an electric field is generated from the voltage difference between the pixel and common electrodes, the liquid crystal molecules reorient to the electric field so that the light polarization is modified quantitatively and an image is displayed.
The variable capacitor Cst_h has its first and second electrodes (not shown) at both ends, and an insulating layer (not shown) disposed between those electrodes. The first electrode, which is connected to the output terminal of the thin film transistor Qs_h, receives a data voltage, and the second electrode receives a reference voltage Vref. The reference voltage Vref may be identical with the common voltage Vcom. The variable capacitor Cst_h according to an exemplary embodiment of the present invention may have polarities, and it may be structured with the high gray sub-pixel 901 that the first electrode connected to the output terminal of the thin film transistor Qs_h has a positive (+) polarity. The variable capacitor Cst_h has the characteristic that the cumulated capacitance rises fast at a predetermined voltage, and reaches its plateau afterwards. This will be described more specifically with reference to FIG. 2 .
Meanwhile, a parasitic capacitance Cph is formed between the gate line Gi and the output terminal of the thin film transistor Qs_h.
With the high gray sub-pixel 901 , the voltage varies at the output terminal (region A) of the thin film transistor Qs_h due to the characteristic of the variable capacitor Cst_h so that the characteristic of the liquid crystal capacitor Clc_h is altered. At this time, the parasitic capacitance Cph may also be altered, and this will be described later with reference to FIG. 3 .
Similarly, the low gray sub-pixel 902 includes a thin film transistor Qs_l with a control terminal connected to the gate line Gi and an input terminal connected to the data line Dj. A liquid crystal capacitor Clc_l and a variable capacitor Cst_l are connected to an output terminal of the thin film transistor Qs_l.
The liquid crystal capacitor Clc_l includes a pixel electrode (not shown), a common electrode (not shown), and a liquid crystal layer (not shown) interposed between those electrodes. The pixel electrode, which is connected to the output terminal of the thin film transistor Qs_l, receives a data voltage, and the common electrode receives a common voltage Vcom. When an electric field is generated from the voltage difference between the pixel and common electrodes, the liquid crystal molecules reorient to the electric field so that the light polarization of light is modified quantitatively and an image is displayed.
The variable capacitor Cst_l has its first and second electrodes (not shown) at both ends, and an insulating layer (not shown) is disposed between those electrodes. The first electrode, which is connected to the output terminal of the thin film transistor Qs_l, receives a data voltage, and the second electrode receives a reference voltage Vref. The reference voltage Vref may be identical with the common voltage Vcom. The variable capacitor Cst_l according to an exemplary embodiment of the present invention may have polarities, and it may be structured with the low gray sub-pixel 902 that the first electrode connected to the output terminal of the thin film transistor Qs_l has a negative (−) polarity. The variable capacitor Cst_l has the characteristic that cumulated capacitance rises fast at a predetermined voltage, and reaches its plateau afterwards. This will be described more specifically with reference to FIG. 2 .
Meanwhile, a parasitic capacitance Cpl is formed between the gate line Gi and the output terminal of the thin film transistor Qs_l.
In the low gray sub-pixel 902 , the voltage varies at the output terminal (region B) of the thin film transistor Qs_l from the variable capacitor Cst_l so that the capacitance of the liquid crystal capacitor Clc_l varies. At this time, the parasitic capacitance Cpl may also be altered, and this will be described later with reference to FIG. 3 .
The operational characteristics of the variable capacitors Cst_h and Cst_l will now be described in detail.
FIG. 2 is a voltage-capacitance graph of the variable capacitors according to an exemplary embodiment of the present invention. In the graph of FIG. 2 , the horizontal axis represents voltage applied across each of the variable capacitors Cst_h and Cst_l, and the vertical axis represents the capacitances stored in the variable capacitors Cst_h and Cst_l.
The variable capacitors Cst_h and Cst_l according to an exemplary embodiment of the present invention have the characteristic that the cumulated capacitance quickly risesat a predetermined voltage (indicated in the drawing as 0), and reaches its plateau afterwards. As a result, a difference in capacitance ΔC exists between the minimum capacitance Cmin obtained under the application of the predetermined voltage or less and the maximum capacitance Cmax obtained under the application of more than the predetermined voltage. As the variable capacitors Cst_h and Cst_l have polarities, they exhibit the maximum capacitance Cmax when a voltage equal to or higher than the predetermined voltage is applied to the positive (+) terminal. By contrast, when the voltage is applied to the negative (−) terminal, the variable capacitors Cst_h and Cst_l exhibit the minimum capacitance Cmin because the applied voltage does not influence the capacitance, and the voltage variation over both ends s minimum.
The two sub-pixels 901 and 902 are bisected into the high gray sub-pixel 901 and the low gray sub-pixel 902 due to the difference in capacitance ΔC, and this will now be described in detail with reference to FIG. 3 .
FIG. 3 is a graph illustrating the voltage variation at the output terminal of the thin film transistor in both sub-pixels according to an exemplary embodiment of the present invention.
In the graph of FIG. 3 , Vg represents the gate voltage applied to the gate line Gi, VA represents the voltage at the terminal at region A (the A terminal) of the high gray sub-pixel 901 shown in FIG. 1 , and VB represents the voltage at the terminal at region B (the B terminal) of the low gray sub-pixel 902 . Furthermore, VkA represents the kickback voltage at the A terminal of the high gray sub-pixel 901 , and VkB represents the kickback voltage at the B terminal of the low gray sub-pixel 902 . The graph of FIG. 3 illustrates the results measured after applying the reference voltage Vref which has the same magnitude as the common voltage Vcom.
When the gate voltage turns on and the data voltage is applied to the pixel, the sub-pixels 901 and 902 are charged with the data voltage. When the gate voltage turns off, the voltage charged at the respective sub-pixels 901 and 902 drops as much as the kickback voltage. The kickback voltage at the A terminal and the kickback voltage at the B terminal are expressed by Equation 1.
VkA
=
Cp
×
Δ
Vgate
C
max
+
Clc
+
Cp
=
Cp
×
Δ
Vgate
C
min
+
ΔC
+
Clc
+
Cp
VkB
=
Cp
×
Δ
Vgate
C
min
+
Clc
+
Cp
=
Cp
×
Δ
Vgate
C
min
+
Clc
+
Cp
[
Equation
1
]
In Equation 1, Cp indicates parasitic capacitance, ΔVgate indicates the voltage difference between the on and off sections of the gate voltage, Cmax indicates the maximum capacitance of the variable capacitor, Cmin indicates the minimum capacitance of the variable capacitor, Clc indicates the liquid crystal capacitance, and ΔC indicates the difference between the maximum capacitance Cmax and the minimum capacitance Cmin.
As the kickback voltage at the A terminal has a relatively lower value due to the difference in capacitance ΔC, the voltage of the high gray sub-pixel 901 that drops when the gate voltage turns off is relatively low so that it exhibits a high gray. Equation 1 is valid when the data voltage is higher than the common voltage Vcom.
Meanwhile, a voltage that is lower than the common voltage Vcom is applied as the data voltage by way of inversion driving. The variable capacitor Cst_h of the high gray sub-pixel 901 has the minimum capacitance Cmin because the data voltage is lower than the common voltage Vcom, while the variable capacitor Cst_l of the low gray sub-pixel 902 has the maximum capacitance Cmax. As a result, the kickback voltage at the A terminal is relatively low, and the kickback voltage at the B terminal is relatively high. Therefore, when the gate turns off, the voltage drops much more at the A terminal so that the high gray sub-pixel 901 exhibits a higher gray.
The case where the variable capacitor is formed with a thin film transistor will now be described in detail.
FIG. 4 is an equivalent circuit diagram of a pixel in a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 5 and FIG. 6 are cross-sectional views of the variable capacitors shown in FIG. 4 . FIG. 7 is a voltage-capacitance graph of the variable capacitors shown in FIG. 6 . The numerical reference 110 in the figures represents a substrate.
As shown in FIG. 4 , with a liquid crystal display according to an exemplary embodiment of the present invention, pixel 900 includes two sub-pixels 901 and 902 . The sub-pixels 901 and 902 include thin film transistors Qs_h and Qs_l, liquid crystal capacitors Clc_h and Clc_l, and variable capacitors Ct_h and Ct_l, respectively. The respective sub-pixels 901 and 902 receive the same voltage through a data line Dj, but the voltages applied to the liquid crystal capacitor Clc_l and Clc_h are different depending upon the operation of the variable capacitors Ct_l and Ct_h. As a result, when images are displayed by way of the liquid crystal capacitors Clc_l and Clc_h, they express different grays. The sub-pixel 902 expressing a relatively lower gray will be referred to as the low gray sub-pixel, and the sub-pixel 901 expressing a relatively higher gray will be referred to as the high gray sub-pixel.
The relationship of the respective sub-pixels will be first described in detail.
The high gray sub-pixel 901 includes a thin film transistor Qs_h with a control terminal connected to a gate line Gi and an input terminal connected to the data line Dj. A liquid crystal capacitor Clc_h and a variable capacitor Cst_h are respectively connected to the output terminal of the thin film transistor Qs_h.
The liquid crystal capacitor Clc_h includes a pixel electrode (not shown), a common electrode (not shown), and a liquid crystal layer (not shown) interposed between the pixel and common electrodes. The pixel electrode, which is connected to the output terminal of the thin film transistor Qs_h, receives a data voltage, and the common electrode receives a common voltage Vcom. When an electric field is generated from the voltage difference between the pixel and common electrodes, the liquid crystal molecules reorient so that the light polarization is modified quantitatively and an image is displayed.
As shown in FIG. 6 , the variable capacitor Ct_h is formed with a thin film transistor including a gate electrode 124 , a semiconductor layer 150 , a source electrode 173 , and a drain electrode 175 . The source and drain electrodes 173 and 175 are electrically connected to each other. A gate insulating layer 140 is interposed between the semiconductor layer 150 and the gate electrode 124 . Ohmic contact layers 163 and 165 are formed between the drain electrode 175 and the semiconductor layer 150 as well as between the source electrode 173 and the semiconductor layer 150 . With the high gray sub-pixel 901 , the gate electrode 124 , which is connected to the output terminal of the thin film transistor Qs_h, receives a data voltage, and the source and drain electrodes 173 and 175 receive a common voltage Vcom. An arbitrary voltage V 0 may be applied to the target instead of the common voltage Vcom. It is illustrated with the indication Vcom or V 0 in FIG. 4 that either the common voltage Vcom or the arbitrary voltage may be applied to the target. With the variable capacitor Ct_h according to an exemplary embodiment of the present invention, when the voltage applied to the gate electrode 124 reaches or exceeds a predetermined voltage, a channel is formed at the semiconductor layer 150 according to the characteristic of the thin film transistor. In this case, the semiconductor layer 150 functions as a conductor so that a variable capacitor Ct_h is formed at a region of the semiconductor layer 150 , the source electrode 173 , and the drain electrode 175 overlapped with the gate electrode 124 . The operation characteristic of the variable capacitor Ct_h of the high gray sub-pixel 901 will be described more specifically with reference to FIG. 7 .
With the graph of FIG. 7 , the horizontal axis represents the voltage applied to the gate, and the vertical axis represents the capacitance stored at the thin film transistor. With the thin film transistor shown in FIG. 7 , the source and drain electrodes are electrically connected to each other while being grounded. The width W of the thin film transistor in one embodiment, is 200 μm, the length L thereof 50 μm, the length of the gate electrode overlapping with the source and the drain electrodes to be 10 μm, and the thickness of the insulating layer 450 nm.
Experiments that the cumulated capacitance of the thin film transistor quickly rises along a predetermined voltage (indicated by dotted lines in the drawing), and gradually reaches a predetermined capacitance Cmax. Accordingly, when the voltage applied through the gate electrode 124 reaches a predetermined value, the thin film transistor has the maximum capacitance Cmax.
Furthermore, with the high gray sub-pixel 901 , a parasitic capacitance Cph is formed between the gate line Gi and the output terminal of the thin film transistor Qs_h.
Similarly, the low gray sub-pixel 902 includes a thin film transistor Qs_l with a control terminal connected to the gate line Gi and an input terminal connected to the data line Dj. A liquid crystal capacitor Clc_l and a variable capacitor Ct_l are connected to the output terminal of the thin film transistor Qs_l.
The liquid crystal capacitor Clc_l includes a pixel electrode (not shown), a common electrode (not shown), and a liquid crystal layer (not shown) interposed between the pixel and common electrodes. The pixel electrode, which is connected to the output terminal of the thin film transistor Qs_l, receives a data voltage, and the common electrode receives a common voltage Vcom. An electric field is generated from the voltage difference between the pixel and common electrodes, and the liquid crystal molecules reorient to modify the light polarization is quantitatively, thus displaying an image.
Similarly, as shown in FIG. 5 , the variable capacitor Ct_l is formed with a thin film transistor including gate electrode 124 , semiconductor layer 150 , source electrode 173 , and drain electrode 175 . The source and drain electrodes 173 and 175 are electrically connected to each other. The gate insulating layer 140 is interposed between the semiconductor layer 150 and the gate electrode 124 . Ohmic contact layers 163 and 165 are formed between the drain electrode 175 and the semiconductor layer 150 as well as between the source electrode 173 and the semiconductor layer 150 . With the low gray sub-pixel 902 , the source and drain electrodes 173 and 175 , which are connected to the output terminal of the thin film transistor Qs_l, receive a data voltage, and the gate electrode 124 receives a common voltage Vcom. An arbitrary voltage V 0 , instead of the common voltage Vcom, may be applied to the target, and the arbitrary voltage V 0 is indicated separately in FIG. 4 . However the variable capacitor Ct_l has a characteristic according to an exemplary embodiment of the present invention, when a predetermined voltage is applied to the gate electrode 124 of the thin film transistor, it does not turn on because no channel is formed at the semiconductor layer 150 . Consequently, as shown in FIG. 5 , a variable capacitor Ct_l is formed where the source and drain electrodes 173 and 175 overlap the gate electrode 124 . In case ohmic contact layers 163 and 165 are formed, such a variable capacitor may be formed where the ohmic contact layers 163 and 165 and the source and drain electrodes 173 and 175 overlap the gate electrode 124 . In the case of the low gray sub-pixel 902 , a constant voltage is applied to the gate electrode 124 .,
Furthermore, a parasitic capacitance Cph is formed between the gate line Gi and the output terminal of the thin film transistor Qs_l.
As described above, the variable capacitor Ct_l of the low gray sub-pixel 902 shown in FIG. 5 and the variable capacitor Ct_h of the high gray sub-pixel 901 shown in FIG. 6 have different storage capacitance because the overlapping areas differ from each other even though other conditions are the same. Consequently, the kickback voltages are different for the two sub-pixels, even though the same data voltage is applied thereto, resulting in different luminance.
FIG. 4 to FIG. 6 illustrate the structure of the variable capacitor where the source and drain electrodes of the thin film transistor are electrically connected to each other. With the usage of the variable capacitor where the source and drain electrodes of the thin film transistor are electrically connected to each other, the device characteristics are identified so as to test the reliability thereof. This is illustrated in FIG. 8 and FIG. 9 .
FIG. 8 and FIG. 9 illustrate the voltage-current characteristics under stress of the variable capacitors shown in FIG. 4 .
FIG. 8 illustrates the case with DC voltages driving the gate, and FIG. 9 illustrates the case with AC voltages driving the gate. In FIG. 8 and FIG. 9 , the horizontal axis represents the voltage difference between the gate and source electrodes, and the vertical axis represents the electric current flowing along the drain electrode.
FIG. 8 shows that the current-voltage curve before the stress application is different from after the stress applied under 15 V DC for three hours.
By contrast, FIG. 9 shows that the voltage-current curve before the AC voltage stress application overlaps the curve after the three hour stress under the ±15V AC voltage.
Because the liquid crystal display is commonly inversion-driven to prevent device degradation, there is no problem in forming and using the variable capacitors shown in FIG. 4 with the inversion-driving.
A variable capacitor according to another exemplary embodiment of the present invention will now be described in detail.
FIG. 10 and FIG. 11 are cross-sectional views of variable capacitors according to another exemplary embodiment of the present invention.
The variable capacitors shown in FIG. 10 and FIG. 11 may include all the other structural features of those shown in FIG. 1 . With a liquid crystal display according to an exemplary embodiment of the present invention, pixel 900 includes two sub-pixels 901 and 902 , which in turn include thin film transistors Qs_h, Qs_l, liquid crystal capacitors Clc_h and Clc_l, and variable capacitors Ct_h and Ct_l, respectively.
The variable capacitor Ct_h of the high gray sub-pixel 901 is illustrated in FIG. 11 , and the variable capacitor Ct_l of the low gray sub-pixel 902 is illustrated in FIG. 10 .
As shown in FIG. 11 , the variable capacitor Ct_h of the high gray sub-pixel 901 includes gate electrode 124 , semiconductor layer 150 , and source electrode 173 , but there is no drain electrode like in a common thin film transistor. The gate insulating layer 140 is formed between the semiconductor layer 150 and the gate electrode 124 . Furthermore, an ohmic contact layer 163 is formed between the source electrode 173 and the semiconductor layer 150 . In the high gray sub-pixel 901 , the gate electrode 124 , which is connected to the output terminal of the thin film transistor Qs_h, receives a data voltage, and the source and drain electrodes 173 and 175 receive a common voltage Vcom. An arbitrary voltage V 0 may be applied to the target instead of the common voltage Vcom. However in the variable capacitor Ct_h shown in FIG. 11 , when the voltage applied to the gate electrode 124 reaches or exceeds a predetermined voltage, the semiconductor layer 150 operates like a conductor according to the characteristic of the thin film transistor. In this case, as shown in FIG. 11 , a variable capacitor Ct_h is formed where the semiconductor layer 150 and the source electrode 173 overlap the gate electrode 124 .
The low gray sub-pixel 902 includes a variable capacitor Ct_l shown in FIG. 10 . The variable capacitor Ct_l of the low gray sub-pixel 902 includes gate electrode 124 , semiconductor layer 150 , and source electrode 173 , but there is no drain electrode like in a common thin film transistor. The gate insulating layer 140 is formed between the semiconductor layer 150 and the gate electrode 124 . The ohmic contact layer 163 is formed between the source electrode 173 and the semiconductor layer 150 . In the low gray sub-pixel 902 , the source electrode 173 , which is connected to the output terminal of the thin film transistor Qs_l, receives a data voltage, and the gate electrode 124 receive a common voltage Vcom. An arbitrary voltage V 0 , instead of a common voltage Vcom, may be applied to the target. In the variable capacitor Ct_l according to an exemplary embodiment of the present invention, a predetermined voltage is applied to the gate electrode 124 according to the characteristic of the thin film transistor, the thin film transistor does not turn on because no channel is formed at the semiconductor layer 150 . Consequently, in FIG. 10 , a variable capacitor Ct_l is formed where the source electrode 173 overlaps the gate electrode 124 . When ohmic contact layer 163 is formed, such a variable capacitor may be formed where the ohmic contact layer 163 and the source electrode 173 overlap the gate electrode 124 .
As described above, the variable capacitor Ct_l of the low gray sub-pixel 902 shown in FIG. 10 and the variable capacitor Ct_h of the low gray sub-pixel 901 shown in FIG. 11 have different storage capacitance as the overlapped areas thereof differ from each other even though other conditions are the same. Consequently, the kickback voltages are formed differently at the respective sub-pixels, even though the same data voltage is applied thereto, resulting in different luminance.
The variable capacitance structure shown in FIG. 10 and FIG. 11 differs from that shown in FIG. 5 and FIG. 6 in that the variable capacitors Ct_l and Ct_h in the two sub-pixels 901 and 902 are differently controlled. That is, the variable capacitors Ct_h of the high gray sub-pixels 901 shown in FIG. 6 and FIG. 11 differ little from each other, but the variable capacitors Ct_l of the low gray sub-pixels 902 significantly differ from each other in that the capacitance in FIG. 10 is reduced to half that in FIG. 5 (see the double ended arrows) Therefore, it is possible in the formation of a display device, to use the structure shown in FIG. 10 and FIG. 11 in case it is desirable to enlarge the dimensional difference between the variable capacitors Ct_l and Ct_h of the two sub-pixel 901 and 902 , or to use the structure shown in FIG. 5 and FIG. 6 in case it is desirable to reduce the dimensional difference between those variable capacitors Ct_l and Ct_h. Furthermore, it is possible in designing a thin film transistor to alter the dimension of electrodes and channels to control the difference between the variable capacitors Ct_l and Ct_h of the high gray sub-pixel 901 and the low gray sub-pixel 902 , thereby obtaining enhanced lateral visibility.
The pixel structure of the liquid crystal panel formed in the liquid crystal display is described above based on the circuit diagram. A signal controller, a data driver, a gate driver, a liquid crystal layer, and the like, which are not described above, may be formed in various manners.
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A vertical alignment liquid crystal display includes two sub-pixels each with a variable capacitor. A pixel is bisected into a high gray sub-pixel and a low gray sub-pixel through forming a variable capacitor at each sub-pixel. With this structure, the sub-pixels express different grays so that lateral visibility is enhanced. It is not required in bisecting a pixel into two sub-pixels to form separate wires for applying different signals thereto, and the amount of data to be processed at the driver for driving the display device is reduced. Furthermore, a pixel is bisected into two sub-pixels with variable capacitors in a simplified manner, and it is not required to form additional wires and elements, so the aperture ratio is enhanced. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. application Ser. No. 13/420,142, filed Mar. 14, 2012.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
[0003] Not Applicable
TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION
[0004] The present invention is in the technical field of masonry veneer products, and includes a system using such products. More particularly, the present invention is in the technical field of masonry veneer products installed without a scratch coat and lath system.
BACKGROUND OF THE INVENTION
[0005] As described in copending U.S. patent application Ser. No. 13/420,142, which is incorporated herein by reference in its entirety, Masonry veneer systems are commonly used for exterior cladding, as architectural or aesthetic features on residential and commercial buildings.
[0006] As described in detail by the Masonry Veneer Manufacturers Association (MVMA), proper installation of stone on a framed building requires the installation of a weather resistant barrier (WRB), then application of a lath secured to the framing with corrosion resistant fasteners and a nominal ½ inch scratch coat. The lath must be properly applied to the wall in order to avoid intrusion of water, and to provide an acceptable structure to which the cladding will be adhered. The lath must be corrosion resistant, applied in an overlapping fashion, and with a corrosion resistant nail that penetrates the studding according to the MVMA recommendations. Additionally, the scratch coat must be applied using a correct mortar at the proper moisture content and thickness, embedded properly in the lath, allowed to cure to “thumb dry”, the scratched to provide grooves, and allowed to cure. These additional products and steps add cost, additional labor and provide opportunities for human error, which can result in a poor installation and future problems. The installation of the WRB, lath and scratch coat must be performed up to 48 hours or more before the installation of the veneer product, allowing the scratch coat to properly cure. Further details are set forth by the MVMA.
[0007] Once the scratch coat is properly applied and cured, adhered concrete masonry veneer (ACMV) products are then adhered to the scratch coat using a mortar applied to the ACMV. The MVMA guidelines recommend that the scratch coat should be moist cured to prevent cracking, and that both the scratch coat and the ACMV should be “dampened” when applying the ACMV, adding additional requirements on the installer. The installer typically will take individual ACMV products, “butter” the back of each individual product with mortar, and apply the “buttered” product to the scratch coat, forcing the mortar into the scratch coat to adhere the ACMV to the wall. The consistency of the scratch coat, mortar and skill of the installer each play a role in the reliability of the installation. Additionally, the installation should not be performed during rain or cold weather, thus limiting the time available (and time delay) for completion of the building. These all add to cost and customer dissatisfaction during the construction process.
[0008] ACMV products are typically installed as discrete individual stones or brick adhered to a scratch coat on the exterior of a building as described above. Stones are typically installed from the top of the building, and the wall is covered in a downward direction. If the wall is struck (e.g. if drywall is installed on the interior of the building) before the mortar is cured, the stone may be dislodged from the wall. This creates re-work for the installer, or partially dislodged stones may become loose at a later date.
[0009] An optional installation technique described in the MVMA guidelines includes a rainscreen drainage plane system, which provides a space to permit incidental water to escape. The recommended ways to provide this space include a drainage mat, formed polymer sheeting (such as Delta®-Dry Stucco and Stone, available from Cosella-Dorken, ref. http://www.cosella-dorken.com), strapping or furring to provide the recommended MVMA air gap of 3/16 to ¾ inch. These systems allow moisture to escape from behind the veneer, but add additional material and labor cost, time and complexity during installation of the ACMV product, and are not used in many installations.
[0010] A panelized veneer product, Versetta Stone, is sold by Boral Stone, LLC. (http://masonry.owenscorning.com/versettastone). These panelized veneer products are secured to the exterior of a building using mechanical fasteners driven through a flange embedded in the top of the veneer product. These systems reduce some of the issues with the adhered ACMV products, because the lath, scratch coat and adhesive mortar can be eliminated in many installations of these panelized veneer products. However, these panelized veneer products are relatively large (typically about 8-10 inches high and approximately 32-36 inches wide) and have a limited drainage plane gap. While this enables fast installation on structures where penetrations are not present (such as windows or outlets) or corners, the presence of these penetrations on most buildings results in a large number of panels being trimmed and a fairly large amount of waste (Boral's installation instructions instructs an installer to initially estimate 10% scrap). The large number of cuts takes time and produces excess waste. Additionally, these products are more expensive to manufacture, and the designs present challenges in manufacturing.
[0011] Accordingly, it would be desirable to provide an improved product and system for installing veneer products and to eliminate the lath and scratch coat.
SUMMARY OF THE INVENTION
[0012] In accordance with the purposes of the present invention as described herein, an improved masonry veneer product (“MVP”) and system (“MVS”) are provided. Such a product and system includes a bracket embedded in the product, the bracket having a first end for securing the upper end of the product to a building. In one embodiment, the bracket also creates an integral air gap behind the product for the escape of moisture. The bracket may include a second end for retaining the bottom end of the product to the building through an interference fit to an adjacent MVP. The system further includes a projection between adjacent MVP to impede moisture from passing between MVP's, and a WRB installed adjacent the structure and air gap to keep moisture from entering the structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 provides a front view of a pair of masonry veneer products according to the present invention;
[0014] FIG. 2 provides a front view of a corner masonry veneer product according to the present invention;
[0015] FIGS. 2A and 2B provide isometric views of a drip ledge corner product according to the present invention;
[0016] FIG. 3 provides an isometric view of a masonry veneer product according to the present invention;
[0017] FIG. 4 provides an isometric view of a first wire retainer according to the present invention;
[0018] FIG. 5 provides an isometric view of a second wire retainer according to the present invention;
[0019] FIG. 6 provides an isometric view of a masonry veneer product according to the present invention having a long width dimension;
[0020] FIG. 7 provides an isometric view of a masonry veneer product according to the present invention useful as an accessory;
[0021] FIG. 8 provides an isometric view of a masonry veneer product installed into a starter strip over a WRB according to the present invention;
[0022] FIG. 9 provides an end view of a starter strip profile according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring now to FIG. 1 there are shown a pair of masonry veneer products 10 , 10 ′ illustrated schematically and described herein typically as a dry stack stone product body 12 , similar to a typical box material in appearance. However, the new MVP and MVS have additional inventive features as described herein. The present invention could be applied to nearly any texture of manufactured stone or brick, but is primarily illustrated with a dry stack installation for the sake of simplicity (and as a representative installation). Although not illustrated, one skilled in the art appreciates that an embodiment of the present invention may be used with a grouted texture, and would preferably include a flange on one of the top and bottom of the stone and a second flange on either the left or right end, the flanges each serving as a ledge for a grouted joint. One skilled in the art could modify the current design to utilize the present invention with other textures and configurations.
[0024] The embodiment shown in FIG. 1 includes a pair of brackets 14 , 14 ′ embedded in the product body 12 . Each bracket includes a top end 16 and bottom end 18 . The top end 16 is illustrated as having a looped construction forming an eye for receiving a fastener 40 as illustrated in FIG. 8 . The ends 16 , 18 are designed to extend and nest under an adjacent stone as illustrated in FIG. 1 at 21 . Each end preferably includes a curved shape 17 , 19 as illustrated in FIGS. 4 and 5 for holding the body 12 away from the wall to create an air gap for drainage and to allow for deflection of the ends 16 , 18 when attached to the wall. In a preferred embodiment as illustrated in FIG. 4 , the wire 14 includes two attachment eyes 25 , 26 at the bottom end 18 and two attachment eyes 27 , 28 at the top end 16 , formed in a unitary bracket 14 . A lateral connector 13 is provided to enable the formation of the bracket into a single piece, preferably as a unitary construction, to enable efficient manufacture of the product 10 . Although shown connecting the top ends 16 , another embodiment includes a connector for connecting the bottom ends or intermediate portions 20 .
[0025] As further illustrated in FIG. 3 , the bracket 14 is embedded into the stone body 12 , with an intermediate portion 20 as shown in FIGS. 4 and 5 . The intermediate portion 20 is embedded in the product body 12 a depth sufficient to ensure adequate engagement to support the stone body 12 when attached to a building (not shown), preferably for the life of the building. The depth and shape may affect the pullout strength, and should be coordinated with the size, shape and weight of the product. In a preferred embodiment, the embedded depth is approximately ¾-1 inch, but may be more or less depending on the surface area of the bracket, the characteristics of the body composition, and the size and shape of the body. In one embodiment the depth is ½ inch. In a heavier product, the depth may be 1.5 inch or more, depending on requirements. The brackets 14 penetrate the stone body 12 to a depth that provides sufficient engagement between the bracket and cured concrete stone, but also which retains a thickness of concrete that will ensure the face of the stone body 12 does not expose the wire or fracture during the life of the building. The brackets 14 are preferably formed from a wire that is corrosion resistant, such as a stainless steel or galvanized steel, and having sufficient strength and sufficient stiffness to not deform and to provide the installation with an interference fit at the bottom as described below. The bracket 14 should be rigid enough to withstand handling, packaging, transport and installation without excessive deformation. In another embodiment, the brackets 14 are formed from a fiberglass material, or any material known to one skilled in the art that is not corroded and will support the masonry product 10 . In yet another embodiment (not shown), the brackets 14 are stamped from sheet metal or formed or molded from another non-corrosive material in a more flattened cross section. One skilled in the art appreciates the bracket preferably has adequate strength and shape retention or memory.
[0026] As shown in the embodiment illustrated in FIGS. 1 and 3 , the product may include water shedding feature, which is described herein to include a flashing lip 22 along the top surface 29 of the stone body 12 . This lip 22 is intended to inhibit the passage of moisture, such as wind driven rain, between the stone body 12 and an adjacent stone 10 ′ as illustrated in Fig. In such an embodiment, each stone body 12 may also include a corresponding recess 24 on the bottom surface 30 of the stone body 12 to correspond with the opposing lip 22 of the adjacent stone. This lip 22 and recess 24 also serve to obscure a view of the WRB installed beneath the stone to create a visually appealing dry stack installation. It also enables easier leveling during installation.
[0027] Although not illustrated here, the lip 22 may contact the body within the recess, thereby setting the gap between the products. In a similar manner, each stone preferably includes a lip along one end of the stone body, and a corresponding recess along the opposite end of the stone body, which will inhibit moisture intrusion, obscure visibility behind the product, and set the side to side gap.
[0028] While the lip and recess 22 , 24 are illustrated in FIGS. 1 and 3 as an angled or chamfered protrusion and recess, one skilled in the art appreciates that while not illustrated as such, the lips 22 , 24 could be simple ridge, a rabbet, shiplap, or other type of configuration that provides a moisture block and an improved line of sight.
[0029] As illustrated in the embodiment of FIG. 3 , the bracket 14 includes a first protrusion 34 formed in the bracket 14 . The protrusion extends below the back surface 32 of the stone body 12 to bear against the structure 39 illustrated in FIG. 9 and create an air gap G 1 under the product 10 when installed on a structure, preferably installed over a WRB 38 . In the illustrated embodiment, the bracket 14 includes a bend 36 which holds the top end 16 away from the structure 39 and WRB 38 to create a second gap G 2 . When the bracket 14 is secured through the WRB 38 to the structure 39 as illustrated in FIG. 8 , the top end is urged by the fastener 40 toward the structure 39 . This force on the top end 16 acts as a lever, which urges the opposite second end 18 of the bracket 14 away from the structure 39 and toward the back surface 32 ′ of a second body, such as an adjacent product 10 ′, or into a channel on e.g. a starter strip 42 . Because the second end 18 is wedged below the lower product 10 ′, this causes a second protrusion 35 at the bottom end 18 to be held securely against the structure 39 and therefore the product is secured both at the top by the nail and at the bottom by a wedging action against the second product 10 ′. In a preferred embodiment, the top end is positioned approximately ⅛ inch further away from the structure to ensure the wedging action occurs. This dimension can be modified depending on the stiffness of the wire and the surface against which it bears to provide a gap greater than the height off the wall to enable a cam locking action.
[0030] As illustrated in FIG. 3 , in a preferred embodiment, the gap under the top GT is approximately ½ inch and the gap under the bottom GB is approximately ⅜ inch. One skilled in the art appreciates this dimension may be modified based on the air gap desired, concrete penetration and the deformation of the bracket 14 . As illustrated in FIG. 1 the top end 16 preferably extends a distance B 2 above the body 12 and bottom end 18 extends a distance B 1 below the body 12 . In a preferred embodiment B 1 extends approximately ½ inch further than B 2 . In one embodiment B 1 is approximately 1⅝ inch and B 2 is approximately 1⅛ inch. In another embodiment, B 1 is approximately 1¼ inch and B 2 is approximately ¾ inch. One skilled in the art appreciates this dimension may be changed to increase or decrease overlap depending on the nature of the wire, the size of the stone, and other manufacturing and installation factors, and in some embodiments, the dimensions may be the same or opposite to reflect the overall design requirements. One skilled in the art appreciates that the overlap can be lengthened to the height of the stone or more if designed with no interference, and greater overlap may provide a more stable wall.
[0031] In another embodiment (not illustrated), the top end of the bracket 14 does not have a bend 36 , and the bottom end 18 of the bracket is bent to lie in a plane above the back surface 32 of the stone body 12 , so the bottom end 18 is installed under an adjacent product (not shown) simply using an interference fit. This interference may be at least 1 mm and could be 2, 3, 4, or 5 mm or more, depending on the stiffness of the bracket. Accordingly, the configuration of the bottom bracket illustrated in FIG. 2 may be used with or without the bent configuration of the top end 16 as illustrated in FIG. 2 . Additionally, the second end 18 may be wedged against another body, such as a starter strip or an accessory, such as a ledge. In certain applications, it may be sufficient to fasten the second end using adhesives, nails, stapes, screws or the like as a substitute for the second body. While the protrusions are illustrated herein as bent wires, one skilled in the art appreciates that a different configuration could include a molded protrusion, a weldment, or other configurations to provide the desired gap.
[0000] Page 10 Top—The overlap of the wire can be greater or less so I would broaden the claim dimensions. The overlap can be the entire length of the stone or more in reality if designed with no interference. We suggest that it should be a minimum of a half inch and the longer the better to provide a stable wall.
Page 10 bottom—Concerning the word “wedged” as it relates to the bottom clip to the starter strip, we should say that “bending and wedging” the bottom legs into a groove of the starter strip provide the stability for the stone when the top clip eyelets of the stone are screwed in to the wall
[0032] A system including the product 10 described above preferably includes a building structure 39 such as a frame and sheathing or concrete structure, a weather resistant barrier 38 installed over the structure (similar in nature and installation to that specified by the MVMA), a plurality of products 10 attached to the structure over the WRB 38 and attached to the structure 39 using fasteners 40 projecting through the brackets 14 . The fasteners 40 are preferably non-corrosive, such as galvanized roofing nails, screws or staples; provided however that the fasteners must provide sufficient strength to secure the product 10 to the structure 39 for the life of the structure.
[0033] In one embodiment, installation begins from the bottom of the building. In such an instance, a starter strip 42 is installed to the building in a level manner. A preferred starter strip is illustrated in FIG. 9 . The starter strip 42 preferably includes a recess 44 to receive the bottom 18 of the brackets 14 . The starter strip preferably includes weep holes 46 at the bottom of the recess 44 to enable water to drain. The recess 44 preferably includes a lead angle 48 to enable easy installation of the bracket 14 and preferably narrows to a line to line or interference fit to wedge the bracket 14 and hold it in place. In one embodiment, the lead angle is approximately twenty degrees, and the recess has a bottom radius R 1 of 0.06 inch for a 0.12 diameter wire, and a depth L 1 of approximately ½ inch. Products having characteristics similar to the starter strip are also preferably used as flashing around windows and other openings. The starter strip 42 is preferably made from galvanized steel, aluminum, PVC or any common noncorrosive building material used in similar applications. Furthermore, the bottom of the bracket may experience bending and wedging as the bottom legs are fit into the recess of the starter strip and the brackets are secured to the wall. e
[0034] The starter strip 42 also includes a back portion 50 which extends under the WRB 38 to ensure water does not enter under the WRB, to comply with ASTM requirements. In a preferred embodiment the back portion 50 has a height L 2 of 3.5 inches to satisfy ASTM. In another embodiment, 2 inches may be sufficient. The overlap may be less in some situations or may be more, but practicality limits one is normally acceptable. In another embodiment, a simple j-channel or other starter is used with the products 10 of the present invention. Similarly, one skilled in the art appreciates that either a starter strip or weep screed should provide ventilation at the bottom, and therefore accommodations should be made to provide for air passage. Once the first row is secured to the wall using the starter strip 42 and the top end 16 of the brackets is secured as described above, the second row is installed by inserting the bottom ends 18 of the second row of products behind the rear surface 32 of the first row of products previously installed. Then the top end of successive rows of the product being installed is pushed against the structure 39 and secured at the top end 16 as described above.
[0035] The top row of the product may be capped or may extend to the soffit. It is desirable to include an air gap where possible to provide for air flow. Where water drainage does not permit this, MVMA details may be followed. Where the product extends to the soffit, an installation similar to typical brick installation may be performed, i.e. the soffit may be installed after the product is installed. Alternatively the soffit j-channel may include a spacer against the wall to provide for air flow at the top of the wall.
[0036] Although not illustrated, in one embodiment, after the product is secured to the structure, a bead of caulk or other material is optionally installed on the product along one of the top and bottom, plus one of the ends, so that the joint between adjacent products is filled with the material to provide a substantially effective water seal. In yet another embodiment, a bead of caulk or foam dam is provided on the top or bottom and one end of each stone at the factory to provide a substantially watertight joint between adjacent products without a field-applied caulk.
[0037] One skilled in the art appreciates that while not illustrated here, a grout product may optionally be installed between adjacent products for certain textures. Such a grout is preferably flexible, so that it can perform for an extended period without cracking. Such a grout is also preferably water resistant to minimize the amount of water that enters between adjacent products. Additionally, a grout may be used with the flanged design described above.
[0038] As illustrated in FIG. 3 , the product 10 preferably includes a single bracket 14 , but one skilled in the art appreciates that more than one bracket may be utilized to provide additional support and attachment, or to facilitate manufacture. The nature of the product (size, weight) and the nature of the brackets, fasteners and structure and environment can affect these requirements.
[0039] As illustrated in FIGS. 2, 2A 6 and 7 , the invention is also applied to corners and accessories, such as drip ledge corners, trim stones, keystones, ledges, light fixtures, outlets, column wraps and other products. In the case of corners, in one embodiment shown in FIG. 2 , only one side of the stone corners are attached to the structure, and a spacer is provided on the backside of the return to provide a consistent air gap and exterior thickness. As shown in FIG. 2 , the corner 60 includes a long leg 62 and a return leg 64 . The bracket 14 is used to attach the long leg 62 to the building and the short leg 64 is supported as part of the body. While the corner 60 is illustrated with the top 66 installed so the return is on the left side, the corner 60 could be inverted so the bottom 68 is installed upwardly so the return 66 is on the right side of the corner 60 . Thus, the corners 60 are reversible. Preferably the reversible corners have a reversible clip that is embedded in the concrete to allow for ease of ordering materials, using as left and right corners and staggered joints during installation to give a more authentic stone look.
[0040] As illustrated in FIG. 2B , a corner may include two wires 214 , 214 ′ to ensure both legs are sufficiently supported. In this example, the corner may be a ledge corner. In a similar manner, FIG. 6 illustrates an elongate product 10 ″having two brackets 614 , 614 ′ to support the elongate product. While not limiting, in this illustration, the elongate product 10 ″ may comprise a ledge piece. FIG. 7 illustrates another accessory piece 70 including brackets 714 according to the principles of this invention. Referring to FIGS. 7 and 2B , one skilled in the art appreciates that one can use single or double clips or a combination of single and double clips and can be installed in vertical or horizontal configurations. This principal can be applied to other accessories including trim stones, surrounds, drip ledge corners, light boxes and other accessories.
[0041] In another embodiment, the installation instructions teach the installer to set a gap manually, or to use separate spacers, such as foam or molded parts. In another embodiment, the instant invention is applied to a panelized product. In such a case, it may be necessary to utilize a greater number of brackets to adequately support and secure the panelized product due to its size and weight.
[0042] One embodiment of the present invention is applied to individual stones or bricks. This makes installation simple, as fewer products will be cut and less scrap created. Furthermore, it avoids the potential that an installer will align the panels to create unsightly lines or an unattractive panelized wall. Additionally, the individual products also make it simpler to create accessory products that are compatible with this system. As noted above, however, applicant envisions that a panelized system could utilize the present invention, either alone or in combination with the individual products as described above.
[0043] While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention. | A veneer product and system includes a body having an aesthetic front surface and a back surface for installation adjacent the building. The body has a top side and a bottom side and a bracket attached to body and projecting away from the back surface of the body, the bracket further comprising a first end adjacent the top side for attachment to the building and a first protrusion for positioning the back surface a predetermined distance from the building and a second end having a second protrusion for positioning the bottom of the back surface a predetermined distance from the building and a bottom projection adjacent the bottom side for engagement with a second body to retain the bottom end of the veneer product. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims benefit of U.S. Provisional Patent Application No. 61/428,810, filed Dec. 30, 2010, entitled GAS TURBINE ENGINE AND COMBUSTION LINER, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to gas turbine engines, and more particularly, to gas turbine engine combustion liners.
BACKGROUND
[0003] Gas turbine engine combustion liners that effectively withstand high temperature conditions and provide reduced acoustics remain an area of interest. Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.
SUMMARY
[0004] One embodiment of the present invention is a unique gas turbine engine combustion liner. Another embodiment is a unique gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and gas turbine engine combustion liners. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
[0006] FIG. 1 schematically illustrates some aspects of a non-limiting example of a gas turbine engine in accordance with an embodiment of the present invention.
[0007] FIG. 2 schematically illustrates some aspects of a non-limiting example of a gas turbine engine combustion liner in accordance with an embodiment of the present invention.
[0008] FIG. 3 schematically illustrates some aspects of a non-limiting example of a liner wall structure in accordance with an embodiment of the present invention.
[0009] FIG. 4 schematically illustrates some aspects of a non-limiting example of another liner wall structure in accordance with an embodiment of the present invention.
[0010] FIG. 5 schematically illustrates some aspects of a non-limiting example of yet another liner wall structure in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0011] For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nonetheless be understood that no limitation of the scope of the invention is intended by the illustration and description of certain embodiments of the invention. In addition, any alterations and/or modifications of the illustrated and/or described embodiment(s) are contemplated as being within the scope of the present invention. Further, any other applications of the principles of the invention, as illustrated and/or described herein, as would normally occur to one skilled in the art to which the invention pertains, are contemplated as being within the scope of the present invention.
[0012] Referring to the drawings, and in particular FIG. 1 , there are illustrated some aspects of a non-limiting example of a gas turbine engine 20 in accordance with an embodiment of the present invention. In one form, engine 20 is a propulsion engine, e.g., an aircraft propulsion engine. In other embodiments, engine 20 may be any other type of gas turbine engine, e.g., a marine gas turbine engine, an industrial gas turbine engine, or any aero, aero-derivative or non-aero derivative gas turbine engine. In one form, engine 20 is a two spool engine having a high pressure (HP) spool 24 and a low pressure (LP) spool 26 . In other embodiments, engine 20 may include three or more spools, e.g., may include an intermediate pressure (IP) spool and/or other spools. In one form, engine 20 is a turbofan engine, wherein LP spool 26 is operative to drive a propulsor 28 in the form of a turbofan (fan) system, which may be referred to as a turbofan, a fan or a fan system. In other embodiments, engine 20 may be a turboprop engine, wherein LP spool 26 powers a propulsor 28 in the form of a propeller system (not shown), e.g., via a reduction gearbox (not shown). In yet other embodiments, LP spool 26 powers a propulsor 28 in the form of a propfan. In still other embodiments, propulsor 28 may take other forms, such as one or more helicopter rotors or tilt-wing aircraft rotors.
[0013] In one form, engine 20 includes, in addition to fan 28 , a bypass duct 30 , a compressor 32 , a diffuser 34 , a combustor 36 , a high pressure (HP) turbine 38 , a low pressure (LP) turbine 40 , a nozzle 42 A, a nozzle 42 B, and a tailcone 46 , which are generally disposed about and/or rotate about an engine centerline 48 . In other embodiments, there may be, for example, an intermediate pressure spool having an intermediate pressure turbine.
[0014] In the depicted embodiment, engine 20 core flow is discharged through nozzle 42 A, and the bypass flow is discharged through nozzle 42 B. In other embodiments, other nozzle arrangements may be employed, e.g., a common nozzle for core and bypass flow; a nozzle for core flow, but no nozzle for bypass flow; or another nozzle arrangement. Bypass duct 30 and compressor 32 are in fluid communication with fan 28 . Nozzle 42 B is in fluid communication with bypass duct 30 . Diffuser 34 is in fluid communication with compressor 32 . Combustor 36 is fluidly disposed between compressor 32 and turbine 38 . Turbine 40 is fluidly disposed between turbine 38 and nozzle 42 A. In one form, combustor 36 includes a combustion liner 50 that contains a continuous combustion process. In other embodiments, combustor 36 may take other forms, and may be, for example, a wave rotor combustion system, a rotary valve combustion system, a pulse detonation combustion system or a slinger combustion system, and may employ deflagration and/or detonation combustion processes.
[0015] Fan system 28 includes a fan rotor system 48 driven by LP spool 26 . In various embodiments, fan rotor system 48 includes one or more rotors (not shown) that are powered by turbine 40 . Fan 28 may include one or more vanes (not shown). Bypass duct 30 is operative to transmit a bypass flow generated by fan 28 around the core of engine 20 . Compressor 32 includes a compressor rotor system 50 . In various embodiments, compressor rotor system 50 includes one or more rotors (not shown) that are powered by turbine 38 . Turbine 38 includes a turbine rotor system 52 . In various embodiments, turbine rotor system 52 includes one or more rotors (not shown) operative to drive compressor rotor system 50 . Turbine rotor system 52 is drivingly coupled to compressor rotor system 50 via a shafting system 54 . Turbine 40 includes a turbine rotor system 56 . In various embodiments, turbine rotor system 56 includes one or more rotors (not shown) operative to drive fan rotor system 48 . Turbine rotor system 56 is drivingly coupled to fan rotor system 48 via a shafting system 58 . In various embodiments, shafting systems 54 and 58 include a plurality of shafts that may rotate at the same or different speeds and directions. In some embodiments, only a single shaft may be employed in one or both of shafting systems 54 and 58 . Turbine 40 is operative to discharge the engine 20 core flow to nozzle 42 A.
[0016] During normal operation of gas turbine engine 20 , air is drawn into the inlet of fan 28 and pressurized by fan rotor 48 . Some of the air pressurized by fan rotor 48 is directed into compressor 32 as core flow, and some of the pressurized air is directed into bypass duct 30 as bypass flow. Compressor 32 further pressurizes the portion of the air received therein from fan 28 , which is then discharged into diffuser 34 . Diffuser 34 reduces the velocity of the pressurized air, and directs the diffused core airflow into combustor 36 . Fuel is mixed with the pressurized air in combustor 36 , which is then combusted. The hot gases exiting combustor 36 are directed into turbines 38 and 40 , which extract energy in the form of mechanical shaft power to drive compressor 32 and fan 28 via respective shafting systems 54 and 58 . The hot gases exiting turbine 40 are discharged through nozzle system 42 A, and provide a component of the thrust output by engine 20 .
[0017] Referring to FIG. 2 , some aspects of a non-limiting example of combustion liner 60 in accordance with an embodiment of the present invention is schematically depicted. Also illustrated are a fuel injector 62 and a swirler 64 employed to create a combustion process within combustion liner 60 . In one form, combustion liner 60 is an annular combustion liner, and includes an outer combustion liner 66 disposed radially around an inner combustion liner 68 . Outer combustion liner 66 terminates at an aft end 66 E. Inner combustion liner 68 terminates at an aft end 68 E. In other embodiments, combustion liner 60 may take other forms. In various embodiments, outer combustion liner 66 and/or inner combustion liner 68 in various locations are formed of one of three types of liner wall structure: a thermally cooled wall section; an acoustically damped wall section; and a thermally cooled and acoustically damped wall section. The type of liner wall structure varies with location along outer combustion liner 66 and/or inner combustion liner 68 in accordance with the need at each location on outer combustion liner 66 and/or inner combustion liner 68 for cooling and for acoustic damping of vibrations arising from the combustion process that is contained within combustion liner 60 during the operation of engine 20 . Thus, some portions of outer combustion liner 66 and inner combustion liner 68 employ a thermally cooled wall section, whereas other portions employ an acoustically damped wall section, and still other portions employ a thermally cooled and acoustically damped wall section. The type of wall section employed may vary along the length of outer combustion liner 66 and inner combustion liner 68 , e.g., in an alternating or other arrangement as between two or three different types of liner wall structure. In some embodiments, only one or two of the aforementioned three types of liner wall structure may be employed, whereas in other embodiments, all three types may be employed. The location along outer combustion liner 66 and inner combustion liner 68 of a particular type of liner wall structure in various embodiments may vary with the needs of the particular application, e.g., depending upon combustion liner temperatures and acoustic characteristics. The locations of the different types of liner wall structures shown in FIG. 2 by virtue of section lines 3 , 4 and 5 , from which the cross-sectional schematic illustrations of FIGS. 3-5 are for illustrative purposes only, and are not intended to limit the location of such liner wall structures in any manner.
[0018] Referring to FIG. 3 in conjunction with FIG. 2 , some aspects of a non-limiting example of a thermally cooled wall section 70 in accordance with an embodiment of the present invention are depicted. As illustrated in FIG. 2 , thermally cooled wall section 70 may be employed at one or more various locations on outer combustion liner 66 and inner combustion liner 68 . Thermally cooled wall section 70 includes an outer combustion liner wall (outer wall) 72 , an inner combustion liner wall (inner wall) 74 , and a cellular structure in the form of a porous open cell foam 76 . In various embodiments, one or more of outer wall 72 , inner wall 74 and open cell foam 76 may also be common with other liner wall structures, e.g., acoustically damped wall section 90 (discussed below with respect to FIG. 4 ) and thermally cooled and acoustically damped wall section 100 (discussed below with respect to FIG. 5 ). Open cell foam 76 is disposed between outer wall 72 and inner wall 74 . Outer wall 72 is exposed to diffused compressor discharge air flowing inside combustor 36 , whereas inner wall 74 is exposed to the heat of combustion from the combustion process 78 taking place inside combustion liner 60 during the operation of engine 20 . In one form, outer wall 72 is a structural wall configured to support the balance of the combustion liner 60 , e.g., open cell foam 76 and inner wall 74 of thermally cooled wall section 70 .
[0019] In one form, outer wall 72 , inner wall 74 and open cell foam 76 are formed of a ceramic matrix composite. In other embodiments, one or more of outer wall 72 , inner wall 74 and open cell foam 76 may be formed of one or more other composite, metallic and/or intermetallic materials or other materials. In one form, outer wall 72 , inner wall 74 and open cell foam 76 are formed integrally as a unit, i.e., a unitary structure, e.g., wherein outer wall 72 , inner wall 74 and open cell foam 76 are formed separately and then affixed together, e.g., via bonding or another material joining process to yield a one-piece unitary structure as the end product. In other embodiments, outer wall 72 , inner wall 74 and open cell foam 76 may be formed as a unitary structure by use of a stereolithography process or another freeform or similar such manufacturing process. In still other embodiments, outer wall 72 , inner wall 74 and open cell foam 76 may not be formed as a unitary structure, i.e., outer wall 72 , inner wall 74 and open cell foam 76 may be assembled using mechanical fasteners, interference fits and/or other deformation schemes or the like.
[0020] In one form, outer wall 72 includes a plurality of cooling air supply openings 80 configured to receive cooling air 82 from outside of outer wall 72 . In other embodiments, outer wall may not include cooling air supply openings. In still other embodiments, cooling air may be supplied via other means, e.g., from an end of outer wall 72 adjacent to swirler 64 . Open cell foam 76 is configured to distribute cooling air received from cooling air supply openings 80 . In one form, open cell foam 76 is configured to distribute cooling air 82 along inner wall 74 for convective cooling of inner wall 74 . In other embodiments, open cell foam 76 may not be so configured. In one form, open cell foam 76 is configured to conduct heat away from inner wall 74 and transmit the heat to cooling air 82 . In other embodiments, open cell foam 76 may not be so configured. In one form, in thermally cooled wall section 70 , inner wall 74 includes a plurality of openings 84 . In one form, openings 84 are in fluid communication with open cell foam 76 . In one form, open cell foam 76 is configured to distribute cooling air 82 to openings 84 . Openings 84 are configured to discharge cooling air 82 , e.g., for film cooling of inner wall 74 .
[0021] Referring to FIG. 4 in conjunction with FIG. 2 , some aspects of a non-limiting example of an acoustically damped wall section 90 in accordance with an embodiment of the present invention are depicted. As illustrated in FIG. 2 , acoustically damped wall section 90 may be employed at one or more various locations on outer combustion liner 66 and inner combustion liner 68 . Acoustically damped wall section 90 includes an outer wall, e.g., outer wall 72 , an inner wall, e.g., inner wall 74 , and a cellular structure in the form of an honeycomb 92 . In various embodiments, one or more of outer wall 72 , inner wall 74 and honeycomb 92 may also be common with other liner wall structures, e.g., thermally cooled and acoustically damped wall section 100 (discussed below with respect to FIG. 5 ). Honeycomb 92 is disposed between outer wall 72 and inner wall 74 . As with thermally cooled wall section 70 , outer wall 72 is exposed to diffused compressor discharge air flowing inside combustor 36 , whereas inner wall 74 is exposed to the heat of combustion from combustion process 78 taking place inside combustion liner 60 during the operation of engine 20 . In one form, outer wall 72 is a structural wall configured to support the balance of the combustion liner 60 , e.g., honeycomb 92 and inner wall 74 of acoustically damped wall section 90 .
[0022] In one form, outer wall 72 , inner wall 74 and honeycomb 92 are formed of a ceramic matrix composite. In other embodiments, one or more of outer wall 72 , inner wall 74 and honeycomb 92 may be formed of one or more other composite, metallic and/or intermetallic materials. In one form, outer wall 72 , inner wall 74 and honeycomb 92 are formed integrally as a unit, i.e., a unitary structure, e.g., wherein outer wall 72 , inner wall 74 and honeycomb 92 may be formed separately and then affixed together, e.g., via bonding or another material joining process to yield a unitary structure as the end product. In other embodiments, outer wall 72 , inner wall 74 and honeycomb 92 may be formed as a unitary structure by use of a stereolithography process or another freeform or similar such manufacturing process. In still other embodiments, outer wall 72 , inner wall 74 and honeycomb 92 may not be formed as a unitary structure, i.e., outer wall 72 , inner wall 74 and honeycomb 92 may be assembled using mechanical fasteners, interference fits and/or other deformation schemes or the like. In one form, outer wall 72 and inner wall 74 are continuous as between thermally cooled wall section 70 and acoustically damped wall section 90 , i.e., extending continuously between sections 70 and 90 . In other embodiments, outer wall 72 and inner wall 74 may be discontinuous as between thermally cooled wall section 70 and acoustically damped wall section 90 . In one form, outer wall 72 and inner wall 74 have a same wall thickness in both thermally cooled wall section 70 and acoustically damped wall section 90 . In other embodiments, outer wall 72 and inner wall 74 may have different thicknesses as between sections 70 and 90 .
[0023] Honeycomb 92 includes a plurality of cells 94 . In acoustically damped wall section 90 , inner wall 74 includes a plurality of openings 96 . In one form, each cell 94 is exposed to an opening 96 . In other embodiments, each cell 94 may be exposed to more than one opening 96 . Cells 94 and openings 96 are configured to acoustically damp vibrations at one or more selected frequencies, e.g., at frequencies associated with the geometry of combustion liner 60 and combustion process 78 and/or other parameters that yield undesirable noise emanating from engine 20 and/or are potentially damaging to one or more engine 20 components. The desired frequencies may be selected by various means, e.g., including component and/or engine testing, vibration analysis, computational fluid dynamics analysis and/or other empirical and/or analytical methods. Various parameters may be controlled in order to achieve a desired acoustic damping, including the size and volume of cells 94 , the size of openings 96 , the thickness of inner wall 74 , as well as other parameters, e.g., the selection of material properties of one or more of outer wall 72 , inner wall 74 and honeycomb 92 .
[0024] In one form, the acoustical damping is effected when a high pressure wave passes through openings 96 , whereby cells 94 absorb at least a portion of the high pressure wave. In some embodiments, the wave energy may be at least partially viscously damped as the wave passes through openings 96 . Then, during a lull in pressure inside combustion liner 60 as the high pressure wave recedes, cells 94 release the higher pressure stored therein, adding the pressure to the trough of the receding wave. Also, in some embodiments, additional viscous damping may be achieved as the dynamic mass flow exits cells 94 via openings 96 .
[0025] Referring to FIG. 5 , a thermally cooled and acoustically damped wall section 100 is depicted. As illustrated in FIG. 2 , thermally cooled and acoustically damped wall section 100 may be employed at one or more various locations on outer combustion liner 66 and inner combustion liner 68 . Thermally cooled and acoustically damped wall section 100 includes an outer wall, e.g., outer wall 72 , an inner wall, e.g., inner wall 74 , a layer of a cellular structure in the form of open cell foam 76 , an intermediate wall 102 , and a layer of a cellular structure in the form of honeycomb 92 . Open cell foam 76 and honeycomb 92 are disposed between outer wall 72 and inner wall 74 . In particular, in acoustically damped wall section 100 , open cell foam 76 is disposed between outer wail 72 and intermediate wall 102 ; and honeycomb 92 is disposed between intermediate wall 102 and inner wall 74 .
[0026] As with thermally cooled wall section 70 and acoustically damped wall section 90 , outer wall 72 is exposed to diffused compressor discharge air flowing inside combustor 36 , whereas inner wall 74 is exposed to the heat of combustion from combustion process 78 taking place inside combustion liner 60 during the operation of engine 20 . In one form, outer wall 72 is a structural wall configured to support the balance of the combustion liner 60 , e.g., open cell foam 76 , intermediate wall 102 , honeycomb 92 and inner wall 74 of thermally cooled and acoustically damped wall section 100 .
[0027] In one form, outer wall 72 , open cell foam 76 , intermediate wall 102 , honeycomb 92 and inner wall 74 are formed of a ceramic matrix composite. In other embodiments, one or more of outer wall 72 , open cell foam 76 , intermediate wall 102 , honeycomb 92 and inner wall 74 may be formed of one or more other composite, metallic and/or intermetallic materials. In one form, outer wall 72 , open cell foam 76 , intermediate wall 102 , honeycomb 92 and inner wall 74 are formed integrally as a unit, i.e., a unitary structure, e.g., wherein outer wall 72 , open cell foam 76 , intermediate wall 102 , honeycomb 92 and inner wall 74 are formed separately and then affixed together, e.g., via bonding or another material joining process to yield a unitary structure as the end product. In other embodiments, outer wall 72 , open cell foam 76 , intermediate wall 102 , honeycomb 92 and inner wall 74 may be formed integrally as a unitary structure by use of a stereolithography process or another freeform or similar such manufacturing process. In still other embodiments, outer wall 72 , open cell foam 76 , intermediate wall 102 , honeycomb 92 and inner wall 74 may not be formed as a unitary structure, i.e., outer wall 72 , open cell foam 76 , intermediate wall 102 , honeycomb 92 and inner wall 74 may be assembled using mechanical fasteners, interference fits and/or other deformation schemes or the like.
[0028] In one form, outer wall 72 and inner wall 74 are continuous as between thermally cooled wall section 70 , acoustically damped wall section 90 and thermally cooled and acoustically damped wall section 100 , i.e., extending continuously between sections 70 , 90 and 100 . In other embodiments, outer wall 72 and inner wall 74 may be discontinuous as between thermally cooled wall section 70 , acoustically damped wall section 90 and thermally cooled and acoustically damped wall section 100 . In one form, outer wall 72 and inner wall 74 have a same wall thickness in thermally cooled wall section 70 , acoustically damped wall section 90 and thermally cooled and acoustically damped wall section 100 . In other embodiments, outer wall 72 and inner wall 74 may have different thicknesses as between sections 70 , 90 and 100 .
[0029] In one form, in thermally cooled and acoustically damped wall section 100 , outer wall 72 includes a plurality of cooling air supply openings 80 configured to receive cooling air 82 from outside of outer wall 72 . In other embodiments, outer wall 72 may not include cooling air supply openings 80 . The size of openings 80 may vary with location in thermally cooled and acoustically damped wall section 100 , and may vary as with respect to the size of openings 80 in thermally cooled wall section 70 . In still other embodiments, cooling air 82 may be supplied via other means, e.g., from an end of outer wall 72 adjacent to swirler 64 . As with thermally cooled wall section 70 , open cell foam 76 is configured to distribute cooling air received from cooling air supply openings 80 . In one form, open cell foam 76 is configured to distribute cooling air 82 along intermediate wall 102 for convective cooling of intermediate wall 102 . In other embodiments, open cell foam 76 may not be so configured. In one form, open cell foam 76 is configured to conduct heat away from intermediate wall 102 and transmit the heat to cooling air 82 . In other embodiments, open cell foam 76 may not be so configured. Cooling air 82 may be discharged from open cell foam 76 at one or more locations, e.g., openings (not shown) in intermediate wall 102 and/or openings (not shown) in ends 66 E and 68 E.
[0030] As with acoustically damped wall section 90 , honeycomb 92 includes a plurality of cells 94 , and inner wall 74 includes a plurality of openings 96 . Cells 94 are defined by walls 98 . In one form, each cell 94 is exposed to an opening 96 . In other embodiments, each cell 94 may be exposed to more than one opening 96 . Cells 94 and openings 96 are configured to acoustically damp vibrations at one or more selected frequencies, e.g., at frequencies associated with the geometry of combustion liner 60 and combustion process 78 and/or other parameters that yield undesirable noise emanating from engine 20 and/or are potentially damaging to one or more engine 20 components. Various parameters may be controlled in order to achieve a desired acoustic damping, including the size, shape and volume of cells 94 , the size of openings 96 , the thickness of inner wall 74 , as well as other parameters, e.g., the selection of material properties of one or more of outer wall 72 , open cell foam 76 , intermediate wall 102 , honeycomb 92 and inner wall 74 . The size volume of cells 94 , and the size and shape of openings 96 in thermally cooled and acoustically damped wall section 100 may vary as with respect to cells 94 and openings 96 in acoustically damped wall section 90 . The acoustical damping may be obtained in thermally cooled and acoustically damped wall section 100 in the same manner as acoustically damped wall section 90 .
[0031] Embodiments of the present invention include a combustion liner, comprising: an outer combustion liner wall; an inner combustion liner wall; and a cellular structure disposed between the outer combustion liner wall and the inner combustion liner wall, wherein at least one of the outer combustion liner wall and the inner combustion liner wall includes a plurality of openings extending therethrough.
[0032] In a refinement, the cellular structure is formed of a composite material.
[0033] In another refinement, the composite material is a ceramic matrix composite.
[0034] In yet another refinement, the outer combustion liner wall, the inner combustion liner wall and the cellular structure are formed of one or more composite materials.
[0035] In still another refinement, the one or more composite materials includes a ceramic matrix composite.
[0036] In yet still another refinement, the outer combustion liner wall, the inner combustion liner wall and the cellular structure are formed as a unitary structure.
[0037] In a further refinement, the inner combustion liner wall includes the plurality of openings; wherein the cellular structure is a honeycomb formed of a plurality of cells exposed to the plurality of openings; and wherein the plurality of cells and the plurality of openings are configured to acoustically damp vibrations at one or more selected frequencies.
[0038] In a yet further refinement, the outer combustion liner wall includes the plurality of openings in the form of cooling air supply openings; and wherein the cellular structure is an open cell foam configured to distribute cooling air received from the cooling air supply openings.
[0039] In a still further refinement, the inner combustion liner wall includes an other plurality of openings configured to discharge cooling air received from the open cell foam.
[0040] In a yet still further refinement, the cellular structure varies in nature as between different locations about the combustion liner; wherein the cellular structure is in the form of an open cell foam configured to distribute cooling air at one or more locations on the combustion liner; and wherein the cellular structure forms at least part of an acoustic damper configured to acoustically damp vibrations at one or more selected frequencies at another one or more locations on the combustion liner.
[0041] In an additional refinement, the acoustic damper includes the cellular structure in the form of a honeycomb.
[0042] In another additional refinement, the cellular structure includes a layer of open cell foam and a layer of the at least part of the acoustic damper at a same location of the combustion liner.
[0043] In yet another additional refinement, the combustion liner further comprises an intermediate wall disposed between the honeycomb and the open cell foam.
[0044] Embodiments of the present invention include a combustion liner, comprising: an outer combustion liner wall having a cooling air supply opening therein; a porous open cell foam positioned disposed in fluid communication with the cooling air supply opening; and an inner combustion liner wall, wherein the open cell foam is configured to distribute cooling air received from the cooling air supply openings.
[0045] In a refinement, the inner combustion liner wall includes a plurality of openings configured to discharge cooling air received from the open cell foam.
[0046] In another refinement, the inner combustion liner wall includes a plurality of openings; further comprising a honeycomb disposed between the inner combustion liner wall and the outer combustion liner wall; wherein the honeycomb includes a plurality of cells in fluid communication with the plurality of openings; wherein the plurality of cells and the plurality of openings are configured to acoustically damp vibrations at one or more selected frequencies in the combustion liner.
[0047] In yet another refinement, the combustion liner further comprises an intermediate wall disposed between the open cell foam and the honeycomb.
[0048] In still another refinement, the outer combustion liner wall, the open cell foam, the honeycomb and the inner combustion liner wall are formed integrally as a unit.
[0049] In yet still another refinement, the outer combustion liner wall, the open cell foam and the inner combustion liner wall are formed integrally as a unit.
[0050] In a further refinement, the outer combustion liner wall is a structural wall configured to support the balance of the combustion liner.
[0051] Embodiments of the present invention include a gas turbine engine, comprising: a compressor; a combustor in fluid communication with the compressor; and a turbine in fluid communication with the combustor, wherein the combustor includes a combustion liner includes an outer combustion liner wall; an inner combustion liner wall; means for cooling the combustion liner disposed between the outer combustion liner wall and the inner combustion liner wall; and means for acoustically damping vibrations disposed between the outer combustion liner wall and the inner combustion liner wall.
[0052] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary. | One embodiment of the present invention is a unique gas turbine engine combustion liner. Another embodiment is a unique gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and gas turbine engine combustion liners. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith. | 5 |
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62/063,858, filed Oct. 14, 2014, which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The field of the invention is fabric and fiber dyeing.
BACKGROUND
[0003] Traditionally, application of dyes to fibers is performed by contacting a mass of fiber, yarn, thread, or similar filamentous materials with a solution of a dye or colorant. This is generally performed at elevated temperatures, with the dye in an aqueous solution. In this process the amount of dye that is utilized is far in excess of the capacity of the yarn or thread, so following application and fixing the excess dye is removed, generally by extensive washing or rinsing in water. This process is inefficient and wasteful in terms of expensive dyestuffs and in terms of fresh water (which is in increasingly short supply).
[0004] In conventional processes, dying fiber typically requires the performance of multiple color test cycles in order to optimize mixing, application, and cleaning before the final produced color of the dyed fiber can be approved. Once proper conditions are determined large quantities of colorant, chemicals and water are transferred to a dye vessel. This dye vessel must be carefully cleaned of previous colorants and chemicals prior to use in order to prevent contamination. Such pre-process and post-process steps consume significant time, during which dyeing operations. As a result dye houses are forced to compensate for this lost time by requiring a certain minimum volume for production runs of dyed fibers and typically need to charge significant premiums for short runs.
[0005] Once dyed, the fiber, yarn, thread or other filamentous material is typically wound on a reel or spool. These spools or reels are stored until they are needed, then supplied to knitting machines or similar devices to be incorporated into clothing and other textiles. This process is similarly wasteful, due to shipping of the dyed materials from the dyeing facility to the linen fabrication facility (thereby generating greenhouse gases), utilization of large amounts of space for storage, inevitable losses during storage, incurring significant labor costs to supply and resupply the reels or spools as they are needed, and the need to use elaborate inventory control and monitoring systems to track the supply and usage of each type of dyed material.
[0006] Thus, there is still a need for rapid and efficient systems and methods for dyeing filamentous materials with minimal environmental impact, and that can do so on an on-demand basis that is relatively independent of run volume.
SUMMARY OF THE INVENTION
[0007] Embodiments of the inventive concept include systems, methods, and devices that dispense microdroplets of dye onto individual filaments or fibers and infuse them into the interior of such filaments and/or fibers in a highly controlled manner. Control of dye dispensing permits changing the dye applied to a fiber during a dyeing operation, and supports the generation of patterns in woven products via the dyeing process.
[0008] One embodiment of the inventive concept is a system for producing a colored filament that includes a source of a filament (which can include a polymer, a colorant application unit that receives the filament and includes a print head, wherein the print head that is in fluid communication with a dye or colorant, a colorant infusion unit that receives a coated filament from the colorant application unit and includes a source of infrared radiation and is in connected to one or more vacuum source (which reduces the pressure within the colorant application unit to less than ambient air pressure) and a drive unit that moves the filament through the colorant infusion unit and the colorant infusion unit. In some embodiment the print head is in fluid communication with a second dye or colorant, and the print head can be instructed to dispense a first colorant a second colorant over different time intervals. Suitable colorants or dyes include disperse dyes or reactive dyes. In some embodiments the polymer of the filament includes a crystalline phase, and amorphous phase, and an intermediate phase interposed between the crystalline phase and the amorphous phase. The source of infrared radiation emits a wavelength of infrared radiation at an energy that corresponds to a boson peak in the infrared energy absorbance profile of the polymer. The system of one claim 1 wherein the primary colorant is a disperse dye. After dyeing, the fiber can be collected on a take up reel or can be supplied directly to a fabrication unit (such as a knitting machine). In some embodiments a preheating module is placed between the colorant application unit and the colorant infusion unit.
[0009] Another embodiment of the inventive concept is a system in which two or more systems as described above are arranged to work in parallel, such that two or more filaments or fibers are dyed simultaneously. In such embodiments the colorant infusion units can be connected to one or more common vacuum sources (for example, using a manifold). In such embodiments two or more of the dyed filaments or fibers produced can be supplied to a single reel or to a single fabrication device (for example, a knitting machine).
[0010] Yet another embodiment of the inventive concept is a method of providing a colored filament comprising in which a filament is moved through a colorant application unit and a colorant infusion unit. A a primary colorant is dispensed onto a first portion of the filament as it is moves through a colorant application unit by a print head to generate a first segment of a coated filament. This is transferred to the colorant infusion unit where a first infrared irradiation is applied to the coated filament at a pressure below that of ambient air pressure. This disperses the primary colorant within the coated filament to generate a first segment of a colored filament. In some embodiments a secondary colorant is dispensed onto a second segment of the filament as it moves through the colorant application unit by the same print head to generate a second segment of the coated filament, and a second infrared irradiation is applied to the coated filament at a pressure below that of ambient air pressure as it moves through the colorant infusion unit. This disperses the secondary colorant within the coated filament to generate a second segment of the colored filament. In preferred embodiments the gap between the first segment of colored filament and the second segment of colored filament is equal to or less than 2 cm. Suitable dyes include disperse dyes and reactive dyes, and in some embodiments the primary colorant is a disperse dye and the secondary colorant is a reactive dye. Following infusion of the colorant, the filament can be transferred to either a take up reel or a fabricator
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 schematically depicts an embodiment of a system of the inventive concept, in which multiple fibers are dyed simultaneously.
DETAILED DESCRIPTION
[0012] The inventive subject matter provides apparatus, systems and methods in which a one or more filaments (i.e. thread, yarn, fiber, ribbon, or similar materials that can be woven to form a fabric, web, and/or mesh) have colorant dispensed on their surface in the form of microdroplets, which dry rapidly to form a colorant-coated filament. The dispensed colorant can be changed during processing, permitting more than one colorant to be added to a given filament. The colorant-coated filament moves to a colorant infusion unit, in which the colorant is drawn into the fiber. In a preferred embodiment the colorant infusion unit applies infrared radiation at reduced pressure, thereby permitting the colorant to move to the interior of the filament. The colored filament can be collected on a take up reel or can be supplied directly to a knitting machine or similar device without the need for a rinsing or washing step, resulting in a drastic reduction in water consumption and elimination of the need for shipping from a dyeing facility. In preferred systems, two or more sets of colorant application units and colorant infusion units work to process a corresponding number of filaments in parallel.
[0013] The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0014] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0015] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0016] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0017] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.
[0018] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
[0019] One should appreciate that the disclosed techniques provide many advantageous technical effects including a dramatic reduction in the consumption of fresh water and in the production of greenhouse gases generated by shipping operations. Similarly, storage and inventory control are simplified.
[0020] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.
[0021] In embodiments of the inventive concept the filament to which the colorant is applied can be a thread, yarn, twine, ribbon, or other substantially linear and flexible component that can be woven into a fabric, mesh, or web. Such a filament can have a polymeric composition. Suitable polymers include naturally occurring polymers (for example, cellulose or silk), synthetic polymers (for example, polypropylene, polyester, or polyamide), and/or a combination of these. In some embodiments the filament is composed of two or more sub-filaments or strands that are coupled to one another, for example by winding the sub-filaments around one another, so that they move and are processed as a single filament.
[0022] Embodiments of the inventive concept include a device for processing of a single fiber. Other embodiments of the inventive concept include systems that include two or more of such devices operating in parallel. As such, descriptions of the various components and operations below are applicable to the features and operation of both device and system embodiments of the inventive concept.
[0023] FIG. 1 provides a schematic representation that depicts a system 100 that processes seven of such filaments simultaneously. Descriptions directed to a single filament are understood to be potentially applicable to all filaments being processed within such a system, in concert or independently, unless stated otherwise. A filament is supplied by a source 110 . Such a source can be a reel, spool, hank, or similar arrangement or reservoir capable of supplying the filament in an untangled manner. In some embodiments of the inventive concept the source can be a mechanism that produces the filament from a raw material as needed, for example a mechanism that receives cotton, spins the cotton into strands, and winds the strands into a cotton thread that is supplied to the system as a filament.
[0024] From the source the filament moves through a colorant application unit 120 . The colorant application unit dispenses numerous small-volume (i.e. 0.1 to 100 pL) microdroplets of colorant onto the filament as it moves through to produce a coated filament. In a preferred embodiment of the inventive concept the volume of a colorant microdroplet is 1 to 1.5 pL. At these volumes the colorant is dry before the coated filament (or the coated portion of the filament) leaves the colorant application unit. The colorant can be dispensed by any suitable means, but is preferably dispensed using a MEMS print head that is in fluid communication with one or more sources of colorant. Such devices provide accurate and reproducible dispensing of suitably small volumes, and provide an area over which the colorant can be dispensed that is substantially larger than that of other microdispensing methods (for example, micropipettors and conventional ink jets). Such a large dispensing area supports rapid processing speeds. In preferred embodiments of the inventive concept a filament can move through a colorant application unit at a rate greater than or equal to 100 meters per minute.
[0025] In a system such as shown in FIG. 1 , a colorant application unit 120 or a set of colorant application units can be controlled using a digital color controller 130 . The digital color controller can be used to instruct a colorant application unit to change the colorant that is applied to a filament as it moves through the colorant application unit. This can be accomplished by changing the source of colorant that is supplied to a print head. Alternatively, this can be accomplished by switching from a first set of dispensing nozzles of a print head that are dispensing a first colorant to a second set of dispensing nozzles of the print head that are dispensing a second, different colorant. In a preferred embodiment of the inventive concept a colorant application unit can change the colorant that is dispensed to a filament while leaving a gap of about 10, 8, 6, 4, 2, or less than 2 cm between the portions of the filament over which the first colorant and the second colorant are dispensed. In some embodiments of the inventive concept print head (or similar device) of a colorant application unit can dispense two or more colorants to the same region of the filament, producing a blended result. In still other embodiments of the inventive concept, the digital color controller can instruct the colorant application unit to dispense different amounts of the same colorant to the filament, thereby varying the intensity of shading along the length of the filament. This can be achieved, for example, by adjusting the rate at which the microdroplets of dye are dispensed and/or adjusting the volume of the dispensed microdroplets.
[0026] It should be appreciated that the use of such a colorant application unit dramatically reduces the amount and the volume of colorant that is applied to a filament relative to conventional dyeing processes. Additional features can reduce this even further. For example, the MEMS print head can be controlled such that only nozzles that are in contact with or in immediate proximity (i.e. less than 1 cm) to the filament are activated to dispense colorant. In some embodiments the colorant application unit can impart a charge to the filament and an opposing charge to the dispensed colorant, so that the dispensed droplets of colorant are impelled onto the filament. In such an embodiment interior walls of the colorant application unit can carry a charge that matches that of the dispensed colorant droplet, repelling the colorant from the walls of the colorant application unit and reducing the need for cleaning and other maintenance. Colorant application units can be provided with filter, forced air, and/or vacuum resources that serve to remove or segregate colorant that failed to adhere to the filament on colorant dispensing.
[0027] Colorants of the inventive concept can be any material, either liquid or in liquid suspension, that the user wishes to incorporate into or bond to the filament. For example, a colorant can be a disperse dye or suspension of disperse dye in a suitable solvent. Alternatively, a colorant can be a reactive dye. It should be appreciated, however, that systems and methods of the inventive concept can also be used to incorporate other functional molecules into a filament, for example UV protectors, conductive materials (i.e. metals, graphites, fullerenes, nanotubes, and other carbon clusters), water repellants, insect repellants and/or insecticides, and pharmaceuticals (for example antiseptics, antibiotics, anticoagulants, tissue growth and/or trophic factors, etc.).
[0028] As shown in FIG. 1 , on exiting the colorant application unit 120 the coated filament is directed to a colorant infusion unit 150 . In doing so the coated filament can be passed through a preheating unit 140 , for example a set of heated rollers. Such heated rollers can also form part of an impelling mechanism that moves the filament through the system. A colorant infusion unit of the inventive concept includes one or more sources of infrared radiation. Such a source can be a source of electromagnetic radiation (EM radiation) that provides electromagnetic energy in the wavelength range of 700 nm to 1 mm. Alternatively, such a source can be a resistive heater. In a preferred embodiment of the inventive concept the colorant infusion unit includes both EM radiation sources and resistive heaters. In some embodiments of the inventive concept the EM radiation source can provide two or more wavelengths, for example by energizing different sets of EM radiation emitters (for example LED or laser sources) or by the use of a wavelength selector (for example, a diffraction grating or interferometer).
[0029] A colorant infusion unit of the inventive concept is operated at reduced (i.e. below ambient air pressure). Towards that end such a colorant infusion unit is in communication with one or more vacuum units 160 that serve to exhaust air from the colorant infusion unit. The inventor has found, surprisingly, that reducing the pressure surrounding a coated filament greatly reduces the energy (in the form of infrared energy, heat, or a combination thereof) necessary to incorporate or draw the colorant into the filament. In preferred embodiments of the inventive concept the pressure within such reduced pressure portions of the system or device is about 759, 700, 600, 500, 400, 300, 200, 100, 30, 10, 3, 1, 0.3, 0.1, or less than about 0.1 Torr. In order to efficiently maintain a low pressure environment within the colorant infusion unit as the filament moves through, the filament can pass through an area or stage that is evacuated using a pump that is capable of moving large quantities of air but does not maintain a high vacuum (for example, a rotary pump) and then through a second area or stage that is evacuated using a pump that is capable of maintaining a high vacuum but that does not move large volumes of air (for example, a cam or a piston pump). The two vacuum stage sections can be separated by a sealing device (for example, a pair of silicone rollers) that reduce air loss between the vacuum stages as the filament moves through the sealing device. A similar set of vacuum stages can be supplied at the exit of the colorant infusion unit. In some embodiments of the inventive concept, the rollers of such a sealing device can form part of an impelling mechanism that moves the filament through the system.
[0030] Inside of the colorant infusion unit the coated filament is subjected to EM radiation, temperature, and vacuum conditions that either draw the dye into the interior of the fiber (in the case of disperse dyes) are permit the dye to chemically react with the filament (in the case of reactive dyes). Such conditions can be selected so that the energy (in the form of EM radiation and/or heat) lies within a boson peak characteristic of the energy absorption of a polymer of the filament. For example, polymeric filaments can have heterogeneous structures that include a highly crystalline phase in the form of inclusions within a less organized and relatively amorphous phase. An intermediate region lies between these phases. As energy (in the form of EM radiation and/or heat) is added to such materials a boson peak, or deviation from linearity, is often observed in a graph of energy added to the material versus the degrees of freedom available to molecular species of the material. The inventor has found that such a boson peak coincides with the development of tunnels or channels within the polymeric filament (generally at least partially within the intermediate regions), at least some of which extend to the exterior of the filament and can permit a colorant coating to enter the interior of the filament. The inventor has also found that application of a vacuum to such materials reduces the amount of energy that needs to be applied to reach such a boson peak, bringing it into a range that is compatible with colorant materials and polymers commonly used in filament production. A subsequent reduction in the energy applied to the filament results in the collapse of the tunnels or channels, which serves to trap the colorant within the filament and disperse it throughout the interior of the filament. In a preferred embodiment of the inventive concept, the colorant is selected to be fluidly mobile at EM radiation and temperature conditions corresponding to a boson peak of a polymer of the filament. It should be appreciated that a colorant infusion unit of the inventive concept can be controlled to provide such conditions for a wide variety of polymeric materials. In a preferred embodiment of the inventive concept, the filament, the colorant, the dispensed amount of colorant, and the conditions within the colorant infusion unit are selected so that essentially all (i.e. >90%) of the colorant applied to the filament migrates to the interior of the filament. This advantageously minimizes or, preferably, eliminates the need to wash or rinse the filament following colorant infusion.
[0031] Similarly, a colorant infusion unit can be controlled to provide EM radiation, temperature, and vacuum conditions that permit reactive dyes to form chemical bonds with a polymer of a filament. In a preferred embodiment of the inventive concept, the filament, the colorant, the dispensed amount of colorant, and the conditions within the colorant infusion unit are selected so that essentially all (i.e. >90%) of the colorant applied to the filament migrates forms a chemical bond with a polymer of the filament. This advantageously minimizes or, preferably, eliminates the need to wash or rinse the filament following colorant infusion. In some embodiments, for example where a colorant application unit has switched from applying a disperse dye to applying a reactive dye to a given filament, a colorant infusion unit can change EM radiation, temperature, and/or vacuum conditions as a filament moves through it.
[0032] On exiting the colorant infusion unit, the colored filament can pass through a polishing unit 170 . Such a polishing unit can, for example, apply a wax, polish, or other similar coating that simplifies handling and/or processing of the colored filament in subsequent steps. In some embodiments of the inventive concept the final colored filament is transferred to a take up reel 180 , where it is stored prior to use. In some embodiments of the inventive concept the take up reel can form at least part of an impelling mechanism that serves to move the filament through the system. For example, tension supplied by a rotating take up reel can serve to draw the filament from the source and through the colorant application unit and the colorant infusion unit at a desired rate (for example, 100 meters per minute or faster). Alternatively, the final colored filament can be supplied directly to a fabrication unit, for example a knitting machine or a loom, that generates a fabric, mesh, web, or similar woven product. In such embodiments a feed mechanism of the fabrication unit can form at least part of an impelling mechanism that serves to move the filament through the system.
[0033] It should be appreciated that the digital color controller can configure the system to produce a multiple-dyed filament, such that the dyed segments of the filament form a desired pattern in the final fabric or mesh. Towards that end, a gap between such colored segments can serve to provide indicia to an automated knitting machine of an impending change in the colorant applied to the filament. In some embodiments of the inventive concept the digital color controller can be configured to supply indicia regarding the nature of the subsequent colorant within such a gap, for example by encoding such information using a UV-visible colorant not readily perceived by a consumer.
[0034] It should also be appreciated that systems and methods of the inventive concept provide far greater flexibility in regards to the amount of dyed filament that can be processed economically relative to systems and methods of the prior art. Since the process is essentially continuous (within the limits of the supplied filament and colorant), non-productive down time is greatly minimized and the relative costs of producing smaller quantities of dyed filament are proportionately reduced.
[0035] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc. | Systems, methods, and devices are described that dispense microdroplets of dye onto individual filaments or fibers and infuse them into the interior of such filaments and/or fibers in a highly controlled manner. Control of dye dispensing permits changing the dye applied to a fiber during a dyeing operation, and supports the generation of patterns in woven products via the dyeing process. The resulting systems and methods require much less water and generate much less waste than conventional dyeing processes. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to pre-filled syringes for administering various fluids into a patient, more particularly, the invention relates to plastic syringes for injecting liquid pharmaceutical/biological agents, such as diagnostic imaging agents into a patient.
2. Reported Development
Various syringes for taking body fluid samples or administering fluid medicaments to a patient are known. Such syringes generally include a cylindrical syringe barrel, a hypodermic needle engaged with the syringe barrel, and a plunger within the syringe barrel which, when a force is exerted axially by an operator, create a suction force drawing body fluids into the barrel, or delivers fluid medicament through the hypodermic needle. The purpose of the plunger is to provide an air tight seal between itself and the syringe barrel so that movement of the plunger up and down the barrel will allow liquid, blood or other fluids to be drawn into or forced out of the syringe through the distal end.
Syringes used for such purposes include glass syringes, in which the cylindrical barrel is made of glass and the plunger is a ground glass rod which closely fits within the cylindrical barrel. In order to eliminate leakage and at the same time reduce resistance to an acceptable level, close tolerances are necessary between the barrel and the plunger along with the use of a lubricant. These glass syringes suffer from a number of disadvantages including that: they are expensive since they require close tolerances; they cannot be easily mass produced since the plungers often cannot be interchanged with one another and have to be individually fit with the barrel during the grinding process by the manufacturer; and they are susceptible to breakage.
To obviate these problems syringes were proposed and/or made by using glass and plastic barrels with plastic or elastomeric plungers. In order to prevent leakage around the plunger, the plunger is made with one or more ribs which are slightly larger in diameter in the uncompressed state than the inside of the barrel which upon placement within the barrel are compressed and deformed against the wall of the barrel and thereby form a seal. The quality and strength of the seal depend on the elastomeric properties of the material used to make the plunger and the ratio of the respective diameters of the plunger and the inside of the barrel. To obtain a good leak-proof seal, a relatively large compressive force must be exerted on the elastomeric plunger by the syringe barrel. This quality of seal, however, makes the movement of the plunger within the barrel difficult requiring excessive force on the part of the operator to move the plunger. This drawback is even more pronounced with pre-filled syringes which are maintained, ready to use, in storage. During this shelf-life the plunger tends to bind with the barrel. To remedy the problem the prior art used lubricants to reduce friction and drag between the plunger and the inside of the syringe barrel. One of the commonly used lubricants for this purpose is silicone oil. The use of such lubricants is, however, undesirable, since the lubricants tend to disperse and/or dissolve in parenteral formulations thereby contaminating the formulations. Such potential adulteration is, of course, undesirable and attempts were made to avoid the use of lubricants and still provide a leakage-proof syringe with easily slideable plunger. Such attempts included the use of various plunger configurations including one or more ribs thereon projecting forwardly or rearwardly in the barrel to reduce the frictional drag between the plunger and the barrel. Another approach was, for example in U.S. Pat. No. 5,009,646, to laminate the elastomeric plunger with a film of tetrafluoroethylene, ethylenetetrafluoroethylene or ultrahigh molecular weight polyethylene resin.
While liquid tightness and sliding property have somewhat improved with these attempts as regards to syringes intended for taking body fluid samples or injecting medicaments from stored vials, the problem of inadequate sliding property in pre-filled syringes stored for extended time periods still remain unsolved.
It is a main object of the present invention to provide a pre-filled syringe and a pre-filled cartridge which will overcome the above-described inadequate sliding property while maintaining a tight, leak-proof seal between the plunger and the wall of the syringe barrel.
It is another object of the present invention to provide a self-aspirating syringe and cartridge.
In medical practice, hypodermic injections are sometimes administered subcutaneously, intramuscularly or intravenously, depending upon the particular medication to be administered. In all cases, it is essential that the practitioner know with certainty, prior to injection of the medication whether the hypodermic needle tip is located in a major blood vessel, such as a vein, or in subcutaneous tissue. Use of an aspirating syringe in which a negative pressure can be generated in the syringe affords a means of making such determination. Thus the appearance of blood in the syringe upon generation of the negative pressure would indicate location of the needle tip in a major blood vessel, while the lack of appearance of blood would indicate location of the tip in subcutaneous tissue. Depending upon the type of injection intended, the injection can then either proceed directly or if appropriate, the tip can be withdrawn and relocated.
Aspirating syringes are generally of two types, namely, they are either manually or automatically aspirated. In the manually aspirated type the plunger is retracted for a short distance within the barrel of the syringe. This retraction lowers the pressure within the syringe which leaves fluids at the needle tip which is then observable within the barrel of the syringe. From solid tissues no fluids will be drawn into the barrel. In the manually aspirated syringes the injection necessitates the use of both hands, one to hold the barrel, and the other to exert pressure in a rearward direction on the plunger. Such manually actuatable aspirating of syringes have the disadvantage that their proper use depends on very large measure on the degree of skill of the person administering the injections.
Aspiration in syringes of the automatic or self-aspirating type is effected by first inducing a positive pressure in a medicament-containing portion of the syringe. On release of the force inducing the positive pressure, a corresponding negative pressure in the syringe is generated thus giving rise to the aspirating effect. The present invention relates to the self-aspirating type syringes.
Ideally a self-aspirating hypodermic syringe should be: relatively simple in construction so as to minimize the cost of production; relatively simple to operate; capable of manipulation with one hand; adaptable to multiple self-aspirating actions; capable of expelling trapped air from the syringe prior to insertion of the needle into the injection site and prior to initiation of the self-aspirating action without either precluding self-aspirating action at a later time in the operation sequence of the syringe or otherwise rendering it inoperative.
The self-aspirating syringes provided by the present invention mimic, automatically, the slight rearward piston displacement withdrawal action of manually operable syringes, thus generating the slight negative pressure in the syringes essential for aspiration. The syringes of the present invention therefore obviate the disadvantage inherent in prior art syringes of the manual type, since the aspirating action is generated automatically which requires no special skill on the part of the practitioner.
These and other desirable objects will be explained as the description proceeds.
The invention will be described in reference to a pre-filled syringe; however, it is to be understood that a pre-filled cartridge, having essentially the same shape and other characteristics as a pre-filled syringe, is also intended to be described and covered by the appended claims.
SUMMARY OF THE INVENTION
The present invention comprises a syringe which is designed to be pre-filled and stored ready for injection. The syringe comprises:
(a) a barrel having an inner surface defining a cylindrical chamber for retaining an injectable fluid therein; a distal end terminating in a tapered tip to which an injection needle can be attached; and a proximal end for receiving a plunger;
(b) a cup-shaped plunger slideably mounted in said barrel and positioned within the barrel to provide a seal with the inner surface of the barrel, said plunger comprising:
(1) a distal convex face which is to interface with the injectable fluid contained in the barrel;
(2) a proximal fiat or concave face essentially parallel with the distal convex face;
(3) outside wall contiguous with the distal convex face having thereon: distal ring, proximal ring and center ring extending radially outwardly and forming a slideable seal with the inner surface of the barrel;
(4) inside wall having female threads;
(5) bottom rim which together with the inside wall defines a circular opening in the cup-shaped plunger through which a plunger rod can be inserted for engagement; and
(c) a plunger rod having distal and proximal ends, for engaging the plunger comprising:
(1) a plunger rod tip, located at the distal end of the plunger rod, having a semi-circular shape with convex face projecting in the direction of the plunger, the diameter of which is substantially smaller than the diameter of the plunger, and is designed to contact the proximal flat or concave inside face of the plunger at the center portion thereof;
(2) neck portion, contiguous with the plunger rod tip, designed to receive a slideable cylinder;
(3) slideable cylinder, positioned around the neck portion, comprising: an inside wall and an outside wall, the inside wall defines a cylinder the diameter of which is smaller than the diameter of the plunger rod tip so as to prevent the slideable cylinder slipping off of the neck portion, the outside wall having male threads for engagement of female threads of the plunger when the plunger rod is inserted into the plunger for operation of the syringe.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the assembled syringe containing a plunger and plunger rod, according to the present invention;
FIG. 2 is a longitudinal fragmentary cross-section of the syringe, plunger, and plunger rod equipped with a slideable cylinder taken along the line 2--2 of FIG. 1 with plunger and plunger rod inserted in the syringe;
FIG. 3 is an enlarged fragmentary cross-section of the plunger rod of FIG. 1;
FIG. 4 is an enlarged fragmentary cross-section of the plunger rod and plunger of FIG. 1 without plunger rod interfacing plunger;
FIG. 5 is an enlarged fragmentary cross-section of the plunger rod and plunger of FIG. 1 in a dynamic representation of the circumferential reduction produced when interfacing takes place between the plunger rod and plunger upon exerting force on the plunger when commencing an injection;
FIG. 6 is an enlarged fragmentary perspective view of the plunger rod and slidable cylinder of FIG. 1 when plunger rod is partially inserted in slidable cylinder;
FIG. 7 is an enlarged perspective view of the plunger rod and slidable cylinder of FIG. 1 when plunger rod is completely inserted in slidable cylinder;
FIG. 8 is a side elevational view of the plunger and slidable cylinder of FIG. 6;
FIG. 9 is a side elevational view of the plunger and plunger rod of FIG. 7;
FIG. 10 is a side elevational view of the plunger rod with the slideable cylinder removed;
FIG. 11 is a side elevational view of the slideable cylinder having male thread means;
FIG. 12 is a top plan view of the slideable cylinder of FIG. 11;
FIG. 13 is a longitudinal fragmentary cross section of a typical prior art syringe, plunger and plunger rod; and
FIG. 14 is an enlarged fragmentary cross section of the prior art plunger and plunger rod of FIG. 13.
______________________________________LIST OF REFERENCE NUMBERS USED______________________________________Syringe (generally designated) 10Barrel 20Inside wall of barrel 21Plunger 30Plunger rod 50Tapered tip of barrel at distal end 22Bore through tip of barrel 23Proximal end of barrel 24Finger hub of barrel 26Distal end of plunger rod 52Proximal end of plunger rod 60Handle of plunger rod 62Convex face of plunger 32Flat or concave face of plunger 34Outside wall of plunger 36Inside wall of plunger 38Bottom rim of plunger 39Distal ring (on outside wall of plunger) 40Proximal ring (on outside wall of plunger) 41Center ring (on outside wall of plunger) 42Female threads (of plunger on inside wall) 43Plunger rod tip 64Neck portion of plunger rod 66Slideable cylinder 68Outside wall of slideable cylinder 74Inside wall of slideable cylinder 72Male threads (on outside wall of slideable cylinder) 70______________________________________
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is shown a syringe generally designated 10 comprising: a barrel 20 having inside wall 21, a distal end terminating in a tapered tip 22 which has bore 23 therethrough, and a proximal end 24 to receive plunger 30; plunger 30 slideably positioned in barrel 20; and plunger rod 50 is attachable to plunger 30. Disposed about the periphery of proximal end 24 of the barrel 20 is finger hub 26 which facilitates holding barrel 20 during operation of plunger 30 by exerting a force on plunger rod 50. Plunger rod 50, having distal end 52 and proximal end 60 comprises handle 62 to facilitate exertion of force on plunger 30 by plunger rod 50 during operation of the syringe.
Syringe barrel 20 is made of an inert gas impermeable material including glass, however, it is preferably made of a substantially transparent material that is somewhat more flexible than glass, such as polyethylene, polypropylene, polystyrenes, acrylic and methacrylic polymers.
Plunger 30 is made of a compressible, elastomeric material, such as polyisoprene rubber. Plunger rod 50 is made essentially of the same material as the barrel.
Referring to FIGS. 1, 3 and 4, plunger 30 is slideably received in barrel 20 and is moved axially in the barrel by a manual force exerted on plunger rod 50 which is engageable with plunger 30. Plunger 30 in its relaxed state resembles an inverted cup having: a distal outside convex face 32; a proximal flat or concave inside face 34 essentially parallel with distal convex face 32; outside wall 36 contiguous with distal convex outside face 32; inside wall 38 contiguous with said flat or concave inside face 34; and bottom rim 39 which defines the circular opening in the cup shaped plunger 30. Distal convex face 32 of plunger 30 is to interface with a fluid contained in barrel 20.
Outside wall 36 of plunger 30 comprises: distal ring 40, proximal ring 41, and center ring 42, which are elastically deformable and extend radially outwardly from outside wall 36 and have, when taken together with plunger 30, a minimal diameter slightly in excess of the largest diameter of the working section of barrel 20. The rings form a sealing but slideable engagement with inside wall 21 of barrel 20.
Inside wall 38 of plunger 30 comprises female threads 43 to receive male threads 70 of plunger rod 50.
Referring to FIGS. 3, 4, 6, 7, 8, 9, 11 and 12, plunger rod 50 comprises: handle 62 located at proximal end 60 thereof to facilitate exertion of manual force thereon by an operator; plunger rod tip 64 having a semi-circular shape with convex face projecting in the direction of plunger and the diameter of which is substantially smaller than the diameter of the plunger, located at the distal end 52 of plunger rod 50, extending axially forwardly from distal end 52 of plunger rod 50 and is adapted to contact the proximal flat or concave inside face 34 at the center portion of plunger 30 upon exertion of pressure on plunger 30; neck portion 66 of plunger rod 50 located between plunger rod tip 64 and distal end 52 of plunger rod 50 is adapted to receive slideable cylinder 68 which comprises outside wall 74 and inside wall 72. Outside wall 74 has male threads 70 to engage female threads 43 of plunger 30. Inside wall 72 defines a cylinder the diameter of which is somewhat smaller than the diameter of plunger rod tip 64 so as to prevent slideable cylinder 68 slipping off the neck portion 66 of plunger rod 50.
The operation of the pre-filled syringe of the present invention is as follows.
Plunger 30 is inserted into barrel 20 of syringe 10 at the proximal end 24 thereof past finger hub 26 so that barrel 20 may be placed pointing vertically upward with its distal end on a flat surface, such as a filling line, without interference from plunger 30. Barrel 20 is filled with the desired liquid, such as a medicament or a diagnostic imaging medium, by way of bore 23 through tapered tip 22 and capped. The liquid could be pre-sterilized in bulk and filled into the syringe barrel using aseptic technique or the prefilled filled syringe may be sterilized by autoclaving or other means at this point.
An alternate filling procedure is to cap the tapered tip 22 and fill the medication from the proximal end of barrel 20. Plunger 30 is then inserted into barrel 20 after filling syringe 10.
The pre-filled, sterilized syringe is then packaged separately from a hypodermic needle to be assembled just prior to use. Preparatory for injection, the hypodermic needle is fitted onto the tapered distal end 22 of barrel 20. Slideable cylinder 68 at the distal end of plunger rod 50 is threaded into plunger 30 and tightened to achieve a snug engagement. The practitioner then gains entry into the desired mammalian site, such as a blood vessel, using conventional venipuncture technique. At this point of the procedure the plunger rod 50 and plunger 30 are in a static engagement. As shown in FIG. 4, female threads 43 of plunger 30 engage male threads 70 of slideable cylinder 68, but plunger tip 64 does not contact flat or concave face 34 of plunger 30 and does not exert pressure thereon.
When the operator exerts a relatively slight pressure on plunger rod 50 in a vertical upward direction, the following circumferential deformation of the plunger takes place as shown in FIG. 5: convex face 32 of plunger 30 is extended upward for distance "a" while distal ring 40, proximal ring 41 and center ring 42 are pulled inward by elastic tension forces for distance "b", "c" and "d" respectively. As illustrated, distance "a" is the largest, followed by distances "b", "c " and "d". This circumferential deformation of the plunger expels head gas from the syringe, i.e. aspirates the syringe. Upon releasing the pressure applied on plunger rod 50, plunger 30 returns to its static position thereby creating a vacuum in barrel 20 and drawing body fluid from the patient indicating that the desired site had been entered and the injection may commence. The operator then, again, exerts pressure on plunger rod 50 which results in the same circumferential deformation of plunger 30 as described with respect to aspirating the syringe. Referring to proximal ring 41, distal ring 40 and center ring 42, it is clear that the force they now exert on the inside wall 21 of barrel 20 is reduced in direct proportion to the distance "b", "d" and "d" created by the circumferential deformation. As a result, the plunger moves relatively easily in the barrel allowing convenient delivery of the liquid into the injection site. This advantage of the present invention is even more pronounced when the pre-filled syringe is kept in storage for extended time periods during which time the plunger tends to seize in the barrel and the interfacial force between the plunger and the inside wall of the barrel is extremely difficult to break in the axial direction. In the syringe of the present invention the force exerted on the plunger pulls the distal, proximal and center rings inwardly and greatly reduces the interfacial force between the plunger and the inside wall of the barrel.
It will be appreciated from the foregoing description that the syringe of the instant invention possess all the attributes of an ideal syringe for both aspiration and injection as enumerated above. That is, the syringe is simple in construction, thus minimizing the cost of production; it is simple to operate; it is capable of manipulation with one hand; it is capable of multiple self-aspirating actions with each cartridge; and it is capable of expelling air trapped within the cartridge either prior to initiation of the self-aspirating action or at any time during the sequence of actions necessary for injection of the syringe content without, on the one hand, precluding self-aspirating action at any point in the sequence or, on the other, rendering the self-aspirating action inoperative.
Prior art syringes having generally similar constructions to the present invention are illustrated in FIGS. 13 and 14 wherein corresponding parts are designated with the same numerals with primes (') thereon.
While convex outside face 32' is present, there is no concave inside face 34' in plunger 30', i.e. the inside face 34' of plunger 30 is flat. Plunger rod tip 64' does not exist, but instead, the plunger rod face, which communicates with inside non-convex face 34', is flat. In operation of the prior art syringe, the force exerted on plunger 30' by plunger rod 50' through plunger rod tip 64' will not result in a circumferential reduction of rings 40', 41' and 42' and, consequently, will not result in the reduction of syringing force that is necessary to complete the injection. The illustrated prior art syringe also lacks selfaspirating capability since upon exertion of force on plunger rod 50', convex face 32' of plunger 30' will not deform, and upon releasing the force, will not regain its static configuration.
Having thus described the invention and the advantages thereof, it is considered that the invention is to be broadly construed and limited only by the following claims. | Disclosed are pre-filled syringes equipped with an improved plunger and a plunger rod, characterized by a leak-proof seal and easy sliding property. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a carpet shearing machine for modular carpet. In the processing of pile carpet it is desirable to shear the pile to obtain a uniform height for the carpet.
Previously, carpet was produced and processed in rolls which were sheared by continuously passing the rolled carpet through the shears. The rolled material was passed through the shear in one direction and the equipment was not capable of handling small modular pieces of carpet such as 12×12 or 24×24 inch modules.
A method of processing modular carpet was to place the carpet material on a stationary table and to pass the shear over the carpet. This equipment did not adequately trim and clean the pile carpet. Additionally, the equipment was difficult to use and maintain.
SUMMARY OF THE INVENTION
Modular pile carpet, i.e. carpet which is not prepared and processed in rolls and is typically of 12 inch by 12 inch or 24 inch by 24 inch squares is becoming more popular. The present invention relates to a carpet shearing machine for shearing this modular pile carpet. The shearing machine of the present invention can accommodate various sizes of modular pile carpeting.
Additionally, the shearing machine of the present invention may be readily adjusted to permit the shearing of different height pile carpeting.
Further, the shearing machine of the present invention permits a single operator to process the modular carpeting and is easy to operate and maintain.
It is a specific object of the present invention to provide a carpet shearing machine which can accommodate various sizes of modular carpet and which will permit the carpet to be passed through the shear and thereafter the shear is raised to permit the carpet to return to its original position for removal from the machine. Various further and more specific purposes, features and advantages will be come apparent from the detailed description given below and taken in connection with the accompanying drawings which form part of this specification and illustrates by way of example, the preferred embodiment of the device of the present invention.
DESCRIPTION OF THE DRAWINGS
In the following description and in the claims, items will be identified by specific names for convenience, but such names are intended to be as generic in their application to similar items as the art will permit. Like reference characters denote like parts in the several figures of the drawings, in which:
FIG. 1 is a front view of the carpet shearing apparatus of the present invention;
FIG. 2 is a side view of the carpet shearing apparatus of FIG. 1;
FIG. 3 is a rear view of the carpet shearing apparatus of FIG. 1; and
FIG. 4 is a partial sectional view of the shear and brush mechanism of the apparatus of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and in particular to FIGS. 1, 2, 3 and 4, the apparatus of the present invention consists of a frame member 10 having legs 12 with are provided with suitable cross-braces 14. Attached to the cross-braces 14 at each end of the frame member 10 is a table guide arm 16. Each pair of table guide arms 16 are provided with shafts 18 which contain sprockets 20 for accommodating a drive chain 22 on each side of the frame. The shaft 18 at one end of the frame member 10 has connected thereto a drive sprocket 24 which is connected to a suitable drive motor 26. The motor 26 is connected to the frame 10 by suitable bracing and mounting 26A. A table 28 having a surface 30 with plurality of openings 32 therein is positioned between the table guide arms 16. The table 28 is connected on each side to the drive chain's 22 which serves to move the table from the front to the rear of the frame member 10. A suction or vacuum device (not shown) is attached by the hose 30 to the underside of the table 28 through the duct 34 such that the suction or negative air pressure may be established through the openings 32 in the table 28. The drive motor 26 is reversible such that the table 28 can be moved forward and backward by the drive chains 22. A limit switch (not shown) is provided on the frame and is engagable by the table 28 as it moves from the front of the machine to the rear of the machine. This switch is connected to the motor 26 for reversing the motor when engaged.
Sheet metal sides 36 are connected by suitable means to the cross-braces 14 to protect an operator from the drive chains 22. (Note that in FIG. 2 part of the sheet metal side 36 is not shown to provide a better view of the drive chains 22.)
East side of the frame member 10 is provided with a pivotable arm mounting bracket 38. A pivotable arm 40 is connected to the pivotable arms mounting bracket 38 by suitable means such as a pin 42. The pivotable arm mounting bracket 38 is provided with an adjustment bolt 40A for raising and lowering the position of the pin 42 on said bracket.
Mounted on the pivotable arm 40 by suitable means is a shaft 44 which contains the shear 46. If desired a shaft 48 for a brush 50 for aligning the pile on the carpet may be connected to the pivotable arm 40 in front of the shear 46. A shaft 52 is attached to the legs 12 by mounting brackets 54. Each of the pivotable arms 40 are connected by means of linkage members 55 to the shaft 52. Additionally, connected to the pivotable arm 40 at the linkage member 55 is an arm or stop 56. The stop 56 may be raised or lowered by means of the adjustment wheel 58 which is connected through the shaft 60 and sprocket mechanism 62. An air cylinder 64 is mounted on the frame 10 and is connected to the shaft 52 such that when the air cylinder 64 is in its normal position, the pivotable arms 40 are at the height established by the adjustment 40A and stops 56 and the shear 46 and brushes 50 are positioned a predetermined distance above the table 28. When the air cylinder 46 is activated the shaft 52 is turned which through the linkage members 55 causes the pivotable arms 40 to raise. The air cylinder 46 in activated by the table 28 engaging the limit switch as previously discussed.
The shaft 48 is provided with a drive pulley 66 and the shaft 44 is provided with a drive pulley 68. The pulleys 66 and 68 are connected by means of belts 70 to the drive motor and pulley 72. This arrangement of the belts 70 permits the shafts 44 and 48 to be raised and lowered by the pivotable arms 40 without interruption or affecting the rotation of the shears 46 and brush 50.
A suction flume 74 is mounted on the pivotable arm 40 just above the nip area of the shear 46 with the carpet. A motor 76 and impeller 78 are connected by conduit 80 (partly shown) to the suction flume 74 for removing any fiber material removed from the carpet by the shear 46.
In the operation of the equipment, the carpeting 82 to be sheared is placed on the table 28. The suction device is activated which will cause the air pressure through the openings 32 in the table 28 to hold the carpeting 82 in place. The drive motor and pulley 72 is activated causing the brush 50 and shear 46 to be rotated. The table 28 is then moved by the drive chain 22 from its first or load position toward the shear 46. As the carpet 82 passes beneath the shear 46, the pile is sheared with the sheared pieces being removed through the suction flume 74. After the table 28 has passed beneath the shear 46 it engages the limit switch at its second position. This limit switch serves to activate the air cylinder 64, raising the pivotable arm 40 and reversing the drive motor 26 and drive chains 22 to return the table 28 to its original position. When the table 28 reaches its original position a second limit switch (not shown) is engaged which deactivates the air cylinder 64, lowering the pivotable arm 40 to the stops 56. The second limit switch also permits the drive motor 26 to again be reversed for subsequently moving the table 28.
While the invention has been described and illustrated with respect to a certain preferred example, it will be understood by those skilled in the art after understanding the principle of the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention. | A carpet shearing machine for modular carpet which includes a moveable table which is provided with means for holding the modular carpet. A carpet shear is positioned on a moveable frame which is adjustable to a predetermined distance above the moveable table. The moveable frame may be pivoted and raised above the moveable table such that the modular carpet on the table may be passed beneath and through the shear and thereafter the shear is raised to permit the moveable table to return to its original position. | 3 |
TECHNICAL FIELD
[0001] The present invention relates to a pattern measurement device which measures a pattern on the basis of information obtained by a charged particle beam device, and in particular to a pattern measurement device for measuring a random pattern such as polymers used in self-assembly lithography, an evaluation method, a computer program, and a storage medium capable of storing the computer program.
BACKGROUND ART
[0002] With recent advance of integration of semiconductor patterns, evaluation of workmanship in manufacture processes and research and development processes is becoming more important. On the other hand, DSA (Directed Self Assembly) technique attracts attention as a technique that makes it possible to shrink sizes of semiconductor patterns. The DSA is a new patterning technique utilizing the self-assembly phenomenon of polymers. The DSA is a technique employing a micro phase separation phenomenon in which macromolecular BCP (block copolymer) forms regular domains of nanometer-size. The shape and size of a pattern can be controlled by designing a molecular structure and a molecular weight of the BCP.
[0003] Since special devices or facilities are not used, it is possible to save the cost. In recent years, development of a semiconductor manufacture process using this method has been promoted. By coating the top of a substrate with BCP and applying thermal annealing, the BCP conducts self-assembly and conducts phase separation to a peculiar shape. For applying the BCP to actual semiconductor manufacture, it is necessary to cause the BCP to self-assemble to a desired shape. Therefore, it is necessary to control and induce the self-assembly phenomenon chemically or physically.
[0004] Patent Literature 1 describes an example of observing a pattern formed by the DSA technique with a scanning electron microscope and an example of conducting dimension measurement of a pattern.
CITATION LIST
Patent Literature
[0005] Patent Literature 1: JP-A-2010-269304 (corresponding U.S. Pat. No. 8,114,306)
SUMMARY OF INVENTION
Technical Problem
[0006] The greatest feature of patterning using the DSA is that the pitch and dimension of a pattern are determined by a material. In other words, the workmanship of a pattern depends upon to what degree the material can be manufactured according to specifications. Therefore, it is desirable to conduct one-hundred percent inspection every shipment. Furthermore, it is expected that an evaluation device capable of evaluating a material simply and with high precision will be demanded.
[0007] As an evaluation technique of a BCP material, a method of preparing a guide pattern for arranging the BCP material in a desired shape on a substrate beforehand, arranging the BCP material along the guide pattern, and thereafter conducting evaluation, and a method of coating the top of a substrate neutralized without using a guide pattern, with a BCP material and evaluating workmanship as a fingerprint pattern are conceivable. In a case where a guide pattern is used, the BCP material is arranged in a desired shape, and consequently quantification of the shape can be conducted simply. On the other hand, since workmanship of the guide pattern exerts an influence upon the BCP pattern, a case where pure material evaluation is not conducted is conceivable.
[0008] In the case of evaluation using the fingerprint, there is no influence of a guide pattern and consequently pure evaluation of the material is possible. Since there are curves and undulation of a pattern peculiar to the fingerprint, however, quantification is difficult with a simple method. Even if pitch measurement using Fourier analysis is conducted, these kinds of unnecessary information are included, resulting in lowered precision. Any evaluation method for evaluating the fingerprint pattern itself is not discussed at all in Patent Literature 1.
[0009] Hereafter, a pattern measurement device, method, and computer program aiming at evaluating a random pattern such as a fingerprint pattern quantitatively and with high precision.
Solution to Problem
[0010] As one aspect for achieving the object, the present inventors propose a pattern measurement device that measures a pattern on a sample on the basis of an image acquired by a charged particle beam, and that selectively extracts straight line portions of a pattern on the sample or portions which can be approximated by a straight line, and outputs at least one of measurement of a distance between the extracted portions, a ratio of the extracted portions in a predetermined region, and lengths of the extracted portions, and a computer program which causes a computer to execute the arithmetic operation.
[0011] Furthermore, as a more concrete aspect, the present inventors propose a pattern measurement device that finds a frequency depending upon a distance value between extracted portions and outputs a distance value at which the frequency satisfies a predetermined condition as a pattern distance, and a computer program which causes a computer to execute the output.
[0012] In addition, as another aspect for achieving the object, the present inventors propose a pattern evaluation method for evaluating a polymer used in self-assembly lithography, including selectively extracting straight line portions of patterns or portions that can be approximated with a straight line from within a fingerprint pattern image obtained by a charged particle beam device, and finding at least one of measurement of a distance between the extracted portions, a ratio of the extracted portions in a predetermined region, and lengths of the extracted portions.
[0013] Furthermore, the present inventors propose a pattern measurement device that finds center lines of a pattern on a sample, and executes measurement of variations on the basis of measurement of a distance between the center lines, or measurement of distances at a plurality of places between a center line and edges adjacent to the center line, or distances between edges on both sides with a center line between.
Advantageous Effects of Invention
[0014] According to the above-described configuration, it becomes possible to evaluate a random pattern such as a fingerprint pattern quantitatively and with high precision.
BRIEF DESCRIPTION OF DRAWINGS
[0015] [ FIG. 1 ] is a diagram showing an outline of a scanning electron microscope;
[0016] [ FIG. 2 ] is a flow chart showing a measurement process of a fingerprint pattern;
[0017] [ FIG. 3 ] is an outline diagram of a fingerprint pattern;
[0018] [ FIG. 4 ] is a diagram showing an SEM image of a fingerprint pattern, and an example of a contour line image obtained by extracting center lines of the pattern with respect to the SEM image;
[0019] [ FIG. 5 ] is a diagram showing a process for measuring a distance between extracted center lines;
[0020] [ FIG. 6 ] is a histogram showing a relation between a distance value between center lines in a predetermined area and a frequency of regions indicating the distance value;
[0021] [ FIG. 7 ] is a diagram showing an example of evaluation of roughness of a fingerprint pattern;
[0022] [ FIG. 8 ] is a diagram showing an outline of a pattern measurement device which executes pattern measurement by using image information obtained by a scanning electron microscope; and
[0023] [ FIG. 9 ] is a diagram showing an example of a GUI (Graphical User Interface) screen for setting measurement conditions.
DESCRIPTION OF EMBODIMENTS
[0024] Embodiments described hereafter mainly relate to a patterning measurement method and a measurement device in a patterning technique utilizing micro phase separation of block copolymer including two kinds of polymer.
[0025] With the size shrinking of semiconductor, it is becoming impossible for patterning using simple lithography to cope with the size shrinking As a technique for prolonging the life of lithography, methods such as the multiple patterning method in which lithography processes of a plurality of times are combined and a nano imprint technique have been conceived. From the viewpoint of cost and implementation possibility, however, any method has not made a decisive hit. The present embodiment relates to a device, method, and computer program for properly evaluating polymers used in the DSA technique anticipated as an effective patterning technique, and relates to a storage medium capable of storing the computer program.
[0026] In the present embodiment, evaluation is conducted by using only a portion of a fingerprint pattern where the pattern forms a straight line in order to improve the precision of evaluation using the fingerprint pattern. As a result, quantification of a shape with high precision using only a straight line portion without being affected by the workmanship of a guide patter becomes possible. Specifically, when acquiring an image of a fingerprint pattern and conducting image processing, a curved portion is masked and evaluation is conducted by using only a straight line portion. Hereafter, an evaluation method of the fingerprint pattern will be described in detail with reference to the drawings.
[0027] A pattern measurement method will now be described. In an SEM 001 shown in FIG. 1 , an SEM image of a sample is acquired under previously set imaging conditions (such as a magnification and an acceleration voltage of an irradiation beam). Specifically, an electron beam 102 emitted from an electron gun 101 in the SEM 001 is converged by a condenser lens 103 . Scanning in an X direction and a Y direction (in a plane perpendicular to the drawing in FIG. 1 ) with the electron beam is conducted by a deflector 104 . The electron beam is focused on a surface of a sample 106 with a measurement target pattern formed thereon, by an object lens 105 . The surface of the sample 106 is scanned and irradiated with the electron beam. Although illustration is omitted in FIG. 1( a ), the sample 106 is placed on a table and is capable of moving in the plane. Control is exercised to position a desired area on the surface of the sample 106 in an area irradiated with the electron beam 102 . A portion of secondary electrons generated from the surface of the sample 106 irradiated with the electron beam 102 is detected by a detector 107 , and converted to an electric signal. The electric signal is sent to a general control & image processing unit 108 , and an SEM image is created. In an arithmetic operation unit 109 , the SEM image is processed and dimensions of the pattern are calculated. Results are displayed on a screen in an output unit 110 . The general control & image processing unit 108 exercises control of the whole SEM 001 including the table on which the sample 106 is placed and which is not illustrated.
[0028] A processing procedure in the arithmetic operation unit 109 is shown in FIG. 2 . First, as described above, the general control & image processing unit 108 controls the SEM 001 and acquires an SEM image of a measurement target pattern (S 0001 ). Then, the arithmetic operation unit receives the SEM image acquired by the general control & image processing unit 108 , processes the SEM image, and conducts extraction of pattern center lines (S 0002 ). Details of measurement at the step (S 0002 ) will be described later.
[0029] Then, at step (S 0003 ), a decision as to the linearity of a center line is conducted on the basis of inclination of the center line per unit length. In a case where it is confirmed that an area is a straight line area as a result of this decision, inclinations of two center lines are compared at next step (S 0004 ), and a distance is measured only in parallel portions (S 0005 ). This processing is conducted for all measurement points which are set in the image. After measurement is conducted at all points, an average measured value is calculated at step (S 0006 ). As a result, an inherent pitch of the BCP material is found. An extracted center line is displayed to be superposed on the SEM image on the GUI.
[0030] By the way, in the present embodiment, a device in which a computer including an image processing processor (decision unit) that conducts quantification of a finger print pattern shape described hereafter on the basis of a signal of secondary electrons or the like is included as a portion of a scanning electron microscope device is exemplified as an example of a pattern measurement device. However, the pattern measurement device is not restricted to the exemplified device. For example, an external measurement device including an interface for acquiring information (such as a secondary electron signal, signal waveform information based on detection of secondary electrons, a two-dimensional image signal, or contour line information of pattern edges extracted from the image) based on a signal acquired by the scanning electron microscope, and an arithmetic operation device corresponding to the above-described image processing processor may conduct quantification of a pattern shape described later. It is also possible to previously register a program which conducts processing described later into a storage medium and cause a processor which supplies a necessary signal to a scanning electron microscope or the like to execute the program. In other words, the ensuing description is also description of a program or a program product which can be executed in a pattern measurement device such as a scanning electron microscope.
[0031] By the way, the scanning electron microscope using an electron beam has been described heretofore as an example of the charged particle beam device. However, the charged particle beam device is not restricted to the scanning electron microscope using an electron beam. For example, the charged particle beam device may be an ion beam irradiation device using an ion beam.
[0032] FIG. 8 is a diagram showing an example of a pattern measurement device which executes pattern measurement by using image information obtained by a scanning electron microscope. A pattern measurement device 801 is an arithmetic operation device which executes various kinds of processing along a previously stored program. The pattern measurement device 801 includes a contour line extraction unit 802 which extracts contour lines from image data output in the SEM 001 exemplified in FIG. 1 . By the way, in a case where a contour line extraction unit is mounted on the SEM 001 , this function can be omitted. As for the extracted contour lines, a straight line portion is selectively extracted by a straight line portion extraction unit 803 . An inter-center-line dimension measurement unit 804 measures a distance (pitch) between center lines of a pattern on the basis of the extracted straight line portion as described later. A histogram creation unit 805 finds a frequency of each measurement result as regards results of measurement conducted by the inter-center-line dimension measurement unit 804 , and creates a histogram. A measured value output unit 808 outputs a measurement result of a specific frequency to a display device in, for example, an input device 809 .
[0033] Furthermore, the pattern measurement device 901 can function as a roughness measurement device as well. In a case where the pattern measurement device functions as a roughness measurement device, first, a smoothing processing unit 806 conducts smoothing processing on the obtained image data and contour line data, a center line-edge dimension measurement unit 807 measures a plurality of dimensions between edges of a pattern and center lines of the pattern subjected to the smoothing processing, and the measurement value output unit 808 outputs results of the measurement to the display device or the like. Operation of the pattern measurement device 801 will be further described.
[0034] FIG. 9 is a diagram showing an example of a GUI screen for setting conditions of measurement conducted by the scanning electron microscope. It becomes possible for an operator to select proper conditions along a measurement target by displaying such a GUI on the display device in, for example, the input device 809 . In the GUI exemplified in FIG. 9 , a window 901 for selecting a kind of a measurement object (target) is provided. In the example in FIG. 9 , Polymer is selected. Furthermore, a window 902 for inputting Target Orientation (direction of the target) is provided, and Random is selected in the example in FIG. 9 . In the present example, selection contents in a measurement item selection window (Measurement Option) 903 change on the basis of inputs to the windows 901 and 902 . For example, if Line (line pattern) and Vertical are selected respectively in windows 901 and 902 , the measurement target is a line pattern which is long in a longitudinal direction, and consequently it becomes possible to select measurement items suitable for the line pattern, such as measurement of a dimension between line edges and measurement of a line pitch, in the window 903 .
[0035] As for a polymer selected in the example in FIG. 9 , an edge peak does not appear unlike an ordinary wiring pattern. Therefore, it becomes possible to select measurement items for extracting center lines of the pattern in the whole image and then finding distances between the center lines by selecting, for example, (Pattern Center Contour). Furthermore, an example in which a length of a straight line portion (Length Straight) and a ratio of a straight line portion to a curve portion in the pattern (Ratio Straight Curve) are selected is shown in FIG. 9 .
[0036] Contents of these measurement items will be described later. Besides, it becomes possible to execute measurement based upon selection of a suitable operation program by selecting coordinates (Location) of a measurement target, a field of vision size (FOV size) and so forth and transmitting these measurement conditions to the SEM or the pattern measurement device 801 .
[0037] Hereafter, an outline of a fingerprint pattern which is a measurement target in the present embodiment of the scanning electron microscope will be described.
[0038] FIG. 3 shows an outline of a fingerprint pattern. The fingerprint pattern takes a structure in which a pattern formed by two kinds of polymer (referred to as A and B) stands erect on a substrate 301 and polymer A 302 and polymer B 303 are arranged alternately in a fingerprint form. In lithography using the Directed-Self-Assembly technique, compositions (such as molecular weights, molecular chain lengths, and a separation degree between the two kinds of polymer) of polymers in use and their variations affect workmanship of the pattern shape. When introducing a new material or process, therefore, it is necessary to evaluate the workmanship of polymers as materials and confirm patterning capability. The fingerprint pattern is used at that time. The fingerprint pattern is obtained by neutralizing a Si substrate, then coating the Si substrate with polymers having self-assembly capability, and conducting anneal processing at a determinate temperature. The shape (such as a line width, pitch, curvature of a curved place, and a length of a straight line portion) of the fingerprint pattern differs depending upon the material, and the shape becomes a clue to material evaluation.
[0039] Hereafter, a quantification technique of the pattern shape based on an image will be described. An SEM image shown in FIG. 4( a ) is an image obtained by observing the pattern provided with a difference in level between the two kinds of polymer by selectively etching one of the polymers after the annealing. At this time in the image, a difference in polymer appears as a difference in luminance. Hereafter, a portion 401 having a high luminance in the image is referred to as polymer A, and a portion 402 having a low luminance in the image is referred to as polymer B.
[0040] The pitch of repetition of the polymer A and the polymer B is inherent depending upon the configuration (molecular weights respectively of the polymer A and the polymer B, or composition of additives) of the BCP material. Therefore, it can be determined whether the BCP material has a composition as designed, by measuring a pattern pitch (a distance between center lines). By the way, in the fingerprint pattern after the annealing, there is no difference in level between the two kinds of polymer. In the SEM, therefore, it is difficult to obtain a contrast in some cases. At that time, an image may be picked up after the visibility of the pattern in the SEM is improved by conducting etching after the annealing. Furthermore, irradiation with the electron beam conducted by the SEM functions to contract one polymer in some cases. At that time, irradiation with the electron beam should be conducted before image pickup, and an image for evaluation should be acquired after the visibility is improved.
[0041] Hereafter, a technique of measuring the pattern pitch will be described. First, the SEM 001 or the contour line extraction unit 802 detects a point having a high gradation value from an SEM image and extracts a center line of a pattern formed by the polymer A. Extraction of a center line is executed by, for example, removing noise from the image by using a Gauss filter or the like and then conducting binarization processing to divide the polymer A and the polymer B respectively to white and black. In addition, a center line is obtained by conducting thinning processing until a region of the polymer A (white) becomes one pixel width. It is also possible to adopt another thinning processing method.
[0042] An extraction example of center lines is shown in FIG. 4( b ), and a flow of measurement is shown in FIG. 5 . The straight line portion extraction unit 803 arranges reference points at predetermined or arbitrary intervals along a center line 501 formed by the polymer A. And the straight line portion extraction unit 803 approximates the reference points 502 with a straight line 503 , and detects center line point rows 504 and 505 of adjacent patterns caused by the polymer A intersecting a normal line 506 of the straight line 503 . The straight line portion extraction unit 803 approximates a detected point row with a straight line, and compares inclination of the straight line with that of an adjacent straight line. In a case where a difference in inclination is small, the two straight lines ( 503 , 505 ) are regarded as parallel. The inter-center-line dimension measurement unit 804 measures a distance 507 between the two straight line, and defines the distance 507 as pitch between two patterns. In a case where inclinations differ largely, the two straight lines ( 503 , 504 ) are not parallel, and consequently measurement of the distance is not conducted.
[0043] By the way, as a technique for selectively extracting a straight line portion, for example, it is conceivable to define a segment that can be regarded as a straight line over a length of at least a predetermined value or a predetermined number of points, as a straight line and exclude a segment in which a straight line portion is less than a predetermined value or less than a predetermined number of points in length from a measurement target as other than a straight line. Furthermore, it is also possible to find a correlation coefficient between an approximate straight line and a point row at the time when straight line approximation is conducted, exclude a portion having a value of the correlation coefficient less than a preset threshold from measurement targets, and define remaining portions as straight lines (as measurement targets). Furthermore, it is also possible to find curvature of a point row, exclude a portion having curvature of at least a predetermined threshold or larger than a predetermined threshold from measurement targets, and define remaining portions as straight lines (as measurement targets).
[0044] Furthermore, in a case where a measurement target region is to be further selected from the straight line portion extracted as described above, a dimension between segments that are adjacent to each other (another segment is not included between the segments) and that have a relative angle between less than a predetermined value should be measured selectively or output.
[0045] This measurement is conducted for the whole SEM image or a predetermined region in the SEM image, and as many measured values of the pitch as the number of point rows on the center lines are found. If the histogram creation unit 805 conducts histogram analysis on them as shown in FIG. 6 , a pitch having the highest frequency can be found as the inherent pitch of the material. The measured value output unit 808 outputs a dimension between segments that belong to straight line portions and that can be regarded as parallel to an adjacent contour line, to the display device in the input device 809 or the like as a measurement result.
[0046] Even for a pattern such as the fingerprint pattern, it becomes possible to conduct the aimed measurement (pitch measurement) with high precision by making a measured value of a high frequency selectively as a measurement result in this way. By the way, in the present embodiment, an example of adopting a measured value that is the highest in frequency as a measurement result has been described. However, a measured value that has a specific frequency other than the highest frequency may be output as a measurement result according to the object.
[0047] By the way, in the above-described technique, it must be determined whether two patterns are parallel on the basis of inclination of a point row, in all detection points of pattern centers existing in the whole screen of an SEM image. Therefore, it takes long time to conduct processing in some cases. In a case where it is desired to give priority to speed up of the processing, detection points should be thinned, or it is possible to previously extract parallel portions from the SEM image and conduct pitch measurement only in that portion. In that case, it can be implemented by using an image processing technique such as the Hough transform which is generally known as straight line extraction means on a digital image.
[0048] In a case where a length or ratio of a straight line region in the finger print pattern is to be measured as well, extraction of a straight line region is possible by using a technique similar to that described above. For example, the ratio of straight line regions can be found by finding a length of portions judged to be straight lines in the sum total of lengths of center lines in the whole pattern.
[0049] The finger print pattern conducts self-assembly by annealing, and lines up as a pattern shape of a semiconductor device. Many of patterns formed on the basis of the fingerprint pattern are line patterns having a straight line shape. As for the fingerprint pattern as well, it can be said that a material including many straight line portions is a material suitable for patterning. Therefore, it becomes possible to conduct quantitative analysis of polymers applied to the DSA technique and conduct proper selection of polymers based on the quantitative analysis by finding a ratio of straight line portions. By the way, the ratio of straight line portions to whole segments included in the visual field or a predetermined region in the visual filed may be output, or the ratio of straight line portions to curved line portions may be output.
[0050] A method for measuring LER (Line Edge Roughness) of a pattern will now be described with reference to FIG. 7 . FIG. 7 is a schematic diagram of an SEM image of the fingerprint pattern, and represents a fingerprint pattern including a pattern A 701 and a pattern B 702 . First, it is necessary to define a line that becomes a reference of LER. As for this, a segment 703 coupling a point row on a center line can be used. If the center line-edge dimension measurement unit 807 extracts left and right edges ( 704 , 705 ) of the pattern A besides the center line 703 and measures a distance 710 to an edge detection point located in a normal direction of the center line, variations of the distance 710 can be defined as the LER. Or since variations of the line width is a square sum of edge position variations respectively of edges on both sides, a distance (line width) between edge detection points located in the normal direction on both sides with the center line between is measured and variations of edges on one side is calculated from variations of the line width.
[0051] Since variations of the center line itself exert an influence upon the LER, however, it is necessary that variations of the center line are previously removed. The variations can be removed by finding a center line after the smoothing processing unit 806 smoothes an image, or by smoothing found center lines. Since the fluctuation component and roughness peculiar to the fingerprint have a great difference in frequency, a method of providing a threshold for the frequency and masking the fluctuation component and then reconstructing an image is also effective.
[0052] In the foregoing method, extraction of a straight line portion from an SEM image already acquired and evaluation have been described. However, it is also possible to search for a straight line portion from an image of low magnification acquired previously by using a similar method, re-acquire an SEM image of the straight line portion, and then conduct evaluation.
[0053] The pattern measurement technique disclosed in the present specification can be applied to an electron microscope or a charged particle beam device similar to the electron microscope as long as it is capable of acquiring an image.
REFERENCE SIGNS LIST
[0054] 001 : SEM
[0055] 101 : Electron gun
[0056] 102 : Electron beam
[0057] 103 : Condenser lens
[0058] 104 : Deflector
[0059] 105 : Object lens
[0060] 106 : Sample
[0061] 107 : Detector
[0062] 108 : Image processing unit
[0063] 109 : Arithmetic operation unit
[0064] 110 : Output unit | The purpose of the present invention is to provide a pattern measurement device which evaluates quantitatively and with high precision random patterns such as finger print patterns. In order to fulfill this purpose, a pattern measurement device which measures the pattern on a sample on the basis of an image acquired by a charged particle beam is proposed which selectively extracts linear or linearly approximable parts of the pattern on the sample, and outputs at least one of the following: the measurement of the distance between the extracted parts, the ratio of said extracted parts in a prescribed region, and the length of said extracted parts. Further, as a more specific embodiment, a pattern measurement device is proposed which calculates a frequency depending on a distance value between extracted parts, and outputs, as a pattern distance, distance values for which said frequency fulfills a prescribed condition. | 6 |
This invention is a Continuation-In-Part of U.S. patent application Ser. No. 12/533,806 filed Jul. 31, 2009.
FIELD OF THE INVENTION
This invention relates to water damper controls for storm water treatment systems, manmade ponds and pools, natural lakes, ponds, actuaries and other water ways, and in particular to devices, apparatus, systems and methods of using a damper panel system to isolate a water treatment control structure from unwanted water inflow where a slidable door on wheels can be sealed in place with rotatable cams pushing one side of the door against portions of the tracks, so that operators can unlock the sealed door and pull out the door by hand when needed, where the door can slide upward to different height positions, and slide downward to different height position.
BACKGROUND AND PRIOR ART
There are federal clean water requirements that require water bodies such as lakes and rivers must meet strict minimal water quality specifications. To achieve these requirements, stormwater drainage pipes often require treatment before conveying stormwater into receiving water bodies. As a result, a wide variety of technologies have been developed to treat stormwater and improve the water quality. A common variety of stormwater treatment systems are hydrodynamic separators such as baffle type boxes and vortex systems. However, over time stormwater treatment systems often will fill with collected debris and will require service to remove the collected debris.
The servicing of a stormwater treatment structure typically requires the use of a vacuum truck that will suck out the collected solids and water within the structure. After the vacuum truck removes the debris and water from the stormwater structure, the vacuum truck transfers those contents to a processing facility for proper disposal. However, servicing stormwater structures is often complicated by unwanted water flow running into the stormwater structures during the service procedure. This unwanted water flow typically originates from high water levels in lakes and rivers adjacent to the treatment structure, or from an upstream base flow.
While the vacuum truck is removing water and debris from the treatment structure, water sometimes continues to flow in. Often the amount of water flowing into the treatment structure during servicing exceeds the rate at which the vacuum truck can remove the water. Having water enter the stormwater structure during servicing procedure reduces the effectiveness and efficiency of the service procedure and results with having the vacuum truck to dispose of additional water.
There have been attempts over the years to try to use various damper or gate type systems, such as the aluminum slide and weir gates manufactured by Northcoast Valve & Gate Inc., and slide gates manufactured by Halliday Products Inc. The common problem with damper or gate systems used in the prior art is that they are either difficult to install and use, or they leak badly. Additionally, these gates are too heavy and cumbersome for a single person to unlock and lift, and instead usually require two or more persons to operate which adds extra expenses and time.
Thus, the need exists for solutions to the above problems with the prior art.
SUMMARY OF THE INVENTION
A primary objective of the present invention is to provide devices, apparatus, systems and methods of using a damper system to isolate waterways, such as storm water treatment systems, manmade ponds and pools, natural lakes, ponds, actuaries and other water ways from unwanted water inflow so that gates can be easily opened when needed.
A secondary objective of the present invention is to provide devices, apparatus, systems and methods of using a damper system in a storm water treatment systems, manmade ponds and pools, natural lakes, ponds, actuaries and other water ways, that will reduce service treatment time and increase the effectiveness of services which will improve the removal efficiency of treatment systems and reduce servicing costs.
A third objective of the present invention is to provide devices, apparatus, systems and methods of using a damper system in a storm water treatment systems, manmade ponds and pools, natural lakes, ponds, actuaries and other water ways, that is easy to install and use, and will not leak.
A fourth objective of the present invention is to provide devices, apparatus, systems and methods of using a damper system in a storm water treatment systems, manmade ponds and pools, natural lakes, ponds, actuaries and other water ways, that can be used by a single person to lock and unlock.
A fifth objective of the present invention is to provide devices, apparatus, systems and methods of using a damper system in a storm water treatment systems, manmade ponds and pools, natural lakes, ponds, actuaries and other water ways, using wheels that dramatically reduce friction to allow the door to be lifted and removed by a single person.
The novel damper system can include a track that attaches to the inside wall of a separator that is used in storm water treatment systems, manmade ponds and pools, natural lakes, ponds, actuaries and other water ways, with a damper panel that rotatably slides in place.
The external housing of the stormwater vault or treatment structure is commonly made of concrete, fiberglass, or plastic. The damper system track can be installed so that it makes a kind of frame around the inflow and/or outflow pipes and is attached to the inside surface of the treatment structure. A track system can be ideally sized to accommodate the damper panel.
The damper panel can be made of metal, fiberglass, or plastic, combinations thereof, and the like, can have a cam system mechanism along the vertical edges of the panel on one side. On the other side of the panel a rubber seal is continuous along the edge of the panel, going down one side, then across the bottom, and then up the other side. When the damper panel is lowered into the track system to block the pipe it is very loose and does not bind along the track system. When the cams are rotated the mechanism can then force the panel to wedge into the track and compress the rubber seal along the inside surface of the track. Once the cams have wedged the damper panel in place and the rubber seal is compressed against the track, the panel is locked in place and it will not leak water from the pipe into the stormwater vault.
The cams can be rotated to either lock the damper panel in place or release the damper panel. The cams can be either rotated by a lever attached to the top of the cam system, or a wrench, or other tools such as but not limited to pliers, pipes, and the like. The wrench can be either hand held or socket attached to the end of a hand held pole. The advantage of attaching the socket to the end of a long pole is that a person does not need to enter the vault to rotate the cams.
The damper panel can have a special lifting point attachment that allows the panel to be lowered into the track system without having to enter the vault. The lifting point would have a slot that would sized to receive an approximately 1″ diameter ball such as a metal sphere attached to the end of a thin rod, and the rod would be attached to a hand held pole. The damper panel would hang vertically on the end of the hand held pole and the geometry of the sphere in the slot would allow the damper panel to freely articulate on the end of the pole without binding. By this method the damper panel can be easily lowered into the vault and placed into the damper track.
A plurality of wheels on each side of the panel assembly can allow for the panel assembly to easily ride up and down in the tracks.
The separate rotatable cams in each of the tracks can be replaced by single elongated cams that can have paddle or wedge shapes. Alternatively, the invention can use removable wedges that when driven into place compress and water seal the damper panel in place.
A preferred embodiment of a damper system for storm water treatment vault structures, can include a frame attached to an inner wall of a vault structure, the frame having an opening therethrough, tracks attached to the frame about the opening, a door having wheels along outer side edges, the wheels of the door being slidably received within the tracks, the door having an open position for allowing water to flow into the vault structure and a closed position for preventing water from passing into the vault structure, and moveable members along one side face of the door for pushing the door against portions of the track to seal the door against water intrusion.
The moveable members can include rotatable cams along perimeters of side edges of the door, the cams having an unlocked position where the door is loosely seated in the tracks and a locked position where the door is pushed against one side of the tracks, wherein the locked position prevents water from passing about edges of the door.
The removable tool can be a hand wrench for rotating the cams from the unlocked to the locked position. The removable tool can be a socket wrench for rotating the cams from the unlocked to the locked position.
The moveable members can be a single elongated rotatable cam on each side edge of the door. Alternatively, the moveable members can include a plurality of rotatable cams on each side edge of the door.
An elongated seal members between perimeter edges of the door and the one side of the track, can be used wherein the cams in the locked position causes the door to compress the elongated sealing members against the one side of the track so that water is sealed and prevented from entering about the edges of the door.
A handle can be attached to the door for raising and lowering the door. An elongated tool having an end portion can attach to and detach to the handle. The elongated tool can have a hook end, wherein lifting the handle raises the door from the tracks, and allows the storm water to enter into the vault structure.
A preferred method of locking and unlocking slidable doors in a storm water vault structure in order to service the vault structure, can include the steps of providing a door having wheels on sides of the door, sliding the wheels within tracks against an inlet wall of a storm water structure, providing the sides of the door with rotatable cams, locking the door in the tracks by rotating the rotatable cams so that the cams push one side of the door against a portion of the tracks, and unlocking the door rotating the rotatable cams in a counter direction so that the door against loosely sits in the tracks.
The method can further include the steps of providing elongated gasket members along side edges of the door, and sealing the door against the tracks by the locking of the door which compresses the elongated gasket members.
The method can further include the step of removing storm water in the vault structure after the door is sealed in place with as vacuum truck before physically servicing the interior of the vault structure.
The method can further include the step of selectively locking the door in a lower position wherein water flows over the door. The method can further include the step of selectively locking the door in an upper position wherein water flows under the door.
Another embodiment of the damper system for storm water treatment vault structures, can include a frame attached to an inner wall of a vault structure, the frame having an opening therethrough, tracks attached to the frame about the opening, a slidable door having outer side edges being slidably received within the tracks, the slidable door having a lower position for allowing water to flow over the door into the vault structure and an upper position for allowing the water to flow under the door into the vault structure, and the door having closed position for preventing the water from flowing into the vault, and a member for raising and lowering and closing the slidable door.
The system can include rollers on each of the side edges of the slidable door. The system can include cams for locking the door into different height positions within the tracks.
The slidable door can include a door in door version with a primary door that slides in tracks, and a secondary door smaller than the primary door, the secondary door slides up and down in tracks on the primary door.
Further objects and advantages of this invention will be apparent from the following detailed description of the presently preferred embodiments which are illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a top perspective view of a prior art concrete storm water handling vault.
FIG. 2 is a perspective cut-away sectional view of a vault with novel damper system ready to install.
FIG. 3 shows the damper system installed in the vault shutting off water flow.
FIG. 4 shows the damper panel assembly removed from the damper frame allowing water to flow.
FIG. 5 is a front view of the damper system of FIG. 2 .
FIG. 6 is a side view of the damper system of FIG. 5 .
FIG. 7 is a front perspective view of the damper system of FIG. 5 .
FIG. 8 is a rear perspective view of the damper system of FIG. 5 .
FIG. 9 is a front perspective view of the damper system of FIG. 5 with damper panel removed.
FIG. 10 is a rear perspective view of the damper system of FIG. 5 with damper panel removed.
FIG. 11 is a rear view of the damper panel used in the damper system of FIG. 5 .
FIG. 12 is a side view of the damper panel of FIG. 11 .
FIG. 13 is a front view of damper panel of FIG. 11 .
FIG. 14 is a perspective enlarged view of the panel locking system of the damper system of FIG. 5 in a locked configuration.
FIG. 15 is a perspective enlarged view of the panel locking system of FIG. 14 in an unlocked configuration.
FIG. 16 is a top view of the panel locking system of FIG. 14 along arrows 16 Y in a locked configuration.
FIG. 17 is a top view of the panel locking system of FIG. 15 along arrows 17 Y in an unlocked configuration.
FIG. 18 is a top view of the panel locking system of FIG. 14 along arrows 18 Y showing an open-ended wrench being used to lock the panel into the panel frame.
FIG. 19 is a top view of the panel locking system of FIG. 18 along arrows 19 Y showing open-ended wrench being used to unlock the panel from the panel frame.
FIG. 20 is a bottom view of the panel locking system of FIG. 14 along arrows 20 Y showing the stop-block arresting the counter-clockwise motion of the cam.
FIG. 21 is a bottom view of the panel locking system of FIG. 20 along arrows 21 Y showing the stop-block arresting the clockwise motion of the cam.
FIG. 22 shows an upper view of the damper panel system in water, with a remote socket wrench tool ready to engage the damper release hex.
FIG. 22A is an enlarged partial view of FIG. 22 showing the socket on the tool ready to engage the damper release hex.
FIG. 23 shows an upper view of the damper panel system in water with a remote socket wrench tool engaged to damper release hex.
FIG. 23A is an enlarged partial view of FIG. 23 showing the socket on the tool ready to unlock the damper release hex.
FIG. 24 shows a perspective view of a remote panel lifting hook tool preparing to engage the lift handle on the damper panel that is attached the damper panel system.
FIG. 25 is another view of FIG. 24 showing the remote panel lifting hook tool lifting the damper panel from the panel frame.
FIG. 26 is a perspective view of a person grasping the damping panel handle preparing to lift the panel from the frame.
FIG. 27 is another view of FIG. 26 showing the person lifting the damping panel from the frame.
FIG. 28 is a perspective view of a hook tool used in FIG. 24 .
FIG. 28A is an enlarged view of the hook end and ball on the hook tool of FIG. 28 .
FIG. 29 is a side view of hook tool of FIG. 28 .
FIG. 29A is an enlarged view of the hook end and ball on the hook tool of FIG. 29 .
FIG. 30 is a side view of the remote socket wrench tool-used in FIGS. 22 , 22 A, 23 and 23 A.
FIG. 30A is an enlarged view of the socket part of the tool of FIG. 30 .
FIG. 31 is a perspective view of the remote socket wrench tool of FIG. 30 .
FIG. 31A is an enlarged view of the socket part of the tool of FIG. 31 .
FIG. 32 is a perspective cut-away view of a “flow-over” door system shown with the door down.
FIG. 33 is a perspective cut-away view of the flow-over door system of FIG. 32 with the door pulled half way up in the door tracks.
FIG. 34 is a perspective cut-away view of the flow-over door system of FIG. 33 with the door pulled up fully
FIG. 35 is a perspective cut-away view of a “door-in-a-door” system with the primary flow through door removed.
FIG. 36 is a perspective cut-away view of the door-in-a-door system of FIG. 35 with the primary door installed half way.
FIG. 37 is a perspective cut-away view of the door-in-a-door system of FIG. 36 with the primary door fully installed.
FIG. 38 is a perspective cut-away view of the door-in-a-door system of FIG. 37 with secondary smaller door installed half way.
FIG. 39 is a perspective cut-away view of the door-in-a-door system of FIG. 38 with secondary door fully installed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its applications to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
A list of components will now be described.
10 . Concrete storm water handling vault. 20 . Storm water inflow. 30 . Storm water outflow. 40 . Vault wall. 40 A. Inner wall 50 . Novel damper system with wheels. 60 . Vault inlet. 70 . Vault outlet pipe. 80 . Composite frame. 90 . Novel panel assembly with wheels. 95 . Grooves in side edges of panel 92 . 100 . Panel lift handle. 110 . Front wall of composite frame. 112 / 114 . Parallel Tracks (left channel and right channel) 116 . Lower channel of front wall. 120 . Damper panel release hex. 130 . Frame mounting holes. 140 . Frame mounting flange. 150 . Frame gussets (such as angled strengthening members) 160 . Back wall of composite frame. 170 . Articulating panel support wheel. 180 . Panel. 190 . Foam rubber panel seal/gasket members 200 . Lock release rod. 210 . Damper panel stiffener brace. 220 . Damper panel cam-lock. 230 . Wheel toggle locking bar. 240 . Panel mounted hinge upon which wheel brackets are affixed allow wheels to articulate. 250 . Lock release rod mount block. 260 . Wheel mount bracket. 270 . Stop block prevents cam over-travel in locked or unlocked configuration. 280 . Socket Wrench Tool to lock and unlock panel. 285 . Hex head 289 . Hand wrench 290 . Panel cutout to clear support wheel. 300 . Water pressure. 310 . Cam-lock mounting bar welded to lock release rod. 320 . Storm water in vault. 330 . wrench tool for remote unlocking of panel assembly. 340 . Socket for engaging panel release hex. 350 . Universal joint for all-angle operation of remote socket wrench tool. 360 . Hook tool for remote lifting of panel assembly. 370 . Person. 380 . Telescoping tube handle. 390 . Ball on hook end to prevent panel lift handle slip. 400 . Reinforced lift hook.
The subject invention is a Continuation-In-Part of U.S. patent application Ser. No. 12/533,806 filed Jul. 31, 2009, entitled: Box Service Panel Door and Equalizer, which is incorporated by reference.
FIG. 1 is a top perspective view of prior art type concrete storm water handling vault 10 that can have four vault walls 40 with storm water 20 inflow coming in through an inlet opening 60 into the vault 10 and eventually flow out 30 through an outlet pipe 70 . The external housing of the stormwater vault 10 or treatment structure is commonly made of concrete, fiberglass, or plastic.
FIG. 2 is a cut-away perspective section view of the FIG. 1 vault 10 with novel damper system 50 invention ready to be installed to an inner wall 40 A over the inlet port 60 to the vault 10 . FIG. 3 shows the damper system 50 installed in the vault 10 shutting off water flow with storm water 320 within the vault. FIG. 4 shows the damper panel assembly 90 removed from the damper frame 80 allowing water to flow 20 to flow through vault inlet 60 .
The novel damper system 50 can include a composite frame assembly 80 that can attach to the inner surface of the wall 40 about the inlet port 60 by fasteners, such as but not limited to bolts, screws, and the like. Once installed, a damper panel assembly with wheels 90 can slide into parallel tracks 112 , 114 in the frame assembly 80 to close off the inlet port 60 .
FIG. 5 is a front view of the damper system 50 of FIG. 2 . FIG. 6 is a side view of the damper system 50 of FIG. 5 . FIG. 7 is a front perspective view of the damper system 50 of FIG. 5 . FIG. 8 is a rear perspective view of the damper system 50 of FIG. 5 .
The damper panel 90 can be made from metal such as but not limited to aluminum, galvanized metal, stainless steel, fiberglass, plastic or combinations thereof.
Referring to FIGS. 5-8 , frame mounting holes 130 through the U-shaped frame mounted flange 140 of the frame assembly 80 allow for the fasteners to be used to attach the frame assembly 80 to the inner wall 40 A of the vault 10 . Frame gussets, such as lower angled strengthening members 150 and side angled strengthening members 86 support the U-shaped flange to the tracks 112 , 114 . The damper panel 90 can slide along the parallel tracks 112 , 114 and sit against a lower channel 116 . Across the top of the damper panel 90 is a panel lift handle 100 , that can be fastened along bent outer edges by fasteners, such as screws and bolts. The damper panel release hex 120 whose operation of which will be described in greater detail later in reference to FIGS. 14 , 15 , 18 , 19 .
FIG. 9 is a front perspective view of the damper system 50 of FIG. 5 with damper panel 90 removed from the frame 80 . FIG. 10 is a rear perspective view of the damper system 50 of FIG. 5 with damper panel 90 removed from the frame 80 . FIG. 11 is a rear view of the damper panel 90 used in the damper system 50 of FIG. 5 . FIG. 12 is a side view of the damper panel of 90 FIG. 11 , and FIG. 13 is a front view of damper panel 90 of FIG. 11 .
Referring to FIGS. 9-13 , the novel frame 80 includes a back wall 160 of the frame behind the front wall 110 . The panel assembly 90 includes a generally rectangular panel 180 , having a plurality of articulating panel support wheels along both the right and side edges of the panel 180 , with each of the wheels positioned within grooves 95 in the side edges of the panel 180 . A preferred embodiment has three wheels 170 each on wheel mount brackets 260 along each of the right and left side edges of the panel 180 that are moveable by wheel toggle locking bars 230 . Panel mounted hinges 240 are located along both the right and left sides of the panel 180 on which the wheel brackets 260 are affixed and which allow the wheels 170 to articulate.
A foam rubber panel seal 190 having a continuous U shaped configuration can be located on the rear side of the panel 180 , and in operation can provide a waterseal between panel 180 and the rear wall 160 of the frame 80 . Handle 100 can have a base attached by fasteners, such as screws, bolts, and rivets to a damper panel stiffener brace 210 .
A lock release rod 200 can have an upper end with a damper panel release hex 120 that allows the rod 200 to be rotated clockwise or counterclockwise. The rod 200 can pass through three lock release rod mount blocks 250 that are arranged on both the left and right sides of the panel 180 . A pair of damper panel cam-locks 220 can be arranged on both the left and right sides of the panel and can be controlled by the rotatable rod 200 . Stop blocks 270 can be used to prevent cam over-travel in locked or unlocked configurations, and which will be described in further detail below.
As discussed the frame 80 has a left channel 112 , and right channel 114 and lower channel 116 that are formed between a front wall 110 and a rear wall 160 . Angled frame gussets 150 add strength support to the channels 112 , 114 , 116 , and holes 130 are used for fasteners to mount the frame 80 to an inner vault wall 40 A.
FIG. 14 is a perspective enlarged view of the panel locking system of the damper system 50 of FIG. 5 in a locked configuration. FIG. 15 is a perspective enlarged view of the panel locking system of FIG. 14 in an unlocked configuration with the wrench 280 rotated counter-clockwise. FIG. 16 is a top view of the panel locking system of FIG. 14 along arrows 16 Y in a locked configuration. FIG. 17 is a top view of the panel locking system of FIG. 15 along arrows 17 Y in an unlocked configuration. FIG. 18 is a top view of the panel locking system of FIG. 14 along arrows 18 Y showing an open-ended wrench 280 being used to lock the panel into the panel frame. FIG. 19 is a top view of the panel locking system of FIG. 18 along arrows 19 Y showing open-ended wrench 280 being used to unlock the panel 180 from the panel frame 80 . FIG. 20 is a bottom view of the panel locking system of FIG. 14 along arrows 20 Y showing the stop-block 270 arresting the counter-clockwise motion of the cam 220 . FIG. 21 is a bottom view of the panel locking system of FIG. 20 along arrows 21 Y showing the stop-block 270 arresting the clockwise motion of the cam 220 .
Referring to FIGS. 14-21 , the socket wrench tool 280 can have a socket 285 that fits about damper panel release hex 120 (such as a hex head of a bolt).
FIGS. 14 and 16 show the panel in a lock position with the cam-lock 220 abutting against the front wall 110 of the composite frame 80 , and the foam rubber panel seal 190 compressed between the panel 180 and the back wall 160 of the composite frame 80 . The articulating support wheel(s) 170 are shown articulated (angled) by the panel mounting hinge 240 . Water pressure 300 is shown by an arrow pressing against and exposed surface of the panel 180 .
As shown in FIGS. 15 , and 17 , the socket wrench tool 280 is rotated counter-clockwise on the hex 120 , the lock release rod 200 also rotates counter-clockwise rotating the damper panel cam-lock 220 away from front wall 110 of the composite frame 80 . The panel 180 becomes spaced apart from the back wall 160 of the composite frame 80 allowing the foam rubber panel seal 190 to expand by being separate from back wall 160 .
FIGS. 18 and 19 show a hand wrench 289 attached to damper panel release hex 120 that can be used instead of the socket wrench tool 280 to lock (rotating clockwise) and unlock (rotating counter-clockwise).
FIG. 20 is a bottom view of the panel locking system of FIG. 14 along arrows 20 Y showing the stop-block 270 arresting the counter-clockwise motion of the cam 220 with the cam-lock mounting bar 310 welded to the lock release rod 200 . FIG. 21 is a bottom view of the panel locking system of FIG. 20 along arrows 21 Y showing the stop-block 270 arresting the clockwise motion of the cam 220 with the cam-lock mounting bar 310 welded to the lock release rod 200 . In FIG. 21 , the outer surface of the wheel(s) 170 extends through the panel cutout(s) 290 to clear the support wheel(s) 170 .
FIG. 30 is a side view of the elongated handle remote socket wrench tool 330 used in FIGS. 22 , 22 A, 23 and 23 A. FIG. 30A is an enlarged view of the socket part 340 of the tool 330 of FIG. 30 . FIG. 31 is a perspective view of the remote socket wrench tool 330 of FIG. 30 . FIG. 31A is an enlarged view of the socket part 380 of the tool 330 of FIG. 31 . The elongated handle remote socket wrench tool 330 can have a telescoping tube handle with cylindrical type parts that slide in and out of each other extending and reducing the length of the handle portion of the tool 330 . A universal joint 350 between the handle portion 380 and the socket 340 allows for all-angle operation and versatility and maneuverability of the remote socket wrench tool 330 .
FIG. 22 shows an upper view of the damper panel system 50 in water, with a remote elongated handle socket wrench tool 330 (of FIGS. 30-31A ) ready to engage the damper release hex 120 . A universal joint 350 on the elongated tool 330 allows for all angle operation of the elongated remote socket wrench tool 330 . FIG. 22A is an enlarged partial view of FIG. 22 showing the socket 340 on the tool 330 ready to engage the damper release hex 120 . FIG. 23 shows an upper view of the damper panel system 50 in water 320 with the elongated remote socket wrench tool 330 engaged to damper release hex 120 . Clockwise turn of tool unlocks panel 180 from panel frame 80 . Counter-clockwise locks the panel 180 to the frame 80 FIG. 23A is an enlarged partial view of FIG. 23 shows the socket 340 on the tool 330 ready to unlock the damper release hex 120 .
FIG. 28 is a perspective view of a hook tool 360 used in FIG. 24 . FIG. 28A is an enlarged view of the hook end 400 and ball 390 on the hook tool 360 of FIG. 28 . FIG. 29 is a side view of hook tool 360 of FIG. 28 . FIG. 29A is an enlarged view of the hook end 400 and ball 390 on the hook tool 360 of FIG. 29 .
FIG. 24 shows a perspective view of a remote panel lifting hook tool 360 (shown in FIGS. 28-29A ) preparing to engage the lift handle 100 on the damper panel assembly 90 that is attached the damper panel system 80 after the panel assembly is in an unlocked position. The ball 390 on the hook end 400 is inserted through the extended handle 100 hooking the handle 100 . FIG. 25 is another view of FIG. 24 showing the remote panel lifting hook tool 360 lifting the damper panel assembly 90 from the panel frame 80 . A user (not shown) can raise the hook tool 360 that has the hook end 400 with ball 390 hooked about the handle 100 and clearly lift the panel assembly 90 from the frame and allow storm water inflow 20 into the stormwater 320 inside of the vault.
FIG. 26 is a perspective view of a person 370 grasping the damping panel handle 100 preparing to lift the panel assembly 90 from the frame 80 , after the panel assembly is in an unlocked position. FIG. 27 is another view of FIG. 26 showing the person 370 lifting the damping panel assembly 90 from the frame 80 .
Although the figures show the damper panel assembly with frame mounted on the wall of a vault, the invention can be used on other types of walls, such as on dams, and the like.
The foam rubber panel seal 190 can be an elongated seal member, and can be a gasket member such as but not limited to one having a C or E or U type channel that compresses. The seal can also include resilient and/or elastomeric type members, and the seal can be an inflatable bladder type tube(s), and the like. Additionally, the seal 190 can be placed along the bottom edge of the panel as well as the left and right sides of the panel. In a preferred embodiment, the seal member is placed on the opposite side of the panel from the inlet port to the vault or structure.
Although preferred types of lifting tools are described, the invention can use other types of tools for lifting the panel assembly, such as but not limited to using a manhole hook tool, and the like.
While the handle 100 is shown as rectangular, the handle can have other shapes such as triangular, arc shaped, and the like, and can have a catch portion such as an indented or cut-out or lip edge, that can also be snagged or hooked to lift the panel assembly.
Although the invention refers to wrenches, the invention can work with lever arms that are fixably attached to the tops of the cam bars, or are removably attached as needed. Although the invention shows separate rotatable cams in the tracks, a single elongated cam can be used on each side of the panel that can have paddle or wedge shapes. Alternatively, the invention can use removable wedges that when driven into place compress and water seal the damper panel in place.
The invention can incorporate embodiments of the rotating wheels on the doors moving up and down in a track, where the track is in a fixed wall. Alternatively, the invention can have a sliding main primary door, and a secondary door that slides up and down relative to the primary door. The embodiments can have flow over versions so that water can overflow over a sliding door into a vault. Likewise, the embodiments can flow under versions where water flows under a slidable door into a vault. Either or both the primary and secondary doors can slide up in down within tracks with or without rollers and wheels to ease the sliding action of the respective doors.
FIG. 32 is a perspective cut-away view 510 of a “flow-over” door system shown with the door 90 down. The system is at maximum flow capacity where arrows can represent an overflow into a vault, FIG. 33 is a perspective cut-away view 520 of flow-over door system of FIG. 32 with the door 90 pulled half way up in the door tracks in frame 80 . The flow-over capacity is cut by half. Further choices of position are possible to adjust flow. The invention can allow for the door to be selectively fixed by the user in different height positions in the tracks. FIG. 34 is a perspective cut-away view 530 of flow-over door system of FIG. 33 with the door 90 pulled up fully Here, the flow is completely cut off from entering into the vault.
FIG. 35 is a perspective cut-away view 540 of “door-in-a-door” system with the primary flow through the opening in the wall with the main (primary) door 90 B removed. Here, the system is at maximum flow capacity. FIG. 36 is a perspective cut-away view 550 of the door-in-a-door system of FIG. 35 with the primary door 90 B installed half way. System is at about half flow-under capacity. Further choices of position are possible to adjust flow. Similar to the previous embodiment, the primary door 90 B can be selectively locked in different height positions within the tracks as needed.
FIG. 37 is a perspective cut-away view 560 of the door-in-a-door system of FIG. 36 with the primary door 90 B fully installed, and the smaller secondary smaller door 90 D removed from tracks 90 C. Here, the system is at maximum flow-over capacity. FIG. 38 is a perspective cut-away 570 view of door-in-a-door system of FIG. 37 with the secondary smaller door 90 D installed half way on tracks 90 C. Here, the system is at about half flow-under (secondary) capacity. Further choices of position for the secondary door 90 D are possible to adjust flow-over capacity. Similar to the previous embodiment, the secondary door can be selectively locked in different height positions within the tracks as needed. FIG. 39 is a perspective cut-away view 580 of the door-in-a-door system of FIG. 38 with the secondary door 90 D fully installed. Here, the flow is completely being cut off.
Although the invention is described for use with storm water treatment vaults and structures, the invention can have other applications, such as but not limited to being used in dam type applications, and the like for ponds, lakes, pools, waterfalls, and the like.
While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended. | Systems, devices, apparatus, and methods of locking and unlocking a door that is slidable by articulating wheels in tracks, over an entry port to a storm water structure. Locking the door can be accomplished by rotating bolt heads that are attached to cams. Rotating the heads causes cams to press the door against the tracks. Sealing strips can be compressed between door edges and the track to prevent water from passing around the door. A vacuum truck can remove water and debris from the vault/structure. Other versions allow doors to move downward to allow water to overflow the door. The door can slide upward so water can flow underneath. A door in door version has a secondary door slide up and down in tracks in a main door. | 4 |
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