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This application is a division of application Ser. No. 09/532,721, filed Mar. 22, 2000, now U.S. Pat. No. 6,469,926.
This invention was made with Government support under Agreement No. MDA972-96-3-0016 awarded by DARPA. The Government has certain rights in the invention.
FIELD OF THE INVENTION
The present invention relates to magnetic elements for information storage and/or sensing and a fabricating method thereof, and more particularly, to a method of fabricating and thus defining the magnetic element to improve the magnetoresistance ratio.
BACKGROUND OF THE INVENTION
This application is related to a co-pending application that bears Motorola docket number CR97-133 and U.S. Ser. No. 09/144,686, entitled “MAGNETIC RANDOM ACCESS MEMORY AND FABRICATING METHOD THEREOF,” filed on Aug. 31, 1998, assigned to the same assignee and incorporated herein by this reference, co-pending application that bears Motorola docket number CR 97-158 and U.S. Ser. No. 08/986,764, entitled “PROCESS OF PATTERNING MAGNETIC FILMS” filed on Dec. 8, 1997, assigned to the same assignee and incorporated herein by this reference and issued U.S. Pat. No. 5,768,181, entitled “MAGNETIC DEVICE HAVING MULTI-LAYER WITH INSULATING AND CONDUCTIVE LAYERS”, issued Jun. 16, 1998, assigned to the same assignee and incorporated herein by.
Typically, a magnetic element, such as a magnetic memory element, has a structure that includes ferromagnetic layers separated by a non-magnetic layer. Information is stored as directions of magnetization vectors in magnetic layers. Magnetic vectors in one magnetic layer, for instance, are magnetically fixed or pinned, while the magnetization direction of the other magnetic layer is free to switch between the same and opposite directions that are called “parallel” and “anti-parallel” states, respectively. In response to parallel and anti-parallel states, the magnetic memory element represents two different resistances. The resistance has minimum and maximum values when the magnetization vectors of the two magnetic layers point in substantially the same and opposite directions, respectively. Accordingly, a detection of change in resistance allows a device, such as an MRAM device, to provide information stored in the magnetic memory element. The difference between the minimum and maximum resistance values, divided by the minimum resistance is known as the magnetoresistance ratio (MR).
An MRAM device integrates magnetic elements, more particularly magnetic memory elements, and other circuits, for example, a control circuit for magnetic memory elements, comparators for detecting states in a magnetic memory element, input/output circuits, etc. These circuits are fabricated in the process of CMOS (complementary metal-oxide semiconductor) technology in order to lower the power consumption of the device.
Magnetic elements structurally include very thin layers, some of which are tens of angstroms thick. The manufacturability throughput and performance of the magnetic element is conditioned upon the magnetic structure utilized and its complexity. Accordingly, it is necessary to make a magnetic device in which a simple structure is sought. A magnetic element structure in which including are fewer layers than the standard magnetic element and less targets, is sought. In addition, it is sought to build a device in which a centered R—H(I) loop does not depend on the precise overly for each of the millions to billions of bits.
During typical magnetic element fabrication, such as MRAM element fabrication, metal films are grown by sputter deposition, evaporation, or epitaxy techniques. One such magnetic element structure includes a substrate, a base electrode multilayer stack, a synthetic antiferromagnetic (SAF) structure, an insulating tunnel barrier layer, and a top electrode stack. The base electrode layer stack is formed on the substrate and includes a first seed layer deposited on the substrate, a template ferromagnetic layer formed on the seed layer, a layer of an antiferromagnetic material on the template layer and a pinned ferromagnetic layer formed on and exchange coupled with the underlying antiferromagnetic layer. The ferromagnetic layer is called the pinned layer because its magnetic moment (magnetization direction) is prevented from rotation in the presence of an applied magnetic field. The SAF structure includes a pinned ferromagnetic layer, and a fixed ferromagnetic layer, separated by a layer of ruthenium, or the like. The top electrode stack includes a free ferromagnetic layer and a protective layer formed on the free layer. The magnetic moment of the free ferromagnetic layer is not pinned by exchange coupling, and is thus free to rotate in the presence of applied magnetic fields. As described, this type of magnetic element structure includes a very complex arrangement of layers and as such is not amenable to high throughput.
An alternative structure includes, a magnetic element material stack which includes three magnetic layers separated by one tunnel barrier and one conductive spacer, such as TaN y . The middle magnetic layer is formed so that it is free to rotate or change direction, while the top and bottom magnetic layers are locked in an antiparallel arrangement or direction due to lowered energy from flux closure at the ends. During operation, the structure will have different resistances depending on which of the two directions the middle magnetic layer points its magnetization. In order to achieve a magnetic element which includes a better signal, or an improved magnetoresistance ratio, it is desirable to includes dual tunnel barrier layers. Yet, it has been found that this structure will fail if a tunnel barrier is utilized in the place of the conductive spacer.
Accordingly, it is a purpose of the present invention to provide an improved magnetic element with an improved magnetoresistance ratio.
It is another purpose of the present invention to provide an improved magnetic element that includes a higher MR % or signal, and less voltage dependence.
It is a still further purpose of the present invention to provide a method of forming a magnetic element with an improved magnetoresistance ratio.
It is still a further purpose of the present invention to provide a method of forming a magnetic element with an improved magnetoresistance ratio which is amenable to high throughput manufacturing.
SUMMARY OF THE INVENTION
These needs and others are substantially met through provision of a magnetic element including a first magnetic layer, comprised of a pinned ferromagnetic material, a second magnetic layer, that is free to rotate, a third magnetic layer, comprised of a pinned ferromagnetic material, and two (2) tunnel barrier layers. The structure is defined as including two (2) tunnel barrier layers in which one tunnel barrier layer is normal and one is reversed, or a structure in which the two tunnel barrier layers are of the same type and the structure further includes a SAF structure to allow for same sign changing magnetoresistance ratios across both tunnel barriers. A spacer layer is generally included when the magnetic element includes the SAF structure. The magnetic element further includes a metal lead. The metal lead, the plurality of magnetic layers, the plurality of tunnel barrier layers, and the spacer layer being formed on a substrate material, such as a dielectric. Additionally disclosed is a method of fabricating the magnetic element with an improved magnetoresistance ratio.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 illustrate in cross-sectional views, first and second embodiments of a magnetic element with an improved magnetoresistance ratio according to the present invention; and
FIGS. 3 and 4 illustrate in cross-sectional views, second and third embodiments of a magnetic element with an improved magnetoresistance ratio according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
During the course of this description, like numbers are used to identify like elements according to the different figures that illustrate the invention. FIGS. 1 and 2 illustrate in cross-sectional views a first and second embodiment of a magnetic element according to the present invention. More particularly, illustrated in FIG. 1, is a first embodiment of a fully patterned magnetic element 10 . Magnetic element 10 structurally includes a bottom pinned magnetic layer 12 , a bottom tunnel barrier layer 14 , a free magnetic layer 16 , a top tunnel barrier layer 18 , and a top pinned magnetic layer 20 . Bottom pinned magnetic layer 12 , free magnetic layer 16 and top pinned magnetic layer 20 include ferromagnetic layers. Bottom magnetic layer 12 is formed on a diffusion barrier layer 22 which is formed on a metal lead 24 . Diffusion barrier layer 22 is typically formed of tantalum nitride (TaN), and aids in the thermal stability of magnetic element 10 . Metal lead 24 is typically formed on some type of dielectric material (not shown).
Bottom and top pinned ferromagnetic layers 12 and 20 are described as pinned, or fixed, in that their magnetic moment is prevented from rotation in the presence of an applied magnetic field. Ferromagnetic layers 12 , 16 and 20 are typically formed of alloys of one or more of the following: nickel (Ni), iron (Fe), and cobalt (Co) and each include a top surface 13 , 17 , and 21 , respectively, and a bottom surface 11 , 15 and 19 , respectively. Magnetic layer 16 is described as a free ferromagnetic layer. Accordingly, the magnetic moment of free ferromagnetic layer 16 is not fixed, or pinned, by exchange coupling or magneto static coupling through flux closure, and is free to rotate in the presence of an applied magnetic field. Free ferromagnetic layer 16 is formed co-linear with pinned magnetic layers 12 and 20 and of alloys of one or more of the following: nickel (Ni), iron (Fe), and cobalt (Co). Pinned ferromagnetic layers 12 and 20 are described as having a thickness within a range of 5-5000 Å. Free ferromagnetic layer 16 is described as having a thickness generally less than 500 Å. A second diffusion barrier layer 26 is formed on an uppermost surface 21 of top pinned magnetic layer 20 . A metal lead 28 is formed on a surface of second diffusion barrier layer 26 .
In this particular embodiment, bottom tunnel barrier layer 14 is formed of tantalum (Ta) and oxygen (O). More particularly, bottom tunnel barrier layer 14 is formed having a general formula of TaO Y , where 1<Y<2.5. Top tunnel barrier layer 18 is formed of oxidized aluminum (Al), generally having the formula AlO x , where x≦1.5.
In this particular embodiment, top tunnel barrier layer 18 is described as being a normal tunnel barrier, such that the magnetic tunnel junction has a maximum resistance (R) for anti-parallel aligned magnetic electrodes, and a minimum resistance (R) for parallel aligned magnetic electrodes. More specifically, when free ferromagnetic layer 16 is aligned parallel with bottom pinned magnetic layer 12 and anti-parallel to top pinned magnetic layer 20 , maximum resistance is achieved. When free ferromagnetic layer 16 is aligned anti-parallel with bottom pinned magnetic layer 12 and aligned parallel with top pinned ferromagnetic layer 20 , minimum resistance is achieved. Bottom tunnel barrier 14 is described as being a reverse tunnel barrier such that the magnetic tunnel junction has a maximum resistance (R) for parallel aligned magnetic electrodes, and a minimum resistance (R) for anti-parallel aligned magnetic electrodes. This type of structure provides for a higher magnetoresistance ratio (MR %) or stronger signal, and less voltage dependence. Typically the MR % decreases as the bias voltage increases. Accordingly, by including dual tunnel barrier layers, 16 and 18 , each will see one-half of the bias voltage, thus reducing the rate of drop in MR % as the bias voltage increases. In addition, only four (4) targets are needed, and no exact overlay is required. During operation, any topological positive coupling of the free magnetic layer 16 from bottom and top are canceled. This type of structure is designed for MRAM applications. During operation of magnetic element 10 , magnetic layers 12 and 20 will point and lock into an anti-parallel orientation due to magnetic flux closure and reduced magnetic energy, especially for smaller dimension memory cells for high density MRAM. Magnetic layer 16 remains free to switch directions, for use in memory devices, such as MRAM applications. Alternatively, in a larger dimension MRAM cell, pinning from an antiferromagnetic layer can be used to pin the bottom 12 and top 20 magnetic layers.
Illustrated in FIG. 2, is an alternative embodiment of a fully patterned magnetic element structure, referenced 10 ′, typical for use in read head and magnetic sensor applications. It should be noted that all components of the first embodiment that are similar to components of the second embodiment, are designated with similar numbers, having a prime added to indicate the different embodiment. Similar to the structure described with regard to FIG. 1, this structure includes a bottom pinned magnetic layer 12 ′, a bottom tunnel barrier layer 14 ′, a free magnetic layer 16 ′, a top tunnel barrier layer 18 ′, and a top pinned magnetic layer 20 ′. Bottom pinned magnetic layer 12 ′, free magnetic layer 16 ′ and top pinned magnetic layer 20 ′ include ferromagnetic layers. Bottom magnetic layer 12 ′ is formed on a diffusion barrier layer 22 ′ which is formed on a metal lead 24 ′. Diffusion barrier layer 22 ′ is typically formed of tantalum nitride (TaN), and aids in the thermal stability of magnetic element 10 ′. Metal lead 24 ′ is typically formed on some type of dielectric material (not shown).
Bottom and top pinned ferromagnetic layers 12 ′ and 20 ′ are described as pinned, or fixed, in that their magnetic moment is prevented from rotation in the presence of an applied magnetic field. Ferromagnetic layers 12 ′, 16 ′ and 20 ′ are typically formed of alloys of one or more of the following: nickel (Ni), iron (Fe), and cobalt (Co) and each include a top surface 13 ′, 17 ′, and 21 ′, respectively, and a bottom surface 11 ′, 15 ′ and 19 ′, respectively. Magnetic layer 16 ′ is a free ferromagnetic layer. Accordingly, the magnetic moment of free ferromagnetic layer 16 ′ is not fixed, or pinned, by exchange coupling or magnetostatic coupling through flux closure, and is free to rotate in the presence of an applied magnetic field. Free ferromagnetic layer 16 ′ typically formed of alloys of one or more of the following: nickel (Ni), iron (Fe), and cobalt (Co). In contrast to the embodiment described in FIG. 1, in this particular embodiment, free ferromagnetic layer 16 ′ is perpendicularly aligned with respect to pinned ferromagnetic layers 12 ′ and 20 ′. Pinned ferromagnetic layers 12 ′ and 20 ′ are described as having a thickness within a range of 5-5000 Å. Free ferromagnetic layer 16 ′ is described as having a thickness generally less than 500 Å. A second diffusion barrier layer 26 ′ is formed on an uppermost surface 21 ′ of top pinned magnetic layer 20 ′. A metal lead 28 ′ is formed on a surface of second diffusion barrier layer 26 ′.
In this particular embodiment, bottom tunnel barrier layer 14 ′ is formed of tantalum (Ta) and oxygen (O). More particularly, bottom tunnel barrier layer 14 ′ is formed having a general formula of TaO Y , where 1<Y<2.5. Top tunnel barrier layer 18 ′ is formed of aluminum, generally having the formula AlO x , where x≦1.5.
Similar to the first described embodiment, top tunnel barrier layer 18 ′ is described as being a normal tunnel barrier, such that the magnetic tunnel junction has a maximum resistance (R) for anti-parallel aligned magnetic electrodes, and a minimum resistance (R) for parallel aligned magnetic electrodes. Tunnel barrier layer 14 ′ is described as being a reverse tunnel barrier, as previously described with respect to FIG. 1 . In contrast to the embodiment of FIG. 1, free ferromagnetic layer 16 ′ is perpendicularly aligned with bottom pinned magnetic layer 12 ′ and top pinned magnetic layer 20 ′. This type of structure provides for a higher magnetoresistance ratio (MR %) or stronger signal, and less voltage dependence. Typically the MR % decreases as the bias voltage increases. Similar to the embodiment of FIG. 1, by including dual tunnel barrier layers, 16 ′ and 18 ′, each will see one-half of the bias voltage, thus reducing the rate of drop in MR % as the bias voltage increases. In addition, only four (4) targets are needed, and no exact overlay is required. During operation, any topological positive coupling from bottom and top are canceled. This type of structure is designed for read head and magnetic sensor applications. During operation of magnetic element 10 ′, magnetic layers 12 ′ and 20 ′ will point and lock into an anti-parallel orientation due to magnetic flux closure and reduced magnetic energy for smaller dimension devices. Magnetic layer 16 ′ remains free to rotate perpendicularly to magnetic layers 12 ′ and 20 ′, and thus is suitable for use in read head or magnetic field sensors devices. Alternatively, in a larger dimension MRAM cell, pinning from an antiferromagnetic layer can be used to pin the bottom 12 ′ and top 20 ′ magnetic layers.
Referring now to FIG. 3, illustrated in simplified sectional view is a third embodiment of a magnetic element, according to the present invention. More particularly, illustrated is a magnetic element 30 including as a part thereof a synthetic antiferromagnetic (SAF) structure (discussed presently). Magnetic element 30 includes a bottom pinned magnetic layer 32 , a bottom tunnel barrier layer 34 , a SAF structure 36 , a top tunnel barrier layer 38 , and a top pinned magnetic layer 40 . Bottom pinned magnetic layer 32 , SAF structure 36 and top pinned magnetic layer 40 include ferromagnetic layers. Bottom magnetic layer 32 is formed on a diffusion barrier layer 42 which is formed on a metal lead 44 . Diffusion barrier layer 42 is typically formed of tantalum nitride (TaN), and aids in the thermal stability of magnetic element 30 . Metal lead 44 is typically formed on some type of dielectric material (not shown).
Bottom and top pinned ferromagnetic layers 32 and 40 are described as pinned, or fixed, in that their magnetic moment is prevented from rotation in the presence of an applied magnetic field. Ferromagnetic layers 32 and 40 are typically formed of alloys of one or more of the following: nickel (Ni), iron (Fe), and cobalt (Co) and each include a top surface 33 and 41 , respectively, and a bottom surface 31 and 39 , respectively.
SAF structure 36 includes a bottom free magnetic layer 46 , and a top free magnetic layer 48 formed antiparallel to each other, and co-linearly aligned relative to bottom pinned ferromagnetic layer 32 and top pinned ferromagnetic layer 40 at rest state for this embodiment. Bottom free magnetic layer 46 and top free magnetic layer 48 are separated by an exchange spacer layer 50 , typically formed of a layer of ruthenium (Ru), or the like. Antiparallel alignment between free magnetic layers 46 and 48 is achieved through an exchange spacer layer 50 which induces antiferromagnetic coupling between bottom free magnetic layer 46 and top free magnetic layer 48 , or through end magnetostatic coupling, or other means.
Free ferromagnetic layers 46 and 48 and pinned ferromagnetic layer 32 and 40 are typically formed of alloys of one or more of the following: nickel (Ni), iron (Fe), and cobalt (Co). Pinned ferromagnetic layers 32 and 40 are described as having a thickness within a range of 5-5000 Å. Free ferromagnetic layers 46 and 48 are described as each having a thickness generally less than 500 Å. A second diffusion barrier layer 52 is formed on an uppermost surface 41 of top pinned magnetic layer 40 . A metal lead 54 is formed on a surface of second diffusion barrier layer 52 .
In this particular embodiment, bottom tunnel barrier layer 34 and top tunnel barrier layer 38 are both formed of oxidized aluminum, generally having the formula AlO x , where x≦1.5. It is disclosed that in this embodiment, which includes SAF structure 36 , bottom tunnel barrier layer 34 and top tunnel barrier layer 38 are of the same type. More particularly, bottom tunnel barrier layer 34 and top tunnel barrier layer 38 are described as being normal tunnel barrier layers, such that the magnetic tunnel junction has a maximum resistance (R) for anti-parallel aligned magnetic electrodes, and a minimum resistance (R) for parallel aligned magnetic electrodes. More specifically, with free ferromagnetic layers 46 and 48 oppositely opposed, when bottom free magnetic layer 46 is anti-parallel to pinned magnetic layer 32 and top free magnetic layer 48 is anti-parallel to pinned magnetic layer 40 , maximum resistance is achieved. When bottom free magnetic layer 46 is parallel to pinned magnetic layer 32 and top free magnetic layer 48 is parallel to pinned magnetic layer 40 , minimum resistance is achieved. This magnetic element including a SAF structure provides for the inclusion of the same type of material for the formation of tunnel barrier layers 34 and 38 , and for a higher magnetoresistance ratio (MR %) or stronger signal, and less voltage dependence. Typically the MR % decreases as the bias voltage increases. Accordingly, by including dual tunnel barrier layers, 34 and 38 , each will see one-half of the bias voltage, thus reducing the rate of drop in MR % as the bias voltage increases. During operation, any topological positive coupling from bottom and top are canceled. This type of structure is designed for MRAM applications. During operation of magnetic element 30 , magnetic layers 32 and 40 will point and lock into an anti-parallel orientation due to magnetic flux closure and reduced magnetic energy for smaller dimension devices. Magnetic layers 46 and 48 will remain free to rotate so that to stay in one of the two co-linear states to magnetic layers 32 and 40 , thus making this structure suitable for use in memory devices, such as MRAM applications. Alternatively, in a larger dimension MRAM cell, pinning from an antiferromagnetic layer can be used to pin the bottom 12 ′ and top 20 ′ magnetic layers.
It should be understood that it is anticipated by this disclosure to include SAF structure 36 that is formed between two tunnel barrier layers 34 and 38 as previously disclosed, or alternatively below bottom tunnel barrier layer 34 , or on a surface 39 of top tunnel barrier layer 38 . The inclusion of SAF structure 36 between bottom tunnel barrier layer 34 and top tunnel barrier layer 38 is described with respect to FIG. 3, for ease of disclosure.
Referring now to FIG. 4, illustrated in simplified sectional view is a fourth embodiment of a magnetic element, according to the present invention. It should be noted that all components of the third embodiment as illustrated in FIG. 3, that are similar to components of the fourth embodiment, are designated with similar numbers, having a prime added to indicate the different embodiment. Similar to the structure described with regard to FIG. 3, this structure includes a magnetic element 30 ′ including as a part thereof a synthetic antiferromagnetic (SAF) structure. Magnetic element 30 ′ includes a bottom pinned magnetic layer 32 ′, a bottom tunnel barrier layer 34 ′, a SAF structure 36 ′, a top tunnel barrier layer 38 ′, and a top pinned magnetic layer 40 ′. Bottom pinned magnetic layer 32 ′, SAF structure 36 ′ and top pinned magnetic layer 40 ′ include ferromagnetic layers. Bottom magnetic layer 32 ′ is formed on a diffusion barrier layer 42 ′ which is formed on a metal lead 44 ′. Diffusion barrier layer 42 ′ is typically formed of tantalum nitride (TaN), and aids in the thermal stability of magnetic element 30 . Metal lead 44 ′ is typically formed on some type of dielectric material (not shown).
Bottom and top pinned ferromagnetic layers 32 ′ and 40 ′ are described as pinned, or fixed, in that their magnetic moment is prevented from rotation in the presence of an applied magnetic field. Ferromagnetic layers 32 ′ and 40 ′ are typically formed of alloys of one or more of the following: nickel (Ni), iron (Fe), and cobalt (Co) and each include a top surface 33 ′ and 41 ′, respectively, and a bottom surface 31 ′ and 39 ′, respectively.
SAF structure 36 ′ includes a bottom free magnetic layer 46 ′, and a top free magnetic layer 48 ′ formed antiparallel to each other and perpendicularly aligned relative to bottom pinned ferromagnetic layer 32 ′ and top pinned ferromagnetic layer 40 ′. Bottom free magnetic layer 46 ′ and top free magnetic layer 48 ′ are separated by an exchange spacer layer 50 ′, typically formed of a layer of ruthenium (Ru) or the like. Antiparallel alignment between free magnetic layers 46 ′ and 48 ′ is achieved through an exchange spacer layer 50 ′ which induces antiferromagnetic coupling between bottom free magnetic layer 46 ′ and top free magnetic layer 48 ′, or through end magnetostatic coupling, or other means.
Free ferromagnetic layers 46 ′ and 48 ′ and pinned ferromagnetic layer 32 ′ and 40 ′ are typically formed of alloys of one or more of the following: nickel (Ni), iron (Fe), and cobalt (Co). Pinned ferromagnetic layers 32 ′ and 40 ′ are described as having a thickness within a range of 5-5000 Å. Free ferromagnetic layers 46 ′ and 48 ′ are described as each having a thickness generally less than 500 Å. A second diffusion barrier layer 52 ′ is formed on an uppermost surface 41 ′ of top pinned magnetic layer 40 ′. A metal lead 54 ′ is formed on a surface of second diffusion barrier layer 52 ′.
In this particular embodiment, bottom tunnel barrier layer 34 ′ and top tunnel barrier layer 38 ′ are formed of an oxidized aluminum, generally having the formula AlO x , where x≦1.5. It is disclosed that in this embodiment, which includes SAF structure 36 ′, bottom tunnel barrier layer 34 ′ and top tunnel barrier layer 38 ′ are of the same type. More particularly, bottom tunnel barrier layer 34 ′ and top tunnel barrier layer 38 ′ are described as being normal tunnel barrier layers, such that the magnetic tunnel junction has a maximum resistance (R) for anti-parallel aligned magnetic electrodes, and a minimum resistance (R) for parallel aligned magnetic electrodes. More specifically, with free ferromagnetic layers 46 ′ and 48 ′ oppositely opposed, when bottom free magnetic layer 46 ′ is rotated to be anti-parallel to pinned magnetic layer 32 ′ and top free magnetic layer 48 ′ is rotated to be anti-parallel to pinned magnetic layer 40 ′, maximum resistance is achieved. When bottom free magnetic layer 46 ′ is rotated to be parallel to pinned magnetic layer 32 ′ and top free magnetic layer 48 ′ is rotated to be parallel to pinned magnetic layer 40 ′, minimum resistance is achieved. This type of structure provides the inclusion of the same type of material for the formation of tunnel barrier layers 34 ′ and 38 ′, and for a higher magnetoresistance ratio (MR %) or stronger signal, and less voltage dependence. Typically the MR % decreases as the bias voltage increases. Accordingly, by including dual tunnel barrier layers, 34 ′ and 38 ′, each will see one-half of the bias voltage, thus reducing the rate of drop in MR % as the bias voltage increases. During operation, any topological positive coupling from bottom and top are canceled. This type of structure is designed for read head and magnetic sensor applications. During operation of magnetic element 30 ′, magnetic layers 32 ′ and 40 ′ will point and lock into an anti-parallel orientation due to magnetic flux closure and reduced magnetic energy. Magnetic layers 46 ′ and 48 ′ will remain free to rotate around the perpendicular direction to magnetic layers 32 ′ and 40 ′ when they detect a magnetic field, thus producing linear voltage change in proportion to the magnetic field it detects, and making this structure suitable for use in magnetic read head devices and magnetic sensors.
It should be understood that it is anticipated by this disclosure to include SAF structure 36 ′ that is formed between two tunnel barrier layers 34 ′ and 38 ′ as previously disclosed, or alternatively below bottom tunnel barrier layer 34 ′, or on a surface 39 ′ of top tunnel barrier layer 38 ′. The inclusion of SAF structure 36 ′ between bottom tunnel barrier layer 34 ′ and top tunnel barrier layer 38 ′ is described with respect to FIG. 4, for ease of disclosure.
Thus, a magnetic element with an improved magnetoresistance ratio and fabricating method thereof is disclosed in which the magnetoresistance ratio is improved based on the inclusion of dual tunnel barrier layers. As disclosed, this technique can be applied to devices using patterned magnetic elements, such as magnetic sensors, magnetic recording heads, magnetic recording media, or the like. Accordingly, such instances are intended to be covered by this disclosure
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An improved and novel magnetic element and fabrication method. The magnetic element ( 10;30 ) including a bottom pinned ferromagnetic layer ( 12;32 ) and a top pinned ferromagnetic layer ( 20;40 ) fabricated antiparallel to one another. The magnetic element ( 10;30 ) further including a bottom tunnel barrier layer ( 14;34 ), a free ferromagnetic layer ( 16;46 and 48 ) and a top tunnel barrier layer ( 18;38 ) formed between the bottom pinned ferromagnetic layer ( 12;32 ) and the top pinned ferromagnetic layer ( 20;40 ). The structure is defined as including two (2) tunnel barrier layers in which one tunnel barrier layer is normal ( 18 ) and one is reversed ( 14 ), or a structure in which the two tunnel barrier layers are of the same type ( 34; 38 ) with the structure further includes a SAF structure ( 36 ) to allow for consistently changing magnetoresistance ratios across both tunnel barriers. The magnetic element ( 10;30 ) having an improved magnetoresistance ratio and a decrease in voltage dependence.
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FIELD OF THE INVENTION
[0001] The invention relates to normalizing data and more particularly to normalizing broadband network performance metrics produced by disparate network elements.
BACKGROUND OF THE INVENTION
[0002] Communications networks are expanding and becoming faster in response to demand for access by an ever-increasing amount of people and for demand for quicker response times and more data-intensive applications. Examples of such communications networks are for providing computer communications. There are an estimated 53 million dial-up subscribers currently using telephone lines to transmit and receive computer communications. Presently, a multitude of computer users are turning to cable communications. It is estimated that there are 5.5 million users of cable for telecommunications at present, with that number expected to increase rapidly in the next several years.
[0003] In addition to cable, there are other currently-used or anticipated broadband communications network technologies, with others as yet to be created sure to follow. Examples of other presently-used or presently-known broadband technologies are: digital subscriber line (DSL) with approximately 3 million subscribers, satellite, fixed wireless, free-space optical, datacasting, and High-Altitude Long Operation (HALO).
[0004] Broadband networks currently serve millions of subscribers, with millions more to come. These networks use large numbers of network elements, such as Cable Modem Termination Systems (CMTSs) physically distributed over wide areas, and other network elements, such as Cable Modems (CMs) located, e.g., in subscribers' homes. With so many network elements needed present and future due to so many subscribers present and future, and changing demands on network performance, there is a large market for network elements and thus there are numerous makers of network elements. Different makers often process similar data differently, and even the same maker may process the same data differently with network elements of different configurations, e.g., different models, hardware versions, software versions, and/or element settings.
SUMMARY OF THE INVENTION
[0005] In general, in an aspect, the invention provides a system, for use with a broadband network, that includes a data collector configured to be coupled to at least a portion of the network and configured to obtain network performance metrics from network elements in the at least a portion of the network, and a data processor configured to process the obtained metrics to yield normalized metrics by adjusting the obtained metrics, as appropriate, such that similar metric types with different values obtained from disparate network elements based upon similar network performance associated with the disparate elements will be normalized to have normalized values that are similar.
[0006] Implementations of the invention may include one or more of the following features. The processor is configured to adjust each the obtained metrics depending upon device-specific information of each network element. The device-specific information includes at least one of make, model, hardware version, software version, and element settings associated with each of the network elements. The data collector is further configured to obtain at least one of MIB objects and command line interface information from the network elements and the data processor is further configured to determine the device-specific information from the at least one of MIB objects and command line interface information.
[0007] Further implementations of the invention may include one or more of the following features. The network performance metrics are remotely-accessible standard management instrumentation. The network is a DOCSIS network and the network performance metrics include at least one of signal-to-noise ratio, power level, equalizer coefficients, settings information, error information, counter information, bandwidth, quality of service, latency, and jitter. At least one of the data collector and the data processor comprise software instructions and a computer processor configured to read and execute the software instructions.
[0008] In general, in another aspect, the invention provides a computer program product residing on a computer-readable medium and including computer-executable instructions for causing a computer to obtain network performance metrics from broadband network elements, use network management instrumentation associated with the broadband network elements to determine which of multiple calibration algorithms to apply to the obtained metrics, and normalize the obtained metrics using the determined calibration algorithm to yield normalized metrics by adjusting the obtained metrics, as appropriate, such that a first metric from a first network element and having a first value and a second metric, from a second network element and of a similar type as the first metric, and having a second value, different from the first value, yield first and second normalized metrics having similar values if the first and second metric values are associated with similar network performance at the first and second network elements.
[0009] Implementations of the invention may include one or more of the following features. The network management instrumentation includes MIB objects and the instructions for causing the computer to use the network management instrumentation are for causing the computer to identify the first and second network elements using the MIB objects. The instructions for causing the computer to identify the first and second network elements cause the computer to determine at least one of make, model, hardware version, software version, and settings of each of the first and second network elements.
[0010] In general, in another aspect, the invention provides a method of calibrating a broadband network performance metric from a first broadband network element configured to determine the performance metric in a way that yields a different value of the metric than another way implemented by a different broadband network element. The method includes obtaining network performance data, determining first values of the network performance metric from the obtained network performance data, obtaining second values of the network performance metric provided by the first broadband network element, the second values being correlated to the first values, and deriving a relationship between the first values and the second values of the network performance metric to convert the first values to the second values.
[0011] Implementations of the invention may include one or more of the following features. Obtaining the first values comprises measuring characteristics of the network associated with the first network element, the network is a DOCSIS network, and wherein obtaining the second values comprises polling MIB objects of the first network element. Deriving the relationship comprises curve fitting the first and second values. Deriving the relationship further comprises determining coefficients of a polynomial describing the second values as a function of the first values. The network performance data are obtained corresponding to a range of first values and second values. The method further includes injecting test data into at least a portion of the network associated with the network element to affect the network performance data.
[0012] Various aspects of the invention may provide one or more of the following advantages. Performance metrics can be made to be standardized across disparate network elements. Substantially uniform reporting of historical data is possible when comparing network quality based on data from different network elements. Substantially consistent reporting of network exceptions (asynchronous notification of user-specified network state) across network elements of different vendors, hardware, software, and/or settings is possible. It is possible to report network metrics that correlate better to measurements obtained through more accurate physical measurement of the network such as using a spectrum analyzer to measure power or signal-to-noise ratio, or by reading network element documentation regarding make, model, hardware, and software. Vendor-proprietary and/or vendor-specific management features (network information, e.g., that are outside the DOCSIS™ (Data Over Cable Service Interface Specification) standard) may be used in a generic management system, e.g., by processing information from different network element arrangements differently.
[0013] These and other advantages of the invention, along with the invention itself, will be more fully understood after a review of the following figures, detailed description, and claims.
BRIEF DESCRIPTION OF THE FIGURES
[0014] [0014]FIG. 1 is a simplified diagram of a telecommunications network including a network monitoring system.
[0015] [0015]FIG. 2 is a block diagram of a software architecture of a portion of the network monitoring system shown in FIG. 1.
[0016] [0016]FIG. 3 is a simplified block diagram of a calibration arrangement including calibration equipment connected to a portion of the network shown in FIG. 1.
[0017] [0017]FIG. 4 is a block flow diagram of a process of calibrating network elements.
[0018] [0018]FIG. 5 is a block flow diagram of a process of normalizing network performance metrics.
[0019] [0019]FIG. 6 is a block flow diagram of another process of calibrating network elements.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] The invention provides techniques for calibrating and normalizing monitoring data in networks, especially DOCSIS networks. For DOCSIS networks, Management Information Base (MIB) objects (management instrumentation) are analyzed to determine relevant attributes (e.g., make, model, hardware version, software version, network element settings (e.g., amount of error correction) of a network element such as a CMTS or CM. Knowing the relevant attributes for the network element, a corresponding predetermined normalization algorithm is applied to convert a performance metric (i.e., measurements of network performance based on raw data), determined by the element from monitored data, into a normalized metric. The normalization compensates for different techniques used by different element configurations to determine the same metric. The normalization uses calibration information that may be obtained by testing elements of various makes, models, hardware versions, software versions, and settings. Test results are analyzed to determine how similar metrics determined by the tested elements from similar monitored data should be converted to yield similar normalized metric values. Value in this context can be quantity information (e.g., numeric, magnitude value), and/or format information (e.g., how the information is arranged). Determining how the data should be converted yields the calibration information. Calibration information may also be obtained using knowledge of calibration information from one or more network elements and one or more relationships between how metrics are calculated by the network elements for which calibration information is known and by the element for which calibration information is to be obtained.
[0021] Referring to FIG. 1, telecommunication system 10 includes DOCSIS (data over cable service interface specification) networks 12 , 14 , 16 , a network monitoring system 18 that includes a platform 20 and an applications suite 22 , a packetized data communication network 24 such as an intranet or the global packet-switched network known as the Internet, and network monitors/users 26 . The networks 12 , 14 , 16 are configured similarly, with the network 12 including CMTSs 32 and consumer premise equipment (CPE) 29 including inter alia a cable modem (CM) 30 , an advanced set-top box (ASTB) 31 , and a multi-media terminal adaptor (MTA) 33 . The CPE 29 could include other devices such as home gateways, with the devices shown being exemplary only, and not limiting Users of the DOCSIS networks 12 , 14 , 16 , communicate, e.g., through the computer 28 and the cable modem (CM) 30 (or through a monitor 35 and the ASTB 31 , or through a multi-media terminal 37 and the MTA 33 ) to one of the multiple CMTSs 32 .
[0022] Data relating to operation of the network 12 are collected by nodes 34 , 36 , 38 . The data include data regarding operation of the CMTSs 32 , the CM 30 , the ASTB 31 , the MTA 33 , and the CPE 29 (here the computer 28 , the monitor 35 , and the terminal 37 ). The nodes 34 , 36 , 38 can communicate bi-directionally with the networks 12 , 14 , 16 and that manipulate the collected data to determine metrics of network performance (including network element state). These metrics can be forwarded, with or without being combined in various ways, to a controller 40 within the platform 20 .
[0023] The controller 40 provides a centralized access/interface to network elements and data, applications, and system administration tasks such as network configuration, user access, and software upgrades. The controller can communicate bi-directionally with the nodes 34 , 36 , 38 , and with the applications suite 22 . The controller 40 can provide information relating to performance of the networks 12 , 14 , 16 to the application suite 22 .
[0024] The application suite 22 is configured to manipulate data relating to network performance and provide data regarding the network performance in a user-friendly format through the network 24 to the network monitors 26 . The monitors 26 can be, e.g., executives, product managers, network engineers, plant operations personnel, billing personnel, call center personnel, or Network Operations Center (NOC) personnel.
[0025] The system 18 , including the platform 20 and the application suite 22 , is preferably comprised of software instructions in a computer-readable and computer-executable format that are designed to control a computer. The software can be written in any of a variety of programming languages such as C++. Due to the nature of software, however, the system 18 may comprise software (in one or more software languages), hardware, firmware, hard wiring or combinations of any of these to provide functionality as described above and below. Software instructions comprising the system 18 may be provided on a variety of storage media including, but not limited to, compact discs, floppy discs, read-only memory, random-access memory, zip drives, hard drives, and any other storage media for storing computer software instructions.
[0026] Referring also to FIG. 2, the node 34 (with other nodes 36 , 38 configured similarly) includes a data distributor 42 , a data analyzer 44 , a data collector controller 46 , a node administrator 48 , an encryption module 50 , a reporting module 52 , a topology module 54 , an authorization and authentication module 56 , and a database 58 . The elements 44 , 46 , 48 , 50 , 52 , 54 , and 56 are software modules designed to be used in conjunction with the database 58 to process information through the node 34 . The node administration module 48 provides for remote administration of node component services such as starting, stopping, configuring, status monitoring, and upgrading node component services. The encryption module 50 provides encrypting and decrypting services for data passing through the node 34 . The reporting module 52 is configured to provide answers to data queries regarding data stored in the database 58 , or other storage areas such as databases located throughout the system 18 . The topology module 54 provides for management of network topology including location of nodes, network elements, and high-frequency coax (HFC) node combining plans. Management includes tracking topology to provide data regarding the network 12 for use in operating the network 12 (e.g., how many of what type of network elements exist and their relationships to each other). The authorization and authentication module 56 enforces access control lists regarding who has access to a network, and confirms that persons attempting to access the system 18 are who they claim to be. The data distributor 42 , e.g., a publish-subscribe bus implemented in JMS, propagates information from the data analyzer 44 and data collector controller 46 , that collect and analyze data regarding network performance from the CMTSs 32 and CPE 30 , 31 , 33 .
[0027] The data collector controller 46 is configured to collect network data from, preferably all elements of, the network 12 , and in particular the network elements such as the CMTSs 32 and any cable modems such as the cable modem 30 . The controller 46 is configured to connect to network elements in the network 12 and to control the configuration to help optimize the network 12 . Thus, the system 18 can automatically adjust error correction and other parameters that affect performance to improve performance based on network conditions. The data collector controller 46 can obtain data from the network 12 synchronously, by polling devices on the network 12 , or asynchronously. The configuration of the controller 46 defines which devices in the network 12 are polled, what data are collected, and what mechanisms of data collection are used. The controller 46 is configured to use SNMP MIB (Simple Network Management Protocol Management Information Base) objects for both cable modems and CMTSs, CM traps and CMTS traps (that provide asynchronous information) and syslog files. The collector 46 synchronously obtains data periodically according to predetermined desired time intervals in accordance with what features of the network activity are reflected by the corresponding data. Whether asynchronous or synchronous, the data obtained by the controller 46 is real-time or near real-time raw data concerning various network performance characteristics of the network 12 . For example, the raw data may be indicative of signal to noise ratio (SNR), power, CMTS resets, equalizer coefficients, settings information, error information, counter information, bandwidth, quality of service, latency, and/or jitter, etc. The controller 46 is configured to pass the collected raw data to the data analyzer 44 for further processing.
[0028] The data analyzer 44 is configured to accept raw data collected by the controller 46 and to manipulate the raw data into metrics indicative of network performance. Raw data from which values of the network performance metrics are determined may be discarded.
[0029] The metrics are standardized/normalized to compensate for different techniques for determining/providing raw network data from various network element configurations, e.g., from different network element manufacturers. For example, two network elements made by different manufacturers, or two network elements made by the same manufacturer but having different hardware, software, and/or element settings may determine raw data, e.g., SNR, differently. The different devices may therefore report different raw data values for the same characteristic in response to the same input data. To help provide meaningful data for large networks that include different element attributes, the data analyzer 44 can normalize raw data values from various elements so that for the same reported characteristic from two network elements, the normalized values will be approximately, if not exactly, the same for the same input data applied to the two network elements.
[0030] The node 34 is further configured to use MIB objects to identify the attributes of network elements to determine how to normalize data from the elements. The node 34 can analyze MIB objects to determine a network device's make, model, software version, hardware version, and settings (and any other trait to be used to determine which normalization algorithm to use). Based on the identity of the network element, the node 34 selects a predetermined normalizing algorithm to be applied to the particular data, with algorithms being tailored to the device attributes and to the particular data, e.g., SNR versus power. The algorithms are stored in, or associated with, the node 34 and are determined by calibration equipment.
[0031] Referring to FIGS. 1 and 3, calibration equipment 60 includes a test data injector 62 , a data detector 64 , an algorithm generator 66 , a channel detector 68 , and a channel emulator 70 . Although the devices 62 , 64 , 66 , 68 , 70 are shown separate, these devices may be incorporated into fewer devices, e.g., a single device, or more devices. The channel emulator 70 is configured to emulate channel conditions (e.g., signal quality) of a network distribution for a CMTS 39 from the set 32 of CMTSs and the CM 30 . The emulator 70 can be, e.g., a TAS 8250 made by Spirent plc of West Sussex, United Kingdom. The channel detector 68 is configured to read signal quality on the channels 72 , 74 and report this information, e.g., to a user (not shown). The channel detector 68 can be, e.g., a Vector Signal Analyzer made by Agilent Technologies of Palo Alto, Calif. The injector 62 is configured to inject test data, e.g., impairments such as noise, into a downstream channel 72 and/or an upstream channel 74 between the CM 30 and a CMTS 39 from the set 32 of CMTSs. The data detector 64 is configured to detect packetized data on the channels 72 , 74 and provide these data to the algorithm generator 66 .
[0032] The algorithm generator 66 is configured to receive the detected data from the detector 64 and MIB-reported data from the CMTS 39 , and to analyze these data to determine algorithms relating actual channel characteristics to MIB-reported characteristics. The analysis may be, e.g., curve fitting data points of measured data and output MIB-reported data to derive functions describing the actual to MIB-reported data relationship. For example, second order, third degree, polynomials may be derived to express channel noise ratio (CNR) as a function of SNR, where SNR is an unmodulated signal inside a network element and CNR is a modulated signal outside a network element. These polynomials provide conversion algorithms and can be stored by the generator 66 in a storage area accessible by the node 34 (e.g., in the node 34 ). The stored algorithms are stored in association with the network element attributes, such that they are accessible by the node 34 using the network element attributes. Other techniques for normalization include a combination of curve fitting and using other MIB objects that can be used to derive the status of the normalized MIB objects. For example, SNR can be inferred by curve fitting and using known influences a variety of other MIB objects including codeword errors, power levels, equalizer settings, and packet size distributions. For example, the results from curve fitting may be modified given knowledge of effects of other MIB objects on, e.g, SNR. Additionally, mathematical techniques that are more complex than curve fitting could be used.
[0033] In operation, referring to FIG. 4, with further reference to FIGS. 1 - 3 , a process 100 for calibrating network elements to determine calibration information using the node 34 includes the stages shown. The process 100 , however, is exemplary only and not limiting. The process 100 can be altered, e.g., by having stages added, removed, or rearranged. The calibrating process 100 standardizes network elements by determining deviations from a standard to ascertain correction factors.
[0034] At stage 102 , the node 34 determines network element attributes. The network elements, e.g., the attributes of the CMTSs 32 and/or the CM 30 are determined by analyzing appropriate MIB objects. For example, for a DOCSIS network, the enterprise-specific System Object Idententifier from the system group of IETF MIB-II (RFC-1213):
[0035] sysObjectID OBJECT-TYPE
[0036] SYNTAX OBJECT IDENTIFIER
[0037] ACCESS read-only
[0038] STATUS mandatory
[0039] DESCRIPTION
[0040] “The vendor's authoritative identification of the network management subsystem contained in the entity. This value is allocated within the SMI enterprises subtree (1.3.6.1.4.1) and provides an easy and unambiguous means for determining ‘what kind of box’ is being managed. For example, if vendor ‘Flintstones, Inc.’ was assigned the subtree 1.3.6.1.4.1.4242, it could assign the identifier 1.3.6.1.4.1.4242.1.1 to its ‘Fred Router’.”
[0041] {system 2 }
[0042] All DOCSIS devices implement the sysObjectID MIB object. Examples of how to describe each device in terms of its sysObjectID and how to map the device to a normalization function are included in Appendix A. Each of these examples provide what is referred to as a Normalization File. Other ways to identify element information are acceptable, such as using sysdescription MIBs, that report software version.
[0043] At stage 103 , network attributes are set. The test data injector 62 is set to inject desired data and the channel emulator 70 is set to provide desired network-emulating data (e.g., noise, RF parameters such as delay and microreflections).
[0044] At stage 104 , the test data injector 62 injects appropriate test data into the upstream line 70 and/or the downstream line 68 . The injector 62 introduces impairments (noise) in the appropriate channel(s) 68 , 70 for processing and reporting by the network elements 30 , 39 . The injector 62 may not inject test data if non-performance data are to be determined and normalized.
[0045] At stage 106 , the network performance in response to the introduced noise is measured. The data detector 64 determines actual network performance, e.g. CNR, on the channel(s) 68 , 70 . If no test data are injected by the test data injector 62 , the detector 64 detects non-performance information, such as format information (that is often vendor-specific), for metrics. For example, system description (e.g., indicating hardware and software versions) often varies in format between network element vendors. The detector 64 provides the detected data to the algorithm generator 66 .
[0046] At stage 108 , the algorithm generator 66 obtains MIB-reported performance. The network elements 30 , 39 provide MIB objects indicative of network performance, with these objects typically indicating different values than those detected by the detector 64 . Examples of MIB objects for various performance metrics are provided below. These examples are for MIB-based SNR readings in a DOCSIS network, and are exemplary only and not limiting of the invention.
[0047] CM Downstream SNR
[0048] CM downstream SNR is available for the CM's downstream interface in the CM docsIfSignalQualityTable via object docsIfSigQSignalNoise. The following MIB object is used from IETF RFC-2670 to report downstream channel SNR for the downstream interface on a CM.
docsIfSigQSignalNoise OBJECT-TYPE SYNTAX TenthdB UNITS “dB” MAX-ACCESS read-only STATUS current DESCRIPTION “Signal/Noise ratio as perceived for this channel. At the CM, describes the Signal/Noise of the downstream channel. At the CMTS, describes the average Signal/Noise of the upstream channel.” REFERENCE “DOCSIS Radio Frequency Interface specification, Table 2-1 and 2-2” ::= { docsIfSignalQualityEntry 5 }
[0049] CMTS per Upstream Channel SNR
[0050] CMTS per upstream channel SNR is found in the docsIfSignalQualityTable for each upstream interface instance attached to the CMTS reported via object docsIfSigQSignalNoise. The following MIB object is used from IETF RFC-2670 to report upstream channel SNR for each upstream interface on a CMTS:
docsIfSigQSignalNoise OBJECT-TYPE SYNTAX TenthdB UNITS “dB” MAX-ACCESS read-only STATUS current DESCRIPTION “Signal/Noise ratio as perceived for this channel. At the CM, describes the Signal/Noise of the downstream channel. At the CMTS, describes the average Signal/Noise of the upstream channel.” REFERENCE “DOCSIS Radio Frequency Interface specification, Table 2-1 and 2-2” ::= { docsIfSignalQualityEntry 5 }
[0051] CMTS per CM Upstream SNR
[0052] CMTS per CM upstream SNR differs from the channel SNR measurement described above. CMTS per CM upstream SNR is a measurement made and reported for each CM attached to the CMTS in the docslfCmtsCmStatusTable using the object docslfCmtsCmStatusSignalNoise. The following MIB object is used from IETF RFC-2670 to report upstream channel SNR per CM for each CM on a CMTS:
docsIfCmtsCmStatusSignalNoise OBJECT-TYPE SYNTAX TenthdB UNITS “dB” MAX-ACCESS read-only STATUS current DESCRIPTION “Signal/Noise ratio as perceived for upstream data from this Cable Modem. If the Signal/Noise is unknown, this object returns a value of zero.” ::= { docsIfCmtsCmStatusEntry 13 }
[0053] At stage 110 , the algorithm generator 66 analyzes the measured actual performance data detected by the detector 64 and the MIB-reported data from the CMTS 39 , and determines a normalizing algorithm. The generator 66 analyzes associated data 10 (associated in time of measurement and MIB-reporting) by curve fitting the data, that may be arranged in a table such as Table 1 provided below for CM Downstream SNR vs. CNR. Examples of algorithm determinations are provided below.
[0054] CM Downstream SNR
TABLE 1 Hypothetical Measured Downstream Channel CNR vs. SNR (docsIfSigQSignalNoise) SNR CNR (MIB) (Actual) 35.2 35 35.1 34 35.1 33 34.9 32 33 31 33 30 33 29 32.8 28 31.3 27 31.3 26 29.8 25 29.5 24 28.6 23 28.3 22 27.6 21 26.4 20 25.5 19 24.6 18 24 17.5 23.5 17 22.9 16.5 22.2 16 21.8 15.5 21.5 15 20.8 14.5 20 14 19 13.5 19 13 19 12.5 18 12 17 11.5 16.9 11 15.5 10.5 15.5 10 13.9 9.5
[0055] A second order polynomial (3 rd degree) can be used to fit this curve. In general form, the polynomial is:
CNR=a 3* SNR 3 +a 2* SNR 2 +a 1 * SNR+a 0
[0056] In the case of the example calibration data provided in Table 1, the normalization polynomial coefficients for Vendor X, and attributes i (with vendor being an attribute), would be:
a 3=0.0011, a 2=−0.0499 , a 1=1.5047 , a 0=−5.0566
[0057] With the results of this calibration available a normalization function can be defined for vendor X, and attributes i:
CNR=f vendorX−i ( SNR )
[0058] In this way, a normalization function can be defined for all CM vendors. An algorithm could be applied to each CM that returns a poll.
For each CM { Identify CM attributes (vendorx 1 ) cnr = snrtocnr(vendorx i , docsIfSigQSignalNoise) }
[0059] CMTS per Upstream Channel SNR
[0060] A table similar to Table 1 would result. With the results of this calibration available a normalization function can be defined for CMTS vendor X, and attributes i:
CNR=f vendorX−i ( SNR )
[0061] In this way, a normalization function can be defined for all CMTS vendors. An algorithm could be applied to each CMTS that returns a poll.
Identify CMTS attributes (vendorx i ) For each CMTS upstream interface { cnr = snrtocnr(vendorx i , docsIfSigQSignalNoise) }
[0062] CMTS per CM Upstream SNR
[0063] A table similar to the one described in FIG. 2 would result. With the results of this calibration available a normalization function can be defined for CMTS vendor X, and attributes i:
CNR=f vendorX−i ( SNR )
[0064] In this way, a normalization function can be defined for all CMTS vendors. An algorithm could be applied to each CMTS that returns a poll.
Identify CMTS attributes (vendorx 1 ) For each CM in the CmtsCmStatusTable { cnr = snrtocnr(vendorx 1 , docsIfCmtsCmStatusSignalNoise) }
[0065] At stage 112 , the determined algorithms are stored by the algorithm generator 66 . The generator 66 stores the algorithm(s) in association with the attributes of the network element associated with the algorithm such that the node 34 can retrieve the appropriate algorithm using attribute information. The algorithm can be stored in the node 34 , or elsewhere, such as a database, that is accessible by the node 34 .
[0066] Referring to FIG. 5, with further reference to FIGS. 1 - 3 , a process 120 for normalizing network performance metrics using the node 34 includes the stages shown. The process 120 , however, is exemplary only and not limiting. The process 120 can be altered, e.g., by having stages added, removed, or rearranged.
[0067] At stage 122 , the node 34 determines network element attributes. The network elements, e.g., the attributes of the CMTSs 32 and/or the CM 30 are determined by analyzing appropriate MIB objects.
[0068] At stage 124 , the node 34 uses the determined network attributes to access an appropriate normalizing algorithm. The node 34 searches the appropriate storage area where algorithms are stored, and retrieves the algorithm associated with the determined attributes. If no stored algorithm is associated with the determined attributes, then the raw MIB-reported data from the network element are returned untreated and included with the corrected data in any subsequent calculations. More than one set of attributes may be associated with a single algorithm, e.g., if a metric of interest is calculated the same by elements having different attribute sets.
[0069] At stage 126 , the node 34 applies the normalizing algorithm to normalize the MIB-reported data from the network element (e.g., CMTS 39 , CM 30 ). The resulting normalized metric(s) may be passed by the node 34 to other portions of the system 10 for further processing, e.g., to reflect network performance for the users 26 as described in co-filed applications entitled “NETWORK PERFORMANCE MONITORING,” U.S. Ser. No. (to be determined), “NETWORK PERFORMANCE DETERMINING,” U.S. Ser. No. (to be determined), and “NETWORK PERFORMANCE PARAMETERIZING,” U.S. Ser. No. (to be determined), each of which is incorporated here by reference.
[0070] Other embodiments are within the scope and spirit of the appended claims. For example, due to the nature of software, functions described above can be implemented using software, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Other MIB objects and network performance metrics than those listed may be used. Further, network element configuration may be obtained using techniques other than obtaining MIB objects. For example, a command line interface (cli) may be used to determine element configuration. The standard to which metrics are normalized may be different than a measured-data standard. Also, a normalized metric may be the same as an un-normalized metric if the un-normalized metric is the standard.
[0071] The invention is particularly useful with DOCSIS networks. The DOCSIS 1.1 specifications SP-BPI+, SP-CMCI, SP-OSSIv1.1, SP-RFIv1.1, BPI ATP, CMCI ATP, OSS ATP, RFI ATP, and SP-PICS, and DOCSIS 1.0 specifications SP-BPI, SP-CMTRI, SP-CMCI, SP-CMTS-NSI, SP-OSSI, SP-OSSI-RF, SP-OSSI-TR, SP-OSSI-BPI, SP-RFI, TP-ATP, and SP-PICS are incorporated here by reference. The invention, as embodied in the claims, however, is not limited to these specifications, it being contemplated that the invention embodied in the claims is useful for/with, and the claims cover, other networks/standards such as DOCSIS 2.0, due to be released in December, 2001.
[0072] Also, referring to FIG. 6, process 130 for calibrating network elements may be used. The process 130 uses the node 34 and includes the stages shown. The process 130 , however, is exemplary only and not limiting. The process 130 can be altered, e.g., by having stages added, removed, or rearranged. At stage 132 , the node determines the network element attributes as described above (see stage 102 of process 100 ). At stage 134 , the node, e.g., using MIB objects and knowledge of attributes and associated conversion techniques, determines a conversion technique for converting raw data to MIB-reported data for a metric of interest by the network element of interest. At stage 136 , the node 34 derives a normalizing algorithm for the element of interest. The derivation is based on knowledge of the conversion technique used by the element of interest, based on knowledge of one or more normalizing algorithms associated with one or more other conversion techniques. The derivation is also based on knowledge of those one or more other conversion techniques and/or their relationships to the conversion technique used by the element of interest. At stage 128 , the derived algorithm is stored in association with the element's attributes.
[0073] Also, while the description above focused on normalizing network performance metrics (e.g., FIG. 5 and related discussion), normalization may be applied to numerous types of network-element information including, but not limited to, performance metrics, other metrics, and format of network-element-reported data (e.g., hardware and software version).
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A system, for use with a broadband network, includes a data collector configured to be coupled to at least a portion of the network and configured to obtain network performance metrics from network elements in the at least a portion of the network, and a data processor configured to process the obtained metrics to yield normalized metrics by adjusting the obtained metrics, as appropriate, such that similar metric types with different values obtained from disparate network elements based upon similar network performance associated with the disparate elements will be normalized to have normalized values that are similar.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 USC 119(e) from U.S. provisional application 60/781,652 filed Mar. 14, 2006, the disclosure of which is included herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the detecting and identifying pedestrians around a powered industrial vehicle and more particularly the present invention detects and identifies pedestrians around a powered industrial vehicle using multiple cameras that provide images of the scene, preferably in an angle 360° (angular) around the powered industrial vehicle.
BACKGROUND OF THE INVENTION AND PRIOR ART
[0003] An operator of a powered industrial vehicle is required to notice pedestrians in the area around which the vehicle is operating. Prior art solutions for detecting pedestrians include the use of electromagnetic radiation emitters coupled with RADAR sensors, laser sensors, and/or SONAR (ultrasonic) sensors to provide the operator with some indication that a pedestrian may be present in the area around the vehicle.
[0004] A significant limitation of prior art systems is in the inability to discern whether the object being detected is an insignificant inanimate object (e.g. trash, boxes, poles, etc.) or a pedestrian. As a result, prior art systems alert the industrial truck operator of the presence of every object thereby creating multiple false alarms. These false alarms annoy the operator with unnecessary warnings, and cause the operator to be less sensitive to the warnings.
[0005] Furthermore, radar and laser sensors as well as ultrasound sensors have the disadvantage that in the immediate vehicle surroundings they are able to detect only a small region of the surroundings because of their small aperture angle, which typically provides a narrow FOV. Thus, a large number of sensors is required if the entire vehicle surroundings are to be detected using such sensors.
[0006] An example of a laser based system, is disclosed in U.S. Pat. No. 7,164,118 (hereinafter U.S. Pat. No. '118), by Anderson et al U.S. Pat. No. '118 discloses a method of detecting presence of an object and the distance between the system and an object using a laser mounted on an industrial vehicle. The transmitter emits linear beams of electromagnetic radiation with a transmitted radiation pattern within a defined spatial zone. A camera collects an image of the defined spatial zone. A data processor detects a presence of an object in the collected image based on an observed illumination radiation pattern on an object formed by at least one of the linear beams. A distance estimator estimates a distance between the object and the optical device.
[0007] There are also prior art systems using imaging devices to image the scene in an angle 360° horizontally around a vehicle. Such a system is disclosed in US patent application 2004/0075544 (hereinafter US '544), by Janssen Holger. US '544 uses two optical sensors that act as a pair of stereo cameras. The sensors are coupled with fisheye lenses, which have a very wide-angle of 220°. Thus, a large portion of the surroundings of the motor vehicle may be detected but the very wide-angle lenses provide images with a large extend of distortion, and US '544 does not disclose if the distortion is corrected. In US '544 all sensors emit the sensed information to a single controller.
[0008] Tracking a detected pedestrian over time enables the system to detect a pedestrian at a relatively far distance from the vehicle, such as 15 meters or more, and then track the detected pedestrian with high confidence at a closer range, which might endanger the pedestrian and thus, the powered industrial vehicle driver will be warned by the system. Tracking also enables the system to stay locked on a detected pedestrian as the image of a detected pedestrian departs from a frame provided by one camera and enters a frame of an adjacent camera of the same system. Tracking of the detected pedestrian will then proceed using the second camera.
[0009] There are prior art systems, mounted in vehicles, for detecting pedestrians and for measuring the distance from the vehicle to the detected pedestrian. A pedestrian detection system is described in U.S. application Ser. No. 10/599,635 (hereinafter U.S. Ser. No. '635) by Shashua et al, the disclosure of which is included herein by reference for all purposes as if entirely set forth herein. U.S. Ser. No. '635 provides a system mounted on a host vehicle and methods for detecting pedestrians in an image frame, the image provided by a monocular camera.
[0010] A distance measurement from a visible camera image frame is described in “Vision based ACC with a Single Camera: Bounds on Range and Range Rate Accuracy” by Stein et al., presented at the IEEE Intelligent Vehicles Symposium (IV2003), the disclosure of which is incorporated herein by reference for all purposes as if entirely set forth herein. Distance measurement is further discussed in U.S. application Ser. No. 11/554,048 (hereinafter U.S. Ser. No. '048) by Stein et al., the disclosure of which is included herein by reference for all purposes as if entirely set forth herein. U.S. Ser. No. '048 provides methods for refining distance measurements from the vehicle hosting the distance measuring system, to an obstruction.
[0011] An obstruction detection and tracking system is described in U.S. Pat. No. 7,113,867 (hereinafter U.S. Pat. No. '867) by Stein, and included herein by reference for all purposes as if entirely set forth herein. Obstruction detection and tracking is performed based on information from multiple images captured in real time using a camera mounted in a vehicle hosting the obstruction detection and tracking system.
[0012] The systems disclosed in U.S. Ser. No. '635, U.S. Pat. No. '867 and U.S. Ser. No. '048, are typically part of a warning and/or control system for vehicles that are typically traveling forward on roads at relatively high speeds. They are not suitable to a powered industrial vehicle, such as a forklift, which typically travels off the road, at low speeds and in any directions. Thus, a powered industrial vehicle needs a warning system that can warn the driver of a pedestrian located anywhere near in the area around the powered industrial vehicle.
[0013] Thus, there is a need for and it would be advantageous to have a system including multiple cameras mounted on a powered industrial truck, each camera equipped with an image processing system for detecting pedestrians and in the system when one camera detects a pedestrian and the pedestrian moves out of the field of view (in horizontal plane) of the one camera, data is passed to the second camera so that the pedestrian is tracked using the multiple cameras over a wide field of view.
[0014] The term “powered industrial vehicle” as used herein refers to a vehicle selected from the group of vehicles including forklifts, container handlers, rubber tired gantry cranes. A powered industrial vehicle typically travels at a low speed, is capable of moving in multiple directions and frequently changes the traveling direction.
[0015] The term “Field Of View” (FOV) in general is the angular extent of a given scene, delineated by the angle of a three dimensional cone that is imaged onto an image sensor of a camera, the camera being the vertex of the three dimensional cone. The FOV of a camera at particular distances is determined by the focal length of the lens: the longer the focal length, the narrower the field of view. The terms “Field Of View” of a camera and “viewing zone” of a camera are used herein interchangeably and are used herein to refer to the horizontal angular extent of a given scene, as imaged on to the image sensor of the camera. It is assumed that the dimensions of the detector are adapted to the camera FOV.
SUMMARY OF THE INVENTION
[0016] According to the present invention there is provided a system mounted on a powered industrial vehicle for detecting classifying and tracking in real time at least one obstruction in the scene around the vehicle and method of use. The vehicle is capable of moving in multiple directions. The system includes multiple cameras mounted on the vehicle, wherein the viewing zones viewed respectively by the cameras preferably encompass 360° horizontally around the vehicle. Each of the cameras is operatively attached to an image processor, which processes the image frames acquired by the respective camera. When a pedestrian is present in the viewing zone viewed by one of the cameras, the image processor attached to the one camera identifies in at least one of the image frames at least a portion of an image of the detected pedestrian, thereby producing a detected pedestrian data object. The detected pedestrian data object includes one or more of the following features: distance, azimuth angle, size, time, color. The image processor computes the distance from the vehicle to the detected pedestrian and the azimuth to the detected pedestrian relative to the longitudinal axis of the vehicle. From a one time calibration procedure, the distance of each camera from the closest track external surface is measured and stored in the respective image processor and/or in the system processor. From a one time calibration procedure, the azimuth each camera optical axis relative to the longitudinal axis of the vehicle is measured and stored in the respective image processor and/or in the system processor.
[0017] The image processor continuously tracks the detected pedestrian while updating the computed distance from the vehicle to the detected pedestrian and the azimuth to the detected pedestrian relative to the longitudinal axis of the vehicle. The image processor transfers the detected pedestrian data object to a common bus interconnecting all image processors and the system processor wherein the image processor attaches an ID code to the detected pedestrian data object. Adjacent image processors can either read the detected pedestrian data object directly from the bus or receive it from the system processor.
[0018] Viewing zones of adjacent cameras are preferably overlapping. When the detected pedestrian enters an overlapping zone, i.e., the pedestrian is imaged by two adjacent cameras, respective image processors detect the obstruction, classify the obstruction as a pedestrian, measure the distance and azimuth to the detected pedestrian and continuously track the detected pedestrian. The system processor performs stereo analysis to refine the distance estimation to the detected pedestrian. The system processor notifies the vehicle operator interface on each detected pedestrian. The notification can be visual: lights, colored lights, display; and/or the notification can be audible: speakers. The speakers can be configured in a stereophonic configuration or in a surround configuration, indicating to the vehicle operator the direction to said detected pedestrian. The audible alarm to the operator is either constant in tone and/or loudness, or with a progressive increase in loudness and/or frequency as the pedestrian's proximity to vehicle decreases. The visual warning scheme can include, for example, indicating lights that turn from green to amber and from amber to red, as the pedestrian's proximity to vehicle decreases.
[0019] In embodiments of the present invention, an activation mechanism is operatively attached to the system processor, the activation mechanism causing the vehicle to slow down or stop, to avoid an accident.
[0020] In embodiments of the present invention, the system processor and one of the image processors are operated from a single processor.
[0021] In another method of the present invention, tracking of a detected pedestrian is performed by the system processor. This requires a higher frame rate transfer on the bus, when a pedestrian is detected.
[0022] In another method of the present invention, detection, classification and tracking of a detected pedestrian is performed by the system processor. This requires a much higher frame rate transfer on the bus, when a pedestrian is detected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The present invention will become fully understood from the detailed description given herein below and the accompanying drawings, which are given by way of illustration and example only and thus not limitative of lie present invention.
[0024] FIG. 1 is a perspective view of an embodiment of a pedestrian detection and tracking system of the present invention, configured with a powered industrial vehicle (in this case, a forklift vehicle).
[0025] FIG. 2 is a schematic illustration of a system pedestrian detection with N cameras, according with embodiments of the present invention;
[0026] FIG. 3 is a top view of an embodiment of a pedestrian detection and tracking system of the present invention configured with a forklift vehicle and a four cameras system, illustrating the viewing zones in which each camera is viewing, each viewing zone is delineated by the 90° FOV of the respective camera;
[0027] FIG. 4 is a top view of an embodiment of a pedestrian detection and tracking system of the present invention configured with a forklift vehicle and a six cameras system, illustrating the viewing zones in which each camera is viewing;
[0028] FIG. 5 is a top view of an embodiment of a pedestrian detection and tracking system of the present invention configured with a forklift vehicle and a six cameras system in a non-concentric configuration, illustrating the viewing zones viewed by each camera;
[0029] FIG. 6 is a top view of an embodiment of a pedestrian detection and tracking system of the present invention configured with a forklift vehicle and a six cameras system, illustrating the viewing zones in which each camera is viewing, the six cameras encompassing two separate zones;
[0030] FIG. 7 is a top view of a pedestrian detection and tracking system of the present invention illustrating a example of a viewing zone viewed by a camera 50 b , having a pedestrian 90 in the viewing zone;
[0031] FIG. 8 is a view of an image on an image plan of the camera 50 b , as illustrated in FIG. 7 ;
[0032] FIG. 9 is a conceptual view of the operator interface/control according with embodiments of the present invention;
[0033] FIG. 10 is a schematic flow diagram of a method 200 for detecting a pedestrian, in a pedestrian detection and tracking system mounted on a powered industrial vehicle, according with embodiments of the present invention;
[0034] FIG. 11 is a schematic flow diagram of a method 300 for detecting a pedestrian, in a pedestrian detection and tracking system mounted on a powered industrial vehicle, according with embodiments of the present invention;
[0035] FIG. 12 is a schematic flow diagram of a method 301 for detecting a pedestrian, in a pedestrian detection and tracking system mounted on a powered industrial vehicle, according with embodiments of the present invention;
[0036] FIG. 13 a illustrates a distorted image of a checkerboard pattern, as imaged through a 90° fisheye lens, used by a camera according to embodiments of the present invention;
[0037] FIG. 13 b illustrates the corrected image of the checkerboard pattern image of FIG. 13 a , as corrected by a system of the present invention;
[0038] FIG. 14 a illustrates a distorted image of a scene, as imaged through a 90° fisheye lens, used by a camera according to embodiments of the present invention; and
[0039] FIG. 14 b illustrates the corrected image of the scene image of FIG. 14 a , as corrected by a system of the present invention;
DETAILED DESCRIPTION OF THE INVENTION
[0040] The present invention is of a system mounted on a powered industrial vehicle and methods for detecting and classifying in real time an obstruction, in particular a pedestrian, around the powered industrial vehicle. The pedestrian detection and tracking system includes multiple cameras that combine to encompass the scene around the powered industrial vehicle, each camera equipped with an independent image processor. The pedestrian detection system and methods detect pedestrians in a series of image frames obtained from each camera.
[0041] The principles and operation of a system and method for detecting, classifying and tracking in real time a pedestrian, in a series of images obtained from a series of cameras mounted on a powered industrial vehicle to provide a signal to warn the vehicle operator of the detected a pedestrian, according to the present invention, may be better understood with reference to the drawings and the accompanying description.
[0042] Before explaining embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of design and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
[0043] By way of introduction, a principal intention of the present invention is to provide a system and method for detecting a pedestrian, preferably in an angle 360° around the vehicle. The pedestrian detection and tracking system includes a multiple number of cameras, each with a wide angle lens, that combine to encompass the scene around the vehicle, up to a range of 15 meters and more. Each camera FOV is at least tangential to the FOV of the next neighboring camera and preferable has some overlap with the FOV of the next neighboring camera. In some embodiments of the present invention, the image processing system of each camera is capable of correcting fisheye distortion of the camera lens and then detecting a pedestrian if the pedestrian appears in one or more viewing zones of the system cameras, and track the detected pedestrian over time. Tracking is maintained even if the detected pedestrian sits bends down or lies down on the floor. Tracking is maintained when the image of a detected pedestrian departs from a frame provided by one camera and enters a frame of the next neighboring camera. Tracking of the detected pedestrian will then proceed using the second camera. Upon detection of a pedestrian by the system and/or when the range of the detected pedestrian to the powered industrial vehicle is below some threshold, the driver of the vehicle is notified.
[0044] Implementation of the method and system of the present invention involves performing or completing selected tasks or steps manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of preferred embodiments of the method and system of the present invention, several selected steps could be implemented by hardware or by software on any operating system of any firmware or a combination thereof. For example, as hardware, selected steps of the invention could be implemented as a chip or a circuit. As software, selected steps of the invention could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system. In any case, selected steps of the method and system of the invention could be described as being performed by a data processor, such as a computing platform for executing a plurality of instructions.
[0045] Referring now to the drawings, FIG. 1 is a perspective view of an embodiment of a pedestrian detection and tracking system of the present invention configured with a powered industrial vehicle 10 (e.g. a forklift vehicle) and six camera units ( 50 and 60 ) viewing the scene in an angle 360° horizontally around the vehicle. The number of six cameras is given by way of example only, and the total number of cameras may vary depending on vehicle size, camera field of view, etc. Forklift 10 (with forks 40 being in the front of the vehicle) also includes an operator system interface that is typically located in dashboard 20 of vehicle 10 , behind wheel 22 .
[0046] Referring now to FIG. 2 , a schematic illustration of a pedestrian detection and tracking system 100 with N camera units ( 57 and 60 ), according to embodiments of the present invention, is shown. System 100 also includes a processor 120 and a vehicle operator interface 30 . Each camera unit 57 includes an image sensor or camera 571 , such as a CMOS sensor, and a processor 573 . Image frames 572 are captured by camera 571 . Methods according to different embodiments of the present invention analyze in real time image frames 572 , using either processor 573 or processor 120 to detect one or more obstructions in image frames 572 and classify the detected obstructions as pedestrians. The detected pedestrian are then tracked over time, as long as a pedestrian is in the FOV of at least one camera. Processor 120 and processor 573 are a general purpose microprocessor, a processor implemented using digital signal processing (DSP) or an application specific integrated circuit (ASIC) or a combination of the different technologies.
[0047] It should be noted that a one time calibration procedure is performed when the cameras 50 and 60 are installed on vehicle 10 . From a one time calibration procedure, the distance of each camera from the closest track external surface is measured and stored in the respective image processor and/or in the system processor. From a one time calibration procedure, the azimuth each camera optical axis relative to the longitudinal axis of the vehicle is measured and stored in the respective image processor and/or in the system processor.
[0048] All N camera units ( 57 and 60 ) can communicate with each other and with system processor 120 , preferably over a common system data bus 70 , e.g. CAN bus, USB bus, etc. In embodiments where digitized video signals are to be transferred to system processor 120 at a high frame rate, the selected bus should be of high bandwidth. Each camera unit 57 has an identification code (ID) and all messages a camera unit 57 transmits, includes the camera's ID. Optionally, each processor 573 of camera unit 57 is programmed to which camera ID to ‘listen’ to. For example, each camera unit 57 can be programmed to ‘listen’ only to the two adjacent cameras, in order to enable the performance of continuous tracking of a detected pedestrian.
[0049] System processor 120 includes a camera control unit 122 which coordinates the communication with each camera unit 57 and the inter communication among camera units 57 . System processor 120 may also include a pedestrian detector 124 and an obstruction detector 126 , which are used in a method in which detection and tracking of a pedestrian are not performed by the local image processor 573 . System processor 120 may also includes a warning/control unit 128 which issues warnings to the vehicle operator and/or control the vehicle controls, e.g. the track braking system. System processor 120 is preferably connected directly to back pointing camera 60 or to front pointing camera 50 . System processor 120 may also be integrated with one of the local image processor 573 , preferably with back pointing camera 60 or front pointing camera 50 .
Multiple Camera Configurations Examples
[0050] Referring now to FIG. 3 , a top view of an embodiment of a pedestrian detection and tracking system 100 of the present invention, configured with a forklift vehicle 10 and a four concentric cameras system, is shown. The viewing zones which each camera is viewing are delineated by the FOV of the respective camera: back pointing camera 60 has a FOV 601 , front pointing camera 50 a has a FOV 501 a , right pointing camera 50 b has a FOV 501 b and left pointing camera 50 c has a FOV 501 c . In the embodiment illustrated in FIG. 3 , FOVs 601 and 501 combine to encompass 360° horizontally around vehicle 10 with generally no overlap between adjacent FOVs. The preferred FOV of each camera 571 , in a four camera configuration, is 90°, but the present invention is not limited to a 90° FOV, and any FOV angle can be used.
[0051] Referring now to FIG. 4 , a top view of an embodiment of a pedestrian detection and tracking system 100 of the present invention configured with a forklift vehicle 10 and a six concentric cameras system, are shown. The viewing zones which each camera is viewing are delineated by the FOV of the respective camera: back pointing camera 60 has a FOV 601 , front pointing camera 50 a has a FOV 501 a , right pointing cameras 50 b and 50 d has a FOV 501 b and 501 d and left pointing cameras 50 c and 50 c has a FOV 501 e and 501 e . In the embodiment illustrated in FIG. 4 FOVs 501 and 601 combine to encompass 360° horizontally around vehicle 10 with a 30° overlap between adjacent FOVs. The preferred FOV of each camera 571 , in a four camera configuration, is 90°, but the present invention is not limited to a 90° FOV, and any FOV angle can be used.
[0052] Placing N cameras in a concentric configuration is often not practical on a powered industrial vehicle, which typically has only partial housing and partial roofing. The cameras need to be placed at location such that no or minimal blocking of field of vision of a camera occur. Each camera is preferably housed in a permanent structure and placed in a protective location due to the working conditions of and around the powered industrial vehicle. Hence, the cameras are typically placed in a non-concentric configuration. FIG. 5 is a top view of an embodiment of a pedestrian detection and tracking system 100 of the present invention configured with a forklift vehicle 10 and a six cameras system in a non-concentric configuration. The viewing zones which each camera is viewing are delineated by the FOV of the respective camera: back pointing camera 60 has a FOV 601 , front pointing camera 50 a has a FOV 501 a , right pointing cameras 50 b and 50 d has a FOV 501 b and 501 d and left pointing cameras 50 c and 50 c has a FOV 501 e and 501 e . Each adjacent pair of viewing zones overlap is reduced to about 2°. Some blind spots 80 maybe formed. Blind spots 80 are limited in range to a few feet. In the example shown in FIG. 5 of a pedestrian detection and tracking system 100 with a four camera configuration, the FOV of each camera 571 , is 90°, but the present invention is not limited to a 90° FOV, and any FOV angle can be used.
[0053] The present invention preferably encompasses 360° horizontally around vehicle 10 with an overlap between adjacent FOVs. But in some embodiments of the present invention, pedestrian detection and tracking system 100 may encompass and area horizontal angle less than 360°. FIG. 6 is a top view of an embodiment of a pedestrian detection and tracking system 100 of the present invention configured with a forklift vehicle 10 and a six cameras system, illustrating the viewing zones in which each camera is viewing, the six cameras encompassing two separate zones. This configuration is given by way of example only and other configurations encompass and area horizontal angle less than 360° are possible and are within the scope of the present invention.
Vehicle Operator Interface
[0054] Pedestrian detection and tracking system 100 also includes a vehicle operator interface unit 30 , which is typically located in dashboard 20 of vehicle 10 , behind wheel 22 . FIG. 9 is an example illustration of a vehicle operator interface/control 30 according to embodiments of the present invention. Interface 30 may include visual and/or audible indication to alert the operator on the presence of a pedestrian in the vicinity of vehicle 10 . In the example of FIG. 9 , interface 30 includes a display 32 presenting the cameras viewing zones, and light indicators 34 , for example green red and amber, indicating the danger level to a detected pedestrian in vehicle 10 vicinity. When a pedestrian is detected, the corresponding zone of display 32 , representing the zone around vehicle 10 in which the pedestrian is located, may, for example, turn on, change color or provide any other type of indication.
Methods of the Present Invention
[0055] Referring back to FIG. 2 and also referring now to FIG. 10 , which is a schematic flow diagram of a method for detecting a pedestrian, in a pedestrian detection and tracking system 100 mounted on a powered industrial vehicle 10 , according with embodiments of the present invention. In method 200 , when vehicle 10 is operated, pedestrian detection and tracking system 100 starts monitoring the scene in an angle 360° horizontally around vehicle 10 (step 210 ) with N camera units ( 57 and 60 ). Upon the entering of a pedestrian into a zone viewed by an image sensor 571 of camera unit 57 , the image frames 572 , which include the images of the pedestrian, are transmitted to respective image processor 573 . Image processor 573 analyzes image frames 572 and detects the pedestrian (step 220 ), thereby producing a detected pedestrian. The distance and azimuth from vehicle 10 to the pedestrian are computed (step 222 ) and system processor 120 is notified (step 260 ). System processor 120 in turn notifies the vehicle operator and possibly other bodies, such as a control center (step 270 ). Image processor 573 tracks the detected pedestrian (step 224 ), using camera unit 57 , while continuing computing the distance and azimuth from vehicle 10 to the detected pedestrian. The two adjacent camera units 57 are notified by system processor 120 about the detected pedestrian being detected tracked by camera unit 57 .
[0056] Upon the entering of the pedestrian also into a zone viewed by the image sensor of a camera unit adjacent to camera unit of camera unit 57 , image processor 573 of the adjacent camera unit 57 analyzes respective image frames 572 received from image processor 573 of the adjacent camera unit 57 . Image processor 573 of the adjacent camera unit 57 detects the pedestrian (step 230 ), thereby also producing a detected pedestrian data object. The distance and azimuth from vehicle 10 to the pedestrian are computed (step 232 ) and system processor 120 is notified (step 260 ). Image processor 573 of the adjacent camera unit 57 starts tracking the detected pedestrian (step 234 ), using the adjacent camera unit 57 , while continuing computing the distance and azimuth from vehicle 10 to the detected pedestrian. When there is an overlap of the zone viewed by the image sensor of a camera unit 57 and the zone viewed by the image sensor of the adjacent camera unit 57 , stereo analysis is performed by system processor 120 to refine the distance estimation to the twice detected pedestrian (step 240 ). The results of the stereo analysis are synchronized by system processor 120 with the image processors 573 of the two camera units 57 . When the pedestrian drops out of the zone viewed by one of the image sensors 571 , tracking proceeds using the other camera unit 57 (step 260 ). As tracking continuous and the distance and/or azimuth to the detected pedestrian are changing, system processor 120 is notified and in turn, the vehicle operator is updated (step 270 ). In the following description, method steps of method 200 are discussed in further detail.
[0057] Step 210 : Monitor the scene in an angle 360° horizontally around the vehicle.
[0058] A power industrial vehicle 10 is typically a vehicle that can travel in any direction and rapidly change the direction of travel. But the operator of vehicle 10 stays in the same orientation, relative to vehicle 10 , not being able to continuously view all the area around vehicle 10 , a set of cameras are positioned on vehicle 10 to continuously monitor the scene in an angle 360° horizontally around vehicle 10 , up to a range of 15 meters and more, using N camera units ( 57 and 60 ). In a preferred embodiment, six camera units are used (N=6). Camera units ( 57 and 60 ) are positioned in a protected location in the periphery of vehicle 10 . Viewing zones of adjacent cameras 50 preferably overlap in horizontal angle and at least tangential. In a non-concentric six camera configuration, each camera 50 preferably has a 90° FOV and the viewing zones overlap of about 20° in horizontal angle.
[0059] Step 220 : Detect pedestrian by camera unit 57 .
[0060] Upon the entering of a pedestrian into a viewing zone viewed by an image sensor 571 of camera unit 57 , image frames 572 including the pedestrian image are transmitted to respective image processor 573 . Image processor 573 analyzes image frames 572 and detects the pedestrian, thereby producing a detected pedestrian data object. Detection is made at a distance ranging from 1.5 meters and up to 15 meters and more. At a distance below 10 meter, not the whole body of a pedestrian is in the viewing zone of a camera.
[0061] Step 222 : Compute distance and azimuth to pedestrian.
[0062] Image processor 573 computes the distance from vehicle 10 to the detected pedestrian. U.S. Ser. No. '048 provides methods for computing and refining distance measurements from a vehicle hosting the distance measuring system, to an obstruction, including pedestrians. FIG. 7 is a top view of a pedestrian detection and tracking system 100 of the present invention illustrating an example of a viewing zone viewed by the image sensor of camera unit 50 , having a pedestrian 90 in the viewing zone. FIG. 8 is a view of a corrected image 450 on an image plan of image sensor of camera unit 50 , as illustrated in FIG. 8 . Image 450 includes a detected pedestrian 490 with a rectangle 492 enclosing detected pedestrian 490 . Each image processor 573 knows the distance of respective image sensor of camera unit 50 from the local external surface of vehicle 10 and computes the distance to the bottom of rectangle 492 . Distance measurement is performed as described in U.S. Ser. No. '048. Image processor 573 also knows the azimuth φ of the optical axis of image sensor of camera unit 50 and the pixel P(x j , y j ) which represents the optical axis in image 450 . The azimuth θ to pedestrian 90 is computed from the displacement d in the image of detected pedestrian 490 relative to P(x j , y j ) and from the known angle φ between the optical axis 52 b of the image sensor of camera unit 50 and the longitudinal axis 12 of vehicle 10 .
[0063] Step 224 : Track detected pedestrian 490 and monitor distance.
[0064] Pedestrian tracking is performed as described in U.S. Pat. No. '867. Image processor 573 continuously tracks detected pedestrian 490 in image 450 as the image of detected pedestrian 490 changes the position inside image 450 , as both pedestrian 90 and vehicle 10 are changing the spatial positions. As pedestrian 90 and vehicle 10 are changing spatial positions, image processor 573 continuously re-computes the distance from vehicle 10 to pedestrian 90 and the azimuth to pedestrian 90 relative to vehicle 10 . Although detection is not ensured when the distance of a pedestrian 90 form vehicle 10 is below 1.5 meters, but tracking is maintained down to a distance of at least 1 meter.
[0065] Tracking is maintained even if pedestrian 90 sits down, bends down or lies down on the floor. Tracking is also maintained when the image of a detected pedestrian 490 departs from an image frame 572 provided by an image sensor 571 and enters the image frame 572 of the next neighboring camera 571 . Tracking of the detected pedestrian 490 will then proceed using the second image sensor 571 .
[0066] Step 230 : Detect pedestrian by a neighbor camera unit.
[0067] When a pedestrian 90 enters a zone viewed by a second adjacent image sensor, image processor 573 of the adjacent camera unit 57 analyzes respective image frames 572 and detects pedestrian 490 as was done by image processor 573 in step 220 .
[0068] Step 232 : Compute distance and azimuth to pedestrian by the neighbor camera unit.
[0069] Image processor 573 of neighbor camera unit 57 computes the distance and azimuth to pedestrian 90 as was done by image processor 573 in step 222 .
[0070] Step 234 : Track detected pedestrian 490 and monitor distance by the neighbor camera unit.
[0071] Image processor 573 of neighbor camera unit 57 continuously tracks and re-computes the distance and azimuth to pedestrian 90 as was done by image processor 573 in step 224 .
[0072] Step 240 : Refine distance estimation using stereo analysis.
[0073] When a pedestrian 90 enters a zone viewed by two adjacent image sensors 571 , image processor 573 employs stereo analysis to refine the measured distance from the external surface of vehicle 10 to pedestrian 90 . The stereo analysis to refine the distance estimation to the twice detected pedestrian (step 240 ), is performed by system processor 120 . The results of the stereo analysis are synchronized by system processor 120 and image processors 573 performing the detection and tracking.
[0074] Step 250 : Continue tracking by the neighboring camera unit.
[0075] When a pedestrian 90 departs the zone viewed image sensor 571 and remains only in the zone viewed by adjacent image sensor 571 , only the respective image processor 573 continuous to track and to re-computes the distance and azimuth to pedestrian 90 .
[0076] Step 260 : Notify system processor.
[0077] When an image processor 573 detects an obstruction and classifies the obstruction as a pedestrian 90 , image processor 573 notifies on the detected pedestrian 490 to system processor 120 . The notification message also includes an identification code, to enable system processor 120 to identify the sending camera unit 57 . System processor 120 prepares the two adjacent camera units 57 for the possibility that pedestrian 90 will enter the camera units 57 viewing zones. System processor 120 is updated when tracking of a detected pedestrian 490 is established or stopped. System processor 120 is also continuously updated as to the distance and azimuth from the external surface of vehicle 10 to pedestrian 90 .
[0078] Step 270 : Notify the vehicle operator, control center.
[0079] When an image processor 573 detects pedestrian 90 and notifies system processor 120 , system processor 120 notifies the vehicle operator by activating the proper indicators in operator interface 30 , the indicators being visual and/or audible. The notification to the vehicle operator may be performed according to a pre-designed warning schemer, e.g., the audible alarm to the operator is either constant in tone and loudness, or with a progressive increase in loudness and frequency as the pedestrian's 90 proximity to vehicle 10 decreases. The visual warning scheme can include, for example, indicating lights that turn from green to amber and from amber to red, as the pedestrian's 90 proximity to vehicle 10 decreases. The audio warning can be stereophonic, or surround or directional in any other way, such that it indicates the relative position of the detected pedestrian.
[0080] It should be noted that system processor 120 may not only notify the vehicle operator but also operate controls of vehicle 10 , e.g. activate vehicle 10 brakes and/or reduce engine power, to avoid an accident.
[0081] Reference is also now made to FIG. 11 , which is a schematic flow diagram of a method for detecting a pedestrian 90 , in a pedestrian detection and tracking system 100 mounted on a powered industrial vehicle 10 , according with other embodiments of the present invention. It should be noted that in order for method 300 to perform in real time, bus 70 (see FIG. 2 ) must accommodate the required transferred rate of video images from processors 573 to system processor 120 .
[0082] In method 300 , when vehicle 10 is operated, pedestrian detection and tracking system 100 starts monitoring the scene in an angle 360° horizontally around vehicle 10 (step 310 ). Upon entering of a pedestrian 90 into a zone viewed by an image sensor 571 of camera unit 57 (step 320 ), respective image processor 573 analyzes respective image frames 572 and detects the pedestrian 490 (step 330 ), thereby producing a detected pedestrian data object. Optionally, image processor 573 also computes the distance and azimuth from vehicle 10 to detected pedestrian 490 (step 340 ).
[0083] The detected pedestrian data object, which may include the images including detected pedestrian 490 , computed distance and azimuth aid camera unit 57 ID, are transmitted by image processor 573 to system processor 120 (step 350 ). The distance and azimuth from vehicle 10 to pedestrian 90 are computed (step 360 , if not computed in step 340 ). The vehicle operator and/or other bodies, such as a control center, are then notified (step 390 ). System processor 120 starts tracking the detected pedestrian 490 (step 370 ), using camera unit 57 , while continuing computing the distance and azimuth from vehicle 10 to pedestrian 90 (step 360 ). Any change in distance or azimuth is reported (step 390 ).
[0084] The two adjacent camera units 57 are notified by system processor 120 that detected pedestrian 490 is being tracked, using camera unit 57 . Upon entering of pedestrian 90 into a zone viewed by a neighboring camera unit of camera unit 57 (step 322 ), respective image processor 573 analyzes respective image frames 572 and detects the pedestrian 490 (step 332 ), thereby producing a detected pedestrian data object. Optionally, image processor 573 also computes the distance and azimuth from vehicle 10 to detected pedestrian 490 (step 342 ). The detected pedestrian data object is transmitted by image processor 573 to system processor 120 (step 350 ).
[0085] System processor 120 performs stereo analysis to refine the distance estimation to the detected pedestrian 490 (step 380 ). When pedestrian 90 drops out of the zone viewed by image sensor 571 , tracking proceeds using the adjacent camera unit 573 (step 370 ), which pedestrian 90 is in the respective image sensor 572 viewing zone. As tracking continuous and the distance and/or azimuth to pedestrian 90 are changing, the vehicle operator is updated (step 390 ).
[0086] Reference is also now made to FIG. 12 , which is a schematic flow diagram of a method for detecting a pedestrian 90 , in a pedestrian detection and tracking system 100 mounted on a powered industrial vehicle 10 , according with other embodiments of the present invention. It should be noted that in order for method 301 to perform in real time, bus 70 (see FIG. 2 ) must accommodate the required transferred rate of video images from processors 573 to system processor 120 .
[0087] In method 301 , when vehicle 10 is operated, pedestrian detection and tracking system 100 starts monitoring the scene in an angle 360° horizontally around vehicle 10 (step 311 ). Upon entering of a pedestrian 90 into a zone viewed by an image sensor 571 of camera unit 57 (step 321 ), the image frames 572 , which include the images of pedestrian 90 , are transmitted by respective processor 573 to system processor 120 (step 341 ). System processor 120 analyzes image frames 572 and detects the pedestrian (step 351 ), thereby producing a detected pedestrian. The distance and azimuth from vehicle 10 to pedestrian 90 are computed (step 361 ) and the vehicle operator and/or other bodies, such as a control center, are notified (step 391 ). System processor 120 starts tracking the detected pedestrian 490 (step 371 ), using camera unit 57 , while continuing computing the distance and azimuth from vehicle 10 to pedestrian 90 . Any change in distance or azimuth is reported (step 391 ). The two adjacent camera units 57 are notified by system processor 120 that detected pedestrian 490 is being tracked, using camera unit 57 . Upon entering of pedestrian 90 into a zone viewed by a neighboring camera unit of camera unit 57 , stereo analysis is used to refine the distance estimation to the detected pedestrian 490 (step 381 ). When pedestrian 90 drops out of the zone viewed by image sensor 571 , tracking proceeds using the adjacent camera unit 573 (step 371 ) which pedestrian 90 is in the respective image sensor 572 viewing zone. As tracking continuous and the distance and/or azimuth to pedestrian 90 are changing, the vehicle operator is updated (step 391 ).
Distortion Correction
[0088] In order to be able to continuously monitor the scene in an angle 360° horizontally around vehicle 10 , pedestrian detection and tracking system 100 of the present invention utilizes N camera unit 57 , where in the preferred embodiment, N=6 Still, to maintain some overlap between viewing zones formed by the FOV of each adjacent pair of cameras, a 90° FOV is needed. A 90° FOV implies using wide-angle lenses which deform the images obtained by the camera by a large extend of distortion.
[0089] Reference is now made to FIGS. 13 a and 13 b . FIG. 13 a illustrates a distorted image 400 of a checkerboard pattern, as imaged through a 90° fisheye lens, used by a camera 571 according to embodiments of the present invention. FIG. 13 b illustrates the corrected image 401 of the checkerboard pattern of FIG. 13 a . The corrected image 401 of the checkerboard pattern demonstrates the extent of the distortion of the distorted image 400 of a checkerboard pattern. The corrected image 401 of the checkerboard pattern demonstrates the ability of pedestrian detection and tracking system 100 to correct the distortion.
[0090] Reference is also now made to FIGS. 14 a and 14 b . FIG. 14 a illustrates a distorted image 410 of a scene, as imaged through a 90° fisheye lens, used by a camera according to embodiments of the present invention. FIG. 14 b illustrates the corrected image 411 of the scene image of FIG. 14 a . Pedestrian 420 is tracked in the corrected image 411 , as illustrated by rectangle 422 . It should be noted the optical distortion is fixed per each individual system and needs to be measured only once in a system lifetime to derive its optical correction equation.
[0091] In embodiments of the present invention, pedestrian detection and tracking system 100 is mounted and operated on powered military vehicles.
[0092] In embodiments of the present invention, pedestrian detection and tracking system 100 is fused with a SONAR obstruction detection system, whereby the confidence of pedestrian detection is enhanced. The SONAR obstruction detection system comprises one or more ultrasonic transmitters and one or more sensors, whereas the fusion of information obtained from pedestrian detection and tracking system 100 and the SONAR obstruction detection system, is performed by either one or more processors 573 or by system processor 120 .
[0093] In embodiments of the present invention, pedestrian detection and tracking system 100 is fused with a FIR (Far Infra-Red) obstruction detection system, whereby the confidence of pedestrian detection is enhanced. The FIR obstruction detection system comprises one or more FIR image sensors, whereas the fusion of information obtained from pedestrian detection and tracking system 100 and the FIR obstruction detection system, is performed by either one or more processors 573 or by system processor 120 .
[0094] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact design and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
[0095] While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.
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A system mounted on a powered industrial vehicle for detecting classifying and tracking in real time at least one obstruction in the scene around the vehicle. The vehicle is capable of moving in multiple directions. The system includes a multiple cameras mounted on the vehicle, wherein the viewing zones viewed respectively by the cameras preferably encompass 360° horizontally around the vehicle. Each of the cameras is operatively attached to an image processor, which processes the image frames acquired respectively by the camera. When a pedestrian is present in the viewing zone viewed by one of the cameras, the image processor attached to the one camera identifies in at least one of the image frames at least a portion of an image of the detected pedestrian
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BACKGROUND OF THE INVENTION
[0001] 1. Field
[0002] The invention is concerned with the manufacture of an anisotropic layer of cross-linked liquid crystalline monomers (LCP) in contact with an orientating layer on a single substrate, and with optical components having a layered structure comprising an orientating layer, a LCP layer, and at least one additional orientating layer over the LCP layer on a single substrate and their preferred use.
[0003] 2. Description
[0004] Anisotropic transparent or colored cross-linked polymer layers with three-dimensional orientation of the optical axis, either uniform or preset at individual places, are of great interest in many sectors of display technology, integrated optics, etc.
[0005] For some years, substances having this property have become known, namely certain cross-linkable liquid crystalline diacrylates and diepoxides. These substances as monomers, that is before cross-linking, can be orientated in the liquid crystalline phase in sandwich cells consisting of, for example, glass plates having an interposed monomer layer with the aid of conventional orientating layers on the two glass plate surfaces or under the influence of external fields, such as strong magnetic or electric fields. In a second phase, the monomer layer can be photo-cross-linked in the cells such that the wall forces acting on the two sides of the monomer layer, or the applied fields, preserve the preset orientation during the cross-linking process.
[0006] These external mechanical, electrical or magnetic forces prevent thermodynamic orientation relaxation inherent in liquid crystals and counteract the de-orientating forces of conventional cross-linking processes. In the absence of these external forces a de-orientation or a re-orientation of the liquid crystals usually takes place. The re-orientation from planar to perpendicular at the interface to the atmosphere opposite the substrate surface has been shown in the case of single substrates, see Hikmet and de Witz, J. Appl. Phy. 70:1265-1269 (1991). (Throughout the specification, documents have been identified. The contents of each of these documents are herein incorporated by reference).
[0007] Layer structures of liquid crystalline polymers are known, see EP-A-331 233. They are manufactured by orientating a monomer layer in a cell with a voltage applied to the cell plates and then irradiating in a partial region through a mask. By so doing, cross-linking is initiated in the irradiated region only. Subsequently, the direction of the external field is changed and the monomer regions which have not yet been cross-linked are re-orientated with respect to the new field direction. Thereupon, the latter region is also illuminated and thus cross-linked. Clearly, this method cannot yield an orientating structure with high local resolution, since the radical cross-linking reaction, owing to the shading of the mask, does not have sharp boundaries. Further, this method is invariably limited to the use of sandwich cells for orientating the layer structure in an electric field.
[0008] Recently, there have become known methods which permit the production of orientating layers with locally variable orientating properties. The orientation of dichroic dye molecules incorporated in the polymer with the aid of photolithographic methods is described in U.S. Pat. No. 4,974,941, the contents of which are herein incorporated by reference.
[0009] The orientability and photo-structurability of a liquid crystalline monomer layer in a sandwich cell, the two surfaces of which have been photo-orientated by the laser orientation process described in U.S. Pat. No. 4,974,941, has also recently become known. This process is also limited to orientation of the monomer layer in a cell. The orientation impressed by the cell surfaces is frozen by subsequent conventional photopolymerization of the liquid crystalline monomer layer in the cell. In order to obtain a coated single substrate, the cell must be dismantled after the polymerization (P. J. Shannon, W. M. Gibbons, S. T. Sun, Nature, 368:532 (1994)).
[0010] The production of optical strongly anisotropic layers consisting of orientated liquid crystal polymers in cells is also known from Research Disclosure No. 337, May 1992, Emsworth, GB, pages 410-411. There, the manufacture of such layers by placing the liquid crystal monomer in the cell, orientating by means of the two cell walls via rubbed polyimide surfaces of the cell and subsequent conventional photopolymerization in the cell is described. Further, it is mentioned that one of the two glass plates can be removed after the polymerization step in order to thereby obtain a single glass substrate coated with LC polymer. This orientated substrate can, moreover, be provided with a polyimide layer having a new direction of orientation (by rubbing).
[0011] After again assembling the thus-prepared polymer substrate in a second orientated sandwich cell, filling this cell with a further monomer layer and subsequent conventional photopolymerization, the optical pitch differences of the two differently oriented LC polymer layers in the cell are added or subtracted.
[0012] Since the rubbing of the polyimide layers on the cell surfaces is a macroscopic process, no orientation pattern can be produced with this process, the cells being uniformly orientated over the entire surface. Further, it is extremely time consuming and expensive for the manufacturer of cells having precise plate separations for the realization of uniform optical pitch differences (in the ten nanometre range).
[0013] Where, optical retarder layers are required on a single substrate, the manufacture requires, as described in Shannon et al., dismantling the cell. In so doing, the retarder layer must not be damaged. This complicates the manufacturing process rendering it impractical, especially in the case of large substrate areas as are required for high-information computers and TV-LCDs.
[0014] Layer structures comprising a film of cross-linked liquid crystalline monomers in contact with an orientating layer of a photo-orientable polymer network (PPN) are described in European Application No. 0 611 981, published Aug. 24, 1994. The manufacture of these layer structures is effected by planar orientation of the liquid crystalline monomers by interaction with the PPN layer and fixing the orientation in a subsequent cross-linking step. Cross-linked liquid crystalline monomers are also referred to as LCPs (liquid crystal polymers) in the following text.
[0015] It has now surprisingly been found that liquid crystalline monomer layers can also be applied to and cross-linked on single substrate surfaces which already contain a LCP layer. For this purpose, neither a further orientating counter-substrate of a sandwich cell is required nor are magnetic fields or electric fields necessary for the orientation. This contrasts with EP-A-0 397 263, in which magnetic field orientation of dichroic dyes in a single LC monomer layer for the manufacture of a polarizing film is indicated as being preferred and is actually the sole exemplified process (field-free orientation is, indeed, claimed, but not demonstrated).
[0016] Furthermore, it has surprisingly been found that the orientation of these monomer layers on a single substrate is not influenced or destroyed by subsequent polymerization or photo-cross linking. Thus, it is for the first time possible to manufacture on single LCP-orientated substrate surfaces in a simple sequential manner solid films consisting of several orientated liquid crystalline polymer layers. Further, additional layers having different optical and/or electrical functions can be integrated in these complex hybrid layers. This offers for the first time the possibility of realizing not only known but also novel optical components such as polarization-interference filters, optical retarders, polarizers, etc. on single substrates by means of LCPs and to combine and to integrate these components in hybrid layers. Further, additional functional layers such as orientating layers for liquid crystals can be integrated in the hybrid layers.
[0017] The present invention provides and opens up new possibilities for optical and electro-optical components and devices using layer structures of the aforementioned kind.
SUMMARY OF THE INVENTION
[0018] The invention provides a process for making an isotropic layer of cross-linked liquid crystalline monomers in contact with an orientating layer on a single substrate. This process comprises applying an orientating layer onto a single substrate, then applying a layer of a non-cross-linked liquid crystalline monomer, and subsequently cross-linking the monomer. Also provided is an optical component having a layer structure. The component comprises a substrate, a first orientating layer, a liquid crystalline monomer layer, and a second orientating layer. The first and second orientating layers are located on opposite sides of the crystalline monomer layer. At least one of the orientating layers includes a photo-orientating polymer network.
[0019] The manufacture in accordance with the invention of an anisotropic layer of cross-linked liquid crystalline monomers (LCP) in contact with an orientating layer comprises applying an orientating layer on a single substrate and applying to this a layer of a non-cross- linked liquid crystalline monomer and subsequently cross-linking the monomer. For the manufacture of more complex layer structures, additional orientating and liquid crystal layers can be applied in further steps and these layers can be cross-linked. Moreover, if desired, optically isotropic de-coupling layers or electrically conducting layers can be inserted or applied between individual LCP layers under the following orientating layers.
[0020] The optical component according to the invention is characterized in that at least one of the orientating layers is a layer of a photo-orientating polymer network (PPN) or has a local varying orientating pattern.
[0021] Preferably, use is made of monomer mixtures which have nematic, cholesteric, ferroelectric or non-linear optical (NLO) activity at room temperature.
[0022] The second and other LCP layers can also be applied directly, i.e. without intermediate PPN layers, to the first.LCP layer and subsequently cross-linked. Thereby, the monomers in the second and subsequent layers take over the preferred orientation of the first or respective underlying LCP layers.
[0023] It will be appreciated that the PPN and LCP layers need not cover the entire surface of the substrate, but can cover all or part of the surface in individual and varying manner.
[0024] These multi-layer structures are used in optical and electro-optical devices, particularly in the manufacture of liquid crystal cells in which the various LCP layers serve different optical and orientating purposes. They are also used in integrated optical devices, e.g. in strip waveguides, Mach-Zender interferometers and frequency-doubling waveguide arrangements. Finally, these layer structures can be used as a safeguard against counterfeiting and copying.
BRIEF DESCRIPTION OF THE FIGURES
[0025] Embodiments of the invention will be described hereinafter with reference to the accompanying simplified diagrammatic drawings in which:
[0026] [0026]FIG. 1 shows a layer structure of an optical component according to the invention;
[0027] [0027]FIG. 2 shows a layer structure of an optical component with an additional layer;
[0028] [0028]FIG. 3 shows an alternative layer structure with an additional de-coupling layer;
[0029] [0029]FIG. 4 shows another layer structure with locally varying orientation of component regions;
[0030] [0030]FIG. 5 shows another layer structure as in FIG. 4, but with an additional de-coupling layer;
[0031] [0031]FIG. 6 shows a supertwisted nematic (STN) liquid crystal display cell with a layer structure according to FIG. 3;
[0032] [0032]FIG. 7 shows a diagram of the directions of the nematic director, the optical retarder layer and the polarizers in the cell according to FIG. 6; and
[0033] [0033]FIG. 8 shows an alternative liquid crystal cell with a layer structure according to FIG. 2, but with an additional ITO layer.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The subject invention will now be described in terms of its preferred embodiments. These embodiments are set forth to aid in understanding the invention, but are not to be construed as limiting.
[0035] The invention provides a process for making an isotropic layer of cross-linked liquid crystalline monomers in contact with an orientating layer on a single substrate. This process comprises applying an orientating layer onto a single substrate, then applying a layer of a non-cross-linked liquid crystalline monomer, and subsequently cross-linking the monomer. Also provided is an optical component having a layer structure. The component comprises a substrate, a first orientating layer, a liquid crystalline monomer layer, and a second orientating layer. The first and second orientating layers are located on opposite sides of the crystalline monomer layer. At least one of the orientating layers includes a photo-orientating polymer network.
[0036] [0036]FIG. 1 is a diagrammatic section through a layer structure in one embodiment of the invention, showing a substrate 1 of transparent or reflecting material such as glass, polymer, metal, paper, etc. A layer Z of a photo-orientated polymer network is disposed on the substrate and either covers the entire substrate uniformly or has varying local planar orientation. The layer can be made, for example, of cinnamic acid derivatives which are described and published in European Patent Applications Nos. 0 525 477 and 0 525 478.
[0037] The layer is orientated and simultaneously cross-linked by selective irradiation with linear polarized UV light.
[0038] Instead of the PPN layer, the layer 2 can also be a conventional orientating layer, for example a polyimide layer rubbed in one direction or a layer having an orientating effect and obtained by oblique sputtering with SiO x . In this case, the orientating layer will usually have uniform orientation over the entire substrate surface. In applications where uniform orientation over the entire surface is desired, this mechanical alternative may be less expensive to manufacture than a PPN layer.
[0039] The PPN layer 2 can, in turn, be applied to a conventionally orientated layer previously deposited on the substrate 1 , e.g. an obliquely sputtered SiO x layer or a uniformly rubbed polymer layer.
[0040] The layer 2 is adjacent an anisotropic layer 3 of orientated cross-linked liquid crystal monomers. The layer 3 has an arrangement of molecules having an orientation determined by the orientation of the underlying layer 2 or transferred therefrom to the liquid crystal layer. The LCP layer 3 is photo cross-linked by the action of light of suitable wavelength and retains the orientation of molecules predetermined by the layer 2 . The photo cross-linking fixes the orientation of the LCP layer 3 so that it is unaffected by extreme external influences such as light or high temperatures.
[0041] Even optical or thermal instabilities occurring in the course of time in the PPN layer Z will not adversely influence the orientating properties of the LCP layer 3 after cross-linking.
[0042] The LCP layer 3 is adjacent another orientating layer which, as before, is either a PPN layer or a conventional orientating layer depending on whether locally varying orientation patterns or a uniform orientation for an adjacent second LCP layer 5 according to FIG. 2 is desired. The LCP layer 5 is produced in the same manner and has the same properties as the layer 3 , but the two LCP layers are usually differently orientated.
[0043] [0043]FIG. 3 shows an embodiment of a component in which, as in the previously described case, two LCP layers with respective orientation layers are disposed on a substrate 1 . In contrast to the embodiment in FIG. 2, however, an optically isotropic or weakly anisotropic de-coupling layer 6 is disposed between the lower LCP layer 3 and the upper orientating layer 4 to prevent the LCP layer 3 exerting an orientating influence, which it of course also can have as a retarder layer, on the, upper hybrid layers 4 , 5 and consequently on a liquid crystal disposed above the layer 5 . The de-coupling layer 6 can be made, for example, of silicon oxides (SiO x ) or isotropic polymers such as polyvinyl alcohol (PVA) or nylon.
[0044] [0044]FIG. 4 shows a layer structure which, like FIG. 2, consists of four layers superposed on a substrate 1 , i.e. a first PPN layer 2 , a first LCP layer 3 , an additional PPN layer and an additional LCP layer. In contrast to the arrangement according to FIG. 2, however, the two upper layers have different local orientations. The PPN layer has regions 7 with a first orientation and regions 8 with a second orientation different from the first. Since the orientation is transmitted to the LCP layer before cross-linking thereof, the LCP layer has regions 9 with the first orientation and regions 10 with the second orientation.
[0045] Similarly, the layer structure shown in FIG. 5 corresponds to that of FIG. 3, i.e. with a decoupling layer, except that the upper PPN layer as before contains differently oriented regions 7 and 8 and the upper LCP layer contains regions 9 and 10 with correspondingly different orientation.
[0046] When a layer structure shown in FIGS. 1 - 5 and with two individually oriented LCP layers is used to produce a liquid crystal cell, the layer 3 can serve as a retarder and layer 5 or 9 , 10 can serve as the orientating layer for the liquid crystal. To obtain a retarder effect, the optical path difference of the LCP layer 3 is usually given a high value, i.e. above 100 nm.
[0047] [0047]FIG. 6 is a diagrammatic section through a liquid crystal cell constructed using a layer structure of this kind. A liquid crystal layer 15 lies between two glass plates 1 and 12 coated with a number of layers on their surfaces facing the liquid crystal. The plate 1 is firstly provided with an electrode layer 11 , preferably of indium tin oxide (ITO) for applying a voltage. In order to avoid voltage drops across the polymer layers, the ITO layer 11 may alternatively be applied over the layer 3 or 6 . In other respects the layer structure has the configuration shown in FIG. 3, i.e. two PPN-LCP combinations 2 , 3 and 4 , 5 with an alternately interposed de-coupling layer 6 . The LCP layer 3 serves as a retarder, whereas the LCP layer 5 orients the liquid crystal 15 . The substrate can also be provided with a reflective layer.
[0048] The other glass plate 12 is likewise coated with an ITO electrode layer 13 underneath an orientation layer 14 , e.g. of unidirectionally ground PVA.
[0049] In order to obtain an STN cell with an angle of rotation φ=240°, the orientation directions of the PVA layer 14 and of the top LCP layer 5 are at an angle of 60° to one another. The result, if the liquid crystal has suitable chiral doping, is a twist of 240° C. in the liquid crystal 15 . FIG. 7 shows the arrangement of polarizers P 1 and P 2, the direction of the slow optical axis c e of the optical retarder 3 , and the wall orientation directions {circumflex over (n)} i and {circumflex over (n)} 2 of the liquid crystal layer 15 adjacent the two orientation layers 5 and 14 . {circumflex over (n)} 1 and P 1 are on the retarder side.
[0050] This cell is opaque when no voltage is applied, but becomes transparent when actuated with a suitable voltage. Because of the incorporated retarder 3 , the usual interference colors in STN cells do not occur, i.e. the cell is white as regards optical visibility.
[0051] The retarder layer 3 can also consist of a liquid crystal mixed with chiral dopants. An angle of twist between 0° and 360° can be obtained by varying the concentration of dopant. The twisting can be levorotatory or dextrorotatory.
[0052] Twisted retarders of this kind are particularly suitable for color compensation of STN display cells. Preferably retarder layers with large optical path differences of Δn·d ≈900 nm are used for this purpose. When a twisted optical retarder is used in the STN cell of FIG. 6, the following conditions must be met:
[0053] The sense of rotation of the optical retarder is opposite to the sense of rotation of the liquid crystal layer 15 , the angle of rotation (φ) of the optical retarder being the same as that of the liquid crystal layer.
[0054] The slow optical axis of the optical retarder, on the side facing the liquid crystal, is at right angles to the orientation direction {circumflex over (n)} of the liquid crystal 15 , and
[0055] The optical path difference of the optical retarder is equal to the optical path difference of the liquid crystal layer 15 .
[0056] Alternatively, a helically twisted retarder can be constructed if a multi-layer system of alternate successive orientation layers and LCP layers, optionally with interposition of de-coupling layers, is so constructed that the planar optical axes of the layers vary in azimuth, resulting in a helical structure.
[0057] Layers with high twist, serving as cholesteric optical filters, are obtained by increasing the concentration of chiral dopants in twisted retarder layers. Owing to the thermal stability of the layers, these filters can be used at temperatures far above 100° C. The wavelength of selective reflection of these cholesteric filters can be varied by varying the chiral dopants. The bandwidth of selective reflection of the filter combination can be varied by superposing at least two cholesteric layers, each with different selective reflection.
[0058] Retarder or orientation layers with an integrated linear polarizer, or absorptive optical filters, can be obtained by adding dichroic dyes, which are oriented by the liquid crystal molecules in the LCP layer.
[0059] Other details are given in the following Examples.
EXAMPLE 1
[0060] Production of a PPN layer.
[0061] The PPN material can comprise, for example, cinnamic acid-derivatives. In the Examples, the chosen material was a PPN with a high glass point (Tg=133° C.).
[0062] A glass plate was spin-coated with a 5% solution of the PPN material in NMP at 2000 rpm for 1 minute. The layer was then dried at 130° C. for 2 hours on a heating bench and for a further 4 hours at 130° C. in vacuo. The layer was then illuminated with the linear polarized light from a 200 W Hg very high pressure lamp at room temperature for 5 minutes. The layer could then be used as an orientating layer for liquid crystals. However, the thermal stability of the orientation capacity is too low for many applications. For example the orientation capacity disappeared e.g. after 15 minutes at 120° C.
EXAMPLE 2
[0063] Mixture of cross-linkable LC monomers for the LCP layers
[0064] The following diacrylate components were used as cross-linkable LC monomers in the Examples:
[0065] These components were used to develop a super-coolable nematic mixture MLCP having a particularly low melting point (Tm≈35° C.), such that the LCP layer could be prepared at room temperature.
[0066] The diacrylate monomers were present in the mixture in the following proportions:
Mon 1 80% Mon 2 15% Mon 3 5%
[0067] 2% of Ciba-Geigy IRGACURE 369 photoinitiator was added to the mixture.
[0068] The M LCP mixture was then dissolved in anisole. The thickness of the LCP layer can be adjusted over a wide range by varying the concentration of M LCP in anisole.
[0069] For photo-induced cross-linking of the LC monomers, the layers, after orientation, were irradiated with isotropic light from a 150 W xenon lamp for about 30 minutes, thus fixing the orientation.
EXAMPLE 3
[0070] Combination of retarder and orientation layer
[0071] A PPN-coated glass plate was irradiated with polarized UV light for 5 minutes. A 40% solution of M LCP in anisole was deposited by centrifuging on to the illuminated layer. Spin parameter: 2 minutes at 2000 rpm. The resulting cross-linkable LCP layer was orientated in accordance with the direction of polarization of the UV light. After cross-linking the LCP layer had a thickness of 2.2 μm.
[0072] If the coated glass plate is disposed under crossed polarizers so that the polarizers are parallel or at right angles to the direction of polarization during illumination of the PPN layer, the plate is dark. If, however, the plate is rotated through 45° in the plate plane, the plate becomes light, i.e. it has double refraction. The optical delay is about 300 nm.
[0073] An isotropic SiO x de-coupling layer 50 nm thick was deposited by sputtering on to the hybrid layer with an optical delay of 300 nm. A PPN layer was then constructed on the de-coupling layer as described in Example 1. The PPN layer was divided into two regions illuminated in different directions of polarization, the direction of polarization of the light in one half being parallel to and in the other half at right angles to the optical axis of the underlying retarder layer. One half was covered during illumination of the other half. The result was two regions with directions of planar orientation at right angles to one another.
[0074] A 5% solution of MLCP in anisole was prepared. The solution was deposited by centrifuging on to the locally variously illuminated PPN layer. Spin parameter: 2 minutes at 2000 rpm. In order to optimize the orientation of the LC monomers, the coated substrate was then heated to just above the clearing point (T c =67° C.). The layer was then cooled at 0.1° C./min to a few degrees below the clearing point and then photochemically cross-linked.
[0075] If this hybrid substrate and a second ground PVA-coated substrate are used to construct an LC cell and the cell is filled with a liquid crystal, the result is a twisted cell (TN) configuration in one half of the cell and a homogeneous planar arrangement of the LC molecules in the other half. The hybrid substrate serves on the one hand as an optical retarder and on the other hand as an orientation layer for the liquid crystal. The optical axis of the retarder can be different from the direction in which the LC molecules are oriented.
[0076] The multilayer layer is thermally and optically stable, as a result of the two cross-linked LCP layers. In place of the SiO x layer, isotropic decoupling layers of nylon were made. To this end, 0.1% nylon was dissolved in trifluoroethanol and deposited by spin-coating on to the first LCP layer.
EXAMPLE 4
[0077] STN cell compensated in situ and with uniaxial retarder
[0078] A PPN layer was applied to an ITO-coated glass plate and irradiated with linear-polarized light. Next, a 53% solution of M LCP in anisole was deposited by centrifugation and cross-linked (spin parameter: 2 minutes at 2000 rpm). The optical delay of this retarder layer was 530 nm. As in Example 3, a second PPN layer was applied, de-coupled from the retarder by an isotropic SiO2 layer. The direction of the polarizer for illuminating the second PPN layer was rotated through 75° relatively to the direction of polarization of illumination of PPN1. A thin LCP layer was deposited on the PPN2 layer after illumination, as in Example 3.
[0079] This substrate and a second, rubbed PVA-ITO glass substrate were used to construct an LC cell with a plate separation of d=5 μm. The second plate was disposed so that the angle between its direction of rubbing and the direction of orientation of the hybrid layer was 240°. The transmission directions of the two polarizers required were adjusted as in FIG. 7. A liquid crystal mixture was first doped with a chiral dopant so as to obtain a d/p ratio of 0.51 (p=pitch). This mixture was poured into the LC cell.
[0080] As long as no voltage is applied to the cell, it appears dark. If, however, a sufficient voltage is applied, the cell changes from black to white. The normal interference colors in STN cells are thus compensated by the retarder layer, avoiding the need for an externally applied compensation foil.
EXAMPLE 5
[0081] Hybrid layer as twisted retarder
[0082] The M LCP mixture was doped with 0.16% of a levorotatory chiral dopant with a high twisting power [helical twisting power (HTP)=0.26 μm −1 ]. The doped mixture was then dissolved to a 40% in anisole and centrifugally applied to an illuminated PPN layer (2 minutes at 2000 rpm). After cross-linking, the thickness of the LCP layer was about 2.2 μm. When the coated plate is observed under crossed polarizers, the direction of transmission on the substrate side being parallel to the direction of polarization of the light illuminating the PPN, the layer does not appear dark as would be the case with a linear retarder. However, the layer is darkest when the analyzer is rotated through 30°. Accordingly, the plane of polarization of the linear polarized light is rotated through 30° in transit through the retarder, corresponding to the twist in the LCP layer.
[0083] The twist can be adjusted between 0° and 360° by varying the concentration of the chiral dopant. A dextrorotatory chiral dopant can be used instead of a levorotatory dopant. These twisted retarders are also of interest e.g. for color compensation of STN displays.
EXAMPLE 6
[0084] STN cell compensated in situ and with twisted retarder
[0085] Instead of a linear retarder, the first PPN-LCP layer combination can be a twisted retarder, thus further increasing the contrast. Consequently, the M LCP mixture for the first LCP layer was doped with a dextrorotatory chiral dopant. The spin parameters were so chosen that the optical delay of the LCP layer was equal to that of the liquid crystal 15 in FIG. 6. The pitch of the LCP layer could then be adjusted via the concentration of dopant such that the angle of rotation of the retarder was equal to the angle of rotation of the liquid crystal. The orientation layer above the twisted retarder was illuminated such that its direction of orientation was at right angles to the slow axis of the retarder on the side facing the orientating layer. In a similar manner to Example 4, this substrate was used to construct an STN cell and filled with a levorotatory liquid crystal.
EXAMPLE 7
[0086] Hybrid layers with locally different colors
[0087] A 50% solution of MLCP in anisole was applied by centrifugation at room temperature on to a PPN layer irradiated with linear polarized light, and was cross-linked. The resulting optical retarder had a delay of 470 nm. Under cross-polarizers, the plate was orange-colored. As in Example 3, a 50 nm thick isotropic decoupling layer of SiO x was deposited by sputtering, followed by a second PPN layer. Layer PPN2 was then divided into three regions, which were illuminated with different directions of polarization. The directions of polarization were parallel in region 1 , perpendicular in region 2 and 45° to the direction of polarization of the illumination of PPN1 in region 3 . During illumination of each region the other regions were covered.
[0088] A 30% solution of MLCP in anisole was applied by centrifuging on to the thus-illuminated PPN2 layer and cross-linked. The resulting LCP layer had an optical delay of Δnd=140 nm.
[0089] If the hybrid layer was disposed under cross-polarizers in such a manner that the direction of polarization of PPN1 illumination lay at 45° to the polarizers, three colors were recognized:
Region Δnd [nm] Color 1 610 Blue 2 330 Yellow 3 470 Orange
[0090] The optical delays of the two LCP layers are added in region 1 region 2 .
[0091] Other colors can be produced by applying further PPN-LCP combinations in an analogous manner to each of these three colors. The illumination of the individual layers can also be effected by varying the polarization directions with angles between 0° and 90° compared with the first illumination. Thereby, Lyot/Oehman or olc interference filters can also be realized, the transmission range of which being adjustable by the number of layers, their thickness and the direction of their optical axes. The transmission range can be variously adjusted pixel-wise by the structuring.
EXAMPLE 8
[0092] LCP layer for optical filters/polarizers circular polarizers)
[0093] The M LCP mixture was doped with 12% of the chiral levo-rotatory dopant in Example 5. The resulting cholesteric mixture had a pitch of about 360 nm. The doped mixture was dissolved to 40% in anisole, applied centrifugally to a PPN layer illuminated with linear polarized light and cross-linked. The resulting layer acted as a cholesteric filter with a selective reflected wavelength of λo=580 nm. The width of the reflection bands was 70 nm.
EXAMPLE 9
[0094] Dichroic LCP layers as linear polarizers
[0095] 2% of a dichroic dye with the following structure:
[0096] were added to the M LCP mixture. This mixture was dissolved to 30% in anisole, centrifugally applied to a PPN layer illuminated with linear polarized light and cross-linked. If a polarizer was held with its transmission direction parallel or perpendicular to the direction of polarization of the PPN illumination, the white light was transmitted in one case, but at right angles thereto the layer was colored depending on the absorption spectrum of the dye. The dichroic ratio was 8:1. If in place of this a black mixture of dichroic dye molecules is used, the hybrid layer serves as a wide-band polarizer. As a result of the local irradiation of the PPN layer with different directions of, linear polarizing layers can be produced with azimuthally varying directions of polarization. These can be used in LC displays, e.g. in conjunction with the structured retarders and orientating layers in the Examples hereinbefore.
[0097] Upon reading the present specification, various alternative embodiments will become obvious to those skilled in the art. These embodiments are to be considered within the scope and spirit of the invention which is only to be limited by the claims which follow and their equivalents.
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An optical component having a hybrid layer structure includes an orienting layer, a further layer in contact with the orienting layer and incorporating a cross-linked liquid crystalline monomer and at least one additional orienting layer on top of the liquid crystalline layer, and preferably includes one additional cross-linked liquid crystalline monomer. The layers have different functions, such as orienting or retarding. At least one of the orienting layers should be a photo-orientating polymer network layer, or have locally varying orienting pattern. These optical components are useful in transmittance and reflective liquid crystal displays, such as rotation cells, STN cells, ferroelectric cells, and cells having an addressable active matrix. Such cells are useful in optical and integrated optical devices, and may be used for safeguarding against counterfeiting and copying in transmission.
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This application claims benefit of U.S. Provisional Application Ser. No. 60/038,837 filed on Feb. 18, 1997.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a support frame for a ladder and, in particular, to a frame having a two-dimensional horizontal component and a vertical component for supporting a standard extension ladder or the like.
2. Description of the Prior Art
Many accidents are caused on construction sites or in domestic environments with the use of conventional extension ladders or straight ladders. The foot of the ladder, particularly when used out of doors, often has one side rail which is unstable because of the unevenness of the terrain. Since the top end of the ladder, which usually leans against a wall, is not supported other than on the surface of the wall, it is subject to sliding sideways, particularly when the weight of a person is near the top of the ladder.
SUMMARY OF THE INVENTION
It is an aim of the present invention to provide a portable support structure for fully supporting an extension ladder or straight ladder.
A construction in accordance with the present invention comprises a support frame having a longitudinal axis and a lateral axis, a ladder-receiving bracket pivotally mounted on the support frame for pivoting movement about a lateral axis relations to the support frame. At least one support strut is pivotally mounted about a lateral axis, to the support frame, and is spaced on the support frame from the pivot axis of the ladder-receiving bracket, the strut having a free end to be connected to the pivoting bracket for forming a structural triangle between the support frame, the ladder-receiving bracket and the strut, wherein the ladder, with the foot inserted in the ladder-receiving bracket, will be supported with improved stability.
BRIEF DESCRIPTION OF THE DRAWINGS
Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration, a preferred embodiment thereof, and in which:
FIG. 1 is a perspective view of an embodiment of the present invention;
FIG. 2 is an enlarged fragmentary view of the support structure in accordance with the embodiment shown in FIG. 1;
FIG. 3 is a side elevation, partly in cross-section, of the support structure in accordance with the embodiment shown in FIGS. 1 and 2,
FIG. 4 is an enlarged perspective fragmentary view of another detail of the support structure shown in FIG. 1;
FIG. 5 is a fragmentary perspective view of another embodiment of the present invention;
FIG. 6 is a side elevation, partly in cross-section, of the support structure in accordance with the embodiment shown in FIG. 5;
FIG. 7 is a fragmentary end elevation taken along line 7--7 in FIG. 6, showing a detail of the support structure in accordance with the embodiment of FIGS. 5 and 6; and
FIG. 8 is a fragmentary enlarged longitudinal cross-section of a further embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, an extension ladder 9 is shown having side rails 9a and 9b as well as rungs 9c. The extension ladder is shown mounted on a support frame 10 in accordance with an embodiment of the present invention. The support frame 10 includes a pair of longitudinal, parallel, spaced frame members 12a and 12b to which are welded lateral square tubular members 14a through 14e. The longitudinal members 12a and 12b and lateral members 14a through 14e form the core of the platform 12.
Lateral extensions 16a through 16e and 18a through 18e telescope within respective box frame members 14a through 14e. For instance, lateral telescopic extension 16a slides within the lateral square tubular member 14a at one end thereof while extension 18a telescopes at the other end of the frame member 14a. Each extension member 16a and 18a is provided with a plurality of spaced apart holes 19 which can be engaged by pins or bolt and nut devices 20 which pass through the square tubing of frame member 14a to thereby lock the extension 16a or 18a at the desired extended or retracted position.
Typically the width of the platform 12 is 22" while the extensions 16 and 18 are preferably set so that the total width of the frame is 26". The platform 12 can be extended laterally by means of extensions 16 and 18 to a maximum of 40".
A shoe 21 is fixed to the end of each extension 16 or 18. The embodiment, which is shown in FIGS. 1 and 2, is suitable for an even horizontal deck, such as interior flooring or a paved outdoor surface.
The frame members 12a and 12b can be extended longitudinally by means of sliding members 13a and 13b to which is mounted a lateral member 14e. Extensions 13a and 13b extend from the longitudinal square tubular frame members 12a and 12b and can be locked in the same manner as extension members 15 and 18.
The ladder-receiving clamping bracket 22 includes side members 24 and 26 and front and rear plates 28a, 28b, 30a, and 30b. These components form a rectangular box-like enclosure for receiving the side rails 9a and 9b of a typical ladder. Clamp plates 32a and 32b are mounted on guide pins 34 which pass through the rear plates 30a and 30b. Threaded stems 36 with handles are operative to move the clamp plates 32a and 32b relative to the rear plates 30a and 30b in order to securely clamp the side rails 9a and 9b within the clamping bracket 22.
As shown in FIG. 2, the clamping bracket 22 is pivoted about a lateral axis in pivot brackets 38a and 38b. There are two pairs of struts. The pair of struts 40 includes telescopic struts 40a and 40b pivoted by means of pivot brackets 42 to respective longitudinal frame members 12a and 12b. The other ends of struts 40a and 40b are pivoted to the clamping bracket 22 at pivot brackets 44a and 44k. The struts 40a and 40b can be extended telescopically and locked in a fixed position in the same manner as extension members 16 and 18.
A second pair of struts 50 includes struts 50a and 50b. Struts 50a and 50b are pivotally mounted to brackets 52a and 52b on the lateral frame member 14e. Struts 50a and 50b are telescopic and can be adjusted in the same manner as extensions 16 and 18. As shown in FIG. 4, a pair of plates 54a and 56a are adapted to be mounted on respective side rails 9a and 9b. The plates may have openings conforming to a typical rung cross-section, and rods 56 and 58 extend through the hollow rungs 9c through the openings in the plates 54a and 56a. Lock pins 59 hold the plates 54 and 56 on respective rods 56 and 58. A telescopic leg 60 extends between the plates 54 and 56 may be locked in place by a set screw 62. Pivot brackets 64a and 64b are provided at the end of struts 50a and 50b and are pivotally connected to tabs 66a and 66b mounted respectively on side plates 54a and 54b.
Thus, when using this support structure for supporting a typical extension ladder 9 or a straight ladder, the foot of the ladder is inserted in the clamping bracket 22, and the clamp plates 32a and 32b are adjusted against the side rails 9a and 9b of the ladder, as shown in FIGS. 2 and 3. In FIG. 3, shoes 9d are shown being engaged by the clamp plate 32b. The typical width of a ladder is 17", and it would normally fit comfortably in the clamping bracket 22 which has an overall width of 22". The ladder may be leaning against the wall at a preferred angle of 75°, and the pairs of struts 40 and 50 are then adjusted to the angle of the ladder. Plates 54a and 54b are mounted to side rails 9a and 9b at a suitable height of the ladder, and struts 50a and 50b extend so that brackets 54a and 54b can be pivotally connected to the tabs 66a and 66b respectively.
In a preferred embodiment, a plate or expanded metal screen 15 is mounted on platform 12 of the support frame 10 for stepping onto the first rung of the ladder.
Referring now to the embodiments shown in FIGS. 5 through 7, reference numerals are raised by 100 to identify elements which correspond to elements identical in the embodiment shown in FIGS. 1 through 4.
The support frame 110, as shown in FIGS. 5 and 6, includes a frame member or platform 112 with longitudinal frame members 112a and 112b to which are welded the lateral frame members 114a to 114e. However, the ends of the extension members 116 and 118 are provided with legs 170 which can be adjusted vertically. At the end of extension 116b, a socket 172 is provided to receive the square tubing of leg 170. Bolts and nuts can be passed through the socket 172 to engage spaced-apart opening in the foot 170. Thus, on uneven terrain, the platform 112 can be adjusted so that it is horizontal and level.
As shown in FIG. 5, the lateral member 114a may extend between the leg 170a in order to provide additional lateral stability. As far as the support frame 110 and the pivoting bracket 122 are concerned, the structure is essentially the same as in relation to FIGS. 1 to 4.
FIG. 7 shows that the shoes 121 can be pivotally mounted to the ends of feet 170 to enhance the contact with an uneven terrain.
FIG. 8 shows essentially the support frame of the embodiment shown in FIGS. 1 to 4 and corresponding reference numerals have been raised by 200. In the embodiment of FIG. 8, the lateral frame members 214b and 214d have been raised on short extensions welded to the longitudinal frame members 212a and 212b. Threaded sleeves 282 are welded to the lateral frame members 214b and 214d, and a threaded stem 286 can move vertically in the sleeve 282. A handle 254 is provided at the top end of the stem 286 in order to move the stem vertically. The other end of the stem 286 is provided with a reinforced swivel plate 290 to which swivel caster wheels 288 have been mounted.
Thus, in the event that the support frame of FIGS. 1 to 4 needs to be moved from one location to another on an even floor or outside pavement, the wheels 288, and there would be two wheels near each end of the support frame, are lowered to engage the flooring and to raise the support frame of the floor so that it can be pushed around.
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A support kit supports a free-standing ladder. The kit includes a support frame with adjustable legs to keep the support frame level and a ladder-receiving bracket pivotally mounted on the frame about an axis extending laterally of the frame. A set of struts is pivoted to the frame spaced from the ladder-receiving bracket and extend to connect to the ladder-receiving bracket to form a structural triangle. Another set of struts is pivoted about a lateral axis spaced from the first set of struts and extends to a strut-receiving bracket mounted to the ladder above the ladder-receiving bracket to form a second structural triangle.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part application to my co-pending application Ser. No. 893,850, filed on Apr. 6, 1978 now abandoned.
BACKGROUND OF THE INVENTION
Up to the present time no process such as that of the present application has been known for producing articles similar to the natural materials above mentioned; what is known in the art is the production of pieces of cast metal or ceramics, obtained by means of molds. The effort has been made to produce rigid plastic articles, similar to such natural materials. However, success has not been achieved in imitating bamboo, and the the invention is accordingly limited to the reproduction of simulated bamboo.
Up to the present time pieces of furniture such as chairs, rockers, headrests, shelves, tables and the like have been produced from rattan, bamboo and other natural materials, which have an extremely high cost and which require a great deal of maintenance; furthermore they cannot be used out of doors because of their low resistance to the elements, and are also easily broken, since these natural materials are not sufficiently strong to bear fairly great weight.
In the specific case of rattan, it is well known that this material is scarce, since it grows only in Eastern countries, and very expensive; it is also difficult to work and requires selection; finally the pieces made from it cannot be used out of doors.
Furniture made from natural materials, such as a chair or a rocker, generally include cushions which are covered with cloth, other textile material, plastic, or leather; these cushions are supported by a reed or wickerwork woven structure built into the piece of furniture, presenting the same drawbacks as pointed out above. An additional problem arises from the method required for weaving wickerwork, since it must be kept submerged in water to give it flexibility and ease of manipulation. This method, besides being slow, is dirty, and there is always the risk of wetting delicate portions of the furniture.
The procedures for coloring or veining various articles of different materials such as ceramics and metal, and making them resemble the veining of wood, have consisted merely of coloring or dying the surface of the materials, later applying a coat of varnish or lacquer to provide a brilliant surface, or merely of applying on the surface thin layers of printed wallpaper that simulated the veining of wood.
These processes have the disadvantage that they are not very appropriate for application to thermoplastic materials, since paints or dyes generally do not show good adherence to these synthetic materials; and consequently the application of any solvent, however weak, or mere use and exposure produce deterioration and removal of the paint, leaving the synthetic material exposed and unprotected.
The procedures known heretofore for typing knots for this type of furniture, using straps or strips of rattan bark, reeds, rushes or rawhide have the drawback that they must be secured by means of nails or other device. These ties also have poor resistance to weathering, and also the tendency to stretch or shrink with changes of temperature; they also eventually get dirty, rot, and fail.
These systems of typing are very well known, as is the use of natural materials for carrying them out, as proposed for example in U.S. Pat. Nos. 2,936,009 and 3,297,063 of John C. McGuire, in which rawhide is used to make the ties, which are secured in place with nails, tacks, etc.
SUMMARY OF THE INVENTION
In view of what is set forth above, it is the object of the present invention to produce articles which are identical to the eye and to the touch with those made of natural materials, such as rattan, bamboo, cane, reed, wicker and the like, but which are made of rigid thermoplastic materials having an appearance like that of the natural materials but being more durable and of comparatively lower cost than the said natural materials, and furthermore being easy to work in all sizes and diameters, and being susceptible of mass production in every type and color desired of the natural material it is intended to imitate.
Another object of the present invention is to form protruberances which simulate the knotty and non-symmetrical portions, with ridges and marking, similar to the irregularities of the natural material. Once this phase has been completed, the tubular lengths are thermally molded, giving suitable shape to the sections which will make up the furniture and structures.
By means of the procedure for coloring and veining the synthetic thermoplastic materials of the present invention, all of the problems above mentioned are avoided, since the paint or pigment with which the surface of the synthetic thermoplastic materials is to be colored or grained is dissolved in a solvent effective upon the thermoplastic material. If desired, when the pigment is dissolved in the solvent, a small amount of the thermoplastic material itself which is to be veined can be dissolved, thus achieving a better adherence upon applying the coloring or veining applied to the surface of the synthetic thermoplastic material, causing the coloring or pigment to be absorbed into and form part of the material itself when the solvent evaporates. In this way the said pigment is intimately infused within the material and it is very difficult for the veining to be removed either by wearing aways of the material, by the application of some light solvent applied to the surface, or by weathering.
The advantage is also obtained that these synthetic articles are light but strong and easy to work, and present an appearance which is identical in looks and feel to the natural materials, and can be used indoors and outdoors with no maintenance. In imitations of wood graining, very rare and costly woods can be simulated avoiding the use of the natural materials, limiting importation and excessive exploitation of forests.
Another advantage of the present invention is that of providing a way of joining the furniture, structures and ornaments in general, whether of natural or synthetic materials, by means of typing them with narrow strips or ribbons of Polyvinyl chloride. Before the tubular portions are tied, however, they have to be attached to each other by simple soldering, by attaching a plug or stopper and screw at the end of the other portion; or by other connecting means such as an injected plastic connector also attached to the ends of the tubes. Afterwards, a better and permanent fastening is obtained, for the reason that after the tie of PVC is heated by means of applying heat or microwave treatment, or without heat through the action of time at ambient temperature, it contracts permanently and provides a very firm and tight tie in an elastic manner. Such a tie will neither slacken nor release, notwithstanding later application of heat or cold, and will not permit the joints to open. This characteristic is heightened by forming striations or grooves in one or both surfaces at the moment of extrusion to give the material greater adherence, and making it unnecessary to use any other means of locking engagement such as nails, staples, bonding, adhesives and the like; it is necessary only to link the ends of the tie together suitably.
The strips or ribbons of PVC can be molecularly oriented in the lengthwise direction, as is well-known in the field of heat-shrinking plastics under the term "memory", at the time of their extrusion, so that when heat, light or microwave treatment is applied, or through the mere effect of the ambient temperature they will undergo permanent shrinking thus tightening the tie made with this material.
The ties or ribbons of PVC can be colored like the tubular sections to give them an appearance similar to that of natural materials such as reed, wicker, rattan bark, cane, bamboo and the like, cut lengthwise, as well as of rawhide strips, etc.
The ties made of PVC also provide the important advantage that they do not rot nor permit absorption of moisture nor dust. They can be used out of doors, giving a natural and esthetically pleasing appearance and better resistance to weathering, and stay tight even when the material tied expands or contracts; thus they give much firmer joints than natural materials known up to the present time.
The tie of PVC of the present invention can be used on natural materials with the same advantages described above or firmness combined with a natural appearance.
In the case of furniture made with natural or with synthetic materials which have cushions on the seat portion, the use of contractable PVC strip or ribbon of uniform base color, with a cross-sectional shape which can be round, oval, flat or rectangular, in suitable lengths and widths as desired, upon which very fine lengthwise striations have been formed, and which has been given a grained appearance according to the method described above, affords the advantages already cited above and others as well.
The interlacing which serves as base for the seats, or for structural or merely ornamental purposes, can be made of PVC strip, with important advantages over natural materials. In some pieces of furniture the tubular profile, knotted and veined, can be the peripheral structure, and the interweaving performed with PVC strip will give the precise appearance of furniture made of wickerwork.
This interweaving has been tried with other materials and other techniques, but it has not been possible in these cases to get away from the artificial appearance.
Another additional advantage is that this material can be worked on when cold and dry, without the need for special treatments and without dirtying the piece of furniture, along with the advantages of tensioning and resistance to weathering already mentioned.
In the case of furnitures made to imitate bamboo, the strips of split bamboo are replaced with similar strips of PVC extrusions and a plank can be formed and incorporated into the piece of furniture, texturizing it with striations and veining it in the manner already described.
The materials that are imitated according to the instant invention belong most of them to the grass family and are known for their following characteristics:
(1) Bamboo (technical name Bambusaceae).--tall plant with hard, hollow, jointed stems, of the grass family; stem, used as a stick or support.
(2) Rattan (technical name Calamus Rotang).--East Indian palmtree with a cane-like stem. The commercially called reed used in the manufacture of chairs, baskets, etc, is the split inner portion of rattan in cylindrical form, like true reeds.
Rattan is usually known as reed, when used for woven furniture. (Encyclopedia Americana).
The rattan vine is harvested by natives, then cured and classified as to size and texture, the bark is removed and treated, thus becoming "cane" and used most extensively as seats for chairs.
The wood part of the rattan vine inside the bark is treated and the finished product is known as reed; while being woven, reed is kept in water so as to make it pliable.
The lack of willow and the dissatisfaction over reed owing to its brittlness has caused furniture and basket makers to seek a new article. (Encyclopedia Americana)
Rattan.--stems (collectively) as used for building, basketwork, furniture, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
The characteristics features of the present invention are also shown in the following description and in the drawings which accompany it.
FIG. 1 is a view in lengthwise elevation showing the stage of applying heat and pressure to produce the knotty sections in a tubular portion.
FIG. 2 is a view in lengthwise elevation showing a tubular portion with the typical joint shape produced.
FIG. 3 is a view of a finished length which has been colored, engraved and slotted, with markings on the node.
FIG. 4 is a view of finished portion which has been colored, engraved and slotted, showing divisions and markings of an article resembling bamboo, rattan, cane, or the like.
FIG. 5 is a view in elevation of two tubular lengths of thermoplastic synthetic material joined in a T. showing one way of tying or joining the lengths.
FIG. 6 is a view showing two tubular portions of synthetic thermoplastic material, indicating another manner of typing the tubular portions together.
FIG. 7 is a view in conventional perspective of a finished piece of furniture showing the lengths of PVC which have been colored, veined, bent, brought together and tied with PVC strip.
FIG. 8 illustrates an extrusion die and a traveling mold installation.
FIG. 9 illustrates the traveling molds in their traveling operation.
FIG. 10 illustrates one end view of one traveling mold in its closed position.
FIG. 11 illustrates a traveling mold and end view in its open position.
FIG. 12 illustrates a traveling mold in its open position such as that of FIG. 11 in a conventional perspective view.
FIG. 13 illustrates a traveling mold of FIG. 9 in their traveling operation showing the molds in their close, open and semi-closing positions.
FIGS. 14 to 17 illustrates various manners by which the extruded tubes are connected before they are tied to form the structures of the invention.
FIG. 18 illustrates a slotting mold by which the surface of the extruded tube is slotted.
FIG. 18 A is a detailed view of section A of FIG. 18 illustrating how the slots are formed on the tube surface.
FIG. 19 illustrates a manual version to slot the surface of the tubes by a file used manually.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, the procedure for producing synthetic articles identical in appearance and to the touch with rattan, bamboo, cane, reed, wicker, rush and similar natural materials according to the present invention consists of forming a tubular length 20 out of a rigid or semi-rigid thermoplastic material in any suitable color by a suitable tube making process, preferably by extrusion, which has the advantage of being seamless. The said tubular section 20 is chilled and becomes rigid; heat is then applied to selected portions of length 20 and pressure is applied from the sides as shown by arrows for the purpose of deforming the heating profile 22 outward, simulating nodal formation 25, as is shown in FIG. 2. When the wall of the tubular portion is very thin, it is desirable to introduce a shaper (not shown) inside the tube, to prevent it from warping or sucking in as the nodal portion 25 is formed. Tubular section is then cooled again, along with nodal portion 25, and the tubular portions are then colored and veined again as required; portion of tubular material 20 is again heated at the desired points to give it the shape and the bends required.
For producing articles similar to cane, reed, bamboo or wicker, grooves 24 are made, as well as spiral striations 26 and circular shallow incisions 27, in the selected portions, immediately after heating and before forming node 25, to simulate the separation of the joints in the natural material and also portion 28 which is caused when the leaf is torn from the trunk of the natural cane, reed or similar stem in natural materials, etc., by applying pressure to form the node and expanding the striations and incisions slightly.
The formation of the tubular length can be made by any known process, but as indicated above extrusion is preferred because it does not leave visible seams.
In one embodiment invention a thermoplastic tube 20 as illustrated in FIG. 8 is extruded as per extruder 40' and die 40 through whose central portion two pulley wheels 42 are held which are separated from each other by a smaller distance than the length of the traveling molds 36. Likewise, a tubular duct is connected to the die entering system while leaving air exit 43 between the two pulley wheels. The speed of the traveling molds is adjusted to coincide with the speed of the tube being extruded. The motion of the traveling molds is carried out by conventional motion means 39, and when one of the molds 36 is exactly below tube 20, the mold closes surrounding the tube while pressured air is fed through duct 41 leaving through exit 43, and as tube 20 is hot it will immediately take the shape of the mold because pulley wheels 42 prevent the air pressure to be lost. At the same time cold water is circulated from entrance 38 of the mold and leaving through exit 38' by which tube 20 is cooled, taking the shape imparted to it by the mold whose cavity 37 produces the nodal portion 25. During this operation the tube portion is also calibrated. When the said mold and the tube portion inside it, have traveled a distance equal to the mold length, the latter closes upon the tube that coincides with it, and the whole operation is then repeated for each mold in order to form other nodes and calibrating the tube portion.
Once the tube portions are extruded as above, they are cut in desired lengths, or they may be bent so as to have them ready for assembling the desired structures. However, before they can be tied together to form the pieces of furniture such as illustrated in the enclosed photographs, they have to be connected by using connecting means such as illustrated in FIG. 14 that shows plug 45 and plug 45' as shown in FIG. 16. They can also be connected by welding such as welding element 46 of FIG. 15 or by the screw 47 and the plug 48 combination as shown in FIG. 17. After the portions are connected as indicated above they can be tied as per FIGS. 5 to 7.
According to the invention another embodiment to be considered is that illustrated in FIGS. 18 and 19 in the former of which small slots are produced on the outer surfaces of the tubes by the slotting die 49 whose slotting section 50 produces the slots that resemble the surface of natural materials as bamboo and rattan. However, such operation can be peformed manually when smooth surface die is used, by using a file 51 such as that illustrated in FIG. 19.
Similarly, the node can be formed by inserting a suitable tool inside the tube to provide an outward deformation of the heated portion, or air or gas under pressure can be applied inside the tube to cause the heated portions to swell and simulate joints. In the tubular length the nodes can be distributed either with regularity or irregularly as desired, by means of the methods indicated.
A mold to provide the desired external appearance of the node or joint or intermediate surface can be placed around the outside of the heated portion of the PVC tube, and when the latter is expanded by gas or by a tool operating inside the PVC tube, the exterior surface will take on the surface texture of the mold surface.
The external mold may also have pores or slots communicating with a vaccumm source to draw and squeeze the softened tube material thereinto for further simulation of ridges and protruberances of the natural material imitated.
Below examples are given of preferred processes for coloring and graining synthetic thermoplastic materials to cause them to resemble wood, rattan, and similar natural materials.
EXAMPLE 1
Tubular portions 20 are prepared by extruding PVC thermoplastic material which already has a uniform base color similar to that of wood, as shown in FIGS. 3 to 7; a layer of suitable solvent which may be either tetrahydrofuran or methylene chloride is then applied over selected portions 29, 30 of the said surface for the purpose of dissolving a very thin layer of the surface of the portion and the veining is then applied using a suitable pigment dissolved in the solvent itself which may be a mixture of (Hoechst Chemical Co.):
(A)
1. Yellow Sol HR
2. Permanent Red TG-01
3. T 1 O 2
4. Carbon Black
5. Ca CO 3 , employing a suitable applicator such as cloth bag or brush, forming graining 29 or knobs 30 like knotty portions; finally, if desired, a light layer of varnish or a matte tone can be applied, or a mere coat of wax or matte lacquer.
EXAMPLE 1 A
The same procedure as in Example 1 is repeated except that Acrylonitrile-butadiene-styrene copolymer is extruded and acetone is used as the solvent.
EXAMPLE 1 B
The same procedure as in Example 1 is repeated but polystyrene is the material extruded and thinner is used as the solvent. The pigment used is Hoecht's Orango L-404 mixed with Brown L-701.
EXAMPLE 2
Tubular lengths 20 of thermoplastic material are prepared, with a uniform and integral base color similar to that of rattan; a solvent is applied over selected portions 29, 31 of the said surface to dissolve a light layer of material, and to this surface a suitable pigment is applied dissolved in the solvent itself, generally using pincers to produce the effect of knotty portions (not shown) and veins 29; the material is allowed to repose so the solvent will evaporate and thus allow the veining to form part of the stock itself, on its surface; finally if desired a light layer of varnish or lacquer may be applied.
EXAMPLE 3
Tubular length 20 are prepared with nodes, from a synthetic thermoplastic material having an integral base color similar to that of bamboo; a light layer of solvent is applied over selected portions (not illustrated) of the peripheral surface of the length for the purpose of dissolving a thin superficial layer of the surface, and manually spots and striations are applied around nodes 25, to give them the appearance of bamboo of the kind shown as Indian cane or Bengal reed.
Referring now to FIGS. 5 and 6, detailed illustration is made therein of ties consisting of a strip of PVC 32 over a structure of natural material 20 in one embodiment of the present invention.
The strap of PVC 32 is of one piece and is secured by means of interlacing 38 suitably at its ends which are tucked under; thus there is no need for using nails or tacks to secure it. PVC strap 32 exhibits striations 34 and graining 35.
The strap of PVC 32 with the stated characteristics gives the precise appearance and tactile sensation of a piece of furniture made entirely from natural materials and has also the firmness and strength of polyvinyl chloride.
Longitudinal striations 34 are formed on the strap of PVC used in this embodiment of the invention at the moment of its extrusion or subsequently, with a suitable tool. Veining 35 is accomplished in a manner similar to that for the tubular sections described above, again affording appearance and touch like that of furniture made from natural materials.
While the foregoing description is drawn to specific concrete embodiments of the invention, it will be understood by persons versed in the subject matter that changes in form and detail are within the scope and spirit of the present invention.
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This invention relates to the production of tubular articles, made from synthetic thermoplastic materials, which resemble wood, rattan, bamboo, cane, reed, wicker, reed, rush, and similar natural materials, and also to the production of furniture, structures, and every kind of ornament in general employing thermoplastic materials which replace the natural materials mentioned above, coloring and veining such thermoplastic materials, and also joining and securing by means of ties made from rigid, semi-rigid or plastified polyvinyl the natural and artificial materials above mentioned, for the purpose of assembling furniture and structures in general.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a division of U.S. application Ser. No. 08/507,419, filed Oct. 6, 1995 and granted Aug. 29, 2000 as U.S. Pat. No. 6,110,378 is also a 371 of PCT/US94/01718 and a continuation-in-part of application Ser. No. 08/023,606 now abandoned.
Other related applications are Ser. No. 07/998,997, entitled Thin Film Hydrous Metal Oxide Catalysts, Dosch, et al., filed Dec. 31, 1992, and Ser. No. 07/751,003, entitled Crystalline Titanate Catalyst Supports, Anthony et al, filed Aug. 28, 1991, now U.S. Pat. No. 5,177,045, issued Jan. 5, 1993, the teachings of which are incorporated herein by reference.
GOVERNMENT RIGHTS
The U.S. Government has a paid-up license in this invention under Contract No. DE-AC04-76DP000789 from the United States Department of Energy, and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by certain contract terms.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to novel silico-titanate compositions of matter, and methods of making and using such compositions.
2. Background Art
Synthesis of molecular sieves and zeolite-type materials are known to the prior art. The crystalline structure of such materials permits cation or anion exchange (or both) as well as water molecule exchange. Further, such materials not only separate molecules of different size, but are capable of segregating molecules of the same size but of different electrical charge.
Among other uses for molecular sieves, or zeolite-type materials, are as “carriers” for certain volatile catalysts, facilitating chemical reactions. The catalysts are trapped and thereby retained in the zeolite molecular structure during the chemical process. Channelized zeolite-type materials resembling tectosilicates, however, are not the only structures that can effect ion exchange. Several phyllosilicates of clay-like materials, for example, montmorillonite (smectite) and vermiculite, readily exchange cations between the tetrahedral layers.
Syntheses of silicon titanate zeolite-type materials is known to the art. U.S. Pat. No. 3,329,481 to Young, entitled Crystalline Titano-Silicate Zeolites, discloses several Group IV-B metallo-silicate zeolites wherein the metal may be a monovalent or bivalent metal, as well as ammonium or hydrogen.
U.S. Pat. No. 4,938,939, to Kuznicki entitled, Preparation of Small-Pored Crystalline Titanium Molecular Sieve Zeolites, discloses a process of producing crystalline titanium zeolite-type compositions having a pore size of 3-5 Angstroms.
U.S. Pat. No. 4,853,202, also to Kuznicki, entitled Large-Pored Crystalline Titanium Molecular Sieve Zeolites, discloses methods of making crystalline titanium molecular sieve compositions having a pore size of about 8 Angstroms.
“The OD Structure of Zorite” Sandomirskii et al., Sov. Phys. Crystallvgr., 24(6), November-December 1979, discloses the crystallographic structure of a naturally occurring alkaline titanosilicate found in Siberia.
U.S. Pat. No. 5,015,453 to Chapman entitled Crystalline Group IVA, Metal-Containing Molecular Sieve Compositions, discloses titanium-silicates, phosphates and phosphosilicates which are three-dimensional microporous crystalline structures.
“The Crystal Structure of a New Natural Sodium Titanosilicate,” by E.V. Sokolova et al., Sov. Phys. Dokl., 34(7), 583-585, July 1989, describes a naturally occurring material, sitinakite, found in the former Soviet Union having an empirical chemical formula of (Na 2.251 K 0.693 Ca 0.0004 Sr 0.062 Ba 0.026 Ce 0.004 ) Σ3.04 ×(Ti 3.56 Nb 0.195 Fe 0.014 Zr 0.006 ) Σ4.03 Si 1.928 O 13 (O 0.45 H 0.955 ) Σ1.00 ×3.7 H 2 O which, as an idealized formula, comprises Na 2 (H 2 O) 2 [(Ti 4 O 5 (OH)(SiO 4 ) 2 ]K(H 2 O) 1.7 . Within this material specimens having higher Nb impurity contents are speculated to have an orthorhombic symmetry.
SUMMARY OF THE INVENTION (DISCLOSURE OF THE INVENTION)
The present invention relates to silico-titanate compositions (TAMs), structures of these compositions, methods of making these compositions, and methods of using these compositions. The silico-titanate compositions of the present invention (hereafter referred to as “TAM” compositions) reside within the range of the general formula and have a mole ratio of:
ySi:aTi;
wherein y comprises a coefficient of between 0.01 and 1.7 and preferably less than 1 and a=1.0.
The TAM composition may further comprise a metal dopant (MD) having the general formula zMD to provide the general empirical formula zMD:ySi:aTi, wherein z is a coefficient having a range of approximately 0.0 to 1.0 and y and a have values as defined above. Useful metal dopants include Group III elements, Group V elements, Group IV elements, Group VIII elements, Group I elements, and compounds thereof, particularly niobium, antimony, vanadium, copper, manganese, iron, phosphorus, tantalum and the like.
The composition may further comprise a cation (M), which are at least in part ion-exchangeable, having the general formula xM, in which event the empirical chemical formula is xM:zMD:ySi:aTi, wherein x is a coefficient having a range of approximately 0.0 to 2.0 and, a, y and z have the values set forth above. Useful cations include Group I elements, Group II elements, hydrogen, ammonium cations and alkylammonium cations. The composition may further comprise elements or compounds such as palladium, platinum, rhodium, molybdenum, nickel and sulfur.
The TAM compositions assume different crystalline structures which are dependent upon the atomic elements comprising the TAM composition and, with respect to a given set of atomic elements the atomic ratios existing therebetween. For example, the existence or not of a Group I or II cation (M) constituent distinguishes TAM-3 (no Group I or II cation constituent) from TAM-1, 2, 5, 7 and 8. Wherein a TAM composition contains a cation (M) constituent, the nature of that cation distinguishes TAM-8 (cation is K) from TAM 1, 2, 5 and 7 (cation is Na). Within a line of TAM compositions having an identical cation (M) content, such as Na in the case of TAM-1, 2, 5 and 7, distinctions in the crystalline structures thereof appear in relationship to the atomic ratios of Si:Ti and M(═Na):Si such that at Si:Ti≧1.0 and M:Si:<1.0 the TAM compositions exhibit as a primary x-ray diffraction line one at 2θ<11.00 (TAM-1 and 2) whereas at Si:Ti<1.0 and M:Si>1.0 the TAM compositions exhibit as a primary x-ray diffraction line one at 2θ>9.
The present invention further comprises a method of making silico-titanate compositions and products thereof, the method comprising the steps of:
a) providing a reaction mixture containing a titanium source and a silicon source; and
(b) allowing the resulting mixture to react to form the silico-titanate compositions discussed above.
The titanium source is provided from titanium alkoxides, titanium halogens, titanium oxides, and the like. The silicon source is provided from silicon alkoxides (such as tetraethyl orthosilicate), colloidal silica, silicon oxides, sodium silicates and the like. The reactor charge mole ratio of Si to Ti is between 0.01 to 1.7.
The present invention also relates to the use of the TAM compositions as well as other crystalline titanosilicates, such as sitinakite, as ion-exchange materials; e.g., for sequestering radioactive cations from aqueous media as ion-exchange thin film supports; in a catalytic reaction or as catalytic supports, for fluid chemical and biochemical selectivity, such as in treating radioactive waste streams and detection of trace metals; sensors to sense the presence of target chemicals and biochemicals; and in a wide variety of processes, including ion exchange hydrotreating, dehydrogenating, oxidation, epoxidation, reduction, photochemical processes, electrochemical processes, hydrocracking, cracking, hydrogenating and the like.
The method of using the TAM compositions of the invention is particularly useful for chemical or biochemical reactions or removing radioactive matter and trace metals from a fluid stream. This method comprises the steps of:
a) providing the silico-titanate composition discussed above, to the fluid stream; and
b) permitting the radioactive matter or trace metal in the fluid stream to bind to the silico-titanate composition. Binding is accomplished through ion exchange, adsorption, absorption, size selectivity, and the like. This method is particularly useful for removing radioisotopes from waste streams, including cesium, strontium, plutonium, cobalt, iodine, technetium, rhenium, ruthenium, nickel, cerium, uranium, neptunium, americium, lanthanides, actinides, and the like.
Doped silico-titanate compositions are preferable for some applications, including the removal of radioisotopes and trace metals from fluid streams. The preferred dopants are from Group III elements, Group V elements, Group IV elements, Group VIII elements, Group I elements, and compounds thereof, such as niobium, antimony, vanadium, copper, manganese, iron, phosphorus, tantalum, and the like.
The compositions of the present invention have unique shapes, not present in prior silico-titanate compositions. These shapes include elongated strands, parallelepipeds having approximately 90 degree angles, cuboids, ellipsoids, spheres, a collection of elongated strands in spheres, and internal ribbed structures bound substantially by silicon compounds.
The new silico-titanate compositions provide for more efficiently segregating radioactive elements or trace metals from waste streams; are serviceable as catalyst supports or in catalytic reactions; and provide new molecular sieve compositions which are relatively unaffected by changes in pH.
An advantage of the invention is the many methods available for synthesis of the new compositions; is the relative ease of doping the new compositions; and
the use of the new composition as catalysts or as precursors of catalysts.
Additional advantages and novel features of the invention are set forth in the description which follows and will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a TEM photomicrograph of Nb-doped TAM-5 made in accordance with the present invention;
FIG. 2 is a TEM photomicrograph of another sample of Nb-doped TAN-5 made in accordance with the present invention;
FIG. 3 is a TEM photomicrograph of Phase 1 of Nb-doped TAM-5;
FIG. 4 is an x-ray diffraction data of Nb-doped TAM-5;
FIG. 5 is a TEM photomicrograph of Phase 3 of Nb-doped TAM-5;
FIG. 6 is an x-ray diffraction pattern for TAM-1;
FIG. 7 is an x-ray diffraction pattern for TAM-2;
FIG. 8 is an x-ray diffraction pattern for TAM-3;
FIG. 9 is an x-ray diffraction pattern for undoped TAM-5;
FIG. 10 is an x-ray diffraction pattern for undoped TAM-5 converted to H + form;
FIG. 11 is an x-ray diffraction of a Nb-doped TAM-5 sample;
FIG. 12 is an x-ray diffraction pattern for TAM-7;
FIG. 13 shows variation of Cs selectively of TAM-5 with pH;
FIG. 14 shows Nb-doped TAM-5 Cs selectivity;
FIG. 15 shows the variation of Cs selectivity of Nb-doped TAM-5 with pH;
FIG. 16 shows the effect of temperature on Cs selectivity of Nb-doped TAM-5;
FIGS. 17 and 18 compare the effectiveness of TAM-5 in removing Cs, Pu and Sr from two defense waste compositions; and
FIG. 19 is an x-ray diffraction pattern of TAM-8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides processes for forming silico-titanate compositions designated herein as TAM-1, TAM-2, TAM-3, TAM-S, TAM-7, and TAM-8, the “TAM” acronym standing for Texas A&M University. The term “silico-titanate” is intended to include silicon titanate, titanium silicate, silicotitanate, TiSi and CST (crystalline silico-titanate). These materials are capable of ion exchange, adsorption, absorption, size selectivity, or other binding. These materials also have the potential of being used as catalysts or catalyst supports combined, for example, with nickel and molybdenum and other metals and compounds (e.g., palladium, platinum, and rhodium) such as disclosed in Ser. No. 07/998,997, entitled Thin Film Hydrous Metal Oxide Catalysts, filed Dec. 31 1992, the teachings of which are incorporated herein by reference. Further, the materials have the capability of acting as ion exchange molecular sieves (size selectivity), as absorbers and adsorbers for a wide range of metals, chemicals, biochemicals, and radioactive materials, for example, radioisotopes of cesium, strontium, plutonium, cobalt, iodine, technetium, rhenium, ruthenium, nickel, cerium, uranium, neptunium, americium, lanthanides, other actinides and the like. The TAM materials are useful in liquid streams, which includes aqueous and non-aqueous liquids, gases and salt solutions.
The electron microscope, spectroscopy, and x-ray diffraction patterns of these novel compositions do not match any known titanate, silicate, titanium silicate, silicon titanate or molecular sieve, thereby indicating new compositions of matter and structures. The materials have a high stability due to their structures and compositions.
Preferred reagents used in the preparation of TAM-1, TAM-2, TAM-3, TAM-5, TAM-7, and TAM-8 include tetraisopropyl titanate (TIPT) as the source of titanium. Other titanium alkoxides can also be used, such as Ti(OR) 4 where R=C x H (2x+1) and x is a positive integer, e.g. CH 3 , C 2 H 5 , C 4 H 9 , C 5 H 11 , titanium halogens, titanium oxides, etc., although any suitable source of Ti may be utilized.
The preferred source of silicon is an alkyl substituent such as tetraethyl orthosilicate (TEOS). Any sources of Si, including colloidal silica, SiO 2 , sodium silicate, other silicon alkoxides, and the like, may also be employed.
Alcohol or aqueous solutions of NaOH, KOH, and tetramethylammonium hydroxide (TMAH), methanol (MeOH or MEOH), are preferably used as the source of OH − , K + , Na + , and NH 4 + ions. Other alkalis such as CSOH, RbOH, LiOH, Ba(OH) 2 , tetraalkylammonium hydroxides, for example, tetrapropyl-ammoniumhydroxide, Groups I and II of the periodic table, and the like, can also be used.
Tetrapropylammonium bromide (TPAB), tetrabutylammonium bromide (TBAB), tetrapentylammonium bromide, and the like, may be used as templates in influencing crystal structure; additionally, such reactants may control pH of the reactant mixture. Other alkylammonium salts, amines, and the like, can also be used.
Because the compositions of the present invention have ion exchange properties, they have a wide range of applications in a variety of fluids, including removal of trace metals, including heavy metal cations and anions, from aqueous and non-aqueous waste, for catalytic reactions and supports for hydrotreating, dehydrogenation, hydrocracking, cracking, oxidation, epoxidation, photochemical, electrochemical, reduction and hydrogenation catalysts, as drying agents and as chemical and biochemical sensors.
As noted above, removal of radioisotopes from waste, in particular radioactive Cs, Pu and Sr, is of tantamount interest. Of the various TAM compositions, TAM-5 indicates the highest radioisotope (e.g., Cs) selectivity and is further improved by doping. Useful dopants include numerous elements and compounds, and groups thereof, (including Groups I (B), III, IV, V (A and B) and VIII (B) of the periodic table) such as Nb, V, Cu, Mn, Fe, Ta, P, and the like. The term “metal dopant” is intended to include all such dopants.
Tables 1-5 list in tubular form the mole ratios, reaction times and temperatures used in the preparation of TAM-1 through TAM-5 (undoped and Nb-doped) and TAM-7 and TAM-8. The process temperature range is between 25° C. to 370° C., preferably between 140° C. to 330° C., more preferably between 140° C. to 250° C., and most preferably between 170° C. to 230° C. Process times are between less than one hour to many days, preferably between one hour and 120 hours, and most preferably less than 100 hours.
TABLE 1
MOLE RATIOS, TIME, AND TEMPERATURES USED IN PREPARING TAM-1
Time,
Temp,
H 2 O/Ti
TMAH/Ti
NaOH/Ti
TBAB/Ti
Si/Ti
MEOH/Ti
TPAB/Ti
Hours
° C.
XRD do, Å
141
0.93
0.93
—
1.04
7.9
0.96
168
170
14.7-15
470
1.30
1.30
—
1.00
11.1
1.30
168
170
14.7-15
144
1.04
1.00
—
1.12
8.8
1.08
70
170
14.7-15
144
1.04
1.00
—
1.12
8.8
1.08
96
170
14.7-15
144
1.04
1.00
—
1.12
8.8
1.08
215
170
14.7-15
156
1.07
1.00
—
1.12
8.8
1.36
90
170
14.7-15
156
1.04
1.00
—
1.12
8.8
1.64
90
170
14.7-15
150
2.50
1.00
—
1.13
21.3
1.08
90
170
14.7-15
152
4.17
1.00
—
1.13
36.5
1.09
90
170
14.7-15
159
1.55
0.50
—
1.14
13.1
2.14
96
170
14.7-15
145
1.55
1.14
—
1.14
13.1
2.14
96
170
14.7-15
162
1.52
0.48
—
1.14
13.0
3.38
96
170
14.7-15
155
1.55
1.20
—
1.15
13.2
3.40
96
170
14.7-15
189
1.58
1.00
2.11
1.16
13.4
—
96
170
14.7-15
206
1.53
1.00
3.18
1.12
13.0
—
96
170
14.7-15
227
1.53
1.00
4.33
1.13
13.0
—
96
170
14.7-15
219
1.50
1.00
3.25*
1.13
12.8
—
96
170
14.7-15
MEOH = Methanol
TPAB = Tetrapropylammonium bromide
TBAB = Tetrabutylammonium bromide
TMAH = Tetramethylammonium hydroxide
*tetrapentylammonium bromide
do = largest observed d-spacing in crystal
TABLE 2
MOLE RATIOS, TIME, AND TEMPERATURES USED IN PREPARING TAM-2 AND TAM-3
Time,
Temp,
XRD
H 2 O/Ti
TMAH/Ti
NaOH/Ti
KOH/Ti
TBAB/Ti
Si/Ti
MEOH/Ti
TPAB/Ti
Hours
° C.
do, Å
TAM-2
37.4
1.39
0.87
—
—
1.0
12.4
0.09
117
200
8.8-8.9
37.4
1.39
0.87
000
000
1.0
12.4
0.09
165
200
8.8-8.9
37.4
1.39
0.87
—
—
1.0
12.4
0.09
237
200
8.8-8.9
556
0.89
0.89
—
—
1.0
7.6
1.00
168
170
8.8-8.9
1060
0.80
0.80
—
—
1.0
6.8
0.80
168
170
8.8-8.9
TAM-3
150
2.69
—
—
—
1.15
22.9
—
96
170
11.6-11.9
TABLE 3
Time,
Temp.,
XRD
H 2 O/Ti
TMAH/Ti
NaOH/Ti
TBAB/Ti
Si/Ti
MEOH/Ti
Hours
° C.
do, Å
165
1.53
1.01
2.08
1.01
13.2
96
170
7.85
150
—
2.69
—
1.15
—
96
170
8.0
183
—
2.65
1.41
1.26
—
114
170
8.0
148
—
1.61
3.17
1.0
—
96
170
7.8
165
—
2.46
—
1.13
—
120
170
7.88
165
—
2.46
—
1.13
—
114
200
7.89
30
—
2.46
—
1.13
—
114
170
7.91
60
—
2.46
—
1.13
—
114
170
7.82
100
—
2.46
—
1.13
—
114
170
7.91
165
—
2.46
—
0.80
—
114
170
7.89
165
—
2.46
—
1.13
—
72
170
7.95
165
—
2.46
—
1.13
—
24
200
7.95
165
—
2.46
—
1.13
—
48
200
7.91
165
—
2.46
—
1.13
—
24
230
7.95
165
—
3.00
—
1.13
—
120
170
7.92
80
—
2.46
—
1.13
—
48
200
8.10
TABLE 4
MOLE RATIOS, TIME, AND TEMPERATURES USED IN
PREPARING Mb-DOPED TAM-5
Time,
Temp.,
H 2 O/Ti
NaOH/Ti
Si/Ti
Mb/Ti
Hours
° C.
X rd do, Å
95
2.59
1.19
0.050
120
170
7.723
95
2.60
1.19
0.17
120
170
7.761
95
2.60
1.19
0.04
120
170
7.790
95
2.60
1.18
1.13
120
170
—
103
2.95
1.36
0.20
120
170
—
130
3.71
1.70
0.50
120
170
—
174
4.97
2.28
1.00
120
170
—
73
4.77
1.45
0.40 (1)
120
170
—
35
4.77
1.45
0.40 (1)
120
170
—
111
3.60
1.57 (2)
0.40
120
170
—
121
3.45
1.59
0.41
24
170
—
121
3.48
1.59
0.40
1
200
7.851
(1) Ti + Mb + partial Na from Hydrous Oxide Si from sodium meta silicate
(2) Ti + Sr + partial Na from Hydrous Oxide.
TABLE 5
MOLE RATIOS, TIME, AND TEMPERATURES USED IN PREPARING TAM-7
Time
H 2 O/Ti
TMAH/Ti
NaOH/Ti
TBAB/Ti
Si/Ti
TPAB/Ti
Hours
Temp ° C.
XRD do, Å
MeOH/Ti
97
2*
0.61
—
0.25
2.42
96
170
9.6-10.7
—
156
3
0.25
2
0.25
—
96
170
9.4-10.2
—
141
3
1.25
2
0.25
—
96
170
8.7-9.6
—
125
3
1.50
2
0.25
—
96
179
9.2-9.9
—
113
3
2.0
—
0.25
2.42
96
170
9.2-10/3
—
FROM HYDROUS GELS
189
1.58
1.0
2.11
1.0
—
96
170
−10
13.4
189
1.58
1.0
2.11
0.5
—
96
170
−10
13.4
189
1.58
1.0
2.11
0.33
—
96
170
−10
13.4
189
1.58
1.0
2.11
0.2
—
96
170
−10
13.4
Note:
TAM-S is prepared in an identical manner, but KOH is substrituted for NaOH.
EXAMPLES
Preparation of TAM-5 (Undoped)
Example I:1
Undoped TAM-5 was prepared by stirring together 2.00 grams of tetraisopropyl titanate (TIPT) and 1.735 grams of tetraethyl orthosilicate (TEOS). 3.03 ml of 6N NaOH and 9 ml H 2 O were added to the TIPT-TEOS mixture. The resulting slurry was stirred and transferred to a stainless steel reactor of sufficient size such that the slurry occupied 80% or less of the reactor volume. The reactor was sealed and heated for 5 days at 170° C. The product was recovered by filtration, washed with H 2 O and acetone to remove excess reactants and facilitate drying. Drying was accomplished in flowing air at room temperature.
Three TAM-5 products had resulting mole ratios as follows: Na:Si:Ti=0.8:0.72:1.0; 0.76:0.72:1.0; 0.91:0.70:1.0, and contained 20.7%, 18.8% and 23% by weight of H 2 O, respectively. All weight loss on heating was due to water loss, and the reaction is reversible. On cooling the water was readily readsorbed.
The amount of Na in the product depended to some extent on how well the samples were washed with water (NaOH forms during washing and is removed). The product is thoroughly defined by a combination of factors including the Si:Ti mole ratio, the alkali hydroxide used, and the mole ratios of other reactants. The reactants do not act independently. It is believed that the structure of the particular TAM compositions involved is governed by the amount of Si in the aqueous phase, in turn depending on the volume of H 2 O and the amount of alkali hydroxide present.
The following are examples of TAM-5 (undoped) which were prepared using autoclaves as well as sources of Si other than TEOS.
In each of Examples I:2-4 and 6-7 a first mixture A and a second mixture B were separately prepared and then each was mixed with the other under the conditions described. Mixture A was prepared by adding 76.56 grams NaOH, then 2318.8 grams of H 2 O to a beaker and stirring to dissolve the NaOH. Mixture B was prepared by adding 220.99 grams of tetraisopropyltitanate (TIPT) then 183.64 grams of tetraethyl orthosilicate (TEOS) to a beaker and stirring the contents. In Example I:5 a portion of the 2318.8 grams of H 2 O was reserved from being added to Mixture A, and after mixtures A and B were mixed, the reserved H 2 O was added, as described in that example.
Example I:2
Mixture B was poured into Mixture A slowly while stirring. A 10° C. rise of temperature was observed.
The reaction mixture was placed in an autoclave and a leak test was performed. The mixture was heated to 170° C. At 170° C., the pressure gauge indicated 150 psig. After 120 hours the heater was turned off. A fan was used to help the reactor cool down and the mixture was left to set over night. Thereafter, the supernate was removed, top, middle, bottom, and bulk particles respectively. Particles were filtered and washed with H 2 O three times, then with acetone once. The particles were dried in air.
The resulting mole ratios were Na:Si:Ti=0.99:0.74:1.00.
Example I:3
Mixture A was added to the autoclave reactor and heated to 148° C., then the heater was turned off and Mixture B was added by gravity feed while agitating the reactor mixture. The heater was then turned on and the reaction mixture was heated from 148° C. to 170° C. and agitated at 200 rpm. After 72 hours the heater was turned off and the reactor cooled down naturally. The supernate and bulk particles were removed respectively. The bulk particles were uniform in size. The particles were filtered and washed with H 2 O three times, then with acetone once, then dried in air. The resulting mole ratios were Na:Si:Ti=0.97:0.76:1.00.
Example I:4
Mixture A was added to the autoclave reactor and heated to 140° C., then the heater was turned off and Mixture B added while agitating the reactor mixture at 45 rpm. The reactor mixture was then heated from 145° C. to 170° C. After temperature reached 170° C. agitation of the reaction mixture was increased to 200 rpm for 10 minutes, then the agitation was stopped. After 72 hours the heater was turned off and the reaction mixture was left to cool down naturally. The supernate, bottom and bulk particles respectively were removed. The particles were filtered and washed with H 2 O three times, then with acetone once, then dried in air. The resulting mole ratios were Na:Si:Ti=0.95:0.90:1.00.
Example I:5
In a beaker, weigh 76.56 gram NaOH, then add 762.49 gram H 2 O. Stir it to dissolve NaOH (Mixture A′). In a beaker, weigh 220.99 gram TIPT, then add 183.64 gram TEOS. Stir it (Mixture B′).
Mixture A′ was fed into autoclave, then Mixture B′ was fed in at 27.5° C. at 80 rpm. Feed the rest of H 2 O (1556.3 gram) at 200 rpm. Turn on the heater to 170° C. After ten minutes, turn the rpm back to 80. Keep agitating. After 120 hours, turn off the heater and agitator. Let the reactor cool down naturally. Remove supernate, bottom and bulk particles respectively. Filter the particles and wash with H 2 O three times, then with acetone twice. Dry it in air. The resulting mole ratios were Na:Ti=1.07-1.21:1.00 and Si:Ti=0.77-0.93:1.00.
Example I:6
Mixture A was fed into an autoclave, then Mixture B was fed in at 26° C. at 100 rpm. N 2 was fed into the reactor to increase the pressure to 250 psig. The heater was turned up to reach a reaction mixture temperature of 170° C., then the agitator was turned off. After 120 hours the reactor heater was turned off and the reactor cooled down naturally. The supernate, top, middle, bottom and bulk particles respectively were removed. The particles were rinsed with water three times (2 grams H 2 O/1 gram particle each time), then rinse with acetone three times (2 grams acetone/1 gram particles). Thereafter the particles were dried in air. The resulting mole ratios were Na:Ti=0.78-0.98:1.00 and Si:Ti=0.69-0.96:1.00. The average mole ratio was Na:Si:Ti=0.87:0.82:1.00.
Example I:7
Mixture A was fed into an autoclave, then Mixture B was fed in at 27° C. at 150 rpm. The reactor heater was turned on and agitation of the reactor contents was raised to 200 rpm. The wall temperature between the autoclave and the heat jacket was controlled at 228° C., the reactor contents controlled to a temperature of 176° C. After 120 hours, the heater was turned off but agitating continued while the reactor cooled down naturally. Change out the product from the bottom. Filter the product. Wash the filtercake with H 2 O three times (100 cc H 2 O/30 gram solid each time). Then wash with acetone three times: 100 cc acetone/30 gram solid each time. The resulting mole ratios were Si:Ti=0.84-0.95:1.00 and Na:Ti=0.90:1.00.
Examples I:8-12
Examples I:8-12 present other variations in the preparation of a TAM-5 composition as described.
Example I:8
In a beaker, weigh 241.16 gram NaOH, then add 1560.8 gram H 2 O. Stir it to dissolve NaOH (Mixture A). In a bucket, weigh 578.47 gram TEOS and 696.12 gram TIPT. Stir it. (Mixture B). Feed Mixture A into autoclave, then feed Mixture B at 35° C. at 200 rpm. Turn on the heater. Control the wall temperature between autoclave and heat jacket at 220° C. bulk temperature to rise to 174° C. Keep agitating. After 120 hours, turn off the heater but keep the agitation and let the reactor cool down naturally. Samples taken at 12 hours, 24 hours, 48 hours, 72 hours and 96 hours are taken. Filter the product. Wash the filtercake with H 2 O three times (100 cc H 2 O/30 gram solid each time). Then wash with acetone three times (100 cc acetone/30 gram solid each time). The resulting mole ratios were Na:Ti=0.93-1.67:1.00 and Si:Ti-0.86-1.05:1.00.
Example I:9
In a beaker, weigh 1.11 gram NaOH, than add 9.99 gram methanol. Stir it to dissolve NaOH (Mixture A). In a plastic tray, weigh 3.52 gram TIPT, then add 2.92 gram TEOS. Stir it (Mixture B). Take 5.85 Mixture B and add it to Mixture A slowly while agitating (Mixture C). In a beaker, weigh 4.06 gram H 2 O then add 35.64 gram acetone. Stir it (Mixture D). Add Mixture D into Mixture C slowly while agitating. Let the reaction mixture settle for 0.5 hours. Decant the supernate. Add 33.52 gram H 2 O to solid phase, stir it, then transfer it to a reactor. After 120 hours at 170° C. remove from the reactor and quench it. Filter the product and wash with H 2 O three times then with acetone once. Dry it in air. Mole ratios were not determined.
Example I:10
In a beaker, weigh 0.65 gram NaOH, then add 19.06 gram H 2 O. Stir it to dissolve NaOH (Mixture A). Add 2.55 gram LUDOX SM (30% SiO 2 0.56% Na 2 O) into Mixture A slowly while agitating (Mixture B). Add 3.20 gram TIPT into Mixture B slowly while agitating. Move reaction mixture into a small bottle reactor. Put reactor into an oven pre-set at 170° C. After 114 hours, remove from reactor. Quench it. Filter it and wash with H 2 O three times, then with acetone once. Dry it in air. The resulting mole ratios were Na:Si:Ti=0.84:0.83:1.00.
Example I:11
In a beaker, weigh 0.67 gram NaOH, then add 19.04 gam H 2 O. Stir it to dissolve NaOH (Mixture A). Add 0.47 gram SiO 2 (Davison Silica Gel Catalyst Grade 952) into Mixture A. Agitate it for 10 minutes (Mixture B). Add 1.92 gram TIPT into Mixture B slowly while agitating. Move reactor mixture into a small bottle reactor. Put reactor into an oven pre-set at 170° C. After 114 hours, remove from the reactor. Quench it. Filter it with H 2 O three times, then with acetone once. Dry it in air. The resulting mole ratios were Na:Si:Ti-0.89:0.78:1.00.
Example I:12
In a beaker, weigh 0.43 gram NaOH, then add 18.02 gram H 2 O. Stir it to dissolve NaOH (Mixture A). Add 1.73 gram sodium silicate solution (percentages by weight) into Mixture A slowly while agitating for 10 minutes (Mixture B) Add 1.92 gram TIPT into Mixture B slowly while agitating. Move reaction mixture into a small bottle reactor. Put reactor into an oven pre-set at 170° C. After 114 hours, remove from the reactor. Quench it. Filter it with H 2 O three times, then with acetone once. Dry it in air. The resulting mole ratios were Na:Si:Ti=0.86:0.76:1.00.
Preparation of TAM-1, TAM-2, TAM-3, TAM-7 AND TAM-8: Example II
Preparation of TAM-1, TAM-2, TAM-3, TAM-7 and TAM-8, parallels the methods employed in preparation of undoped TAM-5.
TAM-5 (undoped) and TAM-7 compositions were also prepared using amorphous powder serving as the sources of Ti, Si and Na. The amorphous powder is made from TIPT, TEOS and a methanol solution of NaOH.
Preparation of TAM-5 (Nb-doped): Example III
Most of the Nb-doped TAM-5 compositions were from TIPT, TEOS, an aqueous solution of NaOH and pentaethyl niobate (PEN).
One method of preparation of Nb-doped TAM-5 differs from that used for undoped TAM-5 only in the addition of Nb in the alkoxide (pentaethyl niobate or niobium ethoxide, hereinafter PEN). Nb was added without changing the Na, Si or H 2 O amounts used in the undoped TAM-5 preparation. Other Nb alkoxides or sources of niobium, such as Nb 2 O 5 , can also be used.
In the following examples III: 1-7 of prepared compositions, the primary variable was Nb content: charge mole ratios are H 2 O:Na:Si:(Ti+Nb)=86:2.46:1.13:1.0 for all samples. The mount of H 2 O was assumed to equal volumes of 6N NaOH+H 2 O added.
Each of Examples III:1-7 were prepared by first mixing with 1.82 grams of tetraethyl orthosilicate (TEOS) various gram amounts of tetraisopropyltitanate (TIPT) and pentaethyl niobate in an autoclave reactor, as reported in Table III:1-7. Thereafter to such mixture 3.17 ml of 6 N NaOH and 8.8 ml H 2 O was added with stirring and thereafter the reaction mixture was heated to 170° C. and so maintained under such heat and stirring for 120 hours. The composition of the reaction charge and the weight of recovered product is reported in Table III:1-7.
TABLE III
1-7
Wt. Re-
Nb:Ti
EXPL.
TIPT(g)
PEN (g)
TEOS (g)
covered
Recovered
III:
Charge
Charge
Charge
Product
Product
1
2.00
0.242
1.82
1.38
0.1
2
1.83
0.400
1.82
1.35
0.2
3
1.69
0.550
1.82
1.34
0.3
4
1.57
0.685
1.82
1.27
0.4
5
1.46
0.797
1.82
1.36
0.5
6
1.25
1.020
1.82
1.35
0.75
7
1.09
1.190
1.82
1.46
1.00
In Example IV:1-2, two further examples of Nb doped Si:Ti compositions of TAM-5 were made (note: hydrous niobium pentoxide, a commercial source, was used as the source of niobium), as follows:
Example IV:1
In a beaker, weigh 2.40 grams NaOH, weigh 1.29 grams Nb 2 O 5 , then add 12.25 grams H 2 O. Mix it for 10 minutes. This is Mixture A. In a plastic tray, weigh 7.59 grams TIPT, add 6.27 grams TEOS. Mix it. This is Mixture B. Add 12.60 grams Mixture B into Mixture A slowly while stirring. It takes 3 minutes to add Mixture B. Mix it for 5 minutes after feeding. This is Mixture C. Add 59.76 grams H 2 O into Mixture C. Move the mixture into a 100 ml autoclave, and leak test. Turn on the heater and agitator. It takes about 1 hour to raise the temperature to 230° C. After 60 hours, turn off the heater and agitator. Take off the heater jacket, use a fan to help cool down the reactor. Filter the product. Wash it with water 3 times, 50 ml each time, then wash with acetone 3 times, 50 ml each time. Recovered 4.93 grams product with a mole ratio of Nb:Ti=0.4:1.
Example IV:2
In a beaker, weigh 76.11 grams NaOH, weigh 40.91 grams Nb 2 O 5 , then add 380.55 grams H 2 O. Mix it for 10 minutes. This is Mixture A. In a plastic container, weigh 218.82 grams TIPT, add 180.77 grams TEOS. Mix it. This is Mixture B. Add Mixture B into Mixture A slowly while stirring. It takes 12 minutes to add Mixture B into Mixture A. Mix it for 10 minutes after feeding. This is Mixture C. Add 1902.83 grams H 2 O into mixture C. That takes 20 minutes. Mix it for 10 minutes. Move the reactant mixture into 1 gallon autoclave. Leak test. Turn on the heater and agitator. It takes about 1 hour to raise the temperature to 205° C. After 120 hours, turn off the heater and agitator. Use a fan to help cool down the reactor. Filter the product in two batches, approximately ½ of the product in each batch. Wash each batch with water 3 times, 200 ml each time, then wash with acetone 3 times, 200 ml each time. Total recovered product was 159.61 grams for both filtrations with a mole ratio of Nb:Ti=0.41:1.
Preparation of Ti—Nb and Ti—Nb—Si Hydrous Metal Oxide Precursors: Example V:1-2
Yet another method for producing either undoped TAM-5 or Nb-doped TAM-5 involves the preparation of solid hydrous metal oxide materials. To these hydrous metal oxide precursors were added water, NaOH and additional Si in the form of sodium metasilicate (SMS) to provide proper stoichiometry.
These mixtures were then heated hydrothermally in a reactor to produce undoped TAM-5 or Nb-doped TAM-5.
This particular method allowed more TAM-5 to be produced per unit reactor volume which is of significant economic importance. Perhaps more importantly, the use of hydrous metal oxides as precursors for TAM-5 materials permits the formation of this film on inert supports as disclosed in application Ser. No. 07/998,997, entitled Thin Film Hydrous Metal oxide Catalysts, Dosch, et al., filed Dec. 31, 1992. For example, it is well known to coat high surface area silica gel spheres with thin films (i.e. <10 nm) of hydrous metal oxide materials. Such a material coated with a TAM-5 precursor hydrous metal oxide, when heated hydrothermally, results in a material with an engineering form usable in typical ion exchange units having the Cs adsorption properties of TAM-5 while actually containing only a small fraction of TAM-5, which is a far more expensive material. This thin film preparation approach is applicable to all TAM compositions.
Example V:1
Ti—Nb Hydrous Metal Oxide (Na 0.7 Toi 1.0 Nb 0.4 )
To 35.6 gram of TIPT and 15.5 gram PEN (30% Nb) was added to 35.2 gram of 9.94% NaOH in MeOH. The resultant mixture was mixed well and hydrolyzed in 250 ml of acetone and 25 ml of H 2 O, and thereafter vacuum dried. The product was sieved with −60 mesh and 23 gram of product was recovered. The product composition was 18.43% Nb, 23.76% Ti and 7.98% Na. Subsequently, a film is formed on a silica pellet to provide Si for producing a TAM-5 film or Si is added as in the Example immediately below.
Example V:2
Ti—Nb—Si Hydrous Metal Oxide (Na 0.7 Ti 1.0 Nb 0.4 Si 1.4 )
To 36.6 gram of TIPT, 15.5 gram PEN (30% Nb) and 36.4 gram TEOS was added 35.2 gram of 9.94% NaOH in MeOH. The resultant mixture was mixed well and hydrolyzed in 250 ml of acetone and 25 ml of H 2 O, and thereafter vacuum dried. The product was sieved with −60 mesh and 28.9 gram of product was recovered. The product composition was 11.58% Nb, 14.92% Ti, 5.01% Na and 12.22% Si.
Preparation of TAM-5 (Nb-doped) Using Hydrous Metal Oxides: Examples VI:1-5
Example VI:1
To 2.0 gram Ti—Nb precursor (above) and 4.1 gram sodium metasilicate (SMS) were added 10 ml H 2 O and 1.92 ml 6N NaOH. The resultant mixture was heated in a reactor at 170° C. for 120 hours. 2.67 gram product was recovered after H 2 O and acetone washing and air drying. Reactant compositions were as follows:
H 2 O:Na:Si:Nb:Ti=73:4.77:1.45:0.4:1.0
H 2 O:Na:Si:Nb+Ti=52:3.4:1.04:1.0
Example VI:2
To 4.0 gram Ti—Nb precursor (above) and 8.2 gram SMS were added 3.84 ml 6N NaOH and 4 ml H 2 O. The resultant mixture was heated in a reactor at 170° C. for 120 hours. 4.65 gram of product was recovered after H 2 O and acetone washing and air drying. Reactant compositions were as follows:
H 2 O:Na:Si:Nb:Ti=35:4.77:1.45:0.4:1.0
H 2 O:Na:Si:Nb+Ti=25:3.4:1.04:1.0
Example VI:3
To 2 gram of Ti—Si—Nb precursor (above) and 0.303 gram SMS were added 9.34 ml H 2 O and 2.66 ml 6N NaOH. The resultant mixture was heated in a reactor at 170° C. for 120 hours. 1.71 gram product was recovered after H 2 O and acetone washing and air drying. Reactant compositions were as follows:
H 2 O:Na:Si:Nb:Ti=lll:3.6:1.57:0.4:1.0
H 2 O:Na:Si:Nb+Ti=79:2.57:1.12:1.0
Example VI:4
To 4 gram Ti—Si—Nb precursor (above) and 0.606 gram of SMS were added 6.68 ml H 2 O and 5.32 ml 6N NaOH. The resultant mixture was heated in a reactor at 170° C. for 120 hours. 3.59 gram product was recovered after H 2 O and acetone washing and air drying. Reactant compositions were as follows:
H 2 O:Na: Si:Nb:Ti=60:3.6:1.57:0.4:1.0
H 2 O:Na: Si:Nb+Ti=43:2.57:1.12:1.0
Example VI:5
To 6 gram of Ti—Si—Nb precursor (above) and 0.909 gram SMS were added 7.98 ml 6N NaOH and an additional 2 ml of H 2 O (due to reactor size limitations). The resultant mixture was heated at 170° C. for 120 hours. 5.66 gram product was recovered after H 2 O and acetone washing and air drying. Reactant compositions were as follows:
H 2 O:Na:Si:Nb:Ti=36:3.6:1.57:0.4:1.0
H 2 O:Na:Si:Nb:Ti=26:2.57:1.12:1.6
Characterization of the TAM Materials TAM-1
A transmission electron microscope (TEM) examination of TAM-1 revealed that the composition comprised at least four phases. Phase 1 comprises small, flake-like crystalline platelets which, in the aggregate, contain titanium (Ti), oxygen (0), silicon (Si) and sodium (Na) as determined by an energy dispersive x-ray spectroscopy (EDS) analysis of Phase 1. Phase 2 comprises large very-thin parallelepiped platelets comprised primarily of Si and 0 with a small amount of Ti and possibly a trace of Na, as revealed by an EDS analysis. An EDS analysis of Phase 4 revealed an amorphous Si oxide with a trace of Ti. It is solid, not porous, with an interconnected ball-like morphology. Phase 3 of the TAM-1 composition as determined by TEM observation, is an amorphous, porous, ball-like material comprising high Ti, Si, 0 and some Na.
In TAM-1 at higher magnification, Phase 1 appears to be similar to a clay-like material. Measurement of the lattice plane spacings shows them to be about 15 Å. This is in good agreement with x-ray diffraction data for clay-like materials. It is believed that Phase 1 of the TAM-1 composition provides the ion exchange and size selectivity properties of TAM-1.
FIG. 6 is an x-ray diffraction pattern using CuKα x-rays for TAM-1. Table 6 lists 2-theta (degrees) , d-spacing (Angstroms) and relative intensities of the pattern.
TABLE 6
Composite List of Principal X-Ray
Diffraction Pattern Peaks for TAM-1
2-theta
d-spacing
Relative
Line No.
(degrees)
(Angstroms)
Intensities
1
5.9
15
100
2
7.6
11.7
54
3
9.4
9.4
33
4
11.6
7.6
25.4
6
23.1
3.85
32
7
23.85
3.73
21
8
24.6
3.6
21
9
28.3
3.16
23
10
48
1.88
12
TAM-2
A TAM observation of the TAM-2 composition showed that it contains at least four phases; the phase mixture is similar to but not the same as that of TAM-1. Phases 1, 2, and 3 of TAM-2 are the same as for Phases 1, 2 and 3 of TAM-1, as established by energy dispersive x-ray spectroscopic analysis, A TEM examination of Phase 4 of TAM-2 revealed it to be a porous interconnecting phase. It is the least prevalent phase of TAM-2. An EDS analysis of Phase 4, showed high Ti, Si and 0, but no Na. This phase was not observed in TAM-1.
FIG. 7 is an x-ray diffraction pattern for TAM-2. Table 7 lists 2-theta, d-spacing and relative intensities of the pattern.
TABLE 7
Composite List of Principal X-Ray
Diffraction Pattern Peaks for TAM-2
2-theta
d-spacing
Relative
Line No.
(degrees)
(Angstroms)
Intensities
1
10.18
8.68
100
2
21.6
4.1
21
3
24.7
3.6
42
4
28
3.18
68
6
33.7
2.65
41
7
40.06
2.25
38
8
47.88
1.9
64
TAM-3
A TAM examination showed at least two phases for TAM-3. Phase 1 is amorphous and appears to be as same as Phase 4 in TAM-1, i.e. silica gel-appearing spheres which contain only Si and 0, as shown by an EDS analysis. Phase 2, the primary phase, appears to contain Ti, 0 and Si, as shown by EDS analysis.
Higher magnification TEM examination of TAM-3 showed what appears to be silica-gel spheres which have coalesced forming a chain-shaped structure. Phase 2 of TAM-3 appears to form within the chain-shaped structure. For example, an energy dispersive x-ray spectroscopic analysis (EDS) of the outer amorphous surface of the chain-shaped structure reveals only the presence of Si and 0 with a trace of Ti. On the other hand, an EDS analysis of the internal layered rib shows that the layered material found in the center of the chain-like structure contains 0, Si, Ti in roughly equal amounts. The lattice spacing of Phase 2, 10 Å-11 Å, agree with d-spacings observed by x-ray diffraction. It is this phase that is believed to be the source of ion exchange and size selectivity properties of TAM-3.
FIG. 8 is an x-ray diffraction pattern for TAM-3. Table 8 lists 2-theta, d-spacing and relative intensities of the pattern.
TABLE 8
Composite List of Principal X-Ray
Diffraction Pattern Peaks for TAM-3
2-theta
d-spacing
Relative
Line No.
(degrees)
(Angstroms)
Intensities
1
7.5
11.80
100
2
15.3
5.78
20
3
25.5
3.47
20
4
38.2
2.32
15
6
48.2
1.84
25
7
62.5
1.42
15
8
82.5
1.07
10
TAM-5
A TEM analysis of TAM-5 revealed it to be a 99% single phase composition. This primary phase also appears to be an aggregate of small crystalline cuboidal particles. A very minor phase appears to comprise shard-like particles many microns in length that degenerate under the TEM electron beam. An EDS analysis of the primary phase of TAM-5 revealed Ti, 0, Si and Na which is in direct agreement with bulk elemental analyses.
FIG. 1 is a photomicrograph of a sample (like example III:1) of Nb-doped TAM-5. This sample has a Nb:Ti mole ratio of 0.05. Overall reactant mole ratios were H 2 O:NaOH:Si:Nb:Ti=95:2.59:1.19:0.05:1.0. This composition is essentially a single phase silico-titanate with minor amounts of Nb, as shown on EDS analysis of aggregated particles. Morphology is cuboidal or otherwise blocky shaped. The largest lattice spacing measured both in selected area diffraction patterns and fringes in high magnification photomicrographs approximated 7.5 Å. This spacing is in good agreement with x-ray diffraction data. The Nb is either dissolved in or substituted in the crystalline lattice as no Nb-rich phases are observed. With the exception of the presence of Nb as shown by the EDS analysis, there is nothing in the TEM examination to differentiate this composition from undoped TAM-5.
FIG. 2 is a photomicrograph showing a second sample (like example III:6) of Nb-doped TAM-5. This composition contains at least three phases. Phase 1 is the major phase and is the same silica-titanate occurring in FIG. 1, but contains about four times more Nb, either dissolved or substituted in the crystalline lattice. Phase 1 also has a widely varying Na content as shown by EDS analyses. Many of the particles are cuboidal as shown in FIG. 3, although less in number than in the sample of FIG. 1 . The mean particle size, however, is larger than that of the sample shown in FIG. 1 . Since the reactants for this sample contain approximately eight times more Nb relative to Ti than did the sample of FIG. 1, and the product of this sample contained only about four times more Nb, the conclusion is suggested that about half of the Nb is contained in other phases. Indeed, Phase 2, analyzed by TEM is a Nb—Si—O rich phase with much smaller Ti content than Phase 1. Phase 2, therefore, is assumed to be Nb-silicate containing only a small amount of Ti in solution, as shown by an EDS analysis. It is estimated that Phase 2 contains 10-15% by volume of TAM-5 material. The morphology is flake-like having a layered structure with layer plane spacings of about 11.3. Å, as determined by high magnification photomicrographs. FIG. 4, showing x-ray diffraction data of this TAM-5 composition sample, show the largest d-spacings to be about 7.8 Å. The fact that Phase 2 was not detectable using x-ray diffraction suggests that the 10-15% by volume estimate may be too high. Another minor phase, Phase 3, (1-2% by volume, maximum) was detected. The particles are elongated and cigar shaped; this phase is assumed to be an oxide of Nb. Phase 3, as shown by EDS analyses, contains high Nb and 0 with small amounts of Ti and Si and variable Na.
The phase in this particular Nb-doped TAM-5 composition sample which is believed to provide high Cs selectivity in the presence of Na is Phase 1. This is believed true because: 1) increasing the Nb:Ti mole ratio in the reactants above approximately 0.4 does not result in enhanced Cs selectivity, but rather the opposite, and 2) a composition prepared using an undoped TAM-5 preparation where Nb was substituted for Ti exhibited no Cs selectivity.
FIG. 9 is an x-ray diffraction pattern of an undoped TAM-5 sample; FIG. 10 is an x-ray diffraction pattern of undoped TAM-5 converted to H + form; FIG. 11 is an x-ray diffraction pattern of an Nb-doped TAM-5 sample.
TABLE 9
Composite List of Principal X-Ray Diffraction
Pattern Peaks for TAM-5 and Nb-doped TAM-5
2-theta
d-spacing
Relative
Line No.
(degrees)
(Angstroms)
Intensities
1
11.34
7.80
100
2
14.75
6.00
24
3
17.64
5.02
18
4
26.48
3.36
21
5
27.44
3.25
27
6
33.90
2.64
16
7
34.30
2.61
16
8
36.22
2.48
11
TAM-7
A TEM examination of a TAM-7 composition revealed that it contains a major and minor phase, denoted Phase 1 and Phase 2, respectively. Phase 1 is observed as aggregates of thin flake-like platelets having a layered structure; it appears identical to the major phase in TAM-2. An EDS spectra showed the flakes to contain high Ti and 0 and lesser Na and Si, along with a trace of K not observed in TAM-2.
Phase 2 of TAM-7, by TEM examination, comprises a solid ball structure, frequently connected but sometimes isolated. An EDS spectra of Phase 2 indicated an Si oxide with a small amount of Ti in solution. This phase was observed in TAM-1 and TAM-3 but not in TAM-2.
FIG. 12 is an x-ray diffraction pattern for TAM-7. Table 10 lists 2-theta, d-spacing and relative intensities of the pattern.
TABLE 10
Composite List of Principal X-Ray
Diffraction Pattern Peaks for TAM-7
2-theta
d-spacing
Relative
Line No.
(degrees)
(Angstroms)
Intensities
1
9.3
9.42
100
2
23.4
3.8
76
3
25.4
3.5
62
4
28.7
3.1
74
6
48.4
1.88
78
7
63.4
1.46
47
8
82.5
1.168
27
TAM-8
FIG. 19 is an x-ray diffraction pattern for TAM-8. Table 10b lists 2-theta, d-spacing and relative intensities of the pattern.
TABLE 10b
Composite List of Principal X-Ray
Diffraction Pattern Peaks for TAM-8
2-theta
d-spacing
Relative
Line No.
(degrees)
(Angstroms)
Intensities
1
11.5
7.70
100
2
20.0
4.43
15
3
21.2
4.17
10
4
28.5
3.11
80
6
33.0
2.68
35
7
35.0
2.53
20
8
37.0
2.39
20
9
48.0
1.84
20
10
60.0
1.48
10
Surface Area and Pore Distribution
The TAM compositions herein disclosed are further characterized by their surface area and pore size distribution relative to other known compositions. The nitrogen BET (Brauneauer-Emmett-Teller) method of measuring surface area is a well accepted technique for use with solids with surface areas greater than about 10 m 2 /gram. Pore sizes and distributions are a less rigorous parameter for materials characterization. Nevertheless, when both surface area measurement, average pore size and pore size distribution parameters are taken together, definite trends can be established.
The following Table 11 compares a TAM-5 composition with various clays (typically layered “two-dimensional” crystallographic structures) and zeolites (typically “three-dimensional” crystallographic structures). The data clearly shows that TAM-5 has a BET surface area higher than typical clays but significantly lower than zeolites. The zeolites are further characterized by having a large fraction of surface area characterized by micropores, while TAM-5 has little microporosity. Further, TAM-5 has a much larger total pore volume than either the clays or the zeolites.
TABLE 11
SURFACE AREA AND POSRE DISTRIBUTION DATA FOR A TAM-5
MATERIAL AND SOME TYPICAL CLAYS AND SYNTHETIC
ZEOLITES
BET
Mesopore
Micro
Average
SA,
SA,
SA,
Total Pore
Mesopore
m 2 /g (1)
m 2 /g (2)
m 2 /g (3)
Volume,
Diam.,
(1)
(2)
(3)
cc/g
Å
SML TAM-5 #70
133
130
3
0.86
252
CLAYS
Kaolinite-KGA
21
21
0
0.27
522
Bentonite-SA3-1
72
41
31
0.16
92
Gentonite-STX-1
68
68
0
0.23
133
ZEOLITES
ZSM-5
316
55
261
0.23
30
HY
427
65
362
0.34
32
Silicate
352
51
301
0.23
26
(1) Total BET surface area
(2) Surface areas of mesopores defined here as pores with diameters in the range of about 20-600 Å.
(3) Surface area of micropores defined here as pores with diameters less than 20 Å.
Composition of TAM Silicon Titanates
Tables 12 and 13 are results of analyses of TAM-1, TAM-2, TAM-3, TAM-5, Nb-doped TAM-5 and TAM-7. While photomicrographs clearly show multiple phases in TAM-1, TAM-2, TAM-3 and TAM-7, quantitative determination of the compositions and amounts of the active phases of these compositions is not possible. The property of interest of the active phases is the molecular structure of such phases or their performance as a catalyst support or heavy metal absorber. For example, the active phase in a series of TAM-1 samples could have exactly the same composition, while the overall composition of each TAM-1 sample could vary considerably. Therefore, denoting the particular TAM composition in terms of mole ratios of reactants is the preferred nomenclature for the composition inasmuch as it affords reliable reproduction capability. Expressing the TAM compositions in weight percent is of little value inasmuch as the water content varies considerably due to the washing and drying processes, as well as the hygroscopic nature of the compositions. Alkali metal content also varies dependent upon the washing and drying processes. In catalysis and Cs adsorption/ion exchange uses, for example, TAM-5 is equally effective even if all alkali metal is removed prior to use.
TAM-5 and Nb-doped TAM-5 each essentially contain only a single phase; therefore, such phase is the “active” phase.
TABLE 12
Elemental Analyses of TAM materials
Na,
Nb,
H 2 O,
wt %
K,wt %
Si,wt %
wt %
Ti,wt %
wt %
TAM-1
6.1
NA
13.8
NA
20.8
ND
TAM-2
5.9
NA
15.7
NA
28.3
ND
TAM-3
NA
NA
13.8
NA
21.5
ND
TAM-5 (A)
9.9
NA
10.9
NA
25.7
20.7
(B)
9.7
NA
11.2
NA
26.4
18.8
(C)
10.4
NA
10.5
NA
23.8
23.0
Nb-Doped TAM-5
(A)
ND
NA
8.9
4.9
19.2
ND
(B)
ND
NA
8.0
13.9
15.6
ND
(C)
ND
NA
7.9
21.8
9.6
ND
TAM-7
4.54
NA
6.61
NA
35.6
ND
TAM-8
NA
4.12
5.3
NA
38.8
ND
NA = not added
ND = not determined
TABLE 13
Mole Ratios in TAM Materials
Na:
K:
Si:
Nb:
Ti:
TAM-1
0.60
0
1.13
0
1.0
TAM-2
0.44
0
1.00
0
1.0
TAM-3
0
0
1.09
0
1.0
TAM-5
0.80
0
0.72
0
1.0
0.76
0
0.72
0
1.0
0.91
0
0.75
0
1.0
Nb-DOPED TAM-5
ND
0
0.79
0.13
1.0
ND
0
0.87
0.46
1.0
ND
0
1.41
1.17
1.0
TAM-7
0.27
0
0.22
0
1.0
TAM-8
0
0.13
0.24
0
1.0
ND = not determined
Cs, Pu, and Sr Adsorption
As noted above, the TAM crystalline titanates have been found to be very efficient in removing radioisotopes of Cs, Sr and Pu from radioactive or defense waste. Removal of such radioactive matter is extremely important as it would allow such defense waste to be stored as a dry chemical rather than as a liquid radioactive waste requiring isolation for safety. Ion exchange materials which can differentiate and separate radioactive ions by virtue of ionic size rather than charge would provide a more efficient separation vehicle. The TAM compositions provide such ionic separation of Cs from Na by virtue of size selectivity.
Of the TAM compositions, TAM-5 is superior for removing the radioactive isotope of Cs from Na. TAM-5 compositions having a k d of 4900, for example, separates one atom of Cs for every 2×10 5 atoms of Na. As a basis for comparison a k d of 84 has been reported for a commercial organic ion-exchange resin.
Further, development of TAM-5 compositions comprising a sample size of 33 (discussed in the following paragraph) has yielded an average k d of 58 with a standard deviation of ±15. The simulated radioactive waste composition comprised 5.7M Na + -O.6M OH − and 100 ppm Cs. The k d values of all compositions tested were within two standard deviations.
As disclosed earlier, the initial “baseline” reactant compositions for TAM-5 have the following stoichiometry in mole ratios: H 2 O:OH − (Na):Si:Ti=165:2.46:1.13:1. The initial “baseline” preparations included heating at 170° C. for 120 hours; the H 2 O:Ti,OH—:Ti and Si:Ti mole ratios were varied in the ranges of 30-165, 2.0-3.0, and 0.8-1.5, respectively. The temperature range was 140-230° C., the reaction time range was 24-192 hours, and batch sizes ranged from 1 gram to 200 grams. The initial “baseline” sources of Ti, Si and OH − were tetraisopropyl titanate (TIPT), tetraethyl orthosilicate (TEOS) and sodium hydroxide (NaOH), respectively. Less expensive silicon dioxide or Ludox colloidal silica could be substituted for TEOS, and hydrous oxides of Ti and Si could also be used.
Cs selectivity of TAM-5 is drastically affected by pH, as shown in FIG. 13, where Cs k d values decrease significantly with increasing pH. Also shown are Cs k d values using the inorganic zeolite UOP IE-96 and BSC organic resin. At a pH value of less than 12, TAM-5 is clearly several orders of magnitude more effective than either the zeolite or the resin. At pH values of greater than 12, TAM-5 is about twice as effective as the zeolite but not as effective as the resin.
Also, as earlier disclosed, it was noted that Nb added as pentaethyl niobate (PEN) and niobium oxide to TAM-S dramatically increased Cs selectivity. FIG. 15 shows the Cs selectivity of Nb-doped TAM-5 over a range of pH values. In particular Cs selectivity at high pH was greatly improved.
As shown in FIG. 14, the Cs distribution coefficient depends on the mole ratio of Nb:Ti in the reactants. Results for the zeolite and BSC resin are also included in FIG. 14 .
As disclosed earlier, it is believed Nb substitutes into the TAM-5 structure causing small changes in structure. Nb in excess of that which goes into the TAM-5 structure further comprises two Nb-rich phases, neither of which is believed to absorb Cs in a high Na matrix. The high Cs selectivity of Nb-doped TAM-5 in a strongly basic solutions with high Na content makes these Nb-doped TAM-5 compositions unique.
The presence of Nb dopant also “stabilizes” the TAM-5 structure at high temperatures. For example, an undoped TAM-5 sample composition with a Cs K d of 72 in a 5.7M Na-0.6M OH − stimulant composition was heated at 100° C. and 275° C., resulting in the Cs k d dropping to 58 and 22, respectively. In contrast thereto, FIG. 16 reveals the much higher Cs k d values attained using Nb-doped TAM-5. Temperatures up to 275° C. have little effect on Cs selectivity. Higher temperature result in decreased k d values; nevertheless, the k d values of Nb-doped TAM-5 are still higher than the UOP zeolite. Temperature stability is important not only with regard to Cs selectivity but in catalyst support use and in processes to convert TAM powders to extrudates, pellets, spheres and the like.
FIGS. 17 and 18 reveal the effectiveness of TAM-5 in removing Pu, Cs and Sr from two synthetic defense waste compositions, respectively. The results show that TAM-5 is comparable to or better than the zeolites (UOP TIE-96 zeolite and the IE-96 zeolite modified by Ti addition) under most conditions for removing Pu, better than the zeolite under all conditions with respect to Cs selectivity, and far better under all conditions with respect to Sr selectivity. The Nb-doped TAM-5 yields Sr selectivity comparable to the TAM-5 with no niobium. For example, under equilibrium pH>12, the Nb-doped Se K d is approximately 10,000 mL/g.
TAM compositions can be prepared from a wide variety of Si and Ti reactants. Some dopants have been identified to have positive effects on selectivity of TAM compositions. Nb-doped TAM has been prepared using Nb, Ti, Si-containing hydrous metal oxides and sodium metasilicate as reactants and by substituting hydrated niobia (Nb 2 O 5 ) for PEN in the initial baseline method. Nb-doped TAM-5 with high Cs selectivity has been prepared in a period of 60 minutes under hydrothermal conditions at 200° C. Small amounts of Nb-doped TAM-5 form at 92° C. which would be a less expensive preparation than under hydrothermal conditions.
Further samples of TAM-5 and TAM-5 modified with niobium were synthesized for the purpose of performing detailed chemical and physical characterizations. The characterization data were used to support determination of the structure, identify differences in performance for radionuclide separations for different TAM-5 compositions, and to differentiate the TAM-5 materials from other silicotitanate structures. The samples and their preparation parameters are described in Table VIII:10-19, as follows (the molecular ratios are for the charged reactants and not the composition of the final product):
TABLE VIII
10-19
REACT
EX-
OR
SRD
AM-
SIZE
H 2 O/
NaOH/
Si/
Nb/
Time
Temp
XRD
c 0 ,
PLE
(GAL)
Ti
Ti
Ti
Ti
(hr)
(° C.)
a 0 , Å
Å
10
1
165
2.46
1.13
0
2
230
7.787
12.00
11
1
164
2.46
1.13
0.10
2
230
7.800
11.997
12
1
165
2.46
1.13
0.16
2
230
7.814
12.016
13
1
165
2.46
1.13
0.25
120
200
7.869
11.969
14
1
165
2.46
1.13
0.33
2
230
7.846
12.044
15
1
165
2.46
1.13
0.40
2
230
7.850
12.050
16
5
165
2.46
1.13
0.40
2
230
7.846
12.043
17
1
165
2.46
1.13
0.50
2
230
7.846
12.050
18
1
165
2.46
1.13
0.60
2
230
7.847
12.050
19
1
165
2.46
1.13
1.00
2
230
ND
ND
ND-not determined, material is not crystalline
With the exceptions as noted in Table VIII:10-19 all samples, Examples 10-19, were made in accordance with the procedure as described in Example IV:2 as earlier described.
Examples VIII:10-19 were subjected to elemental analysis with the ratio of elements as set forth in Table IX:10-19 below.
TABLE IX
10-19
EXAMPLE
Na
Si
Ti
Nb
10
0.87
0.57
1.0
0.0
11
1.03
0.67
1.0
0.11
12
1.03
0.67
1.0
0.17
13
1.02
0.69
1.0
0.24
14
1.09
0.67
1.0
0.35
15
1.10
0.83
1.0
0.38
16
1.09
0.69
1.0
0.42
17
1.18
0.68
1.0
0.51
18
1.27
0.69
1.0
0.62
19
1.65
0.86
1.0
1.04
Initial powder x-ray diffraction data on a Nb-doped/TAM-5 material like that of example 13 of Tables VIII and IX indicated that the crystalline material had approximate lattice constants of 7×7×12 Å, and further TEM results indicated that the material was tetragonal. The complete structure determination process for this Nb-doped TAM-5 material involved room temperature (25° C.) x-ray diffraction, between 2θ=15-80°, with a step size of 0.02° for a total of 3500 data points. The crystal structure of this material was established by the x-ray Rietveld refinement, using the starting model of a naturally occurring titanosilicate crystal in the tetragonal space group of P4 2 /mcm (Sokolova, E.V., Rastsvetaeva, R.K., Andrianov, V.I., Egorov-Tismenko, Yu. K., Men'shikov, Yu. P. Sov. Phys. Dokl. 1989, 34(7), 114.)
As with the model material, a Nb-doped TAM-5 material like that of example 15 of Tables VII and IX is a molecular sieve with titanium (and a percentage of niobium in disordered sites substituted for Ti) and silicon atoms as the framework atoms separated by bonding oxygen atoms. The resultant framework is negatively charged with an approximated empirical formula of (Si 2 NbTi 3 O14) −3 . One of the framework oxygen atoms is considered part of a hydroxide group (—OH) and is therefore an extra negative charge. The Ti/Nb atoms are octahedrally (six coordinate) bound to oxygen atoms, while the Si atoms are tetrahedrally (four coordinate) bound to oxygen atoms. Four Ti atoms are edge-bonded to each other, forming a cubic cluster in the “corners” of the cages (in the ab-plane); these cluster also form chains in the c-direction. In the ab-plane, the octahedra of the cluster chains are corner bonded to the Si tetrahedra through oxygen atom O (4) with a normal Si—O bond length of 1.657 (2) Å. There are four “cylinderical” cages formed per unit cell of this molecular sieve.
The non-framework components of this Nb-doped TAM-5 material (example 15) include water molecules and charge balancing cations. The water molecules are not charged but do occupy space in the sieve cage. The cations (with positive charges) have three sites, two in the cage and one in the walls, (above the silicon atom). These cations are responsible for charge balancing the framework.
All Example VIII samples, except examples 12 and 17, were examined by a transmission electron microscope (TEM) and the results observed are given in Table X:10-19, below.
TABLE X
10-19
Estimated
Mean Particle
Tetragonal
Size of
Na—Ti-
(Nb, Ti)-
Tetragonal
Estimated
silicate
(Nb, Ti)-
silicate
Na—Ti-silicate
Volume
Example
“cuboids”
oxide “rods”
“platelets”
Other Phases
crystals (μm)
Fraction
10
100%
—
—
—
0.02
1.0
11
100%
—
—
—
0.02
1.0
13
>98%
<1%
<1%
Ti oxide
0.02; 0.15*
0.98
lenticular particles
<<1%
Si—O—Ti—Nb
platelets
<<1%
14
>98%
1-2%
<1%
—
0.2
0.98
15
>98%
−1%
<1%
—
0.2
0.98
16
˜95%
˜5%
—
—
0.2
0.95
18
˜85%
10-15%
˜2%
Si—O—Ti—Nb:
0.4-0.5
0.85
1%
19
2-3%
20-25%
20-25%
Ti—Nb-silicate + Na
0.35
0.025
amorphous: 50-60%
Si—Ti—Nb—Na—O: <1%
Na—Nb-
silicate + Ti: <1%
*Represents a bimodal distribution of crystal sizes
BET surface area, pore volume, and pore diameter measurements were conducted on examples 10-19 using a Quantachrome corporation Autosorb 5 Gas Sorption System. Quantachrome Corporation is located in Syosset, N.Y.
Surface area was determined by the multi-point Brunauer-Emmett-Teller (BET) procedure. Total pore volume and pore diameter was derived from the amount of vapor absorbed at a relative pressure close to unity, assuming that the pores are filled with liquid adsorbate. The results obtained are given in Table XI:10-19, below.
TABLE XI
10-19
Surface Area
Pore Volume
Pore Diameter
Example
(m 2 /g)
(cm 3 /g)
(Å)
10
111.7
0.932
333.5
11
65.7
0.587
357.7
12
38.3
0.431
450.1
13
29.4
0.341
414.8
14
31.5
0.265
336.4
15
39.0
0.253
260.1
16
30.5
0.236
309.3
17
34.8
0.167
192.1
18
36.2
0.252
279.3
19
80.7
0.572
283.4
Thermogravimetric analyses (TGA) of crystalline silico-titanates of examples 10-19 were conducted using a TA Instruments Model 2000 controller coupled to a Model TA 951 Thermogravimetric Analyzer (TGA) module. TA Instruments, Inc. is located in New Castle, Del. Differential scanning calorimetry (DSC) measurements of CSTs were conducted on the TAM-5 materials of examples 10-19 using a TA Instruments Model 2000 controller coupled to a Model 910 Pressure Differential Scanning Calorimeter (DSC) Module. The results, expressed as % water loss, are recorded in Table XII:10-19 below.
Transition onset temperature (C), heat of transition (Joules/gram), and transition temperature as the exotherm was calculated for each sample, with the results are reported in Table XII:10-19 below.
TABLE XII
10-19
Transition
Transition
Heat of
Temperature
Onset
Transition
(° C.)
Temperature
(Joules/gm)
(Exotherm)
% Water
Example
(° C.) (DSC)
(DSC)
(DCS)
Loss (TGA)
10
206.2
56.8
226.7
4.865
11
197.4
98.9
225.9
5.359
12
205.0
83.0
229.7
5.490
13
208.5
84.0
237.8
6.008
14
206.8
89.5
226.2
5.860
15
202.8
81.3
228.7
5.926
16
210.3
81.7
231.6
5.287
17
204.7
95.0
231.0
5.450
18
202.5
72.6
226.5
5.389
19
195.7
36.8
244.0
3.799
Cesium distribution coefficients (K d ) values were measured for the crystalline silicotitanate powders TAM-5 and TAM-5 modified with a niobium dopant of example 10-19 and are shown in the following Table XIII:10-19. These cesium ion-exchange experiments were conducted using the following procedure.
One hundred milligrams (mg) of as received crystalline silico-titanate powder was weighted into a 20 milliliter (mL) polyethylene terephthalate (PET) plastic scintillation vial. Ten milliliters of waste simulant was added to the vial. The waste simulant was an aqueous solution containing 5.7 M NaNO 3 and 0.6 M NaOH, and a 100 mg/L concentration of cesium chloride solution. The vial was capped, and placed on a wrist action shaker. Samples were agitated for 18-24 hours, removed from the shaker, and the powder material permitted to settle. The supernate was vacuum filtered with 0.2 micron membrane filters. The supernate was then diluted 10:1 prior to cesium analysis by flame atomic absorption spectroscopy. K d 's were calculated using the following formula: K d ( ml / gm ) = Cs Cl
where:
Cs=concentration of cesium on the exchanger ( g Cs g solid ) ,
and
Cl=concentration of cesium in the liquid ( g Cs ml liquid
Example
Cs K d , ml/g
10
40
11
120
12
490
13
790
14
890
15
950
16
1010
17
810
18
840
19
4
These newer TAM-5 and Nb-doped TAM-5 materials were studied in solutions of 100 ppm Cs and 5.7 M Na at different pHs (though spanning the range of 2.5 M OH − to 1.0 M H + (for their selectivity performance in terms of cesium distribution coefficiency, K d . The trends observed are illustrated in FIG. 14 .
Further, the effect of differing acid concentrations over time on the cesium distribution coefficient of the TAM-5 and Nb-doped TAM-5 materials was studied in nitric acid solutions of molarity between 1 and 6 after 18 hours and 5 days. The cesium distribution coefficient remained essentially steady at a K d value of 800 over the molarity values and time range studied. The TAM-5 materials were further studied for stablity in a simulated waste solution containing 1.3 M free OH − over a 90 day period. The cesium distribution coefficient observed for the TAM-5 material over such time span remained essentially steady, i.e., within a K d range of about 140-160. Further, the performance of a TAM-5 material for cesium selectivity was studied and solutions containing various concentrations of potassium compared to cesium and solutions containing various amounts of sodium compared to cesium. In solutions with K/Cs ratios ranging from 100 to over 18,000, the K d values of TAM-5 materials studied decreased only by a factor of two. In sodium solutions, TAM-5 materials exhibited higher K d cesium selectivity at sodium concentrations of 0.1 to 10 molar than did CS-100, IE-96 or BIB-DJ absorbance.
Samples of CST TAM-5 materials were tested for cesium ion-exchange capacity. The samples included TAM-5 with Nb/Ti ratios in the range of 0-1. When prepared with repeated washings by 10% acetic acid followed by cesium hydroxide, the cesium capacities ranged from 22-24% Cs by weight. When prepared with repeated washings of cesium chloride, the capacities ranged from 15-21%.
Samples of TAM-5 material were exposed to radiation doses of 10 7 , 10 8 , and 10 9 rads (Si), corresponding to 7.0, 70.2, and 698 hours of exposure respectively, from a Co-60 source. The test temperature was maintained at 25° C. Samples were tested as follows: dry powders, powders in Hanford Tank 101-AW simulant solution, Cs-loaded material in 101-AW simulant solution, Cs- and Sr-loaded material in 101-AW simulant solution, Cs-loaded material in 2M HNO 3 , and amorphous hydrous titanium oxide (HTO) material. Multiple samples were tested for each category of tests. The amorphous hydrous titanium oxide material was tested as a control as previous literature data on its radiation stability are available.
Stability was determined by examining the Cs (or Sr) distribution coefficients and the XRD patterns of the materials both before and after exposure to the radiation fields. In comparing the distribution coefficients before and after exposure to the radiation field, the distribution coefficients were within experiment measurement error of the cesium concentration as measured by atomic absorption spectroscopy. Specifically, the distribution coefficients of the TAM-5 dry powders, the TAM-5 materials in the 101-AW simulant, and the samples fully loaded with Cs generally showed less than 5% variation in comparing performance before and after radiation exposure. No significant effect on performance was noted, even after exposure to 10 9 rads (Si).
TAM Compositions as Catalyst Supports
As disclosed above, certain TAM compositions, as well as CT TP2 (Type 2 CT) disclosed in application Ser. No. 07/751,003, filed Aug. 28, 1991, comprise excellent precursors and supports for sulfided catalysts (e.g. Ni—Mo). Such catalysts are used in the hydrogenation of organic components (e.g. heavy crude oils), direct liquefaction of coal, and hydrodesulfurization (HDS) of organic components (e.g. heavy crude oils).
Preparations of these catalyst supports initially involve preparation of TAM-1 by any of the many methods disclosed herein; Type 2 CT is prepared as disclosed in U.S. Pat. No. 5,177,045. TAM-1 and Type 2 CT are first ion exchanged with sulfuric acid to remove the sodium cation, removed from solutions by filtration and washed with acetone. The compositions are then reslurried in an aqueous solution containing the desired amount of ammonium heptamolybdate and the pH is adjusted to 4 by addition of sulfuric acid. The slurry is then filtered and rinsed with acetone and either reslurried in deionized distilled water or partially dried. If reslurried, the pH is adjusted to 6 by addition of ammonium hydroxide; nickel nitrate is then added. The pH is maintained at 6 by addition of acid or ammonium hydroxide. The slurry is filtered and rinsed with acetone. If not reslurried, nickel nitrate is loaded onto the catalyst by the incipient wetness technique.
The catalysts are then dried for up to 12 hours at 65° C. in a vacuum oven. After drying, the catalysts are sulfided with hydrogen sulfide at 425° C. Alternatively, the catalysts may be calcined at 500° C. for 4 hours prior to sulfiding.
For testing purposes, 10 mg of the prepared catalysts (i.e. sulfided Ni—Mo TAM-1, and Type 2 CT) were sized to less than 100 mesh, slurried in 1 gram of hexadecane and 100 mg of pryrene, and placed in a batch reactor. The reactor was pressured to 1430 psig hydrogen at room temperature. The reactors themselves were then placed in a container and maintained at 300° C. for a period of 10 minutes.
Table 14 is a comparison of catalytic activity for hydrogenating pyrene to dihydropyrene using sulfided Ni—Mo supported on Type 2 CT, TAM-1, amd hydrous silicon titanium oxide and hydrous silicon titanium oxide, as well as the commercial catalysts, Shell 324 and Amocat 1C.
TABLE 14
COMPARISON OF CATALYSTS ACTIVITIES FOR HYDROGENATION OF
PYRENE (pyr) AND HYDRODESULFURIZATION (HDS) OF DIBENZOTHIOPHENE
Catalyst
Form
No, % a
Ni, % a
SA, m 2 /g c
K pyr c
K pyr f
η
K HCS a
K KDS f
BP/CHB
Shell 324
1/32″ Extrud.
13.2
2.7
152
0.041
0.31
0.24
0.016
0.121
1/6
Shell 324
−100 Mesh
13.2
2.7
152
0.120
0.91
0.72
ND
ND
ND
Shell 324
−200 Mesh
13.2
2.7
152
0.158
1.20
0.92
0.028
0.158
1.9
Amocat 1C
1/16″ Extrud.
10.7
2.4
177
0.038
0.36
0.24
ND
ND
ND
Amocat 1C
−100 Mesh
10.7
2.4
177
0.059
0.55
0.38
ND
ND
ND
Amocat 1C
−200 Mesh
10.7
2.4
177
0.155
1.45
1.0
ND
ND
ND
NiHO-Type 2 Ct
−100
5.35
1.76
160 e
0 ×
1.22
0.8 d
ND
ND
ND
(Batch #50)
Mesh/Sulfided @
0.065
425° C.
TAM-1, Si/Ti = 1.1
−100
2.85
0.97
160 e
0.027
0.94
ND
0.0085
0.30
11.9
Mesh/calcined @
500° C./sulfided @
425° C.
TAM-1, Si/Ti = 1.1
−100
2.85
0.97
160 e
0.024
0.83
ND
0.0073
0.26
3.16
Mesh/sulfided @
425° C.
yyNiMe—Na 0.3 Ti b
−100 Mesh
11.2
3.7
130
0.186
1.66
ND
0.0302
0.0302
2.8
NiMo—Na 0.3 TiSi 0.25 b
−100 Mesh
8.7
3.0
166
0.268
3.08
ND
0.0132
0.985
2.8
a Composition and surface areas of as-received Amocat 1C and Shell 324. Composition of HTO and CT-based Catalysts after calcination @ 500° C.
b These are the latest and best of the HTO-Based NiHO Catalysts.
c Prior to ion exchange and after degassing at 150° C. for 12 hous.
η = Effectiveness Factor; Effective Diffusivities based on pyrene for Shell 324 and Amocat 1C are 6.5(10) −12 and 3.2(10) −11 m 2 /n. The efectiveness factors were calculated assuming a pseudo first order rate equation and spherical particles.
d Calculated based on an estimate of the effective diffusivity of pyrene.
ND = not determined.
BP/CHB = Moles of biphenyl divided by the moles of cyclohexyl benzene. A high ratio indicates efficient utilization of hydrogen.
e Rate constant with units of sec −1 . gram catalyst −1 .
f /rate constant with units of sec −1 . gram No −1 .
The data illustrate that sulfided Ni—Mo supported on Type 2 CT, and TAM-1 have comparable activity on an active metal basis as the commercial catalysts and the Ni—Mo—Na 0.5 Ti amorphous catalyst, but the sulfided Ni—Mo Na 0.5 TiSi 0.25 amorphous catalyst has a much higher activity. For the amorphous Ti catalysts and Type 2 CT the majority (>98%) of the sodium was removed prior to loading Mo and Ni by using O.lN HCl. TAM-1 had a sodium level of 2.27% prior to the loading even though H + /Na + ion exchange had been performed. Initial sodium levels of TAM-1 varied from 8% to 12%. Aqueous mixtures of approximately 10% solids were used when preparing the catalysts instead of the 0.1% solids used in determining ion exchange capacity.
Table 14 also illustrates the resistance to pore diffusion exhibited by the commercial catalysts.
Table 14 also indicates hydrodesulfurization (HDS) of the TAM catalysts on a per gram basis to be considerably less than that of Shell 324. This is probably due to low Mo loading; the activity of the TAM catalysts on a per gram of Mo basis is greater than Shell 324. Also, the ratio of biphenyl to cyclohexyl benzene is greater for the TAM catalysts than Shell 324 or the amorphous catalysts. The ratio for the TAM catalysts also depends on the method of preparation. The TAM compositions are novel compositions which show high hydrogenation activities when used as precursors for sulfided Ni—Mo catalysts.
The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.
Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results.
Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references cited above are hereby incorporated by reference.
|
Noval silico-titanates and the methods of making and using the said titanates are disclosed. Nb-doped silico-titanates are particularly useful for selectively removing cesuim from radioactive wastes.
| 2
|
This is a division of application Ser. No. 031,552, filed Mar. 30, 1987, now abandoned.
FIELD OF INVENTION
This invention relates to a trunnion housing and a trunnion shaft and more particularly to a steam tilting kettle supported by a single trunnion assembly.
BACKGROUND TO THE INVENTION
Steam kettles are being used on a commercial basis to heat relatively large quantities of foods such as soup, sauces or the like. Such kettles or vessels have an opening at the top thereof for receiving such foods and are heated in the kettle to the appropriate cooking temperature. Once the food is cooked the titling kettle is adapted to be swivelled about a pivot point so as to pour out the contents therein into an appropriate container. Such tilting kettle or vessels are adapted to swivel about trunnion assemblies which include a trunnion shaft and trunnion housing.
Canadian Pat. No. 1,154,272 relates to a vapour jacket cooking vessel having tubular evaporators with a closed end and an open end where the open end is affixed to the vapour jacket so that the working fluid flows into and floods the evaporator and functions as the working fluid therein.
Furthermore, Canadian Pat. No. 694,947 relates to an elevating mechanism used in association with the kettle.
U.S. Pat. No. 1,993,779 discloses a heat transfer medium passing through two trunnions.
U.S. Pat. No. 2,411,006 discloses two trunnions each of which is longitudinally bored to form a steam conduit leading into the chamber and a valve which is provided to control the delivery thereto.
The steam jacketed tilting kettles heretofore have been supported and adapted for rotation about an axis passing through two trunnions connected at oposite sides of the kettle. The use of two trunnions for steam jacketed tilting kettles presents relatively complicated structure as well as causing difficulties in lining up the two trunnions (located in bearings) after welding.
It is an object of this invention to construct an efficient steam tilting kettle and particularly a steam tilting kettle which is supported for rotation about a single trunnion assembly.
FEATURES OF THE INVENTION
The broadest aspect of this invention relates to:
a steam kettle adapted to rotate about a horizontal axis of rotation between a vertically upright position and a tilted position comprising; a support; a kettle having an open top and presenting an inner and outer shell defining a heat exchange chamber there between; said outer shell having a steam inlet and a steam condensate outlet, both said inlet and outlet communicating with said heat exchange chamber; a stationary trunnion housing connected to said support, said trunnion housing including a cylindrical hole extending through said housing along said horizontal axis; a trunnion shaft received within said cylindrical hole of said trunnion housing and arrange for rotation about said horizontal axis, said trunnion shaft connected at one axial end of said shaft to said outer shell of said kettle so as to cover said steam inlet and steam condensate outlet, whereby said kettle is solely supported by said trunnion shaft adapted for rotation about said horizontal axis within said cylindrical hole of said stationary trunnion housing between said vertical upright position and said tilted position; said trunnion housing including a first and second aperture for communicating steam and steam condensate to said cylindrical hole; said trunnion shaft including, a first conduit therein and arranged for communicating with said steam inlet and said first aperture so as to direct steam into said heat exchange chamber when said kettle is in said vertically upright position, and to substantially prevent the communication of steam into said heat exchange chamber in said tilted position, a second conduit therein and arranged for communicating with said steam condensate outlet and said second aperture so as to exhaust said steam condensate from said heat exchange chamber through said steam condensate outlet when said kettle is in said vertically upright position, and to substantially prevent communication of steam condensate from said heat exchange chamber through said steam condensate outlet when said kettle is in said tilted position; securing structure adapted to receive releasable retaining structure for releasably retaining said trunnion shaft with said cylindrical hole of said trunnion housing.
DRAWINGS
These and other objects and features will now be described in association with the following drawings:
FIG. 1 is a front elevational view of said steam tilting kettle.
FIG. 2 is a side elevational view of said kettle.
FIG. 3 is a partial cross-sectional view of said trunnion shaft.
FIG. 4 is a partial cross-sectional view of said trunnion housing.
FIG. 5 is a top plan view of said trunnion housing.
FIG. 6 is a cross-sectional view of said trunnion assembly.
DESCRIPTION OF THE INVENTION
Like parts have been given identical numbers throughout the figures.
FIG. 1 illustrates the steam kettle sometimes referred to as a steam jacketed tilting kettle, which consists of inner shell 4 and outer shell 6 which is generally made of stainless steel. Inner shell 4 and outer shell 6 define a heat exchange chamber 8 therebetween.
The steam kettle 2 is supported by single trunnion assembly 50 which is connected to an upright console 12 which is connected at the bottom end thereof to a horizontal base 14.
The steam kettle 2 is adopted to receive food substance though the open top end 10 thereof. The food substance is cooked in the kettle 2 by transfer of heat energy from the steam in the heat exchange chamber which shall be more fully described herein.
Once the food substance is cooked such substance may be poured out of the kettle 2 by means of grasping the tilt handle 16 and pulling forward causing the kettle 2 to pivot about the single trunnion assembly 50 to a position marked by the phantom lines in FIG. 2, thereby causing the food substance to pour out over the lip 18 of kettle 2.
Once the food substance is poured out of kettle 2, the inside of kettle 2 may be cleaned by means of introducing hot or cold water through the swivel nozzle 20 by activation of hot or cold water valve 22 and 24 respectively.
By utilizing a single trunnion assembly 50, as shall be more fully described herein, one may construct a steam kettle having a relatively simplified construction, which is aesthetically pleasing to the eye, as well as producing a kettle which is relatively easier to clean thereunder without the obstruction of legs or the like.
The trunnion assembly 50 comprises generally a trunnion shaft 80 as illustrated in FIG. 3 and 4 and trunnion housing 100 as illustrated in FIGS. 5 and 6.
The trunnion shaft 80 is fabricated from steel and is adapted to be connected to the outer shell 6 of kettle 2 at one end 52 thereof by means of welding and shall be described herein, or by other suitable means.
The trunnion shaft 80 is adapted for rotation about an axis of rotation 40. Trunnion shaft 80 presents a first conduit 54 for introducing steam through said shaft 50 and out through one end 52 of such shaft 50. The trunnion shaft 80 also includes a second conduit 56 for exhausting steam condensate from said one end 52 of said shaft 50 through such shaft 80 and out therefrom.
As best illustrated in FIG. 4, first conduit 54 and second conduit 56 are disposed relatively parallel to one another and to the axis of rotation 40.
The first conduit 54 generally consists of a first conduit inlet 58 presented in the cylindrical surface 60 of the trunnion shaft 80. Such inlet 58 merges with a first cylindrical hole 62 having a first axis 64 disposed in said shaft 80 which is generally parallel to the axis of rotation 40.
The first cylindrical hole 62 is producted by drilling a hole from one end 52 of the shaft 80 to a region near the other end of the shaft 65. This produces a conduit outlet 66 at the one end 52 of shaft 80. The first conduit inlet 58 is produced by drilling a hole through surface 60 so as to intersect and merge with the first cylindrical hole 62.
First conduit 54 is adapted to introduce steam through the first conduit inlet 58, first cylindrical hole 62 and out the first conduit outlet 66.
The first conduit outlet 66 also presents an enlarged opening 68 which is adapted to receive a steam inlet tube 138 as shall be described more fully herein.
The shaft 80 also includes the second conduit 56 which generally consists of a second conduit outlet 70 presented in the cylindrical surface 60 of shaft 80. Such outlet 70 merges with a second cylindrical hole 72 having a second axis 74 disposed of in the shaft 80 which is generally parallel to the axis of rotation 40.
The second cylindrical hole 72 is produced by drilling a hole from the one end 52 of shaft 80 to a region between ends 52 and 65 of shaft 80. This produces a second conduit inlet 76 at the one end 52 of shaft 80. The second conduit outlet 70 is produced by drilling a hole through the surface 60 so as to intersect, merge and communicate with the second cylindrical hole 72.
Second conduit 56 is adapted to exhaust or vent steam condensate from said one end 52 of shaft 80 through the second conduit inlet 76, second cylindrical hold 72, and second conduit outlet 70.
As can be best seen from FIG. 4, first conduit inlet 58 and second conduit 70 are axially spaced along the shaft surface 60 and disposed 180 degrees from each other.
The one end 52 of shaft 80 is disposed at an acute angle of 75 degrees from the axis of rotation 40 so as to assist in welding said one end 52 to the circular girth of outer shell 6 of kettle 2.
First cylindrical hole 62 is larger in diameter than second cylindrical hole 72.
FIGS. 5 and 6 generally illustrate trunnion housing 100 which comprises a cylindrical hole 102 adapted to receive trunnion shaft 80 for relative rotation therebetween about an axis of rotation 40. Trunnion shaft 80 includes an annular groove 67 in the region of the other end 65 which is adapted to receive a "C" clip (not shown) so as to removably fixedly retain trunnion shaft 80 within hole 102.
Trunnion housing 100 includes a first aperture 104 adapted to communication with hole 102 and first conduit opening 58 to direct steam therethrough; and a second aperture 106 adapted to communicate with hole 102 and second conduit outlet 70 so as to exhaust steam condensate therefrom.
First aperture 104 includes threads 108 for connecting to a steam pipe and valve (not shown) for introducing steam under pressure. Second aperture 106 includes threads 110 for connecting to a steam condensate exhaust pipe and valve (not shown).
Trunnion housing 100 also includes holes 112 which are adapted to receive bolts for anchoring the trunnion housing 100 to the interior of support or console 12 so as to present the axis of rotation 40 in a horizontal position.
Trunnion housing 100 also includes enlarged diametral ends 114 adapted to retain bushings 115 for rotational contact with the trunnion shaft 80 so as to minimize the frictional drag therebetween.
Hole 102 of trunnion housing 100 also includes three spaced angular groves 116 adapted to receive and retain O-rings for sealing contact with shaft 80 thereby minimizing any leakage of steam between the first and second conduits 54 and 56 respectively as well as to the outside environment. Furthermore the trunnion shaft 80 is supported by bushings 115 while the O-rings are adapted to perform a sealing function. The trunnion shaft 80 is not supported by the O-rings.
As can be seen from FIG. 6 one end 52 of trunnion shaft 80 is connected to outer shell 6 by means of welding. A shell reinforcement plate 122 is also welded to the outer shell 6 at 124 as well as the one end 52 of trunnion shaft 80 at 126. Furthermore, a body reinforcement plate 125 is welded to outer shell 6 at 128 and to trunnion shaft 80. Shell reinforcement plate 122 and body reinforcement plate 125 is utilized to rigidify the connection of trunnion shaft 80 to outer shell 6.
Outer shell 6 and shell reinforcement plate 122 present holes 130 and 132 respectively which communicate with first conduit outlet 66 and present holes 134 and 136 respectively which communicate with second conduit inlet 76.
Enlarged opening 68 is adapted to receive steam inlet tube 138 as illustrated in FIG. 6. Steam inlet tube 138 is adapted to have a tight fit between the inside diameter of first conduit outlet 66 and the outside diameter of steam inlet tube 138. The steam inlet tube 138 is welded to trunnion shaft 80 as illustrated in FIG. 6.
Heat exchange chamber 8 presents a deflector plate 140 which is welded to the inside surface of outer shell 6 in the region of first conduit outlet 66 so as to deflect steam downwardly into the heat exchange chamber 8.
A condensate return tube 142 is also provided which is connected to the inside surface of outer shell 6 and is disposed between second conduit inlet 76 and the bottom of kettle 2. The condensate return tube 142 is adapted to permit the steam condensate which tends to fall to the bottom of the kettle 2 to be exhausted through condensate return tube 142, holes 134, 136, second conduit inlet 76, second cylindrical hole 56, and second conduit outlet 70 and second aperture 104 and out therethrough to suitable piping which is not shown.
The operation of the tilting kettle shall now be described by reference to FIG. 6.
The tilting kettle 2 is filled with food stuff and may be filled with hot or cold water as required by turning hot and cold valves 22 and 24. The steam control valve 13 is then turned so as to introduce steam into the first aperture 104, first conduit inlet 58, first cylindrical hole 62, first conduit outlet 66, and heat exchange chamber 8 so as to heat the inner wall of shell 4 with steam. Heat energy is then transferred to the food to heat same, and the steam condensate is exhausted since first aperture 104 and first conduit 54 line up when the kettle 2 is in the vertical or operative position, and second conduit 56 and second aperture 106 line up when kettle 2 is in the vertical or operative position.
Once the food is cooked to the desired temperature such food may then be removed as earlier described by tilting handle 16 forward and pouring out the food over lip 18. When the kettle 2 is displaced from the vertical or operative position, to a tilted or inoperative position, first aperture 104 and first conduit 54, as well as second aperture 106 and second conduit 56 no longer register or communicate with one another and any steam condensate flow would be drastically reduced.
Steam control valve 13 may be turned off once the food is cooked before the kettle is tilted.
A second kettle 2 may be attached to the right hand side of console 12 by a single trunnion assembly 50 so as to present twin tilting kettles.
The kettle 2 operates efficiently between 5 and 50 pounds per square inch of pressure while a 20 pound per square inch operating pressure is recommended. A pressure reducing valve may be installed on the steam supply line if the maximum 50 pounds per square inch is exceeded.
Although the preferred embodiment as well as the operation and use have been specifically described in relation to the drawings, it shall be understood that variations in the preferred embodiment could easily be achieved by a man skilled in the art without departing from the spirit of the invention. Accordingly, the invention should not be understood to be limited to the exact form revealed by the drawings.
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A steam kettle adapted to rotate about a horizontal axis of rotation between a vertically upright position and a tilted position comprising a support; a kettle having an open top; a stationary trunnion housing connected to said support; a trunnion shaft received within said trunnion housing and arranged for rotation about a horizontal axis whereby said kettle is solely supported by said trunnion shaft adapted for rotation about said horizontal axis between said vertical upright position and said tilted position; and securing structure adapted to receive releasable retaining structure for releasably retaining said trunnion shaft with said cylindrical hole of said trunnion housing.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to structural supports, and particularly to a system for selectively enhancing the support configuration of cantilever beams on jack-up drilling units or the like.
2. Description of the Relevant Art
A major limitation with oil well drilling or work over activities involving jack-up units utilizing a platform jacket and cantilever beam is the reduced drilling load available, due to the outreach position of said cantilever beams.
In such systems, the drill-floor that carries the drilling derrick is typically supported by 2 independent beams via a substructure that forms the cantilever assembly. The drill-floor skids transversely, to reach the drilling template ports, and as a result of this movement, the drilling load is applied unequally on the two cantilever beams. Thus, maximum outreach and offset of the drill-floor are dictated by the allowable load limits of the beams.
To assist the operator, a chart specific to every vessel indicates the position of the floor in relation with the allowable drilling load, and on average, the maximum drilling load is achievable over a limited portion of the drilling envelope. Generally, when drilling over a platform jacket the cantilever works at a far outreach only where the drilling load is reduced.
Accordingly, the reduced drilling loads impose limitations on operations, the greater extent maximum drilling load being achievable only within the pre-established drilling envelope. Self elevating platforms (jack-ups) which have good load chart capabilities surely are preferred by operators in a competitive market.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a retractable auxiliary support to the cantilever beams of self elevating units such as jack-up units or the like.
Another object of the present invention is to provide additional supports mounted on the transom along the cantilever beam path so as to sustain positive reaction, provide additional support, and thereby improve the cantilever rated load charts.
Still another object of the present invention is to provide selectively deployable supports to an approximate reported length of approximately one third of the cantilever beam working envelope, a length to which generally would not be practical for a self elevating unit to have permanently installed, as it would reduce the ability to stand close by a platform jacket installation.
To achieve the above-mentioned objects a retractable or portable structure is secured on the transom of the vessel. Sound mechanical interface connections are provided to transmit the efforts of the portable structure onto the bottom and support bulkhead of the jack-up vessel. The horizontal efforts are transposed to the vessel at the upper end of the cantilever beam support bulkhead, and at the lower end to the inner bottom structure. The structure is retractable or portable for two reasons; first the auxiliary structures need to be out of the way for jacking operation where if deployed they would interfere with the jacket envelope, secondly if they are not required for a drilling program the associated added weight can be removed without any negative impact on the payload of the vessel.
By the present invention, the new reaction added to the cantilever support arrangement has a primary purpose of increasing the rated capacity of the cantilever beams on the farther outreaches of the drilling envelope. The rating is improved by reducing the overhanging extent of the beams, where the bending effort of the cantilever beam is reduced by the same ratio.
The auxiliary structure is equipped with a low friction reaction pad to interact with the cantilever beam and transmit purely the vertical reaction. The structure can be designed to withstand, totally or partially, the reaction load at that point, depending of the requirement. The total load reaction is achieved by engineering the structure, considering no load sharing with the transom reaction point.
Partial load reaction is obtained by designing the auxiliary structure to share the cantilever beam loading once a certain level of deflection is reached. Partial reaction can be computed for any given support arrangement, where the relation between deflection and load is proportional.
From the load rating gain, the benefits of the invention become useful in many aspects. This gain gives the ability to carry the full drill string load (set back load) throughout the drilling envelope, with adequate hook load in reserve. This gain can also allow the conductor tensioning to be achieved from the cantilever beam itself rather than from the transom of the vessel which is the common traditional method.
When the tensioning is provided from the cantilever beams the drilling operation for exploration becomes more flexible because the conductor tensioning is possible along the entire length of the drilling envelope. In addition, when exploration drilling is possible further away from the transom, more valuable deck space is made available because the cantilever leaves more of the main deck exposed.
The above and further objects, details and advantages or the present invention will become apparent from the following description of preferred embodiments thereof, when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of the self elevating drilling unit or jack-up vessel alongside a platform ready to elevate into working position for a drilling program over the jacket.
FIG. 2 is an elevation view of the self elevating drilling unit or jack-up vessel elevated next to the platform jacket ready to deploy its cantilever beam and drill floor above the drilling template.
FIG. 3 is an elevation view of the self elevating drilling unit deployed over the platform jacket ready to drill.
FIG. 4 is a plan view of the self elevating drilling unit at the drilling template elevation with projected outline of cantilever and drill floor shown.
FIG. 5A shows sample load charts anticipated rating in relation with the drilling envelope, before implementation of the present invention.
FIG. 5B shows sample load charts anticipated rating in relation with the drilling envelope, after implementation of the present invention.
FIG. 6 is an elevation view that shows the self elevating unit or jack-up vessel on an exploration well scenario at an open location.
FIG. 7 shows a section view of the cantilever beam showing more details on the conductor tensioning method for exploration wells.
FIG. 8A illustrates a close, up, side view of the reaction frame of the present invention as pivotally attached to the stern of a vessel via mounting bracket, supporting a deployed cantilever.
FIG. 8B is an end view of the reaction frame of FIG. 8A .
FIG. 8C is a top view of the reaction frame of FIG. 8A .
FIG. 8D is a bottom view of the reaction frame of FIG. 8A .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiment of the present invention, contemplating a selectively deployable (i.e., retractable) reaction frame for self-elevating platforms utilizing cantilever beams, is described below with reference to the Figures. The utilization and deployment process of the present invention, as utilized in conjunction with a drilling unit, is also illustrated and discussed in detail, herein.
Referring to FIGS. 1 and 2 , a self elevating drilling unit comprising, for example, a jack up vessel 1 (also known as a jack up rig) is positioned 21 (for example, 5-10 feet, with the distance varying depending upon operator skills, soil, the vessel deployed, etc) so as to be situated adjacent 22 to a platform jacket 4 , then elevated 20 to working position 23 . First 7 and second 7 ′ reaction frames associated with the stern of the vessel are shown in their retracted 24 position, said frames mounted at the transom 11 of the jack up vessel 1 .
As shown, in the retracted position 24 , the reaction length of each of the frames is pivoted so that the length of each frame is situated adjacent to the transom, providing a storage position requiring minimal space.
A minimum distance “D” is kept between the jack up vessel 1 and the platform 4 , this proximity is required for the cantilever and drill floor to reach out an adequate distance to the drilling template 6 , once the platform is elevated above the platform deck 5 . As shown, the reaction frames 7 , 7 ′, being situated in their retracted position, allows the jack up vessel 1 to be positioned within the minimum distance “D” required.
Continuing with FIG. 2 , the jack up vessel 1 is shown in its working position 23 elevated above the platform deck 5 . The retractable stern reaction frames 7 , 7 ′ remain in their stowed position, and thus do not support the cantilever at this point.
The cantilever 15 , formed by first 2 and second 2 ′ longitudinally aligned beams, supporting drill floor 3 are shown stowed, ready to be deployed, and the broken lines show the outline of the cantilever 15 and drill floor 3 at working position where the arrow 25 shown within indicates the deployment movement direction.
In this traditional scenario, (i.e., without the added support of the reaction frames 7 , 7 ′ of present invention), the cantilever beams 2 , 2 ′ transmit the load to the jack up vessel 1 , predominantly at points R 1 and R 2 . R 1 has a hold down H/D effort where the cantilever beam is pushing upward under load. R 2 has a push up effort where the cantilever beams are bearing down under load. Accordingly, R 1 & R 2 generates a force couple that counteracts the overturning moment of the cantilever beam 2 , 2 ′.
Continuing with FIGS. 3 and 4 , cantilever 15 and the drill floor 3 , elevated above the platform deck 5 , may now be deployed 25 into their extended, working position (for example, cantilever extending 20-25 feet above platform), situated in spaced 28 relation above the drilling template 6 . The reaction frames 7 , 7 ′ are pivoted 26 , 26 ′ from their stored position, with their length adjacent to the transom, to their deployed 27 , 27 ′ position, wherein their length is generally transverse the transom, so as to extend added support surfaces 29 , 29 ′, to the cantilever beams 2 , 2 ′ at support points R 3 and R 3 ′, respectively.
Those support points R 3 , R 3 ′ project significantly outward of the transom, ideally, for example, approximately one third 35 of the cantilever beam working envelope 34 , so as to increase the distance between the reaction points, as well as to generate a more effective force couple, so as to sustain the overturning moment of the cantilever beam 2 . As earlier indicated, partial load reaction can be obtained by designing the reaction frames (i.e., auxiliary structure) to share the cantilever beam loading, once a certain, level of deflection has being reached. Partial reaction can be computed for any given support arrangement, where the relation between deflection and load is proportional.
The present invention thereby provides an innovative support arrangement unlike any prior art on a self elevating drilling unit, and defines the basics of the present invention.
FIG. 4 shows a plan view at the main deck level of the jack up vessel 1 , the drilling template 6 of the platform 4 ( FIG. 3 ) is also shown as an indication, and the cantilever beams 2 , 2 ′ and drill floor 3 outlines are also shown. The drilling envelope 8 sets forth the boundaries wherein the well center 30 can be positioned. The illustration also shows the drill floor 3 skidded to port side and the cantilever 15 to its maximum outreach, overlaid over the drilling template 6 .
The drilling template 6 comprises many ports for well to be drilled through, the shaded ports show the boundary where the cantilever 15 can drill with full rated load under conventional support arrangement (without the use of the reaction frame of the present invention), beyond this limit the rating is reduced.
Once again, an important feature of the present invention is that the reaction frames 7 , 7 ′ are stowable into a compact storage position allowing the vessel to be positioned within the minimum distance D (for example, 5-10 feet, depending upon soil conditions and operator skills) and be raised to the appropriate position for extending of the cantilever above the drilling template 6 . (as shown in the above discussed FIGS. 1 and 2 ).
Further, as shown in FIGS. 3 and 4 , the reaction frames 7 , 7 ′, once in their deployed, extended position to support the cantilever, said reaction frames extend beyond the minimum distance D for lowering the vessel (as said deployed frames would collide with the underlying platform if the vessel is lowered below the platform level), and therefore said reaction frames must be re-stowed (as shown via pivoting 26 , 26 ′, at the first end of each frame, so that each frame is adjacent to the transom) prior to lowering of the drilling unit.
FIGS. 5A and 5B shows sample load charts, FIG. 5A indicating exemplary loads before modification, and FIG. 5B after modification). With a conventional support arrangement (i.e., cantilever without added support, as shown on 5 A, only 45 percent of the envelope is rated at full load (100%), where the extremities are reduced to 26 percent of the load rating.
After modification, with the auxiliary stern reaction frames, as shown on 5 B, the full load rating can be maintain nearly the entire drilling envelope, 90 percent, and the extremities are reduced to 76 percent only.
As shown in FIGS. 6 and 7 , an exemplary system for tensioning the conductor pipe utilizes first 16 and second 16 ′ tension members, each having first 17 and second 17 ′ ends, the first ends 17 engaging the tensioning unit, the second ends 17 ′ engaging cantilever beams 2 , 2 ′, respectively. This concept shows a portable support structure 12 for the tensioning unit 13 which stabilizes the conductor 14 in an open water location under load from sea current and waves.
FIGS. 8A-8C illustrate an exemplary reaction frame configuration suitable for reaction frames 7 , 7 ′ discussed earlier in the application. As shown, the reaction frame RF comprises a body 40 having an upper edge 43 having first 44 and second 44 ′ ends, a top 31 and a bottom 31 ′, the first end having formed therein upper 41 and lower 41 ′ mounts, said mounts formed to selectively engage upper and lower base supports 50 , 50 ′, respectively. Said base supports emanate from, or are otherwise securely anchored to, the vessel (in this example, the transom of the vessel). Preferably, the upper and lower base supports 50 , 50 ′ are securely integrated through the transom to the bulkhead(s) 39 (which may be further reinforced for increased load bearing and distribution) of the vessel, so as to distribute the load to the structure of the vessel. In drilling units, in general there is a bulkhead inline with the cantilever beams connecting to the transom, which said base supports may integrate with through the transom, so that the load supported by the reaction frames would be transferred to the transom and longitudinal bulkhead simultaneously.
The upper 41 mount and lower 41 ′ mounts pivotally engage the upper and lower base supports 50 , 50 ′ via pivot pins 45 , 45 ′, respectively, so as to allow the reaction frame to be pivotally 49 , 49 ′ supported by the vessel. It is noted that the pivot pins 45 , 45 ′ are not designed to support the reaction frame when in use (i.e., the pivot pins in the present configuration are not configured to support added load); rather, the pivot pins are intended for use during storage and deployment, i.e., for pivoted each reaction frame to and from the storage position, as well as retaining each reaction frame in a storage position, adjacent to the transom or other location on the vessel or structure
Formed through the upper mount 41 of the reaction frame and the primary base support 50 on the vessel are bores 51 , 51 ′, respectively, said bores formed in a fashion such that, when the reaction frame RF is pivotally 49 ′ positioned at its deployed position relative to the transom (as shown in FIG. 8A ), the bores are in axial alignment 53 (specifically, bore 51 is positioned so as to align with bore 51 ′), so as to receive a load pin 52 therethrough, further, the upper mount 41 is positioned above the upper base support, for support therefrom, while the lower mount 41 ′ is positioned above and supported by the lower base support 50 ′, thereby placing the reaction frame in an engaged, load bearing configuration with regard to the upper and lower base supports 41 , 41 ′, and the load pin, such that load on the support surface 29 is transferred through upper 41 and lower 41 ′ mounts to upper 50 and lower 50 ′ base supports, respectively, which load passes on to the vessel.
Because of the incidence of the reaction frame with the bearing surfaces, the load pins are not particularly envisioned for use as a pivot, but rather to place the configuration into a load bearing configuration. Furthermore, to suit specific needs, the load pins may be engineered to have a profile other than cylindrical so as to resist pivoting.
When mounted in the deployed configuration, above, the lower base support 50 ′ receives loads from the reaction frame transmitted via two forces; the horizontal load 56 and the vertical 57 load, which are met with horizontal 58 and vertical 59 reaction efforts from the hull via bearing surfaces 60 , 54 . Likewise, the upper base support 50 receives loads from the reaction frame transmitted via two forces, the horizontal 56 ′ load and the vertical 57 ′ load, which are met with horizontal 58 ′ and vertical 59 ′ reaction efforts from the hull via the installed 48 pivot pin 52 and upper base support 50 . The framework is thereby designed to transmit the reaction forces back to the main deck, cantilever support bulkheads, inner bottom and bottom structure.
An attribute or appendage 55 associated with the lower base support 50 ′ is shown as well, and depending on the loading, this appendage also can be used to transmit some of the vertical load by providing vertical support to the lower mount 41 ′ at bearing surface 54 .
In the preferred embodiment of the present invention, the pivot points are auxiliary and are positioned off center and separate from the load pin, for space conservation, as well as to provide a better incidence between the 2 bearing surfaces at the bottom, where the pivot point is offset from the 2 bearing surfaces (similar to a hinge mechanism).
As earlier indicated, the second end 44 ′ of the reaction frame is provided with support surface 29 . The support surface may include a raised engagement portion 46 which may be formed into the body, or may comprise a separate component, which may be adjustable as to height (i.e., vertically 38 adjustable via threaded engagement 37 , for example) or location on the upper edge 43 , the support surface formed to engage the underside of the cantilever beam(s), or otherwise engage and support the cantilever structure.
The engagement portion 46 may comprise a bearing surface of, for example, bronze, to provide low friction and corrosion resistance. The engagement portion (also may be referenced as a load pad) ideally will be adjustable to account for cantilever beam deflection under its own weight. A tapered bearing housing mounted on a slope may be provided for this purpose, which bearing housing may be selectively lockable at different positions to adjust the cantilever beam underside.
While the preferred embodiment of the auxiliary support structure of the present invention is shown as pivotal from a stowed to a deployed position, this pivotal operation is shown only as an example, and is not intended to be limiting. For example, other auxiliary support structures may also work in suitable fashion to accomplish the goals of the present invention which could comprise, for example, quick mount units engaging mounting brackets on the transom or other portion of the vessel which may be mounted prior to deploying the cantilever beam, and removed after retracting the cantilever beam, as required.
Further, mechanical devices may be utilized to position the reaction frames, adjust the raised engagement portion 46 , or to install or remove the load pins into the system, as required.
LIST OF ELEMENTS
# Description
R 1 point
R 2 point
R 3 support points
1 vessel
1 jack up vessel
2 cantilever beam
3 drill floor
4 platform jacket
4 platform
5 platform deck
6 drilling template
7 ,′ first and second stern reaction frames
8 drilling envelope
9 load charts before modification
10 “after modification
11 transom
12 portable support structure
13 tensioning unit
14 conductor
15 cantilever structure
16 , 16 ′ first, second conductor tensioning members
17 first second ends
18
19
20 elevated
21 positioned
22 adjacent to
23 working position
24 retracted/stowed
25 deployed cantilever
26 pivoted
27 ,′ deployed support/reaction frame
28 above
29 ,′ support surface
30 well center
31 , 31 ′ top, bottom
32 ,′
33 ,′
34 cantilever beam working envelope
35 distance support point 29 is projected by reaction frame (Example about ⅓ 34 )
36
37 threaded engagement
38 vertically adjustable
39 bulkhead
RF Reaction frame
40 body
41 ,′ upper, lower mounts
42 support surface
43 upper edge
44 ,′ first, second ends
45 pivot pin
46 raised engagement portion
47 upper, lower support members
48 installed
49 pivot
50 ,′ upper, lower base supports
51 ,′ longitudinally aligned bores
52 load pin
53 axial alignment
54 bearing surface
55 appendage
56 horizontal load
57 vertical load
58 horizontal reaction effort
59 vertical reaction effort
60 bearing surface
The invention embodiments herein described are done so in detail for exemplary purposes only, and may be subject to many different variations in design, structure, application and operation methodology. Thus, the detailed disclosures therein should be interpreted in an illustrative, exemplary manner, and not in a limited sense.
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A retractable stern reaction frame for reinforcing self elevating platform cantilever beams. The preferred embodiment contemplates a support framework mounted on a self elevating platform transom and positioned to engage the cantilever to project the reaction point farther towards the cantilever reach. The frameworks are to be retractable (or portable) to allow the self elevating unit to position itself closer to the jackets than would otherwise be possible. The framework is designed to transmit the reaction forces back to the main deck, cantilever support bulkheads, inner bottom and bottom structure.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of copending U.S. patent application Ser. No. 09/416,416, filed Oct. 12, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus and methods for removing resist (photoresist) films, indispensable to photolithographic processes for making minute structures of semiconductor integrated circuits or the like.
2. Description of the Related Art
As techniques for removing resist films, presently known are ashing methods in which a resist film to be removed is ashed with oxygen plasma, and heating and dissolving methods in which a resist film to be removed is dissolved using an organic solvent, such as a phenol- or halogen-base organic solvent, with being heated at 90 to 130° C., or using concentrated sulfuric acid and hydrogen peroxide. Any of these techniques requires a certain time, much energy and a specific chemical material for decomposing or dissolving the resist film. This was a strain on the photolithographic process. In spite of a great demand for new resist removing techniques to replace the above techniques by ashing or dissolving, developments of peeling techniques are yet few. As a representative of such peeling techniques, a new technique has been developed in which a peeling liquid newly developed and the peeling action of high-frequency supersonic waves are used. As such a peeling liquid, the peeling action of “an IPA-HzOz-base ingredient+salt such as fluoride” has been appreciated.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide resist film removing apparatus and methods in which resist films can be peeled off by using a change in physical properties and a change in structure of the resist films due to application of steam and ultraviolet rays, and thereby to realize breakaway from much resources/energy consumption type techniques, that is, to realize environment-symbiosis type techniques by which resist films can be removed independently of the quantity of energy and kinds of chemical solvents.
More specifically, the present invention is directed to removal of resist films by using a change in physical properties, such as softening, expansion, hydration, swelling, or solidification, or a change in structure, such as cross-linking, oxidation, or decomposition, of the resist films due to application of steam and ultraviolet rays. Additive ingredients for promoting such a change in quality may be selectively used.
In other words, the present invention is directed to removal of resist films by a timely cross-combination, a spatially proper cross-combination, a proper cross-combination on temperature, or a chemically proper cross-combination of all or some of means for (or process of) spraying steam, compressed water, or compressed carbonic acid gas onto a resist film, means for (or process of) adding a chemical ingredient to the steam or compressed water, means for (or process of) heating or cooling the substrate holding thereon the resist film, and means for (or process of) irradiating the resist film with ultraviolet rays.
The present inventors have taken up the following elemental techniques as subjects, and studied and developed them:
Change in quality of resist films by steam;
Chemical promotion of quality change of resist films; and
Promotion of quality change of resist films by irradiation with ultraviolet rays.
According to an aspect of the present invention, an apparatus for removing a resist film used in a lithographic process, comprises: means for bringing steam into contact with the resist film; and means for spraying steam onto the resist film, wherein the resist film is peeled off by an action of steam.
According to an aspect of the present invention, the resist film is peeled off with saturated or superheated steam at a temperature within the range of 70° C. to 200° C.
According to an aspect of the present invention, an apparatus for removing a resist film used in a lithographic process, comprises: means for spraying saturated steam onto the resist film, wherein the resist film is peeled off by an action of the saturated steam.
According to an aspect of the present invention, the temperature of the saturated steam at the target surface is within the range of 70° C. to 100° C.
According to an aspect of the present invention, steam containing an ingredient for promoting a change in quality of the resist film is brought into contact with and/or sprayed onto a surface of the resist film to peel the resist film.
According to an aspect of the present invention, the apparatus comprises a steam supply system including a subsystem for generating steam, a subsystem for heating steam, a subsystem for controlling the water quantity to be supplied and the heat amount for heating, and a subsystem for controlling the pressure of steam. The steam supply system is connected to an ultrapure water supply line for selectively supplying saturated or superheated steam at a temperature within the range of 70° C. to 200° C.
According to an aspect of the present invention, the steam supply system further includes a subsystem for switching lines between the ultrapure water supply line and a line for a solution containing an ingredient for promoting a change in quality of the resist film, and an injecting pump for the ingredient, so that steam containing the ingredient and steam not containing the ingredient can be switched over.
According to an aspect of the present invention, the apparatus further comprises an ultraviolet reactor including an ultraviolet lamp of a wavelength corresponding to a transmissive distance of not less than 10 mm to steam. The ultraviolet lamp is disposed in parallel with a substrate surface on which the resist film is formed. The substrate surface can be irradiated while and after the resist film is peeled off the substrate surface by the action of steam.
According to an aspect of the present invention, the apparatus further comprises a chamber provided with a system for taking in a substrate on which the resist film is formed and taking out the substrate off which the resist film has been peeled, a system for purging an atmosphere in the chamber, a system for discharging gas or liquid from the chamber, a system for introducing steam into the chamber, and a system for driving a steam spraying nozzle to move relatively to the substrate surface on which the resist film is formed, so as to sweep the substrate surface. The steam spraying nozzle sprays steam onto the substrate surface to peel the resist film off the substrate surface.
According to an aspect of the present invention, the chamber is further provided with a system for supplying carbonic acid gas from a gas bomb into the chamber, and a gas spraying nozzle for spraying carbonic acid gas onto the substrate surface rapidly to cool the resist film to be peeled off.
According to an aspect of the present invention, the apparatus further comprises a supply line for a liquid chemical for cleaning a substrate, connected to the steam supply system, wherein the substrate off which the resist film has been peeled is cleaned by irradiation with ultraviolet rays and spraying steam, and then dried by spraying superheated steam.
According to an aspect of the present invention, the apparatus further comprises a filter for filtering off pieces of the resist film having been peeled off a substrate and contained in a liquid being discharged, or a centrifugal separator for separating the pieces from the liquid, wherein the liquid from which the pieces have been removed is reused.
According to an aspect of the present invention, a method for removing a resist film used in a lithographic process, comprises steps of: bringing saturated or superheated steam into contact with the resist film; and spraying saturated or superheated steam onto the resist film, wherein the resist film is peeled off by an action of steam.
According to an aspect of the present invention, steam containing an ingredient for promoting a change in quality of the resist film is brought into contact with a surface of the resist film to peel the resist film.
According to an aspect of the present invention, in a method for removing a resist film used in a lithographic process, saturated steam is sprayed onto the resist film, and the resist film is peeled off by an action of the saturated steam.
According to an aspect of the present invention, the temperature of the saturated steam at the target surface is within the range of 70° C. to 100° C.
According to an aspect of the present invention, a substrate surface on which the resist film is formed, is irradiated with excimer ultraviolet rays of a wavelength corresponding to a transmissive distance of not less than 10 mm to steam, while and after the resist film is peeled off the substrate surface by the action of steam.
According to an aspect of the present invention, organic, metallic, and granular contaminants are removed from a substrate surface off which the resist film has been peeled, by spraying steam with irradiating the substrate surface with ultraviolet rays, and then the substrate surface is cleaned and dried by spraying steam.
According to an aspect of the present invention, steam containing an ingredient for promoting a change in quality of the resist film is brought into contact with and/or sprayed onto a surface of the resist film to peel the resist film.
According to an aspect of the present invention, an apparatus for removing a resist film used in a lithographic process, comprises: means for making steam act on the resist film, wherein the resist film is peeled off by the action of the steam.
According to an aspect of the present invention, the steam is saturated steam, and the temperature of the saturated steam at the target surface is within the range of 70° C. to 100° C.
According to an aspect of the present invention, steam containing an ingredient for promoting a change in quality of the resist film is made to act on a surface of the resist film to be peeled off.
According to an aspect of the present invention, the apparatus further comprises at least one of: means for making water act on the resist film; means for making vapor of isopropyl alcohol act on the resist film; means for making compressed carbonic acid gas act on the resist film; means for adding a chemical ingredient into the steam and/or the water; means for irradiating the resist film with ultraviolet rays; means for applying high-frequency supersonic waves to the resist film; and means for cooling a substrate on which the resist film is formed, wherein the resist film is peeled off by properly cross-combining at least one of time and/or spatial conditions, conditions on temperature, and physical and/or chemical conditions for operating each of the means.
According to an aspect of the present invention, the apparatus further comprises a one-by-one process chamber in which substrates to be processed are disposed one by one. The chamber is provided with a system for taking in and out the substrates, a system for purging the atmosphere in the chamber, and a system for discharging gas or liquid from the chamber, in addition to the above means. The chamber is further provided with a driving system for at least one of the means for making steam act on the resist film, the means for making water act on the resist film, and the means for making compressed carbonic acid gas act on the resist film, to move relatively to the front or back surface of each substrate.
According to an aspect of the present invention, as the above time and/or spatial conditions for operating the above means and/or the above systems, the order of the operations and the intervals of the operations are properly cross-combined in relation to the portions subjected to the operations, i.e., the surface of the resist film, both or one of the front and rear surfaces of the substrate, or part of the front or rear surface of the substrate.
According to an aspect of the present invention, as the above conditions on temperature for operating the above means and/or the above systems, process temperatures and the raising and lowering speeds thereof are properly cross-combined in relation to the portions subjected to the operations, i.e., the surface of the resist film, both or one of the front and rear surfaces of the substrate, or part of the front or rear surface of the substrate.
According to an aspect of the present invention, as the above physical and/or chemical conditions for operating at least one of the means for adding a chemical ingredient into the steam and/or the water, the means for irradiating the resist film with ultraviolet rays, and the means for applying high-frequency supersonic waves to the resist film, the compositions of chemical ingredients for the steam and/or the water, the frequencies of supersonic waves, and the wavelengths of ultraviolet rays are properly cross-combined.
According to an aspect of the present invention, the above time and/or spatial conditions, the above conditions on temperature, and the above physical and/or chemical conditions are properly cross-combined with one another.
According to an aspect of the present invention, the means for making steam act on the resist film has the function of bringing the steam into contact with the resist film and the function of spraying the steam onto the resist film. The contact process and the spraying process are properly cross-combined.
According to an aspect of the present invention, the means for making steam act on the resist film has the function of making saturated steam act on the resist film and the function of making superheated steam act on the resist film. The saturated steam process and the superheated steam process are properly cross-combined.
According to an aspect of the present invention, the steam process by the means for making steam act on the resist film, and a chemical ingredient composition determined by the means for adding a chemical ingredient into the steam are properly cross-combined.
According to an aspect of the present invention, the steam process by the means for making steam act on the resist film, and the water spraying process by the means for making water act on the resist film are properly cross-combined.
According to an aspect of the present invention, the steam process by the means for making steam act on the resist film, and the ultraviolet irradiation process by the means for irradiating the resist film with ultraviolet rays are properly cross-combined.
According to an aspect of the present invention, the steam process by the means for making steam act on the resist film, and the high-frequency supersonic application process by the means for applying high-frequency supersonic waves to the resist film are properly cross-combined.
According to an aspect of the present invention, the steam process by the means for making steam act on the resist film, and the compressed carbonic acid gas spraying process by the means for making compressed carbonic acid gas act on the resist film are properly cross-combined.
According to an aspect of the present invention, the steam process by the means for making steam act on the resist film, and the cooling process by the means for cooling a substrate on which the resist film is formed, are properly cross-combined.
According to an aspect of the present invention, the steam process by the means for making steam act on the resist film, and the vapor process by the means for making vapor of isopropyl alcohol act on the resist film are properly cross-combined.
According to an aspect of the present invention, the compressed carbonic acid gas spraying process by the means for making compressed carbonic acid gas act on the resist film, and the ultraviolet irradiation process by the means for irradiating the resist film with ultraviolet rays are properly cross-combined.
According to an aspect of the present invention, by properly cross-combining the above time and/or spatial conditions, the above conditions on temperature, and the above physical and/or chemical conditions for operating the above means and/or the above systems, the substrate surface off which the resist film has been peeled is processed to remove residues of the resist film and alien substances. The substrate surface is thereby purified.
According to an aspect of the present invention, a method for removing a resist film used in a lithographic process, comprises a step of making steam act on the resist film, wherein the resist film is peeled off by the action of the steam.
According to an aspect of the present invention, the method further comprises at least one of: a step of making water act on the resist film; a step of making vapor of isopropyl alcohol act on the resist film; a step of making compressed carbonic acid gas act on the resist film; a step of adding a chemical ingredient into the steam and/or the water; a step of irradiating the resist film with ultraviolet rays; a step of applying high-frequency supersonic waves to the resist film; and a step of cooling a substrate on which the resist film is formed, wherein the resist film is peeled off by properly cross-combining at least one of time and/or spatial conditions, conditions on temperature, and physical and/or chemical conditions for performing each of the steps.
According to an aspect of the present invention, as the above time and/or spatial conditions for performing the above steps, the order of the steps and the intervals of the steps are properly cross-combined in relation to the portions subjected to the steps, i.e., the surface of the resist film, both or one of the front and rear surfaces of the substrate, or part of the front or rear surface of the substrate.
According to an aspect of the present invention, as the above conditions on temperature for performing the above steps, process temperatures and the raising and lowering speeds thereof are properly cross-combined in relation to the portions subjected to the steps, i.e., the surface of the resist film, both or one of the front and rear surfaces of the substrate, or part of the front or rear surface of the substrate.
According to an aspect of the present invention, as the above physical and/or chemical conditions for performing at least one of the step of adding a chemical ingredient into the steam and/or the water, the step of irradiating the resist film with ultraviolet rays, and the step of applying high-frequency supersonic waves to the resist film, the compositions of chemical ingredients for the steam and/or the water, the frequencies of supersonic waves, and the wavelengths of ultraviolet rays are properly cross-combined.
According to an aspect of the present invention, the above time and/or spatial conditions, the above conditions on temperature, and the above physical and/or chemical conditions are properly cross-combined with one another.
According to an aspect of the present invention, the step of making steam act on the resist film includes a sub-step of bringing the steam into contact with the resist film and a sub-step of spraying the steam onto the resist film. The contact process and the spraying process are properly cross-combined.
According to an aspect of the present invention, the step of making steam act on the resist film includes a sub-step of making saturated steam act on the resist film and a sub-step of making superheated steam act on the resist film. The saturated steam process and the superheated steam process are properly cross-combined.
According to an aspect of the present invention, the steam process by the step of making steam act on the resist film, and a chemical ingredient composition determined in the step of adding a chemical ingredient into the steam are properly cross-combined.
According to an aspect of the present invention, the steam process by the step of making steam act on the resist film, and the water spraying process by the step of making water act on the resist film are properly cross-combined.
According to an aspect of the present invention, the steam process by the step of making steam act on the resist film, and the ultraviolet irradiation process by the step of irradiating the resist film with ultraviolet rays are properly cross-combined.
According to an aspect of the present invention, the steam process by the step of making steam act on the resist film, and the high-frequency supersonic application process by the step of applying high-frequency supersonic waves to the resist film are properly cross-combined.
According to an aspect of the present invention, the steam process by the step of making steam act on the resist film, and the compressed carbonic acid gas spraying process by the step of making compressed carbonic acid gas act on the resist film are properly cross-combined.
According to an aspect of the present invention, the steam process by the step of making steam act on the resist film, and the cooling process by the step of cooling a substrate on which the resist film is formed, are properly cross-combined.
According to an aspect of the present invention, the steam process by the step of making steam act on the resist film, and the vapor process by the step of making vapor of isopropyl alcohol act on the resist film are properly cross-combined.
According to an aspect of the present invention, the compressed carbonic acid gas spraying process by the step of making compressed carbonic acid gas act on the resist film, and the ultraviolet irradiation process by the step of irradiating the resist film with ultraviolet rays are properly cross-combined.
According to an aspect of the present invention, by properly cross-combining the above time and/or spatial conditions, the above conditions on temperature, and the above physical and/or chemical conditions for performing the above steps, the substrate surface off which the resist film has been peeled is processed to remove residues of the resist film and alien substances. The substrate surface is thereby purified.
According to the present invention, by using a change in physical properties (such as swelling) of a resist film by steam and a light decomposition effect by ultraviolet rays, it becomes possible to peel off the resist film easily and surely. As a result, breakaway from much resources/energy consumption type techniques can be realized, that is, an environment-symbiosis type technique independent of the quantity of energy and kinds of chemical solvents can be realized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view showing a portion near a spraying nozzle of a resist removing apparatus according to the present invention;
FIG. 2 is a graph showing the relation of the speed of removing a resist film by steam containing KOH, to the concentration of KOH;
FIG. 3 is a schematic view showing a principal construction of a steam supply apparatus according to an embodiment of the present invention;
FIG. 4 is a schematic view showing a principal construction of a resist removal apparatus according to an embodiment of the present invention;
FIGS. 5A to 5 E are schematic sectional views showing the constructions of samples from each of which a resist film is to be peeled off; and
FIG. 6 is a schematic sectional view of a one-by-one resist film removing apparatus including a spinning mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, preferred embodiments of the present invention will be described.
1. Peeling Resist Film by Steam
Porousness and Hydrogen Bondability of Chemical Structure of Resist Film:
In a photolithographic process for making a minute structure of, e.g., a semiconductor integrated circuit, a resist film is formed on a surface to be processed. Electromagnetic energy is then applied to the resist film through fine pattern gaps provided on an exposure mask. The thus formed pattern is developed in the resist film by using the difference in solubleness to a solvent between irradiated and non-irradiated portions of the resist film. The surface to be processed is then etched using the resist film pattern as an etching mask.
In such photolithographic processes, the wavelength of ultraviolet rays used has gradually become shorter with progress of the generations of degrees of integration. That is, g line, i line, and ArF to F 2 excimer lasers were used in this order. As a matter of course, the chemical structures of resist films have been reformed with shortening the used wavelength, and will be more reformed for future X-ray and electron ray photolithography ages. In reforming the chemical structures of resist films, it is important to grasp the physical properties of the basic structures unchanging fundamentally.
The present inventors have perceived the porousness and the hydrogen bondability of the basic structures of the base polymers of resist films.
Table 1 shows the basic structures of the base polymers of various photoresists from an initial resist KPR to currently mainstream resists, besides, resists for ARF excimer laser.
TABLE 1
Base Polymer Basic Structure of Resist
first generation resist
vinyl cinnamate
resist for g to i line
cyclo-polyisoprene
″
novolac resin
resist for KrF
polymethyl methacrylate
″
polymethyl isopropenyl ketone
″
chloromethyl polystyrene
″
polystyrene sulfone
″
polyvinyl phenol
resist for ArF
alicyclic polymethacrylate
″
polybutene sulfone positive type
The chemical structures of the principal and side chains of these photoresists differ variously. But, in these various basic structures, there are two fundamental points of sameness.
They are the porousness of the basic structures and the hydrogen bondability of the constituent groups. Because of the cyclic structures or the structures having side chains of, e.g., alicyclic groups or phenol groups, the polymer basic structures have considerable spaces therein.
Besides, constituent groups having intensive hydrogen bondability, such as phenol groups, carbonyl groups, or ester groups, have been introduced. Introduction of these groups is necessary for the resists sensitively to react to light energy. Besides, resists must have solubility to developers, and the porousness and hydrogen bondability are physical properties necessary for the solubility.
Besides, the water permeabilities of resists are higher than those of other organic polymers. For example, while the water permeability (Pa·cm 3 ·s −1 ·m −2 ) of Teflon, or polyethylene is about 3×10 −11 , those of resists are 10 −8 to 10 −7 , showing their structures more permeable to water by three to four figures.
It is because the polymer structures of resists are porous in contrast to compactness of organic polymers having structural regularity, and further the polymer structures of resists have hydrogen bondability.
In future, resists will be required to be chemically amplificative, and addition of chemical amplification ingredients will be done.
But, “resist-peeling” is directed by base polymer basic structures. It is a characteristic feature of the present invention to utilize the porousness and hydrogen bondability which are fundamental properties of resists.
Change in Quality of Resist Film by Steam:
The present inventors has perceived the fact that the states of resist films change rapidly and remarkably by steam. Physical changes such as softening/expansion due to hot steam occur naturally; besides, changes in physical properties such as swelling/separation/solidification occur. There have been found changes in chemical structure of the resist films though their aspects vary in accordance with the kinds of resists and conditions of steam. The details of such changes are supposed as follows.
Because the basic structures of the resist base polymers have porousness as described above, the resist transmissivity of steam is very high. A resist film is put in a pyrogenetic chemical reaction system the moment it comes into contact with steam. It is well known that the chemical action of water at a high temperature is intensive, and there are known many instances of hydrolysis of organic compounds by hot water. In a resist chemical structure, side chains having high hydrogen-bondability and photosensitive groups are present. Not only hydrolysis/oxidation of these groups but also cross-linking in the resist basic structure progresses.
Action of Saturated or Superheated Steam:
The temperature of steam necessary for processing a resist film varies in accordance with the kind of resist and conditions of the resist process. The steam temperature is selected to a suitable value of 70° C. to 200° C. The temperature may be more than 200° C. if circumstances of the substrate allow. In ultraviolet irradiation, superheated steam hardly brings about absorption and scattering of ultraviolet rays due to a mist, and it shows high efficiency of ultraviolet transmissivity. Besides, superheated steam is not affected by the mist when drying the surface from which a resist film has been peeled off.
Peeling Swelled Resist Film off Substrate by Spraying Steam:
The power of sprayed steam acts effectively for peeling a swelled resist film off a substrate. The resist film which has been hydrated/swelled and softened by hot steam, a mist, and further a swelling-promotion ingredient, is easily peeled off the substrate surface if the linear velocity of sprayed steam is several m/sec to scores m/sec. The peeling speeds depend on the kinds of resists. In particular, ion-implanted resist films have a tendency to be hard to peel off. Shape of pattern also exerts influence. In particular, high aspect ratio is a cause of the tendency to be hard to peel off. Considering such resist physical properties/substrate structures, the linear velocity and spraying time are controlled. In resist-peeling, it is important to control the spraying linear velocity in order not to damage the minute structure of the exposed surface.
Contact and Spraying of Steam:
Required is an apparatus capable of realizing a combination of a step of bringing a resist film into contact with steam to change the quality of the film, and a step of spraying steam onto the resist film which has changed in quality, to peel off.
The surface structure exposed as a result of resist-peeling must be protected without any damage.
While the power of sprayed steam at a linear velocity of one m/sec to scores m/sec is strong and effective for resist-peeling, it may damage the device surface. A two-step process is effective in which change in quality of a resist film is made to progress in a contact step, and then the film is peeled off in a spraying step of a short time. This is suitable in particular for removing an ion-implanted resist film in which the speed of change in quality is low, or a resist film on a surface where a structural aspect ratio is high.
Resist-peeling Only by Spraying Saturated Steam:
The present inventors have thought out a process of peeling a resist film only by spraying steam containing droplets, i.e., saturated steam, without using the above-described two-step process of the contact and spraying steps of steam.
More specifically, as shown in FIG. 1 for example, to remove a resist film 44 after patterning a SiO 2 film 43 on a substrate 42 , a steam spraying nozzle 41 is disposed to be opposed to the resist film 44 , and steam is sprayed to peel the resist film 44 . In spraying conditions of this case, the temperature of saturated steam at the portion which steam reaches, i.e., the surface portion of the resist film 44 , is controlled within the range of 70° C. to 100° C., more preferably, within the range of 75° C. to 85° C. This is because sprayed steam makes saturated steam containing droplets, suitable for peeling the resist film 44 , at the surface portion of the resist film 44 when the temperature is controlled within the above range. FIG. 1 shows an example for realizing the above temperature range, in which the distance from the spraying nozzle 41 to the surface of the resist film 44 is 10 mm. Besides, the spraying pressure of steam at the mouth of the spraying nozzle 41 is controlled to be less than 10 kg/cm 2 , more preferably, within the range of 1 to 2 kg/cm 2 . If the pressure exceeds 10 kg/cm 2 , the spraying nozzle 41 and device elements formed on the substrate 42 may be adversely affected.
A process in which a contact step uses steam containing an ingredient for promoting change in quality of a resist film as described in the next section, and a spraying step uses pure water steam, is effective for preventing a metal wiring surface from being damaged.
Ingredient for Promoting Change in Quality of Resist:
It has been found that a change in physical properties/structure by hot steam can be accelerated by making the steam contain an ingredient for promoting the change in quality. In particular, a resist film hardened by an ion-implantation process is very hard to peel off. In spite of this fact, however, it can rapidly be peeled off by using steam which contains a promotion ingredient. Since the kind of effective promotion ingredient varies in accordance with the kind of resist, it need be selected individually. Protection of a structural substrate after resist-peeling, e.g., chemical action on a metal surface of a metal wiring substrate need be considered.
Oxidative substances are effective as promotion ingredients for cross-linking or oxidation. For example, hydrogen peroxide can make even an ion-implantation-processed resist film change in quality/be peeled off in a short time. We suppose that it is by oxidation of chemical bonding in the resist because of intensive radical reaction. Ozone water is also effective as a promotion ingredient for oxidation.
Also usable are other oxidative substances, such as Cl 2 —H 2 O, Br 2 —H 2 O, I 2 —KI, NaClO, NaClO 4 , KMnO 4 , K 2 CrO 7 , and Ce(SO 4 ) 2 .
Alkali is a highly effective promotion ingredient. For example, usable is an aqueous solution of caustic alkali at a pH value of 8 to 14, more preferably, 10 to 12. It gives the resist surface wettability/permeability, and makes the peeling-off action rapid. As alkali, usable are KOH, NaOH, NaCO 3 , Ca(OH) 2 Ba(OH) 2 , NH 4 OH, TMAH, etc.
More specifically, examined were the removing speeds of resist films which were used as a mask for ion implantation of impurities (As), when the resist films were removed using the technique shown in FIG. 1 and using KOH of alkali as a resist quality change promotion ingredient. FIG. 2 shows the result of measurement. In FIG. 2, the axis of abscissas represents the concentration (wt. %) of KOH, and the axis of ordinates represents the removing speed (sec). As shown in FIG. 2, the higher the KOH concentration is, the higher the removing speed is. This shows that the higher KOH concentration brings about the more efficient resist-peeling. However, too high KOH concentration may cause an adverse affection on a device material, so it is seemed that about 0.1 (wt. %) or less is proper.
Also acids and oxidative acids are promotion ingredients for change in quality. For example, H 2 SO 4 makes a resist cross-link strongly. Usable are H 2 SO 4 , HNO 3 , HClO, HClO 4 , HCl, HF, etc.
Surface active agents have interfacial osmotic actions and surface functions for preventing peeled resist thin pieces from again adhering to the surface which they have been peeled off. As such surface active agents, usable are anionic, cationic, and nonionic surface active agents whose contact angles to resist surfaces are not more than 30 degrees, more preferably, not more than 20 degrees.
2. Peeling Resist Film by Ultraviolet Rays
(1) Decomposition of Resist Film by Ultraviolet Rays:
Table 2 shows experimental data of decomposition tests of photoresists by ultraviolet rays. Light-decomposition of photoresists is possible by using a Xe excimer lamp (wavelength: 172 nm) as an ultraviolet lamp. But, the decomposition speed is too low to apply to removal of resist films. Although there is an attempt of acceleration by existence of ozone at a high concentration, putting it to practical use faces many hurdles.
TABLE 2
Decomposition of Photoresist by Ultraviolet Rays
de-
crease
theoretical
untraviolet
in film
speed of
speed of
irradiation
thick-
decomposi-
decomposi-
quantum
time
ness
tion
tion
efficiency
photoresist
(sec)
(μm)
(nm/sec)
(nm/sec)
(%)
positive
2700
700
0.26
0.12
47
type resist
1400 μm
thick
Xe excimer light source: wavelength of 172 nm;
irradiation light quantity: 10 mW/cm 2 on the outside of light source chamber window board
sample surface irradiation conditions: air layer between light source and resist surface (distance=2 mm), surface temperature of 80° C.
The present inventors have perceived a change in quality of resists by ultraviolet rays. It aims not at resist decomposition but at resist-peeling. Since ultraviolet photons have strongly promoting actions for cross-linking or oxidation, the action of changing the quality of resists is intensive. An incorporated effect with a quality-change effect by steam is used. Besides, since ultraviolet rays have high resist transmissivity, they can fully reach the boundary layer of resist/substrate. It is an intensive permeating action. A change in quality of the boundary layer is directly related to the peeling effect.
3. Steam Supply Apparatus
FIG. 3 shows the fundamental construction of a steam supply apparatus. An evaporator 1 and a heating block 2 for generating saturated steam, and a superheater 3 and a heating block 4 for generating superheated steam, are disposed between a fixed flow rate pump 5 and a pressure control needle valve 6 . The internal pressure of this steam generation system is measured with a pressure gauge 7 . The temperatures of saturated and superheated steams are measured with thermometers 8 and 9 , respectively. The heating area in the evaporator 1 is so designed as to satisfy the burnout point condition of a boiling characteristic curve.
Switching Between Steam of Pure Water and Steam Containing Promotion Ingredient:
When steam of ultrapure water is generated, a valve 10 for an ultrapure water line is opened. When steam containing a promotion ingredient is generated, a valve 11 for an aqueous solution line is opened.
Switching Between Saturated and Superheated Steams:
When saturated steam is supplied, the heating block 4 for superheating is not supplied with heats. At this time, the superheater 3 merely functions as a passage for steam. When superheated steam is supplied, the heating block 4 is supplied with heats to perform superheating by the superheater 3 .
Switching Between Steam-contact and Steam-spraying:
When steam is introduced into a process chamber 15 , an introduction valve 12 is opened. When steam is sprayed onto a surface to be processed, a steam-spraying valve 13 is opened and steam is sprayed onto the surface 16 to be processed, through a steam-spraying nozzle 14 .
Table 3 exemplifies control conditions for steam supply. Table 4 exemplifies conditions of the steam spraying nozzle. The nozzle shape/steam quantity/spraying velocity can freely be designed so as to meet the purpose.
TABLE 3
Control Condition for Steam Supply
water supply
superheated steam
quantity and
saturated steam generation
generation conditions
heat
conditions
tem-
quantity
internal
tempera-
steam
internal
pera-
steam
ml/
pressure
ture
quantity
pressure
ture
quantity
sec
KWH
Kg/cm 2
° C.
L/sec
Kg/cm 2
° C.
L/sec
1.5
3.9
1.0
100
2.55
—
—
—
1.5
3.9
2.0
120
2.69
1.00
120
2.69
1.5
4.0
3.6
140
2.83
1.00
140
2.83
1.5
4.0
6.0
160
2.96
1.00
160
2.96
water supply quantity temperature: 20° C.; quantity of heat: net value (except radiation loss)
saturated steam: exemplified are only cases of 100 to 160° C.
superheated steam: exemplified are only cases of 100° C. saturated superheated steam generation
TABLE 4
Condition Example of Steam-spraying Nozzle
point nozzle
line slit nozzle
steam-
steam-spraying
spraying
steam
linear
linear
quantity
nozzle
velocity
velocity
L/sec
shape
m/sec
nozzle shape
m/sec
2.55
inside
120
200 mm × 0.5 mm
52
diameter
of 5 mm
2.55
inside
32
200 mm × 1.0 mm
13
diameter
of 10 mm
4. Ultraviolet Reactor
Selections of the ultraviolet wavelength and time characteristics of a lamp used in an ultraviolet reactor are important technical factors.
Selection of Ultraviolet Wavelength:
The shorter the ultraviolet wavelength is, the greater the energy is and the lower the transmissivity to the irradiation atmosphere is. The ultraviolet wavelength must be so selected as to satisfy the objective transmissivity.
A relation between the light absorption sectional area of molecules present in the atmosphere and the light transmissivity, is given by expression (1).
Logarithms of the transmissivity are proportional to distances. The present inventors use 50% transmissive distance as an index. This 50% transmissive distance is given by expression (2). Table 5 shows relations between ultraviolet wavelengths and 50% transmissive distances to air, water, and steam obtained by expression (2) or actual measurements. For example, the 50% transmissive distance of ultraviolet rays of the wavelength of 172 nm to air is obtained as 3.1 mm from the light absorption sectional area of oxygen (0.259×10 −19 molecules/cm 2 ) while the actual measurement of 2.2 mm was obtained. Both are practically almost equal.
δ CL=ln ( I°/I )
δ: light absorption sectional area (molecules/cm 2 ) O 2 . . . 0.259×10 −19
C: molecule concentration (partial pressure of molecule)
L: transmissive distance (cm)
I 0 /I: light transmissivity=incident light intensity/transmitted light intensity . . . (2)
δCL 50 =ln (100/50)
L 50 : 50% transmissive distance
TABLE 5
Ultraviolet Wavelength and 50% Transmissive distances
to Air/Water/Steam
50% transmissive distance
excimer
wavelength
energy
air
water
steam
ultraviolet lamp
nm
eV
mm
mm
mm
Xe excimer lamp
172
7.21
3
ArCl excimer lamp
175
7.08
6
<10
<10
185
6.70
40
10
>1 × 10 4
KrI excimer lamp
191
6.49
100
28
ArF excimer lamp
193
6.42
>100
42
KrBr excimer lamp
207
5.99
>100
KrCl excimer lamp
222
5.58
low pressure
185 · 254
mercury lamp
i-line lamp
365
3.41
Selection of Time Response:
An ultraviolet lamp is selected in accordance with the type of ultraviolet process, i.e., which of a moment type and a constant type is performed.
An ultraviolet excimer lamp can be used in a moment-type process. It reaches its stationary state in several seconds after being lit.
It is suitable for a sequential process in seconds in a one-by-one ultraviolet process. A low pressure mercury lamp, an i-line lamp, or the like, can be used in a constant-type process. Although they require scores minutes for reaching their stationary states after being lit, they are stable after then.
5. One-by-one Resist-peeling Apparatus
(1) Construction of Apparatus:
A one-by-one resist-peeling apparatus comprises a steam process chamber and an ultraviolet lamp chamber.
The steam process chamber has a substrate taking-in/out system, an atmosphere purge system, and a liquid discharge system. In the chamber, a driving system is provided for moving a steam-spraying nozzle relatively to a substrate surface to be processed, so as to sweep the substrate surface. A point nozzle or a line slit nozzle is disposed in the chamber.
FIG. 4 shows a one-by-one resist-peeling apparatus including a spinning mechanism. This apparatus comprises a steam process chamber 23 provided with a spinning mechanism 22 for rotating a substrate 21 , and a lamp chamber 26 including an ultraviolet lamp 24 and having a quartz window board 25 . A gas inlet 27 to the chamber and a discharge duct 28 are accompanied.
When steam is introduced into the process chamber from the steam supply apparatus (see FIG. 3 ), the steam introduction valve 12 is opened. When steam is sprayed onto a surface to be processed, the steam-spraying valve 13 is opened and steam is sprayed onto the surface of the substrate 21 through the steam-spraying nozzle 14 .
Shown is an example of the steam-spraying nozzle 14 in which a line slit nozzle is disposed in a radial direction.
Alternatively, usable is a system including a spot nozzle driven radially, or several nozzles movable in a proper distance or fixed. The spraying angle and spraying distance of the nozzle and the linear velocity of sprayed steam are optimized in various respects, such as the object of the process, the surface structure of the substrate, and protection for damage.
The steam process chamber 23 is kept in temperature. Steam is condensed little by little on the inner wall of the chamber. It serves for cleaning the inner wall. In this manner, the interior of the chamber is always kept clean.
The gas inlet 27 to the chamber is used for changing the atmosphere when a substrate is taken in/out. It is used also for adding an ingredient effective for the process, to the atmosphere. The discharge duct 28 preferably has a cooling structure.
(2) Physical Peeling Promotion:
Quenching (Rapidly Cooling) Resist Film:
Although not shown in FIG. 4, a carbonic acid gas-spraying nozzle can be disposed to be opposite to a substrate surface. It is for spraying carbonic acid gas and the resultant dry ice particles onto the substrate surface to quench (cool rapidly) the resist film. The resist film which was heated and swelled, shrinks/solidifies and is peeled off the substrate. It has been confirmed that such a quenching process promotes the peeling-off operation of some kinds of resists.
High-speed Spinning:
When the number of revolution of the substrate is set at 2000 rpm or more using the spinning mechanism, the peeling-off operation is promoted. In particular, the peeling-off operation is promoted when the steam-spraying effect is weak on the peripheral portion.
6. Making Resist-peeling Process and Surface-cleaning Process after Peeling Off, Sequential
A resist-peeling process and a surface-cleaning process after resist-peeling can be a sequential process.
Switching from the resist-peeling apparatus to a surface-cleaning apparatus after resist-peeling is simple.
By altering the aqueous solution line 11 of the steam supply apparatus of FIG. 3 into a switching system between a peeling-promotion solution line 11 A and a surface-cleaning solution line 11 B, the resist-peeling apparatus and a surface-cleaning apparatus after resist-peeling can be switched freely.
Since the combination of the steam and ultraviolet processes effectively shortens both the peeling time and the cleaning time, the unity of the processes can be realized with no decrease in throughput.
EXAMPLE
Hereinafter, specific examples of the present invention will be described. Although the description is omitted in each example, the resist-peeling state is obtained by observing the peeled surface at each spraying time with an optical microscope.
Example 1
Shown are examples of peeling resist films by steam of pure water.
Sample: FIG. 5A; a resist film formed on a dry-etched thermal oxidation film;
FIG. 5B; a resist film formed on a dry-etched gate electrode (polysilicon film)
Steam: steam of pure water
Result of Peeling:
As shown in the below Table 6, peeling could be performed by spraying for thirty seconds to one minute.
TABLE 6
Steam Effect and Peeling Result
pure-water
spraying time
steam
15 sec
30 sec
1 min
oxide film dry-
100° C.
partially
fully peeled
etched surface
saturated
remained
steam
gate electrode
100° C.
—
partially
fully peeled
etched surface
saturated
remained
steam
steam quantity: 2.55 L/sec; point nozzle: inside diameter of 10 mm, 32 m/sec
Example 2
Shown are examples of peeling resist films by steam containing promotion ingredients.
The resist films have been ion-implanted and are known to be very hard to peel off.
Sample: FIG. 5C; silicon thermal oxidation film dry-etched; its underlayer of a silicon substrate ion-implanted;
Ion-implantation conditions: acceleration energy of 80 keV; dose amount of phosphorus of 6×10 15 /cm 2 ;
Promotion ingredient-containing steam: promotion ingredient; alkali (KOH) and a surface active agent.
Result of Peeling:
As shown in Table 7, peeling could be performed by spraying steam for two minutes. In case of the promotion ingredient of alkali, some peeled-off pieces adhering to the surface after peeling were observed. But, in case of the promotion ingredient of alkali+surface active agent, no peeled-off piece is found.
TABLE 7
Effect of Quality-change Promotion Ingredient and
Peeling Result
quality-
change
promotion
spraying time
ingredient
1 min
2 min
oxide film
alkali
partially
fully peeled
etched/ion-implanted
remained
(peeled-off pieces
surface
adhered)
oxide film
alkali +
partially
fully peeled
etched/ion-implanted
surface
remained
(no peeled-off piece
surface
active agent
adhered)
Example 3
Shown are further examples of peeling resist films by steam containing promotion ingredients.
Sample: FIG. 5D; silicon thermal oxidation film wet-etched; a negative-type resist film;
FIG. 5E; after etching metal wiring; a positive-type resist film;
Promotion ingredient-containing steam: promotion ingredient; hydrogen peroxide and a surface active agent.
Result of Peeling:
The resist film was fully peeled off the surface of the thermal oxidation film by spraying steam containing the promotion ingredient for one minute. The resist film was fully peeled even off the etched metal wiring/ion-implanted surface inferior in ability of peeling, in two minutes.
TABLE 8
Effect of Quality-change Promotion Ingredient and
Peeling Result
quality-
change
promotion
spraying time
ingredient
30 sec
1 min
2 min
oxide film wet-
hydrogen
partially
fully peeled
etched surface
peroxide
remained
metal wiring
hydrogen
partially
fully peeled
etched/ion-implanted
peroxide
remained
surface
Example 4
Shown are examples by two-step steam processes for metal-wiring surfaces.
Object of two-step process: it aims at avoiding chemical damage to metal wiring. A promotion ingredient is used when the metal-wiring surface is covered with a resist film. No promotion ingredient is used after the resist film is peeled off the metal-wiring surface to be exposed.
Details of two-step process:
first step (steam-contacting process); using steam containing alkali;
second step (steam-spraying process); using steam of pure water.
Result of Peeling:
Table 9 shows the results. The resist film was removed by the steam process of the second step for thirty seconds, and the metal wiring was not damaged.
For comparison, an example of process only with steam containing alkali is shown. This case required two minutes of spraying time, and some damages to the metal wiring on the surface after removing the resist film were observed.
TABLE 9
Effect of Two-step Steam Processing for Device
first step
second step
resist removal
steam-
steam-
state
processing
contacting
spraying
[state of metal
step
process
process
wiring]
con-
kind of steam
saturated steam
saturated steam
removed in
dition
removal
containing
no promotion
process time of
promotion
alkali
ingredient
1 min and
ingredient
30 sec
temperature
100° C.
100° C.
[no damage to
of steam
metal wiring]
processing
1 min
30 sec
time
com-
kind of steam
no first step
saturated steam
removed in
pari-
removal
containing
spraying time
son
promotion
alkali
of 2 min
ingredient
temperature
100° C.
[damages to
of steam
metal wiring]
processing
2 min
time
Example 5
Shown are examples by hot steam processes for ion-implanted resist films, which are hard to peel off.
Sample: FIG. 5C; silicon thermal oxidation film etched; its underlayer of a silicon substrate ion-implanted;
Ion-implantation conditions: acceleration energy of 80 keV; dose amount of phosphorus of 6×10 13 /cm 2
Result of Peeling:
Table 10 shows the results.
In the 100° C. saturated steam process of the condition 1, the resist film could not be removed even by spraying for ten minutes.
In the 120° C. saturated steam process of the condition 2, the resist film could be removed by contacting process for two minutes and spraying process for one minute.
In the 140° C. superheated steam process after the 130° C. saturated steam process for thirty seconds of the condition 3 , the resist film could be removed by spraying process for thirty seconds.
A quality-change effect by hot saturated steam and a peeling effect by superheated steam at a high temperature were confirmed.
TABLE 10
Effect of High-temperature Superheated Steam for Ion-
implanted Resist Removal
first step
second step
processing
steam-contacting
steam-spraying
resist removal
step
process
process
result
con-
kind of
no first step
saturated steam
could not be
dition
steam
removed by
1
temperature
100° C.
spraying for
of steam
10 min
processing
10 min
time
con-
kind of
saturated steam
saturated steam
removed in
dition
steam
processing
2
temperature
120° C.
120° C.
time of
of steam
3 min
processing
2 min
1 min
time
con-
kind of
saturated steam
superheated steam
removed in
dition
steam
processing
3
temperature
130° C.
140° C.
time of
of steam
1 min
processing
30 sec
30 sec
time
Example 6
Shown are examples by combinations of steam and ultraviolet processes for ion-implanted resist films, which are hard to peel off.
Ultraviolet lamp: KrI excimer lamp, wavelength; 191 nm;
Ultraviolet irradiation quantity: 10 mW/cm 2 (surface to be processed).
Result of Peeling:
Table 11 shows the results.
After the 100° C. saturated steam process and the ultraviolet irradiation process for two minutes of the condition 1, the resist film could be removed by spraying process for one minute.
After the 120° C. saturated steam process and the ultraviolet irradiation process for thirty seconds of the condition 2 , the resist film could be removed by spraying process for thirty seconds.
TABLE 11
Effect of Ultraviolet Irradiation Superimposition for
Ion-implanted Resist Removal
first step
steam-contacting
process
ultraviolet
second step
resist
processing
irradiation
steam-spraying
removal
step
superimposition
process
state
con-
kind of
saturated steam
saturated steam
removed in
dition
steam
processing
1
temperature
100° C.
100° C.
time of
of steam
3 min
processing
2 min
1 min
time
con-
kind of
saturated steam
superheated steam
removed in
dition
steam
processing
2
temperature
120° C.
130° C.
time of
of steam
1 min
processing
30 sec
30 sec
time
Example 7
Shown are examples by a sequential process of resist-peeling and surface-cleaning after peeling.
Ultraviolet lamp: KrI excimer lamp, wavelength; 191 nm;
Ultraviolet irradiation quantity: 10 mW/cm 2 (surface to be processed).
Resist-peeling Step:
Saturated steam at temperatures to meet various resist processes was used. Resist-peeling is performed by the first step of steam-contacting and the second step of steam-spraying with combining ultraviolet irradiation.
Cleaning Step:
Steams containing chemicals are generated by supplying the chemicals one after another through a cleaning liquid supply line. First, saturated steam containing fluoric acid and hydrogen peroxide is sprayed onto a substrate surface to remove metal and organic matters. At this time, particles are removed by the spraying power of a steam mist. Next, saturated steam containing diluted fluoric acid is sprayed onto the substrate surface. For example, the silicon surface of a contact hole in the substrate becomes bare silicon. Finally, steam of pure water is sprayed to wash. Such a chemical prescription is selected in accordance with the object of the process.
Drying Step:
Because superheated steam contains no mist, rapidly drying can be performed. Ultraviolet irradiation combined performs completion of surface-cleaning as well as a promotion of drying.
Result of Peeling:
Both the resist removal and the surface-cleaning were completely performed.
TABLE 12
Making Resist-peeling Process and Surface-cleaning
Process after Peeling Sequential
first/second
cleaning
drying
step
step
step
steam
steam
steam
processing
processing
processing
ultraviolet
ultraviolet
ultraviolet
irradiation
irradiation
irradiation
processing
super
super
super
step
imposition
imposition
imposition
kind of
saturated
steam
steam
temperature
100 to 140° C.
of steam
processing
according to
time
each resist
kind of
saturated
steam
steam
temperature
100 to 140° C.
of steam
kind of
fluoric acid/
dil.
pure
cleaning
hydrogen
fluoric
water
liquid
peroxide
acid
cleaning
15 sec
15 sec
10 sec
time
kind of
superheated
steam
steam
temperature
120 to 140° C.
of steam
drying time
10 sec
nitrogen
10 sec
introduction
time
Various Embodiments According to Other Aspects of the Present Invention
As described above, the present inventors have realized techniques of peeling resist films with steam, besides, they have established techniques for combining them with promotion effects by chemical ingredients and effects by ultraviolet irradiation.
Additionally, the present inventors now propose techniques to make the peeling-off operation more sure and rapid by closely cross-combining applications of peeling actions, i.e., operations of peeling mechanisms, in relation to timely and spatial conditions, temperature conditions, and physicochemical conditions. That is, the present inventors grasp the peeling techniques from a new viewpoint that the properly cross-combining manners of the above conditions are considered, and make it possible to realize the techniques for this purpose and grasp them practically.
1. Cross-Combination of Process Conditions
In general, process conditions are mostly set in a stationary state. However, peeling a film is a phenomenon of a break of a stationary state, i.e., an adhering state. Therefore, peeling is a non-stationary phenomenon essentially. For example, a resist film is hydrated and swelled by an effect of steam, but it is never peeled off only by keeping the physicochemical state. A physical action, i.e., spraying, is required for peeling the film. Thus the peeling process requires a non-stationary cross-combination of various conditions.
Proper cross-combination is not a mere combination of different conditions. Proper cross-combination is an arrangement of conditions on the premise of an estimate and grasp of means and results. In detail, it includes interception condition design, inversion condition design, variation condition design, etc. A proper cross-combination of such process conditions produces an effect.
In particular, the following is the most principal reason why peeling techniques for resist films require such a proper cross-combination of process conditions. There is an untouchable ground that protection of the minute structure of the exposed surface after peeling must be ensured. In a peeling process, the surface of the resist film and the surface of the minute structure coexist temporarily. Conditions effective for peeling may cause damages on the minute structure surface. For reconciling peeling and protection of the minute structure surface, a proper cross-combination of process conditions is necessary.
2. Specific Modes of Proper Cross-Combinations of Process Conditions
(1) Modes of Timely and Spatially Proper Cross-Combinations
In modes of timely cross-combinations, for example, the order of operations of two conditions or mechanisms A and B is set at A→B, A←B, or A and B at once, and an operation time is set to either of A and B.
Modes of spatially proper cross-combinations include, e.g., cases of processing the whole surfaces, one surface, and a partial surface.
(2) Modes of Proper Cross-Combinations on Temperature
The portions to be heated and/or cooled are selected to the whole surfaces, one surface, or a partial surface to be processed. For example, a combination of one surface heating and one surface cooling is made. Preheating or rapid heating, or pre-cooling or rapid cooling is selected. Also possible are modes in which cross-combinations on temperature are further cross-combined timely or spatially.
(3) Modes of Physicochemically Proper Cross-Combinations
These modes include combinations on composition and combinations on concentration of chemical ingredients, and timely and spatially proper cross-combinations of applications of chemical ingredients. Irradiation with high frequency supersonic waves or ultraviolet rays may be combined.
The above modes ( 1 ), ( 2 ), and ( 3 ) can be properly cross-combined with one another.
3. Specific Examples of Proper Cross-Combinations of Process Conditions
Specific examples of proper cross-combinations will be described below, though the present invention is not limited to those examples.
(1) Cross-Combination of Steam-Contact and Steam-Spraying (Timely Cross-Combination)
A certain time is required for a resist film to be swelled and hydrated by a chemical action. For this process, suitable is a process of stationary contact with steam. After the resist film has changed in its quality due to the steam, spraying power of steam is required. That is, a steam-contact process and a steam-spraying process should be combined at a time interval.
A specific example of this mode is the above example 4, which is a proper cross-combination of a steam-contact process, a steam-spraying process, and alkali.
(2) Cross-Combination of Saturated Steam Process and Superheated Steam Process (Timely and Physicochemically Proper Cross-Combination and Proper Cross-Combination on Temperature)
Saturated steam gives wetting conditions, and superheated steam gives hot drying conditions. For example, a 100° C. saturated steam process and a 100° C. saturated-150° C. superheated steam process are properly cross-combined. In the 100° C. saturated steam process, swelling and hydration of a resist film progress. In the 100° C. saturated-150° C. superheated steam process, the adhesion boundary of the resist film is dried, and this causes peeling at the boundary. Thus effective is a combination of the 100° C. saturated steam process and the 100° C. saturated-150° C. superheated steam process at a proper time interval.
Besides, a superheated steam process can be effectively used for drying after peeling and washing.
A specific example of this mode is the above example 5, which is a proper cross-combination of saturated and superheated steams.
(3) Cross-Combination of Steam Process and Chemical Ingredient-Containing Steam Process (Physicochemically and Timely Proper Cross-Combination)
It has been confirmed that a change in quality of a resist film is accelerated by steam containing a chemical ingredient. For example, steam containing an alkali ingredient can rapidly peel a resist film. However, if the underlayer is a minute structure of, e.g., a metal wiring surface, the wiring material such as aluminum or copper (in particular, aluminum) is etched and damaged by alkali. In this case, by using steam containing a certain kind of surface active agent, chemical damage on aluminum can be reduced to the extent that is usually negligible.
Specific examples of this mode are the above examples 2 and 3, which are proper cross-combinations of alkali and hydrogen peroxide.
(4) Cross-Combination of Steam Process and Isopropyl Alcohol (IPA) Vapor Process
A resist-peeling effect of an IPA-water-salt base peeling liquid is known. Gas-liquid interface action of IPA is well-known as Marangoni effect. The present inventors have found that IPA vapor shows an resist-peeling promotion effect in an atmosphere of steam. Since IPA is an organic chemical ingredient which never acts on a surface material, it can be used without any damage on a metal wiring surface.
Cross-Combination Mode 1 : (timely and Physicochemically proper Cross-combination)
A steam process and an IPA vapor process are timely cross-combined.
Cross-Combination Mode 2 : (Physicochemically Proper Cross-combination)
An IPA vapor process, i.e., a composition of chemical ingredient is cross-combined.
Example 8
Effects of cross-combinations of IPA vapor processes in steam processes were examined in relation to various kinds of resist films.
By cross-combined process conditions shown in the below table 13, resist-peeling could be performed in one to two minutes.
TABLE 13
Cross-Combination with IPA Vapor Process
resist
time
removal
combined processes
distribution
time
cross-
first step: steam process
0.4
1-2 min
combination
second step: IPA vapor process
0.2
mode 1
third step: steam process
0.4
cross-
IPA-containing steam process
—
1-2 min
combination
mode 2
time distribution: ratio of each process time to the whole process time
IPA-containing steam: IPA/steam=0.1/1.0 (volume ratio)
steam: 120° C. saturated steam, 2.5-5 L/sec (substrate spinning)
(5) Cross-Combination of Steam Process and Water-spraying Process and Application of High-frequency Supersonic Waves
There are resist films which can fully be peeled off by the spraying power of steam after a steam process, and resist films which require certain times for being peeled off only by the spraying power of steam. In the latter case, a cross-combination of a water-spraying process is effective. When the sprayed quantities are the same, the collision power of water is greater than that of steam in proportion to the difference in mass by about three figures. Besides, the resist which has been softened at the temperature of steam, is cooled by sprayed water to be hardened. This serves as an additional peeling action.
Highly compressed water, i.e., a jet water stream is used for cutting a silicon wafer or as a surgical knife. Spraying compressed water can peel any stable film, but protection of the surface to be minutely processed, from being damaged, must be fully ensured. Therefore, important is design of the linear velocity of sprayed water, for relieving pressure and sprayed quantity, i.e., for protection of minute structure.
Cross-Combination Mode 1: (Timely and Physicochemically Proper Cross-combination)
A water-spraying process at a relieved pressure is performed after a steam-contact process. Obtained is a united effect of a pyrogenetic chemical reaction of steam and a cooling action of compressed water.
Cross-Combination Mode 2 : (Spatially Proper Cross-combination and Proper Cross-combination on Temperature)
In spinning a surface, a steam-spraying process is performed on one side, and a water-spraying process is performed on the other side. Vibration of temperature is thereby applied to the surface in a cycle of heating and cooling in accordance with the spinning speed. Also in this cross-combination mode, the same peeling effect as the above can be obtained.
Cross-Combination Mode 3 : (Physicochemically Proper Cross-Combination)
In one of the above cross-combination modes 1 and 2 , the water-spraying process is performed using a high-frequency supersonic nozzle. Because the spraying energy and the supersonic energy are summed to increase the peeling power, the process is performed under conditions by which each energy is relieved in order to ensure the protection of the target minute circuit structure.
Example 9
Effects of cross-combinations of steam processes and water-spraying processes and applications of high-frequency supersonic waves were examined in relation to various kinds of resist films. By cross-combined process conditions shown in the below table 14, resist-peeling could be performed in one to two minutes.
TABLE 14
Cross-Combination with Water spraying Process and High-
frequency Supersonic Process
time
resist
combined process
distribution
removal time
cross-
first step: steam contact
0.5
1-2 min
combination
second step: water spraying
0.5
mode 1
cross-
one surface steam spraying
simultaneous
1-2 min
combination
one surface water spraying
simultaneous
mode 2
cross-
one surface steam spraying
simultaneous
1-2 min
combination
one surface water spraying
simultaneous
mode 3
with applying high-frequency
supersonic
steam: 120° C. saturated steam, 2.5-5 L/sec (substrate spinning)
(6) Cross-Combination of Steam Process and Compressed Carbonic Acid Gas-spraying Process
This cross-combination produces a special effect in addition to the effect of cooling and hardening in the cross-combination of the above water-spraying process.
The temperature of fine dry ice particles generated by spraying compressed carbonic acid gas, is −55° C. Moisture which has permeated into the adhesion boundary in the steam process, momentarily crystallizes and expands by spraying carbonic acid gas. This freezing of the moisture brings about an effect of ice columns, and serves as a strong additional peeling power.
Cross-Combination Mode 1 : (Timely and Physicochemically Proper Cross-combination and Proper Cross-combination on Temperature)
By alternately repeating a steam process and a compressed carbonic acid gas-spraying process, obtained is a peeling effect by temperature vibration of heating and cooling. This is because the coefficient of expansion varies in accordance with the kind of material. For example, the linear expansion coefficient of silicon is 0.076×10 −4 /K, while those of many organic materials are 2.2 to 5.0×10 −4 /K. There is a difference by about one to two figures. The difference in linear expansion coefficient between a silicon substrate and a resist film brings about a peeling power at the boundary by the temperature amplitude of about 150° C.
Cross-Combination Mode 2 : (Spatially and Physicochemically Proper Cross-combination and Proper Cross-combination on Temperature)
In spinning a surface, a steam-spraying process is performed on one side, and a compressed carbonic acid gas-spraying process is performed on the other side. Vibration of temperature is thereby-applied to the surface in a cycle of heating and cooling in accordance with the spinning speed. Also in this cross-combination mode, the same peeling effect as the above can be obtained.
Cross-Combination Mode 3 : (Spatially and Physicochemically Proper Cross-combination and Proper Cross-combination on Temperature)
A steam-spraying process is performed onto the resist-side surface of a substrate, and a compressed carbonic acid gas-spraying process is performed onto the opposite surface of the substrate. A difference in temperature is thereby made between the resist film and the substrate at their boundary. Also in this cross-combination mode, the same peeling effect as the above can be obtained.
Example 10
Effects of cross-combinations of steam processes and compressed carbonic acid gas-spraying processes were examined in relation to various kinds of resist films. By cross-combined process conditions shown in the below table 15, resist-peeling could be performed in one to two minutes.
TABLE 15
Cross-Combination with Compressed Carbonic Acid Gas
spraying Process
resist
time
removal
combined process
distribution
time
cross-
steam spraying 5 sec/process
alternate
1-2 min
combination
CO 2 gas spraying 5 sec/process
alternate
mode 1
cross-
one surface steam spraying
simultaneous
1-2 min
combination
one surface CO 2 gas spraying
simultaneous
mode 2
cross-
front surface steam spraying
simultaneous
1-2 min
combination
back surface CO 2 gas spraying
simultaneous
mode 3
steam: 120° C. saturated steam, 2.5-5 L/sec (substrate spinning)
(7) Cross-Combination of Steam Process and Substrate Cooling Process (Proper Cross-combination on Temperature)
The resist-side surface of a substrate is processed by steam with supporting the substrate on a cooling plate. The cooling plate may perform cooling by any of an electronic cooling method using a Peltier element, a fluoric oil coolant circulation method, and a ventilation cooling method by spraying compressed carbonic acid gas.
Obtained are the same united effect and peeling action as those by cooling by the above water- or compressed carbonic acid gas-spraying process.
Example 11
Effects of cooling substrates in steam processes were examined in relation to various kinds of resist films. The cross-combination order of a steam-spraying process and a substrate cooling process and the process time of each of them vary in accordance with the kind of resist, so conditions to obtain greater effects are selected. The below table 16 shows examples of such conditions. By the conditions shown, resist-peeling could be performed in one to two minutes.
TABLE 16
Cross-Combination with Substrate Cooling Process
time
resist
combined process
distribution
removal time
cross-
substrate cooling step
0.5
1-2 min
combination
steam spraying step
0.5
mode 1
cross-
front surface steam spraying
0.5
1-2 min
combination
(120° C. saturated)
mode 2
back surface cooling
0.5
steam: 120° C. saturated steam, 2.5-5 L/sec (substrate spinning)
substrate cooling: Peltier element electronic cooling method, substrate temperature: −10° C.
(8) Cross-Combination of Steam Process and Ultraviolet Irradiation Process (Physicochemically Proper Cross-combination)
In case of combination with a steam process, used are ultraviolet rays whose 50% transmissive distance to steam is 2 mm or more. A combination with a superheated steam process is effective. Since superheated steam contains no mist, scattering loss of ultraviolet rays is little. A light quantity and an irradiation time of ultraviolet rays suffice if they bring about a change in quality of the adhering surface of a resist film by a photochemical action.
A specific example of this mode is the above example 6, which is a proper cross-combination of steam and ultraviolet rays.
(9) Cross-Combination of High-pressure Carbonic Acid Gas Process and Ultraviolet Irradiation Process (Physicochemically Proper Cross-Combination)
In an atmosphere of carbonic acid gas, even short-wavelength ultraviolet rays whose 50% transmissive distance to steam is less than 2 mm, can be used with a high transmissivity. The transmissive distance of ultraviolet rays of the wavelength of 172 nm is about 30 cm. That is, a Xe excimer lamp (wavelength: 172 nm) can be used. This is effective to decompose and remove fine resist pieces which have remained within fine gaps of the structure after peeling a resist film.
Example 12
In case of processes of peeling resist films off device surfaces having minute structural patterns, after which processes fine resist pieces remain at the corners of the patterns and within gaps of wiring patterns, decomposing and removing processes for the remaining resist pieces were performed by ultraviolet irradiation processes.
Surfaces to be processed were irradiated by a Xe excimer lamp with spraying carbonic acid gas onto the surfaces. The below table 17 shows the results.
TABLE 17
Ultraviolet Irradiation Process for Remaining Resist
Pieces
surface
resist remaining
ultraviolet
SEM inspection after process
state
irradiation time
remaining resist
remaining a little in
10-20 sec
could not detect
minute pattern gaps
resist residues
about 1 min
could not detect
scattered
Xe excimer lamp: irradiation quantity 20 mW/cm 2 (substrate spinning)
(10) Cross-Combination with Cleaning Process
The purification level of the surface which a resist film has been peeled off, or the purification level of the surface required in the subsequent process varies in accordance with the process in question. Therefore required is a system in which proper cross-combinations of steam conditions and a cross-combination of ultraviolet irradiation can easily be set.
A specific example of this mode is the above example 6, which is a cross-combination with a cleaning process.
4. Resist Film Removing Apparatus
A specific example of resist film removing apparatus wherein cross-combination modes of various processes (means) are taken into consideration, will be described.
FIG. 6 is a schematic sectional view of a one-by-one resist film removing apparatus including a spinning mechanism.
This resist film removing apparatus is provided with a chamber having a substrate taking-in/out system, an atmosphere purge system, and a discharge system. In the chamber, in addition to a system for introducing steam, provided is at least one of systems for respectively introducing IPA vapor, water, and compressed carbonic acid gas; a system for adding a chemical ingredient to the above steam or water; systems for respectively performing irradiation with ultraviolet rays and high-frequency supersonic waves; and a system for heating and cooling substrates. A driving system is provided for moving each spraying nozzle relatively to the front or back surface of a substrate so as to sweep the surface.
A spinning mechanism is provided in the steam process chamber 101 . The spinning mechanism comprises a rotor 104 provided with support pins 103 for fixing a substrate 102 , and a hollow cylindrical motor 105 .
As a substrate cooling system, a cooling plate 106 is supported by a supporting mechanism fixed in the motor 105 .
As an ultraviolet irradiation system, a lamp chamber 110 including an ultraviolet lamp 108 and having a quartz window board 109 is disposed on the upper part of the steam process chamber 101 . FIG. 6 shows a cross section of the ultraviolet lamp 108 .
As systems for respectively introducing steam, water, IPA vapor, and compressed carbonic acid gas, the steam process chamber 101 is provided with a steam inlet 111 and a steam spraying nozzle 112 , a water spraying nozzle 113 , an IPA vapor spraying nozzle 114 , and a compressed carbonic acid gas spraying nozzle 115 . A rear side nozzle 116 for compressed carbonic acid gas is used for cooling the substrate 102 in place of the cooling plate 106 .
As a high-frequency supersonic irradiation system, the water spraying nozzle 113 is provided with a high-frequency supersonic oscillator 117 . The shape of each spraying nozzle is schematically shown in FIG. 6 .
The steam process chamber 101 is further provided with an atmosphere purge gas inlet 118 and a discharge system 119 .
As a system for adding a chemical ingredient to steam or water, a chemical injecting device 122 comprising a fixed flow rate pump is connected to an ultrapure water supply line 121 for a steam generator 120 and the water spraying nozzle 113 .
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A line slit nozzle for spraying steam is disposed along a diameter of a resist film. Steam containing a mist is sprayed onto a surface of the resist film. The film is thereby peeled off and removed. By using a change in physical properties (swelling, etc.) of the resist film by water, the film is easily and surely peeled off. Breakaway from much resources/energy consumption type techniques is realized. In other words, realized are environment-symbiosis type techniques by which resist films can be removed independently of the quantity of energy and kinds of chemical solvents.
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BACKGROUND OF THE INVENTION
This invention relates to vacuum degassing apparatus and more particularly to a vacuum degassing installation having plural vacuum degassing vessels and which is capable of continuous operation.
One type of vacuum degassing vessel includes one or more downwardly projecting nozzles for drawing metal contained in a ladle upwardly into the vessel for degasification. The lower end of the nozzle is submerged beneath the level of metal in the ladle whereby the metal is drawn at least partway into the vessel as the result of the vacuum therein. In two nozzle vessels, additional metal is conveyed upwardly through a first nozzle by some additional agencies such as a gas lift or an electromagnetic pump. The degassed metal then flows back to the ladle through the second nozzle. Examples of two nozzle vessels are shown in U.S. Pat. Nos. 2,893,860 and 2,994,602.
In single nozzle vessels, metal is moved into and out of the vacuum degassing vessel by cyclically lowering and elevating the same relative to the metal contained with the ladle. Metal is forced into the vessel when there is relative movement of the ladle and vessel toward each other and discharged when separation of the two is increased. An example of a single nozzle vessel is shown in U.S. Pat. No. 2,967,768.
In order to exclude slag which normally covers the molten metal in the ladle, slag shields or breakers are usually affixed to the lower ends of each nozzle between each successive treating cycle. These shields consist of conical shields of about the same composition as the metal being processed. As the lower end of the nozzles are submerged into the metal, the shield prevents entry of slag into the nozzle but soon melts to permit the entry of molten metal into the nozzle.
Additional routine maintenance must also be performed on vacuum degassing vessels. For example, with a typical two-nozzle vessel, slag must be removed from the nozzle and routine nozzle maintenance performed after every five heats requiring about forty-five to one hundred minutes. In addition, the nozzles must be replaced about every sixty heats requiring about one hour and twenty-five minutes. About every one hundred twenty heats, the vessel bottom must be replaced requiring about one hour and twenty-five minutes. Finally, about every 2,500 heats, the upper vessel must also be replaced requiring about six to eight hours. Thus, in an average of twenty shifts, a vessel is available for use only about 80% of the time.
Prior art attempts to increase vessel availability involve mounting a pair of vessels on a turntable with one vessel being mounted in an operative position and a second in a repair position. When it is desired to alternate vessels, the turntable is rotated to move one vessel from the operative to the repair position and the vessel previously in operation is moved to the maintenance position. Such a system is shown in U.S. Pat. No. 3,756,584. This arrangement still does not provide 100% vessel availability because of the time required to disconnect the first vessel from the vacuum system to move the first vessel out of the operative position and the second vessel into its place and then to reconnect the vacuum system to the second vessel. In addition, in such prior art systems, it was not possible to test the vacuum connections of the vessel in the repair position.
SUMMARY OF THE INVENTION
It is a primary object of the invention to provide a new and improved vacuum degassing apparatus.
Another object of the invention is to provide a vacuum degassing system which provides substantially continuous operation.
Another object of the invention is to provide a vacuum degassing apparatus having a pair of vessels movable between operative and repair positions wherein it is not necessary to disconnect the vacuum system when the vessel is moved.
A still further object of the invention is to provide a vacuum degassing apparatus having vessels movable between operative and repair positions wherein vacuum testing may be carried out in the repair position.
These and other objects and advantages of the present invention will become more apparent from the detailed description thereof taken with the accompanying drawings.
In general terms, the invention comprises a vacuum degassing apparatus including first and second vessels mounted respectively on first and second support means which are each mounted for independent horizontal movement for transporting the vessels between operative and maintenance positions which are separate from but adjacent to those of the other vessel. Each of the first and second support means are also independently mounted for vertical movement so that each vessel may be lowered toward a ladle disposed therebelow or for maintenance in the repair position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a vacuum degassing apparatus according to the preferred embodiment of the present invention;
FIG. 2 is a plan view of the apparatus illustrated in FIG. 1;
FIG. 3 schematically illustrates one of the vacuum degassing vessels of FIG. 1 in operative position; and
FIG. 4 schematically illustrates the vessels of FIG. 1 in an alternate position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 show the vacuum degassing apparatus of the present invention to include a pair of vacuum degassing vessels 10 and 12 which are each supported by suspension assemblies 13 and 14, respectively, for horizontal and vertical movement on a framework 15 by individual vessel cars 16 and 17. The framework includes a plurality of suitably supported vertical beams 18 of structural steel and a plurality of cross members 19 which extend between the upper end of columns 18 for defining a treatment bay 20 and a maintenance bay 22. The cars 16 and 17 are mounted for rolling movement in a direction normal to the bays 20 and 22 so that each vessel 10 and 12 may be positioned over either bay independently of the other. For purposes of illustration, the vessel 10 is shown in FIG. 1 to be positioned in the treatment bay 20 and the vessel 12 is shown to be disposed in the maintenance bay 22.
Extending below the framework 14 and through the treatment bay 20 is a first pair of rails 24 while second and third pairs of rails 26 and 28 extend through the maintenance bay 22. The rails 24 support a ladle car 30 upon which a ladle 32 is disposed for movement through the treatment bay and rails 26 and 28, respectively, support a nozzle transfer car 34 at ground level and a vessel bottom car 36 at an elevated position relative to the car 34.
When a ladle 32 of hot metal 48 is positioned in bay 20 and below vessel 10, the latter may be lowered for vacuum treatment as will be discussed below. Simultaneously, the vessel 12 may be positioned in the treatment bay 22 for servicing as required. The vessels 10 and 12 are each coupled to a vacuum system (not shown) by a conduit assembly 38 comprising pairs of conduits 40, 42 and 44, 46 which are respectively pivotally connected to each other and to their associated vessels 10 and 12. In this manner, the vacuum connections may be maintained as the vessels 10 and 12 move between the treatment and service positions as well as while they are being raised and lowered.
FIG. 3 shows the vessel 10 in position for treating molten metal 48, such as steel, in a ladle 32. In the illustrated embodiment, the vessel 10 includes an upper, generally cylindrical body portion 50 having a flange 52 at its lower end for being suitably affixed to the flange 54 at the upper end of a cup-shaped bottom portion 56. The upper body portion 54 and the bottom 56 when assembled define a vacuum chamber 58. A pair of spaced apart openings 60 and 61 connect to the lower end of bottom portion 56 and each has a flange 62 surrounding its lower end of the openings 60 and 61, respectively. A vacuum offtake opening 67 is also formed at the upper end of body portion 50 and is coupled to a dust collector and cooler 68 by a conductor 70. The conduit 42 is connected to the upper end of dust collector 68 by a rotary joint 70 to maintain the vacuum connection as the dust collector cooler 68 is raised and lowered along with vessel 10.
The suspension assemblies 13 and 14 and the cars 16 and 17 which support each vessel 10 and 12 are identical and accordingly, only car 16 and its suspension assembly 13 will be discussed in detail. However, the same reference numerals will be used for like components of each car and suspension assembly. Car 16 includes a generally rectangular frame 74 having rollers 78 at each corner and which in turn are mounted on rails 80 supported atop the horizontal frame members 19 at one side of the framework 14. The rails 80 extend generally normally to and span both bays 20 and 22. As seen in FIG. 2, a second pair of rails 84 are disposed on the members 19 at the opposite side of the framework 14 for supporting the car 17.
The suspension assembly 13 carried by car 16 is coupled to a platform 90 upon which the associated vessel 10 is mounted. Platform 90 includes a rectangular base 92 formed of suitable structural steel members which are engaged by brackets 94 affixed to the vessel 10 intermediate its ends. Columns 96 extend vertically from each corner of the base where their upper ends are jointed by cross members 97 to define a generally rectangular upper frame. At each corner of the upper frame is a pulley 100.
The elevation and suspension assembly 13 also includes a drive motor 102 mounted on car 16 and having a pair of drums 104, 105 mounted on its output shaft 107. In addition, there are a first pair of double sheave pulleys 109 and 110 mounted on car 80 for rotation about axes parallel to and adjacent drums 104 and 105, respectively. In addition, there are a second pair of sheaves 112 and 113 mounted for rotation about axes parallel to drums 104 and 105, respectively, but at their remote ends of the car 16. Cables 115 and 116 extend from drums 104 and 105, respectively, and over one sheave of pulleys 109 and 110 from which they pass downwardly and around one of the pulleys 100 and the platform 90 below from which each returns upwardly for attachment to the other sheave of corresponding pulleys 109 and 110. Additionally, cables 118 and 119, respectively, extend from drums 104 and 105 and each similarly couples to one of the pulleys 112 and 113 and to the pulleys 100 at the opposite end of the platform 90.
It will be appreciated that when the motor 102 is driven in a first direction, the platform 90 and the vessel 10 mounted thereon will be elevated while rotation of the motor 102 in the opposite direction will elevate the platform 90 in vessel 10. It will be appreciated that suitable limit switches may be provided for limiting the upward and downward movement of platform 90 to preselected limits.
A second motor 120 mounted on car 16 is coupled to one of the rollers 78 for driving car 16 along the rails 80 and between the treatment and service positions. In addition, suitable limit switches are provided to limit the rolling movement of car 16 while suitable stops 122 at the end of each rail are provided as a safety precaution. As indicated above, the car 16 and the car 17 are transported and positioned in an identical manner.
The conduit system 38 includes a first pipe 124 connected to the vacuum system (not shown) and to the midpoint of a second conduit 126 (FIG. 2) extending along the rear of the assembly. One end of conduit 126 is connected by a first rotary joint 128 to the lower end of conduit 40 and by a second rotary joint 130 to the lower end of conduit 44. The other end of conduit 40 is connected by a rotary joint 132 to one end of conduit 42, the other end of which is connected by a rotary joint 72 to the cooler collector 68 as indicated above. Similarly, rotary joint 134 couples conduits 44 and 46 to each other and rotary joint 136 couples conduit 46 to the dust trap and cooler 68 associated with vessel 12.
In operation, one of the vessels, such as vessel 10 for example, will be positioned over the treatment bay 20 by its car 16 while the second vessel 12 may be positioned over the service bay 22 by its car 17 as seen in FIG. 1. The ladle 32, which may contain molten ferrous metal from a BOF furnace, for example, is placed upon the car 30 which is then moved into the treatment bay on tracks 24 until the ladle 32 is positioned below vessel 10. The platform 90 is then lowered to immerse the lower end of the nozzles 64 and 65 beneath the surface 48 of the metal within ladle 32 as seen in FIG. 3. The valve 138 at the near end of conduit 126 is opened to couple the interior of vessel 10 to the vacuum system. As the pressure within the chamber 58 is reduced, the differential pressure will cause molten metal to flow from ladle 32 part way up the nozzles 64 and 65. In addition, inert gas such as argon is injected into nozzle 64 thereby reducing the specific gravity of the metal and causing the same to flow into chamber 58 where degasification occurs. The degassed metal having a higher specific gravity then flows downwardly through nozzle 65 for return to ladle 32. In this fashion, molten metal is circulated through the vessel 10 in a known manner until the contents of the ladle 32 have been degassed to the desired degree.
As schematically illustrated in FIG. 3, a layer of slag 140 may flow atop the metal 48. In order to prevent the entry of the slag into the vessel 10, slag breakers 142, as shown by broken lines in FIG. 3, are affixed at the lower end of each of the nozzles 64 and 65. Once submerged into the metal 48 the slag breakers will dissolve. Accordingly, it is necessary to affix such slag breakers to the nozzles between each treatment.
When the system according to the invention is employed with a BOF vessel, treatment cycles occur about every 48 minutes. In other words, hot metal will be tapped from the BOF vessel at about that frequency rate. The vacuum treatment will typically require about 30 minutes while about 15 minutes are required for the attachment of slag breakers. Thus, one vessel could conceivably service a BOF vessel on a continuous basis of other maintenance requirements were disregarded. However, in order to prolong the life of the nozzles, it is generally required that they be allowed to cool between operations. The cooling and attachment of slag breakers normally requires about 55 minutes, with two vessels working alternately, the nozzles of one vessel can be cooled and slag breakers attached while the other vessel is treating a ladle of molten metal. Thus, while the vessel 10 is treating a ladle of molten metal, the nozzles of vessel 12 are being cooled after which slag breakers are attached. After completion of the degasification of the metal within the ladel 32 by vessel 10, the latter is elevated by its elevating mechanism 76 after which it is transported by its car 16 over the maintenance bay 22. Simultaneously, the vessel 18 which has just been serviced may be transported to the treatment bay 20 in preparation for a second ladle of molten metal. When the second ladle 32 is positioned beneath vessel 12, the latter is lowered into its treatment position while the vessel 10 is cooling and otherwise being serviced.
The tandem array of vessels also permits longer maintenance procedures. For example, about once every five treatment cycles, it is necessary for more extensive nozzle repair which may take as much as one and one-half hours. Under these circumstances, the other vessel will be used in two consecutive heats, thus permitting substantially continuous utilization. Also, approximately every 60 heats the nozzles must be exchanged by disengaging the nozzles from flanges 62, for example. This procedure requires about one and one-half hours and again, while the snorkels are being replaced on one vessel, the other vessel is operated on successive sheaths. Finally, major procedures such as replacement of vessel bottoms and the like can be accomplished during periods when the BOF vessel is also being serviced.
It can thus be seen, that the apparatus according to the present invention allows substantially continuous degassing of molten metal as the same is brought from a BOF vessel at intervals of about forty-five minutes. This is true regardless of the fact that the degassing vessels and particularly the nozzles require periodic cooling and maintenance at intervals much more frequent than that required by the BOF vessel.
While the invention has been illustrated and described in relation to a two nozzle vessel, it will be appreciated that it also has application to single nozzle vessels as well. In that case each of the vessels 10 and 12 would be replaced by a single nozzle vessel which would be operated in the manner discussed in U.S. Pat. No. 2,967,768. Otherwise, movement of the vessels between operation and maintenance positions would be identical to that discussed above.
Accordingly, while only a single embodiment of the invention has been illustrated and described, it is intended to be limited thereby but only by the scope of the appended claims.
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A vacuum degassing apparatus has first and second degassing vessels each separately mounted for independent horizontal movement from a first operative position to a second repair position. In addition, each vessel is independently mounted for vertical movement in each position so that a pair of nozzles extending from its lower end to be immersed into a ladle of hot metal when the vessel is at its operative position whereby a degassing operation may be performed. Also, when the vessel is in its repair position, it may be lowered to permit repair or replacement of the nozzles or the vessel bottom as may be required. A vacuum conduit is pivotally connected to each vessel and to a fixed vacuum conduit to maintain the vacuum connection while the vessel is being moved into and out of its various positions.
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FIELD OF THE INVENTION
[0001] This invention relates generally to novel 5-substituted-3-(4-OR 1 -phenyl)-2H-indeno[1,2-c]pyrazol-4-ones which are useful as cyclin dependent kinase (cdk) inhibitors, pharmaceutical compositions comprising the same, methods for using the same for treating proliferative diseases, and intermediates and processes for making the same.
BACKGROUND OF THE INVENTION
[0002] One of the most important and fundamental processes in biology is the division of cells mediated by the cell cycle. This process ensures the controlled production of subsequent generations of cells with defined biological function. It is a highly regulated phenomenon and responds to a diverse set of cellular signals both within the cell and from external sources. A complex network of tumor promoting and suppressing gene products are key components of this cellular signaling process. Overexpression of the tumor promoting components or the subsequent loss of the tumor suppressing products will lead to unregulated cellular proliferation and the generation of tumors (Pardee, Science 246:603-608, 1989).
[0003] Cyclin dependent kinases (cdks) play a key role in regulating the cell cycle machinery. Cdk complexes consist of two components: r a catalytic subunit (the kinase) and a regulatory subunit (the cyclin). To date, nine kinase subunits (cdk 1-9) have been identified along with several regulatory subunits (cyclins A-H)(A. M. Senderowicz and E. A. Sausville Journal of the National Cancer Institute (2000), 92 (5), 376-387; and S. Mani; C. Wang; K. Wu; R. Francis; R. Pestell Exp. Opin. Invest. Drugs (2000) 9(8), 1849-1870). Each kinase associates with a specific regulatory partner and together make up the active catalytic moiety. Each transition of the cell cycle is regulated by a particular cdk complex: G1/S by cdk2/cyclin E, cdk4/cyclin D1 and cdk6/cyclinD2; S/G2 by cdk2/cyclin A and cdk1/cyclin A; G2/M by cdk1/B. The coordinated activity of these kinases guides the individual cells through the replication process and ensures the vitality of each subsequent generation (Sherr, Cell 73:1059-1065, 1993; Draetta, Trends Biochem. Sci. 15:378-382, 1990)
[0004] An increasing body of evidence has shown a link between tumor development and cdk related malfunctions. Over expression of the cyclin regulatory proteins and subsequent kinase hyperactivity have been linked to several types of cancers (Jiang, Proc. Natl. Acad. Sci. USA 90:9026-9030, 1993; Wang, Nature 343:555-557, 1990). More recently, endogenous, highly specific protein inhibitors of cdks were found to have a major effect on cellular proliferation (Kamb et al, Science 264:436-440, 1994; Beach, Nature 336:701-704, 1993). These inhibitors include p16 INK4 (an inhibitor of cdk4/D1), p21 CIP1 (a general cdk inhibitor), and p27 KIP1 (a specific cdk2/E inhibitor). A recent crystal structure of p27 bound to cdk2/A revealed how these proteins effectively inhibit the kinase activity through multiple interactions with the cdk complex (Pavletich, Nature 382:325-331, 1996). These proteins help to regulate the cell cycle through specific interactions with their corresponding cdk complexes. Cells deficient in these inhibitors are prone to unregulated growth and tumor formation.
[0005] Protein kinases, in particular, cdk, play a role in the regulation of cellular proliferation. Therefore, cdk inhibitors can be useful in the treatment of cell proliferative disorders such as cancer, familial adenomatosis polyposis, neuro-fibromatosis, psoriasis, fungal infections, endotoxic shock, trasplantaion rejection, vascular smooth cell proliferation associated with atherosclerosis, pulmonary fibrosis, arthritis glomerulonephritis and post-surgical stenosis and restenosis (U.S. Pat. No. 6,114,365). Cdks are also known to play a role in apoptosis. Therefore cdk inhibitors, could be useful in the treatment of cancer; viral infections, for example, herpevirus, poxvirus, Epstein-Barr virus, Sindbis virus and adenovirus; prevention of AIDS development in HIV-infected individuals; autoimmune diseases, for example, systemic lupus, erythematosus, autoimmune mediated glomerulonephritis, rheumatoid arthritis, psoriasis, inflammatory bowel disease, and autoimmune diabetes mellitus; neurodegenerative disorders, for example, Alzheimer's disease, AIDS-related dementia, Parkinson's disease, amyotrophic lateral sclerosis, retinitis pigmentosa, spinal muscular atrophy and cerebellar degeneration; myelodysplastic syndromes, aplastic anemia, ischemic injury associated with myocardial infarctions, stroke and reperfusion injury, arrhythmia, atherosclerosis, toxin-induced or alcohol related liver diseases, hematological diseases, for example, chronic anemia and aplastic anemia; degenerative diseases of the musculoskeletal system, for example, osteoporosis and arthritis, aspirin-sensitive rhinosinusitis, cystic fibrosis, multiple sclerosis, kidney diseases and cancer pain (U.S. Pat. No. 6,107,305).
[0006] It has also been discovered that some cyclin-dependent kinase inhibitors can be used in combination therapy with some other anticancer agents. For example, the cytotoxic activity of the cyclin-dependent kinase inhibitor, flavopiridol, has been used with other anticancer agents in cancer combination therapy. (Cancer Research, 57, 3375 (1997)).
[0007] Also, it has recently been disclosed that cdk inhibitors may be useful in the chemoprevention of cancer. Chemoprevention is defined as inhibiting the development of invasive cancer by either blocking the initiating mutagenic event or by blocking the progression of pre-malignant cells that have already suffered an insult or inhibiting tumor relapse (U.S. Pat. No. 6,107,305).
[0008] It has recently been discovered that cdk5 is involved in the phosphorylation of tau protein, and therefore cdk inhibitors may be useful in the treatment of Alzheimer's disease (J. Biochem., 117, 741-749, 1995).
[0009] This body of evidence has led to an intense search for small molecule inhibitors of the cdk family as an approach to cancer chemotherapy.
[0010] A series of indeno[1,2-c]pyrazoles having anticancer activity are described in JP 60130521 and JP 62099361 with the following generic structure:
[0011] A series of indeno[1,2-c]pyrazoles having herbicidal activity are described in GB 2223946 with the following generic structure:
[0012] A series of 1-(6′-substituted-4′-methylquinol-2′-yl)-3-methylindeno[1,2-c]pyrazoles having CNS activity are described by Quraishi, Farmaco 44:753-8, 1989 with the following generic structure:
[0013] There remains a strong unmet need for new cdk inhibitors for use in treating proliferative diseases associated with cdk activity.
SUMMARY OF THE INVENTION
[0014] The present invention describes a novel class of 5-substituted-3-(4-OR 1 -phenyl)-2H-indeno[1,2-c]pyrazol-4-ones or pharmaceutically acceptable salt forms thereof that are potent inhibitors of the class of enzymes known as cyclin dependent kinases, which relate to the catalytic subunits cdk 1-9 and their regulatory subunits know as cyclins A-H.
[0015] The present invention is directed to compounds of formula (I), or pharmaceutically acceptable salts thereof, which act as cyclin dependent kinase inhibitors:
[0016] wherein:
[0017] R 1 is selected from the group consisting of —H and —C 1-4 alkyl;
[0018] R 2 is selected from the group consisting of —C 1-4 alkoxy, —NR 3 R 4 , and —(CH 2 )NR 3 R 4 ;
[0019] R 3 is selected from the group consisting of —H and morpholino;
[0020] R 4 is selected from the group consisting of —H and cyclohexyl
[0021] substituted with —NH 2 ; alternatively, R 3 and R 4 together form a 6-membered heterocycle containing 1 to 2 heteroatoms selected from nitrogen and oxygen wherein said 6-membered heterocycle is substituted with 1 R 5 ; and
[0022] R 5 is selected from the group consisting of —H, —NH 2 , —CH 2 NH 2 , and —CH 2 CH 2 NH 2 .
[0023] The present invention is also directed to a novel method of treating proliferative diseases associated with CDK activity by administering a therapeutically effective amount of one of the compounds of the present invention or a pharmaceutically acceptable salt form thereof to a patient in need of such therapy.
[0024] The present invention also relates to a novel method of treating cancer associated with CDK activity by administering a therapeutically effective amount of one of the compounds of the invention or a pharmaceutically acceptable salt form thereof.
[0025] A novel method of treating a proliferative disease, which comprises administering a therapeutically effective combination of one of the compounds of the present invention in combination with one or more other known anti-cancer treatments such as radiation therapy, chemotoxic or chemostatic agents is also dislosed.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Compounds of the present invention have formula (I), or pharmaceutically acceptable salts thereof, which act as cyclin dependent kinase inhibitors:
[0027] wherein
[0028] R 1 is selected from the group consisting of —H and —C 1-4 alkyl;
[0029] R 2 is selected from the group consisting of —C 1-4 alkoxy, —NR 3 R 4 , and —(CH 2 )NR 3 R 4 ;
[0030] R 3 is selected from the group consisting of —H and morpholino;
[0031] R 4 is selected from the group consisting of —H and cyclohexyl
[0032] substituted with —NH 2 ; alternatively, R 3 and R 4 together form a 6-membered heterocycle containing 1 to 2 heteroatoms selected from nitrogen and oxygen wherein said 6-membered heterocycle is substituted with 1 R 5 ; and
[0033] R 5 is selected from the group consisting of —H, —NH 2 , —CH 2 NH 2 , and —CH 2 CH 2 NH 2 .
[0034] As used above, and throughout the description of the invention, the following terms, unless otherwise indicated, shall be understood to have the following meaning. The term “compounds of the invention”, and equivalent expressions, are meant to embrace compounds of formula (I), and includes prodrugs, pharmaceutically acceptable salts, and solvates, e.g. hydrates. Similarly, reference to intermediates, whether or not they themselves are claimed, is meant to embrace their salts, and solvates, where the context so permits.
[0035] The term “derivative” means a chemically modified compound wherein the modification is considered routine by the ordinary skilled chemist, such as an ester or an amide of an acid, protecting groups, such as a benzyl group for an alcohol or thiol, and tert-butoxycarbonyl group for an amine.
[0036] The term “analogue” means a compound which comprises a chemically modified form of a specific compound or class thereof, and which maintains the pharmaceutical and/or pharmacological activities characteristic of said compound or class.
[0037] The term “solvate” means a physical association of a compound of this invention with one or more solvent molecules. This physical association includes hydrogen bonding. In certain instances the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. “Solvate” encompasses both solution-phase and isolable solvates. Exemplary solvates include hydrates, ethanolates, methanolates, and the like.
[0038] The term “effective amount” means an amount of a compound/composition according to the present invention effective in producing the desired therapeutic effect. The term “patient” includes both human and other mammals. The term “pharmaceutical composition” means a composition comprising a compound of formula (I) in combination with at least one additional pharmaceutical adjuvant, excipient, vehicle and/or carrier component pharmaceutically acceptable, such as diluents, preserving agents, fillers, flow regulating agents, disintegrating agents, wetting agents, emulsifying agents, suspending agents, sweetening agents, flavoring agents, perfuming agents, antibacterial agents, antifungal agents, lubricating agents and dispensing agents, depending on the nature of the mode of administration and dosage forms. Any ingredient listed in Remington's Pharmaceutical Sciences, 18 th ed., Mack Publishing Company, may be used.
[0039] The term “alkyl” is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms. Examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, and t-butyl.
[0040] The term “alkoxy” is intended to represent an alkyl group with the indicated number of carbon atoms attached to an oxygen atom. Examples of alkoxy include, but are not limited to, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, s-butoxy, and t-butoxy.
[0041] As used herein, the term “heterocycle” or “heterocyclic system” means a cyclic compound which consists of carbon atoms and from 1 to 2 heteroatoms independently selected from the group consisting of nitrogen and oxygen atoms. The nitrogen atom may optionally be oxidized. The heterocyclic ring may be attached to its pendant group at any heteroatom or carbon atom which results in a stable structure. The heterocyclic rings described herein may be substituted on carbon or on a nitrogen atom if the resulting compound is stable. If specifically noted, a nitrogen in the heterocycle may optionally be quaternized.
[0042] Examples of heterocycles include, but are not limited to piperidinyl, morpholinyl, or piperazinyl groups.
[0043] As used herein, “pharmaceutically acceptable salts” refer to derivatives of the disclosed compounds wherein the parent compound is modified by making acid or base salts thereof. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. The pharmaceutically acceptable salts include the conventional non-toxic salts or the quaternary ammonium salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, and the like.
[0044] The pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington's Pharmaceutical Sciences, 18th ed., Mack Publishing Company, Easton, Pa., 1990, p. 1445, the disclosure of which is hereby incorporated by reference.
[0045] The compounds of the present invention are useful in the form of the free base or acid or in the form of a pharmaceutically acceptable salt thereof. All forms are within the scope of the invention.
[0046] The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication commensurate with a reasonable risk/benefit ratio.
[0047] The term “pharmaceutically acceptable prodrugs” as used herein means those prodrugs of the compounds useful according to the present invention which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable risk/benefit ratio, and effective for their intended use, as well as zwitterionic forms, where possible, of the compounds of the invention.
[0048] The term “prodrugs”, as the term is used herein, are intended to include any covalently bonded carriers which release an active parent drug of the present invention in vivo when such prodrug is administered to a mammalian subject. Since prodrugs are known to enhance numerous desirable qualities of pharmaceuticals (i.e., solubility, bioavailability, manufacturing, etc.) the compounds of the present invention may be delivered in prodrug form. Thus, the skilled artisan will appreciate that the present mention encompasses prodrugs of the presently claimed compounds, methods of delivering the same, and compositions containing the same. Prodrugs of the present invention are prepared by modifying functional groups present in the compound in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent compound. The transformation in vivo may be, for example, as the result of some metabolic process, such as chemical or enzymatic hydrolysis of a carboxylic, phosphoric or sulphate ester, or reduction or oxidation of a susceptible functionality. Prodrugs include compounds of the present invention wherein a hydroxy, amino, or sulfhydryl group is bonded to any group that, when the prodrug of the present invention is administered to a mammalian subject, it cleaves to form a free hydroxyl, free amino, or free sulfydryl group, respectively. Functional groups which may be rapidly transformed, by metabolic cleavage, in vivo form a class of groups reactive with the carboxyl group of the compounds of this invention. They include, but are not limited to such groups as alkanoyl (such as acetyl, propionyl, butyryl, and the like), unsubstituted and substituted aroyl (such as benzoyl and substituted benzoyl), alkoxycarbonyl (such as ethoxycarbonyl), trialkylsilyl (such as trimethyl- and triethysilyl), monoesters formed with dicarboxylic acids (such as succinyl), and the like. Because of the ease with which the metabolically cleavable groups of the compounds useful according to this invention are cleaved in vivo, the compounds bearing such groups can act as pro-drugs. The compounds bearing the metabolically cleavable groups have the advantage that they may exhibit improved bioavailability as a result of enhanced solubility and/or rate of absorption conferred upon the parent compound by virtue of the presence of the metabolically cleavable group. A thorough discussion of prodrugs is provided in the following: Design of Prodrugs, H. Bundgaard, ed., Elsevier, 1985; Methods in Enzymology, K. Widder et al, Ed., Academic Press, 42, p.309-396, 1985; A Textbook of Drug Design and Development, Krogsgaard-Larsen and H. Bundgaard, ed., Chapter 5; “Design and Applications of Prodrugs” p.113-191, 1991; Advanced Drug Delivery Reviews, H. Bundgard, 8, p.1-38, 1992; Journal of Pharmaceutical Sciences, 77, p. 285, 1988; Chem. Pharm. Bull., N. Nakeya et al, 32, p. 692, 1984; Pro-drugs as Novel Delivery Systems, T. Higuchi and V. Stella, Vol. 14 of the A.C.S. Symposium Series, and Bioreversible Carriers in Drug Design, Edward B. Roche, ed., American Pharmaceutical Association and Pergamon Press, 1987, each of which is herein incorporated by reference in their entirety as though set forth in full.
[0049] The term “treating” refers to: (i) preventing a disease, disorder or condition from occurring in an animal which may be predisposed to the disease, disorder and/or condition but has not yet been diagnosed as having it; (ii) inhibiting the disease, disorder or condition, i.e., arresting its development; and (iii) relieving the disease, disorder or condition, i.e., causing regression of the disease, disorder and/or condition.
Preparation of Compounds of the Invention
[0050] It will be apparent to those skilled in the art that certain compounds of formula (I) can exhibit isomerism, for example geometrical isomerism, e.g., E or Z isomerism, and optical isomerism, e.g., R or S configurations. Geometrical isomers include the cis and trans forms of compounds of the invention having alkenyl moieties. It is well known in the art how to prepare optically active forms, such as by resolution of racemic forms or by synthesis from optically active starting materials. All chiral, diastereomeric, racemic forms and all geometric isomeric forms of a structure are intended, unless the specific stereochemistry or isomer form is specifically indicated.
[0051] Such isomers can be separated from their mixtures, by the application or adaptation of known methods, for example chromatographic techniques and recrystallization techniques, or they are separately prepared from the appropriate isomers of their intermediates, for example by the application or adaptation of methods described herein.
[0052] Where the compound of the present invention is substituted with a basic moiety, acid addition salts are formed and are simply a more convenient form for use; and in practice, use of the salt form inherently amounts to use of the free base form. The acids which can be used to prepare the acid addition salts include preferably those which produce, when combined with the free base, pharmaceutically acceptable salts, that is, salts whose anions are non-toxic to the patient in pharmaceutical doses of the salts, so that the beneficial inhibitory effects on CDK inherent in the free base are not vitiated by side effects ascribable to the anions. Although pharmaceutically acceptable salts of said basic compounds are preferred, all acid addition salts are useful as sources of the free base form even if the particular salt, per se, is desired only as an intermediate product as, for example, when the salt is formed only for purposes of purification, and identification, or when it is used as an intermediate in preparing a pharmaceutically acceptable salt by ion exchange procedures.
[0053] According to a further feature of the invention, acid addition salts of the compounds of this invention are prepared by reaction of the free base with the appropriate acid, by the application or adaptation of known methods. For example, the acid addition salts of the compounds of this invention are prepared either by dissolving the free base in aqueous or aqueous-alcohol solution or other suitable solvents containing the appropriate acid and isolating the salt by evaporating the solution, or by reacting the free base and acid in an organic solvent, in which case the salt separates directly or can be obtained by concentration of the solution.
[0054] The acid addition salts of the compounds of this invention can be regenerated from the salts by the application or adaptation of known methods. For example, parent compounds of the invention can be regenerated from their acid addition salts by treatment with an alkali, e.g. aqueous sodium bicarbonate solution or aqueous ammonia solution.
[0055] Where the compound of the invention is substituted with an acidic moiety, base addition salts may be formed and can be simply a more convenient form for use; and in practice, use of the salt form can inherently amounts to use of the free acid form. The bases which can be used to prepare the base addition salts include those which produce, when combined with the free acid, pharmaceutically acceptable salts, that is, salts whose cations are non-toxic to the animal organism in pharmaceutical doses of the salts, so that the beneficial inhibitory effects on CDK inherent in the free acid are not vitiated by side effects ascribable to the cations. Pharmaceutically acceptable salts, including for example alkali and alkaline earth metal salts, within the scope of the invention are those derived from the following bases: sodium hydride, sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminum hydroxide, lithium hydroxide, magnesium hydroxide, zinc hydroxide, ammonia, ethylenediamine, N-methyl-glucamine, lysine, arginine, ornithine, choline, N,N′-dibenzylethylenediamine, chloroprocaine, diethanolamine, procaine, N-benzylphenethylamine, diethylamine, piperazine, tris(hydroxymethyl)-aminomethane, tetramethylammonium hydroxide, and the like.
[0056] Metal salts of compounds of the present invention may be obtained by contacting a hydride, hydroxide, carbonate or similar reactive compound of the chosen metal in an aqueous or organic solvent with the free acid form of the compound. The aqueous solvent employed may be water or it may be a mixture of water with an organic solvent, preferably an alcohol such as methanol or ethanol, a ketone such as acetone, an aliphatic ether such as tetrahydrofuran, or an ester such as ethyl acetate. Such reactions are normally conducted at ambient temperature but they may, if desired, be conducted with heating.
[0057] Amine salts of compounds of the present invention may be obtained by contacting an amine in an aqueous or organic solvent with the free acid form of the compound. Suitable aqueous solvents include water and mixtures of water with alcohols such as methanol or ethanol, ethers such as tetrahydrofuran, nitrites such as acetonitrile, or ketones such as acetone. Amino acid salts may be similarly prepared.
[0058] The base addition salts of the compounds of this invention can be regenerated from the salts by the application or adaptation of known methods. For example, parent compounds of the invention can be regenerated from their base addition salts by treatment with an acid, e.g. hydrochloric acid.
[0059] Pharmaceutically acceptable salts also include quaternary lower alkyl ammonium salts. The quaternary salts are prepared by the exhaustive alkylation of basic nitrogen atoms in compounds, including nonaromatic and aromatic basic nitrogen atoms, according to the invention, i.e., alkylating the non-bonded pair of electrons of the nitrogen moieties with an alkylating agent such as methylhalide, particularly methyl iodide, or dimethyl sulfate. Quaternarization results in the nitrogen moiety becoming positively charged and having a negative counter ion associated therewith.
[0060] As will be self-evident to those skilled in the art, some of the compounds of this invention do not form stable salts. However, acid addition salts are more likely to be formed by compounds of this invention having a nitrogen-containing heteroaryl group and/or wherein the compounds contain an amino group as a substituent. Preferable acid addition salts of the compounds of the invention are those wherein there is not an acid labile group.
[0061] As well as being useful in themselves as active compounds, salts of compounds of the invention are useful for the purposes of purification of the compounds, for example by exploitation of the solubility differences between the salts and the parent compounds, side products and/or starting materials, by techniques well known to those skilled in the art.
[0062] Compounds according to the invention, for example, starting materials, intermediates or products, are prepared as described herein or by the application or adaptation of known methods, by which is meant methods used heretofore or described in the literature, for example those described by R. C. Larock in Comprehensive Organic Transformations, VCH publishers, 1989.
[0063] In the reactions described hereinafter it may be necessary to protect reactive functional groups, for example hydroxy, amino, imino, thio or carboxy groups, where these are desired in the final product, to avoid their unwanted participation in the reactions. Conventional protecting groups may be used in accordance with standard practice, for examples see T. W. Green and P. G. M. Wuts in “Protective Groups in Organic Chemistry” John Wiley and Sons, 1991; J. F. W. McOmie in “Protective Groups in Organic Chemistry” Plenum Press, 1973.
[0064] The compounds useful according to the invention optionally are supplied as salts. Those salts which are pharmaceutically acceptable are of particular interest since they are useful in administering the foregoing compounds for medical purposes. Salts which are not pharmaceutically acceptable are useful in manufacturing processes, for isolation and purification purposes, and in some instances, for use in separating stereoisomeric forms of the compounds of this invention. The latter is particularly true of amine salts prepared from optically active amines. Where the compound useful according to the invention contains a carboxy group, or a sufficiently acidic bioisostere, base addition salts may be formed and are simply a more convenient form for use; and in practice, use of the salt form inherently amounts to use of the free acid form.
[0065] Also, where the compound useful according to the invention contains a basic group, or a sufficiently basic bioisostere, acid addition salts may be formed and are simply a more convenient form for use; and in practice, use of the salt form inherently amounts to use of the free base form.
[0066] The foregoing compounds useful according to the invention may also be combined with another therapeutic compound to form pharmaceutical compositions (with or without diluent or carrier) which, when administered, provide simultaneous administration of two or more active ingredients resulting in the combination therapy of the invention.
[0067] While it is possible for compounds useful according to the invention to be administered alone it is preferably to present them as pharmaceutical compositions. The pharmaceutical compositions, both for veterinary and for human use, useful according to the present invention comprise at lease one compound of the invention, as above defined, together with one or more acceptable carriers therefor and optionally other therapeutic ingredients. The skilled artisan will appreciate the abundance of publications setting forth the state of the art for pharmaceutical administration.
[0068] Examples of suspending agents include ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth, or mixtures of these substances. Prevention of the action of microorganisms can be ensured by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, and the like. It may also be desirable to include isotonic agents, for example sugars, sodium chloride and the like. Prolonged absorption of the injectable pharmaceutical form can be brought about by the use of agents delaying absorption, for example, aluminum monosterate and gelatin. Examples of suitable carriers, diluents, solvents or vehicles include water, ethanol, polyols, suitable mixtures thereof, vegetable oils (such as olive oil) and injectable organic esters such as ethyl oleate. Examples of excipients include lactose, milk sugar, sodium citrate, calcium carbonate, dicalcium phosphate phosphate. Examples of disintegrating agents include starch, alginic acids and certain complex silicates. Examples of lubricants include magnesium stearate, sodium lauryl sulphate, talc, as well as high molecular weight polyethylene glycols.
[0069] In certain preferred embodiments, active ingredients necessary in combination therapy may be combined in a single pharmaceutical composition for simultaneous administration.
[0070] The choice of vehicle and the content of active substance in the vehicle are generally determined in accordance with the solubility and chemical properties of the active compound, the particular mode of administration and the provisions to be observed in pharmaceutical practice. For example, excipients such as lactose, sodium citrate, calcium carbonate, dicalcium phosphate and disintegrating agents such as starch, alginic acids and certain complex silicates combined with lubricants such as magnesium stearate, sodium lauryl sulphate and talc may be used for preparing tablets. To prepare a capsule, it is advantageous to use lactose and high molecular weight polyethylene glycols. When aqueous suspensions are used they can contain emulsifying agents or agents which facilitate suspension. Diluents such as sucrose, ethanol, polyethylene glycol, propylene glycol, glycerol and chloroform or mixtures thereof may also be used.
[0071] The oily phase of the emulsions of this invention may be constituted from known ingredients in a known manner. While the oily phase may comprise merely an emulsifier (otherwise known as an emulgent), it desirably comprises a mixture of at least one emulsifier with a fat or an oil or with both a fat and an oil. Preferably, a hydrophilic emulsifier is included together with a lipophilic emulsifier which acts as a stabilizer. It is also preferred to include both an oil and a fat. Together, the emulsifier(s) with or without stabilizer(s) make up the emulsifying wax, and the way together with the oil and fat make up the emulsifying ointment base which forms the oily dispersed phase of a cream formulation. Emulgents and emulsion stabilizers suitable for use in the formulation of the present invention include Tween® 60, Span® 80, cetostearyl alcohol, benzyl alcohol, myristyl alcohol, glyceryl mono-stearate and sodium lauryl sulfate.
[0072] If desired, the aqueous phase of the cream base may include, for example, a least 30% w/w of a polyhydric alcohol, i.e. an alcohol having two or more hydroxyl groups such as propylene glycol, butane 1,3-diol, mannitol, sorbitol, glycerol and polyethylene glycol (including PEG 400) and mixtures thereof. The topical formulations may desirably include a compound which enhances absorption or penetration of the active ingredient through the skin or other affected areas. Examples of such dermal penetration enhancers include dimethyl sulphoxide and related analogues.
[0073] The choice of suitable oils or fats for the formulation is based on achieving the desired cosmetic properties. Thus the cream should preferably be a non-greasy, non-staining and washable product with suitable consistency to avoid leakage from tubes or other containers. Straight or branched chain, mono- or dibasic alkyl esters such as di-isopropyl myristate, decyl oleate, isopropyl palmitate, butyl stearate, 2-ethylhexyl palmitate or a blend of branched chain esters known as Crodamol CAP may be used, the last three being preferred esters. These may be used alone or in combination depending on the properties required. Alternatively, high melting point lipids such as white soft paraffin and/or liquid paraffin or other mineral oils can be used. Solid compositions may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols, and the like.
[0074] The pharmaceutical compositions can be administered in a suitable formulation to humans and animals by topical or systemic administration, including oral, inhalational, rectal, nasal, buccal, sublingual, vaginal, parenteral (including subcutaneous, intramuscular, intravenous, intradermal, intrathecal and epidural), intracisternal and intraperitoneal. It will be appreciated that the preferred route may vary with for example the condition of the recipient.
[0075] The formulations can be prepared in unit dosage form by any of the methods well known in the art of pharmacy. Such methods include the step of bringing into association the active ingredient with the carrier which constitutes one or more accessory ingredients. In general the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both, and then, if necessary, shaping the product.
[0076] A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tables may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, preservative, surface active or dispersing agent. Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered compounds moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active ingredient therein.
[0077] Solid compositions for rectal administration include suppositories formulated in accordance with known methods and containing at least one compound of the invention.
[0078] If desired, and for more effective distribution, the compounds can be microencapsulated in, or attached to, a slow release or targeted delivery systems such as a biocompatible, biodegradable polymer matrices (e.g. poly(d,l-lactide co-glycolide)), liposomes, and microspheres and subcutaneously or intramuscularly injected by a technique called subcutaneous or intramuscular depot to provide continuous slow release of the compound(s) for a period of 2 weeks or longer. The compounds may be sterilized, for example, by filtration through a bacteria retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved in sterile water, or some other sterile injectable medium immediately before use.
[0079] Actual dosage levels of active ingredient in the compositions of the invention may be varied so as to obtain an amount of active ingredient that is effective to obtain a desired therapeutic response for a particular composition and method of administration. The selected dosage level therefore depends upon the desired therapeutic effect, on the route of administration, on the desired duration of treatment and other factors.
[0080] Total daily dose of the compounds useful according to this invention administered to a host in single or divided doses may be in amounts, for example, of from about 0.0001 to about 100 mg/kg body weight daily and preferably 0.01 to 10 mg/kg/day. Dosage unit compositions may contain such amounts of such submultiples thereof as may be used to make up the daily dose. It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the patient's body weight, general health, sex, diet, time and route of administration, rates of absorption and excretion, combination with other drugs and the severity of the particular disease being treated.
[0081] The amount of each component administered is determined by the attending clinicians taking into consideration the etiology and severity of the disease, the patient's condition and age, the potency of each component and other factors.
[0082] The formulations may be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials with elastomeric stoppers, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.
[0083] Administration of a compound of the present invention in combination with additional therapeutic agents, may afford an efficacy advantage over the compounds and agents alone, and may do so while permitting the use of lower doses of each. A lower dosage minimizes the potential of side effects, thereby providing an increased margin of safety. The combination of a compound of the present invention with such additional therapeutic agents is preferably a synergistic combination. Synergy, as described for example by Chou and Talalay, Adv. Enzyme Regul. 22:27-55 (1984), occurs when the therapeutic effect of the compound and agent when administered in combination is greater than the additive effect of either the compound or agent when administered alone. In general, a synergistic effect is most clearly demonstrated at levels that are (therapeutically) sub-optimal for either the compound of the present invention or a known anti-proliferative agent alone, but which are highly efficacious in combination. Synergy can be in terms of improved inhibitory response without substantial increases in toxicity over individual treatments alone, or some other beneficial effect of the combination compared with the individual components.
[0084] Procedures for evaluating the biological activity of compounds or compositions according to the invention are carried out as described herein or by the application or adaptation of known procedures, by which is meant procedures used heretofore or as described in the literature. The compounds of the present invention, their methods or preparation and their biological activity will appear more clearly from the examination of the following examples which are presented as an illustration only and are not to be considered as limiting the invention in its scope. The following examples are but preferred methods of synthesizing the compounds of the invention, which may be prepared according to any method known to the organic chemist of ordinary skill. Other features of the invention will become apparent during the following descriptions of exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof. Each of the cited references are hereby incorporated herein by reference in their entirity as though set forth in full.
EXAMPLES
[0085] The following abbreviations are used throughout the following Examples: “°C” for degrees Celsius, “CIMS” for chemical ionization mass spectroscopy, “eq” for equivalent or equivalents, “g” for gram or grams, “h” for hour or hours, “mg” for milligram or milligrams, “mL” for milliliter or milliliters, “mmol” for millimolar, “M” for molar, “min” for minute or minutes, “p-TsOH” for para-toluenesulphonic acid, “DMF” for dimethylformamide, and “TFA” for trifluoroacetic acid.
Example 1
Preparation of Intermediate 1
[0086] The preparation of intermediate 1, (N-[2-(4-Methoxy-benzoyl)-1,3-dioxo-indan-4-yl]-acetamide) is described in Nugiel, D. A.; Etzkorn, A. M.; Vidwans, A.; Benfield, P. A.; Boisclair, M.; Burton, C. R.; Cox, S.; Czerniak, P. M.; Doleniak, D.; Seitz, S. P. J. Med. Chem. 2001, 44, 1334-1336 which is herein incorporated by reference in it's entirety as though set forth in full.
Example 2
Preparation of Intermediate 2
[0087] Synthesis of 4-Amino-2-(4-methoxy-benzoyl)-indan-1,3-dione: The compound prepared in example 1 (2.0 g, 5.93 mmol) is dissolved in 20% HCl in methanol (50 mL). This solution is stirred at reflux for a period of 3 h. It is then allowed to cool to room temperature and stirred overnight. The product is filtered off, washed with ethanol (20 mL) and air dried to give the product as a yellow solid (1.5 g, 85.7%). mp 268-269° C.; 1 H NMR (DMSOd 6 ) δ 8.17 (d, J=8.8 Hz, 2H), 7.49 (t, 1H), 7.12 (d, J=8.7 Hz, 2H), 6.98 (m, 2H), 3.88 (s, 1H).
Example 3
Preparation of Intermediate 3
[0088] Synthesis of [2-(4-Methoxybenzoyl)-1,3-dioxo-indan-4-yl]-carbamic acid phenyl ester: The product prepared in Example 2 (1.5 g, 5.08 mmol) is dissolved in acetone (40 mL) and treated with sodium carbonate (1.26 g, 15.24 mmol) and phenyl chloroformate (1.19 g, 7.62 mmol). The suspension is stirred at 50° C. for 3 h. The reaction mixture is diluted with water (120 mL), and extracted with ethyl acetate (2×100 mL). The organic layer is separated, washed with brine (50 mL), dried (Na 2 SO 4 ) and the solvent removed at reduced pressure to give a gummy orange residue. Cold ethyl ether (100 mL) is added to this residue to give a precipitate. The precipitate is collected and washed with ethyl ether (2×10 mL) to give desired product as a yellow solid (1.65 g. 78%). mp 256-258° C.; 1 HNMR (DMSOd 6 ) δ 10.83 (s, 1H), 8.08 (d, J=8.0 Hz, 1H), 7.57 (d, J=2.9 Hz, 2H), 7.54 (m, 3H), 7.28 (m, 3H), 7.09 (t, 1H), 6.89 (d, J=10.8 Hz, 2H), 3.81 (s, 3H)
Example 4
Preparation of 1-[3-(4-methoxy-phenyl)-4-oxo-2,4-dihydro-indeno[1,2-c]pyrazol-5-yl]-3-morpholin-4-yl-urea
[0089] [0089]
[0090] The product prepared in Example 3 (0.03 g, 0.072 mmol) in anhydrous DMSO (2 mL) is treated with 4-aminomorpholine (0.0084 g, 0.082 mmol) and 4-dimethylaminopyridine (0.005 g, 0.04 mmol) and heated to 80° C. for 3 h. The solvent is removed under reduced pressure and the residue triturated with ethanol to give a dark solid. The solid is collected and washed with ethanol (5 mL) to give a tricarbonyl urea (0.03 g, 100%). The tricarbonyl urea intermediate (0.03 g, 0.078 mmol) is treated with hydrazine hydrate (0.1 mL, 3.21 mmol) and p-toluenesulfonic acid monohydrate (0.01 g, 0.05 mmol) in refluxing ethanol (4 mL) for a period of 3 h. The reaction mixture is cooled to room temperature, the solid collected, washed with cold ethanol (2×2 mL), and air dried to give the product as a yellowish solid (0.012 g, 41.3%). mp 290-291° C.; 1 H NMR (DMSO-d 6 ) δ 8.27 (d, J=6.8 Hz, 2H), 8.16 (d, J=8.8 Hz, 2H), 7.42 (m, 1H), 7.12 (m, 3H), 3.81 (s, 3H), 2.90 (s, 4H), 2.70 (s, 4H), HRMS calcd. for C 22 H 22 N 5 O 4 (M+H + ) 420.1672; found 420.1688;
Example 5
Preparation of [3-(4-methoxy-phenyl)-4-oxo-2,4-dihydro-indeno[1,2-c]pyrazol-5-yl]-urea
[0091] [0091]
[0092] The product prepared in Example 3 (0.03 g, 0.072 mmol) in anhydrous DMSO (2 mL) is treated with excess ammonium hydroxide solution and 4-dimethylaminopyridine (0.005 g, 0.04 mmol) and is heated to 80° C. for 3 h. The solvent is removed under reduced pressure and the residue triturated with ethanol to give a dark solid. The solid is collected and washed with ethanol (5 mL) to give urea (0.03 g, 100%). The tricarbonyl urea intermediate (0.03 g, 0.078 mmol) is treated with hydrazine hydrate (0.1 mL, 3.21 mmol) and p-toluenesulfonic acid monohydrate (0.01 g, 0.05 mmol) in refluxing ethanol (4 mL) for a period of 3 h. The reaction mixture is cooled to room temperature, the solid collected, washed with cold ethanol (2×2 mL), and air dried to give the product as a yellowish solid (0.018 g, 62.4%). mp 267-269° C.; 1 H NMR (DMSO-d 6 ) δ 9.35 (s, 1H), 8.22 (m, 3H), 7.38 (m, 1H), 7.10 (d, J=8.8 Hz, 2H), 7.02 (d, J=0.7 Hz, 1H), 3.81 (s, 3H); HRMS calcd. for C 18 H 15 N 4 O 3 (M+H + ) 335.1144; found 335.1162;
Example 6
Preparation of 1-(2-amino-cyclohexyl)-3-[3-(4-methoxy-phenyl)-4-oxo-2,4-dihydro-indeno[1,2-c]pyrazol-5-yl]-urea
[0093] [0093]
[0094] The product prepared in Example 3 (0.03 g, 0.072 mmol) in anhydrous DMSO (2 mL) is treated with 1,2-diaminocyclohexane (0.01 g, 0.082 mmol) and 4-dimethylaminopyridine (0.005 g, 0.04 mmol) and heated to 80° C. for 3 h. The solvent is removed under reduced pressure and the residue triturated with ethanol to give a dark solid. The solid is collected and washed with ethanol (5 mL) to give a tricarbonyl urea (0.03 g, 100%). The tricarbonyl urea intermediate (0.03 g, 0.078 mmol) is treated with hydrazine hydrate (0.1 mL, 3.21 mmol) and p-toluenesulfonic acid monohydrate (0.01 g, 0.05 mmol) in refluxing ethanol (4 mL) for a period of 3 h. The reaction mixture is cooled to room temperature, the solid collected, washed with cold ethanol (2×2 mL), and air dried to give the product as a yellowish solid (0.01 g, 30.6%). 1 HNMR (DMSO-d 6 ) δ 9.56 (s, 1H), 8.27 (d, 1H), 8.19 (d, 2H), 7.41 (t, 1H), 7.10 (m, 3H), 4.10 (s, 1H), 3.81 (s, 3H), 3.23 (s, 1H), 1.63 (m, 5H), 1.40 (m, 3H).
Example 7
Preparation of 5-Amino-3-(4-methoxyphenyl)-2-phenyl-2H-indeno-[1,2-c]pyrazol-4-one:
[0095] [0095]
[0096] A suspension of N-[3-(4-Methoxy-phenyl)-4-oxo-2,4-dihydro-indeno[1,2-c]pyrazol-5-yl]-acetamide (as produced according to Nugiel, D. A.; Etzkorn, A. M.; Vidwans, A.; Benfield, P. A.; Boisclair, M.; Burton, C. R.; Cox, S.; Czerniak, P. M.; Doleniak, D.; Seitz, S. P. J. Med. Chem. 2001, 44, 1334-1336) (1.0 g, 3.0 mmol) in MeOH (10 mL) was treated with concentrated HCl (1 mL) and heated to reflux. After stirring the mixture for 2 h the reaction was cooled and the product was collected by filtration and obtained as a greenish solid (0.7 g, 81%). mp 273° C.; NMR (DMSO-d) δ 13.6 (bs, 1H), 8.3 (d, J=8.4 Hz, 1H), 8.1 (d, J=8.8 Hz, 2H), 7.5 (t, J=7.7 Hz 1H), 7.2 (d, J=7.0 Hz, 1H), 7.1 (d, J=8.8 Hz, 2H), 3.8 (s, 3H); HRMS m/e calc'd for C 17 H 14 N 3 O 2 (M+H): 292.1086, found: 292.1080.
Example 8
Preparation of 2-Chloro-N-[3-(4-methoxyphenyl)-4-oxo-2,4-dihydro-indeno[1,2-c]pyrazol-5-yl]-acetamide:
[0097] [0097]
[0098] A suspension of the product prepared in Example 7 (0.2 g, 0.7 mmol) in dioxane (10 mL) was treated with aqueous' saturated NaHCO 3 (3 mL) and chloroacetyl chloride (3 mL, 0.21 mmol). The reaction was heated to 50° C. and stirred for 2 h. The reaction is then cooled, poured into water (20 mL), extracted with EtOAc (100 mL), the organic layer separated, dried (MgSO 4 ) and the solvent removed at reduced pressure. The residue is recrystallized from EtOH to give the product as a yellow solid (0.09 g, 35%). mp>300° C.; NMR (DMSO-d 6 ) δ 13.6 (bs, 1H), 11.3 (s, 1H), 8.3 (d, J=8.4 Hz, 1H), 8.1 (d, J=8.8 Hz, 2H), 7.5 (t, J=7.7 Hz 1H), 7.2 (d, J=7.0 Hz, 1H), 7.1 (d, J=8.8 Hz, 2H), 4.5 (s, 2H), 3.8 (s, 3H); HRMS m/e calc'd for C 19 H 15 N 3 O 3 Cl (M+H): 368.0802, found: 368.0818.
Example 9
Preparation of 2-(4-aminomethyl-piperidin-1-yl)-N-[3-(4-methoxy-phenyl)-4-oxo-2,4-dihydro-indeno[1,2-c]pyrazol-5-yl]-acetamide
[0099] [0099]
[0100] A suspension of product prepared according to Example 8 (0.015 g, 0.04 mmol) in EtOH (1 mL) is treated with 4-aminomethylpiperdine (0.75 mL), placed in a sealed tube and heated to 80° C. for 3 h. The reaction is cooled and the solvent removed at reduced pressure. The residue is recrystallized from EtOH to give the product as a yellow solid (0.009 g, 62%).mp>300° C.; NMR (DMSO-d 6 ) δ 13.6 (bs, 1H), 11.3 (s, 1H), 8.35 (d, J=8.4 Hz, 1H), 8.1 (d, J=8.8 Hz, 2H), 7.5 (t, J=7.7 Hz 1H), 7.2 (d, J=7.0 Hz, 1H), 7.1 (d, J=8.8 Hz, 2H), 3.8 (s, 3H), 3.2 (bs, 2H), 2.9(bs, 2H), 2.5 (d, J=8.0 Hz, 2H), 2.2 (t, J=8.0 Hz, 2H), 1.6 (m, 5H); HRMS m/e calc'd for C 25 H 28 N 5 O 3 (M+H): 446.2192, found: 446.2169; Anal. (C 25 H 27 N 5 O 3 ) C, H, N.
Example 10
Preparation of 2-(4-Methoxybenzoyl)-3-methoxycarbonylamino-indan-1,3-dione:
[0101] [0101]
[0102] A solution of 3-methoxycarbonylamino-phthalic acid dimethyl ester (1 g, 4.8 mmol) and 4-methoxyacetophenone (0.72 g, 4.8 mmol) in dry DMF (3 mL) was heated to 90° C. Sodium hydride (0.21 g, 60% suspension in oil, 5.2 mmol) is added in one portion and the exothermic reaction turns deep red. After 20 min, the reaction is cooled to room temperature, diluted with water (25 mL) extracted with EtOAc (10 mL) and the aqueous phase separated. The aqueous phase is acidified to pH 2 with 2N HCl and the crude product collected. Recrystallization with ethanol gives the desired product as a yellow solid (0.4 g, 30%). ESIMS 352 (M−H, 100%).
Example 11
Preparation of 3-(4-Methoxyphenyl)-5-methoxycarbonylamino-2H-indeno-[1,2-c]pyrazol-4-one:
[0103] [0103]
[0104] A solution of 2-(4-methoxybenzoyl)-3-methoxycarbonylamino-indan-1,3-dione (0.2 g, 0.6 mmol) in EtOH (5 mL) is treated with hydrazine hydrate (0.1 mL, 1.8 mmol) and p-TsOH (3 mg). The reaction is heated to reflux and stirred for 2 h. The reaction is cooled to room temperature and the product crystallized from the reaction mixture. The product is collected by filtration as a yellow solid (0.1 g, 50%). mp>300° C.; HRMS m/e calc'd for C 19 H 16 N 3 O 4 (M+H): 350.1141, found: 350.1168.
Utility
[0105] Inhibition of Kinase/Cyclin Complex Enzymatic Activity
[0106] Several of the compounds disclosed in this invention were assayed for their inhibitory activity against cdk4/D1 and cdk2/E kinase complexes. The in vitro assays employ cell lysates from insect cells expressing either of the kinases and subsequently their corresponding regulatory units. The cdk2/cyclin E is purified from insect cells expressing His-tagged cdk2 and cyclin E. The cdk/cyclin lysate is combined in a microtitre-type plate along with a kinase compatible buffer, 32 P-labeled ATP at a concentration of 50 mM, a GST-Rb fusion protein and the test compound at varying concentrations. The kinase reaction is allowed to proceeded with the radiolabled ATP, then effectively stopped by the addition of a large excess of EDTA and unlabeled ATP. The GST-Rb labeled protein is sequestered on a GSH-Sepharose bead suspension, washed, resuspended in scintillant, and the 32 p activity detected in a scintillation counter. The compound concentration which inhibits 50% of the kinase activity was calculated for each compound. A compound was considered active if its IC 50 was found to be less than 1 μM.
Inhibition of HCT 116 Cancer Cell Proliferation
[0107] To test the cellular activity of several compounds disclosed in this invention, we examined the effect of these compounds on cultured HCT116 cells and determined their effect on cell-cycle progression by the calorimetric cytotoxcity test using sulforhodamine B (Skehan et al. J. Natl. Cancer Inst. 82:1107-12, 1990). Briefly, HCT116 cells are cultured in the presence of test compounds at increasing concentrations. At selected time points, groups of cells are fixed with trichloroacetic acid and stained with sulforhodamine B (SRB). Unbound dye was removed by washing and protein-bound dye was extracted for determination of optical density. A compound was considered active if its IC 50 was found to be less than 10 μM.
[0108] All patents, patent applications and other publications are herein incorporated by reference in their entirity as though set forth in full.
[0109] The scope of the following claims is intended to encompass all obvious changes in the details, materials and synthesis that will occur to one of ordinary skill in the art.
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The present invention relates to the synthesis of a new class of 5-substituted-3-(4-OR 1 -phenyl)-2H-indeno[1,2-c]pyrazol-4-ones of formula (I):
that are potent inhibitors of the class of enzymes known as cyclin dependent kinases, which relate to the catalytic subunits cdk1-7 and their regulatory subunits know as cyclins A-G.
This invention also provides a novel method of treating cancer or other proliferative diseases by administering a therapeutically effective amount of one of these compounds or a pharmaceutically acceptable salt form thereof. Alternatively, one can treat cancer or other proliferative diseases by administering a therapeutically effective combination of one of the compounds of the present invention and one or more other known anti-cancer or anti-proliferative agents.
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This application claims priority to and is a continuation of pending U.S. patent application entitled, An Apparatus and Method for Producing Microcomponents and Use Of, filed Dec. 8, 2008, having a Ser. No. 12/330,028, the disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for producing microcomponents with component structures which are generated in a process chamber on a substrate according to the LIGA method. The invention further relates to a method for producing microcomponents with component structures in which the microcomponents are generated in provided substrates and thereafter are relieved from the enclosing material sections, such that the material sections can be etched away (stripped). The invention further relates to the use of such an apparatus and method for stripping or removing the material sections enclosing the microcomponents.
Apparatuses and methods of this kind with which microcomponents are produced for the clock industry are well known from the state of the art. Methods are frequently used here which are based on a combination of lithography and electroplating. These methods are generally well known as LIGA methods. In such a “LIGA” method, a photoresist can be applied at first to a substrate such as a wafer or the like. A negative resist with the designation SU-8 can be used as a photoresist.
The substrate can concern a silicon wafer for example which comprises a thin gold layer on its surface on which microcomponents can grow especially well. The photoresist is applied to this silicon wafer. It especially covers the gold layer and can be exposed there selectively by means of a suitable exposure system and a mask. The unexposed places of the photoresist layer are removed in a subsequent development step.
In a subsequent electroplating process, a metal such as nickel or gold can be allowed to grow on the thus prepared substrate surface, with the respective metal beginning to grow on the places stripped of the photoresist layer. Depending on the intended application, growth can be stopped when the grown metal structure grows slightly beyond the photoresist layer.
Photoresist SU-8 comes with the disadvantage that the removal of the cross-linked SU-8 structures between metal structures deposited by electroplating is currently very complex. SU-8 is based on epoxy resin which in the cross-linked state is very stable against organic and inorganic etchants. Photoresist is removed by means of currently known etchants either very slowly or in such a way that the metallic microcomponents are also attacked and thus become useless.
Mechanical removal of the photoresist from the microcomponent is not only laborious and cost-intensive, but also causes a high rejection rate due to the extremely small dimensions of the microcomponents. Some complex structural shapes cannot even be produced at all under these conditions.
Conventional plasma methods progress on the one hand very slowly and on the other hand the metal is attacked by ions and electrons. The etching process needs to be interrupted frequently because the substrates otherwise will become too hot.
In previous methods, the end of the stripping process, i.e. the removal of the photoresist, is determined on the basis of integral temperature measurement by means of emission spectroscopy, which entails very high costs. When photoresist is removed in an etching chamber in batch operations from several microcomponents on the respective substrates, it was only possible to date to recognize the start of the etching process by means of a rise in the integral process temperature and the global end of the etching process by means of the drop in the integral process temperature. It was not possible to individually monitor the individual substrates which may have differently thick layers of photoresist and thus require differently long stripping periods. It was further not possible to recognize in time whether an individual substrate will become too hot due to a bad contact to the substrate holder for example which rests on a work plate and will thus be damaged.
WO 2004/104704 A2 discloses a lithographic method for producing microcomponents. It is tried to form etching chambers in a constructional way, through which removal of SU-8 is facilitated. Several intermediate steps are added as a result of additional bonding layers, support structures, masks and exposure steps, through which construction and production of the microcomponents becomes more laborious.
SUMMARY OF THE INVENTION
From all the aforementioned disadvantages of the state of the art, the invention is based on the object of ensuring that the photoresist is to be stripped as easily, efficiently and reliably as possible, so that rejects are minimized.
The simplicity of production shall be achieved by utilizing and combining already existing techniques and systems with as few as possible, but effective additional steps. Efficiency of production shall be raised by the possibility of simultaneous treatment of several substrates in an etching chamber and by reducing the stripping duration through an increased removal rate of the photoresist. The reliability of the production and thus the reduction in the number of the damaged microcomponents shall be implemented with the help of individual temperature monitoring and lowering the substrate temperature and by avoiding aggressive etchants.
The object of the invention is achieved in respect of its method in such a way that the photoresist is stripped with the help of a cooled remote plasma source by chemical etching due to the increased density of the radicals, with the temperature of the microcomponents being monitored individually and the progression of the temperature being subjected to the recognition of an end point.
The use of a remote plasma source for stripping photoresist offers the advantage that no ions or electrons will reach the substrate and place a thermal load on the same. The radicals strip the photoresist through pure chemical etching. The density of radicals is increased by using a microwave source such as the one from R3T GmbH. A suitable apparatus by means of which the etching process as explained above can be performed especially well is described in the patent specification DE 198 47 848 C1. The apparatus described there comprises a generator for generating electromagnetic waves such as a microwave generator. The electromagnetic waves can be used to form excited and/or ionized particles in a plasma zone. At least the excited particles are conveyed by means of a suitable feed line to the etching chamber in order to trigger there the desired etching process on the surfaces of the substrates. Since the plasma chamber of the source is cooled with a coolant such as water, a cooled beam of radical particles of high radical density is introduced for stripping into the etching chamber, through which a high removal rate is achieved which rises with the density of the radicals on the one hand, and the thermal loading of the substrates, apart from the unavoidable reaction heat, is minimized on the other hand.
For an especially advantageous embodiment of the invention, thermal sensors are distributed over the entire work area for individually checking the local substrate temperatures. They are held in a resilient manner in the work plate, so that a mechanical and thus thermal contact is ensured with the bottom side of a substrate holder on which the substrate is located. It is understood that the substrate can also be placed directly on the work plate, and in this case the thermal sensors would have direct contact with the bottom side of the substrate. It has been seen that as a result of the temperature data measured in real time, especially on each of the substrates, it is possible to draw precise conclusions on the progress of the etching process, advantageously on each of the substrates.
The term “substrate” describes any structure which can be used as a carrier on which the microstructures can grow. Widely used as silicon wafers which can be provided with a thin gold layer, with said gold layer being used as a starting layer from which the microstructures will grow. In the present connection, the term wafer shall generally be used synonymously for the term “substrate”.
“Substrate holders” shall mean such structures which can produce contact between the substrates and the work plate. A substrate is applied to their upper side by means of a contact means and the work plate is located on its bottom side. It is ensured that heat from the substrates which become hot as a result of reaction heat is forwarded via the contact means to the substrate holder and from there to the work plate. Furthermore, a substrate holder is used for horizontally planar positioning of a substrate in an etching chamber.
Any devices are suitable as a “work plate” on which the provided substrates can be arranged either with or with a substrate holder within the etching chamber. Ideally, a cooling medium flows through the work plate in order to thus enable the removal of the process heat from the etching chamber.
The term “etching chamber” describes any device in which the production of microstructures can be made. In such a chamber, a photoresist layer can be removed from a substrate surface and/or a microstructure surface for example.
The term “contact means” describes any means which is suitable of improving the contact between the provided substrates and the substrate holders, so that temperature differences between the provided substrates and the work plate can be compensated in a better way than without such contact means. It is understood that such contact means can be realized in many ways as long as an especially intimate contact is produced between the substrate and the substrate holder.
In accordance with the invention, these contact means provide a substantially better contact between the provided substrates and the substrate holders, so that critical thermal energy present in the substrates and/or the microstructures can be dissipated in a substantially better way into the work plate, thus considerably reducing a thermal loading of the substrates, and the microstructures in particular, in an advantageous manner. The likelihood is reduced or ideally excluded that the microstructures to be produced are damaged or even rendered useless as a result of critical temperature conditions.
When the contact means comprise wax, it is possible to produce a very intensive contact between the provided substrates and substrate holders by means of the wax in an especially simple constructional way. Moreover, the wax can be removed easily from the substrates or the microstructures that have grown thereon when an etching process has been completed for example and the microstructures are to be relieved of further impurities.
Wax as a contact means allows compensating in a very effective way for very small uneven portions on the bottom side of the substrate and/or the upper side of the substrate holder caused by possible production faults or undesirable particles, so that the substrate is aligned in an horizontally planar way and is thus provided with optimal contact to the substrate holder and thus to the work plate, thus producing a favorable thermal contact for heat dissipation.
It is further especially advantageous to use the individually transmitted temperature curves as evaluation criteria for individual recognition of the end points. The transmitted temperatures rise at the beginning of the stripping process from a starting temperature such as the temperature of the work plate to the respective temperature maximum as a result of reaction heat and remain stable as long as the reaction progresses. With the end of the stripping process, the temperatures start to decrease rapidly. The start, middle, end or other suitable places of the decreasing flank of the individual temperature curve is recognized as the individual end point of the stripping process.
Ideally, a monitoring device which can be a computer or the like for example and displays and monitors the temperatures individually sent by the thermal sensors signalizes the end of the stripping process either acoustically and/or visually, so that the operator optionally removes the finished stripped microcomponent from the etching chamber or waits until further microcomponents have been completely stripped.
It would also be possible to arrange the monitoring device in such a way that the stripping process is controlled automatically.
The object of the invention is achieved by means of the apparatus in such a way that a microwave source is arranged outside of the etching chamber to increase the density of the radicals.
The arrangement of a plasma chamber outside of the etching chamber is further advantageous. Ideally, said plasma chamber is cooled with a cooling medium. Water or other agents are considered as cooling medium for example which are able to dissipate heat from the plasma chamber.
A remote plasma method can preferably be used in this connection in which the plasma is generated advantageously outside of an etching chamber and ideally no ions and/or electrons reach a substrate within the etching chamber. The substrate is advantageously not additionally thermally loaded by these ions or electrons. In particular, an already cooled radical particle beam with a density of radicals can be provided favorably especially with the apparatus as described above from the patent specification DE 198 47 848 C1.
The arrangement of the spring-supported thermal sensors in the work place beneath the substrate positions is especially advantageous. The thermal sensors have contact with the bottom side of the substrate holder or with the bottom side of the substrate when no substrate holders are used. Ideally, a spring-supported thermal sensor is associated with each employed substrate or substrate holder. Individual temperature measurement and monitoring of each substrate in real time are thus ensured.
Ideally, a monitoring device will be used which will individually display the temperatures in real time determined by the thermal sensors and will monitor them by means of suitable criteria. The monitoring comprises the determination of the end points and signaling the termination of the stripping processes. It shall further be monitored whether a stripping process will run according to a predetermined scheme. If malfunctions occur such as the overheating of a substrate, the monitoring device will signalize this malfunction and will initiate suitable measures so that the substrate will not be damaged.
The arrangement of a monitoring device at a location which need not necessarily be close to the plasma chamber is further advantageous. The operator can conveniently observe the stripping process in real time from his/her office. When a completed stripping process is signalized via the monitoring device, the operator can decide whether or not this completed microcomponent is removed from the etching chamber.
As a result of the advantages explained above, the application of the described apparatus and method is well-suited for stripping photoresist for microcomponents with component structures.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained below in closer detail by reference to an embodiment shown in the drawings, which show schematically:
FIG. 1 shows a sectional enlarged view of a microcomponent on a substrate produced according to the LIGA method;
FIG. 2 shows a sectional view of an apparatus for producing microcomponents;
FIG. 3 shows a detailed view of the work plate of FIG. 2 , and
FIG. 4 shows an exemplary visualization of three temperature curves of three substrates.
DETAILED DESCRIPTION
FIG. 1 shows a microcomponent on a substrate 14 produced according to the LIGA method. Photoresist 1 encloses the metal 2 which was electroplated to a gold layer 3 which is used as a starter layer.
The apparatus 10 for producing microstructures (not shown here) as shown in FIG. 2 comprises an etching chamber 12 in which a thermostatic work plate 13 is arranged.
A microwave source 18 is arranged outside of the etching chamber 12 . Furthermore, a water-cooled plasma chamber 11 is shown which is also located outside of the etching chamber 12 . The microwave source 18 can be used to produce cooled remote plasma 19 in the water-cooled plasma chamber 11 . A detailed description of how the present remote plasma process works in detail shall be omitted in this case because the remote plasma process concerns a well-known method. A respectively suitable apparatus and respectively suitable methods are also described in detail in the initially mentioned patent specification DE 198 47 848 C1.
In the present case, the generated remote plasma 19 is advantageously already cooled by means of the water-cooled plasma chamber 11 , so that in this way an advantageous reduction in temperature can already be realized concerning the etching process yet to be explained.
The present remote plasma method can be controlled by means of the apparatus 10 shown here in such a way that a cooled radical particle beam 20 will reach the etching chamber 12 with an especially high density of radicals.
As is also mainly shown in the illustration according to FIG. 3 , substrates 14 are arranged on a thermostatic work plate 13 . In the sectional views of this specific embodiment, two substrates 14 are placed by means of two substrate holders 15 on the work plate 13 . Reaction heat which is produced during an etching process for example in which areas of material (not shown here) such as the photoresist layer SU-8 are etched away from the substrates 14 can be dissipated away from the substrates 14 in an especially advantageous manner. This dissipation of the reaction heat is achieved especially well when the two substrate holders 15 are made of thermally well-conducting material. To ensure that the heat transmission can be achieved over the full surface area from the illustrated substrates 14 to the substrate holders 15 , a contact means 16 (see FIG. 3 in particular) is each arranged between the substrates 14 and the respective substrate holders 15 . These layers of contact means are also used for horizontally planar positioning of the substrates 14 on the substrate holders 15 in the etching chamber 12 . The contact means 16 in this embodiment is made of wax.
The wax layers are used to position the substrates 14 in a fixed but detachable way and individually above the respective substrate holders 15 . Both the wax layers as well as the substrate holders 15 especially represent means within the terms of the invention for placing in a planar way the provided substrates 14 on the thermostatic work plate 13 .
The wax layers ensure very advantageously that the already mentioned reaction heat is dissipated from the substrates 14 and thus also from the microstructures (not shown here explicitly) to be produced, so that especially the microstructures are also thermally loaded in a lesser way, as a result of which the rejection of microstructures can be reduced advantageously.
Moreover, spring-supported thermal sensors 17 are provided in the thermostatic work plate 13 which can be used to detect the current temperatures directly on the substrate holders 15 .
This ensures advantageously to realize a monitoring of the actually existing temperatures directly on the substrate holders 15 and thus also on the substrates 14 and the respective microstructures.
A thermal sensor 17 is preferably associated with each substrate holder 15 and each substrate 14 which is arranged on the work plate 13 . It can thus reliably and permanently be ensured that each of the existing thermal sensors 17 is in operative contact with the associated substrate holder 15 .
When the thermal sensors 17 are held in a resilient or spring-supported manner, as shown in FIG. 3 , it can be ensured especially well that the thermal sensors 17 are always pressed with sufficient force against the substrate holders 15 .
Since there is a direct connection between the temperatures applied to the substrates 14 and the presence of photoresist that still needs to be etched away, it is possible to draw conclusions on the basis of the determined temperature data on how far the etching process has already progressed on one of the substrates 14 , as already described above. In particular, due to a rapidly falling temperature during the etching process it is possible to recognize whether an etching process has already finished on one of the substrates 14 because no reaction heat is then produced on this substrate.
In order to enable a respective evaluation of the temperature data detected by means of the thermal sensors 17 it is advantageous when the present apparatus 10 comprises a suitable monitoring device which offers the possibility for visualizing the detected temperature data by means of display means 24 .
The present example visually shows in the display means 24 a first temperature curve 21 of a substrate 14 , a second temperature curve 22 of another substrate 14 and a third temperature curve 23 of a third substrate (not shown here).
The temperature curves 21 , 22 and 23 show the respective temperatures on the respective substrates 14 over a specific period of time. It is described on the basis of the first temperature curve 21 in which phase the first substrate 14 is located. At the beginning of the etching process, the substrate 14 on which the first spring-supported thermal sensor 17 is arranged has an initial temperature 21 a which is close to the temperature of the thermostatic work plate. With the start of the stripping process, the temperature on the substrate 14 rises to an equilibrium temperature 21 b . The equilibrium temperature will occur when the temperature gradient occurring towards the work plate 13 is dissipating the reaction heat from the substrate 14 . The equilibrium temperature remains virtually constant as long as the stripping process occurs in this substrate 14 . Once the substrate 14 has been stripped of photoresist, the temperature will start to drop. The start, middle, end or other suitable places of the decreasing flank of the temperature curve can be recognized as the end point of the stripping process 21 c . The possibility for setting an optimal etching duration is given by suitable setting of the end point recognition.
The present apparatus can be used to display different temperatures and different temperature curves 21 , 22 , 23 in connection with each of the substrates 14 , so that an evaluation of the respectively occurring etching process on the respective substrate 14 can be made rapidly and securely. Reasons for the different temperature curves can be differently running reactions on the respective substrate 14 which may indicate differently thick layers of resist.
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An apparatus and the use of such an apparatus and method for producing microcomponents with component structures are presented which are generated in a process chamber on a substrate according to the LIGA method for example and are stripped from the enclosing photoresist with the help of a cooled remote plasma source.
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PRIORITY
This application claims the benefit of priority, pursuant to §35 USC 119(e), to U.S. provisional patent application Ser. No. 60/478,630, filed Jun. 13, 2003 which is incorporated herein by reference.
FIELD OF INVENTION
This invention relates generally to a GUI based computers and more particularly to a method and system for managing cascaded window arrangements in way that continually displays each window in the cascaded set of windows on a desktop display no matter which window is selected as active. The invention provides a set of extensible methods of making disparate applications within a given operating system environment behave in a manner that is consistent with the foregoing.
BACKGROUND OF THE INVENTION
Current Graphical User Interface (“GUI”) based operating systems (“OS”) deploy various methods for allowing users to organize various application windows on their desktops. The current organizational techniques feature a number of basic window arrangements such as tiling, cascading and free form placement both within a single application and across multiple applications. It is desirable for these applications to be running simultaneously within the OS in a manner that allows the user to easily move or switch from one to another. None of these current applications provide a method for cascading a set of windows such that at least a portion of the windows are concurrently visible on the desktop display so as to maintain a continuously viewable organization as different windows in the cascade are activated.
The advantage of a cascaded window set is that all of the windows are viewable on the desktop without taking up a lot of desktop real estate. The disadvantage to prior approaches to cascading is that as soon as any window located behind the top window in a cascade is selected, it obscures the other windows in the cascade. Operating systems allow applications to “hook” into existing applications so that the existing applications can be augmented or controlled. The invention utilizes this technique in a novel and unobvious way to achieve its goal of providing a display that enables a plurality of application vendors to be cascaded so they are visible on the display.
SUMMARY OF THE INVENTION
The present invention provides a method and system of maintaining and controlling the ordering and placement for display of individual GUI windows into groups or “decks” similar to a deck of playing cards on a desktop area of a computer display. The decks comprise collections of cascaded windows. These decks are controlled such that the title bar of all of the windows of the deck are always simultaneously visible to the user no matter which window is selected as the active window. The act of moving the current top window back into a new position in the deck is defined as “shuffling” the windows. Further, the invention provides auto-deck processes that automatically cascade defined applications, such as Internet Explorer windows, into a deck. In addition, the invention features user-definable options as to the order of the shuffle, and includes the ability to drag the active window out of the deck and to drag any window into the deck. Also the invention allows for the automatic resizing of all windows in a deck by just resizing the active window. Further the invention allows for a predetermined grouping of different applications into the same deck.
The invention results in improved PC desktop display real estate usage while at the same time making it easier and quicker for users to access disparate windows displayed on the desktop.
According to one aspect of the present invention, a computer-implemented method is provided for managing a plurality of windows displayed on a computer. The method includes arranging the plurality of windows into a deck; and causing at least a portion of each window within the deck to be displayed regardless of which window in the deck is active.
According to another aspect of the present invention, a computer-readable medium having computer-executable instructions for performing a method for managing a plurality of windows displayed on a computer is provided. The method includes arranging the plurality of windows into a deck; and causing at least a portion of each window within the deck to be displayed regardless of which window in the deck is active.
According to another aspect of the present invention, a data processing system for use on a computer is provided. The system includes cascade logic for arranging a plurality of windows into a deck; and display logic for causing at least a portion of each window within the deck to be displayed regardless of which window in the deck is active.
These and other features, advantages, and objects of the invention will become apparent by reference to the following specification and by reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic pictorial view of an example of the shuffling process of the invention for three GUI windows in a deck.
FIG. 2 is a table showing exemplary application window property data structures indicating one instance per window on the desktop whether decked or not.
FIG. 3 is a table showing exemplary data structures for standard and MDI decks indicating one instance for each active deck on the desktop.
FIG. 4 is a table showing exemplary program specific data structures indicating one for each program specified in the initialization file (INI file).
FIG. 5 is a table of exemplary data structures that describe structures used to identify specific windows on the desktop by a character match in their title bar so that special processing can be applied to that particular window.
FIG. 6 is a table of exemplary data structures for applications that are to be auto-decked.
FIG. 7 is a table of exemplary data structures for each process running on the desktop with a top level window.
FIG. 8 is a table of exemplary data structures for each thread running on the desktop with a top level window.
FIG. 9 is a table showing an exemplary MDI application data structure that holds the window handle of the MDI client window of an MDI application, one per MDI program instance.
FIG. 10 is a table of exemplary data structures describing global user settable parameters of the invention.
FIG. 11 is a table of exemplary data structures for describing the flags used for each client window being controlled by the invention.
FIG. 12 is an exemplary list of windows messages that are managed by the invention. The first column is a reference to each message number that is charted in FIGS. 13–17 . The next column is a reference to the main logic flow chart shown in the figures. The next column indicates the source of the message, and the last column is the message name.
FIGS. 13–17 illustrate the basic flow that takes place for each message listed in FIG. 12 .
FIG. 18 is an exemplary flow chart that details an initialization process of the invention.
FIG. 19 is an exemplary flow chart that details an actual deck shuffling process of the invention.
FIG. 20 is an exemplary flow chart that details how the invention detects windows that are dragged and dropped on the desktop. The figure shows three cases that relate to the invention:
1. Adding a window into another window creating a new deck or to an existing deck. 2. Removing the active window from a deck. 3. Moving the entire deck to a new location.
FIG. 21 is an exemplary flow chart that describes the process that takes place in the invention whenever a new window is detected on the desktop.
FIG. 22 is an exemplary flow chart that describes a sub-process that takes place in the invention that handles the logic to add a new window into a deck.
FIG. 23 is an exemplary flow chart describing logic used by the invention whenever a window in a deck is resized.
FIG. 24 is an exemplary flow chart describing logic for integrating new applications into a processing framework of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The present invention will now be described in detail with reference to the drawings, which are provided as illustrative examples of the invention so as to enable those skilled in the art to practice the invention. The present invention may be implemented using software, hardware, and/or firmware or any combination thereof, as would be apparent to those of ordinary skill in the art. The preferred embodiment of the present invention will be described herein with reference to an exemplary implementation with the Microsoft Windows™ Operating System(s). However, the present invention is not limited to this exemplary implementation, but can be practiced in any GUI based computer system.
As will be described in more detail, the invention provides a “shuffle” process and system that includes a method of controlling the order and placement of GUI windows on a computer PC desktop where a group of application windows is placed in a deck such that their title bars are visible at all times. Any window in the deck can be selected and brought to the front of the deck by clicking the mouse on its title bar, any exposed area of that window, or using a keyboard shortcut.
The window that is replaced as the active window in the deck is shuffled into another position in the deck as defined by a setup option to be either first-in-first-out order; or a round robin order where only the window that is clicked is shuffled with the windows below it. Window placements within the deck may be according to settable horizontal and vertical offsets and the invention includes the ability to “animate” the shuffling of the decks with settable on/off and speed of the animation.
A window may be removed from a deck by dragging the active window away from the deck. This automatically removes that window from the deck. A deck may be moved (dragged) around the display screen by dragging the title bars of any of the highest inactive window in the deck. This will cause the whole deck to be moved around the screen. In one embodiment, the deck can be split by grabbing the window at the split point and pulling that window and the windows below it in the deck away.
Windows may become part of a deck by dragging a window onto the deck so that the new window's title bar is placed within a settable defined pixel count of the current active window of that deck. In one embodiment, decks can be “decked” into other decks forming one larger deck by dragging the highest inactive window in the deck and dropping it on the target deck similar to adding a single window into a deck. Also, specific applications may be predefined to be part of an auto deck such that any instance created of such specified application automatically gets placed and positioned into the deck.
In one embodiment, the shuffle process employs special settable methods to make various “non-typical” window relationships compatible to the general capabilities. These include “Ignore Siblings” which causes sibling windows to not be shuffled; “No Resize” which inhibits window resizing for the specified application; “No Escape” for programs that use ESC to close to prohibit accidental closing; “Use Activation” a special case for programs that require the shuffler process to respond to windows that do not receive activation messages; “Check Visibility” which is used to handle multiple desktop programs correctly, primarily explorer; “Uses Owned Windows” for applications that create separate windows that they own that require shuffling implemented through a timer thread that checks for these new windows; “Allow Pop-ups” to be decked used in iE, for example, to allow download windows to be decked (WS_POPUP affected windows), and “Must Position” for applications that do not adhere to standard windows positioning commands which forces the display to adjust to the proper Z-order.
The invention also can handle MDI or “Multiple Document Interface” applications such that all the windows within an MDI application are controlled by the shuffler process; clicking on windows-cascade causes the windows to be decked, and resizing the main window automatically resizes the MDI windows (an option).
For purposes of example the Microsoft Windows™ Operating System(s) are used in the implementation examples and flow charts. It will be appreciated, however, that the invention is applicable to any of the existing GUI based operating systems.
In one embodiment, the shuffler process of the invention includes three main operational modules:
1—An executable or EXE which runs in its own program space and communicates back and forth with a DLL.
2—A dynamic link library or DLL which is dynamically loaded into existing applications that have top level windows on the desktop.
3—A setup program, a separate program that is used to customize the various properties and operational parameters of the invention. This program maintains XML files and sends a message to the EXE whenever it updates said XML files.
When a set of windows is cascaded together by the invention, this group of windows is described as being in a “deck”. The foremost (top) window in the deck is referred to as the active window. Any given application can be preset in the invention so that as new windows or instances of the application are started they are automatically added to an existing deck of that application. This is described as an auto-deck process. Auto-decks may be grouped together so that multiple applications can be automatically added to the same deck on the desktop. The invention also provides the ability to deck all applications on a desktop into one deck with one mouse click.
Further, another feature of the invention is the “multiple desktop aware” functionality. According to this feature, when software creates multiple desktops within the GUI, the shuffle process respects the sanctity of each desktop when making all its auto-deck decisions.
An example of the operation of the invention can be viewed in FIG. 1 , which shows three cascaded windows in a deck on a desktop display and the manner in which the deck may be shuffled to rearrange the deck by clicking a mouse on the title bars. The system and method of the present invention track and control various attributes and properties during this process. These properties are shown and discussed in the figures and tables below.
Table #1 of FIG. 2 contains examples of internal processing table properties that may be tracked for each window open in an application within the GUI. There can be many instances of these classes for any single process, dependent on how many top level windows the application opens.
Table #2 of FIG. 3 contains examples of internal processing table properties that are tracked for each Deck (both standard and MDI) that is currently managed within the GUI.
Table #3 of FIG. 4 contains examples of control table properties that are available for each different application (only if required) that changes that specific applications processing logic from the standard logic normally employed by the invention.
Table #4 of FIG. 5 contains examples of control table properties that are available for a specific window defined by that Window's title bar string as matching criteria. For example, features such as no resizing, no decking can be then applied to a specific window within an application.
Table #5 of FIG. 6 contains examples of control table properties that are available for a specific application to modify its behavior to be different from the default behavior as defined in Table #9 of FIG. 10 .
Table #6 of FIG. 7 contains exemplary data structures for each process running on the desktop with a top level window. And Table #7 of FIG. 8 contains exemplary data structures for each thread running on the desktop with a top level window.
Table #8 of FIG. 9 shows an exemplary MDI application data structure that holds the window handle of the MDI client window of an MDI application, one per MDI program instance.
Table #9 of FIG. 10 contains exemplary data structures describing global user settable parameters of the invention. And Table #12 of FIG. 11 contains exemplary data structures for describing the flags used for each client window being controlled by the invention.
Table #10 of FIG. 11 is an example of a properties table that may be associated with each attached DLL linked to a given Window. Various flags are updated from the main processing program into this table so the DLL has local access to them.
FIG. 12 is a table containing messages that may be employed by both the invention as well as the Windows Operating System to control the logic flow of the invention. FIGS. 13–17 detail each message and the logic employed by the invention for each message. The text within each message describes each message.
The present invention operates by hooking into a GUI based operating system at the individual application and thread level for each of the top level windows present on the desktop. The flowchart of FIG. 18 illustrates this startup process. As shown, step 1200 initializes the programs main settings at startup. Step 1201 registers the invention's inter program communication (IPC) messages required to operate between the EXE and DLL. Next, step 1202 loads the DLL. Step 1203 sets up a task bar entry, which is used by the users to make settings changes and exit the program. Step 1204 creates a worker thread that is used for special case applications as well as any MDI applications that might exist.
Step 1205 leading into step 1206 begins a scan for top level windows. Once a window passes the criteria of being a window capable of cascading, then the new window process, which is described below, is called. The loop continues via steps 1207 through 1209 until all top level windows currently on the desktop are processed. At this point step 1210 determines if any auto-decks were created by the previous routines. If there are decks that were created, then steps 1211 through 1214 are executed to perform the actual placement of each of the deck's windows into the cascaded arrangement. This process is shown in FIG. 19 as will be covered next. Once the process of FIG. 18 is completed, the startup of the initial invention process is complete and any further processing is initiated by user interaction with the GUI desktop as described below.
FIG. 19 shows the flow of a process that results in the actual shuffling process of each cascaded deck. Step 1601 first determines if the current mouse position needs to be saved. This is due to the possibility that a user clicked on an active area of the window he was activating (such as a link on an browser window) expecting a secondary action to take place. If this is the case, step 1602 saves the location information. Then after the shuffle has taken place and before that area is processed, the window would have been moved and, therefore, needs to be adjusted to compensate for the movement. Next, step 1603 determines if there is a new active window in the deck (step 1604 ). If not, then step 1610 determines if the shuffle order needs to be adjusted, in which case step 1612 adjusts the sequence of the windows (members) in the deck This adjustment is caused by another window being clicked on in the deck requiring it to be the new active window.
Next, step 1620 determines if the deck is actually visible on the desktop. If this is not the case then the process is done (step 1621 ). Otherwise, step 1625 is executed to calculate all the new adjustment offsets for each of the windows in the deck. Step 1630 determines if field 258 or 260 (Table #9, shown in FIG. 10 ) of the window are set, and if so, then the offsets are compared to the limits of the desktop and modified to maintain the deck position within the desktop (step 1631 ). This provides another feature of the invention, i.e., the selectable ability to limit the dragging of any deck off the desktop.
Next, steps 1640 through 1642 determine if a new mouse position is required for this shuffle. In this case, the mouse is moved to the new position. This is determined by whether the mouse click occurred on the title bar of the window or not. The new position is required if the click was not on the title bar.
Next, step 1650 calculates the new position of the active window. Then step 1652 checks field 264 (Table #9, shown in FIG. 10 ), or field 172 (Table #6, shown in FIG. 7 ) if this is an auto-deck to determine whether or not to use an animation feature to do the actual shuffling of the invention. The animation feature causes the movement of the window (Step 1654 ) to be stepped through a series of position movements or steps defined in field 270 (Table #9, shown in FIG. 10 ), causing the appearance that the window is animating its shuffle. This feature provides a user with a discernable visual cue as to what happens when the user clicks on a window in a deck. If no animation is requested, the step 1655 executes the direct new position of the window.
Next, the remaining windows in the deck may be repositioned in reverse order so that the sequence in the deck is consistent with a properly cascaded look and feel based on the new order of the windows in the deck. This is accomplished by steps 1660 to 1680 using similar logic to that by which the first window was moved in steps 1650 – 1655 .
When all of the windows in the deck have been moved to their new positions, then this process is completed (step 1690 ).
FIG. 21 shows the process that takes place whenever a new top level window is added to the desktop. Step 1300 retrieves the thread and process IDs; then step 1301 determines if this is a new process. If it is not, then Step 1320 looks up its Proc Instance and goes to Step 1321 . If it is, then step 1302 gets the name of the file that executes the application, and then step 1303 stores a new entry into Table #6 ( FIG. 7 ) Microsoft Windows™ Operating System(s) properties. Then step 1304 determines if the window is an MDI. If this is the case, step 1305 creates an MDI entry into Table #8 ( FIG. 9 ) properties, and then sets up a notification for the worker thread to watch this window (step 1306 ). Step 1307 then determines if this application has an auto-deck and if so, then step 1308 updates Table#8 ( FIG. 9 ) properties with the auto-deck ID. Step 1312 checks for an “owner window process”, which is an application that controls a set of separate windows through its own internal messaging system. If this is the case, then step 1313 sets up a worker thread notification for this condition.
If this is not an MDI application, step 1314 determines if there are program specific settings that need to be set for this new process. If this is the case, then Step 1309 updates the Table #3 ( FIG. 4 ) instance with the Program ID and Flags. Step 1310 checks to see if Auto Deck Settings are also required and if so Step 1311 Updates the Instance with Auto Deck Settings. Then the process goes to step 1321 for further processing.
If this process already existed, then its Table #6 ( FIG. 7 ) instance is located and then step 1321 determines if this is a new thread. If this is a new thread, then step 1322 creates a Table #7 ( FIG. 8 ) entry and adds this entry to a pointer list. Then step 1323 determines if the process and thread can be hooked to the DLL client and if this is the case step 1324 applies the hook. If it cannot be hooked, then the process is complete at that point (step 1327 ).
Step 1325 then continues with old threads and “hook able” new threads and determines if this new window is “deck able”. If this is the case, then the window decking process of FIG. 22 is called (step 1326 ). At this point the process is complete (step 1327 ).
FIG. 22 illustrates the logic that is used in the invention whenever a new application is launched onto the desktop. Step 1400 determines if the new application already has a defined auto-deck. If it does, then step 1401 determines if another instance of this application is on the desktop that is not in a deck, and steps 1403 through 1406 picks and sets the most recently active one of the deck and the stand alone application to be used in the decking process. Step 1407 then determines if it is the application that is most recent, and if this is the case, step 1408 creates a new deck. Step 1409 adds the found application to the deck and step 1410 sends a notification to the application that it has been added to the deck.
Step 1411 then determines if a deck has been found for the new application. If not, then step 1413 searches for another application on the desktop that matches the new application. In step 1414 , if none is found, the process ends at step 1450 . Otherwise, the process proceeds to step 1415 , and if the application was in a deck then the process continues at step 1430 below. If the found application was not in a deck, then a new deck is created in step 1416 and the found application is added to the deck in step 1420 and notified in step 1422 .
Step 1430 adds the new application into the deck. Step 1432 determines if the window can be resized and if so, step 1434 determines if the window is a different size than the windows already in the deck. If it is, step 1436 resizes the new window to match the windows already in the deck.
Step 1440 sends a notification to the application that the window has been added to the deck. Step 1445 calls the shuffle deck routine to position the deck correctly with the new window added. This completes the process (step 1450 ).
FIG. 20 describes a process that takes place when a window within the GUI is dragged and then dropped into a new location within the desktop. There are five basic possibilities (“cases”) that may affect this process whenever this type of event occurs:
1—The active window of an existing deck is moved.
2—A window that was part of an exiting deck but was not the active window is moved.
3—A window that is not in a deck is moved to the decking area of an existing window or deck.
4—A window that in not in a deck is moved to within the decking area of another window that is not in a deck.
5—A window is moved to a position on the desktop that does not meet any of the above criteria.
These are referred to as Cases 1–5 for purpose of explanation as to how the invention determines and treats each situation.
In step 1500 , the process determines the location of a dropped window. Steps 1502 and 1503 test if Case 1 is true. If true, step 1520 removes the window from the deck then proceeds to step 1522 . This is the beginning of the Case 3 process, since this window could have been removed from one deck and added to another deck in a single drag and drop operation.
The Case 2 process starts on the “no” side of step 1503 . In step 1505 , the process scans all the windows in the deck. Steps 1506 , 1510 , and 1512 through 1516 cause the other windows in the deck to be moved to their new locations on the desktop. If animation is on, step 1515 slides the window to its new location. If not, step 1516 moves the window to its new location without animation. Step 1514 decides whether the move should use animation based on the setting of field 265 . Once all the windows have been moved then the process is complete in step 1511 .
Cases 3–5 begin with step 1522 , where the process scans each deck to see if the moved window is within the range of an allowed deck. A deck may be defined as only allowing windows of the same application, as specified in field 170 . In this case, the applications must match between the deck and the window that has been dropped. If this is the case, as determined by steps 1530 and 1533 , step 1534 checks the location of that deck's active window. Step 136 then determines if the dropped window is within the range to be added to the deck. If this is true, then step 1540 is executed to add the window to the deck. Step 1542 determines if the window was in fact added to a deck. If this is the case, then step 1560 calls the shuffle deck operation to correctly arrange the deck on the desktop. Case 3 is complete in step 1562 .
The process tests for Case 4 starting with step 1544 , which begins a scan of all un-decked windows. Steps 1546 , 1550 and 1552 check the dropped window's location to each un-decked window to determine if the drop criteria is met as defined in field 255 . This criteria is the maximum number of pixels the top left corner of the dropped window can be away from each of the possible target windows. If the drop is within the specified pixel range, then the windows are deemed deckable, at which time step 1554 creates a new empty deck. Step 1555 adds both of the windows to this new deck. Then step 1560 is called to shuffle the deck and the operation is complete.
In Case 5, all the windows without a match are scanned. In step 1548 , the end of the window list is reached causing the last step 1562 to be executed, finishing the operation without actually doing any deck processing.
FIG. 23 shows the flow of automatic window resizing logic. Whenever any window in the deck is resized, then the rest of the windows in the deck are also resized to match the new window's size. The only exception to this is if a window is listed as non-resizable, in which case it is left alone.
Step 1700 calculates the offset adjustments, and step 1701 retrieves the position and size of the deck's active window, which is the new size. Step 1703 decides on whether animation effect is used in the resize. If this is the case, step 1705 slides the window to its new position. If not, step 1706 moves the window to its new position. These previous steps are executed to make sure the active window is on top and that everything is kept neat and organized within the deck.
Step 1710 starts the scan of all the remaining windows that may need to be resized. Step 1711 gets the next window from the deck, working in reverse order. Step 1715 determines if the loop is complete and ends with step 1718 if this is the case. Step 1719 calculates the new position of the window, and step 1720 checks to ensure the window being operated on can in fact be resized. Step 1722 changes the size of this window by the same size factors that the user made to the active window. Step 1725 determines if animation is active in which case the size change is animated in step 1727 . If not, the size change is made in one step in step 1730 and then step 1711 is executed again.
It has been determined through initial implementation of the invention using existing popular applications on the market that some applications operate and control their windows using different Windows messages and procedures other than the standards defined by Microsoft. This includes many of Microsoft's own popular applications. To facilitate the integration of such different applications into the invention's framework, the present method uses an integrated set of processes to overcome this potential problem. This will now be described.
FIG. 24 illustrates the operational flow of a process for integrating new applications, according to the present invention. Step 1800 starts the process by prompting the user to drag an information icon cursor to the window in question and click on the window. Step 1802 retrieves the window's handle, and step 1803 retrieves the process and thread IDs of the application running the window. Step 1804 then retrieves the program name of the application. Step 1810 determines if a program entry has already been established for this application in the settings file. If this is not the case, the settings files are updated with the program information (steps 1811 , 1812 ), and step 1813 sets up a link for other information to be added in the subsequent steps.
Step 1820 checks for an owned window by setting the owned window flag in step 1821 , and then asking the user to attempt to deck the window in step 1822 . Step 1825 determines if the deck was successful. If this is the case, the process is done (step 1827 ). If the application did not deck, then step 1826 clears the owned window flag.
Step 1830 checks for a popup window by setting the popup window flag in step 1831 , and then step 1832 asks the user to attempt to deck the window. Step 1835 determines if the deck was successful. If this is the case, then the process is done. If the application did not deck, then step 1836 clears the popup window flag. If the application did deck, the process is done (step 1837 ).
Step 1840 analyses a child window to see if the ignore siblings flag would help deck the window. Step 1842 checks the result of this analysis. If it is positive, then the ignore siblings flag is set in step 1844 . Then the user is asked to attempt to deck the window in step 1845 . Step 1846 determines if the deck was successful and if this is the case then the process is done (step 1847 ). If the application did not deck, then step 1849 clears the ignore siblings flag.
At this point we should note that the invention is not limited to the above-described checks and determinations, but as other types of windows become exposed to the application, then other checks and determinations can also be added. It will be apparent to those skilled in the art based upon the foregoing description as to the nature and manner in which such checks may be implemented and performed.
If none of the checks results in the application decking, then the user is prompted in step 1850 , if he would like to submit the application for analysis to a remote programming analysis facility. In step 1852 , if the answer is yes, the process proceeds to step 1853 and prompts the user to attempt to deck the window one last time. Step 1855 then captures all of the windows messages to a file. Step 1857 asks for the user's email address and step 1860 emails all the information to our support center for analysis. The process is then complete (step 1870 ).
Based upon the foregoing description and drawings, it will be apparent to those skilled in the art that well know programming techniques may be employed to create software for various computer architectures on which the invention is implemented. Moreover, while the invention has been described with reference to a particular embodiment and in connection with conventional Microsoft Windows™ operating systems, it will likewise be apparent to those skilled in the art that the invention has greater utility and may be implemented on other GUI-based systems having different architectures and running different operating systems.
Although the present invention has been particularly described with reference to the preferred embodiments thereof, it should be readily apparent to those of ordinary skill in the art that changes and modifications in the form and details may be made without departing from the spirit and scope of the invention. It is intended that the appended claims include such changes and modifications.
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The present invention provides a method and system of maintaining and controlling the ordering and placement for display of individual GUI windows into groups or “decks” similar to a deck of playing cards on a desktop area of a computer display. The decks comprise collections of cascaded windows. The method and system control the decks such that the title bars of all windows of the deck are always simultaneously visible to the user no matter which window is selected as the active window. The act of moving the current top window back into a new position in the deck is defined as “shuffling” the windows. The method and system further provide auto-deck processes that automatically cascade defined applications, such as Internet Explorer windows, into a deck. In addition, the method and system may also include user-definable options as to the order of the shuffle, and includes the ability to drag the active window out of the deck and to drag any window into the deck. Also, the method and system may allow for the automatic resizing of all windows in a deck by just resizing the active window, and for a predetermined grouping of different applications into the same deck.
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BACKGROUND OF THE INVENTION
The present invention refers to a roller press comprising a press roll and one or two cooperating pressure rolls, with particular application to a paper machine press section.
A roller press of this type is taught in Federal Republic of Germany Patent No. 959,702, corresponding to U.S. Pat. No. 2,855,829. It is there combined with a press section in a machine for the manufacture of paper and cellulose webs. In general, a roller press of this type can be used in wet presses and calenders and paper-making machines, as well as in plastic calenders and rolling mills.
In a known roller press or plant for the production of paper and cellulose webs, there is a pressure roll which is intended to be pressed against a fixed suction roll and there is a device for automatically lifting the pressure roll off the suction roll. Such lift occurs when the pressure prevailing in the suction line of the suction roll exceeds a given working pressure during the operation of the roller press, i.e. the required vacuum is no longer present in the suction line. The pressure roll is connected with a pressure cylinder which is finally activated when drying of the web of paper is no longer assured.
Brief variations in pressure are not recognized or responded to in the known design. In particular, disturbances on the suction roll which are limited in space are not recognized since measurements of the amount of air in the suction lines are too inaccurate for recognizing such deviations. For instance, entrained foreign bodies or folded regions of a pulp drainage felt, which are traveling through the press nip between the suction roll and the pressure roll, go unrecognized. For dependable operation of such a roller press and for the protection of the expensive roll coverings and pulp drainage felts, it is important that even brief, minor disturbances be rapidly and dependably recognized.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a roller press in which even relatively small disturbances are recognized, preferably rapidly. Another object is that as a result of these recognized disturbances, the press nip is immediately relieved of load over its entire width and, if necessary, the nip may also be opened.
The roller press of the present invention is shown in two embodiments, one that works hydraulically with working fluid and the other that is electrically operated. In all embodiments, the roller press includes a press roll. Means fix the press roll in position, but enable it to rotate. At least one pressure roll is arranged parallel to the press roll. The press and pressure rolls have respective surfaces that press against each other.
A plurality of positioning cylinders is associated with each of the pressure rolls for displacing the pressure roll with respect to the press roll so that the surfaces press together or move apart in a direction transverse to the axis of the pressure roll. There are operating means connected with each of the positioning cylinders for operating the cylinders to separate the pressure roll from the press roll as a result of a disturbance in the pressure at any of the positioning cylinders. That disturbance would occur upon some anomaly in the press nip. That operating means comprises a respective safety valve connected with each positioning cylinder. The safety valve is operated by the respective positioning cylinder to a valve open condition for relieving pressure in the positioning cylinder upon the disturbance in the press nip. Connecting means functionally connect all of the safety valves with each other. Upon an increase in the pressure in one positioning cylinder, which causes the opening of its respective safety valve, all of the safety valves correspondingly move to the open condition so that all the pressure cylinders are relieved.
In one preferred embodiment, there are two of the pressure rolls. Each of the pressure rolls has a respective plurality of the positioning cylinders, each provided with a respective safety valve. All of the safety valves for all of the pressure rolls are connected together for relieving pressure if the pressure increases in any of the positioning cylinders.
In one embodiment, the safety valves have a fluid connection to the respective positioning cylinder and are operated by over-pressure in the positioning cylinder. In another embodiment, all the safety valves are electrically operable. Over-pressure in any positioning cylinder operates the valve electrically to the valve open pressure relief condition. All of the safety valves are here electrically connected to each other to operate together.
There is a main control valve connected with a source of working fluid which pumps the positioning cylinders to operate and that valve is also connected with the positioning cylinders of each respective pressure roll and with the respective safety valves of the respective pressure rolls. Closing of the main control valve from the source of working fluid prevents the passage of working fluid to the positioning cylinders and thereby triggers the closing of the safety valves to the non-relief conditions. There are closing means in the safety valves for closing the safety valves, upon the closing of the main control valve against flow of working fluid from the main control valve to the safety valves.
Where the pressure roll is above the press roll, the pressure roll rests with its own weight upon the press roll. The safety valve is connected with the respective positioning cylinders for causing the positioning cylinders to raise the pressure roll off the press roll.
The safety valve comprises a valve housing having a cylindrical chamber in it in which the valve body is movable. The valve body has opposite first and second active surfaces and there is a first pressure space above the first surface and the second pressure space below the second surface. The first pressure space is connected with the positioning cylinder to be acted upon directly by the pressure in the positioning cylinder. The second pressure space communicates with the positioning cylinder through a throttle. A spring acts upon the valve body for moving the valve body in the same direction as the pressure applied to the second surface of the valve body.
The connecting means between the various safety valves comprises a signal line connected to the second pressure space of every safety valve for connecting the second pressure spaces, whereby relief of the second pressure space of one valve relieves the second pressure space of all of them. An outlet relief connects to any one of the second pressure spaces, whereby relief of one pressure space relieves all. The valve bodies are arranged so that an increase in the pressure in one of the positioning cylinders moves the respective valve body for that cylinder to the position for relieving the pressure in the respective second pressure space and through the signal line connects all of the second pressure spaces for relieving them. The valve bodies are further designed so that upon shifting of the valve bodies upon relief of the second pressure spaces, the valve bodies have a further connection to the respective first pressure spaces.
The return spring has a force adjusted so that at a predetermined pressure in the positioning cylinder, the first and second active surfaces are in equilibrium with the respective safety valve in the valve closed, non-relieving position. The ratio of the first and second active surfaces is in the range of about 1.02 to 1.2 for the first active surface to 1 for the second active surface.
The first pressure space in the safety valve has a first outlet while the second pressure space has a second outlet. These outlets are arranged and dimensioned relative to each other and to the valve body that after relief of the working pressure in the second pressure space, the first outlet from the first pressure space is opened to an extent that the pressure acting on the first pressure surface is equal to the force being exerted by the return spring.
The valve housing of the safety valve contains a valve body that is actually comprised of two closed cylinders, with each of the cylinders having one of the active pressure surfaces defined on it. A first inlet into the valve housing communicates into the first pressure space while the second valve inlet into the valve housing communicates into the second pressure space. The throttle comprises a throttle line between the first and second inlet bores. The housing also has outlet bores from the first pressure space and from the second pressure space for communicating to the outlet relief. In particular, the first cylinder comprises a hollow shell and the second cylinder also comprises a hollow shell and the communications from the first and second cylinders to the respective outlets is through openings through the respective hollow shells.
In the alternate electrical embodiment, each of the safety valves comprises an electromagnetically actuated valve which is normally closed in a first operating position and which communicates with the positioning cylinder and also with a relief for pressure. The safety valve has one operating position in which it is closed against relieving pressure from the positioning cylinder to the outlet relief. The safety valve has a second position which connects the positioning cylinder to the outlet relief for relieving pressure in the positioning cylinder. A pressure switch electrically connects the safety valve and is operatively connected with the positioning cylinder. Upon an increase of pressure in the positioning cylinder, the pressure switch is operated for operating the safety valve to switch between the first closed position and the second pressure relief position.
An electric relay electrically connects all of the safety valves and is switched to operate by the signal which switches any of the safety valves from their first to their second positions. The relay includes a switch for being reset for enabling the connected safety valves to be reset into their first positions.
Other objects and features of the present invention will become apparent from the following description of the preferred embodiments of the invention considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 diagrammatically shows a three-roll wet press;
FIG. 2 diagrammatically shows the hydraulic circuit for the three-roll wet press of FIG. 1;
FIG. 3 diagrammatically shows one of the safety valves shown in FIG. 2, in its second switch position;
FIG. 4 is a cross-section showing the structural development of one of the safety valves shown in FIG. 2;
FIG. 5 diagrammatically shows a second embodiment of the hydraulic circuit for a two-roll press.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a so-called three-roll wet press, for example, that shown in Federal Republic of Germany Patent No. 1,090,076, corresponding to U.S. Pat. No. 2,869,437. For reasons of clarity of the drawing, the drainage felts, the paper web to be dried as well as guide rolls, frame elements and other mechanical structural parts of the press are not shown.
The three-roll wet press 1 comprises a press roll 3, which is mounted in a fixed position in stationary supports 2, and two pressure rolls 4, 5 which can be applied tangentially against the press. The longitudinal axes of the press roll 3 and the pressure rolls 4, 5 lie in the same plane, and the pressure rolls lie on opposite sides of the pressure roll.
One pressure roll 4, the lower one in FIG. 1, is applied against the press roll 3 from below, in opposition to its weight, by a first pair of levers 6, 7. A second pressure roll 5 is applied against the press roll 3, aided by its own weight, from above by a second pair of levers 8, 9. Each of the levers 6, 7, 8 and 9 is pivotally mounted in a fixed support at one end of the lever and is turnably connected at the other end of the lever to the respective ends of the pressure rolls 4, 5.
Respective positioning cylinders 10, 11, 12 and 13 actuate or move the individual levers 6, 7, 8 and 9. The pressure rolls 4, 5 are thereby pressed with the necessary pressing force against the press roll 3. The pressing force between the pressure rolls 4, 5 and the press roll 3 is determined by the working pressure in the respective positioning cylinders 10, 11, 12, 13.
Referring to FIG. 2, each of the positioning cylinders 10, 11, 12, 13 has a respective pair of inlets 101, 102; 111, 112; 121, 122; 131, 132 for the working fluid, e.g. oil, which acts upon the piston top and the piston rod sides, respectively, of the respective operating or lift pistons. Fluid applied at the inlets brings the working pistons into the correct working position or to the correct pressing pressure. In the three-roll wet press 1 shown in FIG. 1 as well as in the two-roll press to be described with reference to FIG. 5, each pressure roll has a positioning cylinder associated with each of its ends so that the pressing force, i.e. the working pressure, between press roll and pressure rolls can be precisely adjusted over the entire width of the roll section (length of the pressure roll).
The invention comprises associating a safety valve with each of the positioning cylinders through which an increase in pressure which is sensed in a positioning cylinder and which is due, for instance, to a disturbance in the press nip between one of the pressure rolls and the press roll, causes relief of the working pressure of this positioning cylinder and also of the other positioning cylinders.
Each positioning cylinder 10, 11, 12, 13 is associated with a respective lever 6, 7, 8, 9, which acts on the ends of the pressure rolls in such a manner that the positioning cylinders 10, 11 correspond to the one pressure roll and the positioning cylinders 12, 13 to the other pressure roll.
FIG. 2 diagrams the hydraulic system of the three-roll wet press. The positioning cylinders 10, 11 are paired and 12, 13 are paired with each other. The paired cylinders have inlets 101, 111 and 121, 131, respectively, connected in each case jointly to a main control valve 20 and 21, respectively. Via the main control valves 20, 21, the positioning cylinders 10, 11 and 12, 13 can be connected to oil pumps 22 and 23, respectively, which provide the positioning cylinders 10, 11 and 12, 13, respectively, with the required working pressure via their inlets 101, 111 and 121, 131, respectively.
Each positioning cylinder 10, 11, 12, 13 has associated with it a respective safety valve 24, 25, 26, 27, which is designed so that upon an increase in pressure in the corresponding positioning cylinder 10, 11, 12, 13, i.e. upon the occurrence of excess pressure, the respective safety valve immediately relieves the pressure in its positioning cylinders 10, 11, 12, 13. The safety valves 24, 25, 26, 27 of one press section are coupled so that an excess pressure in the corresponding positioning cylinder 10, 11, 12, 13, which is sensed in one of the safety valves 24, 25, 26, 27, is simultaneously conducted to all the other safety valves 24, 25, 26, 27 of the same press section. The other safety valves then also relieve the working pressure of the corresponding positioning cylinders 10, 11, 12, 13. Excess pressure in one positioning cylinder 10, 11, 12, 13, due, for instance, to a disturbance in the neighboring press nip, thus relieves all of the positioning cylinders of load. Referring to FIG. 1, this means that the lower pressure roller 4 moves downward under its own weight and opens the press nip. If the upper pressure roll 5 is also to be lifted off the press roll, i.e. the upper press nip is to be opened, the corresponding positioning cylinders 12, 13 must be acted upon on the piston rod side. In addition, still other functions, such as, for instance, the stopping of the press drive, can be initiated by a work signal which is generated in one of the safety vales 10, 11, 12, 13 as a result of a condition of excess pressure.
The manner of operation and the structural development of a safety valve 24, 25, 25, 27 is now discussed. The safety valve 24 is typical of valves 25, 26, 27. Valve 24 has two line connections a, b on its inlet side. It also has an axially movable valve body 30 schematically shown as vertically movable in FIG. 2. On its outlet side, there are two connections 34, 35. These are both connected to a relief line 33 which extends to an oil collecting pan. The movable valve body 30 has a first, larger end surface A1 and a second, opposite, somewhat smaller end surface A2. The first end surface A1 and the connection a are connected to the inlet 101 of the cylinder 10 and are therefore directly acted upon by the working pressure in that cylinder. The second, smaller end surface A2 and the connection b are also connected to the inlet 101 of the cylinder 10, but via a throttle 31. The dashed arrow line from line 36 to surface A2 shows how surface A2 is acted upon. The second end surface A2 is, in addition, acted on by the force of a spring 32. In the static condition, i.e. as long as no working fluid or oil flows through the throttle, the pressure on the surfaces A1 and A2 is the same.
In FIG. 2, the valve bodies 30 of the safety valves 24, 25, 26, 27 are shown against the upper stop. Thus, the communications to the relief line 33 are interrupted, i.e. closed. To couple the safety valves 24, 25, 26, 27 of a press section to each other, the second end surfaces A2 of all safety valves 24, 25, 26, 27 are connected to each other via signal lines 36. In the event of an impermissible increase in the working pressure in one of the positioning cylinders, for example cylinder 10, the increased pressure on the end surface A1 of the safety valve 24 displaces the valve body 30 in the "open" direction toward the bottom in FIG. 2. This relieves the pressure present at the smaller end surface A2 of the valve body of the safety valve 24 by connecting the two connections b and 35. The signal line 36 at the valve 24 is relieved also through such connections. At the same time, the smaller end surfaces A2 of the other safety valves 25, 26 and 27 are also relieved via the connected signal lines 36, so that the valve bodies of the other valves also shift down and the other valves are also open. As a result, the respective inlets 101, 111, 121, 131 of all of the valves are connected to the relief lines 33 on all positioning cylinders 10, 11, 12 and 13.
The switchable connections between the pressure-side connections a, b and the outlet-side connections 34, 35 are indicated by the solid arrows in the valve body 30. Due to excess pressure or because of the difference in pressure on the first end surface A1 and the second end surface A2, if the valve body 30 is displaced against the force of the spring 32, out of the equilibrium position and toward the bottom in the drawing, then the first passage b-35 corresponding to the lower arrow is opened first, which permits the pressure on the second end surface A2 to drop toward zero. The valve body 30 is then pushed down further and with increased force so that the second passage a-34 corresponding to the upper arrow also opens, while the first passage b-35 remains open.
The force of the spring 32 is so adjusted that, slightly below the threshold or difference value which triggers the start of the switching process of a safety valve 24, 25, 26, 27, the setting forces acting on the two end surfaces A1 and A2 are in equilibrium with each other. The force of the spring 32 corresponds in this case to the product of the difference in area of the end surfaces A1 and A2 times the working pressure. With this adjustment of the force of the spring 32, the valve body 30 of each of the safety valves 24, 25, 26, 27 "floats" in an intermediate position, which is still closed. The valve body thus has a very short reaction time, i.e. switching time. In order to be able to use small spring forces, the ratio between the two end surfaces (effective surfaces) A1 and A2 is only slightly greater than 1, and preferably between 1.02 and 1.2 for the surface A1 to 1 for the surface A2.
Once any safety valve 24, 25, 26, 27 has opened, the communication between the connection a of the working pressure and the relief line 33 remains open only to such an extent that the residual force acting on the first end surface A1 corresponds to the force of the spring 32. By this structural solution, the connection of the signal line 36 to the relief line 33 is finally held open. Thus, there is no possibility that the working pressure at the positioning cylinders 10, 11, 12, 13 will unintentionally build up again. This is necessary to assure that the working pressure does not build up before the cause of the increase in pressure has been recognized and eliminated.
In order to reach the normal working condition again, i.e. have working pressure available at all positioning cylinders 10, 11, 12, 13, the main control valves 20 and 21 must first be brought into their zero positions. In this way, the pressure acting on the first end surface A1 is brought to zero and the valve bodies 30 of the safety valves 24, 25, 26, 27 are pushed by the force of their springs 32 into the closed position until the valve bodies 30 again lie against their upper end stops. The main control valves 20, 21 can now be opened, i.e. the positioning cylinders 10, 11, 12, 13 can again be acted upon by working pressure.
The through switched condition of the safety valve 24, 25, 26, 27 will be described with reference to FIG. 3. In this switching condition, both the inlet a on the working pressure side and the second inlet b coupled via the throttle line 31 are in communication with the relief line 33. The connection of the inlet b to the relief line 33 is entirely open. Between the working pressure line a and the relief line 33, there is a throttled connection, since the force of the spring 32 maintains the equilibrium. This means that the pressure liquid conveyed by the oil pump 22 or 23 flows in part over the working pressure side connection a and in part over the throttled connection b to the relief line 33.
The structure of a safety valve 24, 25, 26, 27 is explained with reference to FIG. 4, which is a longitudinal section through the valve. The safety valve includes a valve block 37 within which the valve body is contained for axial movement within a central bore 38. In FIG. 4, the valve body 30 is in so called "floating" equilibrium, which it assumes when the working pressure is slightly below the predetermined trigger or limit value set. This limit value is preferably selected so that the difference between the pressure at which the valve body lifts off the upper end stop and at which the pressure relief commences is, for instance, 5% of the maximum permissible pressing pressure between pressure roll and press roll.
The valve body 30 is actually comprised of two cylinders 39, 40, each of which is closed at one side so that they together define two closed end surfaces, which correspond to the active surfaces A1 and A2, respectively, of the safety valves 24, 25, 26, 27 in accordance with FIGS. 2 and 3, resting against each other. The "upper" cylinder 39 has a larger diameter A1. There is access from the open side of the upper cylinder 39 to the working pressure line a. The "lower" cylinder 40 has a smaller diameter A2. There is access from the open side of the lower cylinder 40 to the inlet b which is connected via the throttle line 31 to the working pressure line a.
In another embodiment (not shown), the two cylinders 39, 40 can also be combined into a single piece valve body 30. Instead of the throttle line 31 arranged in the housing 37, a coaxial throttle bore can then be provided in the valve body 30.
The lower cylinder 40 is resiliently mounted via a spring 32. The force of the spring 32 is adjustable from the outside by a bolt 41 which is axially displaceable coaxial to the central bore 38. The bolt 41 has a support disk 42 which corresponds to the diameter of the spring 32 and which can be displaced axially via a bolt 43 to adjust the spring 32 to the predetermined spring force.
Both cylinders 39, 40 have respective openings 39', 40' distributed over their peripheries. Paths to the relief line 33 can be opened through the openings 39', 40'. For forming these paths, two annular spaces 34, 35 are worked into the valve block 37 for the connections. Both of the spaces 34, 35 have a connection to the relief line 33, as shown in FIGS. 2 and 3. The arrangement of the annular spaces 34, 35 and their association with the openings 39', 40' is such that, upon an axial movement in the direction of arrow X of the valve bodies 30, i.e. of the two cylinders 39, 40, first the openings 40' of the cylinder 40 having the smaller effective-surface/end-surface A2 are connected to the lower annular space 35. Upon further displacement of the valve bodies 30, the connecting line between the working pressure line a and the relief line 33 then also opens via the openings 39' while the connection of openings 40' at space 35 remains.
The interaction with respect to the spring force and the consequence of the opening of the line paths a and b to the low pressure line 33 has already been explained with reference to FIGS. 2 and 3.
A second embodiment of the invention is explained below with reference to a two-roll press shown in FIG. 5. In contrast to the embodiments of FIGS. 2, 3 and 4, FIG. 5 concerns an electrical system. It has the advantage from the start that the propagation of the signal is very much faster, which can be important with respect to rolls having a width of up to ten meters.
For each pressure roll, there are two positioning cylinders 10, 11, each having a respective associated electromagnetic safety valve 50, 51. To transmit a signal in the event that the working pressure in one of the positioning cylinders 10, 11 increases to an impermissible extent, a respective electric pressure sensing switch 52, 53 is arranged on each positioning cylinder 10, 11.
If one of the pressure switches 52, 53 closes as a result of an impermissibly high pressure in its respective positioning cylinder 10, 11, then the electromagnets of all safety valves 50, 51 are energized via the corresponding switch signal as a work signal when those valves are coupled with respect to the signal. At the same time, the safety valves 50, 51 are are thereby brought into an operating position which switches open a connection to a low-pressure connection, for instance of an oil collection pan.
Referring to FIG. 5, each safety valve 50, 51 has an inlet connection c. These connections c are connected to the working pressure side connection of the positioning cylinders 10 and 11, respectively, and, via a main control valve 54, to an oil pump 55. The safety valves 50, 51 comprise respective valve bodies 56 and 57, which are held by the force of respective setting springs 60, 61 in a first closed pathway operating position. In this first operating position shown in the drawing, the connection to be switched by each valve body is closed.
The electromagnets 58, 59 may be supplied with electricity via electric line 63 from a voltage source 62. The electromagnets 58, 59 are connected via a signal line 64 to each other and to the pressure switches 52, 53. If either pressure switch 52, 53 is closed due to elevated pressure, then the electromagnets 58, 59 are energized. The valve bodies 56, 57 are then pushed (up in FIG. 5) into their second open pathway operating position against the setting springs 60, 61. As a result, the inlet connection a from the cylinders 10, 11 is connected to the lowpressure line. The working pressure at both positioning cylinders 10, 11 together thus drops to zero. Of course, the switching movement can also be reversed such that the electromagnets are energized in order to close the valves while they are cut off from current to open the valves when there is an overload signal.
As already explained based upon FIG. 2, the working pressure must be prevented from again building up prematurely in an undesired manner. For this purpose, a holding circuit is integrated in the circuit, to assure that the safety valves 50, 51 remain in the open condition, which is their second operating position. This holding circuit comprises a relay 65 which is in parallel with the circuit of the electromagnets 58, 59 of the safety valves 50, 51 and can be so acted upon via a switch 66 which can be switched to ground potential that the electromagnets 58, 59 are energized and the valve bodies 56, 57 are pulled against the force of the setting springs 60, 61 into the first or closing operating position. Now working pressure can again be built up at the positioning cylinders 10, 11 via the main control valve 54.
Although the present invention has been described in connection with a plurality of preferred embodiments thereof, many other variations and modifications will now become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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A roller press has a press roll and at least one pressure roll applying pressure to it. In the end region of each pressure roll, there is an associated positioning cylinder. The positioning cylinders relieve the pressure of the pressure roll against the press roll automatically upon an impermissible increase in the operating pressure in the positioning cylinder. For this purpose, each positioning cylinder has a safety valve which is operated either by the working fluid in the positioning cylinder to the pressure relief condition or by an electrical signal, in different embodiments, to relieve pressure in the positioning cylinder. The safety valves are coupled to each other by a signal line. When one safety valve relieves one positioning cylinder, all of the positioning cylinders are relieved. Details of the working fluid operated safety valves and of the electrically operated safety valves are disclosed, including details of the valve body and the application of pressures upon the valve bodies which causes them to shift.
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BACKGROUND OF THE INVENTION
In the production of continuous glass filaments, it is the general practice to apply a liquid size or binder to the advancing array of filaments as they are pulled from the bushing before being gathered into a strand or strands. Some of these size applicator systems incorporate a rotatable roll for transferring the liquid from a reservoir to the advancing filaments.
It is, generally, necessary to maintain a fresh supply of size and/or binder in the reservoir associated with the roll to apply a suitable coating to the filaments. As such, an excess of liquid is generally supplied to the reservoir during operation. Yet, economic and safety considerations dictate that the excess liquid be collected and recycled if at all possible.
U.S. Pat. No. 4,015,559 issued to Sears et al. on Apr. 5, 1977, discloses an applicator system wherein a dual tray or reservoir assembly is employed in a roll type applicator for collecting and recirculating the excess liquid. The instant invention modifies the dual container aspects thereof to improve the operating characteristics of such applicators.
SUMMARY OF THE INVENTION
Apparatus is provided for applying liquid to filaments comprising: a movable surface adapted to supply said liquid to said filaments; a first container adapted to supply said liquid to said applicator surface, said first container comprising a bottom wall, a front wall having an upper edge extending along the length of said surface, a rear wall having a vertically oriented flow control means, the lower edge of said control means extending below said bottom wall, the upper edge of said control means being lower than the upper edge of said front wall; and a second container adapted to accommodate said first container to receive said liquid moving along the exterior of said first container, said second container having a forwardly angled front portion, a rear portion, side portions, and baffle means intermediate said sidewalls, said baffle means having at least one recess therein to permit said liquid to pass therethrough while retaining sinkable or settleable foreign matter within a settling zone formed between said baffle means and one of said sidewalls and while retaining floatable foreign matter within said zone, said flow control means being positioned to direct excess fluid moving therethrough into said settling zone.
An object of the present invention is to provide an improved system for applying liquid to advancing filaments.
The foregoing, as well as other objects of the present invention, will become apparent to those skilled in the art from the following detailed description.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a frontal view of a size applicator according to principles of the present invention.
FIG. 2 is a sectionalized side view of the applicator shown in FIG. 1.
DESCRIPTION OF THE INVENTION
As shown in FIGS. 1 and 2, size applicator assembly 10 is adapted to supply liquid size and/or binder 6 to the array of advancing filaments 8 as is known in the art.
Applicator 10 is comprised of housing 12 having an application surface or roll 14 rotatably journaled therein at shafts 15 extending from roll 14. It is to be understood that the application surface can be a belt type applicator as well as a roll type applicator.
Roll 14 is driven by motor 17 by means of pulleys 18 and belt 19. Generally, the roll is driven such that the surface of the roll 14 in contact with the filaments 8 is moving in the same direction as the filaments. However, in some instances the roll can be driven counter to the advancement of the filaments.
First container 22 is mounted with respect to housing 12 and roll 14 such that during operation the surface of roll 14 is partially immersed in the body of liquid 6 in container 22.
First container 22 is comprised of a front wall 24 having an upper edge 25 extending along the length of roll 14, a bottom wall 27, sidewalls 29, and a rear wall 31 suitably joined together to form a reservoir for holding liquid 6. First container 22 also includes a vertically oriented liquid flow control channel means 33 comprising a plate 34 attached to rear wall 31 and a pair of bars projecting laterally beyond the exterior surface of plate 34 to form the channel. Channel means 33 is oriented such that the upper lip 36 thereof is positioned in a horizontal plane below the upper edge 25 of front wall 24.
As shown in FIG. 1 a pair of channel means 33 are located at the rear wall 31. In operation, as an excess of liquid 6 is supplied to first container 22 at liquid inlet port 38 located in one of the sidewalls 29, the excess liquid flows over the upper lip 36 of channel means 33 and downwardly into settling zone 72 of second container 50.
Second container 50 is adapted to slideably receive first container 22 and to capture the excess liquid from first container 22 and any spray thrown from the filaments or the like deposited on the front wall 24 of first container 22. Second container 50 is mounted within housing 12 by positioning means 80.
Second container 50 is comprised of a front portion 52 extending outwardly or forwardly from bottom portion 55 joined thereto. Second container 50 also includes side portions 57, one of which has recess 58 located therein to accommodate inlet tube 85 joined at liquid inlet port 38 of sidewall 29 of first container 22.
Each side portion 57 has a projection 59 extending inwardly toward each other adapted to accommodate each of the sidewalls 29 such that securement means 68 positions the sidewalls 29 against projections 59 to adjustably locate first container 22 within second container 50.
Baffle means 64 which is comprised of plate 65 securely joined to front portion 52, bottom portion 55, and rear portion 61 of container 50 divides the lower region of the second container 50 into a settling zone 72 and an outlet region 73.
Plate 65 has a serrated upper edge 66 comprised of a plurality of slots or recesses 67 along the length thereof. Perferably, the slots are approximately 1/16 inch wide and extend from the top edge of plate 65 to within about 1/8 inch from the bottom edge of plate 65 adjoining bottom portion 55 and are about 1/4 inch apart along the length of plate 65. This permits contaminants in the excess liquid delivered to zone 72 to collect in the settling zone beneath the lower edge of the slots 67 if the contaminants have a density greater than the density of the liquid 6 (i.e., sinkable). During operation, floating foreign matter can also form on the surface of liquid 6 in settling zone 72. The serrated upper edge 66 provides a means for retaining the floating matter within the zone and yet permit the liquid 6 to flow into the outlet region 73 to outlet tube 87 through outlet 74 located in bottom portion 55. Thus, the sinkable and floatable foreign matter or contaminants are retained in the settling zone 72 for periodic removal by the operator. Thus, the foreign contaminants are removed from the excess liquid before being recycled.
First container 22 is positioned within second container 50 such that the upper rim 53 of front portion 52 extends outwardly beyond the junction of the front wall 24 and bottom wall 27 to collect any excess liquid flowing down front wall 24. Also first container 22 incorporates a handle means 40 comprising a pair of curved bars adapted to direct any liquid on the handle means along the front wall 24 and/or into the second container 50. The handles 40 are adapted to provide the operator with a convenient means for removing, inserting and adjusting the first container 22 in second container 50.
Securement means 68, which urges the sidewalls 29 into projections 59 to frictionally retain the first container 22 in second container 50, is comprised of a boss 69 on bottom portion 55 having a threaded hole 70 to receive screw 77 which is adapted to contact bottom wall 27 and urge first container 22 upwardly into projections 59. It is preferred that the bottom wall 27 have a boss or landing section to receive screw 77. Screw 77 is locked into place by any suitable means such as locking nut 78.
As shown in FIG. 2, positioning means 80 for locating second container 50 within housing 12 is comprised of a shaft extending along the length of second container 50. Shaft 81, which is rotatably mounted in housing 12, has an eccentric cam 82 thereon such that as arm 83 of shaft 81 is rotated, the surface of cam 82 urges the second container 50 into fixed engagement with housing 12.
It will be appreciated that variations in constructional features as well as substitution of equivalent components and methods can be undertaken without departing from the spirit and scope of the present invention.
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Apparatus for applying liquid to advancing filaments is comprised of a pair of nestable containers having specific liquid control portions for improved excess liquid capture and recycling.
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FIELD OF THE INVENTION
[0001] The present invention relates to a combined space-cooling and irrigation system.
BACKGROUND
[0002] Ground temperatures four feet below grade are a constant 50° F. to 56° F. from the east coast of North America to the west coast and from Atlanta Ga. to Sudbury, Ontario. This vast area has cool ground temperatures and hot summers with attendant cooling and irrigation requirements.
[0003] Cooling systems which make use of the relative coolness of underground water sources, such as wells or municipal water mains, are well known in the art. For example, U.S. Pat. Nos. 4,375,831, 4,946,110, 5,727,621, 6,041,613 and 6,688,129 disclose the concept of using the coolness of ground water to acclimatize living space. Also known in the art are systems for controlling irrigation, for example, U.S. Pat. Nos. 4,134,269, 4,393,890 and 4,693,419. However, none of the above patents combine a space cooling system, which makes use of underground water for cooling needs, with an irrigation system.
[0004] U.S. Pat. No. 5,140,829 to Barwacz teaches a space-cooling system using a heat exchanger for ground water that has been slightly chilled by a heat pump. The heat pump cools the incoming ground water and uses the return flow of warmed ground water, or at least a portion of the return flow, to evaporate the heat pump's refrigerant gas. The heated discharge water can be used as pre-heated household water, or discharged for irrigation or to a drainage system. Barwacz therefore discloses the use of ground water for heat exchange purposes and then using the water for irrigation or household uses. However, there is no disclosure of a closed loop cooling system that would allow for humidity control. Furthermore, there is no teaching concerning a balancing of irrigation needs and cooling needs.
SUMMARY
[0005] The present invention provides a system that makes use of the relative coolness of underground water for cooling needs when the water is needed for irrigation in any event.
[0006] It is an object of the present invention to provide a system that reduces electric energy consumption for cooling purposes by making use of the relative coolness of the ground water that is used for irrigation purposes.
[0007] It is another object of the present invention to provide a system that warms water to be used for irrigation purposes.
[0008] It is another object of the present invention to provide an integrated irrigation and cooling system that operates automatically.
[0009] It is another object of the present invention to provide a system that reduces electric energy consumption for cooling purposes by making use of cool external temperatures
[0010] It is yet another object of the present invention to provide a closed loop cooling system that allows for humidity control.
[0011] The above objectives are accomplished by a novel irrigation reservoir cooling system and method of operation. The system is operated by an automated control unit specifically programmed to manage cooling and irrigation needs generally as follows.
1) When space cooling is needed, for example, during the solar heat gain of the day, the system pumps cool underground water (ground water) from a pressurized municipal (city) water supply, a well, or a deep pond, through a heat exchanger on the way to a reservoir. The water is pumped (transported) by providing the system with a water pump or by connecting the system to a pressurized municipal water supply. 2) The water pumped through the heat exchanger cools fluid in a separate closed circuit. The closed circuit includes at least one fluid chiller, which is sufficient to provide cooling when irrigation water is not needed, for example, during the night, on rainy days or in the winter. 3) The cooled fluid in the closed circuit is then used for cooling purposes, for example, to cool the air circulated through a house or building using a commercially available fan coil unit. 4) The reservoir releases collected water for irrigation purposes at appropriate times, normally at night.
[0016] The irrigation reservoir cooling system is ideal for cooling buildings that use irrigation systems such as estate homes and golf and country clubs.
[0017] In one embodiment, the system is provided with a secondary heat exchanger to further exploit the low temperature of ground water for cooling purposes. The secondary heat exchanger can be any device or system that is operable to receive and exchange heat with a source of water, such as a dehumidifier.
[0018] In yet another embodiment, the system is provided with an auxiliary system that exploits cool winter temperatures for cooling purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Preferred embodiments of the present invention will now be described in greater detail and will be better understood when read in conjunction with the following drawings in which:
[0020] FIG. 1 is a schematical view of an irrigation reservoir cooling system according to an embodiment of the invention;
[0021] FIG. 2 is a schematical view of an irrigation reservoir cooling system according to another embodiment of the invention; and
[0022] FIG. 3 is a schematical view of an irrigation reservoir cooling system according to yet another embodiment of the invention.
DETAILED DESCRIPTION
[0023] With reference to FIG. 1 , the irrigation reservoir cooling system 100 of the present invention generally comprises a water conduit 200 , a cooling circuit 300 , a holding tank 400 , a primary heat exchanger 202 and a control unit 102 . The direction of fluid flow through the system is indicated by arrowheads.
[0024] In the embodiment of the invention shown in FIG. 1 , the irrigation reservoir cooling system is implemented for a building (not shown) with an external irrigation system (not shown). In general, water conduit 200 transports ground water, which is needed by the irrigation system, to holding tank 400 . Cooling circuit 300 operates to cool spaces within the building. Water conduit 200 and cooling circuit 300 are thermally coupled to heat exchanger 202 . Control unit 102 monitors and actuates the water conduit and the cooling circuit. Control unit 102 is programmed to fulfil irrigation and cooling needs and, at the same time, maximize the heat exchanged at primary heat exchanger 202 .
[0025] A more detailed description of major components of the irrigation reservoir cooling system follows. Water conduit 200 is a water line that is connected to a water source 204 . In the embodiment of the invention shown in FIG. 1 , water source 204 comprises a pressurized municipal water supply. In alternate embodiments, water source 204 can be an underground well or a deep pond. In these alternate embodiments, water conduit 200 is provided with a pump operable to move water through the water conduit.
[0026] The water conduit extends from water source 204 to holding tank 400 . Water conduit 200 is provided with a temperature sensor 206 and a first control valve 208 . Beyond first control valve 208 , water conduit 200 passes through primary heat exchanger 202
[0027] Generally, water flows though water conduit 200 as follows. Cool underground water flows into the water conduit from water source 204 . The water flows to first heat exchanger 202 , which exploits the low temperature of the water for cooling purposes. The water exits first heat exchanger 202 and flows to holding tank 400 , which stores the water for use by the irrigation system.
[0028] Water conduit 200 is also provided with an optionally usable bypass circuit 210 . Bypass circuit 210 provides an alternate route for water flowing through the water conduit. The alternate route bypasses first heat exchanger 202 . Bypass circuit 210 is provided with a second control valve 212 operable to control use of bypass circuit 210 .
[0029] Cooling circuit 300 is another major component of the irrigation reservoir cooling system. Cooling circuit 300 is a closed circuit provided with a first pump 302 , a first temperature sensor 304 , a second temperature sensor 306 , a chiller 308 , a chiller pump 310 , a third temperature sensor 312 , a second pump 314 , at least one fan coil circuit 316 and a fourth temperature sensor 318 . In front of first pump 302 , the cooling circuit passes through first heat exchanger 202 . The cooling circuit is filled with a fluid that can be water or any commercially available heat transfer fluid.
[0030] In the embodiment of the invention shown in FIG. 1 , cooling circuit 200 is provided with four optionally usable fan coil circuits 316 . Fan coil circuits 316 are connected in parallel to the cooling circuit downstream of second pump 314 . Each of the fan coil circuits is provided with two control valves 322 , 324 and a fan coil unit 320 . Control valves 322 , 324 are operable to control the flow of the fluid through their respective fan coil circuits 316 .
[0031] The fluid is pumped through cooling circuit 300 by pumps 302 , 310 and 314 . Generally, the fluid flows through cooling circuit 300 as follows. The fluid is pumped through first heat exchanger 202 , where the fluid is cooled by water flowing though water conduit 200 . The fluid is then pumped from the first heat exchanger to chiller 308 . Chiller 308 is operable to further reduce the temperature of the fluid. The fluid is pumped from the chiller to fan coil units 320 . Fan coil units 320 are located proximate to spaces in the building that can require cooling. Fan coil units 316 are operable to cool air and circulate said air through the spaces that can require cooling. Next, the fluid leaves the fan coil units and flows back to first heat exchanger 202 .
[0032] The cooling circuit is also provided with an optionally usable bypass circuit 326 that bypasses first pump 302 and first heat exchanger 202 .
[0033] Holding tank 400 comprises a water level sensor 402 , an overflow conduit 404 , and a low level float 406 . The capacity of the holding tank can vary depending on irrigation needs. In the embodiment of the invention shown in FIG. 1 , holding tank 400 has a capacity of 5000 gallons and water level sensor 402 is a commercially available ultrasonic level indicator. The holding tank supplies water to the irrigation system.
[0034] Water flows into holding tank 400 from water conduit 200 . In the embodiment of the invention shown in FIG. 1 , the holding tank is filled by water supplied by water conduit 200 . In alternate embodiments, water can also be supplied to holding tank by rainwater or thaw water. If the holding tank is ever filled to overflowing, the overflow water is directed by overflow conduit 404 to a drainage culvert 408 . In alternate embodiments, the holding tank comprises an emergency drain provided with an emergency pump operable to rapidly pump water from the holding tank into the culvert or a storm system.
[0035] Control unit 102 is a programmable unit with multiple signal inputs and output. In the embodiment of the invention shown in FIG. 1 , control unit 102 is a commercially available TAC Xenta™ 300 controller. Control unit 102 is in electronic communication with the above described sensors, pumps, control valves, chiller and irrigation system. The control unit is additionally in electronic communication with an external temperature sensor 104 , which measures outdoor temperature, and at least one thermostat (not shown) located within the building. In the embodiment of the invention shown in FIG. 1 , the control unit is connected to the sensors, pumps, control valves, heat exchanger, chiller and irrigation system by point to point wiring (not shown) easily accomplished by a competent electrician. The electronic connections can be either line voltage or 24V low voltage connections.
[0036] A description of the operation of the irrigation reservoir cooling system 100 according to the embodiment of the invention shown in FIG. 1 follows. A user of the irrigation reservoir cooling system inputs (sets) a desired temperature for a space within the building at a thermostat located within the space. When the temperature detected by the thermostat exceeds the desired temperature, the thermostat signals a need for cooling to control unit 102 . In response to the signal, control unit 102 executes steps to reduce the temperature of the space to satisfy the temperature setting of the thermostat.
[0037] First, the control unit actuates chiller pump 310 and second pump 314 , which operate to pump the fluid throughout cooling circuit 300 . Next, the control unit executes one of two set of steps based on the availability of cool ground water and storage capacity in holding tank 400 . Control unit 102 determines whether cool water is available based on the temperature of water from water supply 204 at first water temperature sensor 206 . Cool water is available when the temperature of water is below a predetermined temperature, 12° C. in the present embodiment, that represents a water temperature that is sufficiently cool to warrant using the water as a coolant. Control unit 102 determines whether storage capacity is available in holding tank based on input from water level sensor 402 .
[0038] If cool water is not available or storage capacity is not available, control unit 102 operates the cooling circuit as a stand alone cooling system. To this end, the control unit executes the following steps. First and second control valves 208 , 212 of water conduit 200 are closed. Control unit 102 actuates chiller 308 , which is operable to cool the fluid in cooling circuit 300 . The fluid is pumped to the chiller, where the fluid is cooled, and from the chiller to a fan coil unit 320 operable to cool the space where the thermostat is located. The fan coil unit uses the fluid to cool air that is then circulated though the space. The fluid leaving the fan coil unit is pumped back to chiller 308 , thus completing a loop of cooling circuit. If the temperature of fluid at third or fourth fluid temperature sensors 312 , 318 falls below the desired temperature, additional chilling of the fluid is no longer needed and control 102 unit deactuates the chiller.
[0039] Alternately, if cool water is available and storage capacity is available, the control unit operates system 100 to maximize heat exchange between water conduit 200 and cooling circuit 300 . To this end, the control unit executes the following steps. Control unit 102 opens first control valve 208 , closes second control valve 212 in the water conduit, and actuates first pump 302 in the cooling circuit. Opening first control valve 208 allows water from water supply 204 to flow through primary heat exchanger 202 . Actuating first pump 302 pumps the fluid of cooling circuit 300 through primary heat exchanger 202 . Within the primary heat exchanger, the fluid of the cooling circuit is cooled by the water of the water conduit. The water leaving primary heat exchanger 202 flows to holding tank 400 wherein the water is stored until the next irrigation operation. The fluid leaving primary heat exchanger 202 is pumped through the cooling circuit, to a fan coil unit 316 operable to cool the space where the thermostat is located. Fan coil unit 316 uses the fluid to cool air that is then circulated though the space. The fluid leaving fan coil unit 316 is pumped back to heat exchanger 202 , thus completing a loop of the cooling circuit.
[0040] If the temperature of the thermostat continues to rise and exceeds a predetermined threshold temperature, 1° C. above desired temperature in the present embodiment, and control valve 208 is fully open, the control unit actuates chiller 308 , which is operable to cool the fluid in cooling circuit 300 . Chiller 308 and heat exchanger 202 then work in concert to cool the fluid in the cooling circuit until either the temperature of the thermostat is lowered below the threshold temperature or the temperature of the fluid at third or fourth fluid temperature sensors 312 , 318 falls below the desired temperature. If either of these conditions is met, control unit 102 deactuates chiller 308 .
[0041] If the temperature of the fluid at fourth fluid temperature sensor 318 falls below the temperature of water from water supply 204 , heat exchanger 202 is no longer capable of cooling the fluid and the control unit closes first control valve 208 of the water conduit and deactuates first pump 302 of the cooling circuit.
[0042] For both sets of steps, described above, when the temperature of the thermostat reaches the desired temperature, cooling of the space is no longer needed and control unit 102 closes first control valve 208 and deactuates the cooling circuit by deactuating the pumps and the chiller.
[0043] Control unit 102 also actuates the irrigation system to perform periodic irrigation operations using water from holding tank 400 . When the above described cooling operations do not fill holding tank 400 with sufficient water to perform a scheduled irrigation operation, the control unit calculates the time needed to fill holding tank 400 based on input from water level sensor 402 and operates water conduit 200 to fill the holding tank in time for the irrigation operation. To this end, the control unit can open second control valve 212 in bypass circuit 210 so that ground water bypasses first heat exchanger 202 and flows directly to holding tank 400 . Control unit 102 will not actuate the irrigation system when low level float 406 communicates to the control unit that there is insufficient water in the holding tank.
[0044] FIG. 2 is a schematic diagram of another embodiment of the irrigation reservoir cooling system. In this embodiment, cooling circuit 300 comprises an optionally usable chiller circuit 328 provided with a second chiller 330 and a second chiller pump 332 . Second chiller 330 and second chiller pump 332 are connected to cooling circuit 300 in parallel with chiller 308 and chiller pump 310 . As with chiller 308 , second chiller 330 is operable to reduce the temperature of the fluid in cooling circuit 300 . Second chiller 330 and second chiller pump 332 are in electronic communication with control unit 102 . In operation, the second chiller and the second chiller pump are actuated when chiller 308 is not able to adequately cool the fluid in cooling circuit 300 . In the embodiment of the invention shown in FIG. 2 , if chiller 308 cannot provide sufficient cooling after 20 minutes of operation, control unit 102 actuates second chiller 330 and second chiller pump 332 to provide additional cooling. Control unit 102 deactuates the second chiller and the second chiller pump when additional cooling is no longer needed.
[0045] The roles of chiller 308 and second chiller 330 can be alternated on a weekly basis to equalize their run time. For example, every other week, second chiller 330 can be actuated first by control unit 102 , and chiller 308 actuated only to provide supplemental cooling.
[0046] Also with reference to the embodiment shown in FIG. 2 , water conduit 200 comprises a third control valve 214 and an optionally usable secondary branch 500 provided with a secondary heat exchanger 502 . As with primary heat exchanger 202 , secondary heat exchanger 502 is operable to exploit the low temperature of ground water from water source 204 for cooling purposes. Secondary heat exchanger 502 can be any device or system that is operable to receive and exchange heat with a source of water. In the embodiment of the invention shown in FIG. 2 , the secondary heat exchanger is a commercially available dehumidifier. Secondary branch 500 also comprises a first control valve 504 and a first water temperature sensor 506 . The secondary branch connects to the water conduit downstream of primary heat exchanger 202 and bypass circuit 210 . The secondary branch extends from water conduit 200 to holding tank 400 . Control unit 102 is in electronic communication with secondary heat exchanger 502 , first control valve 504 , and first water temperature sensor 506 .
[0047] In operation, control unit 102 functions as described above with respect to the embodiment of the invention shown in FIG. 1 and also determines if secondary heat exchanger 502 requires cooling for dehumidifying air that is being pumped through heat exchanger 502 . If the secondary heat exchanger requires cooling, the control unit opens first control valve 504 of branch conduit 500 and closes third control valve 214 of water conduit 200 . In this configuration, water that has passed through either primary heat exchanger 202 or bypass conduit 210 will flow to secondary heat exchanger 502 . The water flows through the secondary heat exchanger and then flows to holding tank 400 .
[0048] FIG. 3 is a schematic diagram of another embodiment of the irrigation reservoir cooling system. In this embodiment, the irrigation reservoir cooling system additionally comprises a snowmelt circuit 600 . Generally, snowmelt circuit 600 provides cooling to secondary branch 500 during winter months, when there is no demand for irrigation water Snowmelt circuit 600 passes through a tertiary heat exchanger 510 and is provided with a snowmelt pump 602 , a heat exchange panel 604 and a fluid temperature sensor 606 . Heat exchange panel 604 functions as a heat sink and is positioned outdoors, preferably in a location where unwanted snow accumulates, such as in a driveway. Snowmelt pump 602 circulates a fluid through the snowmelt circuit. The fluid can be any commercially available heat transfer fluid that remains in a liquid state when exposed to winter temperatures.
[0049] In the embodiment of the invention shown in FIG. 3 , secondary branch 500 passes through tertiary heat exchanger 510 downstream of secondary heat exchanger 502 and is provided with a first water temperature sensor 506 , a second water temperature sensor 508 , a freeze sensor 512 , a second control valve 514 and an optionally usable closed circuit branch 516 . Closed circuit branch 516 is provided with a closed circuit pump 518 and a one-way check valve 520 . Control unit 102 is in electronic communication with snowmelt pump 602 , fluid temperature sensor 606 , first and second water temperature sensors 506 , 508 , freeze sensor 512 , second control valve 514 , and closed circuit pump 518 .
[0050] Control unit 102 operates the snowmelt circuit 600 when there is no need for irrigation water and cool external temperatures can be used to fulfill cooling needs. When these conditions exist and secondary heat exchanger 502 signals a need for cooling, the control unit executes the following steps. Control valves 208 , 212 , 214 of the water conduit and control valves 504 , 514 of the branch conduit are closed. In this configuration, secondary branch 500 forms a closed water circuit that passes through secondary heat exchanger 502 and tertiary heat exchanger 510 . The control unit then actuates closed circuit pump 518 to pump water through the closed circuit as follows. Water is pumped from tertiary heat exchanger 510 , wherein heat is exchanged with snowmelt circuit 600 , through one-way check valve 520 of closed circuit branch 516 , to secondary heat exchange 502 , wherein the water cools the heat exchanger. The water is then pumped back to tertiary heat exchanger 510 , completing a loop of the closed circuit.
[0051] Control unit 102 also actuates snowmelt pump 602 , which pumps the fluid around the snowmelt circuit. The fluid is pumped from heat exchange panel 604 , wherein the fluid is cooled by the outdoors environment, to tertiary heat exchanger 510 , wherein the cooled fluid exchanges heat with secondary branch 500 . The fluid is then pumped back to the heat exchange panel, completing a circuit of the snowmelt circuit. In the embodiment of the invention shown in FIG. 3 , the snowmelt circuit is provided with an optionally usable waste heat circuit 608 , which further exploits the heatsink capacity of heat exchange panel 604 . The waste heat circuit directs fluid that is flowing from heat exchange panel 604 to a boiler or other waste heat source (not shown), and returns the fluid to snowmelt circuit 600 upstream of the heat exchange panel.
[0052] If water in secondary branch 500 at freeze sensor 512 is in danger of freezing, the irrigation reservoir cooling system reverts to using water source 204 to provide cool water to secondary heat exchanger 502 . To this end, control unit 102 opens control valve 212 of water conduit 200 , deactuates snowmelt pump 602 and closed circuit pump 518 , and opens first and second control valves 504 , 514 of secondary branch 500 .
[0053] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and sub combinations of the various features described hereinabove as well as variations and modifications which would occur to persons skilled in the art upon reading the specification and which are not in the prior art.
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A combined space-cooling and irrigation system and method of operation. The system is operated by an automated control unit specifically programmed to manage cooling and irrigation needs as follows. When irrigation water is needed, the system pumps cool water from a municipal water supply, a well, or a deep pond, through a heat exchanger on the way to a reservoir. The water pumped through the heat exchanger cools fluid in a separate closed circuit. The cooled fluid in the closed circuit is then used for cooling purposes, for example, to cool the air circulated through a house or building using a commercially available fan coil unit. The reservoir releases collected water for irrigation purposes at appropriate times.
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BACKGROUND OF THE INVENTION
This invention generally relates to form systems and methods for the molding of pre-cast structural components, and is specifically concerned with a system for the molding of pre-cast structural wall panels in a variety of different shapes, widths, architectural finishes for use in sound walls, mechanically stabilized earth walls, and anchored and gravity wall systems.
Forms for producing pre-cast concrete wall panels are well known in the prior art. Such forms are typically assembled from either wood or metal, and serve as molds for the manufacture of a particular kind of wall panel (i.e., a panel for use in a pile and lagging wall, acoustical wall, or post and panel wall) having a particular kind of architectural finish on its exposed side. In some kinds of walls, the architectural finish may be a simple, flat finish. However, in more decorative walls, the exposed side of the panel may have a brick-type finish, a vertical groove finish, a fractured fin finish, or even an imitation stone finish. In the case of acoustical walls, vertical flutes are commonly molded into the front face of the panels for sound-trapping purposes. The bottom surface of the mold is embossed with the architectural finish that is desired on the outer face of the resulting panel, while the side and ends of the form define the outer shape and thickness of the resulting panel. In use, after the forms have been assembled, structural panels are molded within them by first laying a pattern of reinforced steel within the mold space defined in their interior, and then by pouring liquid concrete into the form. After the concrete hardens, one or more of the sides or ends of the form is loosened from the hardened concrete, and the wall panel is withdrawn from the form. The process is repeated until the desired number of wall panels is manufactured.
While such prior art form systems are capable of satisfactorily producing the particular type and size of structural or architectural wall panel that they were designed for, the applicants have observed a number of areas where such form systems could stand improvement. For example, most prior art form systems are capable of producing wall panels of only a single size for a single type of wall system. However, due to the variations in the spacing between the piles or other members which support such wall panels in the finished wall, and further due to height variations in the finished wall, no single size of wall panel is capable of meeting all applications, even in the same type of wall. For example, in pile and lagging type walls, the distance between the support piles can vary between 6 and 10 feet. For sound walls, support pile distances can vary even further, i.e., between 10 and 20 feet. Of course, the ultimate height of the finished wall varies considerably, depending upon the purpose of the wall and the surrounding terrain. Thus there is a need for a form system capable of producing panels having widths of anywhere between 6 and 20 feet, and heights that similarly vary. However, the applicants are not aware of any prior art form system that is easily and accurately capable of producing panels over such a large variety of sizes. Still another shortcoming associated with prior art form systems is their relative inability to produce sound panels having different architectural finishes (i.e., vertical groove, fractured fin, or imitation brick, etc.) or even different thicknesses. Instead, known form systems utilize separate, dedicated forms for producing each different size of panel in each different type of architectural finish and thickness. Moreover, many prior art form system create structural wall panels in shapes which are relatively difficult to vertically or horizontally enlarge or contract should the need arise, such as hexagons, or cruciforms.
Clearly, what is needed is a form system and method that is capable of producing structural wall panels over a wide range of dimensions in order to accommodate widely varying spacing between the pilings or other support members which hold the finished wall in place, or connect it to earth reenforcing members. Moreover, such a form system and method should be easily and quickly adjustable to produce structural wall panels of radically different sizes with a minimum of time and labor. To this end, such a system and method should produce the wall panels in a shape which is readily enlarged or contracted with a minimum amount of mechanical adjustments. Moreover, such a system and method should be capable of producing not only different sizes of panels, but panels for different types of wall systems (i.e., soundwalls, MSE walls, anchored walls, etc. ) and of different designs as well. It would be desirable if the form system and method allowed the architectural finish that is embossed on the outer face of the wall panels to be changed in an easy and rapid manner. Finally, such a system and method should be capable of consistently producing panels of a selected height, width, and thickness consistently within relatively tight tolerances, so that the resulting panels fit together tightly in the finished wall. This last criteria is particularly important with respect to sound walls, where gaps between adjacent panels can provide undesirable acoustical leaks.
SUMMARY OF THE INVENTION
Generally speaking, the invention is both a form system and method that is far more versatile than prior art concrete forms, and which eliminates or at least ameliorates the aforementioned problems associated therewith. The form system of the invention generally comprises a base assembly that includes at least one rectangular base for supporting a quantity of concrete; at least one form liner supported by the base assembly for defining the bottom of a mold space and for imparting an architectural finish to panels molded by the form system; at least one pair of elongated side wall members for defining the sides of said mold space; means for adjustably securing the side wall members on opposing sides of the base assembly at a plurality of different heights; means for aligning the upper edges of each of the side wall members at a preselected height relative to the side edges of the form liner to define the thickness of the panels molded by the system; end wall members for defining the end walls of the mold space, and means for detachably mounting the end wall members transversely between the side wall members at any one of a plurality of positions in order to determine the length of the mold space defined by the resulting form.
The alignment means may include a flange which extends along the longitudinal axis of each of the side wall members for engaging one of the side edges of the form liner such that the height of the upper edge of each of the side wall members always stands a preselected distance from the form liner regardless of differences in the distances between the side edges of different form liners, and the base assembly which they overlie. The adjustable securing means that detachably connects the side wall members to the base assembly may include a plurality of vertically oriented slots alignable with welded nuts in the base assembly, such that a plurality of bolts may be used to secure the side wall members to the base assembly between maximum and minimum heights determined by the vertical length of the slots.
The means for detachably mounting the end wall members to the form may include opposing bracket members mounted along the top edge of each of the end wall members, and a plurality of bolts and welded nuts for securing bracket members onto the top portions of the side wall members at various locations along the longitudinal axis of the side wall members in order to define the length of any form manufactured from the resulting mold. A plurality of spaced apart welded nuts are provided at both ends of each of the side wall members so that each of the end wall members may be positioned at a variety of different distances at either end of the resulting form. The adjustability of both end wall members allows the form system to mold not only structural wall panels of a variety of different lengths, but wall panels having symmetrically-disposed architectural finishes on them.
Extension members may be provided for additionally extending the height of each of the side wall members so that the form system can mold structural wall panels that are thicker, if desired. These extension members may each include an angular piece of steel that is bolted into engagement with the upper inner edge of its respective side wall member. When such extension members are used, tubular spacers may be used in conjunction with the bracket and bolt means for connecting the end wall members over the side wall members so as to avoid interference between the brackets and the height extension members mounted on the upper inner edges of the side wall members.
Additionally, base width extenders may be provided for extending the width of the base assembly. In the preferred embodiment, each such base with extender may be bolted onto one of the sides of the base assembly through the same bolt holes that would normally serve to connect the side wall members to the base assembly. When so connected, the floor of the base width extender is aligned with the floor of the base assembly to create a single, continuous mold bottom. The outer side walls of each base width extender includes the same pattern of bolt holes as the sides of the base assembly to allow for the connection of the side walls of the form thereon.
In the method of the invention, a base assembly is first formed from either a single base, a pair of bases detachably connected into end, or a pair of bases attachably connected side-to-side, or four such bases connected end-to-end and side-to-side. Next, a form liner sufficiently large to cover substantially all of the upper area of the base assembly is laid over the upper surface of the base assembly. The flange means of two opposing side wall members is then overlaid into engagement with the side edges of the form liner so as to adjust the upper edges of each of the side wall members to the proper distance with respect to the inner surface of the form liner. Next, the bolts which secure the side wall members to the base assembly through the previously described vertically-oriented slots are tightened to secure each of the side wall members into its proper position. The end wall members are then detachably secured over opposite ends of the form liner by the bracket and bolt connecting system at selected positions along either end of the longitudinal axis of the respective side members to define a mold space capable of producing wall panels of a selected length.
The ability of the bases of the form system to interconnect into base assemblies of varying sizes, coupled with the height adjustability features of the side wall members, allows the system of the invention to produce structural wall panels of a variety of different dimensions and thicknesses in a rapid and economical manner.
BRIEF DESCRIPTION OF THE SEVERAL FIGURES
FIG. 1A is an exploded, perspective view of the form system of the invention illustrating both the principal components of the system and the manner in which they fit together, illustrating in particular how a single large base assembly may be formed by bolting together four separate bases;
FIG. 1B is an exploded, perspective view of the form system, illustrating how base width extenders may be mounted on the sides of the base assembly to extend the width of the base assembly;
FIG. 2 is a perspective, partially exploded view of the form system of the invention illustrating how the system appears when it is substantially assembled, and when only a single base forms the base assembly of the system;
FIG. 3 is a cross-sectional end view of the form system illustrated in FIG. 2 along the line 3--3;
FIG. 4A is an enlargement of the area enclosed in the dotted circle in FIG. 3 illustrating the details of the alignment mechanism of the system;
FIG. 4B is an alternative embodiment of the alignment mechanism of the form system;
FIG. 5 is a side view of one of the side wall members of the form system;
FIG. 6 is a partial elevational view of the side wall member illustrated in FIG. 5, illustrating the bolt holes used in the length adjustable mounting system of the invention;
FIG. 7A is a side view of one of the end wall members of the form system;
FIG. 7B is a cross-sectional view of the end wall member illustrated in FIG. 7A, along the lines 7B--7B;
FIG. 8A is a partial cross-sectional end view of the system of the invention, illustrating in particular how the length adjustable mounting system detachably connects the end wall members to the side wall members, and
FIG. 8B is a cross-sectional side view of the end wall member and mounting system illustrating in FIG. 8A, along the line 8B--8B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to FIGS. 1A,B and 2, wherein like numbers designate like components throughout all the several figures, the form system 1 of the invention includes a base assembly 3 which may be formed from either a single base 5a (as is illustrated in FIG. 2), or any combination of bases 5a-d bolted together end to end, side to side, or both ways as FIG. 1A indicates. The identical rectangular shape of each of the individual bases 5a-d, allows the operator of the system 1 to conveniently double either the length or width, or both the length and the width of a single base. The system 1 further includes a plurality of sheet-like form liners 7 (of which only one is shown) which are dimensioned so that they cover most or substantially all of the top surface of the base assembly 3. Also included are a plurality of left and right side wall members 9a,b. Each side wall member is aligned at a proper height with respect to the form liner 7 by means of an alignment mechanism 11 after the liner 7 has been disposed on top of the base assembly 3. Each side wall member is further detachably secured into this aligned position by means of a height adjustable mounting system 13. As will be described in more detail hereinafter, the height adjustable mounting system 13 generally comprises a plurality of bolts which extend through vertically-oriented slots in each of the side wall members 9a,b and which threadedly engage the bases 5a-d through bolt holes located along the sides of each base. As is shown in FIG. 1B, the system 1 further includes base width extenders 10a,b for extending the width of a single base 5a. Finally, the system 1 includes a pair of end wall members 15a,b which are detachably connected between the side wall members 9a,b and over the upper surface of the form liner 7 by means of a length adjustable mounting system 17. As is described in more detail hereinafter, the mounting system 17 allows each of the wall members 15a,b to be bolted at a desired position along the longitudinal axis of the base assembly 3, which in turn allows the system operator to choose the length of the panels molded in the forms.
With reference now to FIGS. 1A and 3, each of the bases 5a-d includes a box-like support table 20 that is formed from an upper wall 22, a lower wall 24, side walls 26a,b and end walls 28a,b. In the preferred embodiment, each of the various walls of the support table 20 is formed from ten gauge sheet steel, both for durability as well as for the ability to accurately mold a structural wall panel. Three reinforcing rails 30 are welded to the underside of the upper wall 22 and connected to the end walls 28a,b in order to rigidify the upper wall 22 of the base 5a. Such rigidification prevents the upper wall 22 from sagging from the weight of the concrete poured into the form during the panel molding operation. At the bottom of the support table 20 are four angular leg flanges 32a-d. Four feet 34 may be connected to these leg flanges, if desired. Each of the leg flanges 32a-d includes an end bolt hole 35 and a side bolt hole 37. The end bolt holes 35 receives nut and bolts (not shown) which allow the bases 5a-d to be connected end to end, while the side bolt holes 37 allow the same bases to be connected side to side if desired. Finally, the side walls 26a,b of each of the support tables 20 of the bases 5a-d includes a plurality of bolt holes 38 uniformly spaced along its longitudinal axis, as may best be seen in FIG. 1. Welded nuts 39 are secured around each of the bolt holes 38 in the interior of the support table 20, as may best be seen in FIG. 3. The welded nuts 39 threadedly receive bolts which form part of the height adjustable mounting system 13 that secures the side wall members 9a,b to the base assembly 3.
With reference now to FIG. 1B, the width of the base assembly 3 may be extended by the use of base width extenders 10a,b if relatively small extensions of the width are desired. The structure of each base width extender 10a,b is substantially similar to that described with respect to the bases 5a-d, with each such extender having inner and outer walls 40a,b with a pattern of bolt holes 32 and welded nuts (not shown) that are registrable with the bolt holes 32 of the bases 5a-d and the bolt slots 52 of the side wall members 9a,b. The right angle flanges at the bottom of each of the inner walls 40a serves to rigidify the extender. The only major differences between the base width extenders 10a,b and the bases 5a-d are that the extenders 10a,b include no lower wall 24 or reenforcing rails 30. The lack of these components allows the system operator to freely insert bolts through the bolt holes 41 on the inner walls 40a of each extender 10a,b, and to ring these bolts into the welded nuts 39 in the interior of the support table 20 of the base 5a-d.
With reference now to FIGS. 1A,B, 2 and 3, each of the form liners 7 is dimensioned to cover most or substantially all of the upper surface of the base assembly 3 that it rests upon. Such substantial coveting is important, particularly when the base assembly 3 is formed from two or more bases 5a-d, as the form liner 7 defines a single, unitary mold bottom for the resulting form that prevents any unsightly seams or blemishes from being created in the resulting wall panel as a result of concrete running into the small gaps which must necessarily exist between adjacent bases 5a-d. The contours 42 of the particular form liner 7 used in the system defines the architectural finish of any structural wall panel molded thereover. While the liner 7 illustrated in FIGS. 1-3 is a vertical-groove type finish 43, the liner 7 can impart any desired type of finish on the resulting wall panel, and the system 1 contemplates the use of not only form liners embossed with different architectural finishes, but liners having a variety of different lengths and widths such that wall panels of widely varying sizes and finishes may be produced by the same system 1. While the form liners 7 may be formed from rubber or plastic, sheet metal is preferred. In the preferred embodiment, each of the form liners 7 includes a pair of side flanges 44a,b. As will be discussed hereinafter, these side flanges 44a,b advantageously cooperate with alignment flanges on the inner walls of the side members 9a,b to form the alignment mechanism 11 which properly and automatically adjusts the height of the side wall members 9a,b over the form liners 7 when the form system 1 is assembled.
With reference now to FIGS. 5, 6 and 8A, the leftmost side wall member 9a includes an inner wall 50 which abuts against the side wall 26a of the base and which defines one of the mold surfaces of the form system 1. The inner wall 50 is preferably formed from sheet steel and includes a flat lower portion 51 which includes a plurality of uniformly spaced apart bolt slots 52 (which may best be seen in FIG. 1). The inner wall 50 further includes a recessed upper portion 53 for defining a fib-like protrusion along the side of any wall panel molded thereby. The inner wall 50 is generally rectangular in shape and is stiffened around its perimeter by a reinforcing frame 54. The frame 54 includes end plates 55, and upper and lower frame members 56 and 57 which are welded together at their joints and to the wall 50. The inner side wall 50 is further stiffened by a plurality of reinforcing gussets 58. Such reinforcing advantageously prevents the inner wall 50 from bowing or otherwise distorting in response to the load applied to it by the liquid concrete when the form system i is used to manufacture wall panels. As may best be seen in FIG. 5, a plurality of rectangular bolt lock plates 60 are welded onto the inner edges of the upper and lower frame members 56,57. Each of the bolt lock plates 60 includes a vertically oriented slot 62 in registry with one of the bolt slots 52 of the inner wall 50. The bolt lock plate 60 not only serves to further strengthen the side wall member 9a, but also provides a resilient, reactive surface which acts as a lock washer when a bolt is extended through the two slots 52 and 62 and threaded into engagement when one of the welded nuts 39 secured to the interior of the side wall 26a. As is most easily seen in FIG. 6, the upper frame member 56 of the side wall member 9a includes two sets of bolt holes 64a,b on either of its ends. In the preferred embodiment, each of the bolt holes are spaced apart approximately three inches. Welded between each one of the bolt holes 64a,b is a nut 66, best seen in FIG. 5. As will be better appreciated hereinafter, the two sets of bolt holes 64a,b and welded nut 66 form part of the previously mentioned length adjustable mounting system 17 for the end wall members 15a,b. Finally, the upper frame member 56 of the side wall member 9a includes a vibrator coupling 67 which may be formed from a pair of bolts as shown. The vibrator connector 67 allows the side member 9a to be conveniently connected to a vibrator of the type which helps to remove unwanted bubbles and air pockets from liquid concrete after it has been poured into the mold defined by an assembled form system 1.
With reference now to FIGS. 3 and 8A, the structure of the right hand side wall member 9b is similar, but not identical to that of the left hand member 9a. While the side wall member 9b includes an inner wall 50 which includes vertically oriented, bolt receiving slots spaced apart in the same fashion as that described with respect side wall member 9a, and while the flat lower portion 70 of the inner wall 50 is likewise circumscribed by a reinforcing frame 54 that includes reinforcing gussets 58 and bolt lock plates 60, the upper portion 70 of this wall is not integrally formed with the lower portion 70, but instead is detachable therefrom. Specifically, the upper wall portion 72 includes a lower flange 74 that is attached onto the upper frame member 56 by nut and bolt connectors 76. Such detachability is necessitated by the fact that the upper wall portion 72 protrudes into any wall panel molded within the form system, and hence must be removed if the resulting panel is to be lifted out of the form without mechanical interference. The upper wall portion 72 terminates in a top flange 78 which is aligned with the upper frame member 56 of the side wall member 9a when the form system 1 is assembled. Like upper frame member 56, top flange 78 likewise includes two sets of bolt holes 64a,b at either of its ends, best seen in FIGS. 1 and 2. Nuts 66 are welded beneath each of the bolt holes in the bolt hole set 64a,b for a purpose which will become evident shortly.
With reference now to FIG. 4A, the alignment mechanism 11 of the form system 1 includes a tapered flange 84 which is welded along the longitudinal axis of the inner wall 50 of both of the side wall members 9a,b by weld bead 85. The flange 84 rests on top of one of the side flanges 44a of the form liner 7 disposed over the base assembly 3 when the form is assembled. Weld bead 85 is shaped in conformity with the taper of the flange 84 as shown. Such a tapered shape facilitates the removal of any wall panel molded within the form system 1. When the lower surface of the flange 84 is engaged against the upper edge of the side flange 44a as shown in FIG. 4A prior to the securing of the side wall members 9a,b to the base assembly 3, the upper edge of the side wall 50 of the side wall members 9a,b is properly spaced with respect to the upper surface of the form liner 7. When the side wall panels are secured in this position, any wall panel manufactured by the form system 1 achieves a proper and precise thickness. FIG. 4B shows an alternative embodiment of the alignment mechanism 11 of the invention. In this embodiment, the flange 84 is replaced by a rectangular recess 86 defined by a pair of right angular bends 87a,b in the inner wall 50. The relatively smoother mold contours provided by this particular embodiment of the alignment mechanism 11 allows any panel molded within the form system 1 to be removed with somewhat less mechanical interference than with the alignment mechanism 11 of FIG. 4A.
With reference again to FIG. 5, the height adjustable mounting system 13 is formed from a plurality of bolts 90 which extend through the vertically oriented slots 52 and 62 present in the inner walls 50 and bolt lock plates 60 of each of the side wall members 9a,b. Through these slots, the threaded ends of the bolts 90 extend through the bolt holes 38 present on either side of the bases 5a-d forming the base assembly 3, and from thence into the nuts 39 welded around the inner periphery of these holes 38 in the interior of the base. In operation, when the nuts 90 are slightly loosened, the side wall members 9a,b can be slid upwardly or downwardly (or even tilted slightly away from their respective base) to allow an operator to slide a desired form liner 7 over the upper surface of the base 5a and then to vertically adjust the position of the side wall members 9a,b such that the inner flange 84 (or rectangular recess 86) of the alignment mechanism 11 overlies one of the side flanges 44a,b of the form liner 7 in the position illustrated in FIG. 4A. Once such alignment is achieved, the bolts 90 can be tightened until the side members are firmly and rigidly secured to the base assembly 3.
With reference now to FIGS. 7A and 7B, each of the end wall members 15a,b includes an inner wall 96 formed from thick gauge sheet steel which forms the part of the mold surface of the form system 1. The inner wall 96 may be provided with a protruding rib 98 for creating a recess in the wall panel molded therefrom or it may be provided with a longitudinal recess if the formation of a rib on the end of the wall panel is desired. Similar to the previously described side wall members 9a,b, the inner wall 96 of each of the end wall members 15a,b is circumscribed by a support frame 100 that comprises an upper frame member 102, a lower frame member 104, and side walls 106a,b. One side of each of the end wall members includes a recess 108, while the other includes a protrusion 110, the recess and protrusion being complementary in shape to the inner wall 50 of the particular side wall member 9a,b that it abuts against when assembled. Three or more sheet metal gussets 112 are welded within the support frame 100 for added strength. Finally, a tapered lip 113 is provided along the bottom edge of the inner wall 96 to facilitate the removal of any wall panel manufactured by the form system 1.
With reference now to FIGS. 8A and 8B, the length adjustable mounting system 17 which adjustably and detachably secures each of the end wall members 15a,b to the form system 1 includes a pair of side brackets 116a,b formed from steel angles as shown. The bottom flange 117 of each of the side brackets 116a,b is welded to a plate spacer 118, which in turn is welded onto the top surface of the upper frame member 102. A bolt hole 120 is provided at the distal end of the bottom flange 117 of each of the side brackets 116a,b. Additionally, a tubular spacer 122 (which may be manufactured from a short section of steel pipe) is welded around the bolt hole 120 of each of the brackets 116a,b. In operation, a bolt 124 is slid through the bolt hole 120 of each of the side brackets 116a,b when that hole is aligned with a desired one of the bolt holes 64a,b present on either end of the side wall members 9a,b. The bolt 124 is then screwed into the welded nut 66 circumscribing the selected one of the bolt holes 64a,b.
The form system 1 also includes a pair of wall extenders 128 which may optionally be used to extend the height of the mold surfaces defined by the inner walls 50 of the side wall members 9a,b. Each of the wall extenders 128 includes a vertical flange 129 that is aligned co-planar with the inner wall 50 when it is secured into position by means of a nut and bolt (not shown). Each of the wall extenders 128 further includes a horizontal flange 131 having a bolt hole 133 that is registrable with an inner bolt hole 134 that is also present on the upper surfaces of each of the side wall members 9a,b.
In the first step of the method of the invention, the operator of the form system determines the length and width of the particular kind of structural wall panel that he desires. The selected width and length will, of course, determine how many bases 9a-d will be interconnected to form the base assembly 3, or how many base width extenders 10a,b will be connected to a single base 5a-d to form the base assembly 3. Once these decisions have been made and the appropriate number of bases and/or base width extenders 10a,b have been bolted together by aligning the appropriate bolt holes, the system operator determines what type of architectural finish the wall panels produced by the system 1 should have. Once the particular type of finish has been selected, a form liner 7 having the selected finish embossed in its interior is next placed over the upper surface of the base assembly 3. In the next step of the method, the side wall members 9a,b are properly vertically aligned with respect to the bottom surface of the form liner 7 by placing either the previously described flange 84 or recess 86 of the alignment mechanism 11 over the particular side flange 44a,b of the form liner 7 that it faces. Such vertical alignment may be easily done with the bolts 90 of the height adjustable mounting system 13 in a loosened state, as has been previously described. Once the desired vertical alignment has been achieved, the bolts 90 of the system 13 are then tightened. In the next step of the method, the system operator determines what particular thickness the resulting wall panels should have. Specifically, if the system operator decides that the resulting wall panels should be thicker than the distance between the upper edges of the side wall members 9a,b in the upper surface of the form liner 7, the previously described wall extenders 128 are secured on the upper edges of the side wall members 9a,b in the manner previously described. The system operator then determines what length the resulting wall panels should have. He then proceeds to install the end wall members 15a,b between the side wall members 9a,b in such a way that the distance between the end wall members 15a,b corresponds to the selected length of the resulting wall panel. This step is, of course, implemented by bolting the ends of the side brackets 116a,b of each of the end wall members 15a,b to selected ones of the previously described bolt holes 64a,b present on the upper surfaces of each of the side wall members 9a,b. In preforming this step of the method, it is important to note that the provision of two separate sets of bolt holes 64a,b at both ends of each of the side wall members 9a,b allows the system operator to achieve the selected length of the resulting panel with more than one combination of bolt holes. This capability advantageously allows the system operator to achieve not only a desired panel length, but a desired symmetry with respect to the architectural finish embossed on the upper surface of the form liner 7.
In the next step of the method, a pattern or gridwork of reinforcing steel is laid into the form system 1, and concrete is then poured into the mold surface defined by the upper surface of the form liner, and the inner surfaces of the side wall members 9a,b and end wall members 15a,b until the concrete reaches the upper edge of the side wall members 9a,b. After the concrete hardens, the end wall members 15a,b are removed by removing the bolts 124 of the length adjustable mounting system 17, and the upper wall portion 72 of the side wall member 9b is removed. The newly manufactured wall panel is then removed from the form system 1 and the process is repeated until the desired number of wall panels of the selected length, width and thickness and architectural finish is fabricated.
While certain modifications, rearrangements and alternate embodiments of both the system and the method of the invention will become evident to persons of ordinary skill in the art, all such modifications, variations and embodiments are intended to be encompassed within the scope of this patent, which is limited only by the claims appended hereto.
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A form system and method is provided that is capable of molding pre-cast, structural wall panels of different lengths, widths, thicknesses and architectural finishes for a variety of different types of wall systems. The form system comprises a base assembly formed from at least one rectangular base, a plurality of form liners supportable by the base assembly for defining the bottom of a mold space and for imparting different architectural finishes to panels molded thereby, a pair of elongated side wall members for defining the sides of the mold space, a plurality of vertically-oriented slots and bolts in each of the elongated side wall members for adjustably mounting these members at different heights with respect to the base assembly, an alignment flange on the inside surfaces of each of the side wall members engagable against the side edges of the selected form liner for aligning each of the side wall members to a proper height with respect to the form liner, and end wall members detachably connectable between the two side wall members for defining the end walls of the mold space. The system of the invention is capable of molding panels for mechanical stabilized earth walls, acoustical walls, pile and lagging walls, or post and panel walls quickly, reliably, and dimensionally consistently with only a relatively few easily adjustable components.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/993,598, filed on Sep. 13, 2007, and herein incorporated by reference in its entirety.
FIELD OF INVENTION
[0002] The present invention relates to locks for sealing containers used in transporting cargo or goods generally, or people, via truck/trailer, train, ship, manual means, or otherwise. The invention utilizes any pin-style seal lock, but one which incorporates an attached module that includes RFID which is active, passive, semi-active, or semi-passive; as well as incorporating GPS (Global Positioning System), Cellular Technology which can be, for example but not limited to, GSM (Global System for Mobile Communications), CDMA (Code Division Multiple Access) or other technologies, and GPRS (General Packet Radio Service).
BACKGROUND OF THE INVENTION
[0003] Cargo locks (such as pin-style locks) for containers and other large transportation vessels are typically used in shipping or transport operations. These known locks are mechanical locks which do not have any electronics and are employed by shipping companies to seal the container or vessel against unauthorized intrusion. Most of these locks are utilized to provide a means for the owner of the contents to ascertain if the cargo housing carrying the contents has been breached or tampered with.
[0004] That is, known pin-style (or, ‘bolt-style’) locks are capable of indicating whether they have been previously opened, as such locks typically must be permanently marred or otherwise destroyed in order to separate the various portions of the lock. As such, it is the physical state of the lock which indicates whether it has been opened, and therefore, whether the goods within the container or vessel may have been tampered with.
[0005] RFID devices have been known to be integrated with pin-style locks, and provide a means for electronically communicating with any such seal/lock, during those times when the seal is interrogated by a reader having the appropriate or matching communication protocol.
[0006] Also known are GPS systems which communicate with satellites and are typically used to determine the exact location of the GPS receiver.
[0007] For its part, GSM is the dominant technology used around the globe, currently available in more than 100 countries, for mobile/cellular communication. It is the standard for communication for most of Asia and Europe. GSM allows for simultaneous calls on the same radio frequency and uses “narrowband” TDMA, the technology that enables digital transmissions between a mobile phone and a base station. With TDMA the frequency band is divided into multiple channels which are then stacked together into a single stream, hence the term narrowband. This technology allows several callers to share the same channel at the same time.
[0008] GPRS is a Mobile Data Service available to users of (GSM). GPRS can be used for services such as Wireless Application Protocol (WAP) access, Short Message Service (SMS), Multimedia Messaging Service (MMS), and for Internet communication services such as email and World Wide Web.
[0009] With the forgoing problems and concerns in mind, it is the general object of the present invention to provide tracking module with global positioning system for cargo and goods which is capable of interfacing with a dedicated software system so as to provide for accurate tracking, status and security information, as desired.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide a single universal tracking module.
[0011] It is another object of the present invention to provide a single universal tracking module that is capable of communicating with a plurality of known communication protocols.
[0012] It is another object of the present invention to provide a single universal tracking module that is capable of communicating with a plurality of known communication protocols and which attaches to any pin-style cargo security lock.
[0013] It is another object of the present invention to provide a single universal tracking module that is integrated with a dedicated software system.
[0014] It is another object of the present invention to provide a single universal tracking module that is integrated with a dedicated software system.
[0015] It is another object of the present invention to provide a single universal tracking module that is integrated with a dedicated software system to provide for accurate tracking, status and security information, as desired.
[0016] It is another object of the present invention to provide a single universal tracking module that is integrated with a dedicated software system for interactive mapping and information retrieval.
[0017] These and other objectives of the present invention, and their preferred embodiments, shall become clear by consideration of the specification, claims and drawings taken as a whole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic illustration of a universal tracking module, in accordance with one embodiment of the present invention.
[0019] FIG. 2 graphically depicts the universal tracking module as part of an overall software system used to provide for accurate tracking, status, mapping and security information.
[0020] FIG. 3 illustrates the universal tracking module of FIG. 1 , as integrated with a pin-style locking device.
DETAILED DESCRIPTION OF THE INVENTION
[0021] As shown in FIG. 1 , a single universal tracking module 10 includes a plurality of integrated components, which are capable of interfacing with a plurality of known communication protocols. As will be discussed in more detail later, the universal tracking module 10 may itself be integrated with any known pin-style cargo security lock.
[0022] The preferred components of the universal tracking module 10 include a RFID device 12 , which may be either active, passive, semi-active, or semi-passive, as is known in the art. Also included are a GPS device and antenna array 14 , and additional cellular technology, such as a GSM device 16 and a GPRS device and antenna array 18 . While FIG. 1 illustrates that the preferred cellular technology is the GSM 16 and the GPRS 18 , due to widespread use and coverage, it will be readily appreciated that other technologies and related protocols could be employed without departing from the broader aspects of the present invention.
[0023] It will further be appreciated that GPRS is a known mobile data service available for users of GSM. GPRS can be utilized with services such as Wireless Application Protocol (WAP) access, Short Message Service (SMS), Multimedia Messaging Service (MMS), and Internet communication services such as email and World Wide Web access.
[0024] Referring again to FIG. 1 , the universal tracking module 10 further includes power conditioning circuits 20 which themselves are in internal communication with a battery assembly 22 as well as a battery charging port 24 , or the like. An input/output (I/O) connection means 26 is also integrated with the universal tracking module 10 , to provide for audio, SIM, GPIO, serial, or other known communications and information exchanges.
[0025] Turning now to FIG. 2 , it is graphically depicted that the universal tracking module 10 is part of an overall software system used to provide for accurate tracking, status, mapping and security information as related to the tracking module 10 (and the container or vessel to which it is attached). As shown in FIG. 2 , the software system is shown schematically as being part of a dedicated computer terminal 30 . It will be readily appreciated that the software system of the present invention can be stored locally in machine readable format at the location of the computer terminal, or terminals, 30 , or can be remotely hosted, without departing from the broader aspects of the present invention.
[0026] As illustrated graphically in FIG. 2 , the software system/terminal 30 is linked with a reader/ writer 32 for the selective scanning and interrogation of the RFID device 12 . The software system/terminal 30 is thereby also linked to the other interrelated elements ( 14 / 16 / 18 / 20 / 22 / 24 / 26 ) contained within the tracking module 10 , so as to provide data communication on shipping and manifest information 34 relating to the container, truck, train, ship, etc that is equipped with the RFID device 12 .
[0027] As also shown in FIG. 2 , the software system/terminal 30 is additionally capable of acquiring GPS and tracking data 36 (via GPS satellites 38 , or the like) for the interrogated RFID device 12 , and may use one or more of the Internet, GSM/GPRS or WAN protocols in doing so. Such information can also be transmitted to/from the RFID device 12 via SMS protocols. In this manner, accurate position/location information can be obtained with respect to the tracking module 10 .
[0028] In addition to storing container information in the RFID device 12 , including information on the type of item(s) stored within a container so equipped, one object of the present invention is to integrate the universal tracking module 12 with known pin-style locks, for greater functionality. FIG. 3 illustrates the universal tracking module 10 as integrated with a pin-style locking device 40 . By so integrating the two components, it is possible for the RFID device 12 to store status and other ‘condition’ information relating to the pin-style-lock 40 itself, as well as storing information of the contents of a specific container to which it may be attached.
[0029] In operation, the scanning of the RFID device 12 automatically verifies that the pin-style lock 40 is valid and provides alerts if the lock has been tampered with. It will be readily appreciated that these alerts may be audible, visual, or a combination of both, as well as being transmitted by the software system and terminal 30 via Internet, GSM/GPRS, WAN or other known communication protocols (as best shown in FIG. 2 ). If the interrogation of the RFID device 12 indicates that the pin-style lock 40 has not be opened or otherwise tampered with, the shipping and container data is displayed from the centralized data repository, also in communication with the software system and terminal 30 .
[0030] Further, if the need exists, data from US Customs AMS for Overseas Ocean and Air Shipments and associated systems for trucking and train can also be accessed. As discussed previously, the scan is linked to the central data repository via Internet, GSM/GPRS, WAN or other known communication protocols.
[0031] It is another object of the present invention is to provide a universal tracking module 10 , and related system, that is capable of providing authorized users access to the exact location of a cargo shipment using the onboard GPS. The onboard GPS receives its location, which gets transmitted via GSM and GPRS. This would typically be transmitted via the Short Message Service (SMS), but can be transmitted via any available technology. Once transmitted, an individual phone, PDA, computer or web-based service, or similarly capable devices, can display the location of the shipment. The transmissions of locations are saved, in or in connection with the software system and terminal 30 , to allow for the automated plotting of the route a shipment/container has taken.
[0032] The GPS device and antenna array 14 will therefore allow authorized users to query the location of the RFID device 12 on demand, to set the frequency of reporting, to review historical information, to view health/condition of the module 10 , and any of the GPS data that has been recorded (such as tracking/ position information).
[0033] The tracking module 10 is also configured to allow for the addition of various sensors to be connected, via the previously discussed I/O port 26 . Data from these sensors can be transmitted via the GSM/GPRS network in the same manner as the GPS data.
[0034] A Web based interface is provided for the RFID device 12 , and related shipping/container data. In addition, the software system/terminal 30 can store shipment and manifest information to be available for review, also upon user authentication. A Web based interface is also available for the GPS and shipping data.
[0035] It is yet another aspect of the present invention that the software system/ terminal 30 can utilize all receive or transmitted information so as to generate a transit map of any shipping/container which is equipped with the RFID device 10 . It will be readily appreciated that the software system/ terminal 30 may utilize a standard mapping program to display a historical overlay containing the tracking information of the given shipment and associated RFID device 12 . It will also be readily appreciated that the computer software and terminal assembly 30 displays the historical transit map on a suitable visual display, for subsequent interaction by an authorized operator.
[0036] It is still yet another important aspect of the present invention that an authorized operator may determine historical shipment/ container information from the tracking module 10 by enabling an operator to simply ‘click’ on any data point generated by the mapping program. In doing so, an operator may ‘click’ on any data point on the generated transit map, as displayed, and thereby receive shipment/container information that was true as of the time the tracking module 10 was present at the location identified by the generated transit map.
[0037] While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all embodiments falling within the scope of the appended claims.
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An integrated radio frequency identification system includes a locking assembly affixed to a shipping container and a tracking module having a RFID device in electrical communication with the locking assembly. The tracking module includes integrated GPS components enabling communication with GPS satellites. A machine readable computer software and terminal assembly is provided and is capable of communication with the RFID device via one of a plurality of communication protocols. The computer software and terminal assembly is capable of generating a transit map of a location and status of the tracking module over a predetermined time period, thus graphically depicting a historical transit path of the tracking module.
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This invention was made with Government support under Grant No. AI 27179 awarded by the National Institutes of Health. The Government has certain rights in the invention.
This is a division of application Ser. No. 07/963,620, filed Oct. 20, 1992, which is a continuation of application Ser. No. 07/596,183, filed Oct. 12, 1990, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to biologically active fatty acid analog substrates of myristoylating enzymes and, more particularly, to azido-substituted fatty acid analogs which are useful in the fatty acid acylation of peptides and proteins.
Fatty acid acylation of specific eukaryotic proteins is a well established process which can conveniently be divided into two categories. On the one hand, palmitate (C 16 ) is linked to membrane proteins via ester or thioester linkage post-translationally.
On the other hand, it is known that myristate (C 14 ) becomes covalently bound to soluble and membrane proteins via amide linkage early in the protein biosynthetic pathway. In the N-myristoylated proteins, amino-terminal glycine residues are known to be the site of acylation.
A variety of viral and cellular proteins have been shown to be thus modified by the covalent attachment of myristate linked through an amide bound to glycine at their amino termini. An example of a most thoroughly studied myristoylated protein is the transforming protein of Rous sarcoma virus, p60 v-src .
The myristoylation reaction can be represented as follows: ##STR1##
Further background information on the above protein fatty acid acylation can be had by reference to the following series of articles by scientists associated with the Washington University School of Medicine:
Towler and Glaser, Biochemistry 25, 878-84 (1986);
Towler and Glaser, Proc. Natl. Acad. Sci. USA 83, 2812-2816 (1986);
Towler et al., Proc. Natl. Acad. Sci. USA 84, 2708-2712 (1987);
Towler et al., J. Biol. Chem. 262, 1030-1036 (1987);
Towler et al., Ann. Rev. Biochem. 57, 69-99 (1988);
Heuckeroth et al., Proc. Natl. Acad. Sci. USA 85, 8795-8799 (1988); and
Heuckeroth and Gordon, Proc. Natl. Acad. Sci. USA 86, 5262-5266 (1989).
Unique synthetic peptides having relatively short amino acid sequences which are useful as substrates of myristoylating enzymes are described in U.S. Pat. Nos. 4,740,588 and 4,778,878. Examples of such peptides are
Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg and Gly-Asn-Ala-Ala-Ser-Tyr-Arg-Arg.
Certain other unique synthetic peptides are inhibitors of myristoylating enzymes as described in U. S. Pat. Nos. 4,709,012 and 4,778,877.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention, biologically active fatty acid analog substrates for myristoylating enzymes are provided. These compounds are azido- or azido-like-substituted fatty acid analogs which can also contain oxygen and/or sulfur heteroatoms in the fatty acid backbone. They are useful in the fatty acid acylation of peptides and proteins. The preferred fatty acid analogs can be represented by the following two groups of chemical structures:
Z--(CH.sub.2).sub.x COOR (I)
wherein
Z=azido, tetrazolyl or triazolyl,
R=H or C 1-8 alkyl, and
x=8-12.
Compounds of structure I (II)
in which a methylene group from carbon position 3 to within 2 carbons of Z is replaced by oxygen or sulfur. The carboxyl carbon atom is defined in this structure as number 1 based on conventional nomenclature.
These novel substrate compounds are useful for studying the regulation of enzyme action in fatty acid acylation and the role of N-myristoylation in protein function. They can serve as synthetic substrates for the N-myristoylating enzymes in sources such as yeasts, fungi, wheat germ lysates and mammalian cells. These novel compounds differ in hydrophobicity from myristic acid while maintaining approximately the same chain length. Thus, when incorporated into myristoylproteins, they should alter the acylprotein's subsequent interactions with membranes or with other proteins. They also have potential use as antiviral, antifungal and antineoplastic agents.
Illustrative examples of the biologically active azido-substituted fatty acid analogs of this invention are:
______________________________________Name Compound No.______________________________________12-Azidododecanoic acid (1)11-Azidoundecanoic acid (2)9-Azidononanoic acid (3)13-Azidotridecanoic acid (7)5-(1-Azido-hexane-6-thia)- (13)pentanoic acid2-(1-Azido-nonane-9-thia)- (19)acetic acid4-(1-Azido-octane-6-thia)- (23)propionic acid9-(1-Azido-ethane-2-oxa)- (40)nonanoic acid8-(1-Azido-propane-3-oxa)- (41)octanoic acid5-(1-Azido-hexane-6-oxa)- (42)pentanoic acid2-(1-Azido-nonane-9-oxa)- (43)acetic acid12-(Tetrazolyl)dodecanoic acid (46)12-[1,2,4]-Triazolyl)dodecanoic (48)acid12-(N-2-[1,2,3]-Triazolyl)- (50)dodecanoic acid______________________________________
DETAILED DESCRIPTION OF THE INVENTION
The azido-substituted fatty acid analogs of this invention can be prepared by various reaction schemes. For example, in one scheme an ω-iodocarboxylic acid having the desired fatty acid chain length can be reacted with azide ion, e.g. potassium or sodium azide, and 18-Crown-6 in organic solvent medium, e.g., DMF, at normal room temperature. The preparation of the reagent, 18-Crown-6, is described by Gokel et al., Org. Syn. 57, 30 (1977).
The azido-substituted fatty acid analogs containing oxygen and/or sulfur heteroatoms in the fatty acid backbone can be synthesized by first preparing the oxygen and/or sulfur heteroatom-substituted fatty acid followed by derivatization with the azide ion. Preparation of oxa- and thia-substituted fatty acids can be carried out by methods analogous to the preparation of mixed ethers by the Williamson synthesis under phase transfer conditions. For example, an appropriate ω-bromo carboxylic acid or ester can be reacted with an alcohol or an alkyl thiol to produce, respectively, the oxa-substituted fatty acid ether or the thia-substituted fatty acid ether.
The preparation of the azido substituted fatty acid analogs of the invention are preferably carried out by the following illustrative reaction Schemes: ##STR2##
The following examples will further illustrate the invention although it will be appreciated that the invention is not limited to these specific examples. Examples 1 to 32 illustrate the synthesis of compounds according to the Reaction Schemes I to VII set forth hereinbefore. Example 33 illustrates the biological testing of representative compounds thus synthesized in (A) an in vitro yeast N-myristoyltransferase (NMT) assay and (B) a human cell culture assay to measure inhibitory activity against human immunodeficiency virus (HIV). In these examples, 18-Crown-6 refers to 1,4,7,10,13,16-hexaoxacyclooctadecane, THP refers to tetrahydropyran, THF refers to tetrahydrofuran, DMF refers to dimethylformamide and DMSO refers to dimethylsulfoxide.
EXAMPLE 1
12-azidododecanoic acid (1).
A mixture of 12-iodododecanoic acid (2.1 g, 0.0064 mol), sodium azide (1.2 g, 0.019 mol) and 18-crown-6 (0.5 g, 0.0019 mol) in dimethylformamide (25 ml) was stirred at room temperature for 16 h. After removal of the solvent under vacuum, the residue was partitioned between 1N HCl (25 ml) and dichloromethane (25 ml). The organic phase was washed with water (3×25 ml), dried (Na 2 SO 4 ) and concentrated to give a pale yellow liquid (3 g) which was purified by flash chromatography (silica gel) using 15% ethylacetate in hexane to give 12-azidododecanoic acid (1.3 g, 84%) as a colorless liquid.
1 H NMR (CDCl 3 ) δ: 3.19 (t, 2H, J=6.9 Hz, CH 2 ); 2.28 (t, 2H, J=7.5 Hz, CH 2 ); 1.53 (m, 4H, 2×CH 2 ); 1.21 (m, 14H), FABMS (m/z): 254 (M+2Li-H); 248 (M+Li) and 226.
EXAMPLE 2
11-azidoundecanoic acid (2).
The title compound was prepared in a similar manner as described for 1 except that 11-iodoundecanoic acid was substituted for an equivalent amount of 12-iodododecanoic acid. Yield 64%. 1 H NMR (CDCl 3 ) δ: 3.28 (t, 2H, J=6.8 Hz, CH 2 ); 2.35 (t, 2H, J=7.7 Hz, CH 2 ); 1.6 (m, 4H); 1.29 (m, 12H, --CH 2 ), FABMS, m/z: 228 (M+H); 200 and 182.
EXAMPLE 3
9-azidononanoic acid (3).
The title compound was prepared in a similar manner as described for 1 except that 9-iodononanoic acid was substituted for an equivalent amount of 12-iodododecanoic acid. Yield 77%. 1 H NMR (CDCl 3 ) δ: 3.26 (t, 2H, J=7.00 Hz); 2.36 (t, 2H, J=5.4 Hz); 1.62 (m, 4H); 1.33 (m, 8H), FABMS m/z: 212 (M+H) and 206 (M+Li).
EXAMPLE 4
12-iodotridecanoic acid (6).
A mixture of 12-hydroxytridecanoic acid 4 (0.3 g, 0.0013 mol), and iodotrimethylsilane (0.5 ml) in carbontetrachloride (3 ml) was stirred at room temperature for 16 h. The solution was concentrated, cold water (10 ml) was added and the mixture was extracted with ethyl acetate (2×10 ml). The organic phase was washed with water (2×15 ml), dried (Na 2 SO 4 ) and concentrated under reduced pressure. The resulting residue was purified by flash chromatography (silica gel) using 15% ethylacetate in hexane to give intermediate compound 5 (0.2 g) as a pale yellow solid. FABMS: m/z, 565 (M+2Li-H), 559 (M+Li). 5 (0.2 g) was subjected to basic hydrolysis by stirring in 1N NaOH (3 ml) and THF (2 ml) at room temperature for 16 h. The solution was cooled, acidified with 2N HCl (1.5 ml) and extracted with ethylacetate (2×10 ml). The organic phase was washed with water (2×10 ml), dried (Na 2 SO 4 ), concentrated under reduced pressure and the residue was purified by flash chromatography (silica gel) using 10% ethylacetate in hexane to give the title compound 6 (0.15 g, 34%). 1 H NMR (CDCl 3 ) δ: 3.19 (t, 2H, J=6.9 Hz); 2.35 (t, 2H, J=7.5 Hz); 1.85 (m, 2H); 1.64 (m, 2H), 1.27 (m, 16H); FABMS: m/z, 353 (M+2Li-H); 347 (M+Li) and 225. HRMS: M/Z, C 13 H 25 IO 2 Li, calc.: 275.2059; found: 275.2004 (M+Li).
EXAMPLE 5
13-azidotridecanoic acid (7).
A mixture of 6 (0.15 g, 0.44 mmol) sodium azide (0.09 g, 1.4 mmol) and 18-crown-6 (0.015 g, 0.057 mmol) in dimethylformamide (3 ml) was stirred at room temperature for 16 h. DMF was distilled under vacuum, cold 2N HCl (2 ml) was added and the mixture was extracted with ethylacetate (10 ml). The organic phase was washed with water (2×10 ml), dried (Na 2 SO 4 ) and concentrated under reduced pressure to give a pale yellow solid which was purified by flash chromatography (silica gel) using 20% ethylacetate in hexane to afford the title compound 7 (0.075 g, 67%) as a white solid. 1 H NMR (CDCl 3 ) δ: 3.26 (t, 2H, J=6.9 Hz); 2.35 (t, 2H, J=7.5 Hz); 1.62 (m, 4H); 1.35 (m, 14H), FABMS: (m/z), 256 (M+H); 230 and 210. HRMS C 13 H 25 N 3 O 2 Li calc.: 262.2107, found: 262.2164 (M+Li).
EXAMPLE 6
1-(tetrahydropyranloxy)-6-thioacetyl hexane (9).
To a solution of potassium thioacetate (0.34 g, 0.003 mol) and 18-crown-6 (0.16 g, 0.0006 mol) in DMF (5 ml), was added a solution of THP-O-(CH 2 ) 6 I 8 (0.7 g, 0.0022 mol) in DMF (2 ml). The reaction mixture was stirred at room temperature for 2 h, DMF was distilled under vacuum and the residue was partitioned between water (25 ml) and dichloromethane (25 ml). The organic phase was washed with water (2×10 ml), dried (Na 2 SO 4 ) and concentrated. The resulting material was purified by flash chromatography (silica gel) using 10% ethylacetate in hexane to give the title compound 9 (0.5 g, 86%) as a colorless liquid. 1 H NMR (CDCl 3 ) δ: 4.57 (m, 1H); 3.75 (m, 2H), 3.45 (m, 2H); 2.87 (t, 2H); 2.32 (s, 3H, --COCH 3 ); 1.75 (m, 2H); 1.6 (m, 8H); 1.39 (m, 4H), FABMS: m/z, 267 (M+Li) and 183.
EXAMPLE 7
t-butyl-5-(1-tetrahydropyranyloxy-hexane-6-thia) pentanoate (10).
A mixture of 9 (0.45 g, 0.0017 mol), t-butyl-5-bromovalerate (0.49 g, 0.002 mol) and tetrabutylammonium hydrogen sulphate (0.25 g, 0.70 mmol) was stirred vigorously in 50% sodium hydroxide (0.8 ml), toluene (2.0 ml) and THF (2.0 ml) at room temperature for 3 h and at 60° C. for 1 h. The reaction mixture was poured into ice and diluted with water (10 ml). The organic phase was washed with water (3×15 ml), dried (Na 2 SO 4 ) and concentrated to give a thick syrup, which was purified by flash chromatography (silica gel) using 10% ethyl acetate in hexane to afford the title compound 10 (0.65 g, 90%) as a colorless oil. 1 H NMR (CDCl 3 ) δ: 4.57 (m, 1H); 3.8 (m, 2H); 3.45 (m, 2H); 2.51 (m, 2H); 2.23 (t, 2 H); 1.6 (m, 12H), 1.44 (s, 9H); 1.4 (m, 8H), FABMS: m/z, 381 (M+Li); 325, 241 and 217.
EXAMPLE 8
t-butyl-5-(1-hydroxy hexyl-6-thia)pentanoate (11).
A solution of 10 (0.65 g, 0.0017 mol) in methanol (5 ml), containing p-toluenesulfonic acid (0.1 g, 0.53 mmol) was stirred at room temperature for 2 h. To this solution was added sodium bicarbonate (0.15 g) and the mixture was concentrated under reduced pressure. The residue was purified by flash chromatography (silica gel) using 15% ethylacetate in hexane to give the title compound 11 (0.36 g, 71%) as a colorless syrup. 1 H NMR (CDCl 3 ) δ: 3.65 (q, 2H); 2.51 (t, 4H); 2.23 (t, 2H); 1.6 (m, 8H); 1.44 (s, 9H); 1.40(m, 4H); 1.25 (t, 1H, --OH), FABMS: m/z, 297 (M+Li); 241 and 195.
EXAMPLE 9
t-butyl-5-(1-iodo-hexane-6-thia)pentanoate(12).
A mixture of 11 (0.35 g, 0.0012 mol) and methyltriphenoxyphosphonium iodide (0.7 g, 0.0015 mol) in acetonitrile (5 ml) was stirred at room temperature for 2.5 h. After removal of the solvent, the residue was dissolved in dichloromethane (25 ml) and a cold solution of 0.5N NaOH was added. The organic phase was washed with water (3×15 ml), dried (Na 2 SO 4 ), concentrated under reduced pressure and the residue was purified by flash chromatography using 3% ethylacetate in hexane to yield the title compound 12 (0.49, 83%) as a colorless liquid. 1 H NMR (CDCl 3 ) δ: 3.39 (m, 4H); 3.19 (t, 2H); 2.34 (t, 2H); 1.75 (m, 2H); 1.6 (m, 6H); 1.44 (s, 9H); 1.39 (m, 4H), FABMS: m/z, 407 (M+Li); 401 (M+H); 345, 327 and 217.
EXAMPLE 10
5-(1-azido-hexane-6-thia)pentanoic acid (13).
A mixture of 12 (0.36 g, 0.9 mmol) and iodotrimethylsilane (0.2 ml) in carbontetrachloride (3.0 ml) was stirred at room temperature for 4 h. The solution was cooled, cold water (10 ml) was added and the mixture extracted with carbontetrachloride (2×5 ml). The organic phase was successively washed with 5% sodium sulphite (5 ml), water (3×10 ml) and dried (Na 2 SO 4 ). The solution was concentrated under reduced pressure and dried under vacuum to give 0.16 g of a thick syrup. This product was dissolved in dimethylformamide (2 ml), to which was added sodium azide (0.096 g, 0.0015 mol) and 18-crown-6 (0.01 g) and then stirred at room temperature for 16 h. The solvent was distilled under vacuum, 1N HCl (10 ml) was added and the mixture was extracted with ethylacetate (2×10 ml). The organic phase was washed with water (2×10 ml), dried (Na 2 SO 4 ), concentrated and the residue was purified by flash chromatography (silica gel) using 15% ethylacetate in hexane to afford the title compound 13 (0.07 g, 58%) as a colorless liquid, 1 H NMR (CDCl 3 ) δ: 3.27 (t, 2H); 2.51 (m, 4H); 2.39 (t, 2H); 1.7 (m, 8H); 1.4 (m, 4H), FABMS: m/z, 272 (M+2Li-H); 266 (M+Li) and 244. HRMS: m/z, CH 11 H 21 N 3 SO 2 Li, calc: 266.1516, found: 266.1491 (M+Li).
EXAMPLE 11
Methyl-2-(1-terahydropyranyloxy-nonane-9-thia)acetate (15).
To a solution of THP-O-(CH 2 ) 9 I 14 (0.23 g, 0.65 mmol) and methyl thioglycolate (0.1 g, 0.94 mmol) in acetonitrile, was added triethylamine (0.17 ml, 1.2 mmol) was added and the mixture was stirred at room temperature for 2 h. The solution was concentrated, water (10 ml) was added and the mixture was extracted with ethylacetate (2×10 ml). The organic phase was washed with water (2×10 ml), dried (Na 2 SO 4 ), concentrated under reduced pressure and the residue was purified by flash chromatography (silica gel) using 5% ethylacetate in hexane to give the title compound 15 (0.2 g, 92%) as a colorless oil. 1 H NMR (CDCl 3 ) δ: 4.57 (m, 1H); 3.85 (m, 1H), 3.74 (s, 3H); 3.71 (m, 1H); 3.5 (m, 1H); 3.4 (m, 1H); 3.2 (s, 2H, -- OCH 2 ), 2.62 (t, 2H); 1.75 (m, 2H); 1.57 (m, 8H); 1.3 (m, 1OH). FABMS; m/z, 339 (M+Li); 249 and 231.
EXAMPLE 12
Methyl-2-(1-hydroxynonane-9-thia)acetate (16).
The tetrahydropyranyl group in 15 (0.2 g, 0.6 mmol) was cleaved using p-toluenesulfonic acid in a similar manner as described for cleavage of the THP group in 10 in Example 8 to provide the title compound 16 Yield 0.14 g (93%). 1 H NMR (CDCl 3 ) δ: 3.74 (s, 3H, OCH 3 ); 3.65 (q, 2H); 3.23 (s, 2H, --OCH 2 ); 2.63 (t, 2H); 1.6 (m, 4H); 1.3 (m, 10H); 0.9 (t, 1H). FABMS: m/z, 255 (M+Li).
EXAMPLE 13
Methyl-2-(1-iodo-nonane-9-thia)acetate (17).
The title compound 17 was prepared by the iodination of 16 (0.27 g, 1.1 mmol) using methyltriphenoxyphosphonium iodide in a manner similar to that described for the preparation of 12 in Example 9. Yield 0.24 g, 62%. 1 H NMR (CDCl 3 ) δ: 3.74 (s, 3H, OCH 3 ); 3.23 (s, 2H, --OCH 2 ); 3.19 (t, 2H); 2.63 (t, 2H); 1.82 (m, 2H); 1.60 (m, 2H); 1.33 (m, 10H). FABMS: m/z, 365 (M+Li), 359 (M+H) and 237.
EXAMPLE 14
Methyl-2-(1-azidononane-9-thia)acetate (18).
A mixture of 17 (1.5 g, 4.2 mmol), sodium azide (0.5 g, 7.7 mmol) and 18-crown-6 (0.12 g, 0.45 mmol) in dimethylformamide (5 ml) was stirred at room temperature for 16 h. The solution was concentrated under high vacuum and the residue was partitioned between water (10 ml) and dichloromethane (15 ml). The organic phase was washed with water (3×10 ml), dried (Na 2 SO 4 ), concentrated and the residue was purified by flash chromatography using 5% ethylacetate in hexane to furnish the title compound 18 (1.04 g, 83%) as a colorless liquid. 1 H NMR (CDCl 3 ) δ: 3.74 (s, 3H, OCH 3 ); 3.26 (t, 2H); 3.23 (s, 2H, OCH 2 ); 2.63 (t, 2H), 1.59 (m, 4H); 1.31 (m, 10H). FABMS: m/z, 280 (M+Li) and 252.
EXAMPLE 15
2-(1-azidononane-9-thia)acetic acid (19).
A solution of 18 (0.54 g, 2 mmol) in 1N methanolic sodium hydroxide (8 ml) and THF (2 ml) was stirred at room temperature for 4 h. The reaction mixture was concentrated to dryness, water (10 ml) was added, and the mixture was neutralized with 2N HCl (4 ml) and extracted with dichloromethane (2×10 ml). The organic layer was washed with water (2×10 ml), dried (Na 2 SO 4 ), concentrated and the residue was purified by flash chromatography using 25% ethylacetate in hexane to afford the title compound 19 (0.4 g, 78%) as a colorless liquid. 1 H NMR (CDCl 3 ) δ: 3.28 (t, 2H); 3.28 (s, 2H, --OCH 2 ); 69 (t, 2H); 1.63 (m, 4H); 1.38 (m, 10H) 13 C NMR (CDCl 3 ) δ: 26.62, 28.59, 28.77, 28.81, 28.97, 29.24, 32.74, 33.47, 51.42 and 176.95. FABMS: (m/z), 272 (M+2Li-H); 266 (M+Li); 244 and 238. HRMS: m/z, C 11 H 21 N 3 O 2 Li, calc: 266.1516, found: 266.1502 (M+Li).
EXAMPLE 16
4-(1-iodooctane-8-thia)propionic acid (22).
A mixture of diiodooctane 20 (2.8 g, 7.65 mmol), 3-mercaptopropionic acid 21 (0.75 ml, 8.6 mmol), dimethylaminopyridine (0.1 g, 0.82 mmol) and triethylamine (2.4 ml, 17.1 mmol) in acetonitrile (20 ml) was stirred at room temperature for 16 h. After removal of the solvent under reduced pressure, the residue was partitioned between 1N HCl (25 ml) and dichloromethane (25 ml). The organic phase was washed with water (3×15 ml), dried (Na 2 SO 4 ), concentrated under reduced pressure and the residue was purified by flash chromatography (silica gel) using 20% ethylacetate in hexane to give the title compound 22 (0.3 g, 11%) as a low melting solid. 1 H NMR (CDCl 3 ) δ: 3.19 (t, 2H, 6.9 Hz); 2.78 (m, 2H); 2.66 (m, 2H); 2.54 (m, 2H); 1.82 (m, 2H); 1.6 (m, 2H); 1.33 (m, 8H). FABMS: m/z, 357 (m+2Li-H); 351 (M+Li); 223 (M+Li-HI). HRMS: m/z, C 11 H 21 IO 2 SLi, calc: 351.0467, found: 351.0484 (M+Li).
EXAMPLE 17
4-(1-azidooctane-6-thia)propionic acid (23).
The title compound 23 was obtained by stirring a solution of 22 in DMF containing sodium azide and 18-crown-6 in a similar manner as described for the preparation of compound 1 in Example 1. Yield 66%. 1 H NMR (CDCl 3 ) δ: 3.26 (t, 2H); 2.77 (t, 2H); 2.67 (t, 2H); 2.54 (t, 2H); 1.59 (m, 4H); 1.33 (m, 8H). 13 C NMR (CDCl 3 ) δ: 26.58; 26.60; 28.66; 28.77; 28.97; 28.99; 29.41; 32.13; 34.69; 51.42, 178.15. FABMS: m/z, 272 (M+Li-H); 266 (M+Li); 244 and 229. HRMS: m/z, C 11 H 21 N 3 O 2 SLi, calc: 266.1516, found: 266.1510 (M+Li).
EXAMPLE 18
t-butyl-9-(1-tetrahydropyranyloxy-ethane-2-oxa)nonanoate (32).
A mixture of 24 (0.97 g, 0.0066 mol) and 28 (1.2 g, 0.004 mol) in 50% aqueous NaOH (2.7 ml) and toluene (3.0 ml) containing tetrabutylammoniumhydrogen sulfate (0.25 g, 0.74 mmol) was stirred at room temperature for 16 h. The reaction mixture was poured into cold water (15 ml) and extracted with ethylacetate (3×15 ml). The organic phase was washed with water (3×15 ml), dried (Na 2 SO 4 ) and concentrated under reduced pressure to give 1.5 g of liquid which was purified (twice) by flash chromatography (silica gel) using 10% EtOAc in hexane containing 0.2% Et 3 N to give 0.73 g (50%) of the title compound 32 as a colorless liquid. 1 H NMR (CDCl 3 ) δ: 4.64 (m, 1H); 3.85 (m, 2H); 3.60 and 3.47 (m, 6H); 2.19 (t, 2H, J=7.2 Hz); 1.8 (m, 2H); 1.56 (m, 8H); 1.44 (s, 9H); 1.29 (bs, 8H). FABMS: m/z, 365 (M+Li), 309, 225 and 201.
EXAMPLE 19
t-butyl-8-(1-tetrahydropyranyloxy-propane-3-oxa)octanoate (33).
The title compound 33 was prepared from 25 and 29 in a manner similar to the preparation of 32 in Example 18. Yield 41%. 1 H NMR (CDCl 3 ) δ: 4.58 (m, 1H); 3.83 (m, 2H); 3.52, 3.40 (2m, 6H); 2.22 (t, 2H); 1.86 (m, 2H); 1.55 (m, 10H); 1.44 (s, 9H); 1.31 (m, 6H). FABMS: m/z=365 (M+Li), 309 and 275. HRMS: m/z, C 20 H 38 O 5 Li, calc: 365.2879, found: 365.2870 (M+Li).
EXAMPLE 20
t-butyl-5-(1-tetrahydropyranyloxy-hexane-6-oxa-pentanoate (34).
To an ice-cold solution of 26 (0.7 g, 0.0035 mol) and t-butyl-5-bromovalerate 30 (0.6 g, 0.0029 mol) in toluene (2 mL), 50% aq. NaOH solution (1.4 mL) and tetrabutylammonium hydrogen sulfate (0.12 g, 0.35 mmol) were added. The resulting mixture was stirred for 30 min. at 0° C. and then for 4 h at room temperature. The reaction was poured into 10 mL of ice-water and extracted with EtOAc (2×15 mL). The organic phase was washed with water (3×15 mL), dried (Na 2 SO 4 ) and concentrated in vacuo to afford a pale, yellow liquid (1.1 g) which was purified by flash chromatography using 20% EtOAc in hexane containing 0.2% Et 3 N as the eluent. The unreacted bromovalerate 30 (0.31 g, 46%) eluted first, followed by the title compound 34. The chromatography fractions containing 12 were combined, concentrated, and dried under high vacuum to afford 0.34 g of 34 (32%) as a colorless oil. R f 0.63 (50% EtOAc in hexane). 1 H NMR, 4.56 (t, 1H); 3.87 (m, 1H); 3.75 (m, 1H); 3.39 (m, 6H); 2.24 (t, 2H), 1.3-1.9 (m, 27H). FABMS: m/z 376 (M+NH 4 ). HRMS: m/z, C 20 H 38 O 5 Li, calc: 365.2879, found: 365.2901.
EXAMPLE 21
t-butyl-2-(1-tetrahydropyranyloxy-nonane-9-oxa)acetate (35).
The title compound was prepared in a manner similar to the preparation of compound 32 in Example 18. Yield 64%.
1 H NMR (CDCl 3 ) δ: 4.58 (m, 1H); 3.9 (s, 2H); 3.85 and 3.75 (m, 2H); 3.5 (t, 2H); 3.39 (m, 2H); 1.58 (m, 10H); 1.48 (s, 9H); 1.31 (m, 10H). FABMS: m/z=365 (M+Li), 309 and 225.
EXAMPLE 22
t-butyl-9-(1-iodo-ethane-2-oxa)nonanoate (36).
A solution of 32 (0.7 g, 2.0 mmol) in methanol (3 ml) containing p-toluenesulfonic acid (0.1 g, 0.53 mmol) was stirred at room temperature for 1 h, NaHCO 3 (0.1 g) was added and the mixture was concentrated. The residue was purified by flash chromatography (silica gel) using 25% EtOAc in hexane to give 0.52 g of a colorless liquid. This product was dissolved in acetonitrile (7 ml), methyltriphenoxy phosphonium iodide (1.15 g, 2.5 mmol) was added and the mixture was stirred at room temperature for 4 h. The reaction mixture was concentrated to dryness, water (15 ml) was added and the mixture was extracted with ethylacetate (3×15 ml). the organic phase was washed with 5% sodium thiosulphate (10 ml) water (3×15 ml), dried (Na 2 SO 4 ) and concentrated. The residue was purified by flash chromatography (silica gel) using 4% ethylacetate in hexane to give the title compound 36 (0.46 g, 66%) as a colorless liquid.
1 H NMR (CDCl 3 ) δ: 3.68 (t, 2H); 3.47 (t, 2H); 3.25 (t, 2H); 2.2 (t, 2H); 1.55 (m, 4H); 1.44 (s, 9H); 1.31 (m, 8H). FABMS: m/z=391 (M+Li), 335, 329 and 253. HRMS: m/z, C 15 H 29 IO 3 Li, calc. 391.1322, found 391.1364 (M+Li).
EXAMPLE 23
t-butyl-8-(1-iodo-propane-3-oxa)octanoate (37).
The title compound 37 was prepared from 33 in a manner similar to the preparation of compound 36 in Example 22. Yield 65%. 1 H NMR (CDCl 3 ) δ: 3.44 (m, 4H); 3.28 (t, 2H J=6.9 Hz); 2.2 (t, 2H, J=7.5Hz); 2.05 (m, 2H); 1.58 (m, 4H); 1.44 (s, 9H); 1.32 (m, 6H), FABMS: m/z, 391 (M+Li), 335. HRMS: m/z, C 15 H 29 IO 3 Li, calc: 391.1322, found: 391.1353 (M+Li).
EXAMPLE 24
t-butyl-5-(1-iodo-hexane-6-oxa)pentanoate (38).
The title compound 38 was prepared from 34 in a manner similar to the preparation of compound 36 in Example 22. Yield 77%. 1 H NMR (CDCl 3 ) δ: 3.39 (m, 4H); 3.19 (t, 2H, J=6.9Hz); 2.24 (t, 2H); 1.85 (m, 2H); 1.6 (m, 6H); 1.49 (s, 9H); 1.39 (m, 4H). FABMS: m/z 391 (M+Li); 335 and 211. HRMS: m/z, C 15 H 29 IO 3 Li, calc: 391.1322, found: 391.1374 (M+Li).
EXAMPLE 25
t-butyl-2-(1-iodo-nonane-9-oxa)acetate (39).
The title compound 39 was prepared from 35 in a manner similar to the preparation of 36 in Example 22. Yield 69%. 1 H NMR (CDCl 3 ) δ: 3.95 (s, 2H); 3.5 (t, 2H); 3.19 (t, 2H); 1.8 (m, 2H); 1.6 (m, 2H), 1.48 (s, 9H); 1.3 (m, 10H). FABMS: m/z, 391 (M+Li); 335, 329, 283 and 253.
EXAMPLE 26
9-(1-azido-ethane-2-oxa)nonanoate (40).
A solution of 36 (0.45 g, 1.2 mmol) and iodotrimethylsilane (0.25 ml) in carbontetrachloride (3 mol) was stirred at room temperature for 1.5 h. The solution was concentrated under reduced pressure, 0.5N HCl (5 ml) and dichloromethane (15 ml) were added. The organic phase was washed with water (3×10 ml), dried (Na 2 SO 4 ), concentrated and the residue was dried in vacuo to give 0.36 g. This product was dissolved in DMF (5 ml), sodium azide (0.24 g, 3.7 mmol) and 18-Crown-6 (0.025, 0.095 mmol) were added and the mixture was stirred at room temperature for 6 h. The solution was concentrated, 0.5N HCl (5 ml) was added and the mixture was extracted with ethylacetate (2×10 ml). The organic phase was washed with water (2×15 ml), dried (Na 2 SO 4 ), concentrated under reduced pressure, and the residue was purified by flash chromatography (silica gel) using 20% EtOAc in hexane to give the title compound 40 (0.19 g, 64%) as a colorless liquid. 1 H NMR (CDCl 3 ) δ: 3.6 (t, 2H), 3.47 (t, 2H); 3.38 (t, 2H); 2.35 (t, 2H, J=7.5 Hz); 1.61 (m, 4H); 1.32 (m, 8H); 13 C NMR (CDCl 3 ) δ: 24.60; 25.86; 28.91; 29.09, 29.13; 29.53; 34.02; 50.72; 69.44; 71.39, 180.09. FABMS: m/z=261 (M+NH 4 + ); 244 (M+H). HRMS: m/z=C 11 H 21 N 3 O 3 Li, calc: 250.1743, found: 250.1731 (M+Li).
EXAMPLE 27
8-(1-azido-propane-3-oxa)octanoic acid (41).
The title compound 41 was prepared in a similar manner as compound 40 in Example 26 except that reactant compound 37 was substituted for an equivalent amount of 36. Yield 65%. 1 H NMR (CDCl 3 ) δ: 3.48 (t, 2H, J=6.0 Hz); 3.41 (m, 4H); 2.35 (t, 2H, J=7.5 Hz); 1.84 (m, 2H); 1.6 (m, 4H); 1.34 (m, 6H). 13 C NMR (CDCl 3 ) δ: 24.42, 25.76, 28.59, 29.05, 29.37, 33.81, 33.86, 48.36, 67.11, 70.92, 179.88. FABMS: m/z=261 (M+NH 4 + ); 244 (M+H) and 216. HRMS: m/z=C 11 H 21 N 3 O 3 Li, calc: 250.1743, found: 250.1702 (M+Li).
EXAMPLE 28
5-(1-azido-hexane-6-oxa)pentanoic acid (42).
The title compound 42 was prepared in a similar manner as compound 40 in Example 26 except that reactant compound 38 was substituted for an equivalent amount of 36. Yield 73%. 1 H NMR (CDCl 3 ) δ: 3.4 (m, 4H), 3.29 (t, 2H, J=6.9 Hz); 2.4 (t, 2H, J=7.2Hz); 1.65 (m, 8H); 1.39 (m, 4H). FABMS: m/z: 261 (M+NH 4 + ); 244 (M+H) and 216. HRMS: m/z=C 11 H 21 N 3 O 3 Li, calc: 250.1743, found: 250.1779 (M+Li).
EXAMPLE 29
2-(1-azido-nonane-9-oxa)acetic acid (43).
The title compound 43 was prepared in a similar manner as compound 40 in Example 26 except that reactant compound 39 was substituted for an equivalent amount of 36. Yield 50%. 1 H NMR (CDCl 3 ) δ: 4.09 (s, 2H, OCH 2 ); 3.58 (t, 2H, J=6.6 Hz); 3.26 (t, 2H, J=7.2 Hz); 1.61 (m, 4H); 1.32 (m, 10H). FABMS: m/z=250 (M+Li) and 228. HRMS: m/z=C 11 H 21 N 3 O 3 Li, calc: 250.1743, found: 250.1741 (M+Li).
EXAMPLE 30
12-(tetrazolyl)dodecanoic acid (46).
A suspension of NaH (0.045 g, 80% suspension in oil) in DMF (1 ml) was added to a solution of tetrazole 44 (0.095 g, 1.35 mmmol) in DMF (1 ml). After stirring the reactants for 15 min, a solution of 12-iodo-dodecanoic acid 45 (0.2 g, 0.6 mmol) was added. The resulting mixture was stirred at room temperature for 1 h and at 55° C. for 1.5 h and then concentrated in vacuo. The residue was treated with 1N HCl(5 ml) and extracted with EtOAc (2×10 ml). The organic layer was washed with water, dried (Na 2 SO 4 ), concentrated under reduced pressure and the residue was crystallized from EtOAc/Hexane to give the title compound 46 (0.095 g, 26%) as a 1:3 mixture of N-3 and N-1 isomers, respectively. This mixture was tested directly as a substrate for NMT. 1 H NMR (CDCl 3 ) δ: 8.59 and 8.5 (2s, 1H); 4.65 and 4.43 (2t, 2H, J=7.2 Hz); 2.35 (t, 2H, J=7.5 Hz); 1.95 (m, 2H); 1.63 (m, 2H); 1.26 (m, 14H). FABMS: m/z 269 (M+H); 251 and 241. HRMS: m/z=C 13 H 24 N 4 O 2 Li, calc: 275.2059, found: 275.2004 (M+Li).
EXAMPLE 31
12-[1,2,4]triazolycdodecanoic acid (48).
To a suspension of sodium hydride (0.05 g, of 80% suspension in oil) in DMF cooled to 0° C., was added dropwise a solution of 1,2,4-triazole 47 (0.095 g, 1.38 mmol) in DMF (1.5 ml). The reaction mixture was stirred at 0° C. for 30 min., a solution of 12-iodododecanoic acid 45 (0.2 g, 0.6 mmol) and 18-crown-6 (0.01 g, 0.038 mmol) in DMF (1 ml), was added, and stirred at room temperature for 1 h and at 60° C. for 1.5 h. DMF was distilled under reduced pressure, the residue was dissolved in water (5 ml), acidified with 1N HCl to pH6 and extracted with ethyl acetate (2×15 ml). The organic phase was washed with water (2×10 ml), dried (Na 2 SO 4 ) and concentrated under reduced pressure. The residue was purified by crystallization from ethyl acetate hexane (1:1) to give 48 (0.055 g, 34%) as a white powder. 1 H NMR (CDCl 3 ) δ: 8.10 (s, 1H), 7.96 (s, 1H), 4.17 (t, 2H, J=7.2Hz), 2.35 (t, 2H, J=7.5 Hz); 1.88 (m, 2H), 1.63 (m, 2H), 1.26 (m, 14H). FABMS: m/z=268 (M+H).
EXAMPLE 32
12-(N-2-[1,2,3]triazolyl)dodecanoic acid (50).
To a suspension of sodium hydride (0.13 g, of 80% suspension in oil) in DMF (4 ml) cooled to 0° C., was added dropwise a solution of 1,2,3-triazole 49 (0.28 g, 0.004 mmol) in DMF (1 ml). After 0.5 h, 18-crown-6 (0.025 g, 0.095 mmol) and 12-iodododecanoic acid 45 (0.5 g, 0.0016 mol) were added and the mixture was stirred for 1 h at room temperature and 1.5 h at 60° C. under nitrogen atmosphere. The reaction mixture was concentrated under vacuum, the residue was dissolved in water (10 ml), acidified with cold 1N HCl and the resulting mixture was extracted with ethyl acetate (3×15 ml). The organic phase was washed with water (2×10 ml), dried (Na 2 SO 4 ), concentrated under reduced pressure and the residue was crystallized from ethyl acetate to afford the title compound 50 (0.12 g, 28%) as a white crystalline substance. m.p. 79°-80° C.; 1 H NMR (CDCl 3 ) δ: 7.59 (s, 2H), 4.44 (t, 2H, J=7.2 Hz); 2.35 (t, 2H, J=7.2 Hz), 1.95 (m, 2H); 1.63 (m, 2H), 1.26 (m, 14H). FABMS: m/z=274 (M+Li). HRMS: m/z=C 14 H 25 N 3 O 2 Li, calc: 274.2107, found: 274.2105.
EXAMPLE 33
A. Representative compounds prepared in the foregoing illustrative specific examples were analyzed in a conventional in vitro yeast N-myristoyltransferase (NMT) assay as published by Heuckeroth et al., Proc. Nat'l. Acad. Sci. USA 85, 8795-8799 (1988). In this assay, the test compounds were first converted to their respective fatty acyl CoA derivatives and then tested as substrates for the yeast NMT.
The assay conditions [essentially the same as those reported by Towler and Glaser, Proc. Natl. Acad. Sci. USA 83, 2812-2816 (1986)] were as follows:
1. Ligase reaction: 3.3 μmoles fatty acid, 5 mM ATP and 1 mM CoA were incubated with 15-150 milliunits of CoA ligase (1 unit/ml in 50 mM HEPES, pH 7.3) in a buffer composed of 10 mM TRIS-HCl, pH 7.4, 1 mM dithiothreitol, 5 mM MgCl 2 and 0.1 mM EGTA, in a total volume of 50 μl for 25 minutes at 30° C.
2. NMT assay: 50 μl of the CoA ligase mixture was added to a 50 μl solution of 90 μM peptide (GSAASARR-NH 2 ) in a buffer composed of 10 mM TRIS-HCl, pH 7.4, 1 mM dithiothreitol, 0.01 mM EGTA and aprotinin (10 μg/ml). 0.4 Unit of yeast N-myristoyltransferase was then added and the reaction mixture was incubated at 30° C. for 10 minutes. The peptide was radiolabeled with tritiated alanine in position 3. The reaction was quenched with 120 μl of TCA-MeOH and 75 μl was injected on a reverse phase C18 HPLC column and eluted with a linear gradient of 0-100% acetonitrile over 100 minutes (both water and acetonitrile containing 0.1% trifluoroacetic acid). Radioactivity was assessed with an on line radiomatic detector corrected for quenching.
The amount of radioactivity was determined for each azido-substituted fatty acyl peptide product and then was normalized to the amount of myristoyl peptide produced in an assay run in parallel.
The activity of each fatty acid analog was thus expressed as a percentage of the activity exhibited by unsubstituted myristate (control) and recorded in the following Table 1.
TABLE 1______________________________________Substrate Activity of Azido-Substituted Fatty Acid AnalogsSynthesis ActivityExample Test Myristate Analog (% ofCompound Test Compound Myristate)______________________________________Example 1 N.sub.3 (CH.sub.2).sub.11 COOH (1) 142Example 2 N.sub.3 (CH.sub.2).sub.10 COOH (2) 100Example 3 N.sub.3 (CH.sub.2).sub.8 COOH (3) 55Example 26 N.sub.3 (CH.sub.2).sub.2 --O--(CH.sub.2).sub.8 COOH 280)Example 27 N.sub.3 (CH.sub.2).sub.3 --O--(CH.sub.2).sub.7 COOH 421)Example 28 N.sub.3 (CH.sub.2).sub.6 --O--(CH.sub.2).sub.4 COOH 622)Example 29 N.sub.3 (CH.sub.2).sub.9 --O--CH.sub.2 COOH (43) 11Example 10 N.sub.3 (CH.sub.2).sub.6 --S--(CH.sub.2).sub.4 COOH 103Example 13 N.sub.3 (CH.sub.2).sub.9 --S--CH.sub.2 COOH (19) 17Example 23 N.sub.3 (CH.sub.2).sub.8 --S--(CH.sub.2).sub.2 COOH 373)Example 30 Tetrazolyl-(CH.sub.2).sub.11 COOH (46) 46Example 31 1,2,4-Triazoyl-(CH.sub.2).sub.11 COOH (48) 23Example 32 1,2,3-Triazoyl-(CH.sub.2).sub.11 --COOH (50) 99______________________________________
B. Representative compounds prepared in the foregoing illustrative specific examples were also tested in vitro for the assessment of anti-viral (HIV) activity as follows:
ASSAY INFORMATION
The HIV inhibition assay method of acutely infected cells is an automated tetrazolium based colorimetric assay adapted from that reported by Pauwles et al., J. Virol. Methods, 20, 309-321 (1988). Assays were performed in 96-well tissue culture plates. CEM cells were grown in RPMI-1640 medium (Gibco) supplemented with 10% fetal calf serum and were then treated with polybrene (2 μg/ml). An 80 μl volume of medium containing 1×10 4 cells was dispensed into each well of the tissue culture plate. To each well was added a 100 μl volume of test compound dissolved in tissue culture medium (or medium without test compound as a control) to achieve the desired final concentration and the cells were incubated at 37° C. for 1 hour. A frozen culture of HIV-1 was diluted in culture medium to a concentration of 5×10 4 TCID 50 per ml (TCID 50 =the dose of virus that infects 50% of cells in tissue culture), and a 20 μl volume of the virus sample (containing 1000 TCID 50 of virus) was added to wells containing test compound and to wells containing only medium (infected control cells). This results in a multiplicity of infection of 0.1 (MOI=# of infectious virus particles/# of cells in culture). Several wells received culture medium without virus (uninfected control cells). Likewise, the intrinsic toxicity of the test compound was determined by adding medium without virus to several wells containing test compound. In summary, the tissue culture plates contained the following tests (in triplicate):
______________________________________cells drug virus______________________________________1. + - - uninfected cell control2. + + - uninfected drug control3. + - + infected cell control4. + + + test case______________________________________
In tests 2 and 4 the final concentrations of test compounds were 1, 10, 100 and 500 μg/ml. Azidothymidine (AZT) was tested as a positive drug control, and dodecanoic acid was tested as a negative fatty acid control. Test compounds were dissolved in DMSO and diluted into tissue culture medium so that the final DMSO concentration did not exceed 1.5% in any case. Under these conditions, DMSO had no significant effect on results as determined in controls.
Following the addition of virus, cells were incubated at 37° C. in a humidified, 5% CO 2 atmosphere for 7 days. Additional aliquots of test compounds were added on days 2 and 5. On day 7 post-infection, the cells in each well were resuspended and a 100 μl sample of each cell suspension was removed for assay. A 20 μl volume of a 5 mg/ml solution of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was added to each 100 μl cell suspension, and the cells were incubated for 4 hours at 37° C. in a 5% CO 2 environment. During this incubation, MTT is metabolically reduced by living cells resulting in the production in the cell of a colored formazan product. To each sample was added 100 μl of 10% sodium dodecylsulfate in 0.01 N HCl to lyse the cells and samples were incubated overnight. The absorbance of each sample was determined at 590 nm using a Molecular Devices microplate reader. The % reduction of the virus induced cytopathic effect (CPE) by the test compounds was determined using the formula shown at the bottom of Table 2, hereinafter.
The results of the antiviral testing are set forth in Table 2, as percent reduction in cytopathic effect (CPE). The inhibitory dose that inhibits 50% of the cytopathic effect is shown as ID 50 (μg/ml).
TABLE 2______________________________________Antiviral Evaluation of Myristate AnalogsPercent Reduction of CPE.sup.a Concentration μCompound 100 10 1 ID.sub.50 (μg/ml)______________________________________3-Oxamyristate T 43.5.sup.c 66.4 0.3 Positive controlDecanoic acid T 11.3 7.7 -- Negative(C.sub.10).sup.b control12-Azidododecanoic T 38.2.sup.c 81.7 0.3acid (1)11-Azidoundecanoic T 34.6.sup.c 16.3 --acid (2)12-Azido-9-oxa-DDA (41) -- 66 14 512-Azido-3-oxa-DDA (43) -- -- -- Inactive12-Azido-6-oxa-DDA (42) -- 20 4 Inactive12-azido-3-thia-DDA (19) T 54 1 9.212-azido-4-thia-DDA (23) T 0 0 Inactive12-azido-6-thia-DDA (13) T 14 0 Inactive12-tetrazoyl-DDA (46) -- 65 12 5.912-(1,2,4-triazoyl)-DDA (48) T 66 24 4.212-(1,2,3-triazoyl)-DDA (50) T 30.8 19.5 --______________________________________Com- 0.001 ID.sub.50pound 0.5 μ/ml 0.1 μg/ml 0.01 μg/ml μg/ml (μg/ml)______________________________________AZT 87.8 100.8 84.8 58.2 <0.001______________________________________ DDA = Dodecanoic acid .sup.a The percent reduction of viral CPE was calculated by the formula: ##STR3## .sup.b Solubility problem; precipitate at highest test concentration. .sup.c Value may be artificially low because of partial toxicity at this test concentration.
The biologically active fatty acid analogs described herein can be used for administration to a mammalian host or host cells infected with retroviruses such as HIV and the like by conventional means, preferably in formulations with pharmaceutically acceptable diluents and carriers. The amount of the active agent to be administered must be an effective amount, that is, an amount which is medically beneficial but does not present toxic effects which overweigh the advantages which accompany its use. It would be expected that the adult human dosage would normally range upward from about one milligram of the active compound. A suitable route of administration is orally in the form of capsules, tablets, syrups, elixirs and the like, although parenteral administration also can be used. Appropriate formulations of the active compound in pharmaceutically acceptable diluents and carriers in therapeutic dosage form can be prepared by reference to general texts in the field such as, for example, Remington's pharmaceutical sciences, Ed. Arthur Osol, 16th ed., 1980, Mack Publishing Co., Easton, Pa.
Various other examples will be apparent to the person skilled in the art after reading the present disclosure without departing from the spirit and scope of the invention. All such other examples are included within the scope of the appended claims.
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Azido-substituted fatty acid analogs which are useful in the fatty acid acylation of peptides and proteins and as antiviral agents are disclosed having the following chemical structure:
Z--(CH.sub.2).sub.x COOR
wherein
Z=azido, tetrazolyl or triazolyl
R=H or C 1 -C 8 alkyl, and
x=8-12.
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RELATED APPLICATION
[0001] This application claims the priority of U.S. Provisional Patent Application Nos. 60/938,953, filed May 18, 2007, and 60/956,246, filed Aug. 16, 2007, the complete disclosures of which are both hereby expressly incorporated by reference.
BACKGROUND
[0002] The present disclosure relates to beverage making equipment, namely, beverage making equipment which utilizes heated water and dispenses heated water from a heated water reservoir to a beverage making substance.
[0003] A variety of beverage making devices utilize a heated water reservoir to retain a volume of water in a heated condition for use in making beverages. Water can be controllably dispensed from the reservoir to a holder or container which contains a quantity of beverage making substance. The heated water is combined with the beverage making substance to produce a beverage. In such a beverage making machine, the reservoir can operate in a gravity feed mode of operation or a pressurized mode of operation. Also, one of the conditions associated with the heating of water is the evolution or out-gassing of gas which might be retained in the water. For example, at lower temperatures the water may have some portion of gas dissolved into the water. Heating may release the gas or otherwise evolve the gas through chemical processes. One of the problems with the gas which is created during the heating of the water is that it can be introduced into the beverage making process. Introduction of gas to the beverage making process has little or no currently known direct effect on the beverage making substance or the beverage produced thereby. The gas, however, can have an effect on the beverage making process.
[0004] Gas which evolves or otherwise comes out of the water in the reservoir may be vented through a venting device on the reservoir. If the reservoir does not include a venting device or if the gas evolves in other components of the reservoir and beverage making apparatus the gas may accumulate and interfere with the dispensing of heated water from the reservoir. In this regard, a line or tube is connected to the reservoir and extends from the reservoir to a spray head which dispenses the heated water over the beverage making substance in the holder. Gas may evolve in the line or may be introduced into the line and if retained in the line in sufficient quantity may introduce a variable which could have a negative effect on the brewing process.
[0005] Gas introduced into the line and retained in the line may be inconsistent, may break up or pass through the line and reform, or other undesirable conditions. Regardless, the presence of gas in the line can be problem because it reduces the flow volume through the line. The reduction in flow volume through the line is detrimental to the brewing process since the machine may be configured to dispense a volume of water based on the time a valve associated with the dispensing process is opened. In other words, at least one valve is provided in the process for control of water through the heated water reservoir. In this regard, if the time of the valve opening is held generally consistent the expectation would be that a generally consistent volume of water would be dispensed. However, if a portion of the dispense line is blocked, obstructed or otherwise occupied by gas, the volume dispensed will be inconsistent with the expected volume dispensed. Further, the volume dispensed will be inaccurate or may be in accurate as a result of the bubble forming, passing through, reforming and presenting indifferent gas volumes during different brew cycles. The existence of gas in the line introduces a variable which is not controllable. The variable can introduce inconsistencies in the beverage brewed since the characteristics of the brewed beverage are directly related to the volume of water used in the brewing process.
[0006] Further, inaccurate dispensing of water may introduce cost inefficiencies. While the cost and efficiency per cycle may be somewhat nominal, cumulatively the cost and efficiencies can be somewhat significant. In this regard, shorting a brewing cycle of the amount of water will reduce the number of cups produced. Reducing the number of cups produced per charge of beverage making substance, will reduce the profit produced. Again, while this may not seem significant on a per cycle basis, cumulatively, for exampled over numerous franchise operations, this could be a significant number. The reduction and the inconsistencies in the water flowing through the line can be reduced by eliminating the gas accumulation in the line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The organization and manner of the structure and function of the disclosure, together with the further objects and advantages thereof, may be understood by reference to the following description taken in connection with the accompanying drawings, and in which:
[0008] FIG. 1 is a simplified generally diagrammatic illustration of a heated water reservoir showing a line connected to the heated water reservoir and a corresponding spray head to show a relationship between the reservoir, spray head and line, a vent tube coupled to the spray head line and connected to the heated water reservoir, the illustration being significantly simplified in the interest of illustrating the general principals of the present disclosure;
[0009] FIG. 2 is an enlarged, partial fragmentary, cross-sectional view of the simplified diagrammatic illustration in FIG. 1 showing the relationship of the line, connection to an outlet of the reservoir, and connection to a feed line associated with a corresponding spray head, and the vent tube coupled to the line the relationships also showing a path for the passage of an accumulation of gas in the line; and
[0010] FIG. 3 is a view similar to that as shown in FIG. 2 illustrating some of the characteristics, conditions and relationships associated with a prior art line connecting a heated water reservoir to an associated spray head.
DETAILED DESCRIPTION
[0011] While the present disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and will be described herein in detail, one or more embodiments with the understanding that the present description is to be considered an exemplification of the principles of the disclosure and is not intended to be exhaustive or to limit the disclosure to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings.
[0012] With reference to FIG. 1 , a beverage making apparatus 20 is shown. The apparatus includes a heated water reservoir 22 containing a volume of water 24 . Water is introduced through a fill line 26 to a lower portion of the reservoir 22 . A heating device 28 introduces heat energy to the water thereby heating for use during beverage making cycles. A water level 32 is established in the reservoir 22 by a level sensor 36 . The level sensor detects the level of water in the reservoir and caused water to be added when the water level drops. A variety of level sensing devices may be provided in the form of conductivity detecting, acoustic, optical, or any other device or system for sensing a level of water in a reservoir. It is envisioned that the reference to the water level sensor is to be broadly interpreted.
[0013] The reservoir has an outlet port 40 through which heated water is dispense. A volume of water above the outlet port 42 defines the head for pressurizing the volume of water. The head pushes water out of the outlet port 40 under force of gravity. It should be noted that other forms of heated water dispensing devices may be provided that may not use a head 42 to drive water from the system. In this regard, the system could be driven by pressure of water introduced through the inlet line 26 or a combination of head and inlet line control. There is also envisioned that the reservoir may be pressurized such that a volume of air may be introduced into the reservoir to drive water from the reservoir in a controlled manner. With the foregoing in mind, it is envisioned that all forms of apparatus and processes for dispensing a volume of heated water from a heated water reservoir 22 should be considered and incorporated in this disclosure.
[0014] In the illustration of FIG. 1 , a spray head 50 or dispensing point is provided. The spray head is connected to the heated water reservoir by a line 52 extending there between.
[0015] The spray head and reservoir may be connected in a male-female coupling configuration.
[0016] In this regard, the line 52 may have ends 54 , 56 which extend over the corresponding spray head port 58 and outlet port 40 . While the coupling configuration may be reversed such that the ends of the line 54 , 56 may insert into the corresponding ports 58 , 40 , one configuration is shown in FIG. 1 . Additionally, the configuration with the line over the ports is shown in FIGS. 2 and 3 . One reason for this configuration is that this allows the ports 58 , 40 to be of rigid construction with the line 52 being of a flexible construction. In this regard, the ends 54 , 56 may be de-formably attached over the port 58 , 40 . The ends may be retained over the ports as a function of the flexibility of the line 52 material which may also include a clamp or other retaining device extending over the corresponding outside surface of the ends 54 , 56 to provide additional clamping force on the corresponding portions of the ports 58 , 40 .
[0017] Terms including beverage, beverage making, brewed, brewing, brewing substance, brewed liquid, and brewed beverage as may be used herein are intended to be broadly defined as including, but not limited to, the brewing or making of coffee, tea, herbs, other substances and any other form of beverages or food substances. This broad interpretation is also intended to include, but is not limited to any process of dispensing, infusing, steeping, reconstituting, diluting, dissolving, saturating or passing a liquid through or otherwise mixing or combining a beverage substance with a liquid such as water without limitation to the temperature of such liquid unless specified, and will benefit from or find application for the present disclosure. This broad interpretation is also intended to include, but is not limited to beverage substances such as ground coffee, tea, herbs, botonicals, liquid beverage concentrate, powdered beverage concentrate, flaked, granular, freeze dried or other forms of materials including liquid, gel, crystal or other forms of beverage or food materials to obtain a desired beverage or other food product.
[0018] With reference to FIG. 3 , prior art dispensing lines 52 a extend from a corresponding outlet port 40 and connect to a corresponding port 58 on the spray head. In the prior art, the orientation of the line 52 a is generally horizontal as having a slope of approximately zero (0). As a result of this orientation, and of the coupling of the line 52 a to the ports 40 , 58 a gap 65 is defined between the dimensional difference of the inside surface 67 of the port 40 and the inside surface 69 of the line 52 . The dimensional difference or gap 65 extending between the ports 40 , 58 define an area 71 in which gas may accumulate. The length of the line 52 combined with the horizontal orientation and the gap 65 result in an area which a significant volume may be occupied by gas. Some estimates suggest 30%-50% of the passage volume can be displaced by the gas, air bubbles. This equated to a significant reduction in the volume of water that can flow through the line 52 a . As a result, the volume of water flowing through the line might be significantly reduced. The volume might be significantly reduced because during some brewing cycles the bubble may be swept away, other cycles the bubble may be at its maximum, and further still other cycles' bubbles may be irregular with pockets of gas retained in the gap at different portions of the length of line 52 a . This unpredictability and inconsistency in the bubble volume creates significant variability in volume of water flowing through the line 52 a . This problem may be exacerbated in large volume brewers which use larger volumes of water to produce larger volumes of beverage.
[0019] Attempts to adjust for this variability have been somewhat unsuccessful. The attempts to adjust for the variability include calibrating the brewer or beverage maker so as to compensate for a maximum volume of gas which may occupy the gap 65 . However, the volume of gas is unpredictable and calibrating for a maximum volume may result in too much water flowing through when the bubble is absent or when different volumes of gas are retained in the line 52 a.
[0020] The variability arises depending on the flow rate, the surface tension of the water, the surface texture or characteristics of the line and corresponding line 52 a and corresponding ports 40 , 58 , the temperature, the mineral content of the water as well and any number of other factors. As a result of these numerous and somewhat unpredictable variables, it would be desirable to produce a beverage making device in which there might be additional consistency in the flow of water from the reservoir to the spray head. This interest is relevant in light of not only the variability of the size and volume of the gas bubble formed in the line 52 a , but also the variability of the water which might flow through such a process depending the geographic location, pressure, dissolved gases, as well as other characteristics of the water and setting in which the beverage maker is used.
[0021] With reference to FIG. 2 , a line 52 is disclosed which is attached to the ports 40 , 58 at ends 56 , 54 , respectively. The line 52 and associated reservoir 22 and spray head 50 have all the characteristics, functions and features as disclosed hereinabove. As can be seen in the enlarged view of FIG. 2 , the line 52 extends from the outlet port 40 of the reservoir 22 at an angle or slope 100 and connects to the port 58 at end 54 . The resulting slope allows evolved gas to flow with the water flow upwardly as gas is buoyant. As it travels from the outlet port 40 towards spray head port 58 the only dimensional mismatch involved the connection of the end 54 to the port 58 .
[0022] A vent tube 53 is coupled to the line 52 . The vent tube may have the same, smaller or greater diameter than the line 52 . As shown in FIGS. 1 and 2 , the vent tube 53 has an equal or slightly greater diameter while cross sectional area than the line 52 . This allows a volume of gas to evolve from the line 52 . A return line 55 couples to the vent tube 53 at one end and to the reservoir 22 at the other end. An outlet 57 of the passage 55 communicates with an upper portion 59 of the reservoir 22 . As such, the vent tube 53 , return line 55 and outlet 57 provide a path through which gas which evolves from the water flowing through the line 52 can return to the upper portion 59 of the reservoir. The gas or air bubbles carried in the water flowing through the line travel out of the fluid at the vent tube 53 and exit up and out through the return line 55 back to the upper portion or air gap 59 of the reservoir 22 .
[0023] Providing a greater path and opportunity for air to vent through and be returned to the system dramatically increases the consistency of flow through the line 52 .
[0024] Consistency of the volume of water delivered through the line 52 is important to providing consistent beverage flavor as well as brewed beverage volumes. As noted above, prior art systems may result in dramatic variability. By significantly reducing or eliminating variability in the water flow volume, beverage consistently can be greatly increased.
[0025] Positioning of the vent tube 53 may prove to be desirable along the upper portion of the sloped tube 52 . The gas flowing through the tube will tend to climb as it follows the uphill pass. The gas may evolve from the water flowing through the line 52 as a result of some what reduced pressure as it climbs the uphill slope. At the point where the tube transitions to the spray head gas can be removed. Alternatively, the vent tube 53 could be positioned any where along the line between the outlet of the reservoir up to the spray head. Positioning of the vent tube 53 closer to the spray head may provide benefits such that the head developed between the water level 32 and outlet tube 40 may have less of an effect on the vent tube 53 positioned away from and upwardly along the tube 52 . As an additional benefit, any steam or other condensation can be returned through the return line 55 . This configuration provides a closed loop system to maintain moisture, fluid, and air within the system.
[0026] Further, the dimensional difference is defined by a relatively small triangular section only at the top of the connection between the line 52 and port 58 . The dimensional difference between the potential air bubbles formed in the line 52 at a void 102 is nominal and insignificant compared to the potential bubble size that can be formed in the gap 65 as shown in FIG. 3 . In the disclosed line 52 as shown in FIGS. 1 and 2 , the gas bubble is generally consistent since gas flowing through the line 52 will replenish the void 102 as it passes through the line towards the spray head. As such the combination of the consistency and the nominal size tend to minimize or effectively remove any negative impact caused by gas in the line 52 . The nominal volume of air 104 allows the beverage maker to be calibrated accurately for a flow rate. This is because the variability in the bubble 104 size is so small it has little, if any impact on the flow rate through the line 52 .
[0027] While specific angular and proportional dimensions are not required, an example is provided by way of illustration and not limitation. It should be noted that the upward slope from the outlet port 40 to the spray head port 58 needs to be sufficiently angled to allow the gas to flow within the line. The angle must be greater than zero. Also, detailed refinement of the minimal angle can be achieved by understanding the effects of the interior surface material of the line 52 , and the accumulated mineral deposits which might ordinarily and customarily develop over time in such a line as well as characteristics of the water in which the beverage maker is installed. Once again, the beverage maker can be calibrated in its installed setting thereby accommodating some of these variables. The result will be that the disclosed line 52 disposed at an angle between the ports 40 , 58 will eliminate the variability in the water flow through the line.
[0028] It should be noted that this also impacts any bypass lines in which water is directed not to the spray head but to a line which introduces water at another portion of the beverage making process. For example, in a beverage brewing system some portion of water may be directed over the beverage making substance while another portion of water is directed to an outside portion of the funnel. As a result the streams are brought together to produce the final brewed beverage. The stream passing to a different portion of the funnel is known as a bypass stream. The teachings as described herein also apply to such a bypass line to help further reduce any inconsistencies in the bypass and increase the consistency of the resulting beverage.
[0029] With reference to FIG. 2 , the head 42 is shown to be approximately 3-¾ inches. The portion of water 106 above the spray head port 58 is approximately 2-¼ inches. The dimensional difference between the output 40 and the spray head port 58 is approximately 1-½ inches. This 1-½ inch vertical dimension is combined with a horizontal dimension of approximately 5 inches. The resulting positive slope or angle 100 between the port 40 , 58 facilitates movement of gas in the line 52 towards the spray head.
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Beverage making equipment, water heating equipment, and methods for using such equipment which use heated water and dispenses heated water from a heated water reservoir. The apparatus includes a water line extending from the heated water reservoir to a dispensing point, the line having a positive slope between the reservoir and dispensing point. A vent tube may also be used communicating with and coupled to the line with a return passage communicating with the vent and reservoir. The method of dispensing water from a heated water reservoir involves dispensing water from the reservoir at one level and delivering water to a dispensing point at a second level positioned at a positive dimension above the dispensing port of the heated water reservoir. the method may also include providing a vent tube coupled to and communicating with the line for removing gas which evolves from water passing through the line and returning the gas to the reservoir.
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This is a continuation of application Ser. No. 07/656,182, filed as PCT/US90/06628, Nov. 13, 1990, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to the general field of regulation of the growth and repair of tubular, or luminal, structures.
Tubular structures within the body (including bronchi of the lung, the entire gastrointestinal tract from the esophagus to the anus, the ureters and urethra of the genitourinary system, the fallopian tubes and vas deferens of the reproductive system, and the blood vessels) are all subject to luminal constriction and obstruction to flow. As a result, tissues and organs downstream of the obstruction are deprived of vital elements and tissues and organs upstream are dammed up with fluid and/or toxic products.
Surgical repair is often indicated in an attempt to relieve these obstructions. However, the repair may be unsuccessful or short-lived due to accelerated obstruction and a recurrence of the events that led to the initial crisis. Overproliferation of smooth muscle cells (SMC) as part of the natural repair process may contribute to luminal occlusion. In the arterial system, for example, restenosis rates of 25 to 35% have been noted within three months following percutaneous balloon angioplasty, and current estimates of the life expectancy of saphenous venin bypass grafts do not exceed 7 years. In the gastrointestinal system, this same phenomenon presents as recurrent bowel obstruction after lysis of adhesions or surgical anastomotic repair, and in the reproductive system as an ineffective surgical repair of the fallopian tubes or vas deferens.
There have been various attempts to limit occlusion. For example, for blood vessels, effort has been directed at various circulating (intravenous) factors such as heparin. Such factors inhibit or stimulate the clotting process and may also affect smooth muscle cell proliferation. Attempt have also been made to control environmental factors such as blood pressure, cholesterol, or smoking (nicotine). As regards lungs, attempts to limit occlusion have been directed at aerosolized factors and modulators of vascular tone (e.g., bronchodialators) and control of mucous formation. Efforts concerning the genitourinary system have focused on maintaining adequate flow, e.g. by controlling pH to enhance the solubility of stone material or by mechanical means such as ultrasound energy to break-up stones or uretal stents.
SUMMARY OF THE INVENTION
In general, one aspect of the invention features a method of regulating repair following injury to luminal tissue that includes administering a modulator of cell or tissue growth at an extraluminal site adjacent the injured tissue. "Regulating repair" is meant to include controlling luminal occlusion (e.g., the reduction or the prevention of formation of such occlusion). By luminal tissue is meant the tissue, primarily endothelium, in the lumen of a tubular structure. A modulator is an agent that effects a change in the rate of cell or tissue growth. An extraluminal site is one located outside and adjacent to the injured tubular structure, one example being the adventitia, the layer of loose connective tissue forming the outermost coating of an organ.
Preferred embodiments of the invention include the following features. The invention is particularly appropriate for controlling repair of the vascular system, preferably repair of an artery, and the preferred modulating agent is either anticoagulant or non-anticoagulant heparin. The modulator preferably is delivered to the adventitia adjacent the artery in a polymer matrix (e.g., an ethylene-vinyl acetate copolymer), at a rate of from 1 μg to 100 mg/day, for a period of at least 24 hours. Other sites of injury for which the method is particularly appropriate include the fallopian tubes or the vas deferens of the reproductive system, the ureter or the prostate gland of the genitourinary system, the bowel of the gastrointestinal system, or the trachia or the bronchial tree of the pulmonary system. Other vehicles for administration include aqueous gels, foams, or sprays (e.g. aerosolized).
In another aspect, the invention generally features a method of testing the effectiveness of a modulator in regulating repair following injury to luminal tissue that includes administering the modulator to an extraluminal site adjacent the tissue and determining the extent of regulation of repair following such administration.
Local administration of a modulating agent to an extraluminal site adjacent an injured luminal structure or organ allows for orderly repair of the injured endothelium while reducing detrimental side effects of other forms of administration.
Another aspect of the invention features a controlled release polymer device that includes a capillary action release optimizing element that may also serve to immobilize the device at a local site, e.g. to the outside of a lumen. The device comprises a controlled release polymer matrix (such as one described above) loaded with a drug, e.g., a cell-growth modulating agent according to the invention. The device is configured as a solid encasing a portion of the release optimizing element, which is configured as an elongated fibrous suture and preferrably is made from a material that supports capillary action and is suitable for immobilizing the polymer body. The release optimizing element may take the form of a suture (made from standard suturing materials) which itself is not impregnated with drug. Preferably, the outer solid surfaces are coated to retard release of the modulator from coated surfaces. Also preferably, the polymer is shaped as a torroidal structure or a disc with a generally central opening (preferably the opening is a hole extending completely through the polymer body) containing the release element. This aspect of the invention is particularly adapted to matricies that provide diffusion controlled release. This aspect of the invention provides various advantages. The element is firmly anchored. The wicking effect of the element increases efficiency by reducing the total amount of drug residing in the matrix when release effectively ends. The kinetics of release (rate of release over time) is more stable.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiment thereof, and from the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The method of the invention permits local administration of a modulator of cell or tissue growth to the outside of a tubular (or luminal) physiological structure for the purpose of regulating the repair of that structure following injury, for example, by surgical procedures. Examples of systems containing such structures and typical surgical procedures where regulating the repair process would be valuable are the vascular system (e.g., vascular anastomses that accompany procedures such as organ transplant, coronary by-pass surgery, systemic arterio-arterio and arterio-venus bypass surgery, and arterio-venus shunts that accompany vascular access for dialysis); the reproductive system (reversal of tubal ligation or vasectomy); genitourinary system (prostate surgery); gastrointestinal system (anastomotic repair of a bowel obstruction); and the pulmonary system (repair or reconstruction of traumatic or surgical injury to trachial or bronchial structures).
A wide range of growth modulating agents are appropriate for use in carrying out the method of the invention including those indicated as affecting angiogenesis, smooth muscle cell proliferation or vascularization. Some examples (as described in more detail below) include: heparin; the angiotensin converting enzyme inhibitors (e.g., captopril); angiotensin; angiogenic growth factors; heparin binding growth factors (See U.S. Pat. No. 4,882,275), particularly fibroblast growth factor; platelet derived growth factor (PDGF); transforming growth factor-β (TGF-β); immunosupressants (e.g., cyclosporine); calcium channel inhibitors (e.g., nifedipine); as well as cytokines and interleukins which control cell-cell interaction during vascular or other luminal tissue repair in response to injury.
The modulator may be delivered to the appropriate site outside the tubular structure of interest in a delivery system, e.g., a matrix composed of the modulator in solid form and a polymer, such as an ethylene-vinyl acetate copolymer (described in detail below). The polymer matrix delivery system can be made from any generally inert biocompatible polymer material. The material can be formed in a matrix as described below, or it can be in capsule form or other known controlled release configurations. Desired kinetics for the release of a particular drug can be achieved by known techniques by controlling the matrix fabrication techniques or the nature of the polymer of the delivery system.
A polymer matrix system to deliver the modulating agent is particularly useful when the substance to be delivered is unstable in solution, rapidly degraded, prone to precipitation, or of limited solubility. Alternate delivery systems which may be especially appropriate for modulating agents include bioerodible systems such as polyorthoester systems described in Sparer et al., J. Controlled Release 1:23-32 (1984); poly (glycolide-CO-DL-lactide) microcapsules disclosed in Lawter et al., Proc. Int'l. Symp. Control. Rel. Bioact. Mater. 14:99-100 (1987); and poly (organophosphazene) bound drugs as disclosed by Neenan and Allcock, Biomaterials 3: 78-80 (1982), and Grolleman et al., J. of Controlled Release 3: 143-154 (1986).
A particularly preferred polymer release matrix is the ethylene-vinyl acetate copolymer (EVAc) matrix described in Folkman and Langer U.S. Pat. No. 4,391,797, hereby incorporated by reference.
A particularly preferred cell and tissue growth modulating agent is heparin, an α,β-glucosidically linked, highly sulfated copolymer of uronic acid and glucosamine. Preparations are polydisperse with a molecular weight range of from 5,000-40,000 daltons. The precise composition of commercial heparin and the precise degree of antiproliferative activity vary depending on the source and method of purification. By the term "heparin," we mean to include all forms of heparin and all fragments of heparin having an antiproliferative effect, e.g., both anticoagulant heparin and non-anticoagulant heparin (e.g., heparin that is identified by its failure to bind to an anti-thrombin III affinity column) have antiproliferative activity. Other well known methods of preparing non-anticoagulent heparin include modification of native heparin by periodate oxidation or by enzymatic degradation, and de novo synthesis.
To establish loading of a matrix, drug release in vivo from the matrix (e.g. an EVAc matrix) is assumed to mirror release in vitro (Brown et al., J. Pharm. Sci. 72:1181-1185 (1983)). The maximum number of units of modulator to be applied directly to the extraluminal tissue (e.g., an arterial wall) can be estimated by using in vitro release data. Animal models such as those described below provide a dose response curve. To scale up from animal to human delivery, e.g., in human arteries, one considers only the difference in luminal diameter (e.g., scaling up from rat to human vessel diameter involves a factor of approximately four to ten-fold). Because achieving systemic effects is not desired, body weight does not enter into the calculation.
At the time of surgical intervention of a typical surgical procedure, the polymer matrix embedded with the modulator is placed at an extraluminal site (e.g., in the adventitia) adjacent the injured lumen (e.g., artery) and the adjacent muscles and facia are sutured closed to insure immobilization of the matrix. During recovery of the patient, fluid is absorbed by the matrix and solubilizes the modulator, which then diffuses in solution through the channels of the matrix and out into the adventitia. Positioning of the matrix in the adventitia assures that heparin delivery takes place at the exterior surface of the blood vessel wall, at the site of injury.
The following examples of specific procedures, modulators and delivery systems used in animal models are provided to illustrate and not to limit the invention.
EXAMPLE 1
Heparin, particularly non-anticoagulent heparin, can be administered to an artery from an EVAc slow release matrix according to the following example.
An EVAc matrix loaded with 0.1-1000 mg (most preferably 0.5-500 mg) non-anticoagulent heparin is prepared as described below. As part of the surgical procedure, (e.g. coronary by-pass or coronary valve replacement) the matrix is sutured in the adventitia adjacent the artery. The adjacent muscles and facia are sutured closed to immobilize the matrix adjacent the arterial repair. The heparin is released at a rate of 1 μg-100 mg/day, for more than one (preferably more than three, and most preferably more than seven) days.
EXAMPLE 2
Anti-coagulant (AC) heparin (Choay Heparin 1453, m.w. 12,000-18,000 dalton, U.S.P. 160 U/mg, in vitro antiproliferative activity 80% (as described by Castellot et al. (1987) Seminars in Thrombosis and Hemostasis 13:489-503) or non-anti-coagulant (NAC) heparin (Choay heparin 1772, m.w. 5000-8000 dalton, U.S.P. 10 U/mg, in vitro antiproliferative activity 80%), Choay Institute, Paris, France, were embedded in polymer matrices using a solvent casting technique as described in Langer et al., Methods in Enzymol. 112:399-423 (1985). First, ethylene-vinyl acetate copolymer (ELVAX-40P, 40% vinyl acetate, E. I. DuPont, Wilm., Del. or U.S.I. of Cincinnati, Ohio) was dissolved in methylene chloride to a concentration of 10% (w/v). Dry powdered heparin was then sieved to particle sizes less than 180 microns and added to the EVAc solution. If the heparin aggregated, the drug was dissolved in normal saline, lyophylized to a powder, pulverized with mortar and pestle in a humidity controlled box and then sieved and added to the dissolved EVAc. The drug-polymer suspension was vortexed, let stand for 15 seconds to allow air bubbles to settle out and then poured into glass molds that had been precooled on dry ice. At these temperatures, the heparin was immediately frozen in place so as to be uniformly distributed through the matrix and not settle on the bottom. The resultant matrix was a homogeneous dispersion of heparin within EVAc. Once hardened, the matrices were removed from their glass molds, placed in a -20° C. freezer for two days and then under vacuum (600 mtorr) for another two days.
For use, smaller pellets were cut from the larger slabs to specific sizes and weights, and a coating was applied by placing a 20 gauge intravenous needle one cm into the center of the face of the matrix pellet and then immersing the pellet in a solution of 10% EVAc dissolved in methylene chloride for 5 seconds. As the pellets were withdrawn from the solution, they were spun slowly for a minute to allow for uniform coating. This entire process was repeated twice more. The matrices were left on the needles and placed in a chemical fume hood to allow for further solvent evaporation. After 12 hours, the extraneous polymer material that had migrated up the needle was removed by spinning a tweezers around the base of the needle as it was withdrawn from the matrix pellets. This insured that the extra polymer material did not collapse over the hole and that the hole remained open. Matrices were stored in a dessicator where solvent evaporation continued to completion.
Male Sprague-Dawley rats (300-500 gm, Charles River Breeding Laboratories, Wilmington, Mass.) were anesthetized with sodium nembutol 0.5 mg/gm body weight, and supplemental anesthesia was maintained with ether inhalation. A midline incision was made from the mandible to the mid-sternum. The carotid artery was exposed along the length of the bifurcation with blunt dissection, and the external carotid artery was isolated and ligated in its cephalad portion. A 2 French Fogarty balloon catheter (American Edwards Laboratories, Santa Ana, Calif.) was introduced into the arteriotomy of the external carotid artery and passed in its inflated state over the endothelium of the common carotid artery three times. The catheter was then deflated and removed from the external carotid artery, which was then ligated. In different groups of animals, EVAc matrices containing no drug, AC heparin or NAC heparin were placed adjacent to the injured artery. The adjacent muscles and fascia were sutured closed with 4-0 nylon suture to insure immobilization of the pellet. The midline incision was closed with the same suture and animals observed in separate cages during recovery. As a control, to demonstrate that the effect at issue is specific for adventitial or extraluminal delivery, EVAc matricies were placed in a subcutaneous pocket over the animal's dorsal neck region. In other animals, an osmotic infusion pump (ALZA Corporation, Palo Alto, Calif.) provided continuous iv administration of these same agents. The pumpφ5X was placed in a pocket made in the neck of the rat, and a silastic catheter extended from the pump to the right internal jugular vein. AC and NAC heparins were mixed in lactated Ringer's solution and delivered at 0.3 mg per kilogram of body weight per hour. Control animals received lactated Ringer's infusion. The overall doses of the drugs administered are displayed in Table I.
TABLE I______________________________________HEPARIN DOSAGE mg (over 14 days) MATRICESINTRAVENOUS CAROTID DORSAL______________________________________NAC (5) 25.9-43.3* (10) 19.5 ± 1.9 (5) 18.5 ± 2.9AC (5) 25.9-43.3* (8) 8.1 ± 1.9 (4) 7.1 ± 0.2______________________________________ *set to 0.3 mg/kg/hr and dictated by the size of the animal numbers in parentheses represent the number of animals in each group
As an indication of anti-coagulation activity, activated partial thromboplastin times (aPTT) were determined within the first 24-36 hours after the procedure and at day 14. To observe the percent of luminal occlusion, animals were euthanized while undergoing intravascular fixation perfusion using methods described in A. W. Clowes et al., Lab, Invest. 49:327 et seq. (1983). Photomicrographs of all arterial sections were obtained, and the percent of luminal occlusion was calculated for each arterial segment using computerized digital planimetry. Specifically, the natural lumen boundary is apparent by photomicroscopy. The boundary is extended inwardly by inclusions. Digital planimetry is used to provide a measure of the cross-sectional area of the natural lumen boundary, divided into the area of the inclusion, yielding percent occlusion.
Anti-coagulation activity as given by the aPTT (Table II) and extent of luminal occlusion (Table III), for each animal group, are detailed below.
TABLE II______________________________________aPTT (sec) MATRICES INTRAVENOUS CAROTID DORSAL______________________________________CONTROL (6) 16.2 ± 0.1 (8) 16.5 ± 0.4NAC (5) 18.4 ± 0.6 (10) 15.0 ± 0.4 (5) 17.5 ± 0.5AC (5) 40.0 ± 11.8* (8) 15.3 ± 0.1 (4) 17.0 ± 1.0______________________________________ numbers in parentheses represent the number of animals in each group statistical significance compared with corresponding controls: *p<0.0005
TABLE III______________________________________LUMINAL OCCLUSION (%) INTRA- MATRICES VENOUS CAROTID DORSAL______________________________________CONTROL (6) 52.2 ± 4.2 (8) 55.9 ± 4.3NAC (5) 46.4 ± 3.9 (10) 17.7 ± 3.78@ (5) 45.0 ± 2.0AC (5) 16.8 ± 4.3** (8) 9.4 ± 2.6* (4) 28.0 ± 2.6______________________________________ numbers in parentheses represent the number of animals in each group statistical significance compared with corresponding controls: *p<0.0005, **p<0.0003, @ p<0.0001
Referring to Table II, only the intravenous administration of AC heparin produced systemic anticoagulation. Neither the local matrix delivery of either heparin, in subcutaneous or adventitial positions, nor the intravenous infusion of NAC heparin had any discernable effect on clotting function. None of the animals in any groups suffered from excessive bleeding. Referring to Table III, intravenous AC heparin infusion reduced luminal occlusion 68%, from a control value of 52.2 to 16.8%. NAC heparin delivered in the same fashion achieved only an 11% reduction (no statistical difference in comparison to control). Subcutaneous matrix delivery of NAC heparin also showed no significant difference in luminal occlusion, but similar delivery of AC heparin reduced occlusion by 52%. The largest effect on luminal occlusion was observed with adventitial delivery. Occlusion was reduced from 55.9% to 9.4% (83% reduction) in animals with AC heparin matrices, and to 17.7% (68% reduction) in animals with NAC heparin matrices.
EXAMPLE 3
To generate a dose response curve for NAC heparin, twelve rats were implated with NAC heparin-bearing matrices of different net weights so as to deliver different dosages of heparin over the 14 day period. As the dose of the NAC heparin was increased, the effect on SMC proliferation rose, such that at the highest dose tested, NAC heparin inhibited SMC proliferation to an equal extent as AC heparin, at five times the equivalent dose. A dose response experiment was not performed for AC heparin as the amount of heparin delivered in the uniform dose study was already low and had achieved over 80% inhibition of SMC proliferation.
At a rate of about 0.8 mg/day for in vitro release, the maximum amount of heparin human arteries would be exposed to would be no higher than 20-50 units/hour, and systemic levels would be undetectable. This is in marked contrast to the 1000-1500 units/hour of i.v. infusion currently used in clinical practice for systemic anticoagulation.
The local, extraluminal action of the least potent of this class of agents, captopril, was studied in the balloon injury/polymer matrix/adventitial delivery model described above. Powdered captopril (Capoten, Squibb Pharmaceuticals) was embedded within EVAc matrices at 50% loading and delivered at a dosage of 10.79±0.1 mg, over the course of 14 days, to the adventitia of the carotid artery. The percent of luminal occlusion was 37.7±3.0.
EXAMPLE 5
Angiotensin II (AII) has been demonstrated to have both inhibitory and stimulatory effects on SMCs in tissue culture and has also been demonstrated to induce blood vessel growth in avascular structures such as the the rabbit cornea, independent of its hemodynamic effects. Matrices of ethylene-vinyl acetate copolymer were embedded with AII and sustained first order release demonstrated for more than one month. As the drug is potent in ng quantities, the EVAc matrix drug embedding technique was modified to include bovine serum albumin (BSA) as a carrier compound. When dry powdered AII was mixed with dry powdered BSA in a 1 to 500 ratio and then embedded within a EVAc matrix, the rate of BSA release dictated the rate of AII release. When this system was then placed in the balloon injury model described above, the vascular occlusion was noted and the number of blood vessels surrounding the implant counted and compared to control.
DOSE: 17 μg over the course of 14 days
LUMINAL OCCLUSION: 22.5-64%
INHIBITION COMPARED TO CONTROL: 0-62.6%
NUMBER OF VESSELS SURROUNDING AII IMPLANT: 27
NUMBER OF VESSELS SURROUNDING CONTROL IMPLANT: 6
Angiotensin II was able to induce a marked vascular response regardless of its ability to control SMC proliferation.
EXAMPLE 6
Heparin binding growth factors such as fibroblast growth factor (FGF) in culture are mitogens for a number of cell types and a potent angiogenesis factor in vivo that has no apparent effect on blood pressure. As growth factor activity may be lost if the factor is embedded in standard controlled release devices, an alternative method was used, taking of advantage the inherent ability of such growth factors to adhere to heparin.
FGF (Takeda Industries, Japan) was bound to heparin sepharose beads to stabilize the factor and to provide a solid carrier for minute quantities of the liquid growth factor. Aliquots of FGF were mixed with 2 ml of I 125 FGF (1.2 mg/ml) and then incubated for 1 hour with the heparin sepharose beads. Subsequent release of FGF from the beads was followed in 0.15M NaCl buffer. Microspheres containing FGF were constructed by dropping a mixture of sodium alginate (1%) with heparin sepharose bead-bound FGF through a glass Pasteur pipette into a hardening solution of calcium chloride (1.5 weight %). Release kinetics were determined for microcapsules containing 6 ml of FGF and 2 ml of I 125 FGF bound to 125 mg of the heparin sepharose beads in 500 ml of 0.15M NaCl. Heparin sepharose bead-laden FGF was incorporated within alginate microcapsules with 74% efficiency, and release of the FGF over time was retarded and prolonged in comparison to release from the unencapsulated beads. Bioactivity was retained by 87.6±12% of the factor preparation. Microspheres prepared as above were placed adjacent to noninjured and balloon endothelialized carotid arteries. In both blood vessels a significant increase in local vascularity was noted.
In addition to the examples described above, the method can be used in a laboratory setting to test the luminal repair-enhancing effect of a variety of potentially potent cell or tissue growth modulators previously discarded as ineffective because they do not act systemically, do not act in a similar fashion over a range of dosages, are degraded before they achieve their effects if applied systemically, or have side effects when delivered systemically.
A BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a highly diagrammatic representation of a torroidal structure (FIG. 1A) and (FIG. 1B) a disc according to the invention comprising a diffusion-controlled-release polymer body containing a drug. The polymer body 10 contains a centrally located hole through which suture 12 is threaded. The polymer body 10 has an outer coating 14 (e.g. if the polymer is a drug-loaded EVA matrix as described in U.S. Pat. No. 4,391,797, unloaded polymer can be used for the coating.
Other embodiments are within the following claims.
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A method of regulating repair in a physiological system following injury to the lumen of a tubular structure in that system, and of testing the effectiveness of regulatory agent, is presented. The method includes administering a modulator of cell or tissue growth to an extraluminal site adjacent the injured tissue.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to the flow of fluid through tubes, including the treatment of the interior of tubes.
[0002] Many types of equipment employ tubes or tube bundles. It is often necessary to introduce a fluid into the tubes and to remove fluid from the tubes, for a variety of purposes. For example, it is often necessary to treat the interior of these tubes. In many instances, foreign matter builds up on the inner surfaces of the tubes, which degrades performance of the equipment, and must be cleaned to remove the foreign matter.
[0003] For example, heat exchangers and other types of condensers, particularly those used in the production of electrical power, develop scale on the interior surfaces of the condenser tubes. This scale impedes heat transfer between the interior of the tubes and the fluid (for example, water or steam) surrounding the tubes, and reduces the efficiency of the power generator. The term “fluid” is used herein to include both gases and liquids. In a typical condenser, for example, the tube bundle is contained with an enclosed condenser box, which affords limited access to the tube bundle. Cleaning the interior walls of the tubes is a challenge, given the difficult access to the interior of the tubes, and the need to accomplish the cleaning as quickly as possible to minimize the down time of the generator.
[0004] The current technology employed to clean the interior surfaces of tubes falls broadly into one of three categories: mechanical tube cleaning, hydro-blasting, and chemical cleaning. Each technique is very well known to those in the industry.
[0005] Mechanical tube cleaning is generally the fastest method for cleaning deposits from the interior surfaces of tubes. There are numerous types of mechanical tube cleaners, the design of which are based on the type of deposit the device will be removing. Mechanical tube cleaning devices can be used to remove very soft to very hard deposits. Examples of hard deposits are calcium, mostly calcium carbonate, manganese, and silica-based deposits. Mechanical tube cleaning involves propelling a tube cleaner, also known as a scraper, through the tube using a fluid under pressure. As water propels the tube cleaner, deposit is removed by the contact points of the device and then remaining deposit is subsequently flushed out by the water. Mechanical cleaning is generally the most common method because it is fast, cost effective, and the more durable tube cleaning devices are able to remove most deposits. The major disadvantage of this method is that some deposits are so difficult that mechanical cleaning is either not effective or less cost effective than other techniques. For example, a very thick calcium carbonate deposit would be very hard to remove with a mechanical tube cleaner. With such a deposit, it is likely necessary to make multiple passes through the tube with different sized scrapers. The process would begin with a smaller diameter scraper, with subsequent passes being made by scrapers with increasingly larger diameters to progressively scrape layers of scale from the inner tube surface. Depending on the size of the deposit, the mechanical process could be impractical in this case.
[0006] Hydro-blasting uses extremely high pressured water to remove deposit from the inner walls of tubes. An operator uses a lance that shoots out high pressured water and manually feeds this lance down each tube. This method can be seen as a substitute to mechanical tube cleaning, but has some significant disadvantages. Generally hydro-blasting takes more time than mechanical tube cleaning and the high pressured water can make this method extremely unsafe for the lance operator.
[0007] Chemical cleaning is preferable on small tube bundles (fewer than about 3,000 tubes of average length, typically between 20 to 50 feet in length), or when larger tube bundles have very serious deposits. Broadly, chemical cleaning involves flushing chemicals through the tubes. The chemical comes into contact with scale, and dissolves it. Typically, the entire condenser tube bundle is filled with the chemical. This system uses a re-circulating pump system that includes an inlet hose that forces the chemical from a reservoir into the bundle, and an outlet hose that evacuates the chemical and returns it to the reservoir. The chemical is re-circulated from the reservoir by the pump until the cleaning operation has been completed. New chemical is supplied to the bundle from a separate reservoir either automatically by a pump or manually. Some systems include a pH gauge that monitors the changing pH of the chemical during the cleaning operation. As the chemical dissolves the deposit, the pH of the chemical changes, typically increasing. When the pH of the chemical rises to a predetermined level, another pump begins supplying chemical from a separate reservoir. Also typically, the predetermined pH level of the system can be set within a range. While this system is effective in removing deposits from the tubes, it is expensive primarily due to the cost of the chemical required to completely fill the tube bundle.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention provides a device for providing fluid access to the interior of a tube, and a system, method and device for circulating fluid through tubes. The system can be used for treating the interior surface of one or more tubes, and utilizes a sealing device of the type provided by the present invention that seals the ends of the tube while permitting the fluid to enter and exit the tube. The system can be used to force a chemical liquid through the tube to remove scale from the interior surfaces of the tube. The system can be used to treat individual tubes or multiple tubes. Entire sections of a tube bundle can be treated. The system provided by the present invention is particularly useful for cleaning scale from the interior of tubes, like those in the tube bundle of a condenser or heat exchanger, using a chemical cleaning fluid. The sealing device can be used to introduce fluid into a tube, and allow for removal of the fluid from the interior of a tube for any purpose, including cleaning or descaling the interior surface walls of the tube.
[0009] The sealing device provided by the present invention includes an inlet for receiving fluid, an outlet, a fluid passage adapted to permit flow of the fluid between the inlet and the outlet, and a seal adapted to prevent flow of the fluid between the sealing device and the interior of the tube. A first sealing device may be mounted within a first end of a tube and a second sealing device may be mounted within a second end of the tube to permit the fluid to pass through the tube. In a preferred embodiment of the invention, the sealing device provides a seal between the device and the tube wall utilizing a sealing material that can be expanded under pressure to force the sealing material against the interior surface of the tube to provide a seal against fluid leaking from the tube, and against foreign matter entering the tube from the exterior of the tube. Preferably, the sealing material is expanded against the inner surface of the tube using a nut and bolt assembly provided with the sealing device that compresses the sealing material. Also preferably, the sealing material is at least one sealing sleeve. In most applications, two sealing sleeves are preferred.
[0010] A treatment system provided by the present invention is used to treat the interior surfaces of at least one tube with a treatment fluid. The treatment system can be used to remove scale from the inner surfaces of tubes by forcing a chemical through the tube.
[0011] The system includes a supply of treatment fluid, a feed that provides treatment fluid from the supply to the tube, a return that recirculates treatment fluid to the supply after it has passed through the tube, and a sealing device of the type provided by the present invention. The sealing device establishes fluid communication between the supply and the interior of the tube. The device includes an inlet and an outlet, a fluid passage adapted to permit flow of the treatment fluid between the inlet and the outlet, and a seal adapted to prevent flow of the fluid between the device and the interior of the tube, and to prevent foreign matter from entering the tube from the exterior of the tube.
[0012] The treatment system can be used to isolate a section comprising multiple tubes to clean more than one tube of the tube bundle while bypassing sections that do not need to be cleaned. In this instance, a sealing device is mounted in the inlet and outlet ends of the tubes being cleaned, and manifolds are provided that are in fluid communication with the inlets and outlets of the tubes being cleaned. As is known in the art, the manifolds distribute the treatment fluid to and from the tubes being treated.
[0013] The system provided by the present invention can be configured in a number of ways to treat a section comprising multiple tubes. For example, a section of six tubes can be treated by configuring the system in a “multiple loop” configuration. In a multiple loop configuration, pairs of tubes are coupled to allow treatment fluid to enter a first tube of the pair, exit the first tube and enter the second tube. The fluid is returned to the system upon exiting the second tube. In this configuration, the system defines three independent flow loops. Alternately, a system can be provided that employs a “continuous loop” configuration. In a continuous loop configuration, the tubes are coupled to form a single flow path for the treatment fluid. The outlets and inlets of the tubes are coupled to form the flow path. With the “multiple loop” and the “continuous loop” configurations, the pump and fluid treatment reservoir could be completely contained within the condenser box. In that case, all hoses that are used to connect the tubes with the pumping system are also located within the condenser box.
[0014] The system also can employ an “individual loop” configuration. In an individual loop configuration, each tube forms an independent flow path to and from the system supply. In an individual loop configuration, the inlet of each tube receives treatment fluid from the supply through a single inlet, and returns fluid to the supply through a single outlet. This configuration includes a hose that runs from the pumping system to an inlet manifold that distributes the treatment fluid to the inlet of each tube, and an outlet manifold on the outlet side of the of the tube bundle that collects the treatment fluid after it passes through and exits the tubes, and returns it to the pumping system.
[0015] Other configurations, including combinations of these configurations, can be employed.
[0016] The method provided by the present invention includes the steps of providing a supply of treatment fluid, feeding treatment fluid from the supply to the tube, returning treatment fluid to the supply after it has passed through the tube, and providing fluid access to the interior of the tubes using a device that includes an inlet and an outlet, a fluid passage adapted to permit flow of the treatment fluid between the inlet and outlet, and a seal adapted to prevent flow of the fluid between said device and the exterior of the tube.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0017] The following detailed description of the preferred embodiments may be understood better if reference is made to the appended drawing, in which:
[0018] FIG. 1 is a graphic depiction of a tube bundle, of the type used in condensers;
[0019] FIG. 2 is a side view of the bundle shown in FIG. 1 , depicting either the inlet or outlet of the tube bundle;
[0020] FIG. 3 is a graphic representation showing a system provided by the present invention installed to clean part of a tube bundle of the type shown in FIGS. 1 and 2 ;
[0021] FIG. 4 is a graphic representation showing a system provided by the present invention installed to clean a pair of tubes of the bundle shown in FIGS. 1 and 2 ;
[0022] FIG. 5 shows a system provided by the present invention for treating a section of six tubes of the bundle shown in FIGS. 1 and 2 , in a multiple loop configuration;
[0023] FIG. 6 is a side view of the equipment shown in FIG. 5
[0024] FIG. 7 is a side sectional view of a sealing plug provided by the present invention;
[0025] FIG. 8 is a side section view of the sealing plug shown in FIG. 7 mounted to a tube, with an endpiece mounted to the sealing plug, and a coupling and hose mounted to the endpiece;
[0026] FIG. 9 shows a system provided by the present invention for treating a section of six tubes of the bundle shown in FIGS. 1 and 2 , in an individual loop configuration;
[0027] FIG. 10 is a side view of the equipment shown in FIG. 9 ;
[0028] FIG. 11 shows a system provided by the present invention for treating a section of six tubes of the bundle shown in FIGS. 1 and 2 , in a continuous loop configuration;
[0029] FIG. 12 is a side view of the equipment shown in FIG. 11 ;
[0030] FIG. 13 is an exploded view of the sealing plug shown in FIG. 7 ; and
[0031] FIG. 14 is a perspective view of the sealing plug shown in FIG. 13 .
DETAILED DESCRIPTION OF EMBODIMENTS
[0032] The preferred embodiments of the present invention shown in the drawing are particularly useful for chemically cleaning scale from the inner surfaces of condenser and heat exchanger tubes. However, the present invention can be used to deliver any type of fluid to the interior of tubes for any purpose. Further, the present invention, including the embodiments shown in the drawing, can be used to treat tubes singly or together in a section of a tube bundle.
[0033] When used as a chemical cleaning system to, for example, clean the interior of condenser tubes, the system can employ any type of chemical cleaning fluid currently used to clean scale and deposits from the inner surfaces of condenser tubes. Chemical cleaning of condenser tubing is a well-known and established industry, and the chemicals that can be used in the cleaning process are very well known. For example, the chemical sold for this purpose by Apex Engineering Products Corporation, of Aurora, Ill., (“Apex”) under the trademark RYDLYME® works well and can be used with the present invention. Similarly, the manifolds, fluid supply reservoirs, pH sensors, control circuits and pumps used in current chemical cleaning systems are well known. Examples are the pumping system components sold by Apex and Goodway Technologies Corporation of Stamford, Conn. Consequently, those components of the system will not be described in detail herein.
[0034] FIGS. 1 and 2 are graphic representations of a tube bundle 1 of a condenser that can be cleaned by the preferred embodiments described herein. Tube bundle 1 is composed of a number of individual tubes 2 . During use of the condenser, as is well known, the interior surfaces of tubes 2 become coated with a scale or deposits. The scale degrades the heat transfer capabilities of tubes 2 , and must be removed. FIGS. 3 and 4 show a system 10 provided by the present invention that can be used to remove the scale, as well as other foreign material, from the inner surfaces of tubes 2 .
[0035] System 10 includes a reservoir 12 that contains a chemical, of any known type, that removes scale from condenser tubes. A feed 14 , consisting of an inlet line of any known desirable type, is provided to deliver chemical fluid from reservoir 12 to tube bundle 16 . FIGS. 3 and 4 show system 10 configured to clean a pair of adjacent tubes 18 a and 18 b. Four sealing plugs 20 are used to seal the ends of tubes 18 and permit the passage of cleaning fluid to and from tubes 18 a and 18 b. A U-connector 22 is provided between two of sealing plugs 20 to allow cleaning fluid to flow from the first tube 18 a to the second tube 18 b. Return 24 is installed between the sealing plug 20 that seals the outlet of tube 18 b and reservoir 12 to permit the cleaning fluid to be recycled to reservoir 12 after it has made a pass through tubes 18 a and 18 b. A pump 28 is employed to circulate chemical cleaning fluid from reservoir 12 throughout system 10 . A pH sensor 26 can be provided to measure the pH of the cleaning fluid as it is reused. As the cleaning fluid is recycled through system 10 , its pH rises as it reacts with the scale within tubes 18 a and 18 b. As the pH of the cleaning fluid rises, it becomes less effective to react with and dissolve the scale within tubes 18 a and 18 b. Sensor 26 can be set to provide an indication that a predetermined pH level has been reached, at which point a fresh supply of cleaning fluid can be provided from reservoir 13 to system 10 , either manually by dumping new chemical into reservoir 12 or automatically by having the pH gauge trigger pump 29 to pump new chemical into reservoir 12 .
[0036] In use, pump 28 forces cleaning fluid from reservoir 12 into feed 14 and into tube 18 a via a sealing plug 20 . As the cleaning fluid flows through tube 18 a, it reacts with scale on the inner surface of tube 18 a, dissolving at least some of it. The fluid exits tube 18 a through another sealing plug 20 , passes through U-connector 22 , and enters tube 18 b through a third sealing plug 20 . As with tube 18 a, the cleaning fluid reacts with scale on the inner surface of tube 18 b as it flows through it, dissolving some of the scale as it does so. The cleaning fluid exits tube 18 b through a fourth sealing plug 20 , enters return 24 and is pumped back into reservoir 12 , from which it is recirculated until its pH, as measured by sensor 26 , has risen to a predetermined level. At this point, new cleaning fluid is introduced into system 10 from reservoir 13 , either manually or automatically through pumping system 29 .
[0037] FIG. 3 shows a system 10 that cleans two tubes 18 a and 18 b. However, it can be seen that system 10 can be configured to clean a single tube, or a section of tubes of any number.
[0038] For example, FIGS. 5 and 6 show a system 200 that is used to clean a section 210 of 6 tubes 224 . System 200 is configured in a “multiple loop” configuration. That is, system 200 includes three independent flow paths through section 210 . Each of tube pairs, or loops, 212 , 214 and 216 carries an independent flow path. Each tube 224 of loops 212 , 214 and 216 defines an inlet 220 and an outlet 222 . A plug 100 is sealingly mounted in each inlet 220 and each outlet 222 . The construction of plugs 100 is described in detail below. Each plug 100 defines a central passage through which fluid can flow through plug 100 and into or out of a tube 224 . An endpiece 226 is threaded onto the end of each plug 100 to facilitate connection between the inlet 220 or outlet 222 with connecting lines or hoses. Each endpiece 226 can be secured to its respective line using a conventional connector 21 . Connector 21 can be any known connector that is used to mount hardware to hoses, including the type used with compressed air hoses. These connectors use a sliding outer sleeve and ball bearings to attach the hose to a head. Connector 21 can be used in all embodiments of the system shown in the drawing.
[0039] System 200 includes a pump 228 that pumps fluid from a reservoir 224 through system 200 . A pair of hoses 230 carries fluid pumped by pump 228 . Hoses 230 are mounted to a manifold 232 . Manifold 232 defines outlets 234 , each of which is mounted to an inlet hose 236 . Each hose 236 is mounted to an endpiece 226 . Ball valves 223 are mounted in known fashion within each manifold inlet 225 and manifold main inlet 227 to prevent unintended reverse flow. Consequently, pump 228 pumps fluid into hoses 230 , through manifold 232 , through hoses 236 and endpieces 226 , and through plugs 100 into the interior of tubes 224 .
[0040] A U-shaped connecting hose 238 is mounted to the endpiece 226 mounted to the outlet 222 of an inlet pipe 224 a of each loop 212 , 214 and 216 and the endpiece 226 mounted to the inlet 220 of the outlet tube 224 b of the loop. As a result, fluid pumped through the inlet tube 224 a of each loop 212 , 214 and 216 exits an outlet 222 , through connecting hose 238 and into outlet tube 224 b. The fluid then flows through outlet tube 224 b, plug 100 , endpiece 226 , hose 236 , manifold 232 , hose 230 and back to reservoir 224 and re-circulated through pump 228 .
[0041] FIGS. 9 and 10 show a system 300 that is constructed in an “individual loop” configuration. The construction of system 300 is identical to the construction of system 200 , with the exception of the flow paths defined by system 300 . Rather than configuring pairs of tubes connected by U-shaped hoses to define flow paths, system 300 is configured to define a flow path corresponding to each tube. Thus, system 300 utilizes an inlet manifold 310 defining inlets 311 . Inlets 311 are connected to endpieces 226 via hoses 309 and couplings 21 , which are used to mount hoses 309 to endpieces 226 . Manifold 310 is used to distribute fluid to the inlets 312 of tubes 224 via plugs 100 . System 300 includes an outlet manifold 314 that defines outlets 315 that are connected to the end pieces 226 of the plugs 100 that are mounted to the outlets 320 of the tubes 224 . Outlets 315 are mounted to endpieces 226 via hoses 305 and couplings 21 , which are used to mount hoses 305 to endpieces 226 . Ball valves 322 are mounted in known fashion within each manifold inlet 311 and manifold outlet 315 to prevent unintended reverse flow. Manifold 314 collects fluid that has passed through tubes 224 , and directs the fluid through a single return line 316 back to the fluid reservoir 318 . Typically, line 318 is located outside the containment box (not shown) of the condenser. Consequently, fluid is pumped by pump 228 through inlet manifold 310 , tubes 224 , outlet manifold 314 , return line 316 and back to reservoir 318 .
[0042] Similarly, FIGS. 11 and 12 show a system 400 that is identical in construction to systems 200 and 300 , with the exception of the manner in which the flow path is defined. System 400 is constructed in a “continuous loop” configuration. System 400 defines a single flow path through tubes 224 . In other words, fluid flows through the tubes 224 of system 400 in completely “series” fashion. All fluid pumped through system 400 flows through all the tubes of the section being treated. A U-shaped connector 410 is employed to channel the flow through adjacent tubes 224 . To illustrate, FIGS. 11 and 12 show system 400 defining two rows, or layers, of tubes, upper row 412 and lower row 414 . System 400 pumps fluid serially through tubes 224 U of upper row 412 , and then through the tubes 224 L of lower row 414 . Pump 228 pumps fluid into the inlet 416 of first tube 418 . Fluid flows through tube 418 and into a connector 410 that directs the fluid into inlet 420 of second tube 422 . A second connector 410 directs fluid exiting tube 422 into the inlet 424 of a third tube 426 . A third connector 410 directs the fluid downwardly to the inlet of the first tube (not shown) of the lower row 414 . As with upper layer 412 , another U-connector (not shown) directs the fluid to the second tube (not shown) of row 414 . Finally, a fifth connector 410 directs the fluid to the inlet 428 of the sixth, and last, tube 430 . The fluid is returned to the fluid reservoir 432 via line 434 . As is well known in the industry, ball valves 436 are provided in lines 438 and 434 to prevent reverse flow.
[0043] Referring to FIGS. 7 , 8 , 13 and 14 a sealing plug 100 provided by the present invention can be used to seal the ends of tubes to provide fluid access to the interior of a tube. Sealing device 100 can be used in systems that circulate cleaning fluid through tubes to clean the interior surfaces of the tubes. As is described above, sealing device 100 can be used in systems of the type shown in the drawing, and to allow passage of the cleaning fluid into and out of the tubes. It should be understood, however, that plug 100 can be used in any system that introduces a fluid into tubes for any purpose.
[0044] Plug 100 includes a threaded core 102 made from a suitable plastic or metal material, such as plastic: Delrin or acetal 570 or metal: stainless steel. Core 102 defines a flange 104 at one end, and a threaded section 106 at the other end. At least one cylindrical sealing sleeve 108 is provided, which defines a central bore 110 , which is sized to be received along central section 112 of core 102 . At least one sleeve 108 is mounted on section 112 of core 102 . If more than one sleeve 108 is used, a plastic washer 113 is mounted between each pair of sleeves 108 . Where, as with the embodiment shown in the drawing, a pair of sleeves 108 is employed, a single washer 113 is mounted between sleeves 108 . Regardless of the number of sleeves 108 employed, a washer 114 is mounted on core 102 adjacent the end of the outermost sleeve 108 . Washer 113 will have a smaller diameter than 114 to enable the diameter of washer 113 to more closely match the diameter of sleeves 108 . A nut 116 is threaded onto the threaded end 106 of core 102 , and bears against washer 114 . The diameter of washer 114 is chosen to be larger than the inner diameter of the tubes in which plug 100 is mounted to facilitate placement of plug 100 in a consistent location with respect to the tubes. That is, washer 114 acts like a “stop” that prevents inadvertent placement of plug 100 to far within the tube. Washers 113 and 114 function as the bearing surfaces against which the force generated by nut 116 is exerted against the ends of sleeves 108 , which in turn operates to expand sleeves 108 and force them into sealing engagement with the interior of tube 118 (see, particularly, FIG. 8 ). The expansion of the sleeves 108 against the interior surface of tube 118 also operates to fix the position of plug 100 within tube 118 .
[0045] Core 102 defines a passage 120 through which fluid can pass through core 102 . Endpiece 226 includes a threaded section 600 which is threaded onto threaded section 106 of plug 100 to mount endpiece 226 to plug 100 . A hose or line 120 can then be mounted to endpiece 226 using a conventional coupling 21 .
[0046] To mount a plug 100 within a tube 118 , a sleeve 108 is mounted onto center section 112 of plug 100 . The length of section 112 and the number of sleeves 108 can vary. The length of section 112 will typically be between three and four inches and plug 100 will typically have one washer 113 separating two flexible bushings or sleeves 108 and an additional washer 114 separating sleeves 108 and nut 116 , which will typically provide an effective seal. These configurations can be changed to alter the nature of the seal as is well known in the art. Generally, the effectiveness of the seal between the plug 100 and a tube increases as the number of washers 113 increases and the length of the bushings 108 decreases. However, as will be appreciated by those in the art, the increased number of washers 113 will begin to compromise the effectiveness of the seal. A plug with two sealing sleeves 108 separated by a washer 113 will provide an effective seal in most situations. If it is found that the seal is not adequate, those in the art will appreciate how to modify the number and length of the sleeves 108 to improve the seal. For example, if a tube is severely eroded and, consequently, achieving a seal is difficult, the plug 100 may need to be made longer or more washers 113 will need to be added, which would mean more, and shorter, sleeves 108 would be provided on the plug 100 .
[0047] Flange 104 is inserted into a tube 118 that is to be cleaned, and a nut 116 is threaded onto threaded end 106 of plug 100 . As nut 116 is tightened, sleeves 108 expand radially to provide a seal between plug 100 and the interior of tube 118 . In this regard, the washers 114 provide bearing surfaces for the pressure exerted on sleeves 108 by nut 116 , and ensure more uniform expansion of sleeves 108 . When plugs 100 are fully mounted to each end of tube 118 , fluid is free to pass into and out of tube 118 .
[0048] Although the invention has been described with reference to the above embodiments, it will be apparent to one of the ordinary skill in the art that modifications to the described embodiments may be made without departing from the spirit or scope of the invention. For example, it is to be understood that changes may be made in details, including in matters of shape, size, and arrangement of parts in accordance with the appended claims. The foregoing description of embodiments of the invention have been presented only for purposes of illustration and description. These embodiments were chosen and described to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular uses contemplated. Accordingly, the scope of the invention will be defined by the attached claims not by the above detailed descriptions.
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A treatment system that treats the interior of one or more tubes of a tube bundle. The system circulates treatment fluid within the tubes being treated. A manifold distributes the treatment fluid among the tubes being treated in the case of treatment of more than one tube where the tubes are to be treated simultaneously. A device is provided that both seals the ends of the tubes being treated and forms a passage by which the treatment fluid is introduced into and removed from the tubes. The treatment system can be a tube cleaning system that removes foreign material from the interior of the tubes.
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This application is a continuation-in-part of application Ser. No. 08/697,464 filed on Aug. 26, 1996, now U.S. Pat. No. 5,704,690.
BACKGROUND OF THE INVENTION
The present invention relates in general to stackable furniture, and more specifically, to stackable arm chairs having removable seat cushions, the chairs constructed from synthetic yarns of polymer material having a natural wicker appearance which are suitable for use in a variety of environments such as outdoors. The yarns and weaves of the present invention are also disclosed in Applicant's pending Design application Ser. No. 056,425, filed on Jun. 28, 1996.
Natural wicker has been used in the manufacture of furniture, baskets and other articles for many centuries. Natural wicker articles are manufactured from the twigs or branches of various plants that are first soaked in water in order to make them pliable, then woven to form into the article and finally allowed to dry. Furniture manufactured from wicker offers greater comfort than furniture manufactured from other materials because of wicker's inherent compliancy. Further, wicker is light weight and reasonably strong, making it an important material in the manufacture of furniture.
In recent years, the popularity of wicker furniture has increased significantly. The casual, informal appearance of wicker has made it especially popular for use in enclosed porches and other informal settings in homes, hotels and other establishments. Natural wicker, however, has had limited use in the outdoor furniture market, including patio furniture, pool furniture and the like. This is because natural wicker softens and weakens when wet, and is more susceptible to rotting and mildew than many other natural and man-made furniture materials. Further, natural wicker furniture is expensive because of the cost of the raw natural wicker which must be harvested and treated. The cost of natural wicker furniture is also increased by the added step of moistening the wicker before weaving it into furniture.
Woven wicker typically comprises a warp yarn, i.e., a yarn running straight through the woven material and providing support, and a weft yarn, i.e., a yarn used as filler that is woven around the warp yarn. Numerous styles of weave are used in the manufacture of wicker furniture. The various styles of weave result in a different look, feel, strength and weight of the finished woven product. In a simple weave pattern, the warp yarns are spaced apart and arranged parallel to each other. The weft yarns are woven over and under alternating warp yarns. Adjacent weft yarns pass on opposite sides of a given warp yarn. Variations of this pattern, such as passing the weft yarn over two adjacent warp yarns, are known in the art.
Wicker is additionally used in the manufacture of furniture by covering structural members such as legs and arms by wrapping. Further, decorative open patterns may be incorporated into an article of furniture between the panels of woven material and the structural members.
A primary reason for the popularity of wicker is its unique, natural look. Inherent imperfections in the natural plant material used in manufacturing wicker furniture create random changes in coloration and texture across the surface of a given woven panel. The imperfections may reflect light differently from the surrounding areas of wicker, or may appear as local changes in color or hue within a woven wicker panel. The small nicks and knots present in a natural wicker yarn further create a unique, mildly rough "feel" to wicker.
Other materials have been used in the manufacture of wicker-like furniture. For example, metallic wire has been wrapped in natural rush or paper and woven to simulate natural wicker furniture. Like natural wicker furniture, furniture made in this manner may not be used in outdoor environments. In addition, the wrapping tends to tear and wear away from the wire, causing unsightly defects.
Polymer yarns have also been used to manufacture wicker-like furniture. In one example of a polymer yarn, a polyester filament cord is coated with a polyvinyl chloride (PVC) coating. Wicker-like furniture manufactured from such polymer yarns has been found to be strong, wear-resistant and relatively inexpensive. In addition, polymer wicker chairs may be used outdoors because the yarn is resistant to the effects of water and the environment. Wicker-like furniture manufactured from a smooth, monochrome polymer yarn, however, has an artificial look and feel. A woven panel of such furniture has a uniform, uninterrupted color and reflects light without variation across its surface. It is immediately evident that furniture manufactured from such yarn has been made from man-made materials, and the furniture has, in general, a "plastic" look. In addition, such panels have a smooth, silky feel, unlike the slightly roughened feel of natural wicker.
In order to overcome these deficiencies in synthetic yarns, a longitudinal color stripe has been added to the outside surface of a polymer yarn in order to give furniture manufactured from that yarn a more natural look. The stripe imparts a variation of color on the surface of a material woven from that yarn. The material, however, remains smooth and silky to the touch, unlike natural wicker and hence, still retained much of its "plastic" look.
In another example in order to impart a more natural feel to a panel woven from a polymer yarn, raised points have been formed on the outside surface of the polymer yarn, giving it a star-shaped cross section. Such raised points interrupt the light reflection by the yarn, decreasing the artificial look of a smooth yarn surface. The raised points, however, form a very rough surface on the woven material, making it uncomfortable and likely to catch delicate clothing. The surface color of the polymer yarn may have a motley look in different hues. In sum, no adequate yarn material has been suggested for the manufacture of a wicker-like article of furniture that has the look and texture or feel of natural wicker, but is durable and may be used in a variety of environments such as an outdoor setting.
Furniture such as chairs are often shipped from the manufacturer or distributor to the retail store and/or to the ultimate consumer in protective cardboard boxes. In the absence of the ability to stack these chairs, each chair would necessitate its storage in its own container. As a result, substantially increased storage space at warehouses, as well as truck space during shipping is required for these chairs. It would therefore be highly desirable to be able to stack a plurality of chairs into a single nested stack which would occupy approximately the same floor space as a container having a single chair therein. To this end, there is known a number of chairs which are stackable. For example, stackable chairs are disclosed in Rowland, U.S. Pat. No. 3,338,591; Wilson, U.S. Pat. No. 2,997,339; Barile, U.S. Pat. No. 5,524,963; Stafford, U.S. Pat. No. 3,053,493; Perry, U.S. Pat. No. 5,383,722; and Timmons, U.S. Pat. No. 374,129. Each of the aforementioned patents disclose stackable chairs which are specifically constructed without arm rests.
Chairs which have arm rests are desirable for many applications since the sidearms reduce fatigue of the person sitting in the chair and therefore increase the ability of the sitter to concentrate. In addition, certain chair designs lend themselves more suitable for those having arm rests, such as chairs having a wicker look. Accordingly, chairs having arm rests are desirable for many uses, for example, indoor and outdoor furniture where a particular look or style is desired, as well as to provide additional sitting comfort. However, in general, chairs having arm rests do not typically provide stackability because the arm rests interfere with the stacking arrangement and/or increase the stack height of the chairs to render stacking undesirable. There is known from Guichon, U.S. Pat. No. 5,044,691 and Sebel, U.S. Pat. No. 4,441,419 stackable chairs having armrests. In Sebel, the legs are formed with outwardly directed channels, the forward edge portion of each rear leg and the rearward edge portion of each front leg being extended upwardly beyond the seat to form rearward and forward portions of the corresponding arm rests. This construction allows the legs from adjacent chairs to be received within the outwardly directed channels to enable stacking of the chairs. However, this construction severely limits the ability to create stackable arm chairs of various designs. In Guichon, the front and rear legs are similarly constructed, with the rear legs passing through notched sections of the seat which communicate with the rear leg channels.
It has been found desirable to provide arm chairs with side panels which are substantially closed to create a pleasing appearance. To this end, there are known stackable arm chairs of the aforementioned type in which a relatively large opening is provided in the side panels to allow passage of the rear legs of another chair to accommodate stacking. However, because of the large size of these openings, such openings often detract from the aesthetic appearance of the chair. Although these stackable chairs may include a removable seat cushion, the thickness of the standard cushion is relatively small in comparison to the size of the opening. Thus, with or without a seat cushion, the enlarged openings in the side panels detract from the aesthetic appearance of the chair. In sum, there is unknown a stackable arm chair which is aesthetically pleasing, while at the same time allowing a greater degree of design flexibility than provided by the prior art stackable arm chairs and which provides greater consumer acceptance.
SUMMARY OF THE INVENTION
It is therefore broadly an object of the present invention to provide an arm chair which is suitable for stacking while providing an aesthetically pleasing appearance.
Another object of the present invention is to provide a stackable arm chair which retains versatility of design.
A yarn of indeterminate length is disclosed having a wicker look suitable to be woven into wicker-like articles such as the aforementioned stackable arm chairs and the like. In accordance with one embodiment, the yarn has an inner core and an outer coating having an outer surface. At least one groove is formed in the outer surface extending substantially in an axial direction on the yarn. The groove may vary in position around the circumference of the yarn, and may be interrupted in an axial direction along the yarn. The groove may furthermore have a generally rectangular, curved or other cross sectional shape.
The yarn additionally has a visual representation of a stripe of a color or visual appearance other than the color or appearance of the outer surface of the yarn, extending substantially in an axial direction along the yarn. The stripe may vary in position around the circumference of the yarn. Further, the stripe may be located within the groove, or may intersect the groove. The relative circumferential position of the groove and the stripe may vary at different axial positions along the yarn. The stripe may be continuous or interrupted in an axial direction along the yarn.
In accordance with one embodiment of the present invention there is described a stackable arm chair comprising a frame forming a seat, a back, a pair of front legs, a pair of back legs and a pair of side arms; a side wall extending between the seat and each of the side arms, each of the side walls having an opening adjacent the seat and a corresponding one of the back legs, the size of the opening cooperating with the height of a seat cushion positionable on the seat between the side arms such that the opening is substantially covered by the cushion, the opening being of sufficient size and location to permit passage therethrough of a corresponding back leg of another stackable arm chair of substantially the same construction for arranging the chairs in a nested stack thereof.
In accordance with another embodiment of the present invention there is disclosed a cushioned stackable arm chair comprising a frame forming a seat, a back, a pair of front legs, a pair of back legs and a pair of side arms; a side wall extending between the seat and each of the side arms, the side wall having an opening adjacent the seat and a corresponding one of the back legs; and a seat cushion supported on the seat between the side arms, the height of the cushion and the size of the opening cooperating with each other such that the opening is substantially covered by the cushion, the opening being of sufficient size and location to permit passage therethrough of a corresponding back leg of another stackable arm chair of substantially the same construction for arranging the chairs in a nested stack thereof.
In accordance with another embodiment of the present invention there is described a nested stack of at least two stackable arm chairs, each of the stackable arm chairs comprising a frame forming a seat, a back, a pair of front legs, a pair of back legs and a pair of side arms; a side wall extending between the seat and each of the side arms, each of the side walls having an opening adjacent the seat and a corresponding one of the back legs, the size of the opening cooperating with the length of a seat cushion positionable on the seat between the side arms such that the opening is substantially covered by the cushion, the opening being of sufficient size and location to permit passage therethrough of a corresponding back leg of the other of the at least two stackable arm chairs of substantially the same construction for arranging the chairs in the nested stack thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The above description, as well as further objects, features and advantages of the present invention will be more fully understood with reference to the following detailed description of a stackable arm chair having a removable seat cushion, the chair constructed from a yarn having wicker appearance, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a yarn according to one embodiment of the invention having one stripe and one groove;
FIG. 2 is a sectional view of the yarn of FIG. 1;
FIG. 3 is an elevation view of the yarn of FIG. 1;
FIG. 4 is a perspective view of a yarn according to another embodiment of the invention having two grooves and one stripe;
FIG. 5 is a sectional view of the yarn of FIG. 4;
FIG. 6 is an elevation view of the yarn of FIG. 4;
FIG. 7 is a perspective view of a yarn according to another embodiment of the invention having two grooves and two stripes;
FIG. 8 is a sectional view of the yarn of FIG. 7;
FIG. 9 is an elevation view of the yarn of FIG. 7;
FIG. 10 is a perspective view of the yarn according to another embodiment of the invention having three grooves and two stripes;
FIG. 11 is a sectional view of the yarn of FIG. 10;
FIG. 12 is an elevation view of the yarn of FIG. 10;
FIG. 13 is a perspective view of a yarn according to another embodiment of the invention having a stripe intersecting a groove;
FIG. 14 is a sectional view of the yarn of FIG. 13;
FIG. 15 is an elevation view of the yarn of FIG. 13;
FIG. 16 is a perspective view of the yarn according to the present invention showing the effect of the yarn being formed from foamed PVC material;
FIG. 17 is a plan view of a material according to the invention woven from polymer yarns having grooves and stripes;
FIG. 18 is a sectional view of the woven yarn taken along line 18--18;
FIG. 19 is a sectional view of the woven yarn taken along line 19--19;
FIG. 20 is perspective view of a cushioned arm chair constructed of yarn according to the invention;
FIG. 21 is a perspective view of a frame forming a stackable arm chair;
FIG. 22 is a perspective view of a stackable arm chair covered in woven material, constructed in accordance with one embodiment of the present invention;
FIG. 23 is front elevational view of the stackable arm chair;
FIG. 24 is a top plan view of the stackable arm chair;
FIG. 25 is a rear elevational view of the stackable arm chair;
FIG. 26 is a bottom plan view of the stackable arm chair;
FIG. 27 is a top plan view of the stackable arm chair showing a seat cushion thereon;
FIG. 28 is a perspective view of the stackable arm chair showing the seat cushion thereon;
FIG. 29 is a front elevational view of the stackable arm chair showing the seat cushion thereon;
FIG. 30 is a side elevational view showing three stackable arm chairs arranged in a nested forward stack;
FIG. 31 is a front elevational view showing three stackable arm chairs arranged in a nested forward stack;
FIG. 32 is a rear elevational view showing three stackable arm chairs arranged in a nested forward stack; and
FIG. 33 is a perspective view of a yarn formed in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION
Referring now to the drawings, there is shown in FIG. 1 a yarn designated generally as reference number 1 constructed in accordance with one embodiment of the present invention. The yarn 1 shown is constructed as an elongated body, such as of indeterminate length, having a core 3 surrounded by a PVC outer coating 2, for example, foamed PVC material which gives greater volume with less material. However, it is to be understood that the outer coating 2 may be formed of other synthetic materials if desired such as polyamides, polyesters and the like. The yarn may be made in a single step using a coextrusion process, as is known in the art. The inner core may include a single filament of polyester, or may include a plurality of polyester filaments bundled to form a single core 3. In addition, the core 3 may be formed of other materials than polyester, monofilament or stranded, such as polyamides and the like. The core 3 is designated to give the yarn 1 greater mechanical strength over yarns formed only of PVC material or the like. However, it is to be understood that the core 3 forms no part of the present invention and may be eliminated if desired. Although the yarn has been shown as cylindrical in shape, other shapes such as square, oval, triangular and the like can be used.
At least one groove 5 is formed on the outer surface 4 of the yarn. The width of the groove at the outer surface may vary from relatively narrow to much wider, for example, about 45°. The groove may have a shallow depth or deeper from the outer surface 4, and may have a cross section comprising a flat floor with radii 6 or may have a generally rounded cross section (not shown). The groove may be formed by a die during the coextrusion process, or may be formed later using a finishing die.
The groove 5 as shown in FIGS. 1 and 2 gives a natural feel to a material woven from the yarn of the invention. The corners 15 formed between the groove 5 and the outer surface 4 of the yarn closely simulates in feel the nicks found in natural wicker materials. Further, the groove itself forms an interruption in the smooth outer surface 4 of the yarn, reflecting light unevenly wherever it is exposed on the surface of material woven from the grooved yarn. The uneven light reflection creates a look closely paralleling the appearance of natural wicker.
Because the groove 5 is a concave feature or inward depression in the outer surface 4 of the yarn, the corners 15 are not so rough as to be uncomfortable to a person seated in a chair made from the yarn, and do not catch clothing. This is a significant advance over designs including convex features such as the star-shaped yarn of the prior art, which may abrade the user and catch clothing.
The groove 5 may have a wobble 18, as opposed to being straight as shown in FIG. 21, relative to the axis of the yarn, as shown is FIG. 6, in order to more closely duplicate the conditions on a natural wicker fiber. The wobble causes the groove to vary in position around the circumference of the yarn at various points along the axis of the yarn. The wobble of the groove 5 prevents regular patterns from being formed in a material woven from the grooved yarn, instead presenting a random appearance and disappearance of the groove on the surface of the woven material.
In order to further increase the random appearance and disappearance of the groove 5 on the woven material, interruptions 10, shown in FIGS. 4 and 6, may be placed at spaced apart locations along the groove. The interruptions 10 may be of any length and occurrence as desired. In addition to further randomize the light reflected by the woven material, the interruptions 10 form additional corners 16 that present tactile features in an axial direction along the yarn, as compared to the corners 15 that present tactile features in a tangential direction. The corners 16 are detected by a user when running the hand in an axial direction along the yarn, and thus closely simulate the random nicks found on natural wicker materials.
In an alternative form of groove interruption (not shown), a smooth transition is made between the groove 5 and the outer surface 4. This embodiment provides a less prominent tactile feature in the axial direction of the yarn. Accordingly, it can be appreciated that the groove 5 can be constructed in a variety of forms which may be randomly oriented and arranged on the outer surface 4.
In addition to the grooves 5, at least one stripe 7 is placed on the outer surface 4 of the yarn 1 in order to further enhance the natural look of material woven from the yarn 1, as shown in FIGS. 1-3. The stripe 7 is of a different color or different hue than that of the outer surface 4. In this regard, the stripe 7 provides a visual representation or visual appearance of an area being distinguished from the remaining surface of the yarn 4. For example, on a natural or tan-colored wicker yarn, a black or brown stripe may be used. In another example, a yellow stripe may be used on a green yarn or a gray stripe on a white yarn. As the yarn is woven into a material, the stripe appears at random locations on the surface of the material, interrupting the otherwise uniform color of the surface. These random interruptions simulate the color variations and imperfections of natural wicker fiber, making the woven material closely resemble wicker.
The stripe 7 may have a wobble 17, as opposed to being straight, with respect to the axis of the yarn, as shown in FIG. 3. The wobble further randomizes the appearance of the stripe on the surface of the woven material. In one example of the yarn, the magnitude of wobble of the stripe 7 is approximately equal to that of the grooves.
The stripe 7 may be molded into the yarn during the coextrusion process with the core 3 when present, and may extend deep into the yarn as a color portion 13 of the outer coating 2, shown in FIG. 5. Such a configuration is advantageous over painting or inking the stripe 7 on the yarn which may also be used, in that the color portion 13 may not be removed by wear on the outer surface 4. The stripe 7 may incorporate interruptions 11, as shown in FIGS. 4 and 6. The interruptions may be of any length and occurrence as desired. The interruptions 11 simulate the interrupted nicks and scratches appearing on natural wicker fibers.
Additional stripes and/or grooves may be incorporated in the yarn in order to further enhance the natural appearance of a fabric woven from the yarn. In the example shown in FIGS. 4-6, two grooves 5 and 12, located by way of one example approximately 180 degrees apart, are formed on the yarn 19 in conjunction with stripe 7. The use of two grooves increases the frequency that the groove appears on a given surface of the woven material, making the woven material feel and appear rougher.
Additional stripes may be placed on the yarn, as shown in FIGS. 7-9. Stripes 7 and 20 are placed on the wicker yarn 25 by way of one example approximately 180 degrees apart. The use of two stripes increases the frequency that a stripe appears on a given surface of the woven material, giving the woven material the appearance of having a larger number of darker or differently colored areas. Additional stripes and/or grooves may be added in order to achieve the desired effect on the finished material. For example, in FIGS. 10-12, three grooves 5, 12, 21, and two stripes 7, 20, are placed around the circumference of the wicker yarn. The stripes 7, 20 wobble with respect to the axis of the wicker yarn as previously described. The grooves 5, 12, 21 as shown do not wobble. The configuration shown in FIGS. 10-12, when woven into a wicker-like material, provides surfaces that are very rough in both look and feel, with a medium amount of random interruption in the color of the material. Other combinations of stripes and grooves on a wicker-like yarn may be utilized in order to achieve varying amounts of roughness and color interruption. The invention is therefore not limited to the examples provided herein, which are only exemplary of the present invention.
A stripe and a groove provided on a single wicker yarn may remain separated as shown in FIGS. 1-2, or may intersect as shown in FIGS. 13-15. Stripe 31, shown in FIGS. 13-15, is superimposed on the groove 32 at various locations along the axis of the yarn 30. The appearance of a material woven from the yarn 30 is further altered by the changing surface upon which the stripe 31 appears. As the stripe 31 makes a transition from the outer surface 4 of the yarn 30 to the groove 32, the appearance of the stripe changes, giving a different look to the woven material. The use of a stripe intersecting a groove may be combined with the use of multiple grooves, such as grooves 32, 33, shown in FIGS. 13-15, and may also be used in combination with various numbers of grooves and stripes, in order to produce a desired effect on a woven material.
As previously described, the yarn 1 is preferably constructed from foamed PVC material which is generally softer than unfoamed PVC material. Foamed PVC material provides about 15% more bulk volume thereby resulting in cost savings. As a result of the lack of uniformity in the foaming of the PVC material during the extrusion process, the resulting yarn lacks a uniform cylindrical appearance. Specifically, as shown in FIG. 16, the outer surface of the yarn is deformed by the absence of a uniform cylindrical surface, such as by having undulations and/or mounds. Not wishing to be bound by any particular theory, it is believed that due to the small volume of PVC material, the PVC material density during the foaming process varies along the length and/or thickness of the yarn so as to cause the deformed shape. This deformed shape results in the yarn having a more natural look to that of real wicker. Yarn constructed from foamed PVC material having at least one random stripe and at least one random groove pursuant to the present invention provides the yarn with a more natural and pleasing appearance which overcomes the objections from the prior yarns used in the construction of casual furniture.
A woven material 50 of the invention comprises warp yarns, such as yarns 40, 41 and weft yarns, such as yarns 42, 43, as shown in the example of FIGS. 17-19. The weave pattern shown in these figures is by way of example, and those skilled in the art will recognize that other weave patterns may be utilized to meet various requirements of strength, look, feel, texture, design, and weight. Warp yarns 40, 41 are placed at even, spaced apart intervals and traverse the material in a substantially straight path. Weft yarns, or "filler" yarns 42, 43 are woven on alternating sides of the warp yarns 40, 41. For example, weft yarns 42 pass on top of the warp yarn 40, while weft yarns 43 pass beneath the warp yarn 40, as shown in FIG. 17. Weft yarns 42 then proceed beneath the warp yarn 41, while weft yarns 43 proceed on top of the warp yarn 41. This weaving pattern is continued throughout a given panel of material. As can be seen in the plan view of FIG. 17, grooves 45 and stripes 46 on the weft yarns 42, 43 impart a random "natural" wicker look to the woven material. In the example shown in FIGS. 17-19, each weft yarn has a single groove and a single stripe, both of which wobble with respect to the yarn axis. Additional grooves and/or stripes may be added in order to increase the effects each of those elements has on the overall look of the material 50.
It is to be understood that it is not required that the warp yarns 40, 41 include stripes and grooves of the present invention. In this regard, the warp yarns 40, 41 can be convention yarns as they are generally concealed by the weft yarns 42, 43. Similarly, it is not required that all of the weft yarns 42,43 be constructed in accordance with the present invention. Other conventional yarns can be combined with the weft yarns 42, 43 to give the weave 50 a particular look which still retains a wicker look and feel without departing from the present invention.
The wicker-like yarns to be woven into material, such as material 50, may if desired be heated before the weaving process, or may be woven immediately after the coextrusion process before the yarns cool. By weaving the yarns in a heated state, adjacent weft yarns 42, 43 adhere to each other and adhere to the warp yarns 40, 41. In this way, a more stable woven material 50 is produced. Alternatively, an adhesive may be used between the yarns in order to produce similar results if desired.
A furniture item of the invention, such as the wicker-like chair 100 shown in FIG. 20, may be produced from a rigid skeletal frame 110 covered by weaving yarns of the invention into woven material panels such as panel 101 forming the back of the chair 100, and panel 104 forming the seat of the chair which are attached to the frame. The chair has a look and feel of natural wicker because of the use of stripes and grooves on the yarn used in making the panels. Yarns with stripes and/or grooves may also be used in wrapping the structural members of the frame such as legs 102 and arms 103, giving those members a natural wicker look as well. Such yarns may also be used in forming lattice work such as the lower chair back 103, which is often formed using the warp yarns of adjacent woven panels. Other furniture items such as couches, tables, benches, stools, trunks, and the like can also be produced using the yarn disclosed in accordance with the present invention so as to have a wicker look.
Chair 100 may be fabricated from wicker yarns of the invention having colors other than the color of natural wicker. Such chairs have the advantages of color coordination offered by a painted wicker chair, while maintaining the random coloration and the slightly rough feel of natural wicker.
Referring now to FIGS. 21-26, there is illustrated pursuant to another aspect of the present invention an arm chair constructed to be stackable and which is suitable for manufacture using any of the yarns as thus far described. The stackable arm chair 120, as shown in FIG. 21, is constructed from a rigid hollow tubular frame 122 which, as to be described hereinafter, provides the stackable arm chair 120 with a seat, a back, a pair of front legs, a pair of back legs and a pair of side arms. The seat 124 is delineated by a connecting front member 126, a parallel spaced apart back member 128 and a pair of parallel spaced apart side members 130, 132. As shown, the front member 126 is somewhat longer than the back member 128, the side members 130,132 being connected to the front and back members slightly inwardly of their terminal ends. As a result, the side members 130, 132 taper inwardly from the front member 126 to the back member 128 such that the forward portion of the seat 124 is wider than the rear portion of the seat.
The front legs 134, 136 are constructed as parallel spaced apart vertical members joined to the free ends of the front member 126 and have outwardly turned extensions 137 providing the front legs with an L-shape. The front legs 134, 136 are arranged generally vertical to the floor as viewed from the front and side of the stackable arm chair 120.
The back legs 138, 140 are constructed from an angular member attached to the free ends of the back member 128. The back legs 138, 140 have generally parallel spaced apart upper members 142 extending vertically from the back member 128 as viewed from the front and side and generally parallel spaced apart lower members 144. The lower members 144 are arranged at a rearwardly extending angle as viewed from the side and extend generally vertical from the back member 128 as shown from the rear of the stackable arm chair 120. As the front member 126 is longer than the back member 128, the distance between the front legs 134, 136 is greater than the distance between the back legs 140, 144. This offset between the front legs 134, 136 and the back legs 138, 140 in conjunction with the rearward tapering of the side members 130, 132 facilitates the stackability of the arm chair 120 as to be described hereinafter.
A generally U-shaped member 146 includes a center section 148 connected across the free ends of the upper members 142 of the back legs 138, 140 and a pair of curved spaced apart side arm members 150, 152 forming the side arms 154, 156 of the arm chair 120. The free ends of the side arm members 150, 152 are attached to the free ends of the extensions 137 of the respective front legs 134, 136. The side arm members 150, 152 are spaced apart wider at their mouth where they connect to the extensions 137 then where they form the center section 148. This arranges the side arms 154, 156 outwardly of the side members 130, 132. The upper members 142 of the back legs 138, 140, the back member 128 and center section 148 of U-shaped 146 delineate the back 157 of the arm chair 120.
A secondary frame provides attachment support for woven material utilized in covering the tubular frame 122. Specifically, a generally U-shaped elongated rod 158 having a shape conforming substantially to the shape of the U-shaped member 146 is connected thereto in underlying relationship by means of a plurality of spaced apart ribs 160. Another secondary support frame is positioned between the front and back legs 134, 136, 138, 140 underlying the seat 124. This secondary frame is constructed from a front rod 162 connected between the front legs 134, 136, a back rod 164 connected between the back legs 138,140 and a pair of side rods 166, 168 arranged in parallel spaced apart relationship connected between the front rod 162 and back rod 164 inwardly of their terminal ends. An additional front rod 170 may be positioned between the front legs 134, 136 underlying front rod 162.
Referring now to FIGS. 22-26, the tubular frame 122 of the stackable arm chair 120 is covered by weaving yarns as previously described and illustrated into woven material panels which are attached to the frame. More specifically, one woven material panel forms the seat 124 by being attached to the back and side members 128, 130, 132 and extending over the front member 126 to where it is ultimately attached to front rod 170. In addition to forming the seat 124, there is also thus formed a front panel 172 or skirt between the front legs 134, 136. A pair of side skirts 174, 176 are formed from secondary woven material panels attached between the side members 130, 132 and corresponding side rods 166, 168. The back 157 of the stackable arm chair 140 is formed from a woven material panel which is wrapped about the U-shaped member 146 and attached along its upper edge to rod 158. The bottom edge of the woven material panel is attached to back rod 164 thereby completing the back 157 of the arm chair 120. The woven material panel also forms a pair of side panels 178, 180 which is provided as an integral extension of the back 157 and forms a front portion of the side skirts 174, 176. An opening 182, 184 is provided in each of the side panels 178, 180. The openings 182, 184 are defined on two sides by the pair of side members 130, 132 and the upper members 142 of the rear legs 138, 140. The other two sides of the openings 182, 184 are bound by a terminal edge of the side panels 178, 180 which may be secured by a suitable rod (not shown) attached, for example, between the rear legs 138, 140 and side rods 166, 168.
As best shown in FIGS. 24 and 26, the side panels 178, 180 taper outwardly from the seat 124 as a result of the side arm members 150, 152 of the U-shaped member 146 being positioned outwardly of the side members 130, 132 which form the sides of the seat. This arrangement allows the openings 182, 184 to extend in both a horizontal and vertical plane. The extent of the openings 182, 184 in the horizontal plane are best shown in FIG. 24, while the extent of the openings in the vertical plane is best shown in FIG. 22. As the openings 182, 184 are defined within both horizontal and vertical planes, there is provided a three dimensional space between the side panels 178, 180 and the side members 130,132 forming the seat 124 as generally indicated by the dotted circular lines 186 in FIG. 24. This three dimensional space, as to be described hereinafter, allows for the stackability of the arm chairs 120.
Referring to FIGS. 27-29, the stackable arm chair 120 is adapted to be used in association with a conventional seat cushion 188. The seat cushion 188 is of standard thickness, e.g., about 31/2-41/2 inches as conventionally used in cushioned outdoor patio furniture. As shown, the size of the openings 182, 184 cooperate with the height and size of the seat cushion 188 such that the openings are substantially blocked from view thereby eliminating the objectionable appearance of the opening. As shown in FIG. 27, the size of the seat cushion 188 is sufficient to substantially cover the openings 182, 184 in the horizontal plane. Similarly as shown in FIGS. 28 and 29, the size of the seat cushion 188 is such to cover the openings 182, 184 in the vertical plane. In other words, the volume of the three dimensional space created by the openings 182, 184 in both horizontal and vertical planes are substantially occupied by a portion of the seat cushion 188. This construction maintains the ornamental and aesthetic characteristics of the stackable arm chair 120 without affecting the ease and simplicity of the stackable feature of the arm chairs.
Referring now to FIGS. 30-32, the stacking of the arm chairs 120 in a nested stack will now be described. One objective of stackable chairs in general is to allow the nesting of the chairs in a single stack which occupies a minimum of volume thereby minimizing the size of the storage container and, hence, the space occupied on common carriers during shipping resulting in lower transportation costs. The arm chairs 120 are nested into a single stack by inserting the lower members 144 of the back legs 138, 140 through the three dimensional openings 182, 184 at the location defined by the dotted circular lines 186. In this arrangement, seats 124 and backs 157 of the nested arm chairs 120 will be arranged adjacent one another in overlying relationship. As shown in FIGS. 31 and 32, the front legs 134, 136 and back legs 138, 140 of the nested arm chairs 120 are arranged substantially in alignment with each other within a respective common plane 190, 192, one behind the other. Similarly, the U-shaped members 146 of adjacent nested arm chairs 120 are arranged in substantial alignment with each other, one above the other. As a result of the foregoing construction, the arm chairs 120 are nested as tightly as possible with one another so as to minimize the overall space required by a set of, for example, four nested chairs, which are typically sold as a set. The close nesting of the arm chairs 120 is further facilitated by the absence of any cross bracing between the front and back legs 134, 136, 138, 140 as is conventional with known chair construction.
As the arm chairs 120 are nested with one another, they form what is commonly referred to as a forward stack. As shown in FIG. 30, the nested arm chairs 120 progressively move forward in the stack, as well as upwardly in height. However, because of the close nesting of the arm chairs, the forward and upward displacement of the arm chairs 120 is minimal, thereby minimizing the overall volume occupied by the nested arm chairs.
Although the stackable arm chairs 120 have been described with respect to a particular ornamental appearance and woven material panels, it is to be understood that other designs and shapes, including using other woven material panels from other materials than those described herein encompassing other weaves and yarns may be included in the stackable arm chairs pursuant to the present invention. That is, the present invention is not intended to be limited by any particular woven material panels, yarns or the overall shape of the stackable arm chair 120 illustrated. For example, although the yarn has been shown as generally cylindrical in shape, other shapes such as square, oval, triangular and the like can be used.
Referring now to FIG. 33, there is shown a perspective view of a yarn 200 in accordance with another embodiment of the present invention. The yarn 200 can be constructed generally pursuant to any one of the previously described embodiments. In this regard, the yarn 200 can be constructed from a variety of synthetic materials such as polyamides, polyesters and the like. Preferably, the yarn 200 is constructed from foamed PVC material about a center core 3 such as a single filament of polyester or a plurality of polyester filaments bundled to form the core. The yarn 200 may also be provided with one or more grooves 5 and/or stripes 7 in the manner as previously described.
In forming the woven material 50 as shown in FIG. 17, the weft yarns 42, 43 are provided as having a different color from the warp yarns 40, 41. By way of example only, the outer surface of the weft yarns 42, 43 may be green, while the outer surface of the warp yarns 40, 41 may be bone.
During the weaving process, the warp yarns 40, 41 are pulled through the weft yarns 42, 43 within the woven material 50. As the warp yarns 40, 41 are pulled through the woven material 50, there is created friction with the weft yarns 42, 43. This friction results in the random and non-uniform transfer of small portions of the material forming the weft yarns 42, 43 onto the outer surface of the warp yarns 40, 41 as generally designated at locations 202. This random and non-uniform transfer of the different colored material from the weft yarns 42, 43 to the warp yarns 40, 41 creates a more natural and unique attractive appearance to the warp yarns and the overall woven material 50. As a result, there is provided an overall enhanced pleasing appearance to the woven material 50. This effect is greater depending upon the extent of the contrast color between the weft and warp yarns. It is contemplated that a greater amount of transfer of material from the weft yarns 42, 43 to the warp yarns 40, 41 will be achieved by constructing the yarns from foamed material, such as PVC material, which is generally softer than non-foamed materials. Accordingly, by constructing the woven material 50 from foamed PVC material having an irregular surface, including one or more stripes 7 and/or one or more grooves 5 along with contrasting colors, the woven material can be provided with a unique look heretofore unknown.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that the embodiments are merely illustrative of the principles and application of the present invention. It is therefore to be understood that numerous modifications may be made to the embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the claims.
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A stackable arm chair is constructed from the combination of a frame which supports woven material to form the chair's seat, back and side arm portions. Openings provided in the side arm portions enable passage of the rear legs of an adjacent arm chair to provide a nested forward stack occupying a minimum of volume. The openings are configured and dimensioned so as to cooperate with a conventional cushion to block the openings from view thereby eliminating the conventional stackable chair appearance.
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PRIORITY
This application claims priority to an application entitled “Hinge Device for Display Rotation Type Mobile Phone” filed with the Korean Intellectual Property Office on Jan. 25, 2005 and assigned Serial No. 2005-6766, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a plate-type hinge device for a display for a rotation type mobile phone comprising main and sub-display devices.
2. Description of the Related Art
Generally, the term “mobile communication terminals” refer to mobile phones or handheld devices used for mobile wireless communications. The mobile communication terminals are classified into a bar type, a flip type and a folder type according to their construction. A bar-type mobile terminal has a bar-shaped single housing. A flip-type mobile terminal has a bar-shaped housing and a flip rotatably connected to the housing by a hinge. A folder-type mobile terminal has a bar-shaped housing and a folder rotatably connected to the housing by a hinge.
Recently, new designs such as a rotation (or swing) type and a slide type have been developed to meet the diverse needs and tastes of users. The rotation type has a pair of facing housings, one of which is rotatable on the other housing. The slide type has a pair of housings, one of which slides in relation to the other housing in a longitudinal direction to open or close the terminal. Such diverse types of mobile communication terminals are easily understandable by those skilled in the relevant art.
Mobile communication terminals with small and light designs have gained popularity for their improved portability. These small and light terminals are more convenient during a voice call or video-conference.
As illustrated in FIGS. 1 to 3 , a conventional mobile phone in display rotation type comprises a main housing 10 with a first hinge axis Al, a folder 20 and a connection member 30 . The main housing 10 is provided with a plurality of key buttons 11 and a microphone 12 . The connection member 30 connects the folder 20 to the main housing 10 in such a manner that the folder 20 can rotate around the first hinge axis Al in a direction to be closer to or away from the front surface of the main housing 10 . The connection member 20 has a second hinge axis A 2 around which the folder 20 can rotate in contact with the connection member 20 . The folder 20 comprises an LCD 21 and speakers 22 .
The connection member 30 also has a hinge module 40 mounted therein to make the folder 20 rotatable around the second hinge axis A 2 .
To better view moving images, video or mobile game images, a user can rotate the display device of the folder 20 in a direction providing a wider display (i.e., a landscape display mode).
However, such a conventional rotation type mobile phone has a single display device on the internal surface of the folder. When the folder is closed, the display device cannot be used. If an additional display device is provided on the external surface of the folder, the size and thickness of the hinge module is increased, an undesirable side effect in light of consumer demand for smaller and lighter terminals. In addition, such an additional display device will limit design variations and improvements for mobile phones.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a plate-type hinge device with reduced size and thickness which is useful for a display rotation type mobile phone comprising main and sub-display devices and which meets the demand for a slim and small mobile phone design.
Another object of the present invention is to provide a hinge device for a display rotation type mobile phone, which has both rotation and stopper functions, thereby reducing the number of parts to manufacture the mobile phone in a slim design and reducing the manufacture cost.
To accomplish the above objects of the present invention, there is provided a hinge device for a display rotation type mobile phone including a main housing, a folder having a main display device and rotatable around a hinge axis extending in a direction perpendicular to the length of the main housing and a connection member for rotatably connecting the folder to the main housing, said hinge device including: a first hinge member; a second hinge member rotatably connected to the first hinge member; a swing washer interposed between the first and second hinge members to rotatably connect the second hinge member to the first hinge member and providing an elastic force acting to rotate the folder; and a swing bush engaged into the first hinge member sequentially connected to the swing washer and the second hinge member.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of a conventional rotation type mobile phone in closed state;
FIG. 2 is a side view of the mobile phone in FIG. 1 ;
FIG. 3 is a plan view of the conventional rotation type mobile phone of FIG. 1 in an opened state with a 90° swiveled folder;
FIG. 4 is an exploded perspective view of a hinge device used for a display rotation type mobile phone according to an embodiment of the present invention;
FIG. 5 is an enlarged and exploded perspective view of part A in FIG. 4 ;
FIG. 6 is a perspective view showing the assembly of a hinge device for a display rotation type mobile phone according to an embodiment of the present invention;
FIG. 7 is a perspective view showing the rear side of a first hinge member of a hinge device used for a display rotation type mobile phone according to an embodiment of the present invention;
FIG. 8 is a perspective view of a hinge device of a display rotation type mobile phone according to an embodiment of the present invention when a folder is not swiveled;
FIG. 9 is a fragmentary perspective view of a hinge device of a display rotation type mobile phone according to an embodiment of the present invention when a folder is not swiveled;
FIG. 10 is a plan view of the hinge device in FIG. 9 ;
FIG. 11 is a perspective view, partially in cross section, showing a swing washer of a hinge device used for a display rotation type mobile phone according to an embodiment of the present invention;
FIG. 12 is a perspective view of a hinge device of a display rotation type mobile phone according to an embodiment of the present invention when a folder is swiveled 90°;
FIG. 13 is a perspective view, partially in cross section, showing a hinge device of a display rotation type mobile phone according to an embodiment of the present invention when a folder is swiveled; and
FIG. 14 is a plan view of the hinge device in FIG. 13 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same elements, although depicted in different drawings, will be designated by the same reference numeral or character. Also, in the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention unclear.
As illustrated in FIGS. 4 and 5 , a hinge device 100 comprises first and second hinge members 200 and 300 , a swing washer 400 and a swing bush 500 . The first hinge member 200 is mounted underneath a connection member 30 extending in a longitudinal direction. The connection member 30 has a disc-shaped mount panel 30 b under which the first hinge member 200 can be mounted. The second hinge member 300 is fitted into a connection hole 20 a formed on a folder 20 . The swing washer 400 facing the first hinge member 200 connects the second hinge member 300 rotatably to the first hinge member 200 . The swing washer 400 interposed between the first hinge member 200 and the second hinge member 300 provides an elastic force acting to rotate the folder 20 . The swing bush 500 is engaged into the first hinge member sequentially coupled to the swing washer 400 and the second hinge member 300 .
As illustrated in FIGS. 4 , 6 and 7 , the first hinge member 200 has a through hole 201 , a plurality of washer projections 202 , a stopper projection 203 and a plurality of screw connection portions 204 . The through hole 201 is formed at the center of the first hinge member 200 so that the swing bush 500 can be engaged therein. The washer projections 202 are preferably spaced at equiangular intervals along the circumference of the through hole 201 . The washer projections 202 in a domelike shape are smoothly inserted into or released out from washer recesses formed on the swing washer 400 according to the rotation of the folder 20 . The stopper projection 203 is formed at a specific position of the periphery of the through hole 201 to restrict the rotation of the second hinge member 300 by interrupting first and second stopper portions 302 a and 302 b formed on the second hinge member 300 . The screw connection portions 204 are formed at the periphery of the first hinge member 200 to secure the first hinge member 200 to the connection member 30 by means of screws 600 .
As illustrated in FIGS. 4 and 8 - 10 , the second hinge member 300 has a through hole 301 , a washer receiving groove 302 , a plurality of washer fixing holes 303 and a plurality of fixing projections 304 . The through hole 301 is formed at the center of the second hinge member 300 . The washer receiving groove 302 is formed along the outer circumference of the through hole 301 to receive the swing washer 400 . The swing washer 400 is received in the washer receiving groove 302 , with the insertion of washer recesses 401 projected downward from the swing washer 400 into the washer fixing holes 303 . The washer fixing holes 303 are formed at equiangular intervals on the surface of the washer receiving groove 302 along the outer circumference of the through hole 301 . The fixing projections 304 are formed adjacent to the washer fixing holes 303 to be inserted and fixed into fixing holes 402 .
As illustrated in FIGS. 12-14 , the second hinge member 300 has the first and second stopper portions 302 a and 302 b on the surface of the washer receiving groove 302 . If the second hinge member 300 is turned clockwise about the hinge axis A 2 , the first stopper portion 302 a will be interrupted by the stopper projection 203 of the first hinge member 200 where the swing washer 400 is turned 90 degrees. If the second hinge member 300 is turned counterclockwise about the hinge axis A 2 , the second stopper portion 302 b will be interrupted by the stopper projection 203 of the first hinge member 200 where the swing washer is returned to its original position.
In addition, a plurality of screw connection portions 305 are formed at the periphery of the second hinge member 300 to secure the second hinge member 300 to the folder 20 by means of screws 600 .
As illustrated in FIGS. 5 and 11 , the swing washer 400 has a plurality of washer recesses 401 , a plurality of fixing holes 402 and a plurality of elastic members 403 . The washer projections 202 of the first hinge member 200 are inserted into the washer recesses 401 which are spaced at equiangular intervals on the swing washer 200 . In addition, the fixing projections 304 of the second hinge member 300 are inserted into the fixing holes 402 formed adjacent to the washer recesses 401 . The elastic members 403 are provided at equiangular intervals along the circumference of the swing washer 400 to provide an elastic force acting to rotate the second hinge member 300 .
As illustrated in FIG. 11 , the elastic members 403 are preferably plate springs each having a fixed end 403 a and a free end 403 b. The fixed end 403 a of the plate spring is fixed to the swing washer 400 . The free end 403 b is protruded downward in the same direction of the hinge axis A 2 to apply pressure to the bottom surface of the washer receiving groove 302 . The elastic members 403 , i.e., the plate springs, are disposed symmetrically with respect to the hinge axis A 2 .
As illustrated in FIG. 12 , when the user turns the folder 20 about the hinge axis A 2 , the folder 20 is placed in a direction perpendicular to the length of the connection member 30 . At this time, the connection member 30 with the folder 20 turned has a T-shape, or a “⊥” shape.
Hereinafter, the operation of the hinge device for a display rotation type mobile phone having the above structure will be explained in detail with reference to FIGS. 4-14 .
Referring to FIGS. 4 and 5 , in the hinge device 100 for a display rotation type mobile phone, the first hinge member 200 is sequentially connected to the swing washer 400 and the second hinge member 300 . In this condition, the swing bush 500 is engaged into the first hinge member 200 . The second hinge member 300 is secured onto the folder 20 having a main display device 21 by tightening up the screws 600 into a plurality of screw connection portions 305 .
As illustrated in FIG. 4 , the first hinge member 200 is secured to the connection member 30 having a sub-display device 30 a by tightening up the screws 600 into a plurality of screw connection portions 204 . The connection member 30 has a disc-shaped mount panel 30 b under which the first hinge member 200 is mounted.
When the folder 20 is turned 90 degrees clockwise around the hinge axis A 2 as illustrated in FIG. 12 , the second hinge member 300 is turned together as illustrated in FIGS. 13 and 14 . At this time, the swing washer 400 is also turned.
As illustrated in FIG. 13 , the washer projections 202 of the first hinge member 200 are inserted into the washer recesses. With the turning of the swing washer 400 , the washer recesses 401 release from the initially received washer projections 202 and move to receive the next washer projections 202 .
As illustrated in FIG. 14 , the washer projections 22 are spaced at equiangular intervals along the outer circumference of the through hole 201 of the first hinge member 200 . The washer recesses 401 are also spaced at equiangular intervals so that the washer projections 22 can be inserted into the facing washer recesses 401 .
As illustrated in FIG. 13 , the washer projections 202 are formed in a domelike shape to be smoothly inserted into, and released out from, the washer recesses 401 .
Also, as illustrated in FIG. 11 , the elastic members 403 formed on the swing washer 400 provide a clamping force acting to place the washer recesses 401 to receive the corresponding washer projections 202 . The elastic members 403 are preferably plate springs formed at equiangular intervals along the periphery of the swing washer 400 . Each plate spring 403 has one end 403 a fixed to the swing washer 400 and the other end 403 b which is a free end protruded downward in the same direction of the hinge axis A 2 to apply pressure to the bottom surface of the washer receiving groove 302 .
When the folder 20 is turned, the second hinge member 300 is also turned until the first stopper portion 302 a is interrupted by the stopper projection 203 of the first hinge member 200 . At this time, the connection member 30 with the folder 20 turned has an upside-down T-shape, or a “⊥” shape as shown in FIG. 12 . If the folder 20 is turned around the hinge axis A 2 in a reverse direction, the second hinge member 300 and the swing washer 400 turn together. Then, the washer recesses 401 will move to receive the next washer projections 202 . The second hinge member 300 turns until the second stopper section 302 b is interrupted by the stopper projection 203 of the first hinge member 200 as shown in FIG. 12 .
Consequently, the folder 20 is returned to its original position and direction. Since the plate springs 403 apply a clamping force on the washer recesses 401 receiving the washer projections 202 , the folder 20 can be maintained in its original position and direction.
As explained above, a hinge device for a display for a rotation type mobile phone is provided in a plate shape having a sub-display device. The hinge device improves efficiency and ease of use. As compared to a conventional hinge module, the hinge module according to the present invention has reduced size and thickness, thereby enabling a slim and small mobile phone design. Moreover, the hinge member having both rotation and stopper functions can reduce the number of parts to manufacture the mobile phone with a slim design.
Although preferred embodiments of the present invention have been described 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, including the full scope of equivalents thereof. The hinge device according to the present invention can be used for any handheld mobile terminals.
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Disclosed is a hinge device for a display rotation type mobile phone comprising a main housing, a folder having a main display device and rotatable around a first hinge axis extending in a direction perpendicular to the length of the main housing and a connection member for rotatably connecting the folder to the main housing, said hinge device including a first hinge member; a second hinge member connected to the first hinge member which allows and restricts the rotation of the second hinge member; a swing washer interposed between the first and second hinge members to rotatably connect the second hinge member to the first hinge member and providing an elastic force acting to rotate the folder; and a swing bush engaged into the first hinge member sequentially connected to the swing washer and the second hinge member.
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BACKGROUND OF THE INVENTION
This invention relates to land based gas turbines used for power generation and, specifically, to a device that protects liquid fuel from convective, conductive and radiation heat transfer loads.
It has been found that heat loading into the fuel components of the gas turbine engine are sufficient to form coke within the components, resulting in loss of turbine performance. The inventors are aware of no prior attempts to solve this problem.
BRIEF DESCRIPTION OF THE INVENTION
This invention relates to a device that is designed to provide an increase in thermal resistance between the gas turbine liquid fuel system components and one of the primary heat sources, thus providing a reduction in heat transfer into the fuel component that leads to increased operational performance of those components.
In the exemplary embodiment, the thermal isolation device includes an assembly of three thin, flat cylindrical columns and three plates. The columns provide structural support for the isolation device and the liquid fuel system components that are attached to the isolation device. The flat plates, arranged substantially perpendicularly to the columns and spaced from each other along the axes of the columns, provide desired surface area for convective cooling. The three plates are spaced equidistantly from one another, and the number of plates may vary. The device is adapted for integration with a gas turbine combustor assembly, for example, between the combustor end cover and the liquid fuel distributor valve.
The height of the isolation device is sized to provide adequate increase in conductive path length for increased thermal resistance. The plates are sized to be as large as possible so as to provide maximum surface area for cooling as well as to provide the maximum shielding of radiation heat loading from the end cover to the liquid fuel distributor valve, while being limited by geometric restrictions due to adjacent componentry on the current combustion end cover assembly and the limitations of additional structural concerns due to vibration.
Accordingly, in one aspect, the present invention relates to a thermal isolation device for a gas turbine combustor assembly comprising a plurality of substantially flat plates secured in spaced relationship by a plurality of columns, at least one column incorporating a bolt hole for use in securing the device between a pair of combustor components.
In another aspect, the invention relates to a thermal isolation device for a gas turbine combustor assembly comprising at least three substantially flat and substantially triangular-shaped plates secured in spaced, substantially parallel relationship to at least three columns.
The invention will now be described in connection with the drawings identified below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a thermal isolation device in accordance with an exemplary embodiment of the invention;
FIG. 2 is a plan view of the device shown in FIG. 1 ;
FIG. 3 is a section taken along the line 3 – 3 of FIG. 2 ; and
FIG. 4 is an enlarged detail taken from FIG. 3 ; and
FIG. 5 is a perspective view of the thermal isolation device as shown in FIG. 1 in combination with a liquid fuel distributor valve.
DETAILED DESCRIPTION OF THE INVENTION
With reference initially to FIGS. 1–3 , the thermal isolation device 10 is constructed of three discrete columns 12 , 14 and 16 , each formed with respective through holes (or bolt holes) 18 , 20 and 22 . A plurality of flat plates 24 , 26 and 28 are secured to the columns in axially spaced relationship, i.e., axially spaced along the longitudinal axes of the columns.
The three cooling plates 24 , 26 and 28 are approximately 0.100 inches in thickness, and their plan view geometry is approximately triangular, with truncated corners at 30 , 32 . The cooling plates 24 , 26 and 28 generate a maximum footprint or coverage on the end cover, limited only by structural vibration concerns.
The plates 24 , 26 and 28 are secured, by brazing for example, to respective radial flanges 34 , 36 and 38 , best seen in FIG. 4 . The diameters of the flanges increase from top to bottom (in the orientation shown in FIGS. 3 and 4 ) facilitating brazing of the plates to the columns.
The length or height of the columns 12 , 14 and 16 is determined so as to provide increased conduction length and hence less heat transfer into the liquid fuel distributor valve 40 from the combustion end cover 42 . In the exemplary embodiment, the thermal isolation device 10 , including the columns and plates, is made of stainless steel.
The columns 12 , 14 and 16 are arranged so as to accommodate the mounting flange and bolt pattern of the liquid fuel component parts. In the exemplary embodiment, the component parts include a liquid fuel distributor valve 40 best seen in FIG. 5 . In this way, the device 10 can be mounted between the mounting flange 44 of the liquid fuel distributor valve 40 and the combustion end cover 42 and secured by bolts 46 , 48 and 50 without modification to either of the fuel component parts. With this arrangement, the large planform area of the thermal isolation device 10 provides shielding of radiation modes from the end cover 42 . At the same time, cooling air flowing between the plates 24 , 26 and 28 at temperatures of 250–275 ° F. will provide a cooling benefit to the liquid fuel distributor valve 40 and the fuel flowing through the valve. It is expected that the fuel temperature may drop by about 50° F.
It will be appreciated that the triangular shape of the plates is dictated to a large extent by the shape of the mounting flange or other surface of the fuel component to which it is to be attached and its associated bolt pattern. Both the shape and number of plates may vary, depending on specific applications. For example, for a square mounting flange on a distributor valve with a four bolt pattern, the device 10 could be modified to include square plates and four columns arranged to match the four bolt pattern.
The main advantage of a thermal isolation device 10 is an increase in thermal resistance resulting in a sufficient reduction and operational temperatures of the liquid fuel distributor valve so as to lower the liquid fuel temperature and thus result in higher operational efficiency. The isolation device 10 is designed to be an addition to a current system, but requires only minimal changes to the existing components such as fuel tubes, etc.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
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A thermal isolation device for a gas turbine combustor assembly includes a plurality of substantially flat plates secured in spaced relationship by a plurality of columns, at least one column incorporating a bolt hole for use in securing the device between a pair of combustor components.
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BACKGROUND
The field is that of medical instruments, including instruments for direct patient care at home, for laboratory use, and for clinical or hospital use in conjunction with patient care.
Patients and operators of medical machines and instruments may be under a good deal of stress, caused by health concerns and the need for using the medical instruments. These may include dialysis machines, blood separators, sample preparation machines, drug dose preparation devices, and so forth. The stress may be exacerbated by the need for close proximity to the machine for hours on end, such as an overnight peritoneal dialysis procedure. The constant noise made by such machines may be very aggravating and annoying to patients who must remain connected to the machine for hours on end. Other medical instruments that reside in close quarters with operating personnel, such as laboratory sample preparation machines with centrifuges, may also emit annoying sounds.
One way to avoid these sounds is to enclose the medical device or instrument in a separate room or enclosure. This will isolate the annoying sounds from the patient or user. However, some machines, such as blood separators or dialysis machines are better used with short runs of tubing to the patient, and separate enclosures may not be practical. Another way is to provide a separate sound system to generate masking sounds or to play music. This method, however, would require a separate sound system for each medical device, and would be both expensive and cumbersome.
Some medical instruments have artifacts by which they generate their own “masking sounds.” For example, a compressor that operates a dialysis system generates a constant hum that masks other sounds from the instrument, such as the venting of air or the clicking of valves. While the hum itself is not annoying, the hum will change pitch depending on its load and also depending on the portion of the dialysis cycle. This change in pitch, sometimes also accompanied by a change in volume, is noticeable to the patient. Other techniques in general use include efforts to reduce overall machine noise. When a particular noise is eliminated, however, other noises may then become apparent. An example is using a housing or baffles to enclose and silence the above-mentioned compressor. Once the compressor is silenced, the clicking of the valves, the creaking of the dialysis door assembly, and even the swishing of fluid within the dialysis disposable portion become relatively louder and more noticeable.
What is needed is a way to reduce or mask noise of medical instruments so that the instrument is less noticeable to a user or an operator of the instrument. The method used should not interfere with operation of the machine, should be economical, and not require any further separation of the medical instrument from the patient or user. It would also be desirable if the method could be retrofitted onto existing medical instruments.
SUMMARY
One embodiment is a medical instrument. The embodiment includes a medical instrument for patient care, laboratory use, or pharmaceutical use, a computer, the computer forming a part of the medical instrument and configured for controlling and operating the medical instrument. The embodiment also includes a sound capability comprising a sound card within the computer or the sound capability forming a portion of the computer, a speaker for generating sounds from the sound capability, and a control panel for selecting the sounds, wherein the medical instrument generates a plurality of undesirable noises and wherein the computer, the control panel, the sound capability and the speaker are configured for processing digital files and to generate music or sounds to mask the noises or to mask perception of the noises, and optionally to allow a user or operator of the medical instrument to select the music or sounds.
Another embodiment is a medical instrument. The medical instrument includes a medical instrument for patient care, laboratory use, or pharmaceutical use, and also includes a computer, the computer forming a part of the medical instrument. The medical instrument also includes a sound card connected within the computer or a sound capability forming part of the computer, a speaker for generating sounds from the sound card, and a control panel for selecting sounds and adjusting a volume of the speaker, wherein the computer, the control panel, and the sound card or sound capability are configured for generating a plurality of sounds from a digital file and are configured to optionally allow a user or operator of the medical instrument to select the sounds to mask noises from the medical instrument.
Another embodiment is a medical instrument, the medical instrument selected from the group consisting of a blood separation machine, a peritoneal dialysis machine, a hemodialysis machine, an automated drug preparation machine, an automated sample preparation machine, and a machine for pumping or mixing medical fluids. The medical instrument also includes a computer, the computer forming a part of the medical instrument and configured for operating and controlling the medical instrument, a sound card operably connected to the computer or a sound capability forming part of the computer, a speaker for generating sounds from the sound card or sound capability, a control panel for selecting sounds and adjusting a volume of the speaker, wherein the sound card or sound capability is configured for generating a plurality of sounds from a digital file and wherein the computer, control panel, sound card or sound capability, and the speaker are configured for optionally allowing a user or operator of the medical instrument to select and generate sounds from the digital file to mask noises from the medical instrument.
Another embodiment is a method for masking noises from a medical instrument. The method includes selecting a medical instrument that makes undesirable noises, operating and controlling the medical instrument with a computer having an internal sound capability and a speaker, selecting at least one digital file for masking the undesirable noises, the medical instrument optionally programmed for making a default selection, and playing the sound using the internal sound capability and the speaker, wherein noises from the medical instrument are at least partially masked by sounds from the internal sound capability and the speaker.
Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a chart depicting one test of consumer preferences for methods of masking noise;
FIG. 2 is a schematic diagram of a first embodiment of a medical instrument that generates masking sounds;
FIG. 3 is a schematic diagram of a portion of a medical instrument that generates undesirable noise;
FIG. 4 is a schematic diagram of a sound card useful in embodiments;
FIG. 5 is a schematic diagram of a motherboard with a built-in sound capability useful in embodiments;
FIG. 6 is a schematic diagram of an external sound controller that may be used in embodiments;
FIGS. 7-8 are graphs of desired distributions of sound pressure (noise) levels at frequencies of human hearing;
FIGS. 9-10 are flowcharts for methods of using masking sounds or music to provide a more comfortable environment for patients or users;
FIG. 11 depicts another embodiment of a signal processing for improving the masking of medical instruments.
DETAILED DESCRIPTION
Embodiments of the present invention may form part of a medical instrument. Any device that generates undesirable noise will receive the most attention when it is used or operated over a period of time in close proximity to an operator or user of the device. Thus, if a noisy testing machine or compressor can be located far away in a sound-proof room, it will not generate its noise near people and thus will not draw complaints. Many machines, including medical instruments, must operate in close proximity to one or more people for one reason or another. If these machines or instruments are used in close proximity for a longer period of time, perhaps hours, the person or persons in close proximity will see the need for a measure of noise control.
There are many ways to conceal or disguise the noise coming from such a machine. Of course, a first option is to do nothing to reduce the noise from the machine. The users or operators may be left to fend for themselves, and could presumably use self-help techniques, such as ear-plugs, or perhaps a personal device, such as a portable radio, CD, or MP3 or other player, preferably with ear buds or headphones. A minimal step to assist in patient comfort would be to add muffling or baffles within the machine to reduce the overall level or noise. Another step would be to add noise, e.g., a pleasing sound that would drown out annoying noise made by an mechanical component. Another example would be to run continuously a noise that otherwise would cycle on and off, perhaps in an unpleasant or screeching manner. Of course, one could do both of these latter steps, i.e., an overall noise reduction or baffling effort combined with certain added noises to make the overall experience more pleasing to the patient. The inventors have now added another option, adding a level of digitally-generated noise to reduce perception of at least some of more objectionable noises emanating from the medical instrument. This may also be combined with a reduction in the amount of noise generated by the instrument.
A consumer preference test was conducted among 17 dialysis patients and 57 employees of the assignee of the present patent to see which method would be preferred. The test was thus conducted among 74 panelists divided into two panels. The first panel tests were conducted in Waukegan, Ill., in October, 2006, and a second panel in Pinellas Park, Fla., also in October, 2006. Panelists were asked to listen to various types of machine noises, consisting of existing and prototype instruments, as well as digitally modified sounds. Various sample noises were presented that employed noise reduction techniques as discussed above. The data obtained from the panelists ranked the sounds in order of preference.
The normalized results of the survey are depicted in FIG. 1 . Reduced noise levels were strongly preferred, with either mechanical masking or digital noise added. Most preferred was an overall reduction in machine noise combined with digital noise masking. The digital sounds that were added included “white noise,” as well as the extracted mechanical masking noises from actual instruments. The perceptions and preferences of the panelists were consistent with each other, with no significant difference in the rankings of the sounds between the employee and patient groups. Based on these tests, the inventors concluded that people who use dialysis machines would appreciate an improved medical instrument with masking sounds to reduce the perception of noise generated by the dialysis machine. The inventors also concluded that this concept could be extended to other medical instruments and devices with high noise levels and close contact with the people who operate them or use them.
An example of such an instrument is disclosed in FIG. 2 . Medical instrument 10 may be any medical instrument that generates undesirable noise. If the medical instrument is a dialysis device, such as a peritoneal or hemodialysis device, it may generate noise such as the hum from the constant pumping or compressing of air. A sporadic clicking noise may be generated by opening and closing pneumatic valves. A hissing noise may be generated from the inflow of air to the pump or compressor, and a rush may be generated from the exhaust of air from the instrument.
Medical instrument 10 includes an operating portion 11 , including fluid lines 12 for connection to a patient. An operating section 11 may perform a dialysis or other function for the patient under the supervision of a control section or computer 13 . Computer 13 will preferably have at least an input keypad 14 , control panel 14 a , which may be a touch screen, input number pad 14 b , and mouse 14 c . The computer will also include input drive 15 a , which may be suitable for a floppy drive or for a CD drive. The computer will preferably be configured with a port for Internet access 15 b , as well as additional inputs and outputs, including ports 16 . The additional input ports may be any combination of serial ports, such as USB ports, or parallel ports. In some embodiments, the computer will be adapted to receive commands from a remote control unit, and will include an IR receiver 15 c for a hand-held remote. Inputs/outputs may include an optical input or output 15 d and other digital or analog inputs. Control portion 15 e includes a series of controls knobs or switches for adjusting sound level output by frequency. There is preferably an overall volume control 15 f . In order to mask noises made by the medical instrument, the instrument now includes at least one speaker 17 a (or headphones 17 b or earbuds 17 c ) and preferably also includes a microphone 18 , and an antenna 19 for receiving at least remote commands or information. The antenna may be used for wireless (WiFi) internet access or may be used for remote, but closer, commands.
In operation, the medical instrument, such as a dialysis instrument, is connected to a patient for a procedure, such as a dialysis treatment. When the machine is activated, the annoying sounds begin. The machine may automatically begin to play music or a masking noise, or an operator or user may enter a command to activate the music or masking noise. The command will be entered through the keypad, a keyboard, the control panel of the computer, or from a remote control unit. The computer will begin to play a digital sound or music file that has been entered into the computer. The music may be any music that is pleasing to the patient or to the clinic or hospital operating the medical instrument. If a masking sound is preferred, white noise or pink noise (less high frequency content) may be used. Other types of shaped random noise may be specifically engineered to effectively mask particular instrument sounds, and would be included as appropriate for that device. Other sounds may include soothing environmental sounds, such as water sounds, wind sounds or others. Such sounds typically have a theme, even a repetitive theme, but with sufficient variation that the sounds are both interesting and soothing. A variety of recordings of such sounds, including air conditioner hums, air purifier noise, fan or dryer noise, rainfall, running water, babbling brook, ocean wave sounds, and so forth, are available from PureWhiteNoise.com, Tallahassee, Fla., USA.
The computer will preferably have a sufficient variety of music or sound files to last for at least as long as the period of treatment. It should allow for looping of sounds or music playlists, or for setting a specific sequence of sounds for the course of the therapy. The computer should also have sufficient variety so that the same recording(s) are not repeated every time the patient returns for treatment. Besides environmental sounds, music may also be used. Music is available from a variety of sources, and a patient may even have his or her own copies of preferred music, so the ability to upload new content to the instrument is desired.
In addition to one or more speakers, which may be integral with the computer or the medical instrument, or may be separate, it is preferable, but not necessary, to use a microphone in embodiments described herein. The microphone may be used to detect sound levels and frequencies resulting from operation of the medical instrument and from playing the masking noise or music. The user or operator of the medical instrument may prefer to adjust the volume of the masking sounds simply by ear. Alternately, the user may program the computer to adjust the sound level based on the noises made by the medical instrument.
If the computer is programmed to adjust sound levels based on the noise generated by the medical portion of the instrument, the programmer should be careful to avoid any “siren” effect. A siren effect is a monotonous rise and fall of frequency, and typically volume, mimicking the noise made by an ambulance or police car. This is not a soothing sound, and may be avoided by selecting a constant noise or by damping variations in the sound. For instance, a program for moderating the masking noise may use a threshold volume of 50% or 75% of the maximum volume of the annoying noises, and may also use a faster reaction for increasing volume than for lowering volume. That is, the masking sounds or music may vary, but will not lower the volume sufficiently so that the annoying sounds are heard. In addition to “siren” effect changes in frequency, other transient noises that arise during the operation of the instrument may need to be obscured or masked. Masking sounds may be pre-programmed to change as needed prior to, or coincident with, such transients. Control algorithms may additionally respond in real time to detect deviations in noise.
Medical Instruments
The medical instrument which requires masking noises or sounds may be any of a great variety of medical instruments or machines. One example of a pneumatic portion of a renal care machine that requires masking is depicted in FIG. 3 . Peritoneal dialysis (PD) machine 20 typically includes a compressor or pump 21 c for compressing air to operate the dialysis machine 25 . The pump may also be used to pump air from a tank 23 , creating a partial vacuum. Noises include those made by the pump 21 c , its motor 21 d , and noises from each valve in the system, as well as the rush of incoming air from an ambient air intake 21 a , which may be muffled, and the exhaust of air, preferably into a sound enclosure 21 b . The noise from the pump generally depends on the pressure differential being generated by the pump, and can be very noisy at a high pressure differential, such as 7 psid. Of course, the noise level also depends on the flow rate of the air, with higher flow rates generating higher noise levels. Enclosures help to suppress the sounds of the air flows and the compressor or pump noises, much as a muffler helps to minimize the noise of a car engine. These measures are effective, but by analogy, when a person must sit beside a quiet machine for hours, even these muffled noises will become annoying.
Other noises will include clicks or bangs as three-way inlet valves 22 open or close to admit compressed air into the positive pressure air tank 24 or to admit small amounts of pressurized air into the PD machine 25 . Noises will also be generated by operating valves 26 to admit air to or from vacuum tank 23 or to exhaust the air, preferably into a sound enclosure 21 b . A baffle or orifice 27 in the exhaust line will create a back pressure when three-way outlet valve(s) 26 open to exhaust air from the PD machine. This will minimize the noise of the air rushing through the lines, with minimal effect on the timing of the internal workings of the PD machine. Restrictive baffles or orifices may be placed at other points in the air path to create a back pressure, enabling the system to pump at a constant, if higher, pressure and generate less noise. As noted, this can be minimized by exhausting into a muffled enclosure 21 b . In addition to in-line muffling technologies, enclosing subsystems in sound reducing enclosure can help to reduce noise levels.
The task of masking noises from the machine described above is made difficult because the machine itself, like most medical machines or instruments, is already highly-engineered. The components and subsystems of the machine have typically been made as quiet as possible, and steps taken to reduce noise at their source. Sound absorbing and reflecting materials are used in conjunction with enclosures and baffles, as discussed above, to trap and dissipate sound energy. The machine may even use control schemes and algorithms to reduce noticeable and offensive transient noises, with special attention paid to the intake and exhaust systems. Manufacturers are aware of the need to enhance the quality of life for the patients using their machines. Obvious steps, such as minimizing air noise, will likely have already been taken. The air pressure differentials may be low, e.g., about 4-5 psi (about 40-50 kPa) above atmospheric for the positive pressure air tank, and about 4-5 psi (about 40-50 kPa) below atmospheric for the “vacuum” tank. Thus, when air is compressed, stored, used and exhausted, the quantities and pressures are minimal, even when compared to pressures used to inflate a tire (30-35 psig, about 205-240 kPa).
At the pressures used in the medical instrument, the obvious noises are likely already minimized, and further improvements in one area, e.g., quieting the pump, may simply make other noises more obvious, e.g., the rush of the air or the clicking of the valves. As pointed out, masking the noises, rather than further noise reduction, may be the more desirable option.
A variety of other medical instruments may benefit from the use of masking noises or music. For example, blood separation machines are used to separate red blood cells from whole blood of volunteers. The donated red blood cells are then used to treat victims of trauma, persons with certain types of cancer, or persons with sickle cell anemia. An example is the Alyx centrifugal blood separation machine made by Fenwal, Inc., of Round Lake, Ill., USA. This machine includes pumps, clamps and valves that move the volunteer's blood through the machine. Blood separators are typically found in municipal or regional blood centers. Even though a patient is typically connected to the machine for less than one-half hour, the blood separator would benefit from soothing music or distracting white noise to mask the sound of the centrifugal whirring, the clicking of the valves, and the hiccupping sound of the clamps opening and closing. The beneficial effects would also be noticed by the nurses supervising the volunteers, who are in contact all day with the separator.
There are many other examples. For instance, many laboratories or preparation facilities use centrifugal machines or mixers for to prepare samples for analysis. Other machines are used to prepare doses of a medicine for immediate consumption. Such machines are made by PerkinElmer Life and Analytical Systems, Inc., Shelton, Conn., USA and Parata Systems, Inc., of Durham, N.C., USA, among others. While not meaning to specifically point out these manufacturers or their machines, they may be typical of medical instruments or devices that generate noise. They may benefit, among many others, from a noise masking system that is used with and controlled by the machine itself.
Hardware to Generate Music or Masking Sounds
The hardware used to play the masking sounds or music may include any of the devices depicted in FIGS. 4-6 . The options for the computer typically include, but are not limited to, a sound card, a sound capability built into the computer motherboard, or an external sound control. These are options that may be used, but any other suitable hardware may be used instead or in addition to these. As shown in FIG. 4 , a sound card 30 is typically mounted on a printed circuit board (PCB) and includes digital signal processor (DSP) 31 and a memory 32 , along with its own microprocessor computer 33 , a digital to analog converter (DAC) 34 , an analog to digital converter (ADC) 35 , and a PCI (peripheral component) interface 35 to the instrument computer. Some embodiments use a coder/decoder (codec) chip 36 to perform the functions of the ADC and DAC converters. The sound card also includes numerous input/output lines 38 , at least for connection to the instrument computer and one or more speakers, such as output 37 . It is possible that the user may desire to send the output to a separate player, such as a digital audio player, also known as a DAT player. It is desirable to include an input connection for a microphone or an output connection for headphones. Sound cards are available from many manufacturers and typically have excellent performance. If a medical instrument or device can accept and utilize a sound card, this would be a preferred way to adapt the instrument.
Rather than adding a separate sound card, a computer may be equipped with an integral sound capability residing it its motherboard or other circuitry, as shown in FIG. 5 . Circuit board 40 may include a central microprocessor controller computer 44 , and numerous other hardware for storing and reading digital files and generating music or sound. These include a digital signal processor 41 , a digital to analog converter 42 , an analog to digital converter 43 , a memory chip 45 , and optionally, a codec chip (not shown). The board will have numerous input/output lines 46 , preferably including separate outputs 47 for one or more speakers and an inlet line 48 for a microphone. In order to use this option, the medical instrument or device would likely be designed from the start to include the sound capability. Alternatively, the system might require extensive modification to add such a sound capability.
Another hardware option is to add an external sound capability to the computer that operates the medical instrument. An external sound control includes all the components discussed above that are necessary to read a digital file and play music or sound from the file. External sound controls, such as “Sound Blaster,” are available from Creative Labs of Milpitas, Calif., USA. External sound controls are also available from Griffin Technology, Nashville, Tenn., USA. As shown in FIG. 6 , the external sound controller 50 may include controls 51 , 52 , such as for volume and frequency mix (bass/treble). The sound controller includes numerous input/output lines 53 , and preferably includes separate lines 54 for output speakers 54 and for a microphone 55 . External sound controls may also include a remote capability, using a remote window 56 . An audio output 57 for headphones or earbuds may also be used.
It is possible to use other players to input digital files, such as a mini-disc player using an optical medium (e.g. a Sony MD Walkman) or an MP3 player (such as an MP3 Walkman or an Apple iPod), or other devices, such as standard CD players. It is also possible to output converted files to a separate player, such as an optical output to a mini-disc player or a DAT player, rather than to the usual speaker(s) or headphones. Not shown are the internal components, which are typically similar to those used for sound cards and an integral sound capability, such as a microprocessor, a digital signal processor, memory, an ADC, a DAC, and so forth. If an existing medical instrument or device cannot accommodate a sound card, it may be simpler to connect an external sound capability.
Methods for Using Masking Sounds and Music
Embodiments may use the hardware described above, and the medical instrument or device may also include programming to insure satisfactory performance. It has been found that the frequency distribution of noise, such as white noise, can have a profound effect on the sound pressure levels necessary to achieve masking that is not unduly annoying. One example is U.S. Pat. Appl. Publ. 2003/0144847, published on Jul. 31, 2003, and which is incorporated herein by reference in its entirety, as though each word and drawing were appended hereto. This publication teaches the effectiveness of masking noise with a frequency having a substantially constant negative slope over the frequency range of the human voice, from about 200 Hz to about 5000 Hz. The slope is desirably about −4 db per octave, and may be between about −2 to −6 db per octave. With this distribution, the overall dB level of masking sounds needed to mask at least voices is significantly reduced. More generally, masking sounds should have a spectrum that is a close match to the spectrum of noise that is to be masked. Embodiments of the present invention, however, are not limited to these ranges.
Accordingly, when the frequency and sound pressure (noise) levels of a medical instrument are documented, the masking noise or music may be tailored so that the sound pressure level or decibel level of the music or noise may be used to just exceed the dB level of the medical instrument. The tailoring or variation in the masking noise, however, should not be so abrupt that it rises to the level of a “siren” effect, which is typically much more annoying than normal instrument or machine noises. Of course, masking sounds should be used primarily in the range of human hearing capability, from about 20 Hz to about 20 kHz (20,000 Hz). A table of the octaves used in studying hearing is listed in Table 1.
TABLE 1
Octave Band
Frequency Range, Hz
Central Frequency
1
20-40
30
2
40-80
60
3
80-160
120
4
160-320
240
5
320-640
480
6
640-1280
960
7
1280-2560
1920
8
2560-5120
3840
9
5120-10,240
7680
10
10,240-20,480
15,360
Source: EURASIP Journal on Applied Signal Processing 2005: 18 3015-3025, “A Low Power Two-Digit Multi-Dimensional Logarithmic Number System Filterbank Architecture for a Digital Hearing Aid,” by Roberto Muscedere, Vassil Dimitrov, Graham Jullien and William Miller, Research Center for Integrated Microsystems (RCIM), University of Windsor, ON, Canada.
The masking noise will desirably have a frequency distribution with a substantially constant negative slope from about −2 to about −6 dB per octave, preferably about −4 dB per octave, as noted. An example is depicted in FIG. 7 , with a slope of −4 dB per octave. Error bars on the vertical axis are set for ±2 dB, to demonstrate the preferred range of slope. Low frequency machine noises, especially those at the 60 Hz and its harmonics, 120 Hz, 180 Hz, and so forth, will be very noticeable to persons close by. However, if they are distracted by noise at higher frequencies, but not at higher sound pressure levels (dBs), the absolute level of the noise needed to mask the medical instrument may be lower than otherwise expected. Typical noise criteria curves will drop off more steeply at lower frequencies, generating less sound at low frequencies, and will drop off less steeply at higher frequencies, generating more sound than may be necessary. It appears that it is more important that the slope of the distribution is constant, rather than the precise value of the slope, within these limits. This will help to minimize the total level of sounds needed to mask the noise of the medical machine. FIG. 8 depicts frequency and noise levels at constant slopes of −2, −4 and −6 dB, with −2 dB being the flattest curve while −6 dB has most dramatic sound level drop-off.
Audio playback equipment may include a graphic analyzer or equalizer, or less frequently, a parametric equalizer. This equipment may be used in accordance with the principles discussed above to tailor the playback for greater filtering or cut-off at progressively higher frequency bands. Some equipment uses only 5 frequency bands for the entire audio range, while others use at least octaves, and will have 9 or 10 bands, each of which may be assigned a dB value for amplification or attenuation. As discussed, a substantially constant slope of −4 dB octave is preferred. Some equipment may have bands for each ½ octave, so that 18 to 20 bands (and settings) are possible, while the best equipment has bands for each ⅓ octave, with 30 or 31 bands and settings possible.
A particular digital file may be analyzed and settings on a graphic equalizer, or preferably a parametric equalizer, may be optimized for maximum masking effect. The settings may be chosen on the basis of consumer preference, analysis of feedback from executing the file, or simply entering settings corresponding to a desired slope of amplitude or volume versus frequency. It should be noted that this procedure amounts primarily to shaping and filtering a particular signal, and does not affect the signal file (recording) itself. For instance, if the digital file has very low volume or amplitude at low frequencies (bass), 5 to 10 decibels of amplification at that frequency may not be sufficient to achieve the desired optimal output sound level at that frequency, and it may be necessary to boost the amplification at that or surrounding frequencies. In a similar manner, if the high frequencies (treble) have very high volume or sound level, a few decibels of attenuation may not be sufficient to lower the sound level to match that area of the preferred slope. Particular recordings or digital files may require different adjustments. Ultimately, user or operator perception of masking should decide the particular settings and output volume of the masking equipment.
Embodiments include methods of using sounds and music to mask the noises made by medical instruments and machines. Two methods of the many methods possible are depicted in FIGS. 9-10 . A first step 81 is to measure absolute noise levels of the instruments in question. This step may be avoided and a measure of the output sound taken “by ear” for comparison, but overall noise and music levels may be minimized by careful attention to feedback from such details. It is clearly desirable, but not absolutely necessary, to obtain an analysis of the frequency and sound pressure level distribution of the instrument before beginning. A masking sound or music selection may then optionally be made 82 . A test run may then be made, playing 83 the sound or music, and measuring the level of sound or music against the instrument or machine noise, preferably in several portions of the frequency spectrum. The test may be run with sound-measuring instruments, or may be run with a test panel of persons.
After the first test is run, and using feedback from the first test, the level of masking sound or music may be adjusted 84 and again compared 85 with instrument noise for absolute noise level comparison or for comparison by human perception. The sound or music may then be adjusted if necessary 86 . The testing should include a check 87 that the generated masking sounds do not yield a siren effect, or other objectionable effects or sounds from a sound-quality perspective. For example, checks on sound roughness, amplitude modulation, and so forth, may also be used to ensure that sounds generated are pleasing and soothing to the patients or users of the devices. The program for generating masking sounds of music may be concluded 88 when the particular procedure is completed. Other methods of masking sounds may also be used.
In another embodiment, the equipment used to generate masking sounds may be programmed to keep the slope of the frequency/sound level distribution, as discussed above, to a substantially constant negative slope, preferably −4 dB per octave, but also possibly including slopes from −2 to −6 dB per octave. This embodiment uses a method similar to that discussed above for FIG. 9 , but also paying attention to the slope. It is easier to follow this method when using generated noise, such as white noise or pink noise, or soothing environmental sounds as discussed above, rather than recorded music. The method of FIG. 10 includes using a substantially constant slope of a frequency/sound pressure level logarithmic graph. The first step 91 is to measure the sound level of noises generated by the medical instrument, over the appropriate frequency range. Appropriate masking sounds or music, preferably having a frequency profile with the potential to mask the machine noise, are then optionally selected 92 .
The masking sound or music is then played and the sound levels over the frequency range are measured and compared 93 to the machine noise. The level of the masking noise or music is then adjusted 94 for a substantially constant slope of sound level versus frequency. The test may then be run again, checking the altered sound levels 95 at frequency to see if the machine noises are indeed masked. The comparison is preferably accomplished with both technical data and consumer perception. Any adjustments, such as the output for a particular frequency range, may then be made 96 , with particular emphasis put on the constant slope of the curve. When this has been accomplished, a test may be run 97 to insure that any siren effect is not noticeable. The masking program may then be concluded 98 when the medical, laboratory, and clinical procedure has been accomplished.
The appropriate sound level distribution over frequencies may be achieved with an apparatus as described in FIG. 11 . A signal processor 100 is preferably a sound card, with a DSP 100 a , a DAC 100 b , an ADC 100 c and memory 100 d . A PCI interface (not shown) may also be desirable. The digital signals from a digital music or sound file are sent to a sound mixer 101 , where the signals are segregated into octaves, of more preferably ½ octave bands, or even more preferably into ⅓ octave bands and then sent to a series of filters or “equalizers” 103 . In one embodiment, there may be 10 “equalizers,” or sound level adjusters, for the 10 octave bands. In other embodiments, there may be about numerous ½ octave bands or even more numerous ⅓ octave sound level adjusters, such as 28 to 31 bands and filters.
In this instance, the “equalizers” are not used merely to equalize the output sound levels, but rather to apply a bias to the frequency distribution, as discussed above. The equalizers are thus used as sound level output adjusters that adjust the slope of the sound level/frequency distribution. The slope should be substantially constant and should be from about −2 dB per octave to about −6 dB per octave. Other output slopes may also be used, however. The outputs of the filters are then combined into output 105 . The outputs are preferably analog outputs to be sent to the speaker(s) of the masking system. The outputs could be digital outputs and could be sent to an amplifier, if necessary, if the noise levels require, before being played through a speaker, but this should not be necessary for a single medical instrument. Adjusting the dB levels of the filters or “equalizers” allows a user or operator to select the sounds output by the medical instrument.
The equalizers may also be used to specify changes in overall sound level, dB per frequency or frequency band, and adjustments to the nature or dimension of the sound with respect to parameters of sound perception. These dimensions may include sharpness, roughness, modulation, or any other desired measure of sound quality. In some embodiments, operators and users may select which particular sounds or music to play. In other embodiments, the medical instrument may be programmed in advance to play one or more tracks or recordings, or to mix tracks or recordings in a pre-set or random manner.
It is also possible to simultaneously use more than one sound track or digital file to generate masking sounds. The files may be mixed and played at selected volumes, perhaps a higher level of a white noise file and a lower level of a soothing environmental sound, such as ocean wave noises. Such techniques are well known and are described in U.S. Pat. Appl. Publ. 2003/0144847, discussed above. Other techniques may also be used. For instance, a music file or file that generates soothing sounds may be played and filtered or biased so that the output sound level decreases with frequency as discussed above. This recording may be done on-line and used, or may be created off-line and then stored in the medical instrument computer or memory for later use. Recordings with higher levels of sound output at frequencies at which the medical instrument generates noise may also be created and recorded for future use. Finally, the computer may be programmed to change recordings or files periodically, perhaps with gradual transitions, so that a variety of music or sounds is used, including silence or a turnoff after one or two hours. In some applications, such as overnight dialysis, the user may prefer to go to sleep with a little help from masking sounds or music. In other applications, such as a half-hour blood donation/separation, or a several hour day-time dialysis, a more lively and interesting variation in music may make the time pass more easily.
It should be understood that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
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A medical instrument includes a sound card or an internal capability for generating sounds from a digital music or sound file. The medical instrument is one which generates unwanted noise and is constantly in the presence of a patient or an operator, and may be in a home, a clinic, a laboratory, or other intimate setting. For instance, a patient may be typically connected for hours to a hemodialysis machine that has a noisy pump. A blood-plasma volunteer may be hooked to a noisy blood separation machine for a period of time. A laboratory technician may work in close proximity to a sample preparation machine that constantly gurgles and whirrs. In each instance, a sound card and a speaker can generate previously-recorded masking noises that make that the presence and operation of the machine more tolerable.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Continuation of U.S. patent application Ser. No. 09/948,972, filed Sep. 7, 2001, which claims the benefit of U.S. Provisional 60/235,620, filed Sep. 27, 2000, the contents of which are entirely incorporated herein by reference.
SEQUENCE LISTING
[0002] Incorporated herein by reference is a text file containing an Amended Sequence Listing, file name, 547 — 1_CON_SEQLIST.TEXT, created on Dec. 22, 2008, file size of 956 KB.
FIELD OF THE INVENTION
[0003] This invention relates to assays and reagents for measuring protein kinase activity in vitro.
BACKGROUND OF THE ART
[0004] Drug development efforts involve a continuum of activities initiated by target selection of a molecule. Since all drugs work at the level of the cell, those targets are usually proteins that somehow are involved in cellular communication pathways. Signal transduction pathways are key to normal cell function. Aberrations in the expression of intracellular molecules and coordinated interactions of signal transduction pathways are associated with a variety of diseases and, thus, are the focus of drug, discovery efforts. Phosphorylation of proteins in signal transduction pathways is one of the key covalent modifications that occur in multicellular organisms. The enzymes that carry out this modification are the protein kinases, which catalyze the transfer of the phosphate from ATP to tyrosine, serine or threonine residues on protein substrates. Phosphorylation of these amino acid residues can alter the function and/or location of the protein within the cell. This change can involve changes in the enzymatic activity of the affected protein and/or create binding sites for the recruitment of other signaling proteins. Because protein kinases are critical components of many cellular signaling pathways, their catalytic activity is often tightly regulated. Abnormalities in protein kinase activity result in different patterns of phosphorylation that can dramatically alter cell function. Indeed, many drug discovery efforts involve the identification of therapeutic agents that selectively suppress or augment protein kinase activity in order to treat a disease. This invention is designed to provide assays and reagents to monitor protein kinase activity.
[0005] The targeted residues for phosphorylation can be contained in a full-length, biologically active molecule of recombinant or natural origin. Most methods currently employed for measuring protein kinase activity use peptide substrates, which include the targeted phosphorylation residue. This art is taught in U.S. Pat. No. 6,066,462 (Quantitation of individual protein kinase activity) incorporated herein by reference. This method differs from the present invention in that the peptide substrate does not contain all possible phosphorylation sites that can be acted on by kinases and thus may not truly reflect activity on a natural protein. The invention described herein can be used with whole molecule or fragments, of natural or recombinant origin. Also, the delineation of activity at different phosphorylation sites requires in the invention, a different PSSA for detection as opposed to a different peptide in U.S. Pat. No. 6,066,462.
[0006] Another method for detection of kinase activity involves use of a generic antibody that binds to all phospho-tyrosine residues. This method is described in U.S. Pat. No. 5,766,863 (Kinase receptor activation assay) incorporated herein by reference. This method suffers from an inability to discriminate among phosphorylated tyrosine residues on a molecule. This method does not address detection of phospho-serine or phosphothreonine events since the anti-phospho-tyrosine antibody does not detect such phosphorylated residues. In contrast, the method described herein uses antibodies, which bind to the sequence specific residues surrounding the phosphorylated amino acid plus the phospho-residue itself. The reagents used in this invention are capable of detecting phosphorylated threonine, serine or tyrosine molecules.
[0007] The current invention and related methods are applicable to a wide range of signal transduction proteins (see Table I for a partial list). Three examples are illustrated below using important molecular targets of current interest in basic research and disease-oriented pharmaceutical study.
[0008] Currently, neurobiologists are focusing efforts on the proteins in the brain that can be associated with disease. One such protein is called Tau, a neuronal microtubule associated protein found predominantly in axons. The function of Tau is to promote tubulin polymerization and stabilize microtubules, but it also serves to link certain signaling pathways to the cytoskeleton. Tau phosphorylation regulates both normal and pathological functions of this protein. Tau, in its hyper-phosphorylated form, is the major component of paired helical filaments (PHF), the building block of neurofibrillary lesions that are often found in the brains of individuals with Alzheimer's disease (AD). Hyperphosphorylation impairs the microtubule binding function of Tau, resulting in the destabilization of microtubules in AD brains, ultimately leading to neuronal degeneration. Hyperphosphorylated Tau is also found in a range of other central nervous system disorders. Numerous serine/threonine kinases, including GSK-33, PKA, PKC, CDK5, MARK, .INK, p38MAPK and casein kinase II, can phosphorylate Tau.
[0009] Detection of in vitro kinase activity is critical for screening compounds that may be able to inhibit this activity and therefore could be useful in ameliorating various neurodegenerative diseases where Tau phosphorylation is abnormally high. Current efforts exist to identify drugs that might suppress kinase activity towards the Tau protein; however, these methods suffer from poor sensitivity and low specificity. Phosphorylation at individual Serine or Threonine residues within the Tau protein has been shown to correlate with disease. This invention overcomes both of these deficiencies in the described ‘art’.
[0010] U.S. Pat. No. 5,601,985 relates to methods of detecting abnormally phosphory, lated Tau Protein; U.S. Pat. No. 5,843,779 relates to monoclonal antibodies directed against the microtubule-associated protein, Tau, and hybridomas secreting these antibodies; U.S. Pat. No. 5,733,734 relates to methods of screening for Alzheimer's disease or disease associated with the accumulation of paired helical filaments and U.S. Pat. No. 6,066,462 relates to quantitation of individual protein kinase activity. These patents are incorporated herein by reference.
[0011] In addition to the detection of Tau phosphorylation in AD, other models exist to show the general applicability of the currently described format for monitoring protein kinase activity. For the purposes of illustration, we have also designed assays around the intranuclear Retinoblastoma (Rb) protein important in cell cycle regulation and a cell surface receptor molecule (EGFR), which are both described in detail below.
[0012] Retinoblastoma protein (Rb), the tumor suppressor product of the retinoblastoma susceptibility gene, is a 110 kDa protein which plays an important role in regulating cell growth and differentiation. Loss of its function leads to uncontrolled cell growth and tumor development. Mutational inactivation of the Rb gene is found in all retinoblastomas and in a variety of other human malignancies including cancers of breast, lung, colon, prostate, osteosarcomas, soft tissue sarcomas, and leukemia. Central to the role of the Rb protein as a tumor suppressor is the ability of Rb to suppress inappropriate proliferation by arresting cells in the GI phase of the cell cycle. Rb protein exerts its growth suppressive function by binding to transcription factors including E2F-1, PU.1, ATF-2, UBF, Elf-1, and c-Abl. The binding of Rb protein is governed by its phosphorylation state. Hypo- or under-phosphorylated forms of Rb bind and sequester transcription factors, most notably those of the E2F/DP family, inhibiting the transcription of genes required to traverse the 01 to S phase boundary of the cell cycle. This cell cycle inhibitory function is abrogated when Rb undergoes phosphorylation catalyzed by specific complexes of cyclins and cyclin-dependent protein kinases (cdks).
[0013] Rb contains at least 16 consensus serine/threonine phosphorylation sites for cdks, although the significance of all these sites is still unclear. It has been demonstrated that phosphorylation of threonine 821 on Rh is catalyzed by cdk2/complex such as Cyclin E/cdk2 and Cyclin A/cdk2. The phosphorylation of threonine 821 disrupts the interaction of Rb with the proteins containing the sequence LXCXE, where L=leucine, C=cysteinc, E=glutamic acid, and X=any amino acid residue. The dephosphorylation of Rb protein returns Rb to its active, growth suppressive state. Removal of phosphates on Rb appears to be carried out by a multimeric complex of protein phosphatase type 1 (PP I) and noncatalytic regulatory subunits at the completion of mitosis. The quantitation of Rb phosphorylated at specific amino acid residues gives important information regarding the activity of kinases as well as the functional state of the Rb protein itself. For the purposes of illustration, we designed an assay to quantitate the amount of Rb protein that is specifically phosphorylated at threonine 821 using an ELISA format. This assay does not recognize Rb phosphorylated at sites other than [pT 821 ] or when it is in the non-phosphorylated form. Samples can be controlled for Rb content by parallel measurement of total Rb protein.
[0014] WO 01/11367 (Assay of the phosphorylation activity of cyclin/CDK complex on retinoblastoma (RB) protein for identifying compounds which modify this activity) describes a method for detecting kinase activity by ELISA using a synthetic peptide and a monoclonal antibody that recognizes the phosphorylated form of the peptide. The basis of this method is the coating of a solid phase with a synthetic peptide containing the consensus sequence of a region upon which a kinase acts. The peptide is allowed to come in contact with a kinase that allows a specific residue on that peptide to become phosphorylated. The activity of the kinase then is estimated by the binding of the generic monoclonal antibody to the target phosphopeptide. Our invention differs from WO 01/11367 in that it uses a natural protein as the substrate for kinase activity. This feature is superior to the use of peptides since all naturally occurring phosphorylation sites would be present and the protein would be presented in its normal conformation. The use of a single monoclonal antibody recognizing phosphoserine (clone 2B9) also does not allow any discrimination of the many phosphorylation sites that naturally occur on Rb protein. Our use of specific PSSAs allows that distinction as well as the detection of phosphothreonine and phosphotyrosine residues allowing a profile of Rb phosphorylation sites to be constructed.
[0015] As a third example of the utility of this approach, a cell surface receptor was studied and a kinase-dependent ELISA designed. The Epidermal growth factor receptor (EGFR) belongs to the family of receptor tyrosine kinases (RTKs), which regulate cell growth, survival, proliferation and differentiation. EGFR is expressed at full length as a 170 kDa type I transmembrane glycoprotein which consists of an extracellular ligandbinding domain, a single hydrophobic transmembrane region, and an intracellular domain that exhibits tyrosine enzymatic activity and which is involved in signal transduction. Several deletions in the extra- and intracellular domain of the EGFR have been found in a number of tumors. For example, EGFRvill is a 145 kDa protein with a deletion of exons 2-7 in EGFR mRNA. A 100 kDa truncated EGFR without the cytoplasmic domain is observed in the culture supernatant from A431 cells, a human epidermal carcinoma cell line.
[0016] EGFR is activated by binding of a number of ligands such as EGF, transforming growth factor a (TGFα), amphiregulin, betacellulin, heparin binding EGF-like growth factor (HB-EGF) and epiregulin. The binding causes EGFR homo- and heterodimerization and autophosphorylation of multiple tyrosine residues in the cytoplasmic domain, which involves rapid activation of its intrinsic tyrosine kinase activity. Phosphorylation of tyrosine residues in the COOH-terminal tail of the EGFR. serve as binding sites for cytosolic signaling proteins containing Src homology 2 (SH2) domains. Several sites of in vivo phosphorylation have been identified in the EGFR including Tyr 845 , Tyr 992 , Tyr 1068 , Tyr 1086 , and Tyr 1173 . These sites bind and activate a variety of downstream signaling proteins that contain SH2 domains, including growth factor receptor-binding protein 2 (Grb2), Src homology and collagen domain protein (She) and phospholipase C-γ (PLCγ). The binding of these or other signaling proteins to the receptor and/or their phosphorylation results in transmission of subsequent signaling events that culminate in DNA synthesis and cell division.
[0017] Elevated expression and/or amplification of the EGFR have been found in breast, bladder, glioma, colon, lung, squamous cell, head and neck, ovarian, and pancreatic cancers. Selective compounds have been developed that target either the extracellular ligand-binding domain of EGFR or the intracellular tyrosine kinase region, resulting in interference with the signaling pathways that modulate mitogenic and other cancer-promoting responses. These potential anticancer agents include a number of small molecule, tyrosine kinase inhibitors.
SUMMARY OF THE INVENTION
[0018] The invention describes assays and reagents for quantitating phosphorylation of proteins. The method involves subjecting a protein to a protein kinase that will phosphorylate the protein and binding this specific phosphorylated form of the protein with an antibody specific for the amino acid sequence containing the phosphorylated site and detecting the primary antibody bound to the phosphorylated site. The invention includes antibodies useful in practicing the methods of the invention. The invention particularly relates to phosphorylation of Tau, Rb, and EGFR proteins and antibodies specific for the sites of phosphorylation within the Tau, Rb, and EGFR proteins. However, the invention can be applied to all proteins and antibodies that recognize specific phosphorylation sites on these proteins (see Table I).
[0019] In each example system, the targeted protein (Tau, Rb or EGFR) is phosphorylated in vitro or in vivo and the specific phosphorylation event is detected using a highly selective phosphorylation site-specific antibody (PSSA). The appearance or disappearance of the targeted phosphorylation event can be quantified as a percentage of total protein that may be phosphorylated at each site.
[0020] The highly specific nature of the PSSAs allows parallel independent measurement of multiple phosphorylation sites on one protein. Moreover, different kinases can be measured simultaneously by using different PSSAs that selectively target different sites in the protein, thereby providing an avenue for generating phosphorylation site profiles. In contrast to existing methods that quantitate phosphorylated proteins as a diagnostic or prognostic indication of disease, this invention measures protein kinase enzymatic activity that results in the phosphorylation of proteins at a specific sites. This method is also amenable to large-scale ‘High Throughput Screening’ formats currently being used by pharmaceutical and biotech companies to discover new drugs that block specific phosphorylation events.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 illustrates specificity of the Anti-phospho Tau [pS 199 ] in phosphorylation site-specific antibody (PSSA).
[0022] FIG. 2 illustrates Anti-phospho Tau [pS 124 ] PSSA specificity.
[0023] FIGS. 3 a and 3 b illustrate detection of total Tau vs. Tau phosphorylated at the PICA/serine 214 site by ELISA.
[0024] FIG. 4 a - b illustrate detection of Tau phosphorylated at GSK-3β/serine 199/202 ( 4 a ) vs. total Tau ( 4 b ) sites by ELISA.
[0025] FIG. 5 illustrates a dose-response curve generated in an ELISA using the Tau serine 214 PSSA.
[0026] FIG. 6 illustrates the specificity of the Tau PSSAs in an ELISA to detect Tau phosphorylation catalyzed by PKA vs. GSK-3β enzymes.
[0027] FIG. 7 illustrates that multiple GSK-3β phosphorylation sites on Tau can be detected by ELISA using Tau PSSAs.
[0028] FIG. 8 illustrates that a specific inhibitor of PKA activity selectively inhibits the phosphorylation on serine 214 of Tau but does not interfere with GSK enzyme activity as demonstrated using Tau [pS 214 ] and Tau [pS 199 ] PSSAs as detected by ELISA.
[0029] FIG. 9 defines the specificity of the anti-Rb [pT 821 ].
[0030] FIG. 10 shows studies to determine the specificity of the Rb [pT 821 ] ELISA.
[0031] FIG. 11 shows the specificity of the Rb [pT 821 ] ELISA for threonine 821 as determined by peptide competition.
[0032] FIG. 12 shows the application of the Rb [pT 821 ] ELISA in evaluating kinase activity in Jurkat cells were grown in the presence of the kinase inhibitor, staurosporine.
[0033] FIG. 13 illustrates the specificity of the EGFR PSSA [pY 1173 ].
[0034] FIG. 14 shows the specificity of the EGFR [pY 1173 ] ELISA for tyrosine residue 1173 as determined by peptide competition.
[0035] FIG. 15 demonstrates the response curve of phosphorylation of EGFR in A431 cells after treatment with EGF using the EGFR [pY 1173 ] ELISA.
[0036] FIG. 16 shows the application of the EGFR [pY 845 ] ELISA in evaluating kinase activity in A431 cells were grown in the presence of the tyrosine kinase inhibitor, PDI58780.
DETAILED DESCRIPTION OF THE INVENTION
[0037] Tau System: The Tau protein system demonstrates the utility of this invention on a protein that is found both intracellularly and extracellularly in normal and pathological conditions. The Tau protein has multiple phosphorylation sites acted upon by multiple protein kinases. Phosphoserine and phosphotyrosine residues exist. Both mono-phospho and dualphosphoresidues are distinguishable in this model system.
Tau Recombinant Protein: Full length Tau-441 protein is purified recombinant protein derived through cloning of human Tau cDNA and expressed in E. coli . The protein is purified via standard methods. This protein is commercially available from multiple vendors.
Tau pS 199 PSSA: Rabbits were immunized with a chemically synthesized and KLH conjugated phosphopeptide corresponding to the region of the longest isoform of the Tan protein that includes serine 199. The chemically synthesized phosphopeptides (RSGYS (pS) PGSPG) is sequence ID #I. The Tau pS 199 PSSA was purified from rabbit serum by sequential epitope-specific chromatography. The antibody was negatively preadsorbed using a non-phosphopeptide corresponding to the site of phosphorylation to remove antibody that is reactive with non-phosphorylated Tan. The final product was generated by affinity chromatography using the peptide that is phosphorylated at serine 199. This antibody recognizes specifically the Tau protein when phosphorylated on serine 199, as demonstrated by peptide competition analysis in a western blotting assay. Serine 199 is phosphorylated in vitro and in vivo by glycogen synthase kinase-3β (GSK-3β), which is commercially available.
[0038] The specificity of the anti-Tau [pS199] PSSA Tau specificity is shown in FIG. 1 . Cell extracts from African green monkey kidney (CV-1) cells; stably expressing human four repeat tau and a protein phosphatase inhibitor, were resolved by SDS-PAGE on a 10% Tris-glycine gel. The proteins were transferred to nitrocellulose. Membranes were incubated with 0.50 μg/mL anti-phosphoTau [pS 199 ], following prior incubation in the absence (a) or presence of the peptide immunogen (b), or the non-phosphopeptide corresponding to the tau phosphopeptide (c). After washing, membranes were incubated with goat F(ab′) 2 anti-rabbit IgG alkaline phosphatase and bands were detected using the Tropix WesternStar™ detection method. The data in FIG. 1 show that only the phosphopeptide corresponding to this site blocks the antibody signal, illustrating the specificity of the Anti-Tau [pS 199 ] antibody for this phosphorylation site.
[0000] Tan [pS 241 ] PSSA. The procedures for generating this antibody were similar to those described above for the Tau pS 199 PSSA. The chemically synthesized phosphopeptide was derived from the region of the longest isoform of Tau protein that includes serine 214 (GSRSRTP(pS)LPTPP) sequence ID#2. This antibody recognizes specifically the Tau protein when phosphorylated on serine 214 as demonstrated by peptide competition analysis in a western blotting assay. Serine 214 is phosphorylated in vitro and in vivo by cAMP-dependent protein kinase (PICA), which is commercially available from Biosource International.
[0039] Tau pS 214 PSSA specificity is show in FIG. 2 . SF-9 cell extracts, expressing human four repeat tau, were resolved by SDS PAGE on a 10% Tris-glycine gel. The proteins were transferred to nitrocellulose. Membranes were incubated with 0.50 ug/mL. anti-phospho tau [pS 214 ], following prior incubation in the absence (a) or presence of the peptide immunogen (b), or the non-phosphopeptide corresponding to the tau phosphopeptide (c). After washing, membranes were incubated with goat F(ab′) 2 anti-rabbit IgG alkaline phosphatase and bands were detected using the Tropix WesternStar™ method. The data in FIG. 2 show that only the phosphopeptide corresponding to this site blocks the antibody signal, illustrating the specificity of the Anti-Tan [pS 214 ] antibody for this phosphorylation site. PSSAs to other Tau sites [pS 202 , pS 396 , pT 118 , pS 199 /pS 202 , pS 404 ] have been characterized using similar methods.
Pan-Tau Polyclonal Antibody
[0040] Rabbits were immunized with the recombinant Tau protein and the resulting antibody was purified from the rabbit serum using a protein-A affinity column. This antibody recognizes multiple antigenic sites on Tau protein. This antibody will bind to both non-phosphorylated and phosphorylated forms of Tau protein.
[0000] Tau-5 Monoclonal Antibody (mAb)
[0041] The mouse mAb to Tau was raised using purified bovine microtubule-associated proteins (MAPs) as the immunogen. The resulting hybridoma was produced by fusing immunized BALB/c mouse splenocytes and mouse myeloma Sp2/0-Agl4 cells. It shows no cross-reaction with other MAPs or tubulin. it reacts with the non-phosphorylated as well as the phosphorylated forms of Tau and the reactive epitope maps to residues 210-230. This reagent is commercially available from Biosource International.
Total Tau ELISA and Phospho-Tau ELISA
[0042] A concentration of 2.5 μg/mL of Tau-5 monoclonal antibody in carbonate buffer, pH 9.4, was incubated at 100 μL/well in microtiter plates at 4° C. overnight. The wells were washed with a PBS/Tween-20 solution three times followed by blocking on other sites on the plastic surface with a buffered solution containing unrelated proteins such as BSA for 2 hours at room temperature. GSK-3β phosphorylated Tau, PKA phosphorylated Tau, and nonphosphorylated Tau were added to the wells at various concentrations and incubated for 1 hour at room temperature. After washing 3 times with Washing Buffer, the wells were incubated respectively with Tau pS 214 PSSA, Tau pS 199 PSSA or Pan-Tau antibodies at the optimized concentrations (ranging from 0.1 to 1 μp/mL) for 1 hour at room temperature. The plates then were washed three times with Washing Buffer, followed by the addition of an HRP conjugated anti-rabbit IgG secondary antibody at 1:5000 dilution for 1 hour at room temperature. After washing 3 times, 100 μL of Stabilized Chromogen was added to each well and then incubated for 20 minutes at room temperature in the dark. The OD values at 450 nm were measured following the addition of stop solution to each well.
Kinase Reactions
[0043] Phosphorylation of Tau using PKA was performed as follows. PICA was purchased from New England Biolabs. Recombinant Tau protein (1 μg) was incubated with various concentrations of PKA enzyme in buffer containing 50 mM Tris-HCl (pH 7.5), 10 mM MgCl 2 and 100 A1 ATP for 1 hour at 30° C.
Phosphorylation of Tau Using GSK-3β
[0044] GSK-3β was purchased from Upstate Biotechnology Inc. Recombinant Tau protein (1 pg) was incubated with various concentrations of the enzyme in buffer containing 40 mM HEPES (pH 7.2), 5 mM MgCl 2 , 5 mM EDTA, 100 μM ATP, and 50 μg/mL heparin for 1 hour at 30° C.
[0045] FIGS. 3 a and 3 b show the assessment of total Tau and selective Tau phosphorylation at the PKA/Ser 214 site by ELISA. In FIG. 3 a , phosphorylated Tau was detected by an ELISA using a PSSA specific for Tau pS 214 or by a pan-Tau antibody. Both antibodies detected the phosphorylated Tau protein with equal signals. In FIG. 3 b , non-phosphorylated Tau was placed into the same assay. As expected, the anti-Tau [pS 214 ] antibody failed to detect the Tau protein lacking the phosphate group at serine 214, whereas the pan-Tau antibody did detect the Tau protein.
[0046] FIGS. 4 a and 4 b show the assessment of total Tau vs. selective Tau phosphorylation at the GSK-3β/Ser 199/202 sites by ELISA. FIG. 4 a uses either non-phosphorylated Tau or GSK-3β-phosphorylated Tau in the ELISA with the anti-Tau pS 199/202 antibody. Nonphosphorylated Tau does not react in the ELISA, whereas the phosphorylated Tau shows strong signals. If the pan-Tan antibody is used as the detector, both proteins are readily detected ( FIG. 4 b ). FIG. 5 shows the direct relationship between the amount of phospho-Tau protein detected by ELISA and the quantity of protein kinase activity in the in vitro reaction. Various amounts of PKA enzyme were used to phosphorylate the Tau protein. Starting with the highest concentration of PKA, 5 units, (PICA tau 1), the PICA enzyme was then serially diluted 1:2 as shown, followed by a 1:1000 dilution and then applied to each well of the ELISA. Detection of phosphoTau was performed using the anti-Tau [pS214] (a PKA site). These data indicate that lower amounts of protein kinase in the reaction result in a proportionally lower amount of phosphoprotein produced, as detected in the ELISA. Thus, the ELISA signal provides an indirect, yet quantitative, measure of phosphokinase activity.
[0047] FIGS. 6 a and 6 b shows the specificity in detecting Tau protein phosphorylation catalyzed by PICA vs. G8100 enzymes using the Tau PSSAs and ELISA. The results demonstrate that the Tau pS 214 PSSA ELISA only detects Tau when phosphorylated by PICA and the Tau pS 199 PSSA ELISA only detects Tau when phosphorylated by GSIC3p.
[0048] FIG. 7 shows that the GSK3β enzyme can phosphorylate multiple sites on the Tau protein and PSSAs can independently detect the phosphorylated sites at Tau pT 181 , Tau pS 202 , Tau pS 199 /pS 242 , Tau pS 396 , and Tau pS 404 . This provides evidence that the ELISA is useful in creating a profile of phosphorylation events on the protein subjected to kinase enzyme activity. FIG. 8 shows the specificity of kinase reaction when tested as a profile with two antibodies, one specific for a PKA phosphorylation site (pS 214 ) and the other for a GSK site (pS 199 ) on Tau protein. A PKA-specific inhibitor, PKI (heat-stable inhibitor of c-AMPdependent protein kinase; New England Biolabs), was mixed at various ratios of inhibitor to enzyme (either PICA or GSK) and the resultant mixture analyzed by ELISA using the Tau PSSAs. The PICA-specific inhibitor altered the kinase activity of the pS 214 site alone. These data again attest to the specificity of the ELISA and the ability to independently monitor kinase activities on the same protein at different sites using the highly specific PSSAs as the assay detectors. These data also illustrate the capability of selectively screening for drug interference of protein kinase activity using this format.
[0049] Antibodies to other tau sites shown in Table II are also representative of the invention. Some of the phosphorylated sites are known to be associated with disease as further indicated in Table II.
[0000] TABLE II Disease Notes Phospho Site Linked (NGD = Neurodegenerative disease; FTD = T39 ? Phosphorylated by Casein kinase II T181, hu ? Involved in pretangle process? S184 Y Phosphorylated by GSK-3b; disrupts microtubule network S195 Y Phosphorylated by GSK-3b; disrupts microtubule network S198 Y Phosphorylated by GSK-3b; disrupts microtubule network S199 Y Phosphorylated by GSK-3b; linked to hereditary FTD S202 Y Microtubule-dependent phosphorylation by CDK 5 and GSK-3b; linked to hereditary NGD T205 Y Microtubule-dependent phosphorylation by CDK 5 and GSK-3b T212 Y Specific for NGD processes; phosphorylated by GSK-3b and PKA S214 Y Specific for NGD processes; may block aggregation; phos'd by PKA 2T17 ? T231 Y Involved in pretangle process?; phos'd by GSK-3b and S235 ? Microtubule-independent phosphorylation by GSK-3b S262 Y May block aggregation; phosphorylated by CAM K II and GSK-3b; major site in AD brain S320 ? S324 ? 5356 Y Involved in pretangle process?; AD pathway; major site in AD brain; phosphorylated by GSK-3b S361 ? S396 N Phos'd by GSK-3b S400 2 Phos'd by GSK-3b T403 ? S404 ? Involved in pretangle process?; microtubule-independent S409 Y AD pathway; phosphorylated by PKA S412 ? AD pathway 413 Y AD pathway; phosphorylated by GSK-3b 416 ? Phosphorylated by CAM K II 422 Y Linked with_several NGD's; phosphorylated by MAPK indicates data missing or illegible when filed
Rb System: This model system describes a large intra-nuclear protein with multiple phosphorylation sites that are acted upon by multiple protein kinases. Both phosphoserine and phosphotyrosine residues are examined, for which both mono-phospho and dual-phosphoresiducs are distinguishable in this model system.
Rb protein: Full length Rb protein is purified recombinant protein derived through cloning of human Rb cDNA and expressed in E. coli . The protein is purified via standard methods. This protein is commercially available from multiple vendors.
Rb [pT 821 ] PSSA: The rabbit antiserum was produced against a chemically synthesized phosphopeptide derived from a region of human Rb that contains threonine 821. Antibody was purified from rabbit serum by sequential epitope-specific chromatography. The antibody has been negatively preadsorbed using a non-phosphopeptide corresponding to the site of phosphorylation to remove antibody that is reactive with non-phosphorylated Rb. The final product is generated by affinity chromatography using a Rb-derived peptide that is phosphorylated at threonine 821. FIG. 9 defines the specificity of the anti-Rb [pT 821 ]. SDS-PAGE on a 7.5% Tris-glycine gel resolved cell extracts, prepared from MCF-7 cells. The proteins were then transferred to PVDF. Membranes were incubated with 0.5 g/mL antiRB[pT 821 ] following prior incubation in the absence (a) or presence of the peptide immunogen (b), the non-phosphopeptide corresponding to the RB phosphopeptide (c), the phosphopeptides corresponding to threonine 356 (d), serine 807/811 (e), serine 249/threonine 252 (f), and serine 751 (g) on phospho-RB. After washing, membranes were incubated with goat F(ab′) 2 anti-rabbit IgG alkaline phosphatase and bands were detected using the Tropix WesternStar™ method. The data show that only the phosphopeptide corresponding to this site blocks the antibody signal, demonstrating the specificity of the anti-Rb [pT 821 ] antibody for this phosphorylated residue.
Total Rb [pan] Detection Antibody: the detection antibody is a monoclonal, clone G3-245, available commercially from BD/Pharmingen (San Diego, Calif.). It recognizes an epitope between amino acids 332-344 of Rb protein. This antibody will bind to both nonphosphorylated and phosphorylated forms of Rb protein.
Rb monoclonal antibody: the capture antibody [linked to the solid phase] is a monoclonal, clone 3C8, available commercially from QED Biosciences (San Diego, Calif.). It reacts with epitope on near the C-terminal end of the Rb protein (aa886-aa905). This antibody will bind to both non-phosphorylated and phosphorylated forms of Rb protein.
Total Rb and Rb [pT 821 1 ELISA: A concentration of 1.25 μg/ml, of Rb monoclonal antibody in carbonate buffer, pH 9.4, was incubated at 100 uL/well in microtiter plates at 4° C. overnight. The wells were washed with a PBS/Tween-20 solution three times followed by blocking on other sites on the plastic surface with a buffered solution containing unrelated proteins such as BSA for 2 hours at room temperature. Jurkat cell lysate containing phosphorylated Rb or non-phosphorylated recombinant Rb were added to the wells at various concentrations and incubated for 2 hour at room temperature. After three washings with Washing Buffer, the wells were incubated, respectively, with Rb [pT 821 ] PSSA and biotinylated Pan-Rb antibodies at the optimized concentrations (ranging from 0.1 to 1 μg/mL) for 1 hour at room temperature. The plates then were washed three times with Washing Buffer, followed by the addition of an IMP conjugated anti-rabbit IgG secondary antibody at 1:5000 dilution or 0.25 μg/mL of streptavidin-HRP for I hour at room temperature. After washing, 100 III, of Stabilized Chromogen was added to each well and then incubated for 20 minutes at room temperature in the dark. The OD values at 450 nm were measured following the addition of stop solution to each well.
[0050] FIG. 10 shows studies to determine the specificity of the Rb [pT 821 ] ELISA. In the first study, solutions containing Rb protein at a concentration of 20 ng/mL from Jurkat, U2OS, and Co1o205 were analyzed with the Rb [pT 821 ] ELISA kit, along with a solution containing 20 nglmL purified full length Rb protein expressed in E. coli (non-phosphorylated). FIG. 11 shows that the Rb protein isolated from the cell lines was strongly recognized. These data provide evidence that appropriate phosphorylation of the Rb protein is requisite for reactivity in this assay.
[0051] In the second study, specificity for threonine 821 was determined by peptide competition. The data presented in FIG. 11 show that only the peptide corresponding to the region surrounding threonine 821, containing the phospho-threonine, could block the ELISA signal.
[0000] Kinase reactions for Rb: Natural sources for Rb were obtained for these studies from exponentially growing cells. Endogenous cellular kinases provided the phosphorylation of the natural Rb protein. FIG. 12 shows the application of this ELISA to study kinase reactions. Jurkat cells were grown in the presence of the kinase inhibitor, staurosporine, at various concentrations for 36 hours prior to lysis. Lysates were normalized for total Rh content using the Total Rb ELISA (BioSource International catalog #KHO0011). Levels of Rb phosphorylation at threonine 821 were determined. These data show that staurosporine inhibits the phosphorylation of Rb at threonine 821, presumably through the inhibition of cdks.
EGFR System: This model system presents an analysis of the cell surface receptor Epidermal Growth Factor Receptor (EGFR). This protein is a large transmembrane signaling protein with multiple phosphorylation sites consisting of phospho-threonine, phospho-serine and phospho-tyrosine residues.
EGFR protein: Human EGFR protein was purified from human carcinoma A431 cells by affinity purification. The product is purchased from Sigma (St. Louis, Mo.; cat #E-2645).
EGFR [pY 1173 1 PSSA: Rabbit antiserum was produced against a chemically synthesized phosphopeptide derived from the region of EGFR that contains tyrosine 1173. The sequence is conserved in human, mouse, and rat. Antibody was purified from serum by sequential epitope-specific chromatography. The antibody has been negatively preadsorbed using (i) a non-phosphopeptide corresponding to the site of phosphorylation to remove antibody that is reactive with non-phosphorylated EGFR enzyme, and (ii) a generic tyrosine phosphorylated peptide to remove antibody that is reactive with phospho-tyrosine (irrespective of the sequence). The final product is generated by affinity chromatography using an EGFR derived peptide that is phosphorylated at tyrosine 1173. FIG. 13 illustrates the specificity of the EGFR PSSA [pY 1173 ]. Cell extracts prepared from NIH3T3 cells expressing EGFR were starved for 30 hours, then stimulated for 10 minutes with 30 ng/mL EGF (+), or left unstimulated (−), then resolved by SDS-PAGE on a 6% Tris-glycine gel, and transferred to nitrocellulose. Membranes were incubated with 0.50 μg/ml anti-EGFR [pY 1173 ] antibody, following prior incubation in the absence (lanes 1 & 2), or presence of the peptide immunogen (lanes 3 & 4), or the non-phosphopeptide corresponding to the EGFR phosphopeptide (lanes 5 & 6). After washing, membranes were incubated with goat F(ab′) 2 anti-rabbit IgG alkaline phosphatase and bands were detected using the Tropix WesternStar™ detection method. The data show that only the phosphopeptide corresponding to this site blocks the antibody signal, demonstrating the specificity of the anti-EGFR [pY 1173 ] antibody for this phosphorylated residue.
EGFR [Py 845 1 PSSA: Prepared essentially as EGFR [pY 1173 ] PSSA but using chemically synthesized phosphopeptides from the region that contains tyrosine 845.
EGFR [Pan] monoclonal antibody: The capture antibody is a mouse monoclonal antibody, clone 199.12, available commercially from Neomarkers, Inc. (Union City, Calif.). It is specific for human EGFR and does not react with HER2/neu, HER3 and HER4. This antibody will bind to both non-phosphorylated and phosphorylated forms of EGFR protein and therefore is used as an initial capture antibody in the EGFR ELISA.
EGFR [Pan] Detection Antibody: This rabbit antibody was prepared by immunization with a synthetic peptide corresponding to C-terminus of human EGFR. The antibody was purified using protein A affinity column. It shows no cross-reactivity with HER2/neu, HER3 and HER4.
[0052] EGFR PSSA and Full Length ELISA: A concentration of 2.5 μg/mL of pan-EGFR monoclonal antibody in carbonate buffer, pH 9.4, was incubated at 100 μL/well in microtiter plates at 4° C. overnight. The wells were washed with a PBS/Tween-20 solution three times followed by blocking on other sites on the plastic surface with a buffered solution containing unrelated proteins such as BSA for 2 hours at room temperature. Autophosphorylated EGFR or non-phosphorylated EGFR were added to the wells at various concentrations and incubated for 1 hour at room temperature. After three washings with Washing Buffer, the wells were incubated, respectively, with EGFR [pY 845 ] PSSA, EGFR [pY 1173 ] PSSA, and Pan-EGFR antibodies at the optimized concentrations (ranging from 0.1 to I μg/mL) for 1 hour at room temperature. The plates then were washed three times with Washing Buffer, followed by the addition of an HRP conjugated anti-rabbit IgG secondary antibody at 1:2000 dilution for 1 hour at room temperature. After washing, 100 μL of Stabilized Chromogen was added to each well and then incubated for 20 minutes at room temperature in the dark. The OD values at 450 nm were measured following the addition of stop solution to each well.
[0053] The specificity of the EGFR [pY 1173 ] ELISA for tyrosine residue 1173 was determined by peptide competition. The data presented in FIG. 14 show that only the peptide corresponding to the region surrounding tyrosine residue 1173 and in the phosphorylated state could block the ELISA sipal generated with this PSSA.
Kinase Reactions: (Autophosphorylation)
[0054] EGFR was incubated to induce auto-phosphorylation in a buffer of 15 mM HEPES (pH7.4), 6 mM MnCl 2 and 15 mM MgCl 2 containing IμM ATP for 30 minutes at 30° C.
[0055] FIG. 15 demonstrates the dose-response curve of phosphorylation of EGFR in A431 cells after treatment with EGF at 1-500 ng/mL for 10 minutes. The level of tyrosine phosphorylation of EGFR at tyrosine 1173 was detected with the EGFR [pY 1173 ] ELISA.
[0056] FIG. 16 demonstrates use of the described invention to detect protein kinase activity associated with EGFR at tyrosine residue 845 and inhibition of that activity by a protein kinase inhibitor. In this assay, 2 ng/vial of purified human EGFR. was incubated (auto-phosphorylated) in the buffer of 15 mM HEPES (pH7.4), 6 mM MnCl 2 and 15 mM MgCl 2 containing 1 uM ATP for 30 minutes at 30° C. To inhibit phosphorylation of EGFR [py 845 ]′ tyrosine kinase inhibitor PD158780 (Calbiochem, cat #. 513035) was added to the reaction at the indicated concentration (see FIG. 16 ). EGFR [pY 845 ] phosphorylation was measured using 4 ng/mL of EGFR and the EGFR [pY 845 ] PSSA ELISA.
[0000]
TABLE 1
Table 1: Partial List of signal transduction proteins for which site-specific
phosphorylation can be determined by methods of the present invention.
Examples of Signal Transduction Proteins
Protein
A
alpha-actinin
alpha-synuclein
ABL/c-Abl (Abelson nonreceptor protein tyrosine kinase)
Acetylcholine Receptor
Ack nonreceptor protein tyrosine kinase;
Ak1JPKB serine/threonine protein kinase
AP-1 (Activator protein-1 jur/fos dirneric transcription factors
AP-2 (Activator protein-2 transcription factor
Apaf-I (Apoptosis protease-activating factor-1)
Apaf-2 (Apoptosis protease-activating factor-2/cytochrome C)
Apaf-3 (Apoptosis protease-activating factor-3/caspase-9
Arp⅔ (Actin related protein)
Atf-1 (Activating transcription factor-1)
Atf-2 (Activating transcription factor-2)
Atf-3 (Activating transcription factor-3)
Atf-4 (Activating transcription factor-4)
ATM(Ataxia Telangiectasia Mutated. Protein)
B
B-ATF nuclear basic leucine zipper protein/transcription factors
Bad
Bak
Bax
Bcl-2 (B-cell chronic lymphocytic leukemia 2)
Bc1-xL
Bc1-xS
BCR/ABL protein tyrosine kinase
beta-Catenin
BID (BH-3 Interacting Death Domain)
Blk (B Lymphocyte Src non-receptor protein tyrosine kinase family member)
BMK-1 (Big Map Kinase/ERK5)
Btk (Bruton's Tyrosine Kinase)
C
Cadherin
CADTK (calcium activated protein tyrosine
kinase/Cakbetalpyk2/FAK2fRAFTK) CAK (Cdk-Activating Kinase)
Cak-beta (Cell adhesion kinase beta/CADTK/Pyk2/FAK2/RAFTK)
caldesmon
calmodulin
calpain cysteine proteases
CaM kinase 11 (Calmodulin-dependent protein kinase II)
CB 1 (Cannabinoid Receptor 1)
CB2 (Cannabinoid Receptor 2)
caspase-2 (Cysteine Aspartyl Protease-2/ICH-1/NEDD-2)
caspase-3 (Cysteine Aspartyl Protcase-3/LICE/CPP32/YAMA/apopain/SCA-1)
caspase-8 (Cysteine Aspartyl Protease-8/MACH/FLICE/Mch5)
caspase-9 (Cysteine Aspartyl Protease-9/1CE-LAP6/Mch6/APAF-3)
Caveolin 1, 2, and 3)
CD45 transmembrane tyrosine phosphatase
CD45AP (CD45-associated protein)
c-fos transcription factor
CDK1/cdc2 (Cyclin-dependent kinase-1)
CDK2 (Cyclin dependent kinase-2)
CDK4 (Cyclin dependent kinase-4)
CDK5 (Cyclin dependent kinase-5)
c-Jun transcription factor
c-myc transcription factor
Cortactin
COX-2 (Cyclooxygenasc-2/prostaglandin-endoperoxide synthase-2)
c-kit receptor protein
c-raf protein serine/threonine kinase
CREB transcription factor
Crk SH2 and SH3 domain-containing adaptor protein
CSK (Carboxyl-terminal Src Kinase)
cytochrome-c
D
DAPK (Death Associated Protein Kinase)
desmin
DNA-PK (DNA dependent protein kinase)
E
E2F-1 DNA binding protein
EGF-R (Epidermal Growth Factor Receptor)
eIF-2alpha (Eukaryotic translation Initiation Factor 2alpha)
ERK1/MAPK (Extracellular signal-Regulated/Nlitogen-Activated Protein Kinase 1)
ERIK2/MAPK (Extracellular signal-RegulatedMitogen-Activated Protein Kinase 2)
ERK3 (Extracellular signal-Regulated/p62 Mitogen-Activated Protein Kinase 3)
ERK4 (Extracellular signal-Regulated Protein Kinase 4)
ERK5 (Extracellular signal-Regulated Protein Kinase 5/Big MAP Kinase 1)
ERK6 (Extracellular signal-Regulated Protein Kinase 6/p38garruna)
ERK7 (Extracellular siznal-Regulated Protein Kinase 7)
ERK5 (Extracellular signal-Regulated Protein Kinase 8)
F
F-actin
FADD (Fas-associated Death Domain)
FAK (Focal Adhesion Kinase/pp125FAK)
FAS (FAS-Ligand Receptor)
F C, non-receptor Src family tyrosine kinase
Fos B
Fra-1 (Fos-related antigen-1)
Fra-2 (Fos-related Antigen-2)
FRK (Fos-Regulating Kinase)
FYB (Fyn binding protein)
Fyn non-receptor Src family tyrosine kinase
G
Gab 1 (Grb2-associated binder 1)
Gab 2 (Grb2-associated binder 2)
GCK (Germinal Center Kinase)
GEF (Guanine nucleotide Exchange Factor)
Giα inhibitory guanine nucleotide regulatory protein
Giβ inhibitory guanine nucleotide regulatory protein
Giγ inhibitory guanine nucleotide regulatory protein
Gq/11guanine nucleotide-binding protein
Gq/11β guanine nucleotide-binding protein
Gq/11γ guanine nucleotide-binding protein
Grb2 (Growth factor Receptor Binding protein-2)
Grk2 (G protein-coupled Receptor Kinase)
GSK-3α (Glycogen Synthase Kinase 3alpha)
GSK-3β (Glycogen Synthase Kinase 3beta)
H
Hck (Hematopoietic cell kinase)
HGF-R (Hepatocyte growth factor receptor)
Hrk (3-Hydroxy-3-methyl glutaryl-coenzyme A Reductase Kinase)
I
IkappaB alpha NFkB inhibitory protein
IkappaB beta NFkB inhibitory protein
IKKalpha (IkB kinase alpha)
IKKbeta (IkB kinase beta)
IKKgamma (IkB kinase gamma/NEMO)
1GF-I receptor (Insulin-like growth factor-I receptor)
Insulin receptor
Integrins
Integrin-Associated Protein (IAP/CD47)
IRAK (Interleukin-1 Receptor-Associated Kinase)
IRK (Insulin Receptor Kinase)
IRS-1 (Insulin Receptor Substrate 1) IRS-2 (Insulin Receptor Substrate 2)
J
JABI (Jun-Activation domain Binding protein I)
SAKI (Janus Activating Kinase 1)
JAK2 (Janus Activating Kinase 2)
JAK3 (Janus Activating Kinase 3)
JNK1/SAPKγ (c-Jun amino-terminal kinase I/Stress-Activated Protein Kinase y)
INK2/SAPKβ (c-Jun amino-terminal kinase 2/Stress-Activated Protein Kinase 13)
JNK3/SAPKα(c-Jun amino-terminal kinase 3/Stress-Activated Protein Kinase a)
L
LAST (Linker for Activation of T cells)
Lck non-receptor Src family protein tyrosine kinase
Lyn non-receptor Src family protein tyrosine kinase
M
MEF2c transcription factor
MEKI (Mitogen-activated ERK-activating Kinase 1)
MEK2 (Mitogen-activated ERK-activating Kinase 2)
MEK3 (Mitogen-activated ERK-activating Kinase 3)
MEK4 (Mitogen-activated ERK-activating Kinase 4)
MEK5 (Mitogen-activated ERK-activating Kinase 5)
MEKKI (MEK kinase 1)
Met (c-metEGF-receptor)
MKP 1 (MAP Kinase Phosphatase 1)
MKP 2 (MAP Kinase Phosphatase 2)
MKP 3 (MAP Kinase Phosphatase 3)
MKP 4 (MAP Kinase Phosphatase 4)
MKP 5 (MAP Kinase Phosphatase 5)
MKP 6 (MAP Kinase Phosphatase 6)
MLCK (Myosin light chain kinase)
MuSK (Muscle specific serine/threonine kinase)
Myosin
MLCK PPase (Myosin Light Chain Kinase Phosphatase)
N
Beta-NAP (Beta-Neuron Adaptor Protein/AP-3)
NATI/DAP-5 (Novel APOBEC-1 Target no. 1/Death-Associated Protein-5)
NCK SH2 and SH3 domains-containing transforming protein
Nek2 (Nima-related Kinase2)
NFAT-1 (Nuclear Factor of Activated T-cells)
NfkappaB (Nuclear Factor Kappa B transcription factor)
NIK (NFkappaB Inducing Kinase)
NTK (Nervous Tissue and T cell Kinase)
P
p130cas
p190Rho GAP GTPase
P2Y2 purinoceptor
p36 CAK assembly/activation factor
p38 (ERK6 MAPK/SAPK)
p38d (SAPK4)
p53 Tumor suppressor gene.
p58 IPK (Inhibitor of the interferon-induced double-stranded RNA-activated Protein Kinase,
PKR)
p62dok GAP-associated protein
p62 lck ligand/ZIP
p68 kinase
p96
PAK1 (p21-Activated protein Kinase 1)
PAK2 (p21-Activated protein Kinase 2)
PAK3 (p21-Activated protein Kinase 3)
PARP (Poly(ADP-Ribose) Polyrncrase)
Paxillin
PCNA (Proliferating Cell Nuclear Antigen)
PDGF Receptor (Platelet Derived Growth Factor Receptor)
PDK1 (Phosphoinositide-Dependent Kinase-1)
PDK-2 (Phosphoinositide-Dependent Kinase-2/Integrin-linked kinase)
PECAM-1 (Platelet-Endothelial Cell Adhesion Molecule-1)
P13K (Phosphatidyl Inosito 1-3-Kinase)
PIAS (Protein Inhibitors of Activated STATs)
PITP alpha (Phosphatidylinositol Transfer Protein alpha)
PKA alpha/cAMP-dependent protein kinase
PKB (Protein kinase B)
PKC alpha (Protein Kinase C alpha)
PKC beta (Protein Kinase C beta)
PKC delta (Protein Kinase C delta)
PKC gamma (Protein Kinase C gamma)
PKD (Protein Kinase D)
PKR (Protein Kinase R or double-stranded RNA-activated protein kinase)
PLC-gamma 1 (Phospholipase C-gamma 1)
PRK (Proliferation Related Kinase)
PTEN (MMAC1 tumor suppressor gene/protein phosphatase)
Pyk2 (CAKbeta/FAK2/RAFTK) Protein tyrosine Kinase
R
Rac/cdc42 GTPase
Rafl (C-raf) serineithreonine protein kinase
A-Raf serine/threonine protein kinase
B-raf serine/threonine kinase
V-Raf viral serine/threonine protein kinase
RAFTK (Related Adhesion Focal Tyrosine Kinase)
RAIDD (RIP-Associated ICH-1/CED-3 homologous protein with a Death Domain)
Rapt GTPase
Rap 1-GAP (C3G) inactivator of Rap-1
Rapsyn
Ras GTPase
Rb (Retinoblastoma tumor suppressor protein)
Rho Small molecular weight GTPase
RIP (Receptor Interacting Protein)
ROCK (Rho-activated kinase)
S
S6k (S6 Kinase)
Shc
SHIP (SH2 domain containing inositol phosphatase)
SH-PTPI Protein Tyrosine Phosphatase
SH-PTP2 Protein Tyrosine Phosphatase
SIRPalpha1 (Signal Related Protein Alpha)
SIP1 (Smad Interacting Protein 1)
Smad2 (Sma and Mad-related 2)
Smad3 (Sma and Mad-related 3
Smad5 (Sma and Mad-related 5)
Smad7 (Sma and Mad-related 7)
SOCS-1 (Suppressor of Cytokine Signaling-1)
SOCS-2 (Suppressor of Cytokine Signaling-2)
SOCS-3 (Suppressor of Cytokine Signaling-3)
SOS (Son of Sevenless)
Src non-receptor tyrosine kinase
SRF (Serum Response Factor)
SRPK1 (SR protein-specific Kinase 1)
SRPK2 (SR protein-specific Kinase2)
STAT1alpha (Signal Transducer and Activator of Transcription 1)
STAT2 (Signal Transducer and Activator of Transcription 2)
STAT3 (Signal Transducer and Activator of Transcription 3)
STAT4 (Signal Transducer and Activator of Transcription 4)
STAT5alpha (Signal Transducer and Activator of Transcription 5alpha)
STAT5beta (Signal Transducer and Activator of Transcription 5 beta)
STAT6 (Signal Transducer and Activator of Transcription 6)
Syk (Spleen tyrosine kinase)
Syndecans transmembrane proteoglycan
T
Takl (TGF-bl activated kinase)
Talin
TANKII-TRAF (TNT Receptor Activating Factor)
Tau mierotubule-associated protein
TBK-liT2K (TANK Binding Kinase 1)
Tensin
TNF-RI (Tumor Necrosis Factor Receptor I)
TRADD (TNT-Receptor Associated Death Domain protein)
TRAF1 (TNF-Receptor Associated Factor 1)
TRAF2 (TNF-Receptor Associated Factor 2)
TRAF3 (TNF-Receptor Associated Factor 3)
TRAF4 (TNF-Receptor Associated Factor 4)
TRAF5 (TNF-Receptor Associated Factor 5)
TRAF6 (TNF-Receptor Associated Factor 6)
TrkA protein tyrosine receptor kinase A
TrkB protein tyrosine receptor kinase B
TrkC protein tyrosine receptor kinase C
V
VEGF-receptor (vascular endothelial growth factor receptor, types 1. 2, 3)
Vinculin
W
WASP (Wiskott-Aldrich Syndrome Protein)
Z
ZIP (Zeta Interacting Protein)
ZIP kinase (zipper serine/hreonine kinase)
ZRP-1 (Zyxin Related Protein
Zyxin
[0057] The examples provided illustrate the present invention and are not intended to limit the invention in spirit or scope. Similarly, the description of these reagents and methods can be used in an inverse function to analyze the activity of protein specific phosphatases, enzymes that remove phosphate groups from specific amino acid residues. In addition, Antibodies of the present invention are also useful for inactivating phosphorylated polypeptides for therapeutic purposes.
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The invention involves a method for measuring phosphorylation of proteins at specific sites and, as such, is an indicator of the protein kinase activity of enzymes capable of phosphorylating those sites. The method involves the in vitro or in vivo phosphorylation of a target protein at a specific serine, threonine or tyrosine residue, subjecting that protein (non-phosphorylated) to reaction mixture containing all reagents, including phosphokinase which allow the creation of a phosphorylated form of protein. The phosphorylated protein is measured by contacting it with an antibody specific for the phosphorylation site(s). The invention includes antibodies useful in practicing the methods of the invention. The invention particularly relates to all proteins modified by phosphorylation and dephosphorylation as illustrated by Tau, Rb and EGFR proteins and antibodies specific for the site of phosphorylation of the Tau, Rb or EGFR proteins.
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RELATED APPLICATIONS
The present application is related to co-pending application entitled "ATM NETWORK AVAILABLE BIT RATE (ABR) FLOW CONTROL SYSTEM", U.S. Ser. No. 08/978,178, filed on Nov. 25, 1997, and "METHOD AND APPARATUS FOR ALLOCATION OF AVAILABLE BANDWIDTH" U.S. Ser. No. 08/977,220, Filed on Nov. 24, 1997 both assigned to the assignee of the present application and included herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to data communications networks and more particularly to a flow control system for regulating information transfer rate within networks.
BACKGROUND OF THE INVENTION
Efficient informational flow control has been an important consideration in the research and design of high speed communications networks. Flow control processing varies a sender's allowable rate of information transfer in response to feedback from the network within which the information is being transferred. In an exemplary embodiment, a traffic source sends a "probe" message into the network and receives a "reply" from the traffic destination end system. This information flow happens continuously (as long as data is available at the source) so the source receives information every "round-trip" time. If a network is not congested, the session's source of the information being transferred is allowed to increase the rate at which the information is sent thereby taking greater advantage of available bandwidth. When more congestion is present, the rate is reduced. Typically the sending rate of a session during which information is being transferred will oscillate around a desired operating point.
A session with a short propagation delay receives and reacts to feedback from the network much faster than a session with a long propagation delay. This can cause an unfair allocation of available bandwidth, i.e. closer nodes will be granted bandwidth at a disproportionate rate relative to nodes which are located a greater distance away. The sending rate for an information packet is decreased if one of the nodes along its path is congested. That "greater distance" information transfer is therefore at a disadvantage with respect to sessions traversing a single "hop", or relatively fewer "hops" between source and destination nodes
Thus, in typical rate-based flow-controlled methodologies, connection "length" (for example the propagation delay across the network as measured by the endpoints) affects bandwidth allocation fairness. This is especially true of rate control schemes in which rate changes occur at times controlled by the round-trip time experienced during network operation. For example, in systems where rate increases are accomplished according to the sender receiving a congestion message from the receiver based on a control loop determined by the round trip time, connections which have smaller round-trip times have an advantage in that their rate increase epochs occur more frequently, and thus the closer nodes can obtain a larger allocation of the shared link bandwidth if they do not scale their increases according to a globally-set baseline increase amount and their experienced round-trip or update times.
Therefore there is a need for an improved methodology for determining and assigning allocations of available bandwidth for data transfers within networking systems.
SUMMARY OF THE INVENTION
A data transfer flow control system for a packet communications system includes a plurality of nodes interconnected by transmission links. The rate at which a sender node transmits information to a destination node in a network is modified in accordance with congestion information returned to the sender node from nodes along the path of the transmission. The rate change for information being sent from the sender node is modified based upon the amount of elapsed time occurring since the last rate change of the same type. In first and second examples, the rate change is implemented in accordance with exponential and linear relationships, respectively, between the modified flow rate and the elapsed time since the last rate change.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention can be obtained when the following detailed description of a preferred embodiment is considered in conjunction with the following drawings, in which:
FIG. 1 is a schematic representation of a packet switching network within which the present invention may be used;
FIG. 2 is illustrative of the kinds of data processing and/or communication equipment which can exist at a node in a network; and
FIG. 3 is a high level view of components of a data processing/handling system which can be used to implement the present invention.
DETAILED DESCRIPTION
Mainframe 22 with a number of directly connected terminals, such as terminals 24a, 24b and 24c used to support input/output operations for a transaction processing application for example, such as credit verification. The node would also include a packet network access switch 26 connected both the remainder of the ATM network (not shown) and to the mainframe and possibly to a local area network 28 and one or more terminals, such as terminals 30a and 30b, used in a high bandwidth application for example, such as a videoconferencing application. In a given installation, additional controllers or network elements, such as a communication controller or a router, might be part of the system. For example, a router or a communication controller (neither of which is shown) might be interposed between the mainframe 22 and the ATM access switch 26. Similarly, the terminals 24 might be connected indirectly to mainframe 22 through a display controller (not shown). A packet network access switch can perform a number of functions in a typical system. The access switch may serve to aggregate or concentrate data provided by the various connected components.
As shown in FIG. 3, a typical general purpose data processing control system 40 would include a central processing unit 42, control and data memory 44, input buffers 46 for temporarily storing packets/data received from other nodes in the network, link state registers 48 for storing information about the state of various links connected to the system and a packet I/O handler 50 for performing necessary input/out and switching functions. Different queues may be used for different classes of ATM traffic although each queue operates on a First-In First-Out basis.
As shown in FIG. 1, a packet switching system is commonly referred to as including a cloud 10, cloud being a term of art that collectively represents the various nodes (communication systems) and links (transmission media) that are within the system. For a particular data path set up between a traffic source 14 and a traffic destination 20, the nodes can be characterized as intermediate nodes, such as nodes 12a through 12f, or endpoint nodes. An endpoint node is either a source or destination system in combination with the hardware and software needed to access the remainder of the packet switching network. The combination of traffic source 14 and an packet network access switch 16 is an example of a source endpoint 15 while the combination of traffic destination 20 and packet network access switch 18 is an example of a destination endpoint 19.
The role (and characterization) of any particular node may change for different network connections. For example, for a different connection, endpoint 19 might either serve as a traffic source or as an intermediate node on a path between two other nodes.
The various nodes are shown as being interconnected by links, such as link 11. The representation of the links is not intended to imply that all of the links are the same. Each link may be any of several known types of media capable of supporting high speed digital traffic, including copper wire, optical fiber or even microwave or satellite wireless links.
FIG. 2 is a more detailed representation of the kind of data processing equipment that might be found at a typical node in a packet network system. The node could include a Traffic sources 14 and traffic destinations 20 (or any element implementing a rate control methodology) can deduce network conditions from timing information. For example, a traffic source might include timing information in the source's probe packets. The traffic destination can then combine that information with information measured at the destination point. From that combination, the traffic destination can then deduce the congestion level experienced by the probe packet. From that deduction, the traffic destination would form a control message to be sent to the traffic source. The control message, or "reply" message, would indicate, for example, that the source should increase or decrease its sending rate. Thus, the traffic source and traffic destination form a control loop based on the present round-trip time.
The source then adjusts the source rate based on the feedback congestion information contained in the reply message. In an exemplary networking system, a sender (or source endpoint implementing a rate-based flow control methodology) transmits data at a rate which changes over time and according to congestion messages received during the transmission. The system implements one of several ways by which the sender obtains the congestion information from the connection receiver or the network elements. When provided by the connection receiver, the congestion information may be deduced from network congestion indications, or from network delay changes (since they are affected by congestion within the network buffers). The sender obtains the congestion information at certain points in time which can occur at different frequencies depending on connection length and/or end station timer granularity. In the example, a sender sends a "probe" message into the network and receives a response indicative of network congestion conditions at the time. Thus the sender has only one outstanding "probe" message in the network at any one time.
The sender's probe message summons a response message which can be formulated by either the receiver endpoint or a network internal node. In either case, the sender receives a reply message and then changes the sender rate in reaction to the response message. The response message may contain various information, but the method described applies to the case when the response message contains "increase rate" or "decrease rate" information rather than containing a new and specified sending rate or value for implementation by the sender.
In response to the increase/decrease information, the sender calculates a new sending rate and transmits at the new rate until another response message is received according to the specific timing schedule used in the flow control methodology. Typically a rate adjustment will be done according to some pre-determined rate change function (linear, exponential, etc.). The method described herein applies to systems in which the increases and/or decreases are determined by a methodology based on discrete steps. The common methodology maps increase/decrease information received and sends messages at a new sending rate that is determined independently of the amount of time that occurred between the steps. The disclosed method involves additionally computing rate changes based on the time elapsed between rate changes rather that changing rates by a fixed amount whenever a reply message arrives.
In an example, a networking system can have the connection receiver node determine congestion conditions and send a reply message back to the sender node to signal the sender to adjust the sending rate. In that case, the time between rate adjustments will depend on the round trip time of the connection. Methodologies that adjust their rates based on a "static" increase curve will allow unfairness to occur since connections having short propagation delays or connection lengths, have an advantage in that they can increase their rates more frequently or at a higher frequency, thus obtaining a greater portion of the shared link bandwidth. According to the presently disclosed methodology, the size of the sender rate change is adjusted in relation to the time between rate changes. The adjustment may be in accordance with any of several selectable rate curve relationships including linear and exponential among others.
In every system, it is necessary to establish a "baseline" connection length that is used as a global reference for determining step sizes in rate changes. The baseline is given by the longest connection for which a fair allocation is important. Connections which are longer will receive a smaller allocation because their step sizes are the same as the baseline connection but their change frequency is lower. To assure accurate allocation of bandwidth for connections "shorter" than the baseline, the increments are scaled according to the actual time between changes. Using the longest connection length as the baseline is not necessary but establishing a baseline is necessary to provide a global value against which all scaling can be done so that fair allocation can be achieved.
In the example where an exponential rate curve is implemented, the sender increases its sending rate by an amount governed by an exponential curve when it receives "increase" information in a reply message. The amount of the increase in one example is related to a rate increase control parameter "λ" which is generally chosen to obtain acceptable performance, the asymptotic/goal rate "r(A)" for the sender, and an initial sensing rate "r(0)". If, for example, the increase curve is set to be identical in time for two connections having different lengths. Thus there will be a first time factor "t(L)" representing the time between rate increases for the "long" connection, and a second time factor "t(S)" representing the time between rate increases for the second and relatively shorter connection. The approach taken, though not required, is to set the rate increase parameter for the long connection and compute increase amounts for shorter connections from the setting chosen for the baseline long connection.
To implement an exponential rate increase function is equivalent to increasing a sender's rate (at the increase epochs) such that the next sender rate is related to the present sender rate plus an increase factor. The increase factor is related to the quantity of the asymptotic rate less the present rate, with that quantity divided by a control parameter "k". At the rate increase epochs (which occur at the reply message processing times), the rate is increased by a fraction of the distance (1/k) from the present sending rate to the asymptotic/goal rate where "k" is seen as the new control parameter. The control parameters are different but may be related. Then assuming, without loss of generality, that each sender starts their rate at rate r(0) at time t(0), and they are to have the same rate at the next time they change their rates at identical times. That future time (t') is given by the lowest common multiple of their update times. It can then be determined that the increase factor "k(s)" is necessary so that the short node and the far node to have the same rate increase functions would be equal to the quantity "1" (one) divided by a quantity equal to "1" minus a distance relativity factor. The distance relativity factor would equal "γ" to the power given by the ratio of the shorter receiver node distance "1(s)" divided by the longer receiver node distance "1(1)". The quantity "γ" in the example is equal to the quantity "k(1)-1" divided by the quantity "k(1)". This gives the calculation for the increase factor k(s) for the short connection. It is presumed that k(1) for the long connection has been chosen as the baseline increase control parameter for the network. A linear approximation can also be derived for the quantity k(s) in order to simplify the calculations done during the execution of the disclosed methodology.
The calculation for k(s) provides a means for adjusting the steps taken by connections as the delays vary. The sender in this example is taken to be one having a "short" connection length or "1(s)". The method would be implemented such that when a sender receives a reply message and determines that an increase beyond its previous rate should occur, 1(s) is determined by monitoring the time between rate changes and then computing k(s) based on the above methodology. The rate increase expression "r(next)=r(present)+[r(asymptotic)-r(present)]/k(s)" to determine its next rate. If the experienced time between rate increases is greater than 1(1), then k(s)=k(1) would be used.
In an exemplary linear increase application, a linear curve is used to govern the rate increases rather than a exponential curve, and the determination of k(s) differs accordingly. In a linear example, where "I" is the rate increase control parameter, and the initial rate is r(0), then r(t)=r(0)+(I*t). Expressing the increases at the rate increase epochs gives: "r(next)=r(present)+I". Equating the rates at the first common change time gives: "[I(1)]*[1(s)]=[I(s)]*[1(1)]". This gives the expression for the rate increase control parameter for short connections I(s) to be equal to the rate increase control parameter for long connections I(1) multiplied by the quotient of the short inter-node length 1(s) divided by the long inter-node length 1(1).
Using similar arguments on "decrease" message processing leads to similar results for decrease amounts as a function of connection "lengths". The calculations are identical in concept to those presented above.
The method and apparatus of the present invention has been described in connection with a preferred embodiment as disclosed herein. Although an embodiment of the present invention has been shown and described in detail herein, along with certain variants thereof, many other varied embodiments that incorporate the teachings of the invention may be easily constructed by those skilled in the art, and the methodology may even be included or integrated into a processor or CPU or other larger system integrated circuit or chip. The methodology may also be implemented partially or solely in program code which may be executed to function as described herein. Accordingly, the present invention is not intended to be limited to the specific form set forth herein, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents, as can be reasonably included within the spirit and scope of the invention.
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A data transfer flow control system for a packet communications system includes a plurality of nodes interconnected by transmission links. The rate at which a sender node transmits information to a destination node in a network is modified in accordance with congestion information returned to the sender node from nodes along the path of the transmission or from the information receiver. The rate change for information being sent from the sender node is modified based upon the amount of elapsed time occurring since the last rate change of the same type. In first and second examples, the rate change is implemented in accordance with exponential and linear relationships, respectively, between the modified flow rate and the elapsed time since the last rate change.
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FIELD OF THE INVENTION
This invention relates to devices that retain and position tools. More specifically, this invention relates to a headband that retains and positions a flashlight for hands-free operation but which can be arranged to form a protective case or holster for the flashlight.
BACKGROUND OF THE INVENTION
Headbands for retaining and positioning flashlights are known. Typical of such devices is the one shown in U.S. Pat. No. 5,053,932, granted on Oct. 1, 1991, to Richard N. Case for a "Flashlight Retainer". The '932 patent describes an elongated band having two ends adapted to releasably engage each other so as to form a circular headband having an outside face and an inside face. The inside face fits snugly against the head of the user while the outside face includes an elastic loop for retaining and positioning a flashlight.
Other similar devices are known. Typically, these devices differ by their means for retaining the flashlight or by their means for adjusting the headband to fit different head sizes. Examples of such other devices are shown in U.S. Pat. No. 4,797,793, granted on Jan. 10, 1989, to Tom R. Fields for a "Headband for Holding a Flashlight", U.S. Pat. No. 5,217,294, granted on Jun. 8, 1993, to James W. Liston for a "Head Mounted Multi-Position Flashlight Holder", and U.S. Pat. No. 4,970,631, granted on Nov. 13, 1990, to Timothy E. Marshall for a "Headband Device for Holding Flashlight".
Unfortunately, known flashlight-retaining headbands have a number of disadvantages.
Although these devices are suitable for retaining a flashlight on a person's head, this arrangement is not the normal state for either the flashlight or the person. People generally do not walk about with flashlights on their heads and flashlights are generally found in places other than on people's heads.
The known headbands do not assist a person to carry a flashlight anywhere except on the head. Designed for active flashlight use, these devices expose the flashlight to damage during passive carriage.
When not worn, the headband is loose and susceptible to snagging on objects. To avoid snagging the headband, the user must either wrap it cumbersomely around the flashlight or remove it entirely and store it separately from the flashlight. In either case, over time the user will be prone to forget the headband, to lose it, or to intentionally leave it behind. Without the headband, the user must either carry the flashlight in hand or find an alternative device for retaining or carrying the flashlight.
Similarly, the known devices are not suitable for storing a flashlight between uses. They leave the flashlight exposed and susceptible to damage, and their elongated, flexible structure is prone to becoming a tangled mess.
What is needed is a flashlight-retaining headband that is also suitable for carrying the flashlight during passive use and for storing the flashlight between uses. The present invention is directed to such a device.
SUMMARY OF THE INVENTION
According to one aspect of the invention there is provided an apparatus for retaining and positioning an object, comprising: a substantially flexible member having a first end, a second end opposite the first end, opposite longitudinal edges, a first surface bounded by the first end, the second end and the edges, and a second surface opposite the first surface, means, connected to the first surface, for retaining and positioning the object, first alternate means for reversibly closing the flexible member to form a single loop with the portion of the first surface proximate the object-retaining means defining a section of exterior surface exposing the object-retaining means, and second alternate means for reversibly closing the flexible member such that the portion of the first surface proximate the object-retaining means defines a section of interior surface covering the object-retaining means.
The member can be either unitary or constructed of discrete sections. Each of the discrete sections might be substantially rigid, substantially elastic or substantially inelastic.
The retaining means can be either a pocket, a loop, or a fastener, and can include means for increasing the frictional forces between the object and the retaining means. The retaining means can be attached to the member proximate to the midpoint between the first end and the second end or proximate to the first end.
The first alternate closing means can include cooperating patches of hook and loop material, a fastener, or a cooperating pair of male and female connectors. The second alternate closing means can further include means for releasably retaining a mounting device, such as a belt.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a top perspective of a headband embodying one aspect of the invention, in its open configuration;
FIG. 2 is a top perspective of the headband of FIG. 1, in its headband or loop configuration;
FIG. 3 is a top perspective of the headband of FIG. 1, in a storage configuration which also can act as a holster configuration;
FIG. 4 is a side elevation of the headband of FIG. 1, in the storage-holster configuration of FIG. 3;
FIG. 5 is a side elevation of a first alternative embodiment of a headband in accordance with the present invention, in a storage-holster configuration;
FIG. 6 is a side elevation of a second alternative embodiment of a headband in accordance with the present invention, in a storage-holster configuration;
FIG. 7 is a side elevation of a third alternative embodiment of a headband in accordance with the present invention, in a storage-holster configuration;
FIG. 8 is a side elevation of a fourth alternative embodiment of a headband in accordance with the present invention, in a storage-holster configuration;
FIG. 9 is a side elevation of a fifth alternative embodiment of a headband in accordance with the present invention, in a storage-holster configuration;
FIG. 10 is a side elevation of a sixth alternative embodiment of a headband in accordance with the present invention, in a storage-holster configuration; and
FIG. 11 is a side elevation of a seventh alternative embodiment of a headband in accordance with the present invention, in a storage-holster configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIGS. 1 and 2, the headband 100 embodying one aspect of the invention is formed from an elongated band 110 having a first end 112, a second end 114 opposite the first end, first and second longitudinal edges 116 and 118, respectively, a first face 120 bounded by the first and second ends 112, 114 and the first and second edges 116, 118 and a second face 122 opposite the first face 120. The first and second ends 112, 114 may include first and second terminators such as metal clips or heavy-duty stitching to improve resistance to wear and prevent unraveling.
The band may be constructed of either an elastic or an inelastic material that is durable and comfortable to wear. A preferred elastic material is two inch wide polyester braided elastic. A preferred nonelastic material is cordura, a polyester-based canvas-like material. The materials are generically known as belting or narrow fabrics.
A short strip of material 124, approximately the same width as the band 110, is affixed to a portion of the band between its first end 112 and its second end 114. The strip 124 has a first end 126, and a second end 128 opposite the first end 126. The longitudinal margins of the strip 124 are affixed to the band 110 by stitching, metal or plastic hardware fasteners, or chemical or fusion bonds such that a pocket 140 is formed between the first surface 120 of the band 110 and the strip 124. The pocket opens along the second end 128 of the pocket-forming strip. The first end 126 of the strip can also be open, but preferably is closed by having its margin affixed to the first surface 120 of the band. The pocket 140 is sized for retaining and positioning a device such as a miniature flashlight F.
Complemental connectors are located along the band 110. For example, the connectors can be patches of complemental hook and loop materials, or mating male and female pins and sockets, or any other complemental fastenings or connectors which securely, but detachably, connect to each other, preferably by engagement. Other examples of such complementary connector pairs are: positive and negative poles of magnets, male and female snaps, buttons and buttonholes, tongue and groove fasteners, bolts and nuts, balls and sockets, hooks and clasps, mated compression fittings, and generally male and female connectors. Other examples of pairs of connectors which are similar but which are considered "complemental" for the purposes of this application are: laces, ties and zippers. Where an endpoint 112, 114 of the band 110 is being connected, it is also contemplated that a loop, D-ring, cleat, clamp, clasp, barb or other such tie-point would be an appropriate connector. Where the two endpoints 112, 114 of the band 110 are being connected together, it is contemplated that they could be knotted or otherwise tied together. In the preferred embodiment, hook and loop fastening patches are used. Connectors of one type are referred to as "positive," have reference numbers with an "a" suffix and are stippled, while connectors of the other, complemental type are referred to as "negative," have reference numbers with a "b" suffix and are marked with horizontal cross hatches.
At the first end 112 of the band 110 are a first negative connector 160b located on the first surface 120, and a second negative connector 162b located on the second surface 122. A third negative connector 164b is located on the outside surface of the pocket-forming strip 124 toward its first end 126.
At the second end 114 of the band 110 is a first positive connector 180a located on the first surface 120. A second positive connector 182a is located on the second surface 122 of the band 110 between its first and second ends 112, 114 and close to the second end 128 of the pocket-forming strip 124.
With reference to FIG. 2, the band 110 will now be described as operated in headband configuration. Without twisting the band 110 about its longitudinal centerline, the user wraps the band 110 into a single loop such that the first end 112 and the second end 114 are overlapping and proximate, with the second end 114 located to the inside of the first end 112. The second negative connector 162b and the first positive connector 180a are then brought together and releasably engaged to close the loop. The loop forms a substantially cylindrical shell having an exterior surface formed by the first surface 120 and an interior surface formed by the second surface 122. The pocket formed by strip 124 opens at the exterior surface and thereby is disposed to retain and position flashlight F for unobstructed use. In this headband configuration, the band 110 can be wrapped around and secured to the head of the user, or various other objects such as a tree trunk, or a vehicle sun-visor. An additional strip 125, preferably elastic, can be secured at the outside of the pocket strip 124 to define an additional support for a flashlight (such as one having a different shank size or shape) or a small tool, pen or pencil, etc. Alternatively, stitching can be set along the longitudinal centerline of the strip 125 to define two additional supports for small flashlights or tools.
With reference now to FIGS. 3 and 4, the band 110 will now be described as used in a storage configuration. The user folds the second end 114 of the band 110 over the strip 124 until the second end 114 overlaps the strip's first end 126. Preferably the resulting flap overlying the flashlight is pulled tight to engage the portion of the flashlight projecting from the pocket, to assist in retaining the flashlight in the pocket (the position of the upper portion of the flap is exaggerated in the drawings). The third negative 164b and the first positive connector 180a are then brought together and releasably engaged such that the portion of the first surface 120 of the band 110 between its second end 114 and the first end 126 of the strip 124 now defines an interior surface that overlies and protects the flashlight F held within the pocket.
The user then folds the first end 112 of the band 110 to a position proximate to the second end 128 of the strip 124, at the second surface 122 of the band. The first negative connector 160b and the second positive connector 182a are then brought together and releasably engaged such that the portion of the band 110 between its first end 112 and the second end 128 of the strip 124 form a closed loop. The assembly now forms a compact protective casing for the flashlight F, with no loose ends. However, the casing can be conveniently opened for access to the flashlight by disengaging the first positive connector 180a from the third negative connector 164b.
Still referring to FIGS. 3 and 4, the band 110 will now be described as used in a holster configuration. The holster configuration is substantially the same as the storage configuration except that the user threads the band 110 around a belt B to mount the holster. In the configuration shown in FIG. 3 and in solid lines in FIG. 4, belt B passes between the head of flashlight F projecting from its pocket and the first surface 120 of the band, immediately above the pocket-forming strip 124. Alternative locations for the belt to pass through the band 110 are shown in broken lines in FIG. 4. The solid line location is preferred because in this position the belt cooperates with the band 110 to retain the flashlight F in position. It should be understood that the user might choose to thread the belt through the band 110 instead of vice versa.
With reference now to FIG. 5, a first alternative embodiment of a headband in accordance with the present invention is illustrated generally at 200. The headband 200 is formed from an elongated band 210 having a first end 212, a second end 214 opposite the first end 212, opposite longitudinal edges, a first face 220 bounded by the first and second ends 212, 214 and the opposite longitudinal edges, and a second face 222 opposite the first face 220. The first and second ends 212, 214 may include first and second terminators.
A short pocket-forming strip of material 224 is affixed to a portion of the band 210 between its first end 212 and its second end 214 in the same manner as the previously described embodiment. The strip 224 has a first end 226, a second end 228 opposing the first end 226, and longitudinal margins joined to the first face 220 of the band to form a pocket for the flashlight F. The pocket opens along the second end 228 of the strip 224. The other end portion of the pocket, adjacent to the first end 226 can also be open but preferably is closed by being joined to the band.
At the first end 212 of the band 210 is a first negative connector 262b located on the second surface 222. A second negative connector 264b is attached to the outer side of the pocket-forming strip 224 toward its first end 226. At the second end 214 of the band 210 is a first positive connector 280a located on the first surface 220. A second positive connector 282a is attached to the second surface 222 of the band 210 between its first and second ends 212, 214 and toward the second end 228 of the strip 224.
The method of placing the first alternative band 210 into headband configuration will now be described. Without twisting the band 210 about its longitudinal axis, the user wraps the band 210 into a single loop such that the first end 212 and the second end 214 overlap, with the second end 214 on the inside. The first negative connector 262b and the first positive connector 280a are then brought together and releasably engaged such that the second surface 222 of the band 210 defines the interior surface of a substantially cylindrical shell and the first surface 220 of the band 210 defines the exterior surface of the substantially cylindrical shell. The pocket, being located on the first surface 220 of the band 210, is exposed at the exterior surface of the substantially cylindrical shell and thereby disposed to retain and position the flashlight F for unobstructed use.
With reference again to FIG. 5, the band 210 will now be described as used in a storage configuration. The user folds the second end 214 of the band 210 over the pocket-forming strip 224. The second negative connector 264a and the first positive connector 280b are then brought together and releasably engaged such that the portion of the first surface 220 of the band 210 between the second end 214 of the band 210 and the first end 226 of the strip 224 now defines an interior surface containing and protecting the flashlight F held within the pocket.
The user can then bring the first end 212 of the band 210 proximate to the second end 228 of the pocket-forming strip 224, but on the reverse side of the band. The first negative connector 262b and the second positive connector 282a are then brought together and releasably engaged such that the portion of the second surface 222 of the band 210 between the first end 212 of the band 210 and the second end 228 of the strip 224 continues to define an interior surface.
With reference still to FIG. 5, the band 210 will now be described as used in a holster configuration. The holster configuration is substantially the same as the storage configuration except that the user threads the band 210 around a belt B to mount the holster 200. Alternative locations for the belt to pass through the band 210 are indicated in broken lines. It should be understood that the user might choose to thread the belt through the band 210 instead of vice versa.
With reference now to FIG. 6, a second alternative embodiment of a headband is illustrated generally at 300. The headband 300 is formed from an elongated band 310 having a first end 312, a second end 314 opposite the first end 312, opposite longitudinal edges, a first face 320 bounded by the first and second ends 312, 314 and the longitudinal edges and a second face 322 opposite the first face 320. The first and second ends 312, 314 may include first and second terminators.
A pocket-forming strip of material 324 is affixed to a portion of the band 310 between its first end 312 and its second end 314. The strip 324 has a first end 326, a second end 328, and opposite longitudinal margins joined to the band as for the previously-described embodiments.
At the first end 312 of the band 310 is a first negative connector 362b located on the second surface 322. A second negative connector 364b is attached to the outside of the pocket-forming strip 324 toward the first end 326. At the second end 314 of the band 310 is a first positive connector 380a located on the first band surface 320 and a second positive connector 384a located on the second surface 322.
The method of placing the second alternative band 310 into headband configuration will now be described. Without twisting the band 310 about its longitudinal axis, the user wraps the band 310 into a loop such that the first end 312 and the second end 314 are proximate. The first negative connector 362b and the first positive connector 380a are then brought together and releasably engaged such that the second surface 322 of the band 310 defines the interior surface of a substantially cylindrical shell and the first surface 320 of the band 310 defines the exterior surface of the substantially cylindrical shell. The pocket 340, being adjacent to the first surface 320 of the band 310 opens at the exterior surface of the substantially cylindrical shell and thereby is disposed to retain and position the flashlight F for unobstructed use.
With reference again to FIG. 6, the band 310 will now be described as used in a storage configuration. The user brings the second end 314 of the band 310 proximate to the first end 326 of the pocket-forming strip 324. The second negative connector 364b and the first positive connector 380a are then brought together and releasably engaged such that the portion of the first surface 320 of the band 310 between the second end 314 of the band 310 and the first end 326 of the pocket-forming strip 324 now defines an interior surface containing and protecting the flashlight F held within the pocket.
The user then brings the first end 312 of the band 310 over the top of the second end 328 of the pocket-forming strip 324 and then proximate to the first end 326 of the strip 324. The first negative connector 362b and the second positive connector 384a are then brought together and releasably engaged such that the portion of the second surface 322 of the band 310 between the first end 312 of the band 310 and the first end 326 of the strip 324 continues to define an interior surface.
With reference still to FIG. 6, the band 310 will now be described as used in a holster configuration. The holster configuration is substantially the same as the storage configuration except that the user threads the band 310 around a belt B to mount the holster 300. Alternative locations for the belt to pass through the band 310 are indicated in broken lines. It should be understood that the user might choose to thread the belt through the band 310 instead of vice versa.
With reference now to FIG. 7, a third alternative embodiment of a headband is illustrated generally at 400. The headband 400, is formed from an elongated band 410 having a first end 412, a second end 414 opposing the first end 412, opposite longitudinal edges, a first face 420 bounded by the first and second ends 412, 414 and the opposite edges and a second face 422 opposite the first face 420. The first and second ends 412, 414 may include first and second terminators.
A pocket-forming strip of material 424 is affixed to a portion of the band 410 between its first end 412 and its second end 414 as for the previously-described embodiments. The pocket-forming strip 424 has a first end 426 and a second end 428. The resulting pocket is suitable for retaining and positioning a device such as a miniature flashlight F.
At the first end 412 of the band 410 is a first negative 460b located on the first surface 420 and a second negative connector 462b located on the second surface 422. A third negative connector 464b is attached to the outside of the pocket-forming strip 424 toward the first end 426. A fourth negative connector 466b is attached to the second surface 422 of the band 410 approximately midway between the first end 412 of the band 410 and the first end 426 of the strip 424.
At the second end 414 of the band 410 is a first positive connector 480a located on the first surface 420. A second positive connector 482a is attached to the second surface 422 of the band 410 at the second end 428 of the pocket-forming strip 424. A third positive connector 486a is connected to the first surface 420 of the band 410 proximate to the first end 426 of the strip 424.
The method of placing the third alternative band 410 into headband configuration (not shown), will now be described. Without twisting the band 410 about its longitudinal axis, the user wraps the band 410 into a loop such that the first end 412 and the second end 414 overlap. The second negative connector 462b and the first positive connector 480a are then brought together and releasably engaged such that the second surface 422 of the band 410 defines the interior surface of a substantially cylindrical shell and the first surface 420 of the band 410 defines the exterior surface of the substantially cylindrical shell. The pocket formed by strip 424 opens at the exterior surface of the substantially cylindrical shell and thereby is disposed to retain and position the flashlight F for unobstructed use.
With reference again to FIG. 7, the band 410 will now be described as used in a storage configuration. The user brings the second end 414 of the band 410 proximate to the first end 426 of the pocket-forming strip 424. The third negative connector 464b and the first positive connector 480a are then brought together and releasably engaged such that the portion of the first surface 420 of the band 410 between the second end 414 of the band 410 and the first end 426 of the pocket-forming strip 424 now defines an interior surface containing and protecting the flashlight F held within the pocket.
The user then folds the portion of the band 410 between the first end 412 of the band and the first end 426 of the strip 424 into an N-shaped pattern wherein the first surface 420 of the band 410 defines the interior of the first arch of the "N" while the second surface 422 of the band 410 defines the interior of the second arch of the "N". The fourth negative connector 466b and the second positive connector 482a are brought together and releasably engaged. The first negative connector 460b and the third positive connector 486a are then brought together and releasably engaged.
With reference still to FIG. 7, the band 410 will now be described as used in a holster configuration. The holster configuration is substantially the same as the storage configuration except that the user threads the band 410 around a belt B to mount the holster 400. Alternative locations for the belt to pass through the band 410 are indicated in broken lines. It should be understood that the user might choose to thread the belt through the band 410 instead of vice versa.
With reference now to FIG. 8, a fourth alternative embodiment of a headband is illustrated generally at 500. The headband 500 is formed from an elongated band 510 having a first end 512, a second end 514 opposite the first end 512, opposite longitudinal edges, a first face 520 bounded by the first and second ends 512, 514 and the longitudinal edges, and a second face 522 opposite the first face 520. The first and second ends 512, 514 may include first and second terminators.
A pocket-forming strip of material 524 is affixed to a portion of the band 510 at its first end 512 as described for the previous embodiments. The strip 524 has a first end 526 (preferably closed), and a second end 528 (open). The resulting pocket opens along the second end 528 of the strip 524. The pocket 540 is suitable for retaining and positioning a device such as a miniature flashlight F.
At the first end 512 of the band 510 is a first negative connector 562b located on the second surface 522 of the band 510. A second negative connector 564b is attached to the outside of the strip 524 toward its first end 526. A third negative connector 566b is located on the second surface 522 of the band 510, approximately midway between the first and second ends 512 and 514.
At the second end 514 of the band 510 is a first positive connector 580a located on the first surface 520 and a second positive connector 584a located on the second surface 522. A third positive connector 586a is affixed to the first surface 520 of the band 510, approximately midway between the first and second ends 512 and 514 and proximate to the third negative connector 566b.
The method of placing the fourth alternative band 510 into headband configuration will now be described. Without twisting the band 510 about its longitudinal axis, the user wraps the band 510 into a loop such that the first end 512 and the second end 514 overlap. The first negative connector 562b and the first positive connector 580a are then brought together and releasably engaged such that the second surface 522 of the band 510 defines the interior surface of a substantially cylindrical shell and the first surface 520 of the band 510 defines the exterior surface of the substantially cylindrical shell. The pocket opens at the exterior surface of the substantially cylindrical shell and is thereby disposed to retain and position the flashlight F for unobstructed use.
With reference again to FIG. 8, the band 510 will now be described as used in a storage configuration. The user brings the second end 514 of the band 510 over and around the second end 528 of the pocket-forming strip 524, around the first end 526 of the strip 524, and once again over and around the second end 528 of the strip 524 until the second end 514 of the band 510 is proximate the first end 526 of the strip 524. The second negative connector 564b and the third positive connector 586a are brought together and releasably engaged. The first positive connector 580a and the third negative connector 586b are then brought together and releasably engaged such that the first surface 520 of the band 510 is now at all points an interior surface, the portion between the second end 528 of the pocket-forming strip 524 and the third positive connector 586a containing and protecting the flashlight F held within the pocket.
With reference still to FIG. 8, the band 510 will now be described as used in a holster configuration. The holster configuration is substantially the same as the storage configuration except that the user threads the band 510 around a belt B to mount the holster 500. Alternative locations for the belt to pass through the band 510 are indicated in broken lines. It should be understood that the user might choose to thread the belt through the band 510 instead of vice versa.
With reference now to FIG. 9, a fifth alternative embodiment of a headband is illustrated generally at 600. The headband 600, is formed from an elongated band 610 having a first end 612, a second end 614, opposite longitudinal edges, a first face 620 bounded by the first and second ends 612, 614 and a second face 622 opposite the first face 620. The first and second ends 612, 614 may include first and second terminators.
A pocket-forming strip of material 624 is affixed to a portion of the band 610 at its first end 612. The strip 624 has a first end 626 (preferably closed), and a second end 628 (open). The strip 624 is affixed to the band as described for the prior embodiments. The resulting pocket is suitable for retaining and positioning a device such as a miniature flashlight F.
At the first end 612 of the band 610 is a first negative connector 662b located on the second surface 622 of the band 610. A second negative connector 664b is attached to the outside of the pocket-forming strip 624 toward its first end 626.
At the second end 614 of the band 610 is a first positive connector 680a located on the first surface 620 and a second positive connector 684a located on the second surface 622.
The method of placing the fifth alternative band 610 into headband configuration will now be described. Without twisting the band 610 about its longitudinal axis, the user wraps the band 610 into a loop such that the first end 612 and the second end 614 overlap. The first negative connector 662b and the second positive connector 684a are then brought together and releasably engaged such that the second surface 622 of the band 610 defines the interior surface of a substantially cylindrical shell and the first surface 620 of the band 610 defines the exterior surface of the substantially cylindrical shell. The pocket, being adjacent the first surface 620 of the band 610, opens at the exterior surface thereby is disposed to retain and position the flashlight F for unobstructed use.
With reference again to FIG. 9, the band 610 will now be described as used in a storage configuration. The user brings the second end 614 of the 610 over and around the second 628 of the pocket-forming strip 624. The second negative connector 664b and the first positive connector 680a are brought together and releasably engaged such that the first surface 620 of the band 610 is now at all points an interior surface, containing and protecting the flashlight F held within the pocket.
With reference still to FIG. 9, the 610 will now be described as used in a holster configuration. The holster configuration is substantially the same as the storage configuration except that the user threads the band 610 around a belt B to mount the holster 600. An alternative location for the belt to pass through the band 610 is indicated in broken lines. It should be understood that the user might choose to thread the belt through the band 610 instead of vice versa.
With reference now to FIG. 10, a sixth alternative embodiment of a headband is illustrated generally at 700. The headband 700, is formed from an elongated band 710 having a first end 712, a second end 714 opposite the first end 712, opposite longitudinal edges, a first face 720 bounded by the first and second ends 712, 714 and the edges and a second face 722 opposite the first face 720. The first and second ends 712, 714 may include first and second terminators.
A pocket-forming strip of material 724 is affixed to a portion of the band 710 at its second end 714 in the manner described above. The strip 724 has a first end 726 (preferably closed) and a second end 728 (open). The strip 724 is affixed to the band 710 as for the previously described embodiments. The pocket opens along the second end 728 of the strip 724, suitable for retaining and positioning a device such as a miniature flashlight F.
At the first end 712 of the band 710 is a first negative connector 760b located on the first surface 720 of the band 710 and a second negative connector 762b on the second surface 722 of the band 710. A third negative connector 766b is attached to the second surface 722 of the end 710 approximately one third of the length of the band 710 from the first end 712.
At the second end 714 of the band 710 is a first positive connector 782a located on the second surface 722. A second positive connector 788a is affixed to the first surface 734 of the strip 724 at its first end 726.
The method of placing the sixth alternative band 710 into headband configuration will now be described. Without twisting the band 710 about its longitudinal axis, the user wraps the band 710 into a loop such that the first end 712 and the second end 714 overlap. The first negative connector 760b and the first positive connector 782a are then brought together and releasably engaged such that the second surface 722 of the band 710 defines the interior surface of a substantially cylindrical shell and the first surface 720 of the band 710 defines the exterior surface of the substantially cylindrical shell. The pocket formed by strip 724 opens at the exterior surface of the substantially cylindrical shell and thereby is disposed to retain and position the flashlight F for unobstructed use.
With reference again to FIG. 10, the band 710 will now be described as used in a storage configuration. The user brings the first end 712 of the band 710 over and around the second end 728 of the pocket-forming strip 724 and down toward the first end 726 of the strip 724. The second negative connector 762b and the second positive connector 788a are then brought together and releasably engaged such that the first surface 720 of the band 710 between the second end 714 of the band 710 and the first end 726 of the strip 724 becomes an interior surface, containing and protecting the flashlight F held within the pocket against the second surface 722 of the band 710.
With reference still to FIG. 10, the band 710 will now be described as used in a holster configuration. The holster configuration is substantially the same as the storage configuration except that the user threads the band 710 around a belt B to mount the holster 700. Alternative locations for the belt to pass through the band 710 are indicated in broken lines. It should be understood that the user might choose to thread the belt through the band 710 instead of vice versa.
With reference now to FIG. 11, a seventh alternative embodiment of a headband is illustrated generally at 800. The headband 800 is formed from an elongated band 810 having a first end 812, a second end 814 opposing the first end 812, opposite longitudinal edges, a first face 820 bounded by the first and second ends 812, 814 and the edges and a second face 822 opposite the first face 820. The first and second ends 812, 814 may include first and second terminators.
A pocket-forming strip of material 824 is affixed to a portion of the band 810 at its first end 812. The strip 824 has a first end 826 (preferably closed) and, a second end 828 (open). The strip 824 is affixed to the band 810 as for the previously described embodiments. The resulting pocket opens along the second end 828 of the strip 824, suitable for retaining and positioning a device such as a miniature flashlight F.
At the first end 812 of the band 810 is a first negative connector 862b located on the second surface 822 of the band 810. A second negative connector 868b is attached to the first surface 820 of the band 810 approximately one third of the length of the band 810 from the first end 812.
At the second end 814 of the band 810 is a first positive connector 880a located on the first surface 820 and a second positive connector 884a located on the second surface 822. A third positive connector 889a is affixed to the second surface 822 of the band 810 approximately one third of the length of the band 810 from the second end 814.
The method of placing the seventh alternative band 810 into headband configuration, will now be described. Without twisting the band 810 about its longitudinal axis, the user wraps the band 810 into a loop such that the first end 812 and the second end 814 overlap. The first negative connector 862b and the first positive connector 880a are then brought together and releasably engaged such that the second surface 822 of the band 810 defines the interior surface of a substantially cylindrical shell and the first surface 820 of the band 810 defines the exterior surface of the substantially cylindrical shell. The pocket 840 opens at the exterior surface of the substantially cylindrical shell and is thereby disposed to retain and position the flashlight F for unobstructed use.
With reference again to FIG. 1 1, the band 810 will now be described as used in a storage configuration. The user brings the second end 814 of the band 810 under and around the first end 826 of the pocket-forming strip 824 and up toward the second end 828 of the strip 824. The third positive connector 889a and the first negative connector 862b are brought together and releasably engaged. The second negative connector 868b and the second positive connector 884a are then brought together and releasably engaged such that the first surface 820 of the band 810 between the first end 812 of the band 810 and the second negative connector 868b becomes an interior surface, containing and protecting the flashlight F held within the pocket against the second surface 822 of the band 810.
With reference still to FIG. 11, the band 810 will now be described as used in a holster configuration. The holster configuration is substantially the same as the storage configuration except that the user threads the band 810 around a belt B to mount the holster 800. Alternative locations for the belt to pass through the band 810 are shown in broken lines. It should be understood that the user might choose to thread the belt through the band 810 instead of vice versa.
Although a number of specific embodiments of the present invention have been described and illustrated, the present invention is not limited to the features of these embodiments, but includes all variations and modifications within the scope of the claims. Those skilled in the art will see many variations that fall within the spirit of the invention.
For example, all described embodiments exhibit a common general property. Each embodiment includes a band adapted to alternately occupy one of two states. In the first state, the band presents a single loop having an interior surface and an exterior surface. In the second state, at least a portion of the first state exterior surface is transformed into an interior surface. This general property allows a flashlight to be alternately exposed for use and protected for storage.
Although the bands described have been unitary which is preferred, this property is not absolutely necessary. The bands could be formed piecemeal from a series of elastic and inelastic panels. The bands could even be constructed of a plurality of substantially rigid panels that are flexibly connected together. Although the bands described have been planar and sheet-like, these geometries are again not necessary.
It should also be understood that the exact placement and arrangement of connectors is not crucial, so long as the arrangement selected allows the band to alternately occupy both the first state and the second state as described hereinabove. In particular, in the embodiments described, connectors were placed at the very ends of the bands so that loose ends did not exist.
Although the pocket is preferably constructed by lapping a strip of material over the band, other constructions are possible. Other containment means might include a free-standing pocket, a loop or a series of loops, ties, or metal or plastic hardware fasteners. Multiple pockets are contemplated. It is further contemplated that the interior surface of the pocket could include means for increasing the frictional forces between the pocket and the flashlight. Such friction increasing means might include lining or coating the pocket with rubber, grit, or other frictional materials.
It is also contemplated that the headband could hold objects other than a flashlight. Such other devices might include a bicycle mirror, a magnifying glass, or a transceiver.
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A headband for retaining and positioning an object is adapted to have an active configuration and an alternative passive configuration. In the active configuration, the headband can be made to encircle a user's head such that the object is retained on an exterior surface ready for use. In the passive configuration, the headband can be made to close around the object such that the object is retained on an interior surface, protected against damage, with the headband retained in a compact form. In this passive configuration, the headband can releasably engage a belt so as to form a holster for the object, thereby rendering both the object and the headband ready for rapid deployment.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from U.S. Provisional Application No. 60/674,976 filed Apr. 25, 2005, and is a continuation-in-part of U.S. application Ser. No. 11/411,489 filed Apr. 25, 2006, both by Gary Chouest, entitled Offshore Petroleum Discharge System, which are incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the transfer of liquids from a vessel offshore, to an onshore storage facility. More particularly, the present invention concerns a method and vessel for transferring large quantities of liquids, primarily refined hydrocarbons, from large tanker vessels offshore to onshore storage tanks using flexible pipe that can be rapidly deployed and recovered. The flexible pipe is heavier than the water that it displaces, and of small enough outside diameter such that it does not require anchoring in place on the sea floor.
2. Description of the Prior Art
The ability to transfer liquids from a vessel offshore to an onshore storage facility is known in the prior art. Systems typically include the installation of pipe on the sea floor, and the anchoring of that pipe in place, often by burying the pipe, or by covering it with heavy mats. These installations are designed to prevent the pipe from moving in the current, including severe currents that may be experienced in adverse weather conditions. Accordingly, these installations are often permanent and require substantial time to install. The piping cannot be easily retrieved for use at another site. If the pipe can be retrieved at all, it is at great expense and time investment.
Systems designed for rapid deployment of pipe have utilized pipe that is lighter than the sea water which the pipe displaces, such that the empty pipe floats when placed into the water. It is only when the pipe contains a liquid that the pipe, containing the liquid, is heavy enough to sink to the sea floor. Such systems, while providing the means to rapidly deploy the pipe, also required the pipe to be anchored on the sea floor. If not anchored, the pipe was too light to be resistant enough to the currents to remain in place. Systems that utilize such a “float/sink” deployment method require significant attention to anchoring, or simply cannot be used in adverse weather conditions. Additionally, deploying the pipe initially on the sea surface subjected the pipe and the attendant vessels and personnel to added risks when confronted with significant waves, winds, and tides.
Furthermore, systems requiring that a liquid be placed in the pipe to make the pipe heavy enough to sink create a potential liquid disposal problem and increase the risk of an environmental spill. Systems using sea water in the pipe in a “float/sink” deployment, may be confronted with a substantial quantity of contaminated sea water if the pipe still contains hydrocarbon residues from a prior use. Systems which utilize the liquid to be transferred (petroleum or other hydrocarbons) to give the pipe the required weight in a “float/sink” deployment, run the risk of a spill of that liquid during deployment, and the associated environmental hazards and clean up.
The prior art does not include a rapidly deployable and retrievable system for transferring liquid from an offshore vessel to an onshore storage facility that does not require anchoring of the retrievable piping system on the sea floor. The prior art also does not disclose a rapidly deployable and retrievable system for transferring liquids from an offshore vessel to an onshore storage facility that avoids the environmental hazards associated with systems that depend upon the weight of a liquid in the pipe during the deployment process.
SUMMARY OF THE INVENTION
The Offshore Petroleum Discharge System (OPDS) of the present invention provides a system that can be rapidly deployed and retrieved. The system utilizes a flexible pipe which is significantly heavier than the seawater which it displaces, even when empty. Such a piping system can be deployed when empty, sink to the sea floor, and remain in place even under adverse currents and tides. The flexible pipe is of small enough outside diameter, generally less than nine inches, such that it presents a low profile to currents. It is also flexible enough to have a bending radius of generally no greater than five feet. This facilitates the storage of the pipe on large spools onboard a vessel. The flexible pipe is strong enough to resist the strain of being pulled ashore by an onshore winch, and of being retrieved by a winch aboard the vessel containing the storage spools.
The primary vessel of the OPDS system is large enough to carry up to eight miles of flexible pipe. The flexible pipe is carried on large spools, each capable of carrying up to two miles of pipe. An extra spool facilitates deployment and retrieval of the pipe, as well as repair of any damaged segment. The vessel is dynamic positioning capable, such that it can hold position under adverse weather conditions, currents, and tides, while unloading a tanker and transferring liquid to the pipeline termination unit onshore. The vessel contains a holding tank for the liquid, and two pumps, each capable of pumping as much as 1,500 gallons per minute, delivering pressures of 5,000 psi.
The vessel also contains the equipment needed to establish a presence on the beach adjacent to a storage facility. This includes one or more amphibious vessels and the means to launch and retrieve those vessels; multi purpose tractor for use on the beach; a winch to pull the flexible pipe ashore; and a pipeline termination unit to receive and connect to the flexible pipe and to transfer the received liquid to the onshore storage facility. The vessel also contains the equipment needed to receive liquid from a tanker. This would include a holding tank for receiving the liquid and floating hose for connecting the holding tank to the tanker.
In practice, the primary vessel would arrive offshore of the area onshore requiring the delivery of liquid. The vessel is equipped with side scan sonar, such that the best route for the flexible pipe to the beach can be determined. The primary vessel would approach the ten meter curve, and launch one of the amphibious vehicles, containing the pipeline termination unit, winch, multipurpose tractor, and required personnel. The amphibious vehicle would pull a small messenger line from the primary vessel to the landing site. Once ashore, the multipurpose tractor would be used to prepare a suitable location for the pipeline termination unit and the winch. The messenger line would be attached to the winch, and a towline brought ashore. The tow line would be attached to the end of the flexible pipe. The flexible pipe would then be winched ashore, the pipe sinking as it enters the water, since it is heavier than the water it displaces.
Once ashore, the flexible pipe is connected to the pipeline termination unit, which is in turn connected to a liquid storage facility. The primary vessel then moves offshore from the ten meter curve, deploying flexible pipe as it goes, until it reaches the point where a tanker will be offloaded. The primary vessel can hold up to eight miles of flexible pipe in two mile segments. Once to the offloading point, the primary vessel will connect a buoy to the end of the flexible pipe such that the end of the flexible pipe can be easily recovered when the tanker is in position to be offloaded.
A tow line is connected to the tanker, and the tanker and primary vessel are maneuvered into position. The floating buoy and flexible pipe is retrieved and connected to the outlet of the pumping system aboard the primary vessel. The outlet manifold of the tanker is connected to the holding tank of the primary vessel using floating hose. The primary vessel is held in place using its dynamic positioning capabilities.
Under certain conditions a tender vessel may be needed to assist with positioning the tanker, and with other tasks. Once the tanker is connected to the holding tank of the primary vessel, and the end of the flexible pipe is connected to the pump on board the primary vessel, the pump in the tanker is used to transfer liquid from the tanker to the holding tank of the primary vessel. When sufficient liquid is aboard, the pump on the primary vessel is started, pumping liquid from the holding tank, through the flexible pipe, to the pipeline termination unit, and on to the storage facility ashore.
Once the transfer of liquid from the tanker is complete, another tanker can be brought into position, until the transfer of liquid at that location is no longer required. At that point, the flexible pipe is disconnected from the pipeline termination unit, and the winch on the primary vessel employed to retrieve the flexible pipe, rewinding it onto the pipe spools. The floating hose is retrieved and wound onto spools on the primary vessel. The amphibious vehicle collects the pipeline termination unit, multipurpose tractor, and winch, and returns to the primary vessel. The primary vessel is then ready to proceed to the next location needing the transfer of liquid from a tanker to an onshore location.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 of the drawings is the starboard side view of the primary vessel of the present invention.
FIG. 2 of the drawings is a cutaway illustration showing the layers of the flexible pipe of the present invention.
FIG. 3 of the drawings is a depiction of step one of the method of the present invention.
FIG. 4 of the drawings is a depiction of step two of the method of the present invention.
FIG. 5 of the drawings is a depiction of step three of the method of the present invention.
FIG. 6 of the drawings is a depiction of step four of the method of the present invention.
FIG. 7 of the drawings is a depiction of step five of the method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention uses a primary vessel ( 10 ) and a tender vessel ( 70 ). The primary vessel ( 10 ) may be a 348′×70′×28′ vessel, and the tender vessel ( 70 ) a 165′ fast supply vessel. Both vessels can operate on JP-5 fuel, eliminating the need to provide diesel fuel.
Primary vessel ( 10 ) has proven speed powering capabilities, and improved motion characteristics. Primary vessel ( 10 ) is dynamic positioning capable, classed by the American Bureau of Shipping with a DP-2 notation. The primary vessel ( 10 ) is powered with over 18,000 horsepower providing a speed over sixteen knots, fully laden in moderate weather (sea state 4 .) As shown in FIG. 1 , the primary vessel ( 10 ) is equipped with two tunnel thrusters ( 16 ), and a swing-down 360° Azimuthing thruster ( 18 ) forward, and two tunnel thrusters ( 20 ) and two main propulsion controllable pitch wheels ( 22 ) aft. Primary vessel ( 10 ) is capable of providing more than twice the amount of thrust required to hold a 50,000 deadweight ton tanker ( 40 ) in a forty knot wind, six feet waves, and three knot surface currents, while transferring 1.7 million gallons of jet propellant-5 (JP-5), or other liquids, per twenty hour workday from eight statute miles offshore.
The primary vessel ( 10 ) is equipped with the following:
Bow Loading System ( 26 ) with active swivel ( 62 ), quick disconnect ( 64 ), quick connect ( 64 ), and pig system ( 68 ) (including a pipe pig); Two pipeline termination units ( 50 ); Eight miles of flexible pipe ( 30 ), plus 1,000 feet armored section of flexible pipe, five deck ( 60 ) mounted storage reels or spools ( 12 ), stern chute and connecting table; Two thirty foot sections of flexible pipe ( 30 ) for repair purposes; Flotation for 6,000 feet of flexible pipe ( 30 ); Two 1,000 feet sections of 6″ ID float hose ( 46 ); Two float hose storage reels ( 24 );
In addition the primary vessel ( 10 ) may be equipped with some or all of the following:
Two Lighter Amphibious Response Cargo 15 Ton vehicles (LARC XV) (42) each equipped with a 50,000 to 60,000 pound winch; Two launching and recovery davits ( 14 ) for LARC XV ( 42 ); Two multipurpose tractors; Towing winch; Large rigid inflatable workboat and launch and recover davit; Two 1,500 GPM 5,000 psi transfer pumps ( 52 ), each driven with independent diesel power; Small vessel fueling station; Watermaker: capacity 30 tons per day and storage; Internal holding/transfer cargo tank ( 54 ); Flexible pipe anchors; Side scan sonar ( 66 ); Repair/workshop
Tender vessel ( 70 ) is a 165′ vessel capable of speeds in excess of twenty knots, a vessel that is able to work in shallow-draft areas assisting the primary vessel ( 10 ) in the deployment and retrieval of the flexible pipe ( 30 ), handling flotation and anchoring systems if required, as well as providing a stable platform for divers and storage for their gear, a vessel that may assist in the deployment of the float hose ( 46 ) to the tanker ( 40 ), as well as act as a tail tug for the tanker ( 40 ) when required. The tender vessel ( 70 ) will also be used for relieving beach crews, manning the Pipeline Termination Unit (PTU) (50) with a high-speed transit from the primary vessel ( 10 ) to shallow water, where its onboard rigid inflatable vessel will be used for exchanging personnel.
Tender vessel ( 70 ) will also be used to manage the flexible pipe ( 30 ) when installed, providing inspection services, repair services, and traffic control if required. Tender vessel ( 70 ) is equipped with 6,000 horsepower and a dropdown 360° Azimuthing bow thruster. The combination of primary vessel ( 10 ) and tender vessel ( 70 ) makes up a single eight mile system.
Primary vessel ( 10 ) and tender vessel ( 70 ) are maintained at a state-of-readiness with a full crew compliment on board and are capable of deployment to worldwide locations within twenty-four hours of notification. Once underway, vessels will maintain an average speed of sixteen knots in moderate weather (sea state 4 ) fully laden. Tender vessel ( 70 ) has a limited fuel range and may require refueling from primary vessel ( 10 ). In a full 10,000 mile voyage, considering refueling requirements, vessels will still maintain an average total trip speed of over thirteen knots.
Upon arrival at the site where liquids need to be transferred from a tanker ( 40 ) to an onshore storage facility, primary vessel ( 10 ) will establish communications and identify the beach landing point. If required, primary vessel ( 10 ) will run a side scan sonar track into the beach landing point to the ten meter curve verifying that the bottom is free from debris or hazards and select the best deployment path for the installation of the flexible pipe ( 30 ). As shown in FIG. 3 , during this procedure, the primary vessel ( 10 ) will launch an amphibious vehicle ( 42 ) carrying the multipurpose tractor and the pipeline termination unit ( 50 ). The amphibious vehicle ( 42 ) will receive a small messenger line ( 72 ) then proceed to the beach establishing the high-water mark where the PTU ( 50 ) will be offloaded and installed. The multipurpose tractor will construct the required berm around the PTU ( 50 ). The amphibious vehicle ( 42 ) will establish a position inland of the PTU ( 50 ), anchor itself with a beach anchor system, and commence recovery of the messenger line ( 72 ) using its onboard hydraulic winch. The messenger line ( 72 ) will bring ashore a soft towline, which will be attached to the end of the flexible pipe ( 30 ). Primary vessel ( 10 ) will then commence deployment of the flexible pipe ( 30 ) while maintaining station in dynamic positioning (DP) mode on the ten meter curve. At this point, dependant on the shore gradient and distance, primary vessel ( 10 ) can call upon tender vessel ( 70 ) to assist in pulling flexible pipe ( 30 ) into shallower waters. The flexible pipe ( 30 ) will be winched ashore. The flexible pipe ( 30 ) is designed to be deployed “sink/sink” unless the beach approach has heavy rocks or heavy coral, then there is the option to provide detachable floatation collars to deploy in a float/sink mode. The flexible pipe ( 30 ) has been designed with a double extruded external sheathing to increase its durability and has been designed to withstand a straight-line pulling of up to 351,762 pounds.
The flexible pipe ( 30 ) has an outside diameter as small as possible to limit its resistance to currents, and will generally be less than 9 inches, with a preferred embodiment having an outside diameter of 8.11 inches. The resistance of the flexible pipe ( 30 ) in sand or mud is relatively small. The flexible pipe ( 30 ) is heavier than the water it displaces, even when empty. A preferred embodiment of the flexible pipe ( 30 ) weighs 36.30 pounds per foot, and provides negative buoyancy in seawater of 13.62 pounds per foot empty. The flexible pipe ( 30 ) has been designed to eliminate the need to anchor the line during or after deployment. The flexible pipe ( 30 ) has been designed to provide for an easy, efficient installation, even with a three knot surface current and forty knot wind in six foot seas. The flexible pipe ( 30 ) has been designed to be installed empty and dry and will self bury. Installation of the flexible pipe ( 30 ) empty eliminates the creation of waste water after deployment.
Once the flexible pipe ( 30 ) has been winched to the PTU ( 50 ) unit, connection will be made. As depicted in FIGS. 4 and 5 , primary vessel ( 10 ) will get underway and continue deploying the flexible pipe ( 30 ) to the ocean floor at a rate of deployment of 0.3 miles per hour, until the primary vessel ( 10 ) reaches the offloading point. Flexible pipe ( 30 ) is made up of two mile segments. If the full eight miles is not required, shorter horizontal distances can be achieved by using fewer segments. For example, if only five miles is required, then six miles of flexible pipe ( 30 ) will be deployed and at the five mile offloading point, the flexible pipe ( 30 ) will be laid in a loop. Primary vessel ( 10 ) will attach a surface buoy ( 44 ) and a messenger line to the end of the flexible pipe ( 30 ) and drop it to the ocean floor. Primary vessel ( 10 ) then proceeds to rendezvous with the tanker ( 40 ), passes a messenger line and a hawser ( 48 ) to the bow of the tanker ( 40 ), and proceeds with the tanker ( 40 ) to the offloading point. Tender vessel ( 70 ) attaches a stem line ( 49 ) to the tanker ( 40 ), as shown in FIG. 7 , to assist primary vessel ( 10 ). Primary vessel ( 10 ) will recover the soft buoy ( 44 ) with a grappling hook or if required utilize its rigid inflatable workboat or tender vessel ( 70 ) to assist in the recovery of the soft buoy ( 44 ). Once the soft buoy ( 44 ) has been retrieved, the messenger line will be fed to the bow loading system ( 26 ), and recover the end of the flexible pipe ( 30 ) into the bow loading system ( 26 ). It will be automatically connected with the quick connect system to the cargo discharge piping. Flexible pipe ( 30 ) will undergo a pigging operation originating from the primary vessel ( 10 ). The pig will be recovered at the PTU ( 50 ). The flexible pipe ( 30 ) has been deployed empty and dry. Whether the method of deployment was sink/sink or float/sink (using floatation collars on the flexible pipe ( 30 )), the deployment generates no waste water, and the pigging operation is used as a safety integrity check.
Simultaneous to this operation, primary vessel ( 10 ) deploys a float hose ( 46 ) from its stern to mid-ship area of the tanker ( 40 ) assisted by either the tender vessel ( 70 ) or a rigid inflatable workboat. Tanker ( 40 ) will connect float hose ( 46 ) to its discharge manifold and under orders from the captain of the primary vessel ( 10 ), tanker ( 40 ) will commence offloading. Liquid cargo will be offloaded into a holding/transfer tank ( 54 ) on primary vessel ( 10 ) and then transferred via high-pressure transfer pumps ( 52 ) through the flexible pipe ( 30 ) to the PTU ( 50 ) at a rate of 1.7 million gallons per twenty hour period with an output pressure at the PTU ( 50 ) between 50 and 125 psig. The entire deployment operation can be completed in less than forty-eight hours.
Primary vessel ( 10 ) will maintain its position over the offloading point utilizing its dynamic positioning (DP) capability. Where phenomenon known as surging and fishtailing occurs, which sometimes results from two different size, different draft hulls being tied in close proximity, the tender vessel ( 70 ) will be attached to the stern of the tanker ( 40 ), if required, maintaining the tanker in a weathervane position behind primary vessel ( 10 ).
When offloading is complete, primary vessel ( 10 ) will release flexible pipe ( 30 ) to the ocean floor with soft buoy ( 44 ) attached. Float hoses ( 46 ) from the tanker ( 40 ) will be recovered. Tanker hawser ( 48 ) will be released. Tender vessel ( 70 ) will be released. Primary vessel ( 10 ) will rendezvous with next offloading tanker ( 40 ) and repeat procedure.
Once operations have been completed and it is desired to retrieve the system, primary vessel ( 10 ) will pig the flexible pipe ( 30 ) insuring that it is once again empty, disconnect the flexible pipe ( 30 ) from the PTU ( 50 ) and its discharge line, pass the messenger line across the stern of the primary vessel ( 10 ), and will commence retrieving the flexible pipe ( 30 ) onto its powered storage reels or spools ( 12 ).
Simultaneously, the PTU ( 50 ) will be disconnected and loaded on board the amphibious vehicle ( 42 ). The multipurpose tractor will be loaded on board the amphibious vehicle ( 42 ). The amphibious vehicle ( 42 ) and personnel will be returned and loaded on board the primary vessel ( 10 ).
When flexible pipe ( 30 ) retrieval is completed, primary vessel ( 10 ) and tender vessel ( 70 ) will get underway to the next destination. The total retrieval process will be completed in less than seventy-two hours and can be accomplished in an environment of forty knot winds, six foot waves, and three knot surface currents. The OPDS system, primary vessel ( 10 ), and tender vessel ( 70 ) will survive in fifty-five knot winds, twelve foot waves, and five knot surface currents over a seventy-two hour period.
The Offshore Petroleum Discharge System (OPDS) combines various components to achieve liquid delivery in a quick, safe, environmentally responsible manner. One of the key components is flexible pipe ( 30 ). The flexible pipe ( 30 ) provides a viable deployment method that comprises environmentally sound loading and landing of the flexible pipe ( 30 ) ashore. The flexible pipe ( 30 ) is deployed “sink/sink,” which allows for installation in up to three knot currents, forty knot winds, and six foot waves; survival in up to five knot currents, fifty five knot winds, and twelve foot waves; provides for deployment up to eight statute miles offshore; and provides for installation in forty-eight hours and retrieval in seventy-two hours.
The flexible pipe ( 30 ) with a preferred embodiment having outside diameter of 8.11 inches is a cost effective alternative to complicated and diver installed anchoring systems. This outside diameter minimizes the current loads imposed on the flexible pipe ( 30 ) keeping it stable in all but the most severe current and surf conditions. Anchoring systems may still be provided on an as required basis.
The flexible pipe ( 30 ), such as that manufactured by Technip, has been used in the offshore exploration and production industry. It is designed in accordance with API17J “Specification for Unbonded Flexible Pipe.” The flexible pipe ( 30 ) is negatively buoyant to ensure pipeline seafloor stability in extremely high cross currents, three knot installation, and five knot survival. Unlike a float/sink pipeline, which must float into place empty and be sunk by filling with either product or seawater, a sink/sink pipeline is heavy enough on the bottom (empty) to survive the specified currents without the need for excessive anchoring. Limited or no anchoring will require only minimal or no diver support.
An added benefit of the sink/sink deployment scheme is that no ballast is required for the flexible pipe ( 30 ) deployment. The flexible pipe ( 30 ) sinks under its own weight. The flexible pipe ( 30 ) endfittings can fully seal the end of the flexible pipe ( 30 ), allowing for external leak testing prior to the flexible pipe ( 30 ) being sunk to the seafloor. This mitigates against spills in accordance with best environmental practices used in the offshore field today. The flexible pipe ( 30 ), once installed, will have been leak tested and is empty, contributing minimal wastewater requiring handling and disposal. If completely flooded, the entire eight statute mile flexible pipe ( 30 ), with an inside diameter of 5.7 inches, will contain approximately 50,000 gallons. With minimal connections being made and tested by trained personnel in accordance with best marine practice, the system is installed without the risk of a spill.
The flexible pipe ( 30 ) can be repaired on board the primary vessel ( 10 ). The primary vessel ( 10 ) is equipped with repair endfittings, installable within twenty-four hours. The repair endfitting is capable of sustaining all internal pressure and tensile loadings as the original endfitting. The size of the repair endfitting, and the need to service the endfittings on the storage reels ( 12 ), is such that the repaired section will be removed to and stored on the additional reel ( 12 ). If a section of the flexible pipe ( 30 ) needs to be moved about the primary vessel ( 10 ) for servicing or inspection, it can be moved to and from the primary vessel's vertical powered storage reel ( 12 ). This allows the system to be completely self sufficient and not dependent on significant shore based resources.
The management of static electricity is a concern in the flexible pipe ( 30 ). Non-conductive surfaces affect the rates of charge generation and charge dissipation during flow through a pipe. The rate of charge generation is similar in conductive and non-conductive pipes, while the rate of charge lost can be significantly slower in non-conductive pipes. For charged non-conductive liquids (such as JP-5) insulation by the pipe wall can result in charge accumulation of the opposite polarity on the outer surface of the insulating liner or pipe. Charge accumulation can eventually lead to electrical breakdown and pinhole punctures of either the liner or, in the case of non-conductive pipe, the entire wall thickness.
The flexible pipe ( 30 ) is comprised of nine layers as shown in FIG. 2 . The outer layer is a TPE protective sheath ( 31 ). The next layer is KEVLAR fabric tape ( 32 ); the next layer a polyethylene sheath ( 33 ); inside of the polyethelene sheath ( 33 ) is another layer of KEVLAR fabric tape ( 34 ); followed by an outside armor layer ( 35 ), and an inside armor layer ( 36 ); a layer of “zeta wire” ( 37 ) (as made by Technip); followed by a layer of Rilsan pressure sheath ( 38 ); with a final interlocked stainless steel carcass ( 39 ) inside layer.
The accumulation of static electricity eventually could cause damage to the Rilsan pressure sheath ( 38 ). However, the stainless steel interlocked carcass ( 39 ) is conductive and will be electronically connected to the flexible pipe ( 30 ) endfitting, which is made of carbon steel and is grounded by contact with sea water. The charge separation still occurs between the fluid and the carcass ( 39 ). But since the carcass ( 39 ) is electrically connected to the grounded endfittings, the electrical charge will evacuate into the sea and accumulation is impossible.
The interlocked carcass ( 39 ) is not leak proof and some fluid, such as JP-5, will be in contact with the non-conductive Rilsan pressure sheath ( 38 ); however, no charge is anticipated to accumulate into the pressure sheath ( 38 ) since the fluid in contact with the pressure sheath ( 38 ) will be stagnant, the stainless carcass ( 39 ) will be grounded and will act as a grillage eliminating the charge of any fluid passing through it, and the inner surface of the Rilsan pressure sheath ( 38 ) will be in contact with the stainless steel carcass ( 39 ) and any charge created in the pressure sheath ( 38 ) will be evacuated by the stainless steel carcass ( 39 ). Accordingly, the stainless steel carcass ( 39 ) will protect the Rilsan pressure sheath ( 38 ) from having accumulation of electrical charges.
This flexible pipe ( 30 ) can be installed within forty-eight hours of the vessel arrival on location, and is very robust. The flexible pipe ( 30 ) can be installed on various soils such as sand, mud, rocks, or coral. Accordingly, there will be only a few hours allocated for survey of the seabed. The flexible pipe ( 30 ) has, in addition to the standard polyethylene external sheath ( 33 ), a reinforced protective sheath made of thermoplastic elastomer (TPE) ( 31 ). Both sheaths will be separated by a layers of KEVLAR tape ( 32 and 34 ). The TPE protective sheath ( 31 ) has a superior resistance to abrasion and the KEVLAR tape layer ( 32 ) will mechanically reinforce the external sheath and protect it, should any local hazard damage it.
The flexible pipe ( 30 ) will be suitable for twenty plus years of service life. The flexible pipe ( 30 ) length may vary from any length up to eight miles. Also, should the flexible pipe ( 30 ) be damaged locally, the system shall be versatile enough to continue the operation while repairing the line. It is therefore more adequate to have a flexible pipe ( 30 ) with a limited number of sections that are connected together during the deployment operation. Should a section be damaged locally, another section will be laid while the damaged section is repaired using the deck mounted vertical powered storage reel ( 12 ).
During recovery, a visual inspection of the line is sufficient to detect any defect in the outer sheath ( 31 ). In addition, the water tightness of the external sheath ( 31 ) can be checked by vacuum tests while the flexible pipe ( 30 ) is packed on the reels ( 12 ). Should any defect be detected, repair procedures can be performed. In case of local damage, the flexible pipe ( 30 ) can be easily repaired. If the external sheath ( 31 ) is damaged, a new plastic patch can be “welded” to the plastic. This plastic patch is waterproof. If further layers of the flexible pipe ( 30 ) are damaged, the line can be cut and two new end fittings can be mounted on the extremities. Both repair procedures can be done offshore and the provision of the deck mounted storage reel ( 12 ) will allow completion of the repair with the minimum disturbance to operations.
Flexible pipe ( 30 ) specifications for a preferred embodiment are:
Characteristics
Imperial
Metric
Diameter:
Inside
5.70
in
144.80
mm
Outside
8.11
in
206.10
mm
Weight:
In air empty
36.30
lbf/ft
54.46
kgf/m
In sea water empty
13.62
lbf/ft
20.27
kgf/m
Pressure:
Nominal bursting
10587
psi
730
bars
Hydrostatic collapse
1406
psi
97
bars
Damaging Pull:
In straight line
351762
lbf
1564.72
kN
Minimum
For storage
4.40
ft
1.34
m
Bending Radius
Tanker ( 40 ) will be offloaded utilizing tanker's discharge pumping system ( 56 ) typically providing 100 psi at the tanker ( 40 ) rail. Liquid cargo will be moved via 6″ ID floating hose ( 46 ) into the primary vessel ( 10 ) holding/transfer tanks ( 54 ). The holding/transfer tank ( 54 ) will utilize automated valving integrated into a digital control system comprised of high level and low level liquid level alarms. Levels will be monitored both locally, the tank location and the primary vessel's ( 10 ) bridge/control center with automated valve control and electrostatic discharge (ESD) capabilities at each location.
Constant transfer tank liquid level will be maintained by a pneumatically actuated control valve located on the inlet side of the transfer tank. A small primer pump will move cargo from the holding/transfer tank to the main transfer pump, which is a dual casing “barrel” pump, multi-stage, centrifugal. All centrifugal pumps are designed to be operated in a certain range of their performance curve. Operation beyond a certain maximum flowrate, or below a certain minimum flowrate is detrimental to the pump and will reduce its life. Initial startup may be with an empty discharge line, such that the pump will try to produce flows in excess of the recommended maximum until the line fills and back pressure reduce the flowrate. Alternately, if the discharge pressure becomes excessive for any reason (blockage in the line, closed discharge valve, etc.), damage can occur from the flowrate being below the minimum recommended flowrate. For these reasons, a discharge control valve ( 58 ) is utilized.
On initial startup (pipeline empty) when energized, the valve ( 58 ) will sense low system pressure in the pipeline and partially close the valve to maintain operation of the pump in its acceptable operation range relative to its performance curve. The approximate minimum discharge pressure for satisfactory operation of the pump is 4500 psig. The valve will hold the design pressure at the design condition of 5000 psig (1500 GPM) and hold there until pressure equalizes. At the point where the pipeline pressure equals the pump design pressure, the valve will remain in that setting position until its senses change in the pipeline pressure. If the pipeline pressure goes down during operation due to reduced friction losses (the primary vessel ( 10 ) moves closer to shore for example), the valve will again begin to close to impose the artificial design pressure of 5000 psig. In the case where the pipeline pressure increases for any reason above the design pressure (blockage in the line or increased friction losses due to increased distance from shore), the valve will open to allow more flow and reduced pressure until it reaches “full open” position.
A by-pass control valve will also be installed. If the discharge pressure continues to rise higher than the acceptable minimum flow for the pump (maximum pressure), then the by-pass valve will sense this pressure and begin to open allowing flow to go back to the holding tanks relieving the pressure on the pump and allowing it to operate in its acceptable operating range. As the discharge pressure reduces, the by-pass valve will begin to close until pump reaches its acceptable operating range and the discharge control valve will again take over control of the system.
Primary vessel ( 10 ) is equipped with two complete transfer pumps, each with its own independent diesel engine. One will act as primary, one will be backup. Each pump will be capable of transferring cargo at a rate of 1.7 million gallons per twenty hour day from a distance of up to eight miles.
Primary vessel ( 10 ) will be equipped with two amphibious vehicles ( 42 ), such as a LARC XV, to support the beach terminus requirement. The LARC XV is an excellent amphibian to work an environment of forty knot winds, six foot waves, and three knot surface current both in the water and ashore. The LARC XV amphibian's winch and other logistics are readily available in the U.S. market.
The LARC XV amphibian characteristics are:
LARC XV
Weight (dry):
45,000 lbs
Weight (fully loaded):
75,000 lbs
Cargo bay:
23′11″ × 11′11/25″
Overall length:
45′
Overall width:
14′8″
Overall height:
15′4″
Ramp width:
9′
Ramp capacity:
9,000 lbs
Hull material:
Aluminum
Cargo Space:
45′ × 15′
Weight capacity:
15 tons
Power:
Two (2) 300 HP Cummins Diesel
To provide the necessary beach OPDS interface to the receiving services, the LARC XV amphibious vehicle ( 42 ) is embarked on primary vessel ( 10 ). The amphibious vehicle ( 42 ) will deploy from the primary vessel ( 10 ) to the designated PTU ( 50 ) site. The amphibious vehicle ( 42 ) has a robust power ramp to allow the deployment of the multipurpose tractor and PTU ( 50 ), with PTU ( 50 ) hook up hardware and beach anchoring system
The multipurpose tractor has a capacity to provide multipurpose front digging blade, forklift tines, backhoe, and other capacity features. The tractor will be embarked within the amphibious vehicle ( 42 ) and deployed from the amphibious vehicle ( 42 ) upon landing on the designated beach. The multipurpose tractor will move the PTU ( 50 ), the PTU ( 50 ) hookup equipment and anchoring systems. These items will be positioned for deployment using the multipurpose tractor.
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A method and associated vessel for transferring liquids from offshore tankers to an onshore storage facility. The system utilizes a flexible pipe that is heavier than the water it displaces, such that the flexible pipe sinks to the sea floor even when empty. The high weight and relatively small profile of the flexible pipe avoids the need for anchoring the pipe to the sea floor. The flexible pipe has a bending radius of no greater than five feet, such that it can be wound onto spools onboard the vessel, and can be rapidly deployed, retrieved, and reused in another location. The vessel containing the spools of flexible pipe is dynamic positioning capable, and contains the equipment required to establish a position onshore to receive the liquid being transferred; means to deploy, retrieve, and repair the flexible pipe; and means to receive liquid from a tanker vessel and pump that liquid through the flexible pipe to the onshore storage facility.
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FIELD OF THE INVENTION
The present invention relates in general to television systems and in particular to video highlight attenuation processors for television camera monitors.
BACKGROUND OF THE INVENTION
There are three types of "blooming" which occur in television systems. One type is "spot" blooming, which results from the brightness and contrast controls of the television receiver or monitor being improperly set such that the receiver or monitor does not operate within the linear region of the camera.
Another type of blooming, associated with receivers, is caused by atmospheric conditions or man-made disturbances, usually of a temporary nature.
The present invention concerns the third type of blooming, and this type is caused by bright lights within the televised scene. Blooming of this type results from the inability of the electron beam in the camera to neutralize completely the affected area of the target. When this type of blooming effect occurs, the scene as viewed on a monitor appears to be washed out. Further, when bright areas appear within the scene, they are very distracting to the viewer. The net result in both cases is a loss of information within and adjacent to the affected areas.
Various mechanical methods have been used in the prior art to overcome the scene-related type of blooming. For example, one of these methods involves the use of a motorized iris within the lens, while another method uses a motorized filter wheel. Such mechanical methods have a major disadvantage in that, although they do attenuate the bright areas, they also attenuate the scene around the affected areas.
Electronic circuits have also been employed in the prior art to compensate for the various types of blooming noted above. Examples of such circuits are disclosed in U.S. Pat. Nos. 2,414,228 (Gottier); 2,978,537 (Kruse et al.); and 3,179,743 (Ahrons). The Gottier circuit employs a blocking diode to clip the white peaks of the video signal above a preset level to reduce blooming. A disadvantage of this type of circuit is that any information within the bright area is completely lost. Although this loss of information can be tolerated in a home television receiver, such loss cannot be tolerated in more demanding applications, such as, for example, a military environment.
The Kruse et al. circuit uses an averaging technique to produce a direct current (D.C.) voltage, the amplitude of which is an inverse function of the average peak-to-peak value of the video signal over a pre-determined time period, for controlling or serving as the supply voltage for one or more of the camera tube electrodes. This method of control has the disadvantage of affecting the overall picture and not just the high peaks of the signal which produce the blooming effect. The Kruse et al. method of control has the further disadvantage of introducing a time delay in the circuit because of the closed loop configuration which is employed.
The Ahrons circuit is directed to control of spot blooming resulting from the contrast control being set too high, and employs for this purpose two diodes by which the white peaks which would cause blooming are separated from the rest of the video signal. The separated white peak signals are then amplified to provide a D.C. control signal which is used to control the AGC voltage so as to decrease the overall set gain. The Ahrons circuit thus suffers from the same disadvantage as does the Kruse et al. circuit.
Electronic circuits are also known in the prior art which compensate for noise pulses. An example of such a circuit as employed in a television receiver is disclosed in U.S. Pat. No. 2,424,349 (Cawein). The Cawein circuit eliminates random rate noise pulses resulting from atmospheric or man-made disturbances which can cause instability in the video and sync circuits of a receiver. This purpose is achieved in the Cawein circuit by demodulating the carrier wave to separate out noise currents having intensities in excess of a predetermined level, inverting the demodulated noise signal, and combining the inverted signal with the carrier wave to eliminate the demodulated noise signals therefrom. The Cawein circuit would be inappropriate for use in controlling scene-related blooming, since any information in the demodulated signals representing the bright areas would be lost by the cancelling effect produced by the Cawein circuit.
SUMMARY OF THE INVENTION
These and other disadvantages of the prior art are overcome by the video highlight attenuation processor of the present invention, wherein two signals corresponding to an input video signal are derived by an input circuit, the peak portions of one of the derived signals having an amplitude greater than a predetermined maximum are detected and inverted by a peak detecting and inverting circuit to produce an intermediate signal, and the intermediate signal and the other of the derived signals are combined by a combining circuit such that an output signal is produced which corresponds to the input video signal with the D.C. level of the peak portions attenuated.
In accordance with a further aspect of the invention, the detecting and inverting circuit comprises an emitter-follower transistor amplifier, a voltage dividing network, which is preferably variable, and a zener diode connected between the emitter of the amplifier and the voltage dividing network.
In accordance with a still further aspect of the invention, the combining circuit comprises a summing junction to which the collector of the amplifier and the non-detected signal are connected.
Other features and advantages of the invention will be set forth in, or apparent from, the detailed description of a preferred embodiment found herein below.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic circuit diagram of a video highlight attenuation processor constructed in accordance with the present invention;
FIG. 2 is a graphic depiction of a typical composite video signal produced by a TV camera viewing a scene having bright spots therein; and
FIGS. 2(a) and 2(b) are graphic depictions of the waveforms of the signals at two different points in the circuit of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a video highlight attenuation processor constructed in accordance with the present invention generally comprises input circuitry, generally denoted 10, for deriving from an incoming video signal V IN two duplicate signals V IN1 and V IN2 , respectively, which are equivalent to signal V IN ; a peak signal detecting and inverting circuit, generally denoted 20, for detecting positive going peak portions of signal V IN1 which have an amplitude greater than a predetermined maximum, and for inverting the detected peak signals to produce corresponding signals V INV , a mixer 50 for combining signals V INV with signal V IN2 so as to produce a signal V O which corresponds to input signal V IN with the D.C. level of the detected positive peak portions attenuated or removed; an amplifier circuit 60 for providing a low impedance output drive signal V OUT for a television monitor (not shown); and a power supply 70.
Input circuitry 10 advantageously comprises a resistive network comprising resistors R1 and R2 and a coupling capacitor C1 connected as shown. Exemplary values of resistors R1 and R2 are 27 ohms and 150 ohms, respectively, and an exemplary value of capacitor C1 as 10 microfarads (MFD).
Detecting and inverting circuit 20 comprises a transistor Q1 and a bypass capacitor C3 and biasing resistors R3, R4, R5, and R6 connecting transistor Q1 to power supply 70, as shown, so as to constitute an emitter follower amplifier; a resistor R7 and a potentiometer P1 connected as a voltage dividing network across power supply 70, as shown; and a zener diode D1 connected between the variable input of potentiometer P1 and the junction defined by resistor R6 and the emitter of transistor Q1, as shown. Adjustment of potentiometer P1 determines both the amplitude at which detection occurs and the amplitude of the inverted signal V INV .
In a specific exemplary embodiment, transistor Q1 is a 2N2219 type transistor; resistors R3, R4, R5, R6 and R7 have values of 220K ohms, 10K ohms, 4.7K ohms, 60 ohms, and 220 ohms, respectively; capacitor C3 has a value of 100 MFD; potentiometer P1 has a value of 1K ohms; and diode D1 is a IN747A type diode.
In the preferred embodiment illustrated, mixer 50 is constituted by a summing junction. The output V INV , which is produced at the collector of transistor Q1, is connected to mixer 50 by a coupling capacitor C2 and resistor R8, as shown. Exemplary values of capacitor C2 and resistor R8 are 10 MFD and 330 ohms, respectively.
The output V O of mixer 50 is connected, as shown, to the input of amplifier circuit 60 by a coupling capacitor C4, a preferred value of which is 10 MFD.
Amplifier circuit 60 advantageously is a conventional emitter follower amplifier comprising a transistor Q2; biasing resistors R9, R10, and R11 connected between transistor Q2 and power supply 70, as shown; and a coupling network comprising resistors R12 and R13, and a capacitor C5 connected as shown to the emitter of transistor Q2. Exemplary values of resistors R9, R10, R11, R12, and R13 are 1.5K ohms, 5.6K ohms, 330 ohms, 560 ohms, and 100 ohms, respectively. An exemplary value of capacitor C5 is 100 MFD, and transistor Q2 preferably is a 2N2219 type transistor.
A double-pole, double-throw switch S1 may also advantageously be provided, as shown, to which the input signal V IN and the output V OUT produced by the processor are connected such that either the unprocessed composite video signal from the television camera, or the highlight attenuated video signal produced by the processor of the present invention may be selectively fed to a monitor. As shown, a load resistor R14, which has an exemplary value of 100 ohms, may be provided between the pole of switch S1 to which signal V IN is connected and ground.
Typical waveforms illustrating the effect of a processor constructed in accordance with the present invention are shown in FIGS. 2 to 2(b). In FIG. 2, a composite video signal is depicted which is typically produced by a television camera viewing a scene having brightly lit areas therein. The portions of the scene which are lit by the ambient light levels are represented by the portions of the waveform denoted 80, and a brightly lit portion of the scene is represented by the peak portion of the waveform denoted 82.
The output V INV produced by peak detecting and inverting circuit 20 is shown in FIG. 2(a), and the combined signal produced at summing junction 50 is shown in FIG. 2(b). As shown, the effect of the processor of the invention is to attenuate the detected peak portions 80 of the incoming signal so as to remove the D.C. components thereof, while retaining the video information contained therein. Glare and blooming are eliminated without otherwise distorting the information within the scene areas giving rise to the glare and blooming problems. In addition, the absence of closed loops and rectification of the incoming signal avoids the introduction of any delays into the processed video signal.
Although the invention has been described with respect to an exemplary embodiment thereof, it will be understood that variations and modifications can be effected in the embodiment without departing from the scope or spirit of the invention.
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A video highlight attenuation processor is disclosed which comprises an it circuit from which first and second signals corresponding to an input signal are derived, a peak detecting and inverting circuit which detects and inverts peak portions of the first signal to produce an intermediate signal, and a mixer which combines the intermediate signal and the second signal such that an output signal is produced which corresponds to the input signal with the D.C. level of the peak portions attenuated.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/169,418, by Bahl, entitled “Channel Access Scheme For Use In Network Communications,” filed on Oct. 9, 1998, which is hereby incorporated by reference in its entirety as of the filing date of this application.
FIELD OF THE INVENTION
[0002] This invention relates generally to communication networks and, more particularly, relates to a channel access scheme for use in transmitting information over a wireless communication network.
BACKGROUND OF THE INVENTION
[0003] In communication networks, the communication channel is a precious resource that needs to be shared intelligently between multiple communication sources. To efficiently utilize this resource, an appropriate channel access scheme must be selected. The target application and the corresponding underlying traffic that is envisioned to traverse the communication network largely influence this selection. Typically, the underlying traffic is envisioned to be integrated packet voice and data communications. Accordingly, currently utilized channel access schemes are biased towards supporting integrated packet voice and data communications while packet video communication is generally ignored.
[0004] For supporting integrated packet voice and data communications, several multiple access schemes have been proposed in the prior art. Specifically, these schemes can be organized into three well known categories, namely, Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), and Code Division Multiple Access (CDMA). Among these three schemes, schemes based on TDMA, where time is divided into frames and frames are divided into slots, have enjoyed the most acceptances.
[0005] Generally, in TDMA schemes, a communication source transmits a transmission packet over the communication channel upon the commencement of its assigned time slot. A network router, in the form of a base station, server, or the like, receives the transmission packet and then assists in routing the transmission packet towards its final destination. Depending on which time-slots are assigned to the communication source, TDMA schemes are classified into two types: basic TDMA and dynamic TDMA. In basic TDMA, specific time-slots are assigned to the communication source for the entire duration of the connection. In contrast, in dynamic TDMA, the specific time-slots assigned to the communication source can vary during the lifetime of the connection. Dynamic TDMA schemes are essentially a compromise between random access and controlled access type protocols. These schemes contain at least one contention phase in which new communication sources attempt to announce their presence by transmitting connection establishment request messages to the network router. Examples of such TDMA based schemes include Packet Reservation Multiple Access (PRMA), Reservation-ALOHA and Reservation-MA (R-MA), Dynamic Reservation Multiple Access (DRMA), and Dynamic-Time Division Multiple Access (D-TDMA). The frame structures used in PRMA, R-MA, DRMA, and D-TDMA are each illustrated in prior art FIG. 1.
[0006] Turning first to the frame structure utilized with PRMA, a slot S within a frame F is either available A or reserved R. Both voice and data communication sources contend for the available slots according to the voice and data transmission probabilities that are set during the system design. If a voice communication source succeeds during the contention phase, an available slot is assigned to that communication source and is labeled as reserved. The reserved slot is thus made available to that communication source in subsequent frames during the time it is actively generating and transmitting voice packets. When the voice communication source has no more voice packets to transmit, it looses its reservation and goes back to the contention phase when it has additional voice packets to transmit. For the case of pure data communications, if a data communication source succeeds during the contention phase, it uses the available slot to transmit the data packet. However, this slot is not reserved in subsequent frames and remains available to be contended for in the immediately following frames.
[0007] Like PRMA, R-MA allows multiplexing to be performed at the talkspurt level and a voice communication source keeps a slot for as long as it is active while a data communication source must contend for a slot during each frame. However, in contrast to PRMA, R-MA requires that some amount of bandwidth be kept available for use in servicing connection requests. This bandwidth is provided in the form of dedicated contention slots C that are further divided into a plurality of mini-slots MS. Thus, in R-MA, it is on the mini-slot boundaries that connection requests are made in accordance with permission probabilities.
[0008] In DRMA, similar to PRMA and unlike R-MA, each available slot can be used for information transmission or for channel reservation and no slots are dedicated for servicing connection requests. Furthermore, similar to R-MA and unlike PRMA, when serving as a contention slot, a slot is divided into a plurality of mini-slots on whose boundary connection requests are made in accordance with permission probabilities. Again, once a slot is reserved for a voice communication source, it can be used by that voice communication source in subsequent frames for as long as there are voice packets to transmit. Data communication sources are assigned slots in only one frame for data packet transmissions.
[0009] Finally, in D-TDMA frames are further divided into contention slots, voice slots, and data slots. Voice communication sources are allocated slots from the voice slots and data communication sources are allocated slots from the data slots. A registered voice communication source is assigned a voice slot that is maintained until no further voice packets are transmitted. Data communication sources are again assigned slots in only one frame. Furthermore, like R-MA and DRMA, connection requests are made on mini-slot boundaries.
[0010] While these discussed schemes do provide respectable quality for voice and data communications, they nevertheless tend to fall short when evaluated for real-time video communications. For example, the described protocols fail to provide any mechanism for guaranteeing sustained bandwidth, bounded delay, and, accordingly, quality of service guarantees for video communications. Quality of service is an essential ingredient for the success of many real-time video applications and without it, under heavy loads, video tends to exhibit poor and sometimes intolerable quality.
[0011] A further disadvantage resides in the fact that the frame length in the described schemes is typically designed to be equal to the packet generation period of the voice encoder. In this manner, since one voice packet will be generated in one frame time, both delay and buffering are bounded for voice transmissions. For video transmissions, this choice of frame length has no meaning since video encoders typically generate packets at rates generally faster than voice encoders do. Accordingly, the one slot per frame guarantee does not function to prevent excessive delays or overflow buffering for video transmissions again resulting in video quality degradation.
[0012] Yet another disadvantage resides in the fact that these schemes typically omit video communication sources as a separately identifiable communication source when assigning slots on a priority basis. Accordingly, when video packets are treated as voice packets, the typically higher priority given to voice packets coupled with the high demand for bandwidth required by video transmissions tends to overwhelm the resources of the communication network while degrading all on-going connections. Similarly, when video packets are treated as data packets, the data packet requirement of contending for every slot tends to result in frequent collisions causing excessive delays in video transmissions that again function to lower both the quality of on-going connections and the overall bandwidth utilization of the communication network.
[0013] Finally, the described schemes that rely completely on contention to determine slot allocation will perform poorly under heavy load. Accordingly, when video communications are introduced into the communication network, the amount of data in the system is increased to the point where collisions are bound to escalate. This results in excessive delays and packet dropping for on-going video connections. This occurs even in those schemes that reserve a fixed amount of resources for contention purposes such as R-MA and D-TDMA.
[0014] From the foregoing, it is seen that a need exists for an improved channel access protocol. In particular, such a protocol is needed for use in establishing a full service network that provides comprehensive support for integrated transport of voice, video and data communications.
SUMMARY OF THE INVENTION
[0015] According to this need, the present invention is generally directed to a method for allocating between multiple communication sources a communication channel in a communication network. The method is performed by dividing the communication channel into a plurality of frames, dividing each of the frames into a plurality of slots, and dividing some of the plurality of slots into a plurality of first mini-slots. The mini-slots are provided for use by the multiple communication sources to request the establishment of a new voice, data, or video transmission connection over the communication channel. Additionally, one of the plurality of slots is divided into a plurality of second mini-slots for use by the multiple communication sources to request the establishment of a new voice, data, or video transmission connection over the communication channel and for use by the multiple communication sources to augment an existing video connection over the communication channel. In this manner a dynamic Time Division Multiple Access protocol frame is created that is available to support the integrated transport of voice, video and data communications over the communications network.
[0016] The subject invention is also described in P. Bahl, “ARMAP—An Energy Conserving Protocol for Wireless Multimedia Communications,” IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Boston, Mass., (Sep. 8-11, 1998) which is incorporated herein by reference in its entirety.
[0017] A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawings which set forth an illustrative embodiment which is indicative of the various ways in which the principles of the invention may be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] For a better understanding of the invention, reference may be had to a preferred embodiment shown in the accompanying drawings in which:
[0019] [0019]FIG. 1 illustrates the frame structure of selected prior art TDMA schemes;
[0020] [0020]FIG. 2 is a block diagram of the components that are used in connection with the subject invention;
[0021] [0021]FIG. 3 illustrates the architecture of a cellular communication network in which the components depicted in FIG. 2 may reside;
[0022] [0022]FIG. 4 is a further block diagram of the communication source, communication receiver, and network router depicted in FIG. 2;
[0023] [0023]FIG. 5 illustrates the frame structure of the ARMAP scheme that is used in accordance with the subject invention to transmit information between the components depicted in FIGS. 2 and 4;
[0024] [0024]FIG. 6A is a flow chart diagram generally depicting a method for generating the ARMAP frame structure illustrated in FIG. 5;
[0025] [0025]FIG. 6B is a flow chart diagram generally depicting a method for monitoring ARMAP NRS slots in accordance with the method illustrated in FIG. 6A;
[0026] [0026]FIG. 6C is a flow chart diagram generally depicting a method for monitoring ARMAP HRS slots in accordance with the method illustrated in FIG. 6A;
[0027] [0027]FIG. 6D is a flow chart diagram generally depicting a method for updating mini-slot allocations in accordance with the method illustrated in FIG. 6A; and
[0028] [0028]FIG. 6E is a flow chart diagram generally depicting a method for updating the ARMAP HRS slot generation frequency in accordance with the method illustrated in FIG. 6A.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Turning to the drawings, wherein like reference numerals refer to like elements, the invention is illustrated as being implemented in a suitable network environment. Although not required, the invention will be described in the general context of computer-executable instructions, such as program modules, being executed by a processing device such as a personal computer, mainframe computer, or the like. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the invention may be practiced with other processing devices such as consumer electronic devices having one or more processors such as, for example, mobile telephones. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communication network and where program modules are located in both local and remote memory storage devices.
[0030] With reference to FIG. 2, an exemplary network system in which the invention may reside is illustrated. The network system includes a communication source 20 illustrated in the exemplary form of a personal computer. The communication source 20 includes a processing unit 21 , a system memory 22 , and a system bus 23 . The system bus 23 functions to couple the various system components including the system memory 22 to the processing unit 21 . The system bus 23 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory 22 includes read only memory (ROM) 24 and random access memory (RAM) 25 . A basic input/output system (BIOS) 26 , containing the basic routines that help to transfer information between elements within the communication source 20 , such as during start-up, is stored in ROM 24 . The communication source 20 may also include a hard disk drive 27 , a magnetic disk drive 28 , or an optical disk drive 30 . It will be appreciated that these devices respectively allow for reading from and writing to a hard disk, reading from or writing to a removable magnetic disk 29 and for reading from or writing to a removable optical disk 31 , such as a CD ROM or other optical media.
[0031] When incorporated into the communication source 20 , the hard disk drive 27 , magnetic disk drive 28 , and optical disk drive 30 are connected to the system bus 23 by a hard disk drive interface 32 , a magnetic disk drive interface 33 , and an optical disk drive interface 34 , respectively. The drives and their associated computer-readable media provide nonvolatile storage of computer readable instructions, data structures, program modules and other data for the communication source 20 . It will be appreciated by those skilled in the art that other types of computer readable media that can store data may also be used. Examples of such media devices include, but are not limited to, magnetic cassettes, flash memory cards, digital videodisks, Bernoulli cartridges, random access memories, and read only memories.
[0032] A number of program modules may be stored in one or more of the memory devices and typically include an operating system 35 , one or more applications programs 36 , other program modules 37 , and program data 38 . A user may enter commands and information into the communication source 20 through input devices such as a keyboard 40 and pointing device 42 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 21 through a serial port interface 46 that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port or a universal serial bus (USB). A monitor 47 or other type of display device is also connected to the system bus 23 via an interface, such as a video adapter 48 . In addition to the monitor 47 , the communication source 20 may also include other peripheral output devices, not shown, such as speakers and printers.
[0033] The communication source 20 operates in a networked environment using logical connections to one or more remote communication receivers 49 , also illustrated in the exemplary form of a personal computer. The connection is typically made through a further processing device 100 that is responsible for network routing. In the illustrated embodiment, the remote communication receiver 49 will include many or all of the elements described above relative to the communication source 20 including the memory storage devices and monitor 47 . Furthermore, within such a networked environment, it will be appreciated that program modules depicted relative to the communication source 20 , or portions thereof, may be stored in the memory storage devices of the remote communication receiver 49 .
[0034] The description that follows will refer to acts and symbolic representations of operations that are performed by the processing devices 20 , 49 , 100 unless indicated otherwise. As such, it will be understood that such acts and operations, which are at times referred to as being computer-executed, include the manipulation by the CPUs of the devices of electrical signals representing data in a structured form. This manipulation transforms the data or maintains it at locations in the memory system, which reconfigures or otherwise alters the operation of the processing devices 20 , 49 , 100 in a manner well understood by those of skill in the art of computer systems. The data structures where data is maintained are physical locations of the memory that have particular properties defined by the format of the data. While the invention is being described in the foregoing context, it is not meant to be limiting as those skilled in the art will further appreciate that various of the acts and operation described herein may also be implemented in hardware.
[0035] In a preferred embodiment, the network environment comprises a wireless, cellular communication network such as depicted in FIG. 3. Nevertheless, while the invention will be described hereinafter in that context, those of skill in the art will appreciate how to adapt the features of the subject invention for us in other communication networks such as a local area network (LAN) or a wide area network (WAN). Accordingly, the description that follows is not intended to be limiting.
[0036] Turning to FIG. 3, a cellular communication network having architecture that is similar to the architecture that is found in a Global System for Mobility (GSM) network is illustrated. As will be well understood by those of skill in the art, mobile terminals MT communicate over a radio channel with a network router in the form of a base transceiver station BTS that is located within the same cell. The base transceiver stations BTSs of neighboring cells communicate over fiber-based channels with a base station controller BSC that serves as their manager. In turn, the base station controllers BSCs in a geographic region communicate over fiber-based channels with a mobile switching center MSC that serves as their manager. The mobile switching centers MSCs are connected to a public network that may include public switched telephone networks PSTNs, integrated services device networks ISDNs, or asychronous transport mode ATM networks.
[0037] More specifically, the mobile terminals MT within the network are envisioned to be communication sources 20 of the following types: 1) communication sources 20 VO performing voice packet transmissions; 2) communication sources 20 DA performing data packet transmissions; and 3) communication sources 20 VI performing video packet transmission. Meanwhile, linked to the public network as a destination for the transmissions originating from the mobile terminals MT are remote communication receivers 49 of the following type: 1) remote communication receivers 49 VO receiving voice transmissions; 2) remote communication receivers 49 DA receiving data transmissions; and 3) remote communication receivers 49 VI receiving video transmissions. The communication sources 20 VO and 20 DA may include voice and data encoders, respectively, of conventional design. However, it is preferred that the communication sources 20 VI include a video encoder in the form described in commonly owned, co-pending U.S. patent application Ser. No. 09/169,724 that is incorporated herein by reference in its entirety. It is also preferred that the remote communication receivers 49 VI be adapted to reconstruct the video information transmitted by the communication sources 20 VI in the manner described in said incorporated application.
[0038] In accordance with one important aspect of the invention, the communication network provides for the efficient transmission of video communications from the communication sources 20 VI to one or more associated remote communication receivers 49 VI for subsequent display to remote users. For this purpose, as illustrated in FIG. 4, the communication sources 20 VI are each provided with a video camera 152 that functions to capture video images as a series of digital video frames. Within the communication sources 20 VI, the video camera 152 is connected to a video encoder 154 via the system bus 23 . The video encoder 154 functions to generate information that is representative of the video frame which information is subsequently supplied to a transmitter 155 for broadcasting over the communication channel to the network router 100 , e.g., base station BS. Meanwhile, the remote communication receivers 49 VI each include a video decoder 156 that functions to recreate the video frame from the information received over the communication network. The decoded video frame may then be forwarded to an associated monitor 47 for viewing through the use of an appropriate video adapter 157 .
[0039] To facilitate the transmission of the information representative of the video frame over the communication channel, the system employs a derivative of the TDMA scheme given the moniker Adaptive Reservation Multiple Access (ARMAP). In ARMAP, the frame structure of which is illustrated in FIG. 5, the communication channel is divided into frames 158 of a given frame time duration and each frame is divided into slots 160 of a given slot time duration. Preferably, the frame time duration is set to be equal to an integer multiple of the voice encoder packet generation period for the voice encoder used within the communication sources 20 VO. In this manner, for the case of this integer multiple being one, the arrival of the slot within each frame that has been assigned to a communication source 20 VO is synchronized with the voice packet generation period of its voice encoder. This allows exactly one voice packet to be transmitted within each frame 158 for each voice connection. The size of the slots and, accordingly, the number of slots within the frame are preferably arrived at using the available system bandwidth, the voice encoder and the methodology described in the previously incorporated U.S. patent application Ser. No. 09/169,724. Accordingly, it will not be described in greater detail herein.
[0040] Within ARMAP, the slots 160 within each frame are further categorized as being either reserved slots 160 A or reservation slots 160 B. Reserved slots 160 A are slots that have been assigned to a communication source 20 for use in performing on-going voice or video transmissions over the communication network. Reservation slots 160 B are slots in which the network router 100 receives connection request messages issued by a communication source 20 that an unreserved or available slot be assigned to the communication source 20 for use in transmitting voice, data, or video information over the communication network. Preferably, all available slots are used as reservation slots 160 B.
[0041] The reservation slots 160 B within ARMAP are further categorized as being either normal reservation slots NRS or hybrid reservation slots HRS. If no on-going video connections are established within the communication network, all of the reservation slots 160 B will be of the normal reservation slot NRS variety. Both normal reservation slots NRS and hybrid reservation slots HRS are further divided into a plurality of mini-slots 162 having a mini-slot time duration. The mini-slots 162 are utilized by the communication sources 20 to contend for the resources of the communication channel. The mini-slot time duration is preferably established as a function of the number of bits that comprise the various request messages, the slot size and number of connections to be supported by the communication system.
[0042] All of the mini-slots 162 within the normal reservation slots NRS are contended for in an uncontrolled manner by the communication sources 20 . Meanwhile, only designated mini-slots 162 within the hybrid reservation slots HRS are contended for in an uncontrolled manner by the communication sources 20 . Specifically, the mini-slots 162 within the hybrid reservation slots HRS are further partitioned whereby some of the mini-slots 162 V are contended for in a controlled manner while the remaining mini-slots 162 N are contended for in the usual uncontrolled manner. The reason for this further partitioning within the hybrid reservation slot will be made apparent from the description that follows.
[0043] The network router 100 will accept within the mini-slots 162 of the normal reservation slots NRS a connection request message issued by a communication source 20 for the purpose of establishing a new voice, data or video connection. Additionally accepted by the network router 100 within the mini-slots 162 of the normal reservation slots NRS are reservation request messages issued by communication sources 20 VO and 20 DA for the purpose of supporting an on-going voice or data connection, respectively. The network router 100 will not accept within the mini-slots 162 of the reservation slots NRS a reservation request message issued by a communication source 20 VI for the purpose of supporting an on-going video connection.
[0044] The network router 100 will accept within the mini-slots 162 N of the hybrid reservation slots HRS a connection request message issued by a communication source 20 for the purpose of establishing a new voice, data or video connection. Additionally accepted by the network router 100 within the mini-slots 162 N of the hybrid reservation slots HRS are reservation request messages issued by communication sources 20 VO and 20 DA for the purpose of supporting an on-going voice or data connection, respectively. The network router 100 will not accept within the mini-slots 162 N of the hybrid reservation slots HRS a reservation request message issued by a communication source 20 VI for the purpose of supporting an on-going video connection. Such reservation request messages are, however, accepted by the network router 100 within the mini-slots 162 V of the hybrid reservation slots HRS to the exclusion of any other type of request message.
[0045] The network router 100 is responsible for notifying the contending communication sources 20 of the success or failure of their connection request. It is preferred that real-time voice communication connection request messages be afforded the highest priority while non-real time data voice communication connection request messages bear the lowest priority. If a communication source 20 is successful during the contention phase, the network router 100 will initiate a dialog with the communication source 20 and execute the steps necessary to create the connection. As will be appreciated by those of skill in the art, these steps typically include providing the communication source 20 with a connection identifier that is used by the communication source 20 for the purpose of identifying the source and destination addresses for all subsequent packet transmissions. Once this connection has been established, the communication sources 20 are then required to issue reservation request messages before transmissions may commence. Upon the receipt of a reservation request message, the network router 100 will assign slots 160 to the requesting communication source 20 as a function of the type of communications to be issued by the communication source 20 .
[0046] Slots are assigned to the communication sources 20 either statically or dynamically. Under normal operation, static assignments are maintained for the lifetime of the connection while dynamic assignments are varied, typically as a function of the nature of the reservation request and available bandwidth. Reservations for statically assigned slots are made concurrently with connection establishment requests wherein the connection request message includes a bit pattern signifying to the network router 100 the exact number of slots 160 that the connecting communication source 20 wishes to be assigned. Reservations for dynamically assigned slots are made in reservation requests wherein the reservation request message includes a bit pattern signifying to the network router 100 the exact number of slots 160 that the communication source 20 wishes to be assigned. Successfully reserved slots may be canceled by explicit or implicit disconnect messages. Implicit disconnection is assumed if the connected communication source 20 fails to use the reserved slot 160 A it has been assigned for a predetermined period of time, typically one frame. The issuance of an end-of-transmission (EOT) sequence by the connected communication source 20 makes explicit disconnection. In the preferred embodiment, only video connections are allowed to make static reservations. Video connections are also allowed to make dynamic reservations. Data and voice connections are limited to dynamic reservations.
[0047] For non-real time data transmissions, a success during the dynamic reservation phase insures that the network router 100 will shortly reserve a slot 160 for use by the communication source 20 DA. The communication source 20 DA must listen to messages from the network router 100 to determine which slot 160 is being made available as a reserved slot 160 A for its use. When the slot 160 A becomes available for use by the communication source 20 DA, the communication source 20 DA transmits its data packet within the slot 160 A. For data connections, the single slot 160 A is reserved for only one frame. Accordingly, once the frame has expired, the network router 100 makes the slot available to all communication sources 20 on the communication network in the form of a reservation slot 160 B. To make any further data transmissions, the communication source 20 DA must again contend for the communication channel through the issuance of another reservation request message.
[0048] For real-time voice transmission, a success during the dynamic reservation phase insures that the network router 100 will provide one slot 160 in successive frames 158 for use by the communication source 20 VO in which the communication source 20 VO may transmit its voice packets. Delay restrictions associated with voice packet transmissions further ensure that the network router 100 will only indicate a successful request if it is able to provide a slot 160 no later than one frame measured from the frame in which the request was made. The communication source 20 VO must listen to messages from the network router 100 to determine which slot 160 is being made available as a reserved slot 160 A for its use. The network router transmits these messages at the start of every time frame in the form of beacon signals. When the slot 160 A becomes available for use by the communication source 20 VO, the communication source 20 VO transmits its voice packet within the slot 160 A as it arrives within each frame 158 . This reservation is canceled upon the receipt of an EOT by the network router 100 or if the network router 100 fails to receive a voice packet from the communication source 20 VO during the reserved slot 160 A. Upon cancellation of the slot reservation, the network router 100 makes the slot available to all communication sources 20 in the communication network in the form of a reservation slot 160 B. To make any further voice transmissions, the communication source 20 VO must again contend for the communication channel through the issuance of another reservation request message.
[0049] For real-time video connections, dynamic reservations are more complex but are made without contention. As was described previously, video reservation requests made by a communication source 20 VI will only be accepted by the network router 100 during the hybrid reservation slots HRS. Furthermore, for the purpose of avoiding contention, video reservation requests made by the communication source 20 VI will only be accepted by the network router 100 during the mini-slot 162 V within the hybrid reservation slot HRS that the communication source 20 VI has been assigned. The network router 100 makes this acceptance of the video reservation request message to the exclusion of all other types of requests. Specifically, contention is avoided since each communication source 20 VI is assigned its own mini-slot 162 V. Mini-slots 162 N that have not been assigned to a communication source 20 VI are open to be contended for by voice reservation requests, data reservation requests, and all connection requests. The network router 100 uses the down link channel to broadcast to the communication sources 20 , preferably at the start of each frame, the reservation slots that the network router 100 has categorized as hybrid reservation slots HRS. Additionally, the network router 100 uses the down link channel to broadcast the position of the mini-slot 162 V within each hybrid reservation slot HRS that has been assigned to each of the communication sources 20 VI.
[0050] To determine the frequency with which hybrid reservation slots HRS are to be created within the frames, the network router 100 preferably monitors the number of reservation requests issued by the communication sources 20 VI which are indicative of their video compression cycles. The video compression cycle is defined as the capture, compression and packetization of a single image-frame within the video sequence. Packetization includes fragmenting the compressed image-frame into fixed size packets, adding the appropriate header bits, and adding error correcting codes to each packet. The reason that the rate at which a communication source 20 VI makes a reservation request is indicative of its video compression cycle results from the fact that reservation requests are typically issued at the end of each video compression cycle. The correlation between the rate of reservation requests and video compression cycles is further enhanced by the fact that there exists an underlying regularity in which video packets are generated for transmission. This regularity is set by the frame capture and compression rate of the video encoder.
[0051] In practice, however, due to bandwidth limitations, encoder complexity, and power limitations, the actual video packet generation rate will vary between the different communication sources 20 VI. For this reason, each communication source 20 VI is preferably monitored individually. A difference in the video compression cycles of the communication sources 20 VI may also arise from the fact that some of the communication sources 20 VI will include hardware that performs video compression while others rely only on software. Additionally, differences in the processing power of CPUs within the communication sources 20 will also tend to cause the video compression cycles to vary. Finally, differences in the content of the video to be transmitted will affect the speed of the video compression cycles.
[0052] The information the network router 100 gathers regarding the video compression cycles of each of the communication sources 20 VI may be used to dynamically control the frequency that hybrid reservation slots HRS appear within each frame 158 . Additionally, this information may also used to dynamically control the frequency that mini-slots 162 V are assigned to the communication sources 20 VI within the hybrid reservation slots HRS. In this manner, the network router 100 tailors the communication channel to the requirements of the communication sources 20 VI such that timely and optimum usage of the radio resource is achieved.
[0053] The adaptive reservation slot generation algorithm utilized within the subject invention is now more specifically described. As illustrated in FIGS. 6 A- 6 E, the network router 100 monitors the normal reservation slots NRS for the purpose of determining if a request message has been issued by one of the communication sources 20 . If, as illustrated in FIG. 6B, a communication source 20 has issued a connection request message, the network router 100 evaluates the connection request message to determine the type of transmission connection the communication source 20 wishes to establish. If the connection request is for a video connection, the network router 100 determines if the connection will be allowed and accordingly notifies the requesting communication source 20 .
[0054] Within the network router 100 , the number of communication sources 20 VI having video connections is tracked. Additionally, for each of these communication sources 20 VI, the number of mini-slots 162 V that have been assigned to the corresponding communication source 20 VI and their usage is also tracked. Accordingly, when the network router 100 has accepted a new video connection, the network router 100 updates its video connection counter and initializes the corresponding mini-slot 162 V usage counter.
[0055] Upon the acceptance of a new video connection, the base station also checks to determine if this is the first video connection established within the communication network. If the connection is the first video connection, the network router 100 sets the hybrid reservation slot HRS frequency to its maximum value. This maximum value is preferably pre-established within the network router 100 to be equal to the video packet generation rate of the fastest video encoder that could find its way into the communication network. The network router 100 may, however, dynamically vary this maximum value, for example, as a function of channel traffic. Then, for each new video connection, the network router 100 sets the corresponding mini-slot 162 V allocation counter to be equal to the hybrid reservation slot HRS frequency. In this manner, each new video connection is initially allocated one mini-slot 162 V within each hybrid reservation slot HRS, i.e. its mini-slot allocation frequency is equal to the hybrid reservation slot HRS frequency.
[0056] Once a video connection has been established within the network, the network router 100 will periodically use, as illustrated in FIG. 6A, the next reservation slot 160 B that comes available as a hybrid reservation slot HRS according to the hybrid reservation HRS slot frequency. The network router 100 then monitors this hybrid reservation slot HRS for requests as illustrated in FIG. 6C. When monitoring the hybrid reservation slot HRS, the network router 100 first initializes an internal counter to one and checks the first mini-slot 162 V to see if the communication source 20 VI that has been assigned this reservation slot 162 V has made a reservation request. If a reservation request message has been issued, the corresponding mini-slot usage counter is incremented by one and the request is processed. If no reservation request message has been issued, the internal counter is incremented and then checked against the video connection counter to determine if the previously described process should be repeated. If there are no further mini-slots 162 V to examine, i.e., the internal counter is greater than the number of video connections, the network router 100 checks the remaining mini-slots 162 N, if any exist, for request messages and performs and required actions.
[0057] Once the hybrid reservation slot HRS has been monitored by the network router 100 , the reservation slots 160 B continue to be utilized by the network router 100 as normal reservation slots NRS that are appropriately monitored, as illustrated in FIGS. 6A and 6B. This continues until the network router 100 once again determines that it is time to use the next reservation slot 160 B that comes available as a hybrid reservation slot HRS. This determination is again made as a function of the hybrid reservation slot HRS generation frequency. However, before the next available reservation slot 160 B is used as a hybrid reservation slot HRS, the base station preferably performs a threshold time check for purposes of determining if any further updates of its internal counters or the hybrid reservation slot HRS generation frequency are needed. This threshold time is preferably set to be equal to approximately one second.
[0058] If the threshold time has expired, the network router 100 evaluates its internal counters as illustrated in FIG. 6D for the purpose of updating the hybrid reservation slot HRS frequency or the mini-slot 162 V allocation frequency. This updating is performed in order to match mini-slot allocations to the video compression cycle rate of the communication sources 20 VI. Specifically, for each video connection, the network router 100 checks the mini-slot 162 V usage counter against the mini-slot 162 V allocation counter. If all of the allocated mini-slots 162 V were used, the mini-slot 162 V allocation counter is incremented by one provided that the mini-slot 162 V allocation counter does not exceed the maximum value set for the hybrid reservation slot HRS frequency. If not all of the allocated mini-slots 162 were used, the mini-slot 162 V allocation counter may optionally be decremented by one (provided that the mini-slot 162 V allocation counter does not go below a minimum value, typically set to one), be set equal to the mini-slot usage counter, or not altered at all. Thereafter, the mini-slot 162 V usage counter is reinitialized to zero.
[0059] Once the mini-slot 162 allocation counter for each of the on-going video connections has been updated, the network router 100 updates the hybrid reservation slot HRS frequency as illustrated in FIGS. 6A and 6E. Specifically, for each on-going video connection, the network router 100 compares the mini-slot 162 V allocation counter against the current hybrid reservation slot HRS frequency and, if the value is greater, the hybrid reservation slot HRS frequency is set equal to the mini-slot 162 V allocation counter value. If no on-going video connections exist, the hybrid reservation slot HRS frequency is once again set to zero. Any changes that may result from this threshold updating will be issued to the communication sources 20 VI by the network router 100 on the down link channel.
[0060] It will be appreciated that after these adjustments have been made an on-going video connection may no longer be allocated a mini-slot 162 V within each hybrid reservation slot HRS. This occurs when a communication source 20 VI has a video compression cycle rates that is lower than the hybrid reservation slot HRS frequency. This tuning of the hybrid reservation slot HRS frequency and mini-slot 162 V allocation does, however, result in optimal allocation of the reservation slots 160 B and the best usage of radio resources for all communication sources 20 .
[0061] In a further embodiment of the invention, the above-described algorithm may be modified to check for allocation oscillations that tend to result in bandwidth wastage. Allocation oscillations can be detected by tracking the pattern of the adjustments performed on the mini-slot 162 V allocation counters for each video connection. For example, a pattern of alternating zeros and ones may signify that oscillation is occurring. In such a case, it is assumed that the communication source 20 VI has reached an equilibrium capture and compression cycle rate and, as such, the mini-slot allocation algorithm can be modified to prevent any mini-slot 162 V allocation counter adjustments for a predetermined period of time.
[0062] It is further contemplated that communication sources 20 VI that are capable of transmitting video at rates faster than what the channel can handle can conserve power by monitoring the number of mini-slots 162 V that they have been allocated and adjusting their video compression cycle rate accordingly. By way of example, a communication source 20 VI may be capable of transmitting at a rate of 20 video frames per second while only being allocated 10 mini-slots per second due to heavy traffic. In such a case, by monitoring the number of reservations it was able to make, this communication source 20 VI can adapt to the available radio resources by reducing its capture and compression rate to 10 frames per second. In this manner, power wastage is avoided and the spatial quality of the video image may be preserved.
[0063] As described previously, at the end of each video compression cycle the video packets generated by the communication sources 20 VI are placed in a queue for subsequent transmission over the communication network. A portion of these packets will be dispatched within slots 160 A that have been statically assigned to the communication sources 20 VI during connection establishment time. The remaining packets are dispatched in slots that are dynamically assigned to the communication sources 20 VI as a result of reservation requests. When making dynamic reservation requests, the communication sources 20 VI specify within the request issued during the mini-slot 162 V they have been allocated the exact number of packets they have in their transmission queue that are desired to be transmitted. If the network router 100 is able to accommodate the reservation request, or part of the request, it acknowledges the request and provides the communication source 20 VI with the number and location of slots within which the packets may be transmitted.
[0064] The time duration of the mini-slots 162 is of sufficient length to accept the reservation request. Nevertheless, the number of bits that can be transmitted within the mini-slot 162 will have an impact upon the maximum number of slots that can be requested in a reservation request message. This impact can be minimized using an approach centered on the use of a quantization table. In particular, since the coding scheme and the type of video being transmitted will generally be known to the communication sources 20 VI, the communication sources 20 VI can approximate the number of packets that will be generated as a result of their compression cycle. Additionally, the communication sources 20 VI will know the fixed number of bits that are available for use in requesting bandwidth. Using this information, the communication sources 20 VI can establish a quantization table in which various bit patterns are optimally mapped to reservation requests for different numbers of slots, preferably utilizing a Lloyd-Max quantizer. When a connection is established, each communication source 20 VI will communicate their computed quantization table to the network router 100 , which the network router 100 maintains as state information for the duration of the connection. In this manner, during a reservation request, the communication source 20 VI transmits the quantization level to the network router 100 as a chosen bit pattern which the base station indexes against the quantization table to determine how many slots the communication source 20 VI is requesting to be reserved. Thus, the limitation on the number of slots that can requested by the communication source in a single reservation request using a fixed number of bits can be overcome.
[0065] In view of the many possible embodiments to which the principles of this invention may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures is meant to be illustrative only and should not be taken as limiting the scope of invention. For example, those of skill in the art will recognize that the elements of the illustrated embodiments shown in software may be implemented in hardware and vice versa or that the illustrated embodiments can be modified in arrangement and detail without departing from the spirit of the invention. Therefore, the invention as described herein contemplates all such embodiments as may come within the scope of the following claims and equivalents thereof.
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A full service channel access protocol that supports the integrated transport of voice, video and data communications is provided by dividing a communication channel into a plurality of frames, dividing each of the frames into a plurality of slots, and dividing some of the plurality of slots into a plurality of mini-slots. The mini-slots are provided for use by the multiple communication sources to request the establishment of a new voice, data, or video transmission connection over the communication channel. Additionally, a second one of the plurality of slots is divided into a plurality of second mini-slots for use by the multiple communication sources to request the establishment of a new voice, data, or video transmission connection over the communication channel and for use by the multiple communication sources to augment an existing video connection over the communication channel. The method enables timely and power efficient communications over communication network
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent Application No. 102007038971.1, filed Aug. 17, 2007, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The invention relates to a machine element for a shaft-hub connection for the torque-proof coupling of rotating or fixed machine elements with shafts by means of a lever actuated eccentric clamping sleeve, as well as a corresponding manufacturing method.
BACKGROUND
[0003] Various devices have in the past been suggested for establishing torque-proof connections between rotating or fixed machine elements, such as shafts that continuously rotate or alternatively rotate to and fro, and machine elements immovably secured thereto, such as levers, pulleys, cams, toothed wheels and the like. For example, DE 43 27 461 A1 discloses a device for the torque-proof connection of a shaft with a hexahedrally bordered machine part by means of a lever-actuated eccentric clamping sleeve. The latter includes a slit sleeve with an outer wedge profile, and the sleeve can be rotates against the outer machine element, thereby becoming jammed between the shaft and outer machine element.
[0004] The lengthwise slit introduced in the sleeve enables an elastic deformation of the sleeve in a radial direction. However, the truth of running is limited. Further, clamping can give rise to stresses that are so high that the machine element with the hub can be damaged, in particular at small shaft diameters.
[0005] In view of the foregoing, at least one object is to create a machine element that enables an easy to manufacture and convenient to use shaft-hub connection, and can absorb high levels of force, as well as to provide a method for manufacturing such a shaft-hub connection. In addition, other objects, desirable features, and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
SUMMARY
[0006] The at least one object, other objects, desirable features, and characteristics, is achieved by means of a machine element for a shaft-hub connection that includes, but is not limited to a receiving area and a clamping element without a slit incorporated in the receiving area that has an opening for accommodating a shaft and can be twisted against the machine element. The machine element also includes, but is not limited to a support sleeve arranged radially outside relative to the clamping element.
[0007] The at least one object, other objects, desirable features, and characteristics are also achieved by a manufacturing method. The method including, but not limited to the steps of preparing a machine element for a shaft-hub connection that includes, but is not limited to a receiving area and a clamping element without a slit incorporated in the receiving area that has an opening for accommodating a shaft and can be twisted against the machine element. The machine element also includes, but is not limited to a support sleeve arranged radially outside relative to the clamping element. The method further includes, but is not limited to machining the clamping element, in particular by drilling, turning and/or grinding, to generate the opening, insertion of a shaft into the opening and twisting the shaft and/or clamping element relative to the machine element to establish a torque-proof connection between the shaft and machine element.
[0008] The machine element for a shaft-hub is used for the torque-proof coupling of rotating machine elements with shafts, and the rotating machine elements include toothed wheels, pulleys, axial locking rings, parts of bearing arrangements, parts of sealing arrangements, levers and the like. The rotating motion of the respective machine element can be a continuous rotating motion with constant or alternating speed, with constant rotating direction or also a back-and-forth rotating motion with alternating rotating direction. The shaft can be a solid shaft, a hollow shaft or the like. Its exterior has a bearing surface that is preferably cylindrical.
[0009] The machine element has a receiving area, which incorporates a clamping element without a slit. In other words, the clamping element has no radially continuous slit in the lengthwise direction, and hence is continuously closed in the peripheral direction. It can preferably be elastically compressed in the radial direction, made possible through the selection of an appropriately low wall thickness of the clamping element, for example. The elasticity of the clamping element can be increased even further by providing it with longitudinal grooves or inclined grooves inside and/or outside. However, the latter do not penetrate through the clamping element, i.e., no slits are formed. The clamping element exhibits an opening, in particular a central borehole for accommodating the shaft, and the diameter of the opening is such that the clamping element can be slipped onto the shaft with little clearance. The elasticity of the clamping element is great enough to overcome the existing clearance during the elastic deformation of the clamping element, so as to secure the clamping element on the shaft friction-tight. The clamping element is elastically deformed through the relative twisting of the clamping element against the machine element. According to an embodiment, the machine element has a support sleeve that is arranged radially outside relative to the clamping element, and can absorb compressive forces. In particular, the clamping element is arranged inside the support sleeve, preferably in a concentric manner. It is especially preferred that the support sleeve exhibit a length in an axial direction measuring at least the axial length of the clamping element.
[0010] The support sleeve can at least partially absorb the forces exerted on the machine element by the clamping element, so that stresses within the material of the machine element can be reduced. As a result, the machine element can also be used for shafts with relatively small diameters, making it possible to use tools with a smaller jaw spans during the assembly of the shaft-hub connection. In addition, a less expensive material can be used for the machine element, so that a machine element can be made out of plastic, in particular a duromer, without having to worry about component failure. In particular, the machine element exhibits a duroplastic material, which improves the service life and wears resistance.
[0011] The machine element is preferably fabricated via casting, in particular (plastic) injection molding. As a result, the support sleeve and/or clamping element can be sheathed by the machine element. This simplifies production, and yields a good connection with the material of the machine element.
[0012] In particular, the support sleeve has feed-through openings that in particular run in essentially a radial manner. This reduces the weight without significantly detracting from stability. In addition, the bond between the support sleeve and machine element can be improved. In particular if the support sleeve is sheathed by the machine element, the material of the machine element can penetrate into the feed-through openings and provide an additional positive fit, so that in particularly distinctly higher shearing forces can be conveyed.
[0013] In order to further improve the bond between the support sleeve and machine element, the contouring of the support sleeve can be coarsened. For this purpose, the support sleeve can have an average roughness R a of about 0.1-50 μm, in particular about 1.0-50 μm, preferably about 3.0-50 μm, and especially preferred about 10.0-50 μm. Additionally or alternatively, the support sleeve can have notches, and the notches can in particular be fabricated without cutting via cold forming, rolling, embossing, sand blasting or shot preening. In particular when sheathing with the material of the machine element, the irregular surface of the support sleeve makes it possible to achieve an additional positive fit, which enables the transfer of higher forces.
[0014] The thickness of the support sleeve can be adjusted depending on the application. For example, the thickness of an essentially annular cylindrical support sleeve can be increased so as to enable the absorption of higher compressive forces and stresses. It is particularly preferred that the support sleeve be thick enough to provide at least one threaded borehole running in an axial direction in the support sleeve. As a result, the machine element can be connected with another component via the support sleeve, without having to provide a direct connection with the material of the machine element. This makes it possible to use a material for the machine element that might not be particularly well suited for a connection with other components, for example, owing to its brittleness. The increased flexibility in material selection permits the use of less expensive materials.
[0015] The clamping element can basically be incorporated into the machine element in different ways. In a first embodiment, for example, it is pressed into the machine element, so as to be held there in a press fit. The corresponding cam profile can be rough-finished in the machine element. It is also possible to design the clamping element in such a way as to itself fabricate the cam profile in a cutting process. It is radially pre-compressed by the press fit. The desired truth of running for the machine element is now established by preferably machining the borehole of the clamping element. For example, it is turned out, drilled out, ground out, etc. In addition, one or both faces of the clamping element or machine element can be end faced if they project over the machine element. Turning, milling, grinding or similar machining processes are again possible.
[0016] The clamping element is most preferably incorporated into the machine element already during the manufacture of the latter. For example, the machine element consists of a material that can be injection or transfer molded, such as diecast zinc, aluminum, a thermoplastic, duroplastic, duromer or another plastic, either reinforced with fiber or not. During the manufacture of the machine element, the clamping element can be introduced in the corresponding mold, and sheathed by the material of the machine element. In this state, the clamping element preferably still exhibits a wall thickness that is greater than desired and required for later use. In this molding process, the material of the machine element sheaths the clamping element, thereby adjusting to its external shape. The machine element thereby forms a receiving area for the clamping element that automatically exhibits an internal contour that fits the external contour of the clamping element. In particular, the external shape of the clamping element has at least one, but preferably two or three cam surfaces, which can be viewed as wedging surfaces, bent in the peripheral direction, and have the same direction of inclination.
[0017] After molding the machine element, the clamping element is preferably centrally machined. This can be done by turning, drilling, grinding or another type of machining process. For example, the machine element is accommodated by the clamping system of a machining device (e.g., the chuck of a lathe), after which the central borehole is turned to size. This automatically produces the desired dimensional correlation between a reference surface of the machine element and the central receiving borehole. Also achieved is the desired thinness of the clamping element walls, and hence its radial elasticity. For example, if the machine element is a pulley, the latter can be held on its outer periphery or some other reference surface, so as to achieve the desired centering of the borehole of the clamping element.
[0018] One or more mold clamping profiles are preferably provided on the clamping element and at a suitable location of the machine element, so as to hold tools for applying a relative clamping moment. For example, these profiles include an outer hub profile and inner clamping element profile (e.g., a bihexagonal Allen wrench or a claw coupling profile on the face).
[0019] The embodiment further relates to a shaft-hub connection with which rotating machine elements can be coupled in a torque-proof manner to shafts. The shaft-hub connection exhibits a shaft with a bearing surface and a machine element, and the machine element can be designed and further developed as described above. The bearing surface of the shaft is connected with the machine element via the clamping element. The shaft-hub connection is easy to fabricate, effective in use, and permits the absorption of high forces.
[0020] The embodiment further relates to a method for manufacturing a shaft-hub connection that involves first providing a machine element that can be designed and further developed as described above. The clamping element is then machined, in particular through drilling, turning and/or grinding, to create the opening. Subsequently, a shaft is inserted into the opening. Finally, the shaft and/or clamping element are twisted relative to the machine element to achieve a torque-proof connection between the shaft and machine element.
[0021] In particular, the machine element and clamping element are snapped onto the shaft to fabricate the shaft-hub connection between the machine element and shaft. This takes place after correspondingly establishing the interior dimensions of the clamping element and exterior dimensions of the shaft with a low clearance, and can hence be easily accomplished by hand. Corresponding handling systems or lever apparatuses, such as wrenches, are now positioned on the machine element and clamping element and a relative rotation is executed. As a rule, there is a weak material connection between the clamping element and the material of the machine element, which can be overcome with a slight torque if the outer surface of the clamping element is correspondingly smooth. The clamping element is broken off in the process. Once this has occurred, turning the clamping element generates a radial force that secures the machine element and clamping element to the shaft friction-tight.
[0022] It has been shown that the shaft-hub connections manufactured in this way are indeed durable and capable of bearing. They have a high truth of running at the lowest manufacturing costs. The type of connection can be used in a variety of ways.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
[0024] FIG. 1 shows a vertical sectional view of a shaft-hub connection with the machine element according to an embodiment;
[0025] FIG. 2 shows a vertically cut view a hub of the machine element for attachment to a shaft prior to hollowing process;
[0026] FIG. 3 shows a front view of the hub according to FIG. 2 ;
[0027] FIG. 4 shows a front view of the clamping element of the hub according to FIG. 3 ;
[0028] FIG. 5 shows a side view of the clamping element according to FIG. 4 ;
[0029] FIG. 6 shows a lengthwise cut view of the clamping element according to FIG. 5 prior to hollowing process;
[0030] FIG. 7 shows a partial lengthwise cut view of a shaft with an axial locking ring with wedge clamping device according to an embodiment; and
[0031] FIG. 8 shows a cut along the VIII-VIII line of the shaft and axial locking ring according to FIG. 7 .
DETAILED DESCRIPTION
[0032] The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding summary and background or the following detailed description.
[0033] FIG. 1 shows a shaft-hub connection 1 between a machine element 2 in the form of a pulley 3 and a shaft 4 or a shaft end. The shaft 4 is used to drive an aggregate 5 in a motor vehicle (not shown in any greater detail). However, the shaft-hum connection can be used elsewhere for connecting other machine elements and shafts.
[0034] The shaft end 4 is essentially cylindrical. It has a face 6 that is preferably essentially flat, and sits inside an opening in the form of a borehole 7 of a clamping element 8 incorporated in a hub 9 of the pulley 3 . The clamping element 8 , and hence the borehole 7 , are concentrically oriented relative to a rotational axis 10 that coincides with the rotational axis of the shaft 4 .
[0035] The pulley 3 has a support sleeve 26 , which can be used to absorb forces and stresses arising in the pulley 3 , so that the pulley 3 can tolerate distinctly higher forces emanating from the clamping element than without a support sleeve 26 . The support sleeve 26 is arranged concentrically relative to the clamping element 8 , and radially outside relative to the clamping element 8 . In the exemplary embodiment shown, the support sleeve 26 and clamping element 8 have essentially the same axial length. The support sleeve 26 exhibits several feed-through openings 27 , so that the bond between the support sleeve 26 and pulley 3 can be improved in particular if the support sleeve 26 is sheathed by the pulley 3 . In this case, the material of the pulley 3 can flow into the feed-through openings 27 and penetrate through the support sleeve 26 . In the exemplary embodiment shown, the support sleeve further exhibits schematically depicted threaded boreholes 28 , so that further components (not shown) can be easily connected with the pulley 3 via the support sleeve 26 .
[0036] The pulley 3 is not limited in shape. It can be set up for narrow belts as shown in the top half of FIG. 1 , or for wide belts as shown in the bottom half of FIG. 1 . The outer portion of the pulley 3 is connected with the hub 9 via a narrow, disk-shaped section 11 . As shown, the outside of the hub 9 can be conical, or alternatively be cylindrical or some other shape (e.g., as a crown gear, toothed wheel, flat pulley, frictional wheel, cam or the like). In addition, the outer edge of the pulley 3 can have essentially cylindrical annular surfaces 12 , 13 , which are provided on either side of the disk-shaped sections 11 .
[0037] The pulley 3 can be formed of a plastic, for example a duroplastic material, a thermoplastic material, or a metal that is not too solid, such as diecast zinc, aluminum, an aluminum alloy, magnesium, a magnesium alloy or the like. The pulley 3 is preferably manufactured in an injection or transfer molding process. The latter, in particular, is preferably used when using fiber-reinforced plastics with a high content of fiber.
[0038] As evident from FIG. 2 along with FIG. 4 to 6 , the clamping element 8 is essentially sleeve-shaped in design. It has a relatively thin wall 14 , which centrally envelops the borehole 7 . For example, the wall 14 consists of a metal, such as steel. The clamping element 8 is slightly flexible in the radial direction. In this case, its wall 14 is closed over its entire periphery, i.e., no slits are provided. The elasticity is created by predetermined bending points or breaking points, or by the thinness of the clamping element wall.
[0039] The outside of the clamping element 8 has at least one, and preferably two, essentially cylindrical jacket surface sections 15 , 16 , between which a clamping section 17 is arranged. The clamping section 17 exhibits a profile that is not circular. One such example is illustrated on FIG. 4 . In the present case, it consists of two cylindrically bent cam surfaces 18 , 19 , the radii R of which relate to midpoints M 1 , M 2 , which each are spaced apart from the rotational axis 10 .
[0040] The cylindrical section of the borehole 7 is followed by an Allen wrench segment 20 bordered hexagonally or on multiple surfaces. The mold clamping profile can also be a front claw profile. The latter is used for placing an Allen wrench in order to twist the clamping element 8 against the machine element 2 .
[0041] The hub 9 is correspondingly provided with a mold clamping profile 21 , for example in the form of a toothed profile or notched profile, which is also suitable for the placement of a torque-generating tool, such as a clamping system or the like. The Allen wrench section 20 and mold clamping profile 21 are separately displayed on FIG. 3 . This figure illustrates the hub 9 and a portion of the disk-shaped section 11 enveloping it.
[0042] Based on the example of the pulley 3 , the machine element 2 is manufactured as follows: The pulley 3 is manufactured using an injection molding tool with a central receptacle for the clamping element 8 . The latter is already provided with its Allen wrench profile or other profile. It can also exhibit the completely machined borehole 7 . However, it most preferably has a greater wall thickness, (i.e., the borehole 7 is undersized). The clamping element 8 is positioned in the injection molding tool in such a way that the outer cylindrical surface sections 15 , 16 are arranged largely coaxial to the later desired rotational axis. The precision requirements are here not all that stringent. The hub 9 , section 11 and outer part of the pulley 3 are then fabricated in the injection molding process, wherein the here liquid or plastic material envelops the clamping element 8 . As a result, in particular the clamping section 17 projecting radially outward over the surface sections 15 , 16 are overlapped on both sides by the material of the hub 9 . The material of the hub 9 seamlessly abuts the preferably very smooth surface of the clamping element 8 . If necessary, a liquid or powder release agent can be applied to prevent too intimate a bond between the material of the hub 9 and the outer surface of the clamping element 8 .
[0043] After the pulley 3 has been molded, the borehole 7 is formed centrally relative to the rotational axis 10 , and the wall thickness of the clamping element 8 is reduced. For example, this can be accomplished by drilling or, as preferred, hollowing out. To this end, the pulley 3 is accommodated by a clamping system on a suitable surface, for example the annular surface 12 or 13 , or on its outer edge 22 . It is then concentrically turned relative to the rotational axis 10 , and the inner surface of the borehole 7 is machined to size with a hollowing tool. This size (i.e., the inner diameter established in this way) is large enough so that the pulley 3 with the borehole 7 can be easily slipped onto the shaft 4 by hand, without generating too great a resistance or too much clearance.
[0044] The clamping element 8 is twisted slightly against the hub 9 to manufacture the shaft-hub connection 1 . To this end, a clamping system or tool is placed in the Allen wrench section 20 , and a corresponding gripper is placed on the clamp molding profile 21 . Twisting the clamping element 8 against the hub 9 by several (few) degrees first loosens a potentially adhesive bond between the clamping element 8 and pulley (i.e., the clamping element 8 is broken off). This is followed on FIG. 4 by a clockwise rotation (i.e., in such a way that the cam surfaces of the counter-surfaces 23 , 24 formed in the hub 9 during the injection molding process are forced radially inward). As a result, the centering of the sleeve formed by the clamping element 8 is retained owing to the centering of the surface sections 15 , 16 . The clamping element 8 deforms elastically, wherein the inner wall of the borehole 7 presses rigidly against the shaft 4 , in particular in the area of the clamping section 17 , creating a torque-proof connection. This yields a precisely true running, easily manufactured shaft-hub connection that can be detached again if needed.
[0045] FIG. 7 depicts a modified application. The shaft-hub connection serves for axially securing a locking ring 23 , illustrated in the top half of FIG. 7 and bottom half of FIG. 7 in different variants. For example, it differs in terms of axial length. The face of the axial locking ring 23 can exhibit teeth 24 used to secure a tool. The locking ring 23 can consist of plastic, steel or another material. The clamping element 8 is once more pressed into a central opening of the machine element 2 here designed as the locking ring 23 , and can be rotated against the locking ring 23 , so as to elastically deform radially inward in the process. The face of the clamping element 8 can have teeth, so as to be twisted against the locking ring 24 .
[0046] During manufacture, the clamping element 8 is again pressed into the locking ring 23 , after which the central borehole 7 and possibly yet another axial face of the clamping element 8 and/or a face 25 of the locking ring 23 are finish-machined. The subsequent machining of the unit comprised of the machine element 2 and clamping element 8 results in a precise true running and, in the case of the locking ring 23 , avoids any wobbling impact of the face 25 .
[0047] The shaft-hub connection according to the embodiment encompasses a machine element 2 with a clamping element 8 , which forms a structural unit with the machine element 2 . The clamping element 8 has a central, preferably cylindrical borehole 7 for accommodating a shaft, and is thin-walled enough so that it can be defined radially inward. Its inner cylindrical bearing surface is preferably generated only once a molded blank provided to form the clamping element 8 has been securely placed in the machine element 2 . The machine element 2 provided with the clamping element 8 has a high clamping accuracy, and is easy and efficiently to manufacture.
[0048] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.
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A machine element is provided that includes, but is not limited to a clamping element without a slit, which is incorporated into a receiving area of the machine element. The clamping element has an opening for accommodating a shaft, and can be twisted against the machine element. A support sleeve is arranged radially outside relative to the clamping element. This makes the machine element easy to manufacture, convenient to use, and allows the absorption of high levels of force.
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RELATED APPLICATIONS
This patent application is a continuation-in-part application of co-pending U.S. patent application Ser. No. 60/785,753, filed Mar. 27, 2006, for Duo Use Sealing Tape Dispenser, by Hugh M. Lyman, Jr., included by reference herein and for which benefit of the priority date is hereby claimed.
FIELD OF THE INVENTION
This invention relates to tape dispensers, and more particularly to a dual use device for both hand-held and desk-top use that accommodates reels of tape of different core diameters.
BACKGROUND OF THE INVENTION
Adhesive tape dispensers, also referred to as sealing tape dispensers and packaging tape dispensers, are numerous and have been used for some time. Common tape dispensers are either, hand-held or desk-top. A problem with many tape dispensers is the awkward manipulations required to load a reel of adhesive tape. Considerable tape can be wasted loading tape reels into tape dispensers as it sticks to parts of the tape dispenser or itself. When long lengths of tape are extracted the tape can twist on itself, creating a tangled mess before it can be applied to an article.
Many of the popular tape dispensers used in mailing stores, offices, packaging rooms and mailing rooms are large and complicated mechanisms of considerable weight, but are hand-held. U.S. Pat. No. 5,197,386 issued to Lin, describes a device is made up of dozens of parts and is relatively heavy. This and other hand-held tape dispensers similar to U.S. Pat. No. 5,759,342 have a similar characteristic in that the tape end, when being applied to a package is a considerable distance from the operating hand, thereby limiting the control for positioning and cutting the tape being applied to the package. Further, as with many hand-held tape dispensers, when finished applying and cutting the tape, a flap of tape several inches long extends from the device, free to stick to places not desired.
Smaller hand-held tape dispensers are known in the art, as shown in U.S. Pat. No. 6,719,180 issued to Shah. This tape dispenser is small, light weight and economical, but is limited to use with only a single small reel of adhesive tape.
There are many desk-top tape dispensers. One design is illustrated in U.S. Pat. D504,155 issued to Crawford et al. Most of these types of dispensers are used mainly for narrow width masking tape. As common packaging tape is two inches wide and reasonably sticky, some effort is required to extract the tape from the tape reel. With this in mind, desk-top tape dispensers are either heavy or provided with suction cups to hold the dispenser stationary while tape is extracted.
Multiple roll tape dispensers are numerous as described in U.S. Pat. No. D399,257 issued to Tang et al. These tape dispensers, however are not designed for hand-held use.
Heretofore, prior art fails to address an adhesive backed tape dispenser that is light weight and can be used as a desk-top device and/or a hand-held device, is easy to load and provides a means where extracted tape is prevented from tangling or sticking to itself or other undesirable objects.
It is therefore an object of the invention to provide a tape dispenser that can be used as a desk-top device and/or a hand-held device.
It is another object of the invention to provide a simple tape dispensing device into which a reel of adhesive backed tape can be loaded easily and conveniently.
It is another object of the invention to provide a tape dispenser that dispenses adhesive backed tape quickly and easily.
It is another object of the invention to provide a tape dispenser that facilitates holding extracted tape with both hands to keep it from tangling.
It is another object of the invention to provide a tape dispenser that is light in weight.
It is another object of the invention to provide a tape dispenser that is of simple construction.
It is another object of the invention to provide a tape dispenser that is economical to produce.
It is another object of the invention to provide a tape dispenser that can accommodate different size reels of tape.
It is another object of the invention to provide a tape dispenser that can be conveniently clamped to a desk-top.
It is another object of the invention to provide a tape dispenser that prevents a loose tape end from becoming stuck to unintentional objects.
It is another object of the invention to provide a tape dispenser that can hold more than one roll of tape.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a tape dispensing device for dispensing and applying adhesive backed tape in a hand-held and/or desk-top configuration. Hand-held, the device is portable, the device being positioned appropriately by the operator. Desk-top, the device is stationary, conveniently at rest on a desk-top or work-top while tape is extracted by the operator.
The inventive device consists of two components: a base frame and a pivotal blade handle. The base frame is open on one side for conveniently threading the tape end to the desired configuration. The open side of the dispenser and the pivotal blade handle provides for convenient tape feeding. Pins positioned on the device hold a large diameter tape reel or up to two small diameter reels of tape for dual use thereof. Pin tabs on master pins hold the tape reels and restrict them from falling off of the dispenser. Further, the pin configuration allows easy turning of the tape reel while restricting the tape reel from free spooling. In the hand-held configuration the tape is fed through a gap between a pressure bar and the leading edge of a bottom plate. For the desk-top configuration the tape is fed under an upwardly pivotal blade handle and over a crossbar where the tape end extends beyond the provided crossbar. Scalloped finger grips on both side components provide for comfortably holding the device.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:
FIG. 1 is an isometric left side view of the tape dispensing device in accordance with the present invention;
FIG. 2 is an isometric right side view of the tape dispensing device;
FIG. 3 is an isometric left side expanded view of the tape dispensing device;
FIG. 4 is a top view of the present invention;
FIG. 5 is a front view of the present invention;
FIG. 6 is a back view of the present invention;
FIG. 7 is a section view of the tape dispensing device as taken along lines A—A in FIG. 4 with a large diameter reel of tape installed in the device;
FIG. 8 is a section view of the inventive tape dispensing device as taken along line A—A of FIG. 4 with two small diameter reels of tape mounted in position;
FIG. 9 is a perspective view of an alternate embodiment of the tape dispensing invention with rotating reel holders in place of an array of pin holders;
FIG. 10 is a perspective process view of the tape dispensing invention illustrating the tilting position of a reel of tape for mounting in the dispenser;
FIG. 11 is a perspective process view of the invention with the reel of tape further positioned onto the array of pin holders;
FIG. 12 is a perspective process view of the invention in the desk-top configuration with tape being extracted;
FIG. 13 is a perspective process view of the invention illustrating how the tape is cut in the desk-top configuration;
FIG. 14 is a perspective process view of a strip of tape held between two hands after being cut;
FIG. 15 is a perspective view of the invention illustrating how the device is clamped to a work-surface;
FIG. 16 is a process left side view of the tape dispenser showing a large diameter tape reel installed and the tape fed for hand-held use;
FIG. 17 is a perspective process view of the inventive device holding down the lids of a package to begin the application of tape to the package;
FIG. 18 is a perspective process view of the device moving across the package sealing the lids of the package;
FIG. 19 is a perspective process view of the inventive device at the position where the tape is cut after sealing the package;
FIG. 20 is a perspective process view of the invention illustrating how the tape end is secured after use, preventing it from sticking to other objects; and
FIG. 21 is a perspective process view of the invention illustrating how the tape is released when the operator is ready to use the device after storage in the hand-held configuration.
For purposes of clarity and brevity, like elements and components will bear the same designations and numbering throughout the figures. For purposes of brevity the ‘dual use tape dispenser’ will be referred to as ‘device’.
The following reference numerals are used to indicate the parts and environment of the invention.
20
device
100
base frame assembly
105
bottom plate
110
right side panel
115
left side arm
120
pressure bar
125
crossbar
135
axle pin
140
finger grips
145
finger notch
150
tape gap
152
bottom plate leading edge
155
tape retainer tab
160
tapered corner
165
gusset block
170
hand cutout
175
master pin
180
pin tab
185
master pin
190
pin tab
195
slave pin
197
slave pin
198
slave pin
199
rotating reel holder
200
blade handle assembly
210
blade handle arm
215
space
220
finger guard
230
finger grasp
240
slotted pin hole
250
cutting blade
260
cutting blade slot
300
large tape reel
305
small tape reel
306
medium tape reel
310
tape
320
tape reel core
330
cut tape end
340
cut tape end
410
thumb finger
420
index finger
430
thumb finger
440
index finger
500
package
510
package lid
520
spring clamp
530
desk-top
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description, taken in conjunction with the drawings, sets forth the preferred embodiment of the present invention in such a manner that anyone with ordinary skill can make and use the invention. The embodiment of the invention disclosed herein is the best method envisioned by the inventor for use in a home and office environment, although it should be understood that various modifications can be accomplished within the scope of the present invention.
Referring now to the drawings, and in particular to FIG. 1 , the device 20 comprises two assemblies: base frame assembly 100 which provides a stationary platform, and blade handle assembly 200 which provides for tape cutting.
The base frame assembly 100 comprises a bottom plate 105 rigidly connected orthogonally to a right side panel 110 , a crossbar 125 , a pressure bar 120 and an axle pin 135 , all rigidly connected orthogonally to the right side panel 110 . Further, a left side arm 115 is rigidly connected orthogonally to the crossbar 125 , the pressure bar 120 and the axle pin 135 . The left side arm 115 is provided with finger grips 140 . A gusset block 165 is rigidly connected to the bottom plate 105 and the right side panel 110 . In the forward portion of the bottom plate 105 is provided a finger notch 145 . A tape gap 150 is disposed between the bottom plate 105 and the pressure bar 120 . Rigidly connected orthogonally to the bottom plate 105 , and perpendicular to the bottom plate leading edge 152 is a tape retainer tab 155 . Rigidly, connected behind the axle pin 135 to the right side panel 110 is an array of spool pins to support a tape reel: top master pin 175 , bottom master pin 185 , slave pin 195 , slave pin 197 and slave pin 198 . At the ends of the top and bottom master pins 175 , 185 are rigidly connected pin tabs 180 , 190 , respectively. The device 20 can be made from wood, metal and/or plastic materials.
FIG. 2 illustrates the hand cutout 170 which accommodates the finger grips 140 in the right side panel 110 . Finger grips 140 are shown also on the left side arm 115 . The device 20 can be used either right- or left-handed.
FIG. 3 is an expanded view showing the blade handle assembly 200 separated from the base frame assembly 100 . The blade handle assembly 200 has two blade handle arms 210 . As evident to anyone skilled in the art, the blade handle assembly 200 may be of varying designs, such as configured to receive batteries and a thermo cutting blade, not shown. At the rear of the blade handle arms 210 are slotted pin holes 240 , wherein the blade handle assembly 200 pivotally attaches to the axle pin 135 and rests on the crossbar 125 in the closed position. The slotted portion of the slotted pin hole 240 is slightly undersized, wherein when the blade handle assembly 200 is snapped onto the axle pin 135 it is pivotally and removably connected to the base frame assembly 100 . The blade handle assembly rests on the crossbar in a closed position when cutting tape in both hand-held and/or desk-top configuration. To anyone ordinarily skilled in the art it would be apparent that the blade handle assembly 200 may be either permanently connected pivotally to the axle pin, by omitting the slot in the slotted pin hole.
The blade handle assembly 200 fits between and flush with the top edges of the right side panel 110 and left side arm 115 . At each front corner of the blade handle assembly 200 are protruding finger grasps 230 which fit to the tapered corners 160 of the base frame assembly 100 when the blade handle assembly 200 is closed.
Finger grasps 230 are flush with the outside faces of the right side panel 110 and left side arm 115 . The finger grasps 230 protrude beyond the position of the cutting blade 250 providing finger guards 220 . Disposed in the front edge of the blade handle assembly 200 is a cutting blade slot 260 for receiving and permanently holding the cutting blade 250 . Anyone with ordinary skill in the art would realize there are varying methods for attaching the cutting blade.
FIG. 4 is a top view of the preferred embodiment, illustrating clearly the length of the slave pins 195 , 197 , 198 which are shorter than the top and bottom master pins 175 , 185 . A space 215 is provided between the blade handle arms 210 and the right side panel 110 and left side arm 115 to allow the right side panel 110 and left side arm 115 to flex at the finger grips 140 and thereby provide a soft grip feature.
FIG. 5 is front view of the inventive tape dispenser illustrating the relative length of the slave pins 195 , 197 and 198 .
FIG. 6 is the back view of the inventive tape dispenser 20 . Here also is shown proportional length of the slave pins 195 , 197 , 198 in relation to the length of the top and bottom master pins 175 , 185 .
FIG. 7 is a sectional view of the preferred embodiment as taken along lines A—A in FIG. 4 with a large diameter tape reel 300 in position after being mounted. The dashed lines indicate the two options for feeding the tape 310 , wherein the top dashed line represents the tape 310 fed for the device 20 being used in the desk-top configuration and the bottom dashed line representing the configuration for hand-held use. With a large diameter tape reel 300 the device 20 can be configured for either hand-held or desk-top use.
FIG. 8 is the same sectional view as FIG. 7 with two small diameter tape reels 305 shown in place. The strategic position of the slave pins 197 , 198 affords easy installation of the small diameter tape reels 305 while preventing them from falling off of the device 20 when the device 20 is oriented or rotated while being used in the hand-held configuration.
The dashed line from the top front small tape reel 305 indicates feeding the tape 310 under the blade handle assembly 200 and over the crossbar 125 for the desk-top configuration. The dashed line from the rear bottom tape reel 305 indicates feeding the tape 310 down and through the tape gap 150 for hand-held use. With two small diameter tape reels 305 the device 20 can be used in either hand-held or desk-top configurations without changing the tape feeding position as is required with one large diameter tape reel 300 .
As evident to anyone ordinarily skilled in the art it would be evident that the device 20 may be constructed to also hold two large diameter tape reels 300 or constructed to hold one small diameter tape reel 305 and one medium diameter tape reel 306 or any combination thereof. Further it would be evident to anyone skilled in the art that rotating reel holders 199 could be substituted for the array of pins 175 , 185 , 195 , 197 , 198 as illustrated in FIG. 9 . The device 20 can hold two different diameter tape reels or even one large rotating reel holder.
FIG. 10 illustrates mounting the large tape reel 300 , it being positioned to mount to the device 20 . The large tape reel 300 is slightly tilted and placed over the pin tabs, 180 , 190 at the opposing quadrants at the inside of the tape reel core 320 . The large tape reel 300 is pressed over the pin tabs 180 , 190 on to the assembly at a tilted angle, the tape reel core 320 contacts the outside edge of slave pin 195 at an equal distance from the pin tabs, 180 , 190 and slips into a full locking position on the three pins 175 , 185 , 195 . The strategic position of master pins 175 , 185 and the slave pin 195 restrains the large tape reel 300 from falling off of the device 20 in any position. The large tape reel 300 can be as easily removed as it is installed. The placing of the small diameter tape reels 305 is accomplished in a similar manner but requires only two pins 175 , 198 for the top tape reel 305 and two pins 185 , 197 for the bottom tape reel 306 as shown in FIG. 8 .
FIG. 11 illustrates further the process of the large tape reel 300 as it is installed over the master pins 175 , 185 in a tilted position. At this position the pin tabs 180 , 190 are centered at the opposite quadrants of the tape core 320 . Once the slave pin 195 is engaged by the tape core 320 the large tape reel 300 is further pressed onto the device 20 . The slave pin 195 forces the tape reel core 320 off center on the master pins 175 , 185 allowing the outside edge of the large tape reel core 320 to snap inside the pin tabs 180 , 190 thereby preventing the large tape reel 300 from dislodging during use.
Referring to FIG. 12 illustrated is the process for extracting tape 310 from the device 20 in the desk-top configuration, whereby the tape dispenser is resting stationary on desk-top 530 (see FIG. 15 ). The distance between the cutting blade 250 and top of the crossbar 125 provides approximately one inch of loose cut tape end 330 ready for griping by the thumb 410 and the index finger 420 . The blade handle assembly 200 is pivoted up and out of the way with one hand gripping the finger grasps 230 , while the tape end 330 is pulled by the thumb 410 and the index finger 420 of the other hand extracting the tape 310 to the desired length.
The blade handle assembly 200 is then closed, as shown in FIG. 13 . With the heal of one hand resting on the blade handle assembly 200 , holding it closed, the index finger 440 of this hand extends over the finger guards 220 making contact with the adhesive side of the tape 310 . By pulling up on the tape 310 it is cut by the cutting blade 250 at the cut tape end 340 .
Referring to FIG. 14 the cut tape end 330 being held by the thumb 410 and the index finger 420 and the cut tape end 340 being held by the other hand thumb 430 and index finger 440 shows the tape being held tight and restricted from sticking to itself or an object until the user places it where desired. This process is very simple and fast.
FIG. 15 illustrates the device 20 clamped to a desk-top 530 with a spring clamp 520 . Clamping the device 20 to a desk-top 530 is not required with the device 20 configured for desk-top use, but may be convenient under some conditions.
Referring to FIG. 16 the tape 310 of large tape reel 300 is positioned for hand-held use. This process functions similar to other hand-held devices, however offers several advantages. The flat bottom of the device 20 makes it easy to hold down the package lids 510 of package 500 as shown with a down arrow in FIG. 17 . The tape end 330 is pressed against the end of the package 500 and with one hand the device 20 is pulled in a rearward motion, along the joint of the package lids 510 , shown in FIG. 18 . The tape retainer tab 155 shown in FIG. 16 prevents the tape 310 from inadvertently slipping out of the tape gap 150 while tap 310 is being extracted from the device 20 . The pressure bar 120 seals the tape 310 to the package lids 510 as the tape is applied. To anyone ordinarily skilled in the art it would be evident that the pressure bar 120 could be a rotating cylindrical roller as shown in prior art. As the hand is close to the tape 310 , control of the tape 310 is enhanced for easy positioning. At the opposite end of the package 500 (see FIG. 19 ) the device 20 is pulled down in the same horizontal position illustrated in FIG. 18 , applying tape 310 to the package 500 end. At the point desired for cutting the tape 310 with the cutting blade 250 , all that is required is a slight twist of the wrist of the hand holding the device 20 .
Referring to FIG. 20 , after the process of applying tape to a package 500 is completed and the device 20 is to be stored for future use, the tape end 330 is pulled back against the front edge of the bottom plate 105 at the tape gap 150 and stuck to the bottom of the bottom plate 105 , thereby safely keeping the tape end 330 from sticking to undesired objects while in storage. If at anytime the tape 310 between the large tape reel 300 and the tape gap 150 becomes slack within the device 20 , a gusset block 165 prevents the tape 310 from contacting itself where the adhesive side of the tape end 330 is exposed at the finger notch 145 . The next time the device 20 is used, the tape end 330 is released from the bottom of the bottom plate 105 with the thumb 410 and the index finger 420 at the finger notch 145 , as shown in FIG. 21 .
Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modification which do not constitute departures from the true spirit and scope of this invention.
Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.
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A dual use tape dispenser consisting of a base frame assembly and a cutting blade assembly pivotally connected to the base frame assembly. Integral with the base frame assembly is an array of pins positioned for holding different size reels of tape. Tape from reels of packaging tape is threaded in one and/or two ways so the tape dispenser can be used as a hand-held and/or a desk-top tape dispenser.
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FIELD OF THE INVENTION
[0001] The present invention concerns systems for storing energy and using the stored energy to generate electrical energy or drive a propeller.
BACKGROUND TO THE INVENTION
[0002] Electrical energy storage systems store base-load energy during off-peak periods and use the stored energy to provide electrical power during peak periods. Such systems are essential to the power generation industries. In conventional power generation systems, an energy storage system can provide substantial benefits including load following, peaking power and standby reserve. By providing spinning reserve and a dispatched load, electrical energy storage systems can increase the net efficiency of thermal power sources while reducing harmful emissions.
[0003] Electrical energy storage systems are critically important to intermittent renewable energy supply systems such as solar photovoltaic and wind turbine supply systems. This is due to the intermittent nature of the sources of renewable energy; the source is not always available over an extended period of time. Such a disadvantage has become an obstacle to the green electricity industry. Therefore, there is a need for a suitable energy storage system. Moreover, there is a need for the electricity storage system to be green.
[0004] Furthermore, electrical energy storage systems are regarded as a key technology in energy distribution networks with distributed generators, in order to compensate for any power fluctuation and to provide uninterruptible power supply during periods of voltage drop due to, for example, line faults.
[0005] Several electrical energy storage systems have been developed in the past. These include pumped hydro storage systems, Compressed Air Energy Storage systems (CAES), secondary batteries, Superconducting Magnetic Energy Storage systems (SMES), flywheels and capacitors.
[0006] Pumped hydro is the most widely used form of energy storage system. It stores hydraulic potential energy by pumping water from a lower reservoir to a higher reservoir. The amount of stored energy is proportional to the height difference between the two reservoirs and the volume of water stored. During periods of high demand for electricity, water falls from the higher reservoir to the lower reservoir through a turbine generator in a manner similar to traditional hydroelectric facilities. Pumped hydro storage is a mature technology with high efficiency, large volume, long storage period and relatively low capital cost per unit energy. However, a scarcity of available sites for two large reservoirs and one or more dams is the major drawback of pumped hydro. A long lead time for construction (typically ˜10 years) and environmental issues (e.g. removing trees and vegetation from the land prior to the reservoir being flooded) are two other major drawbacks of the pumped hydro system.
[0007] Compressed Air Energy Storage (CAES) is based on conventional gas turbine technology. It uses the elastic potential energy of compressed air. Energy is stored by compressing air in an air tight space such as underground storage cavern. To extract the stored energy, compressed air is drawn from the storage vessel, heated and then expanded through a high pressure turbine, which captures some of the energy in the compressed air. The air is then mixed with fuel and combusted, with the exhaust expanded through a low pressure turbine. Both the high and low pressure turbines are connected to a generator to produce electricity. CAES has a relatively high energy density, long storage period, low capital costs and high efficiency. In comparison with pumped hydro and other currently available energy storage systems, CAES is not an independent system. It requires combustion in the gas turbine. It cannot be used in other types of power plants such as coal-fired, nuclear, wind turbine or solar photovoltaic plants. In addition, the combustion of fossil fuels leads to emission of contaminates such as nitrogen oxides and carbon oxides which render the CAES less attractive. Also, similar to pumped hydro systems, CAES suffers from a reliance on favourable geography such as caverns. CAES can only be economically feasible for power plants that have nearby rock mines, salt caverns, aquifers or depleted gas fields. In addition, a major barrier for the CAES is the relatively low pressures that can be achieved, typically 40-60 bar.
[0008] Secondary battery systems are in some ways ideally suited for electrical energy storage systems. They not only provide fuel flexibility and environmental benefits, but also offer a number of important operating benefits to the electricity supply industry. They can respond very rapidly to load changes, and they can accept co-generated and/or third-party power, thus enhancing system stability. The construction of a secondary battery system is facilitated by short lead times, the lack of geographical limitations on location, and the technology's modularity. However, until recently, utility battery storage has been rare because of the low energy densities, high maintenance costs, short lifetimes, limited discharge capabilities and toxic remains associated with such systems. There are several new battery technologies now regarded as potentially competitive with pumped hydro and CABS systems including lead acid batteries, sodium sulphur batteries, zinc bromine batteries and redox flow batteries.
[0009] Superconducting Magnetic Energy Storage (SMES) is the only known method for the bulk storage of energy directly as electricity. SMES stores electrical energy as electric current passing through an inductor. The inductor, made from a superconducting material, is circular so that current can circulate indefinitely with almost no losses. SMES exhibits very high energy storage efficiency (typically 90%) and rapid respond (<1 second) relative to other energy storage systems. The major problems confronting the implementation of SMES units are the high cost and environmental issues associated with the strong magnetic fields employed.
[0010] Flywheel systems are a form of energy storage system that have been used for thousands of years. The disadvantages of these systems are their short duration, relatively high frictional losses (windage) and low energy densities. Traditional flywheel systems with conventional metal rotors lack the necessary energy density to be considered seriously for large-scale energy storage applications. Recent advances in material science have started to change this picture. In particular, the development of low-density, high-strength, fibre-composite materials has allowed the design and construction of flywheel energy storage systems with a comparable energy density to other systems. Also, new bearing technologies are being developed, such as levitation bearings using high temperature superconductors which have the potential of reducing the windage losses that account for a large portion of the total energy loss.
[0011] Capacitors are a form of energy storage system that have been used for many years in the electronics industry. Double layer capacitors have been developed for a daily peak load in the summer of less than 1 hour with small capacities. Recent progress in the field of redox super capacitors could lead to the development of larger capacity systems. The major disadvantages of capacitors as energy storage systems are, similar to flywheels, their short duration and high energy dissipation due to self-discharge loss.
[0012] Accordingly, there is a need for an electrical energy storage system which has high energy density and potential output power, high energy efficiency, a long duration, a long lifetime, low capital costs, and offers a good commercial potential. The system should preferably be capable of being used with current power plants without requiring major modifications to the power plants except to the inputs and outputs for electricity. The system should also preferably be capable of working completely separately from the power plant. Start-up and suspension of the system should preferably be simple and reliable and the system should preferably be capable of being used with most types of existing medium to large scale power plants including coal-fired, gas turbine, nuclear, wind turbine and solar photovoltaic plants, irrespective of the geographical location of the plants. The system should also preferably not be detrimental to the environment, particularly by using the process in conjunction with non-polluting power plants (a Zero Emission System), and may even have the potential to reverse environmental impacts associated with the burning of fossil fuels.
[0013] The inventors of the present invention have attempted to provide an electrical energy storage system that addresses these requirements.
[0014] In addition, there is also a need for an improved environmentally friendly maritime power system for providing propulsion for boats. Environmental concerns arise constantly in the maritime sector with regard to both water and air pollution.
[0015] A typical power system for boats consists of main propulsion engines, propellers, donkey engines/generators, boilers, transition and control systems etc. The main propulsion engine is the most important component. Several types of main propulsion engines have been developed in the marine sector including steam turbine, diesel engines, gas turbine and nuclear engines. Among these types, diesel engines are the most widely used and occupy ˜90% of the total current power capacity. However, all these engines have environmental problems. Diesel engines, steam turbines and gas turbines need to combust fossil fuels. Contaminates (e.g. CO 2 , NO x and particulates) are inevitably produced in combustion processes. Nuclear power systems not only produce nuclear waste pollution and provide a radiation risk but also are at least an order of magnitude more expensive than other power systems.
[0016] Consequently, a combustion free power system with a non-polluting exhaust would be greatly welcomed by the marine industry and the general public. It would also be desirable if such a marine power system could be used to generate electricity for use within the boat and to heat and/or cool the boat as necessary.
SUMMARY OF THE INVENTION
[0017] The present invention concerns the use of a cryogenic working fluid for energy storage, energy generation and propulsion.
[0018] A cryogenic energy storage (CES) system according to an embodiment of the present invention stores a cryogen produced using electricity during off-peak hours, thus storing energy, and uses the stored cryogen to generate electricity during peak hours, thus releasing the stored energy. The cryogen may be pumped, heated and then expanded in a turbine.
[0019] Accordingly, the present invention provides a method of storing energy comprising:
providing a gaseous input; producing a cryogen from the gaseous input; storing the cryogen; expanding the cryogen; using the expanded cryogen to drive a turbine; and recovering cold energy from the expansion of the cryogen.
[0026] The present invention also provides a cryogenic energy storage system comprising:
a source of cryogen; a cryogen storage facility; means for expanding the cryogen; a turbine capable of being driven by the expanding cryogen; and means for recovering cold energy released during expansion of the cryogen.
[0032] The turbine may be used to drive a generator and thus generate electricity.
[0033] Alternatively, or in addition, the turbine may be used to drive a propeller for example for use in a marine engine. Consequently, the CES may be used as a Cryogenic Propulsion System (CPS).
[0034] The turbine may comprise a multi-stage quasi-isothermal turbine. The turbine may include reheaters or interheaters.
[0035] A number of suitable cryogens may be used. Preferably, the cryogen comprises liquid air. Alternatively, the cryogen may comprise slush air, liquid nitrogen, liquid hydrogen, liquid natural gas (LNG) or any other cryogen.
[0036] The energy storage system may maximise the use of, and minimise the modification of, current available and mature technologies for cryogen formation, such as air liquefaction plants.
[0037] If the cryogen comprises liquid air, the liquid air may be produced by an air liquefaction plant and supplied to the CES at off-peak hours. In the meantime, other products such as O 2 , N 2 , Ar and CO 2 in both gas and liquid states could be produced as commercial products if needed. The efficiency of the production of the cryogen may be improved by using waste cold from other sources such as from the regasification of LNG (liquid natural gas).
[0038] Modern large capacity cryogenic oxygen production plants have low running costs of ˜0.4 kWh/kg (1.44 MJ/kg). This cost is expected to decrease further to ˜0.3 kWh/kg (1.08 MJ/kg) by 2010-2020 (“Air separation and liquefaction: recent developments and prospects for the beginning of the new millennium”, Castle W. F., International Journal of Refrigeration, 25, 158-172, 2002; “Energy analysis of cryogenic air separation”, Cornelissen R. L. and Hirs G. G., Energy Conservation and Management, 39, 1821-1826, 1998). The CES may use a feedstock of liquid air from a cryogenic plant but will work completely separately from the cryogenic plant; this feedstock may be small depending on the ‘cold energy’ recycle and operation strategy. The production of liquid air may consume about 80% of the energy required to produce liquid oxygen given present production methods.
[0039] The cryogen may be expanded by heating. For example, the cryogen may be heated by thermal sources including ambient, geothermal, waste heat from power plants and/or other waste heat resources to heat the cryogenic working fluid and generate electricity during peak hours. The thermal sources may not previously have been utilised for electricity generation because the temperature difference between the working fluid and heat source would have been considered insufficient. The working fluid may be superheated by the waste heat. The waste heat may have originated from power plants or from the compression process of the input gas or even from the waste gas stream after being heated to ambient temperature by ambient air. To increase the energy density of the working fluid, the gaseous input may be at a high pressure before expansion because the ideal work per unit mass of gaseous input for an isothermal expansion for an ideal gas, W T , is given by
[0000]
W
T
=
RT
ln
(
P
in
P
out
)
[0000] where R, T, P in and P out are the universal constant, gas temperature, and injection and exhaust pressures, respectively. Moreover, the cryogen may be pumped as a liquid to a high working pressure because little work is consumed in the pressurization of liquid. On the other hand, the gas temperature may be as high as possible before expansion. Use could be made of the waste heat contained in the flue gas from power plants for heating the cryogen. Most effectively, the ambient air could be used to heat the cryogen to approximately the environmental temperature and the waste heat could then be used to heat the working fluid further to improve the energy efficiency of the entire system. Because the temperature difference between the cryogen and ambient temperature is high, waste heat which previously would have been considered a poor source of energy can be used as a source of energy to heat the cryogen.
[0040] By using the waste heat, the CES can be used as a net energy generator. Therefore, the CES can operate as a stand-alone energy storage plant using electricity as an energy input along with ambient temperature heat from the atmosphere. The CES can be placed either at the point of generation or the point of demand.
[0041] The ‘cold’ energy contained in the cryogen as the working fluid is very high-grade cryogenic energy and at least a portion is recycled. In a preferred embodiment the ‘cold’ energy contained in the working fluid is extracted to cool down the gaseous input (before and/or after a compressor, a fan or a blower) through heat exchangers. The cold energy may be extracted from the exhaust gas from the system. Assuming that the cryogen is heated to the ambient temperature in an isobaric process before expansion, the heat absorbed from the atmosphere by the cryogen is given by Q=h 0 −h l where h 0 and h l are enthalpy at ambient temperature and at liquid temperature, respectively. Considering a Carnot cycle operated between a low temperature reservoir at T l =78.9K and a high temperature reservoir at an ambient temperature of T 0 =300K, the amount of work is given by
[0000]
W
=
Q
(
T
0
T
1
-
1
)
.
[0000] Therefore the amount of work is proportional to the temperature difference. The above equation also implies that the work required to achieve the cold energy Q is equivalent to several multiples of the cold energy, which should therefore be used effectively.
[0042] The input air can be compressed before, after or at the same time as passing through the heat exchangers depending on applications. Therefore, the compressor can be positioned either before the heat exchanger, after the heat exchanger, or even within the heat exchanger. If the cold air is to be used for air-conditioning or cooling of food and other products, then it is preferable for compression to be realised by a blower (low pressure) located before the heat exchangers. Alternatively, if the input air is used for producing liquid cryogen, then it is preferable for a compressor to be placed after the heat exchangers. Such a compressor could be a stand-alone compressor attached to the CES if the liquifaction plant is remote to the CES. Alternatively, if the CES is adjacent to the liquefaction plant, then the compressor of the liquefaction plant could be used.
[0043] If the cold cryogen is used to cool the gaseous input, the cooled gaseous input can then feed back into the cryogen plant as a feedstock or be liquefied to cryogen inside the CES.
[0044] In addition, or alternatively, the cold energy may be used to provide cooled air for refrigeration or air conditioning purposes. For example, in a maritime power system, the energy storage system can be used to drive a turbine to drive a propeller as well as to provide cooled air for air conditioning and/or refrigeration purposes.
[0045] Alternatively, or in addition, waste heat from the system could be used to provide heat to the immediate environment, e.g. to provide heating and/or hot water in a boat.
[0046] The present invention may make simultaneous use of ‘cold’ energy and ‘waste’ heat. By recovering the ‘cold’ energy from the expansion of the stored cryogen and using it to enhance the production of more cryogen whilst the system is operating in electricity generation mode, the efficiency of the system as a whole is increased. Cold energy is as useful in this system as hot energy. In addition the CES uses energy in the ambient air (heat) or water to heat the cryogen to close to the ambient temperature, followed by further heating with waste heat from, for example, flue gas and steam venting to the environment from a power generation plant. Also, heat released from the compression of gaseous input can also be recovered and used to heat the cryogen. The heat applied to the cryogen causes it to expand and this drives the cryogen.
[0047] As heat losses and hydraulic pressure drops always occur, the pressure of the gaseous input may be increased either before or after the one or more heat exchanger, for example at the inlet, using, for example, a blower or a compressor. The compression process could be adiabatic or isothermal. Assuming the ideal behaviour of air, the work required for the isothermal process is given by
[0000]
W
T
=
RT
ln
(
P
1
P
0
)
[0000] whereas that for the adiabatic process, W Q , is given by
[0000]
W
Q
=
h
1
-
h
0
=
k
k
-
1
RT
0
[
(
P
1
P
0
)
(
k
-
1
)
k
-
1
)
]
[0000] where k, P 1 , P 0 are the specific heat ratio (=1.4 for air), and the outlet and inlet pressures of the compressor or blower, respectively. Therefore, the required work increases with increasing outlet pressure P 1 . Therefore, P 1 should be kept as low as possible to save compression work.
[0048] Waste heat from the compressor could be used to provide heat to the immediate environment, for example, to provide heating and/or hot water in, for example, a boat.
[0049] In a preferred embodiment the cryogen production plant may be integrated with the energy storage system. Alternatively, the cryogen production plant may be remote from the energy storage system and the cryogen could be transported between the two plants.
[0050] A small amount of cryogen may be needed to top up the system after each cycle.
[0051] When a non-polluting source of energy is used to power the system, the system is environmentally benign with a potential to reverse environmental contamination by separating environmentally detrimental gases, such as CO 2 and other contaminants, associated with the burning of fossil fuels from the gaseous input.
[0052] The system of the present invention does not involve any combustion process so it will not cause any emissions. The only working fluid is the cryogen. The effect on the environment is also minimised because less CO 2 and other environmentally detrimental gas components such as NO X are produced or used.
[0053] The CES system can be used for storing energy produced from most existing power generation plants.
[0054] When the CES is configured as a CPS, the system can be used as a propulsion device instead of in a static energy storage or generation system. The CPS could therefore be used in a boat engine. The CES could be configured to drive both a propeller and a generator so that the power system could be used to both provide propulsion and electricity for a boat.
[0055] In addition, the CPS could be further configured to provide heat for heating a boat and/or its contents. The CPS could also be further configured to provide cold for refrigeration purposes on board the boat, or for air conditioning of the boat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] The present invention will now be described in more detail with reference to the following figures in which:
[0057] FIG. 1 shows a schematic diagram of an energy storage system according to the present invention;
[0058] FIG. 2 shows a schematic diagram of a cryogenic air separation and liquefaction plant;
[0059] FIG. 3 shows a schematic diagram of a CES according to the present invention;
[0060] FIG. 4 shows a schematic diagram of a CPS according to the present invention;
[0061] FIG. 5 shows an ideal T-S diagram of a CES according to the present invention for an ambient pressure case;
[0062] FIG. 6 shows a practical T-S diagram of a CES according to the present invention for an ambient pressure case;
[0063] FIG. 7 shows a practical T-S diagram of a CES with superheating according to the present invention for an ambient pressure case;
[0064] FIG. 8 shows a T-S diagram of a CES according to the present invention for a low pressure ratio case;
[0065] FIG. 9 shows a T-S diagram of a CES according to the present invention for a high pressure ratio case;
[0066] FIG. 10 a shows a thermodynamic cycle for a CPS according to the present invention;
[0067] FIG. 10 b shows a thermodynamic cycle for a CPS according to the present invention when the pressure of the input air 1 exceeds 38 bar.
[0068] FIG. 11 shows four efficiencies of the thermodynamics cycles associated with a CES according to the present invention when the input air pressure, P 1 , is 0.1 MPa;
[0069] FIG. 12 shows four efficiencies of the thermodynamics cycles associated with a CES according to the present invention when the input air pressure, P 1 , is 0.2 MPa;
[0070] FIG. 13 shows four efficiencies of the thermodynamics cycles associated with a CES according to the present invention when the input air pressure, P 1 , is 0.4 MPa;
[0071] FIG. 14 shows four efficiencies of the thermodynamics cycles associated with a CES according to the present invention when the input air pressure, P 1 , is 1.0 MPa;
[0072] FIG. 15 shows four efficiencies of the thermodynamics cycles associated with a CES according to the present invention when the input air pressure, P 1 , is 2.0 MPa;
[0073] FIG. 16 shows four efficiencies of the thermodynamics cycles associated with a CES according to the present invention when the input air pressure, P 1 , is 4.0 MPa;
[0074] FIG. 17 shows four efficiencies of the thermodynamics cycles associated with a CES according to the present invention when the input air pressure, P 1 , is 10 MPa;
[0075] FIG. 18 shows four efficiencies of the thermodynamics cycles associated with a CES according to the present invention when the input air pressure, P 1 , is 20 MPa;
[0076] FIG. 19 shows the actual efficiencies of a CES according to the present invention without superheating when the pressure of the working fluid is 20 MPa;
[0077] FIG. 20 shows the actual efficiencies of a CES according to the present invention with superheating when the pressure of the working fluid is 20 MPa;
[0078] FIG. 21 shows efficiencies of a CES according to the present invention at different turbine efficiencies when no waste heat is used;
[0079] FIG. 22 shows efficiencies of a CES according to the present invention at different turbine efficiencies when waste heat is used;
[0080] FIG. 23 shows efficiencies of a CES according to the present invention at different compressor efficiencies when no waste heat is used;
[0081] FIG. 24 shows efficiencies of a CES according to the present invention at different compressor efficiencies when waste heat is used;
[0082] FIG. 25 shows efficiencies of a CES according to the present invention at different pump efficiencies when no waste heat is used;
[0083] FIG. 26 shows efficiencies of a CES according to the present invention at different pump efficiencies when waste heat is used;
[0084] FIG. 27 shows efficiencies of a CES according to the present invention at different energy consumptions of cryogen when no waste heat is used;
[0085] FIG. 28 shows efficiencies of a CES according to the present invention at different energy consumptions of cryogen when waste heat is used;
[0086] FIG. 29 shows efficiencies of a CPS according to the present invention as a function of the pressure of input air 1 ;
[0087] FIG. 30 shows efficiencies of a CPS according to the present invention as a function of the ambient temperature;
[0088] FIG. 31 shows efficiencies of a CPS according to the present invention as a function of the efficiency of the turbine;
[0089] FIG. 32 shows efficiencies of a CPS according to the present invention as a function of the efficiency of the compressor;
[0090] FIG. 33 shows efficiencies of a CPS according to the present invention as a function of the efficiency of the pump;
[0091] FIG. 34 shows efficiencies of a CPS according to the present invention as a function of the polytropic coefficients of the compressor;
[0092] FIG. 35 shows efficiencies of a CPS according to the present invention as a function of the isothermicity of expansion;
[0093] FIG. 36 shows efficiencies of a CES according to the present invention as a function of temperature differences between hot and cold fluids in the heat exchanger when no waste heat is used;
[0094] FIG. 37 shows efficiencies of a CES according to the present invention as a function of temperature differences between hot and cold fluids in the heat exchanger when waste heat is used;
[0095] FIG. 38 shows efficiencies of a CES according to the present invention as a function of the temperature of the waste heat used;
[0096] FIG. 39 shows efficiencies of a CES according to the present invention as a function of the ambient temperature;
[0097] FIG. 40 shows efficiencies of a CPS according to the present invention as a function of the temperature difference between hot and cold fluids in a heat exchanger;
[0098] FIG. 41 shows efficiencies of a CPS according to the present invention as a function of time;
[0099] FIG. 42 shows an exemplary small lab scale CES system according to the present invention;
[0100] FIG. 43 shows a T-S diagram of the CES experimental system of FIG. 42 ;
[0101] FIG. 44 shows the work output of a turbine for use in the CES of FIG. 42 as a function of the number of stages;
[0102] FIG. 45 shows the expansion ratio of each stage of a turbine for use in the CES of FIG. 42 as a function of the number of stages;
[0103] FIG. 46 shows a suitable cryogenic tank for use with the CES of FIG. 42 ;
[0104] FIG. 47 shows a suitable pump for use with the CES of FIG. 42 ;
[0105] FIG. 48 shows a suitable turbine for use with the CES of FIG. 42 ;
[0106] FIG. 49 shows the characteristics of the output power and the output duration of a number of energy storage systems;
[0107] FIG. 50 shows the relationship between the efficiency and the cyclic period for a number of energy storage systems;
[0108] FIG. 51 shows the energy storage densities of a number of different energy storage systems; and
[0109] FIG. 52 shows the relationship between the output power per capital cost and the storage energy capacity per unit capital cost for a number of different energy storage systems.
DETAILED DESCRIPTION OF THE INVENTION
[0110] A conceptual design of the energy storage system of the present invention is shown in FIG. 1 . The whole system is shown within dotted box 100 . System 100 consists of two major parts: an air liquefaction part 200 , and a Cryogenic Energy Storage unit (CES) 300 . In off-peak hours, surplus electricity is fed to the air liquefaction plant 200 to produce liquid air, which is then used in peak hours by the CES 300 to generate electricity. The power plant 400 and the whole energy storage system 100 only have to exchange electricity, so no modification of the power plant 400 is needed thus ensuring maximum flexibility. At the same time, any available waste heat 410 from the flue gas of the power plant 400 can be used by the CES 300 to heat the working fluid.
[0111] Within the energy storage system 100 , there are two major air streams. One stream 110 feeds air to the air liquefaction plant 200 to be liquefied and stored as liquid air in a cryogen tank. During peak time the liquid air is pumped, heated and then expanded in the CES 300 to generate electricity. Another air steam 120 is input air from the atmosphere. Input air 120 is fed to the CES 300 to supply heat for expansion of the working liquid air and to extract the ‘cold’ energy from the working liquid air. The cooled input air 130 can be directed to the air liquefaction plant 200 as a feedstock or be throttled to produce liquid air within the CES 300 to reduce the amount of cryogen required from the air liquefaction plant 200 . At the same time, the air liquefaction plant 200 can produce other products 210 such as N 2 , O 2 , CO 2 , Ar etc if needed.
[0112] The cryogenic air liquefaction system 200 is a mature technology and many types of cryogenic air liquefaction systems are readily available “off-the-shelf”. FIG. 2 shows a schematic diagram of a typical air liquefaction plant. A liquefaction plant consists of 5 major units: an air compression unit 220 , an air pre-treatment unit 230 , an air cooling unit (not shown), a cooling unit (not shown), and a rectification unit (not shown) (the rectification unit is only needed if air is to be separated into different products). The air pre-treatment unit 230 is downstream of the air compression 220 and cooling units and is for removing contaminants such as water, carbon dioxide, and hydrocarbons. The purified air is then further cooled down to the cryogenic temperature using heat exchange 240 and distilled. If needed, it is passed through the rectification unit to produce, for example, oxygen, nitrogen, or argon as gas or liquid products. If necessary (i.e. for air products production), the products can be warmed up with the feed air to conserve the refrigeration, with any deficit made up by expanding a small portion of pressurised air.
[0113] A CES 300 according to the present invention is shown in FIG. 3 . The CES 300 comprises eight main components: compressor 310 , turbine 320 , generator 330 , first heat exchanger 340 , second heat exchanger 350 , throttling valve 360 , cryogen tank 370 and pump 380 .
[0114] Liquid air 250 from a cryogenic plant is introduced into the cryogen tank 370 (in state 5 in FIG. 3 ) to be pumped by pump 380 to a certain pressure (state 7). The pressurised liquid air is heated in the second heat exchanger 350 (state 8) and then superheated in the first heat exchanger 340 (state 9). The liquid aid, as a working fluid, then expands to drive the turbine 320 and generator 330 . The turbine 320 may be a multi-stage gas turbine with a continuous heat supply in order to achieve a nearly isothermal expansion. After expansion and powering of the generator 330 , there are three options for the working fluid (state 10):
1) to be vented directly to the atmosphere and/or used for cooling or refrigeration, 2) to be fed back into the air liquefaction plant 200 as feedstock 3) to be introduced into the power plant 400 .
[0118] There are three possible benefits in adopting option 3 : recovery of lower grade heat, if usable, from the exhaust of the turbine; injection into the combustion chamber of the turbine to reduce NO x ; and increasing the power output of the gas turbine as the injected air can act as a diluent that permits greater fuel consumption without exceeding the turbine inlet temperature limits. These benefits may be marginal but could bring the overall efficiency up if effectively used.
[0119] In the input air stream 120 , air from the environment (state 0) is compressed (state 1) using compressor 310 and introduced to the first heat exchanger 340 (state 2) for use in heating up the working fluid. The compressor may be a multi-step compressor to approach an adiabatic compression. Some unwanted components in the input air such as water (which is bad for the turbine due to cavitation), carbon dioxide, NO and hydrocarbons can also be removed during this process.
[0120] The cleaned input air then goes through the second heat exchanger 350 (state 3) to extract more ‘cold energy’ from the working fluid.
[0121] The cooled input air is then either fed to the liquefaction plant 200 as feedstock or to the throttling valve 360 to be transformed into liquid air (state 4) for top-up of the cryogen tank 370 . A small proportion of air after the throttling is in the gas state but is still at low temperature (state 6). This part of cold energy is recovered by introducing the gas back into the second heat exchanger 350 . This part of the air may be rich in oxygen so it can further be used, for example, as an oxidant in a gas turbine or a coal-gasification turbine.
[0122] The first heat exchanger 340 may be an integrated heat exchanger so that two parallel heat exchanging processes occur, namely between the input air and the working fluid, and between the working fluid and the (relatively) high temperature flue gas from the power plant. The first heat exchanger 340 may alternatively be designed as two separate heat exchangers, one for each of these two processes.
[0123] FIG. 4 shows a cryogenic propulsion system (CPS) 500 according to the present invention. The CPS is based on the powered propeller type and could offer simultaneously cold, heat, propulsion and electricity. A CPS according to the present invention consists of eleven major components: a propeller 505 , a turbine 510 , a generator 515 , a compressor 520 , four heat exchangers 525 , 530 , 535 , 540 , a throttling valve 545 , a cryogen tank 550 and a pump 555 .
[0124] The working processes of the CPS system 500 comprise:
1) The liquid air from a cryogen plant or storage depot is fed into the cryogen tank 550 . 2) After being pumped, heated and superheated, the working fluid expands to drive propeller 505 and/or generator 515 to provide propulsion and/or electricity. 3) At the same time, an air stream from the atmosphere (input air 1 ), is compressed and introduced to the heat exchangers 525 , 530 , 535 , 540 . The compression heat contained in input air 1 can be extracted via heat exchanger 525 to provide hot water/hot air for the boat. The input air 1 then extracts the cold from the working fluid while flowing through heat exchangers 530 , 535 , 540 . Finally, the input air 1 is throttled to produce liquid air and stored in the cryogen tank 550 . 4) Input air 2 and water at the ambient temperature are introduced into heat exchanger 525 to extract the compression heat contained in the input air 1 to produce hot air/water as mentioned above.
[0129] Input air 3 / 4 under ambient conditions is introduced to extract cold energy via heat exchangers 530 and 535 to provide cool air for air conditioning (12˜18° C., from heat exchanger 530 ) and refrigeration (−24˜−18° C., from heat exchanger 535 ).
Thermodynamics Cycle Analysis—CES
[0130] Four typical cycles for the CES system of FIG. 3 are considered in terms of the input air pressure, two at ambient conditions, one at low pressure and one at high pressure. In the analyses, liquid air is treated as a single phase fluid and the gaseous air as an ideal gas. The energy losses in the compressor 310 , turbine 320 , pump 380 and throttle valve 360 are accounted for by using efficiencies q. For these thermodynamic analyses, the frictional and regional losses due to flow in pipes, valves and bends are ignored and dissipation of cryogen during storage are not considered. The ambient temperature and pressure are expressed by T 0 and P 0 , respectively; the critical and boiling temperatures of liquid air are denoted as T cr and T S , respectively.
Ambient Input Air Pressure Case—Ideal Thermodynamics Cycle Analysis
[0131] The ideal thermodynamics cycle is shown in FIG. 5 . The processes and the work, heat and/or exergy of these processes are:
[0000] 1) Process 5-7, Pumping process of working fluid: The working fluid (liquid air) from the cryogen tank is pumped from ambient pressure P 0 to P 2 adiabatically. The specific work (work per unit mass of liquid air) can be expressed by:
[0000]
W
5
-
7
=
V
l
(
P
2
-
P
0
)
=
(
P
2
-
P
0
)
ρ
l
[0000] from the viewpoint of fluid mechanics. The work can also be expressed by the enthalpy difference between states 7 and 5 from the first law of thermodynamics: W 5-7 =h 7 −h 5 .
2) Process 7-8, Isobaric heating of working fluid: The working fluid is heated by the input air from T s to the ambient temperature T 0 . The specific work done in this process is zero: W 7-8 =0. The specific heat absorbed by the working fluid from input air is: Q 7-8 =h 8 −h 7 . The exergy loss of the process is therefore: Ex 7-8 =T 0 (S 8 −S 7 )−(h 8 −h 7 ).
3) Process 8-0, Isothermal expansion of the working fluid: The working fluid at the high pressure expands in the turbine, which drives the generator to generate electricity at the ambient temperature T 0 . The specific ideal work done by the turbine in this process is given by: W 8-0 =T 0 (S 0 −S 8 )−(h 0 −h 8 ). The specific heat absorbed during the expansion by the working fluid from the atmosphere is: Q 8-0 =T 0 (S 0 −S 8 ).
4) Process 0-6, Extraction of cold energy from the work fluid by the input air: The input air is used to extract the cold energy from the work fluid isobarically. No work is needed in theory in this process: W 0-6 =0. The specific cold absorbed by the input air from the working fluid is: Q 0-6 =h 6 −h 0 . The exergy obtained by the input air over the process is given by: Ex 0-6 =T 0 (S 0 −S 6 )−(h 0 −h 6 ).
5) Process 6-5, Condensation of input air: The input air is condensed by the cold exergy released by the work fluid, which requires zero work to be done: W 6-5 =0. The specific cold energy absorbed by the input air from the work fluid is: Q 6-5 =h 5 −h 6 =λ where λ is the latent heat of vaporisation. The corresponding exergy obtained by the input air is: Ex 6-5 =T 0 (S 6 −S 5 )−(h 6 −h 5 ). Assuming the mass flow of work fluid is 1, the mass flow of the input air is x, then a heat balance gives: Q 7-8 ≧x(Q 0-6 +Q 6-5 ) where Q 7-8 =h 8 −h 7 , Q 0-6 =h 6 −h 0 and Q 6-5 =h 5 −h 6 . Inserting these expressions into the above equation gives: h 8 −h 7 ≧x(h 0 −h 5 ). If P 2 is given, then h 8 , h 7 , h 0 , h 5 can be determined and x can be expressed by:
[0000]
x
≤
(
h
8
-
h
7
)
(
h
0
-
h
5
)
.
[0000] According to the second law of thermodynamics, exergy of a system can only decrease without input energy, that is: Ex 7-8 ≦x(Ex 0-6 +Ex 6-5 ),
[0000]
x
≤
Ex
7
-
8
(
Ex
0
-
6
+
Ex
6
-
5
)
.
[0000] Therefore, the consumption of liquid air for a single cycle is (1−x) and the specific net work output of the cycle should be: W net =W 8-0 −W 5-7 =(S 0 −S 8 )−(h 0 −h 8 )−(h 7 −h 5 ) and the energy density of CES can be expressed by:
[0000]
E
D
=
W
net
1
-
x
=
T
(
S
0
-
S
8
)
-
(
h
0
-
h
8
)
-
(
h
7
-
h
5
)
(
1
-
x
)
.
[0000] Assuming that the energy consummation of the liquid air produced in the air liquefaction plant is E C , the energy efficiency of the whole energy storage system (Air liquefaction+CES), E E , can be calculated by:
[0000]
E
E
=
E
D
E
C
.
[0000] Considering the efficiency of pump η P and the efficiency of turbine η T , the net work W net should become:
[0000]
W
net
′
=
η
T
W
8
-
0
-
1
η
P
W
5
-
7
=
η
T
[
T
(
S
0
-
S
8
)
-
(
h
0
-
h
8
)
]
-
(
h
7
-
h
5
)
η
P
.
[0000] The energy density of CES E D becomes:
[0000]
E
D
′
=
W
net
′
1
-
x
=
η
T
[
T
(
S
0
-
S
8
)
-
(
h
0
-
h
8
)
]
-
(
h
7
-
h
5
)
η
P
(
1
-
x
)
.
[0000] E E becomes:
[0000]
E
E
=
E
D
′
E
C
.
[0000] However, the temperature difference between the working liquid and the input air cannot be avoided. This will decrease the temperature T 8 and increase the temperature T 6 . Therefore, the ideal thermodynamics cycles overpredict the overall efficiency of the system. This is accounted for in the following, with reference to FIG. 6 .
Ambient Input Air Pressure Case—Practical Thermodynamics Cycle Analysis
[0132] In FIG. 6 , the working liquid can only be heated to T 8′ , owing to the existence of a temperature difference from the ambient temperature, and input air can only be cooled down to T 6′ . Because T 6′ is higher than T 6 (the boiling temperature) the input air needs to be liquefied in the air liquefaction plant, and then fed back to the CES system at state 5.
[0133] The work, heat and/or exergy related to the processes shown in FIG. 6 are given in the following:
[0000] 1) Process 5-7, Pumping process of working fluid: This process in FIG. 6 is the same as that shown in FIG. 5 . Liquid air from the cryogen tank is pressurised by the pump from ambient pressure P 0 to P 2 . The specific work done on the liquid air is:
[0000]
W
5
-
7
=
V
l
(
P
2
-
P
0
)
=
(
P
2
-
P
0
)
ρ
l
[0000] which is equal to the enthalpy difference between state 7 and state 5: W 5 −7=h 7 −h 5 .
2) Process 7-8′, Isobaric heating of working fluid: The working fluid is heated by the input air from T s to T 8′ instead of ambient temperature T 8 (=T 0 ). The specific work done in this process is zero: W 7-8 =0. The specific heat absorbed by the working fluid from input air is: Q 7-8′ =h 8 −h 7 . The exergy loss in the process is therefore: Ex 7-8′ =T 0 (S 8′ −S 7 )−(h 8′ −h 7 ).
3) Process 8′-0′, Isothermal expansion of the working fluid: The working fluid at a high pressure expands in the turbine, which drives the generator isothermally to produce electricity. The specific ideal work done by the turbine in this process is: W 8′-0′ =T 0′ (S 0′ −S 8′ )−(h 0′ −h 8′ ). The specific heat absorbed during the expansion by the working fluid from the atmosphere is: Q 8′-0′ =T 0′ (S 0′ −S 8′ ).
4) Process 0-6′, Extraction of cold energy from the work fluid by the input air: The input air is used to extract the cold from the work fluid isobarically. The specific work done in this process is zero, i.e: W 0-6′ =0. The specific cold extracted from the work fluid by the input air is: Q 0-6′ =h 6′ −h 0 . The exergy obtained by the input air in the process is therefore given by: Ex 0-6′ =T 0 (S 0 −S 6′ )−(h 0 −h 6′ ).
5) Process 6′-6-5, Cooling and Condensation of input air: The input air is cooled and condensed in the air liquefaction plant. Assuming the mass flowrate of working fluid is 1, the mass flowrate of input air is x, heat balance of the cycle gives: Q 7-8′ ≧xQ 0-6′ where Q 7-8′ =h 8′ −h 7 , Q 0-6′ =h 6′ −h 0 the above equation becomes: h 8′ −h 7 ≧x(h 0 −h 6′ ). If P 2 and temperature differences between T 8 and T 8′ and T 6 and T 6′ are given, h 8′ , h 7 , h 0 , h 6′ can be determined and x can then be expressed by:
[0000]
x
≤
(
h
8
′
-
h
7
)
(
h
0
-
h
6
′
)
.
[0000] According to the second law of thermodynamics, the relationship for the exergy is: Ex 7-8′ ≦xEx 0-6′ ,
[0000]
x
≤
Ex
7
-
8
′
Ex
0
-
6
′
.
If
[0134]
x
=
(
h
8
′
-
h
7
)
(
h
0
-
h
6
′
)
,
[0000] the above relation
[0000]
x
≤
Ex
7
-
8
′
Ex
0
-
6
′
[0000] always holds. That implies that vaporization of 1 unit of working fluid can pre-cool
[0000]
x
=
(
h
g
′
-
h
7
)
(
h
0
-
h
6
′
)
[0000] unit of input air. If the efficiency of heat exchanger is high enough, then x could be greater than 1. The specific cold recycled in this practical recycle is: Q 7-8′ =xQ 0-6′ =x(h 0 −h 6′ ). As mentioned above, the cold energy in liquid air is very high-grade energy, assuming the air is an ideal gas, the above cold energy is equivalent to the ideal work given by: W 7-8′ =x[T 0 (S 0 −S 6′ )−(h 0 −h 6′ )]. The specific net work output of the cycle is therefore given by:
[0000]
W
net
=
W
8
′
-
0
′
-
W
5
-
7
+
W
7
-
8
′
=
T
0
′
(
S
0
′
-
S
8
′
)
-
(
h
0
′
-
h
8
′
)
-
(
h
7
-
h
5
)
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
[0000] and the energy density of CES is:
[0000]
E
D
=
W
net
1
=
T
0
′
(
S
0
′
-
S
8
′
)
-
(
h
0
′
-
h
8
′
)
-
(
h
7
-
h
5
)
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
.
[0000] The energy efficiency of the whole energy storage system (air liquefaction+CES) E E can be calculated by:
[0000]
E
E
=
E
D
E
C
.
[0000] Considering the efficiency of pump η P , the efficiency of turbine η T and the efficiency of air liquefaction η A , the net work W net should be:
[0000]
W
net
′
=
η
T
W
8
-
0
-
1
η
P
W
5
-
7
+
W
0
-
6
′
=
η
T
[
T
0
′
(
S
0
′
-
S
8
′
)
-
(
h
0
′
-
h
8
′
)
]
-
(
h
7
-
h
5
)
η
P
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
[0000] The energy density of CES E D becomes:
[0000]
E
D
′
=
W
net
′
1
=
η
T
[
T
0
′
(
S
0
′
-
S
8
′
)
-
(
h
0
′
-
h
8
′
)
]
-
(
h
7
-
h
5
)
η
P
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
[0000] and the energy efficiency of the whole energy storage system becomes:
[0000]
E
E
′
=
E
D
′
E
C
.
[0000] Considering further the use of waste heat, if T 0 is superheated to T 9 using the waste heat from the power plant, as shown in FIG. 7 , the specific net work output of the cycle will be:
[0000]
W
net
2
=
W
9
-
10
-
W
5
-
7
+
W
7
-
8
′
=
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
-
(
h
7
-
h
5
)
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
[0000] and the energy density of CRS is:
[0000]
E
D
2
=
W
net
2
1
=
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
-
(
h
7
-
h
5
)
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
.
[0000] This leads to the following energy efficiency of the entire energy storage system (air liquefaction system+CES) E E2 :
[0000]
E
E
2
=
E
D
2
E
C
.
[0000] If T 0 =300K and neglecting the energy losses due to the turbine, pump and heat exchangers, the ideal work output for a unit mass of liquid air can be estimated on the basis of the above analysis by:
[0000]
W
net
=
W
8
′
-
0
′
-
W
5
-
7
+
W
7
-
8
′
=
T
0
′
(
S
0
′
-
S
8
′
)
-
(
h
0
′
-
h
8
′
)
-
(
h
7
-
h
5
)
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
=
743
kJ
/
kg
[0000] and the ideal energy density of CES is:
[0000]
E
D
=
W
net
1
=
T
0
′
(
S
0
′
-
S
8
′
)
-
(
h
0
′
-
h
8
′
)
-
(
h
7
-
h
5
)
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
.
=
180.8
kWh
/
m
3
[0000] If E C =1440 kJ/kg (0.4 kWh/kg), the ideal energy efficiency of CES is:
[0000]
E
E
=
E
D
E
C
=
51.6
%
[0000] If E C =1080 kJ/kg (0.3 kWh/kg), the ideal energy efficiency of CES becomes:
[0000]
E
E
=
E
D
E
C
=
68.8
%
[0000] If T 9 is superheated to 400K using the waste heat from the power plant, the specific ideal work is:
[0000]
W
net
2
=
W
9
-
10
-
W
5
-
7
+
W
7
-
8
′
=
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
-
(
h
7
-
h
5
)
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
.
=
881
kJ
/
kg
[0000] The ideal energy density of CES is:
[0000]
E
D
2
=
W
net
2
1
=
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
-
(
h
7
-
h
5
)
+
x
[
T
0
(
S
0
-
S
6
′
)
-
(
h
0
-
h
6
′
)
]
]
.
=
214.3
kWh
/
m
3
[0000] If E C =1440 kJ/kg (0.4 kWh/kg), the ideal energy efficiency of CES is:
[0000]
E
E
=
E
D
E
C
=
61.2
%
.
[0000] If E C =1080 kJ/kg (0.3 kWh/kg), the ideal energy efficiency of CES becomes:
[0000]
E
E
=
E
D
E
C
=
81.6
%
.
[0000] Note that the energy consumption (0.3 and 0.4 kWh/kg) used above is for separation of oxygen from air. The actual energy requirement of liquid air production is approximately 80% of this figure so the estimation of the ideal energy efficiency is conservative. On the other hand, the probable actual efficiency is approximately 80% of that achieved in the ideal work cycle so the efficiency as estimated above should be close to the actual efficiency.
[0135] From the above analyses, it can be concluded that the work output of CES increases significantly for a given amount of cryogenic fuel consumption owing to the recovery of the cold energy. The extra work from cold recycle is equivalent to x[T 0 (S 0 −S 6′ )−(h 0 −h 6′ )] where x is determined by the temperature difference and energy losses of components. The specific work output and energy density of CES depends on the efficiency of the turbine η T and the energy consumption per unit mass of liquid air in the air liquefaction plant E C . The efficiency of the pump is also a factor but not as important as η T and E C because the work consumed by a pump is relatively small. An increase in the temperature differences of heat exchangers will increase the liquid air consumption or decrease the efficiency of the cycle. It can be seen that the energy efficiency and energy density of the energy storage system E E is competitive to other currently available energy systems. The system of the present invention also offers the advantages of producing other products from the air liquefaction plant and using the waste heat from the power plant.
Low Input Air Pressure Case—Thermodynamics Cycle of CES Analysis
[0136] The thermodynamics cycle of a CES for a low input air pressure case is shown in FIG. 8 . Here, the term ‘low pressure’ denotes pressures lower than ˜3.8 MPa below which air vaporisation is approximately isothermal. The cycle consists of the following processes similar to those described above:
[0000] 1) Process 0-2, Isothermal pressurization of input air: The input air is compressed isothermally from the ambient pressure P 0 to P 1 . The work done on the air by the compressor is: W 0-2 =T 0 (S 0 −S 2 )−(h 0 −h 2 ). The heat Q 0-2 of this isothermal process is: Q 0-2 =T 0 (S 0 −S 2 ). Unfortunately, it is difficult to realize an absolute isothermal pressurization process, the actual process will be a polytropic process like 0-1.
2) Process 2-3′-3, Extraction of cold energy from the working fluid by input air: The compressed input air is used to extract the cold energy from the working fluid isobarically. The work done in this process is zero: W 2-3 =0. The heat released from the input air in the process 2-3 is: Q 2-3′ =h 3′ −h 2 . The heat released from input air in the process 3-3′ is: Q 3′-3 =h 3′ −h 3 =T 3 (S 3′ −S 3 )=λ. The exergy obtained from the process is therefore given by: Ex 2-3 =T 0 (S 3 −S 2 )−(h 3 −h 2 ).
3) Process 3-4-5(-6), Throttling of compressed input air: The compressed input air is throttled to the ambient pressure for condensation. The work done in this process is zero: W 3-4 =0. The heat released from the input air is zero: Q 3-4 =0. Considering one unit of the working fluid, the total amount of input air is x units of which a fraction y is liquefied, the amount of liquefied air at state 5 will be xy, and the amount of gaseous air at state 6 will be x(1−y). A heat balance over the process 3-4-5(-6) will be: h 3 =yh 5 +(1−y)h 6 .
4) Process 5-7, Pumping process of working air: Process 5-7 in FIG. 8 is the same as that in FIG. 5 in which liquid air from the cryogen tank is pumped from the ambient pressure P 0 to P 2 . The specific work done on the liquid air is:
[0000]
W
5
-
7
=
V
I
(
P
2
-
P
0
)
=
(
P
2
-
P
0
)
ρ
I
.
[0000] The above work can also be expressed by the enthalpy difference between state 7 and state 5: W 5-7 =h 7 −h 5 .
5) Process 7-7′, Isobaric heating of the working fluid to condense input air: The working fluid is heated to condense the input air at T 3 . The specific work done in this process is zero: W 7-7′ =0. The specific heat absorbed from the input air is: Q 7-7′ =h 7′ −h 7 .
6) Process 7′-8, Isobaric heating of the working fluid to cool the input air: The working fluid is heated by the input air from T 7′ to T 8 . The specific work done in this process is zero: Q 7′-8 =0. The specific heat absorbed from the input air is: Q 7′-8 =h 8 −h 7′ . The exergy released in the process 7-8 is: W 7-8 =T 0 (S 8 −S 7 )−(h 8 −h 7 ).
7) Process 8-9, Isobaric superheating of the working fluid: The working fluid is superheated by from T 8 to T 9 in which no work is done, i.e.: W 8-9 =0 while the specific heat absorbed from the input air over this process is: Q 8-9 =h 9 −h 8 .
8) Process 9-10, Isothermal expansion of the working fluid: The working fluid with a high pressure expands in the turbine isothermally which delivers work to generate electricity. The specific ideal work done in this process is: W 9-10 =T 9 (S 10 −S 9 )−(h 10 −h 9 ). The specific heat absorbed by the working fluid from the ambient in the process is: Q 9-10 =T 9 (S 10 −S 9 ). It should be noted that the T 9 is higher than the ambient temperature, which requires energy from the waste heat from the power plant to ensure an isothermal expansion. If the expansion of air is an adiabatic process, the specific ideal work W ad will be:
[0000]
W
ad
=
k
k
-
1
RT
9
[
P
0
P
2
)
(
k
-
1
)
k
-
1
]
.
[0000] which means no heat absorption namely: Q ad =0. The actual work, however, is expected to be in the range between W 9-10 and W ad . A factor called isothermicity γ is often used as an index, which is defined as the ratio of the actual work to the isothermal work:
[0000]
γ
=
W
ac
W
9
-
10
.
[0000] Thus, the actual work W ac can expressed as:
[0000]
W
ac
=
γ
W
9
-
10
=
γ
RT
9
ln
(
P
2
P
0
)
.
[0000] 9) Process 6-6′, Extraction of cold from exhaust air to condense the input air: The exhaust air (part of input air after the throttling) is used to condense the input air isobarically. The specific work done in this process is zero: W 6-6′ =0. The specific heat absorbed from input air is: Q 6-6′ =h 6′ −h 6 . The heat balance of 3′-3, 7-7′ and 6-6′ is therefore given by: xQ 3-3′ =Q 7-7′ +x(1−y)Q 6-6′ , x(h 3 −h 3′ )=(h 7′ −h 7 )+x(1−y)(h 6′ −h 6 ).
10) Process 6′-0, Extraction of cold from exhaust air to cool the input air: The exhaust air is used to cool down the input air isobarically. The specific work done in this process is zero: W 6′-0 =0. The specific cold absorbed from the exhaust air by the input air is: Q 6′-0 =h 0 −h 6′ . The heat balance of 2-3′, 7′-8 and 6′-0 is expressed as: xQ 2-3′ ≦Q 7′-8 +x(1−y)Q 6′-0 , x(h 2 −h 3′ )≦(h 8 −h 7′ )+x(1−y)(h 0 −h 6′ ). The exergy obtained in process 6-0 is: Ex 0-6 =T 0 (S 0 −S 6 )−(h 0 −h 6 ). From the heat and exergy balances of the cycle, x and y can be calculated by the following equations based on the T-S diagram in FIG. 8 ):
[0000]
{
h
3
=
yh
5
+
(
1
-
y
)
h
6
x
(
h
3
-
h
3
′
)
=
(
h
T
′
-
h
7
)
+
x
(
1
-
y
)
(
h
6
′
-
h
6
)
x
(
h
2
-
h
3
′
)
≤
(
h
8
-
h
7
′
)
+
x
(
1
-
y
)
(
h
0
-
h
6
′
)
xEx
2
-
3
≤
Ex
7
-
8
+
x
(
1
-
y
)
Ex
0
-
6
.
[0000] From the above equations, the ratio of liquefaction of the input air y is:
[0000]
y
=
(
h
6
-
h
4
)
(
h
6
-
h
5
)
.
[0000] Because (h 6 −h 5 )>(h 6 −h 4 )>0 always holds, therefore 1>y>0. Similarly, x can be expressed as:
[0000]
x
=
(
h
7
′
-
h
7
)
(
h
3
-
h
3
′
)
-
(
1
-
y
)
(
h
6
′
-
h
6
)
.
[0000] As (h 7′ −h 7 )>0, [(h 3 −h 3′ )−(1−y)(h 6′ −h 6 )]>0 always holds, x>0. This means that vaporisation of one unit of the working fluid can produce xy units of liquid air, and the consumption of the cycle will be (1−xy). As a consequence, the specific net work output of the cycle is:
[0000]
W
net
=
W
9
-
10
-
W
5
-
7
-
xW
0
-
2
=
[
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
]
-
(
h
7
-
h
5
)
-
x
(
T
0
(
S
0
-
S
2
)
)
[0000] and the energy density of CES can be expressed by:
[0000]
E
D
=
W
net
1
-
xy
=
[
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
]
-
(
h
7
-
h
5
)
-
x
(
T
0
(
S
0
-
S
2
)
)
1
-
xy
.
[0000] The energy efficiency of the entire energy storage system (Air liquefaction system+CES) E E can therefore be calculated by:
[0000]
E
E
=
E
D
E
C
.
[0000] Considering the efficiencies of the pump η P , the turbine η T and the compressor η COM , the net work W net should be:
[0000]
W
net
′
=
η
T
W
9
-
10
-
W
5
-
7
η
P
-
W
0
-
2
η
COM
=
η
T
[
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
]
-
(
h
7
-
h
5
)
η
P
-
x
(
T
0
(
S
0
-
S
2
)
)
η
COM
,
[0000] the energy density of CES E D becomes:
[0000]
E
D
′
=
W
net
′
1
-
xy
=
η
T
[
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
]
-
(
h
7
-
h
5
)
η
P
-
x
(
T
0
(
S
0
-
S
2
)
)
η
COM
1
-
xy
[0000] and E E becomes:
[0000]
E
E
=
E
D
′
E
C
.
[0137] Based on the above analysis, it can be concluded that, in comparison with cryogenic (liquid nitrogen) powered engines, the consumption of cryogenic fuel is reduced by xy for 1 unit of working fluid but with a penalty of work required for compression W 0-2 =T 0 (S 0 −S 2 ). The specific work output will be improved as the penalty is less than the benefit due to the reduction in the working fluid consumption. As the work of compression is much less than the work output of the turbine, the specific work output and the energy density of CES mainly depend on the efficiency of the turbine η T and energy consumption for air liquefaction. This is similar to the case of using the ambient pressure. The efficiencies of pump and compressor are not key factors for improving the work output and energy density of CES. The efficiency of this cycle is expected to be lower than that of FIG. 6 because the process of isothermal condensation has low energy efficiency.
High Input Air Pressure Case—Thermodynamics Cycle of CES Analysis
[0138] The thermodynamic cycle of the CES for a high input air pressure case is shown in FIG. 9 . Here, the term ‘high input air pressure’ means the pressure is higher than 3.8 MPa above which air has no isothermal vaporisation process. The processes of this case are as follows:
[0000] 1) Process 0-2, Isothermal pressurization of input air: The input air is compressed from ambient pressure P 0 to P 1 isothermally. The work done on the air by the compressor is: W 0-2 =T 0 (S 0 −S 2 )−(h 0 −h 2 ). The heat Q 0-2 of this isothermal process is: Q 0-2 =T 0 (S 0 −S 2 ). Unfortunately, it is difficult to realize an absolute isothermal pressurisation process, the actual process will be 0-1.
2) Process 2-3, Extraction of cold energy from the working air by input air: The compressed input air is used to extract the cold energy from the work fluid isobarically. The work done in this process is zero: W 2-3 =0. The heat released from the input air for process 2-3 is: Q 2-3 =h 3 −h 2 . The exergy obtained from the process is: Ex 2-3 =T 0 (S 3 −S 2 )−(h 3 −h 2 ).
3) Process 3-4-5(-6), Throttling of compressed input air: The compressed input air is throttled to the ambient pressure for condensation. The work done in this process is zero: W 3-4 =0. The heat released from the input air is zero: Q 3-4 =0. Similar to the low input air pressure case, considering one unit of working fluid and assuming a total of x units of input air of which a fraction y is liquefied, the amount of liquid air produced by liquefaction at state 5 is xy, and the amount of gaseous air at state 6 is x(1−y). The heat balance of 3-4-5(6) is therefore expressed as: h 3 =yh 5 +(1−y)h 6 .
4) Process 5-7, Pumping of working fluid: This process is the same as that in FIG. 6 . Liquid air from the cryogen tank is pumped from ambient pressure P 0 to P 2 . The work done on a unit mass of liquid air is:
[0000]
W
5
-
7
=
V
l
(
P
2
-
P
0
)
=
(
P
2
-
P
0
)
ρ
l
.
[0000] The work can also be expressed by enthalpy difference between the states 7 and 5: W 5-7 =h 7 −h 5 .
5) Process 7-8, Isobaric beating of the working fluid to cool input air: The working fluid is heated to condense the input air at T 3 , and there is work involved in this process: W 7-8 =0. The specific heat absorbed from the input air is: Q 7-8 =h 8 −h 7 . The exergy released in the process 7-8 is therefore: W 7-8 =T 0 (S 8 −S 7 )−(h 8 −h 7 ).
6) Process 8-9, Isobaric superheating of the working fluid: The working fluid is superheated by the input air from T 8 to T 9 in which zero work is done, i.e. W 8-9 =0. The specific heat absorbed from input air is: Q 8-9 =h 9 −h 8 .
7) Process 9-10: Isothermal expansion of the working fluid: The working fluid with a high pressure expands in the turbine and delivers work isothermally. The specific ideal work done in this process is: W 9-10 =T 9 (S 10 −S 9 )−(h 10 −h 9 ) while the specific heat absorbed in the process is: Q 9-10 =T 9 (S 10 −S 9 ). Similar to the low pressure case, T 9 is higher than the ambient temperature; the waste heat from the power plant is needed to keep this process isothermal. If the expansion of the working fluid is adiabatic, the specific ideal work W ad will be:
[0000]
W
ad
=
k
k
-
1
RT
9
[
P
0
P
2
)
(
k
-
1
)
k
-
1
]
.
[0000] The specific heat absorbed in the process is: Q ad =0. As a result of the above analysis, the actual work should be in the range between W 9-10 and W ad . As mentioned before, the isothermicity γ is used to describe the non-ideality:
[0000]
γ
=
W
ac
W
9
-
10
.
[0000] Thus, the actual work W ac should be expressed as: W ac =γW 9-10 =γ[T 9 (S 10 −S 9 )−(h 10 −h 9 )].
8) Process 6-0, Extraction of cold energy from the exhaust air to cool the input air: The exhaust air after the throttling is used to cool the input air isobarically. The specific work done in this process is zero: W 6-0 =0. The specific cold absorbed by the input air is: Q 6-0 =h 0 −h 6 . The heat balance over processes 2-3, 7-8 and 6-0 is expressed as: xQ 2-3 =Q 7-8 +x(1−y)Q 6-0 , x(h 2 −h 3 =(h 8 −h 7 )+x(1−y)(h 0 −h 6 ). The exergy obtained in the process 6-0 is: Ex 0 -6=T 0 (S 0 −S 6 )−(h 0 −h 6 ). Based on the heat and exergy balances of processes 2-3, 3-4-5-6, 7-8, 6-0, x and y can be calculated by the following equations on the basis of a T-S diagram for the air:
[0000]
{
h
3
=
yh
5
+
(
1
-
y
)
h
6
x
(
h
2
-
h
3
)
=
(
h
8
-
h
7
)
+
x
(
1
-
y
)
(
h
0
-
h
6
)
xEx
2
-
3
≤
Ex
7
-
8
+
x
(
1
-
y
)
Ex
0
-
6
.
[0000] From the above equations, the ratio of liquefaction of the input airy can be expressed by:
[0000]
y
=
(
h
6
-
h
4
)
(
h
6
-
h
5
)
.
[0000] Similar to the method in the low pressure case, 1>y>0 always holds, and x can be expressed as:
[0000]
x
=
(
h
8
-
h
7
)
(
h
2
-
h
3
)
-
(
1
-
y
)
(
h
0
-
h
6
)
.
[0000] As (h 8 −h 7 )>0, [(h 2 −h 3 )−(1−y)(h 0 −h 6 )]>0 always holds, one has x>0. This means vaporisation of one unit of working fluid could produce xy units of liquid air, while the consumption of this cycle is 1−xy, and the specific net work output of the cycle will be:
[0000]
W
net
=
W
9
-
10
-
W
5
-
7
-
xW
0
-
2
=
[
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
]
-
(
h
7
-
h
5
)
-
x
(
T
0
(
S
0
-
S
2
)
)
[0000] and the energy density of CES is:
[0000]
E
D
=
W
net
1
-
xy
=
[
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
]
-
(
h
7
-
h
5
)
-
x
(
T
0
(
S
0
-
S
2
)
1
-
xy
.
[0000] The energy efficiency of the entire energy storage system (Air liquefaction+CES) E E can therefore be calculated by:
[0000]
E
E
=
E
D
E
C
.
[0000] Considering the efficiencies of the pump η P , the turbine in η T and the compressor η COM , one has the following net work W net :
[0000]
W
net
′
=
η
T
W
9
-
10
-
W
5
-
7
η
P
-
W
0
-
2
η
COM
=
η
T
[
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
]
-
(
h
7
-
h
5
)
η
P
-
x
(
T
0
(
S
0
-
S
2
)
η
COM
.
[0000] As a result of the above, the energy density of CES E D becomes:
[0000]
E
D
′
=
W
net
′
1
-
xy
=
η
T
[
T
9
(
S
10
-
S
9
)
-
(
h
10
-
h
9
)
]
-
(
h
7
-
h
5
)
η
P
-
x
(
T
0
(
S
0
-
S
2
)
η
COM
1
-
xy
[0000] and E E becomes:
[0000]
E
E
=
E
D
′
E
C
.
[0000] From the above analysis, it can be seen that, compared with the design of liquid nitrogen powered engines, the consumption of cryogenic fuel for this cycle is decreased by xy but with a penalty of work by W 0-2 =T 0 (S 0 −S 2 )−(h 0 −h 2 ). However, the specific work output is improved due to the decrease of liquid fuel consumption. The work required by the compressor should be comparable with that produced by the turbine. As a consequence, the efficiency of the compressor η COM becomes a key parameter determining the overall efficiency of the CES. This cycle is more suitable for producing liquid air through the CES part of the energy storage system.
[0139] The above thermodynamics analyses on the four typical cycles show that:
1) The energy efficiency and energy density of CES are improved in comparison with liquid nitrogen powered engines owing to the cold energy recycle. 2) The overall performance of the energy storage system is determined by the efficiency of the turbine, and the specific work output and the specific energy consumption of the air liquefaction plant. 3) The temperature differences across the heat exchangers will increase the liquid air consumption thus decreasing the efficiency of the cycle. 4) The energy efficiency and density of the CES will be improved if the waste heat from the power plant is utilised.
[0144] The results also show that the efficiency of the CES is competitive to other energy storage systems. Additionally, the system can make use of the waste heat and produce air products if needed.
Thermodynamics Cycle Analysis—CPS
[0145] FIG. 10 a shows thermodynamic cycles for a CPS according to the present invention. There are four air steams which are denoted by the following lines: working fluid—line 580 ; input air 1 —line 585 ; input air 2 —line 590 ; and input air 3 —line 595 . In the analyses, liquid air is treated as a single phase fluid and the gaseous air as an ideal gas. The energy losses in the compressor 520 , turbine 510 , and pump 555 are accounted for by using their efficiencies η. For these thermodynamic analyses, the frictional and regional losses due to flow in pipes, valves and bends are ignored and dissipation of cryogen during storage are not considered. The ambient temperature and pressure are expressed by T 0 and P 0 , respectively; the boiling temperature of liquid air is denoted as T S .
[0000] 1) 1-2: Pumping process of working fluid: The working fluid (liquid air) from the cryogen tank is pumped from the ambient pressure P 0 to P 2 . The specific work done on the liquid air is:
[0000]
W
1
-
2
=
V
l
(
P
2
-
P
0
)
=
(
P
2
-
P
0
)
ρ
l
.
[0000] The above work can also be expressed by the enthalpy difference between state 2 and state 1: W 1-2 =h 2 −h 1 .
2) 2-2′: Isobaric heating of working fluid to condense input air 1 : The working fluid is heated to condense the input air at T 7 . The specific work done in this process is zero: W 2-2′ =0. The specific heat absorbed from the input air 1 is: Q 2-2′ =h 2′ −h 2 .
3) 2′-3: Isobaric heating of working fluid: The working fluid is heated by the input air from T 2′ to T 3 . The specific work done in this process is zero: W 2′-3 =0. The specific heat absorbed from the input air is: Q 2′-3 =h 3 −h 2′ . The exergy released in the process 2-3 is: Ex 2-3 =T 0 (S 3 −S 2 )−(h 3 −h 2 ).
4) 3-0: Isothermal expansion of working fluid: The working fluid with a high pressure expands in the turbine isothermally which delivers work to generate propulsion and electricity. The specific ideal work done in this process is: W 3-0 =T 0 (S 0 −S 3 )−(h 0 −h 3 ). The specific heat absorbed from the ambient in the process is: Q 3-0 =T 0 (S 0 −S 3 ). If the expansion of the working fluid is adiabatic, the specific ideal work W ad will be:
[0000]
W
ad
=
k
k
-
1
RT
0
[
P
0
P
2
)
(
k
-
1
)
k
-
1
]
[0000] which means no heat absorption, namely: Q ad =0. The actual work, however, is expected to be in the range between W 3-0 and W ad . A factor called isothermicity, γ, is often used as an index, which is defined as the ratio of the actual work to the isothermal work:
[0000]
γ
=
W
ac
W
3
-
0
.
[0000] Thus, the actual work W ac can be expressed as: W ac =γW 3-0 =γ[T 0 (S 0 −S 3 )−(h 0 −h 3 )].
5) 0-4: Polytropic pressurisation of input air 1 : The input air 1 is compressed polytropically from the ambient pressure P 0 to P 1 . The work done on the air by the compressor is:
[0000]
W
0
-
4
=
n
n
-
1
RT
0
[
(
P
1
P
0
)
(
n
-
1
)
n
-
1
]
[0000] where n is the polytropic coefficient. The heat, Q 0-4 , of this polytropic process is: Q 0-4 =c n (T 4 −T 0 ) where C n is the polytropic heat ratio:
[0000]
c
n
=
n
-
k
n
-
1
C
V
.
[0000] T 4 can be calculated by:
[0000]
T
4
T
0
=
(
P
1
P
0
)
n
-
1
n
.
[0000] 6) 4-5: Release of heat from input air 1 isobarically to input air 2 : The heat of the input air 1 is released to the input air 2 or water to produce hot air/water. The work done in this process is zero: W 4-5 =0. The heat released from the input air 1 in the process 4-5 is: Q 4-5 =h 4 −h 5 .
7) 5-6-7: Cooling of input air 1 by working fluid: The compressed input air 1 is cooled by working fluid isobarically and the cold energy inside the working fluid is extracted at the same time. The work done in this process is zero: W 5-7 =0. The heat released from the input air 1 in the process 5-6 is: Q 5-6 =h 5 −h 6 . The heat released from input air in the process 6-7 is: Q 6-7 =h 6 −h 7 =T 6 (S 6 −S 7 )=. The exergy obtained from the process is therefore given by: EX 5-6-7 =T 0 (S 5 −S 7 )−(h 5 −h 7 ).
8) 7-8-9(-1): Throttling of compressed input air 1 : The compressed input air 1 is throttled to the ambient pressure for condensation. The work done in this process is zero: W 7-8 =0. The heat released from the input air is zero: Q 7-8 =0.
9) 9-9′: Extraction of cold from exhaust air to condense the input air: The exhaust air (part of input air 1 after the throttling) is used to condense the input air isobarically. The specific work done in this process is zero: W 9-9′ =0. The specific heat absorbed from input air is: Q 9-9′ =h 9′ −h 9 .
10) 9′-0: Extraction of cold from exhaust air to cool the input air: The exhaust air (part of the input air 1 ) is used to cool down the input air 1 isobarically. The specific work done in this process is zero: W 9′-0 =0. The specific cold absorbed from the exhaust air by the input air 1 is: Q 9′-0 =h 0 −h 9′ . The exergy obtained in process 9-0 is: EX 9-0 =T 0 (S 0 −S 9 )−(h 0 −h 9 ).
11) 0-10: Extraction of cold energy of the working fluid by input air 3 isobarically for air conditioning: The cold of the working fluid is extracted by input air 3 for cool air production to be used for air conditioning. The work done in this process is zero: W 0-10 =0. The cold energy from the working fluid in the process 0-10 is: Q 0-10 =h 0 −h 10 .
12) 0-10-11: Extraction of cold energy of the working fluid by input air 4 isobarically for refrigeration: The cold of the working fluid is extracted by input air 4 for refrigeration. The work done in this process is zero: W 0-11 =0. The cold energy from the working fluid in the process 0-11 is: Q 0-11 =h 0 −h 11 .
13) 0-12: Extraction of heat energy of the input air 1 by input air 2 /water isobarically: The heat of the input air 1 is extracted by input air 2 /water for hot air/water production. The work done in this process is zero: W 0-12 =0. The heat released from the input air 1 in the process 0-12 is: Q 0-12 =h 12 −h 0 .
Analysis of Energy Balance
[0146] Assuming that, for one unit of the working fluid, the total amount of input air 1 is x 1 , the total amount of input air 2 is x 2 , the total amount of input air 3 / 4 is x 3 +x 4 with x 3 units for air condition and x 4 units for refrigeration. In the one unit of the working fluid, a 1 units are used for the input air 1 , a 2 +a 3 units for cooling input air 3 / 4 in which a 2 is for x 3 and a 3 is for x 4 . According to the first and second laws of thermodynamics, the following balances of heat and exergy can be obtained:
[0000] 1) Heat balance in process 7-8-9(-1): Assuming that, for a 1 units of the working fluid, y fraction of the input air 1 is liquefied, the amount of liquefied air at State 1 will be x 1 y, and the amount of gaseous air at State 9 will be x 1 (1−y). A heat balance over the process 7-8-9(-1) will be: h 7 =yh 1 +(1−y)h 9 . From the above equations, ratio of liquefaction of the input air y is:
[0000]
y
=
(
h
9
-
h
7
)
(
h
9
-
h
1
)
.
[0000] Because (h 9 −h 1 )>(h 9 −h 7 )>0 always holds, therefore 1>y>0.
2) Heat balance in processes 6-7, 2-2′ and 9-9′: The heat balance of 6-7, 2-2′ and 9-9′ x 1 (h 6 −h 7 )=a 1 (h 2′ −h 2 )+x 1 (1−y)(h 9′ −h 9 ). x 1 can be expressed as:
[0000]
x
1
=
a
1
(
h
2
′
-
h
2
)
(
h
6
-
h
7
)
-
(
1
-
y
)
(
h
9
′
-
h
9
)
.
[0000] 3) Heat balance in processes 5-6, 2′-3 and 9′-0: The heat balance of 5-6, 2′-3 and 9′-0 can is expressed as: x 1 Q 5-6 ≦a 1 Q 2-3 +x 1 (1−y)Q 9′-0 , x 1 (h 5 −h 6 )≦a 1 (h 3 −h 2 )+x 1 (1−y)(h 0 −h 9′ ).
4) Heat balance in processes 4-5 and 0-12: The heat balance in processes 4-5 and 0-12 can be expressed by: x 2 (h 12 −h 0 )=x 1 (h 5 −h 4 ). x 2 can be expressed as:
[0000]
x
2
=
x
1
(
h
5
-
h
4
)
(
h
12
-
h
0
)
.
[0000] 5) Heat balance in processes 0-10 and 2-3: The heat balance in processes 0-10 and 2-3 can be expressed by: x 3 (h 0 −h 10 )=a 2 (h 3 −h 2 ). x 3 can be expressed as:
[0000]
x
3
=
a
2
(
h
3
-
h
2
)
(
h
0
-
h
10
)
.
[0000] 6) Heat balance in processes 0-11 and 2-3: The heat balance in processes 0-11 and 2-3 can be expressed by: x 4 (h 0 −h 11 )=a 3 (h 3 −h 2 ). x 4 can be expressed as: x 4 =a 3 (h 3 −h 2 )/(h 0 −h 11 ).
7) Exergy balance of processes 5-7, 2-3 and 9-0: The exergy balance of processes 5-7, 2-3 and 9-0 can be given by: x 1 Ex 5-7 ≦a 1 Ex 2-3 +x 1 (1−y)Ex 0-9 , x 1 [T 0 (S 5 −S 7 )−(h 5 −h 7 )]≦a 1 [T 0 (S 3 −S 2 )−(h 3 −h 2 )]+x 1 [T 0 (S 0 −S 9 )−(h 0 −h 9 )].
8) Mass conservation of process 2-3:
[0000] a 1 +a 2 +a 3 =1
Analysis of the Efficiency and Energy Density
[0147] The following analyses use the efficiency of work (electricity) defined as:
[0000]
η
w
=
W
output
W
input
[0000] where W output and W input are the total works converted by the input and output energies, respectively. To calculate the equivalent work of heat and cold energy, two coefficients of performance (COP), refrigeration COP (ε), and heat pump COP (ζ), are used in the conversion of heat to work. As a consequence, the specific net work output of the cycle
[0000]
W
output
=
W
3
-
0
-
W
1
-
2
-
x
1
W
0
-
4
+
1
ζ
x
2
Q
0
-
12
+
1
ɛ
1
x
3
Q
0
-
10
+
1
ɛ
2
x
4
Q
0
-
11
is
:
=
[
T
0
(
S
0
-
S
3
)
-
(
h
0
-
h
3
)
]
-
(
h
2
-
h
1
)
-
x
1
n
n
-
1
RT
0
[
P
0
P
1
)
(
n
-
1
)
n
-
1
]
+
1
ζ
x
2
(
h
12
-
h
0
)
+
1
ɛ
1
x
3
(
h
0
-
h
10
)
+
1
ɛ
x
4
(
h
0
-
h
11
)
.
[0000] On the other hand, the productivity of liquid air by input air 1 is x 1 y. Therefore the consumption of the working fluid is (1−x 1 y). The energy density of CPS can be expressed by:
[0000]
E
D
=
W
output
1
-
x
1
y
.
[0000] It is known that the maximum specific work of liquid air, W R , is: W R =T 0 (S 0 −S 1 )−(h 0 −h 1 ). The energy efficiency of the CPS, E E , can therefore be calculated by:
[0000]
E
E
=
W
output
(
1
-
x
1
y
)
W
R
.
[0000] Considering the efficiencies of the pump η P , the turbine η T and the compressor η COM , the net work W output should be:
[0000]
W
output
′
=
η
T
W
3
-
0
-
W
1
-
2
η
P
-
x
1
W
0
-
4
η
COM
+
1
ζ
x
2
Q
0
-
12
+
1
ɛ
1
x
3
Q
0
-
10
+
1
ɛ
2
x
4
Q
0
-
11
=
1
η
T
[
T
0
(
S
0
-
S
3
)
-
(
h
0
-
h
3
)
]
-
1
η
F
(
h
2
-
h
1
)
-
x
1
η
COM
n
n
-
1
RT
0
[
P
0
P
1
)
(
n
-
1
)
n
-
1
]
+
1
ζ
x
2
(
h
12
-
h
0
)
+
1
ɛ
1
x
3
(
h
0
-
h
10
)
+
1
ɛ
x
4
(
h
0
-
h
11
)
,
[0000] the energy density of CPS, E D , becomes:
[0000]
E
D
′
=
W
net
′
1
-
x
1
y
[0000] and E E becomes:
[0000]
E
E
′
=
W
output
′
(
1
-
x
1
y
)
W
R
.
[0000] Based on the above analysis, it can be concluded that:
1) The maximum specific work W R gives the upper limit of the energy density of CPS. If ambient temperature T 0 =300 K is used, the value is ˜743 kJ/kg. 2) If there is no cold energy recycling, the ideal specific work output will be W output =W 3-0 −W 1-2 . The practical value
[0000]
W
output
′
=
η
T
W
3
-
0
-
W
1
-
2
η
P
[0000] gives the lower limit of the CPS. If ambient temperature T 0 =300K (is used and the working pressure of liquid air is 200 bar, assuming the efficiencies turbine and pump are both 0.78, the specific work output would be ˜326 kJ/kg.
[0150] If the pressure of the input air 1 exceeds ˜38 bar, there will be no isothermal condensing process in FIG. 10 a . The T-S diagram of this case is shown in FIG. 10 b . The thermodynamic analysis is similar to the case in FIG. 10 a.
Parametric Analysis—CES
[0151] A computational code has been written in the Fortran 90 environment to simulate the influences of various parameters on the performance of the CES system. The code is written for thermodynamics cycles operated between pressures above the ambient pressure and 3.8 MPa (see FIG. 8 ), which is the most complicated case. The code can be used easily for high pressure cases (see FIG. 9 ) and the ambient condition (see FIGS. 5 to 7 ). Six parameters have been considered including:
Pressure of the working fluid (P 2 ), Pressure of the input air (P 1 ), Efficiency of the turbine (η T ), Efficiency of the compressor (η COM ), Efficiency of the pump (η P ), Efficiency of the air liquefaction plant (η A ).
[0158] The effects of these six parameters on four efficiencies related to the performance of the CES have been analysed. The four efficiencies that have been considered are:
the efficiency of the ideal cycle without superheating (E E ), efficiency of the ideal cycle with superheating (E Sup ), efficiency of the practical cycle without superheating (E′ E ) efficiency of the practical cycle with superheating (E′ Sup ).
Pressure of the Working Fluid (P 2 )
[0163] The four efficiencies of the thermodynamics cycles associated with the CES are shown in FIGS. 11 to 18 under nine different pressures of the working fluid (P 2 =0.2 MPa, 0.4 MPa, 1.0 MPa, 2.0 MPa, 4.0 MPa, 10 MPa, 20 MPa, 30 MPa, 40 MPa and 50 MPa) at different input air pressures (P 1 ). The ambient temperature is assumed to be T 0 =300K, the superheat temperature is taken as T 9 =400K, and the efficiencies of the turbine, compressor and pump are assumed as 0.88 (η T =η COM =η P =0.88). The temperature differences of the heat exchangers are not considered at this stage. This will be discussed below.
[0164] At P 1 =0.1 MPa ( FIG. 11 ), which represents a thermodynamic cycle at the ambient pressure ( FIGS. 5 to 7 ), all four of the efficiencies increase with increasing pressure of the working fluid (P 2 ). However, the increase is only significant at pressures of P 2 <˜10 MPa above which the curves level off. At pressures of P 2 >20 MPa the efficiencies are almost constant. The maximum efficiencies are found to be E E =0.507, E Sup =0.640, E′ E =0.459 and E′ Sup =0.569, respectively.
[0165] At pressures of P 1 =0.2-2.0 MPa ( FIGS. 12 to 15 ), which represent thermodynamics cycles at low pressure ( FIG. 8 ), the results are similar to the case at the ambient pressure (see FIG. 11 ). That is, all four of the efficiencies increase sharply with increasing P 2 until P 2 reaches 10 MPa when further increase in the efficiencies is very small. A comparison between FIG. 11 and FIGS. 12 to 15 reveals that the efficiencies at P 1 =0.2-2.0 MPa are lower than those at P 1 =0.1 MPa.
[0166] At P 1 =4.0-20 MPa ( FIGS. 16-18 ), which represent thermodynamics cycles at high pressures ( FIG. 9 ), the efficiencies of the practical cycle without superheating (E′ E ) are significantly lower than those for P 1 <2.0 MPa owing to the consumption of compression of the input air. The efficiencies of the practical cycle with superheating (E′ Sup ) are high because the heat from the superheating is treated as a waste and a large proportion of the liquid air can be produced by the CES.
[0167] From the above analysis, it can be concluded that P 2 should be higher than 10 MPa. However, the selection of P 2 may be limited by the mechanical feasibility. At present, pressurisation of air to 20 MPa is very common practice in the air separation and liquefaction plants without any engineering difficulties. According to the analysis, P 2 =20 MPa is recommended for the CES as pressures higher than 20 MPa lead to a very marginal increase in efficiency. As a consequence, the following analyses are all based on P 2 =20 MPa.
Pressure of the Input Air (P 1 )
[0168] The actual efficiencies of CES without and with superheating are plotted in FIGS. 19 and 20 respectively as a function of pressure of the input air (P 1 ) for the given pressure of the working fluid (P 2 =20 MPa). Three efficiencies of the turbine, compressor and pump (η T =η P =η COM =0 0.80, 0.84, 0.88) are considered. From inspection of these figures it can be seen that the actual efficiencies increase with increasing efficiencies of the three components (turbine, compressor and pump) with and without superheating. Without superheating, the maximum efficiency occurs at the ambient pressure (P 1 =0.1 MPa) and the efficiency (E′ E ) decreases sharply with increasing input air pressure. With superheating, the efficiency decreases sharply first with increasing input air pressure (P 1 ) between 0.1 and 0.4 MPa. A further increase of P 1 between 0.4 and ˜2 MPa leads to little change in the efficiency. However, a further increase in P 1 to ˜4 MPa results in a large increase in the efficiency due to production of a large proportion of liquid air. A further increase in P 1 beyond 4 MPa leads to a decrease in the efficiency due to increasing compression work. There are two peaks in the efficiency plots with the peak values depending on the efficiency of three components (turbine, compressor and pump). For an efficiency of the components of 0.88, the best efficiency of CES occurs at P 1 =−4 MPa. For an efficiency of the components of 0.80 and 0.84, the best CES efficiency occurs at P 1 =0.1 MPa.
[0169] Therefore, if no waste heat is used by the CES system, P 1 =0.1 MPa should be selected as the working pressure of the input air, as the efficiency is highest and there is no need for a compressor, hence reducing the capital investment and maintenance costs. As a result of this analysis, the following analyses are conducted under the two pressure conditions of P 1 =0.1 MPa and P 1 =4.0 MPa.
Efficiency of Turbine (η T )
[0170] As mentioned above, two sets of conditions are considered, namely, (P 1 =0.1 MPa, P 2 =20 MPa), and (P 1 =4.0 MPa, P 2 =20 MPa). The efficiencies of the compressor and pump are taken as 0.88 (η COM =η P =0.88). The ambient temperature is assumed as T 0 =300K, the superheat temperature is T 9 =400K. The temperature differences across the heat exchangers are not considered. Simulations are performed with seven turbine efficiencies of 0.68, 0.72, 0.76, 0.80, 0.88, 0.92, 0.96 and 1.00 and the results are illustrated in FIGS. 21 and 22 , without and with heat recycle respectively. The efficiencies of CES for both cases increase monotonically with increasing efficiency of the turbine. However, the dependence of the efficiency of the CES is a function of P 1 , the turbine efficiency and the use of waste heat. An increase in the efficiency of the turbine by one percent leads to an increase in the CES efficiency by 0.318% for P 1 =0.1 MPa without heat recycle, an increase of 0.690% for P 1 =0.1 MPa with heat recycle, an increase of 0.428% for P 1 =4.0 MPa without the heat recycle, and an increase of by 2.742% for P 1 =4.0 MPa with heat recycle.
[0171] The figures also show that the rate of increase in the CES efficiency at P 1 =0.1 MPa is lower than that at P 1 =4.0 MPa, indicating that the cycle efficiency at P 1 =4.0 MPa relies more on the efficiency of the turbine than does the cycle efficiency at P 1 =0.1 MPa.
[0172] If there is no waste heat, the CES efficiency at P 1 =0.1 MPa is higher than that at P 1 =4.0 MPa for a turbine efficiency of from 0.68 to 1.0. This indicates that P 1 =0.1 MPa should be used for the CES operation in the absence of the waste heat recycle.
[0173] If waste heat is used, the CES efficiency at P 1 =0.1 MPa is lower than that at P 1 =4.0 MPa for a turbine efficiency over 0.80, but the reverse is seen when the turbine efficiency is lower than ˜0.8. As a consequence, there is a need for optimisation.
Efficiency of Compressor (η COM )
[0174] The effect of the compressor efficiency on the CES efficiency is illustrated in FIGS. 23 and 24 , without and with heat recycle respectively. Simulations are carried out for seven compressor efficiencies of 0.68, 0.72, 0.76, 0.80, 0.88, 0.92, 0.96 and 1.00 with the following conditions: P 1 =0.1 or 4.0 MPa, P 2 =20 MPa, T 0 =300K, T 9 =400K, and η T =η P =0.88. The temperature differences across the heat exchangers are not considered.
[0175] The efficiency of the CES cycle for P 1 =0.1 MPa and P 2 =20 MPa is constant as no compression of the input air is needed for P 1 =0.1 MPa. The efficiency of the CES at P 1 =4.0 MPa and P 2 =20 MPa increase monotonically with increasing efficiency of the compressor. An increase in the compressor efficiency by one percent leads to an increase in the CES efficiency by 0.717% for P 1 =4.0 MPa without heat recycle, and an increase in the CES efficiency by 1.056% for P 1 =4.0 MPa with heat recycle. This indicates that for P 1 =4.0 MPa, the efficiency of the compressor contributes significantly to the CES efficiency.
[0176] From FIG. 23 , one can see that the efficiency of the CES at P 1 =0.1 MPa is much higher than that at P 1 =4.0 MPa when there is no waste heat recycle. If the waste heat is available, then FIG. 24 shows that the efficiency of the CES cycle at P 1 =0.1 MPa is lower than that at P 1 =4.0 MPa if the efficiency of the compressor is higher than 0.78, and the reverse is seen for compressor efficiencies lower than 0.78.
Efficiency of Pump (η P )
[0177] Simulations are performed on seven pump efficiencies of 0.68, 0.72, 0.76, 0.80, 0.88, 0.92, 0.96 and 1.00 for P 1 =0.1 or 4.0 MPa, P 2 =20 MPa, T 0 =300K, T 9 =400K and η T =η COM =0.88. The temperature differences across the heat exchangers are not considered. The results are illustrated in FIGS. 25 and 26 , without and with heat recycle respectively, from which one can see that the efficiencies of both CES cycles increase monotonically with increasing pump efficiency. However, the increase is very small; an increase in the pump efficiency by one percent only leads to an increase in the efficiency of the CES cycle by 0.025% for P 1 =0.1 MPa without heat recycle, by 0.068% for P 1 =0.1 MPa with heat recycle, by 0.022% for P 1 =4.0 MPa without heat recycle, and by 0.072% for P 1 =4.0 MPa with heat recycle.
[0178] This indicates that the efficiency of the CES depends little on the efficiency of the pump because the work consumed by the pump is about an order of magnitude smaller than that of turbine and the compressor.
Efficiency of Air Separation Plant (η A )
[0179] FIGS. 27 and 28 show the efficiencies of the CES as a function of energy consumption per kilogram of liquid air produced. Six levels of energy consumption of 0.400, 0.375, 0.350, 0.325, 0.300 and 0.275 kWh/kg are considered, which correspond respectively to an efficiency of the air separation plant of η A =0.0.516, 0.559, 0.602, 0.645, 0.688 and 0.731. The rationale for these levels of energy consumption is that the current energy consumption of liquid air production is ˜0.4 kWh/kg, and it is expected to decrease to ˜0.28-0.3 kWh/kg by 2010˜2020. Other conditions are P 1 =0.1 or 4.0 MPa, P 2 =20 MPa, T 0 =300K, T 9 =400K and η T =η P =η COM =0.88.
[0180] The results show that the efficiency of the CES increases monotonically with a decrease in the energy consumption of cryogen production. An increase in the efficiency of the air separation plant by one percent results in an increase in the efficiency of the CES cycle by ˜0.972% for P 1 =0.1 MPa without heat recycle, an increase in the efficiency of the CES cycle by ˜1.181% for P 1 =0.1 MPa with heat recycle, an increase in the efficiency of the CES cycle by 0.590% for P 1 =4.0 MPa without heat recycle, and an increase in the efficiency of the CES cycle by 1.381% for P 1 =4.0 MPa with heat recycle.
[0181] Compared with efficiencies of the turbine, compressor and pump, the efficiency of the air liquefaction plant is a more important factor contributing significantly to the overall efficiency of the CES.
[0182] If the energy consumption of the liquid air production were reduced to ˜0.28 kWh/kg, then the efficiency of the CES without waste heat recycle would be increased to ˜0.670 and that with waste heat recycle to ˜0.951.
[0183] Accordingly, the results of the above parametric analysis show that P 1 =0.1 MPa and P 2 =20.0 MPa give the best performance for cases without waste heat recycle. The results also show that P 1 =4.0 MPa and P 2 =20.0 MPa could give a better performance for cases with waste heat recycle than P 1 =0.1 MPa and P 2 =20.0 MPa could do, depending on the efficiencies of the components of the CES. The efficiencies of the turbine (η T ), the compressor (η COM ), and the air separation plant (η A ) are shown to be the most important parameters in determining the overall CES efficiency, whereas the pump efficiency (η P ) has very little influence on the performance of CES.
[0184] Two parts of energy have been incorporated into the total possible energy from liquid air: a) isothermal expansion of compressed gas to ambient pressure and b) cold exergy utilisation by pre-cooling the air input for the separation and liquefaction system. For a simple idealised case (P 1 =0.1 MPa, P 2 =20 MPa, T=300 K), the ideal work from liquid air could be ˜740 kJ/kg that includes the contribution of a) 450 kJ/kg and b) 290 kJ/kg.
[0185] For the gas expansion work (450 kJ/kg) non-isothermal expansion is inevitable. An external heat source has to be added to maintain a high isothermity. A conventional turbine may achieve energy efficiency up to 85% under optimised conditions. It is visible that similar efficiency could be achieved for the proposed turbine applications. However, due to the very high pressures ˜200 bar involved, multi-stage expansion could be considered. The nearly-ambient operation temperature of the turbine also requires considerations of the sealing and lubrication issues.
[0186] For the recycling of the cold exergy (290 kJ/kg) the amount of the cold exergy that can be recycled is dependent on the a) operational pressures model, b) charging and discharging modes, and c) existence of extra cold energy storage system.
[0187] For the operational pressure models, two optimum cases have been identified: I) input air at 0.1 MPa and the working fluid at 20.0 MPa for operation temperature ˜300 k (no waste heat added) and II) input air at 0.1 MPa or 4.0 MPa and working fluids at 20.0 MPa for operation temperature ˜400 K (with a waste heat recycle). Take the optimized case I) for example (P 1 =0.1 Mpa, P 2 =20 Mpa and T=300K), for an ideal compression (dS=0), the temperature of liquid air after compressing to 20 MPa is ˜84 K, which is the lowest temperature that incoming air can get. The liquefaction process needs to remove ˜230 kJ/kg (sensible heat) and another ˜200 kJ/kg (latent heat) at saturation temperature, e.g. 78 K for air under 1 bar. The only work that can be saved through a heat exchanger is some of the work needed to reduce temperature from ambient to ˜84 K (this normally involves multi-stage compression and throttling for a liquefaction factory). Approx. 50% of the energy (latent heat+some sensible heat) for air liquefaction can not be extracted by the cold energy from the heat exchanger. The extra electricity needed is ˜0.2 kWh/kg air during discharging hours if a 0.4 kWh/kg industrial rate is assumed.
[0188] For the optimized case II) where the waste heat is utilized, the analysis will be the same as above for the incoming air at 0.1 MPa (P 1 =0.1 MPa, P 2 =20 MPa and T=400K), but different for the incoming air pressure at 4 MPa (P 1 =4 MPa, P 2 =20 MPa and T=400K). Since the saturation temperature is ˜131K at 4 Mpa, incoming air can be cooled down directly to the liquid state through a heat exchanger, which means no extra electricity is needed for manufacturing liquid air during peak hours. However this comes with the penalty of the compression work needed to bring air to 4 Mpa. For a pure isothermal compression, ˜0.328 MJ/kg, ˜0.1 kWh electricity, is needed. The temperature rise is also significant: for an adiabatic compression with compressor efficiency of 0.9, the temperature rise is ˜620K. The temperature rise reduces to 283 K and 132K respectively for a poly constant of 1.2 and 1.1. Extra cooling facilities are requested for the compressor to achieve a nearly-isothermal compression.
[0189] The amount of cold energy recycled is also dependent on the flow rate ratio during charging and discharging periods. The cold exergy application (in the energy release process) is based on the simultaneous cooling of incoming air (in the energy storage process) in a liquefaction unit. In principle these two events do not occur at the same time. For a typical energy storage system, the duration of the energy release process is only a couple of hours in peak times. To maintain safety and extend the running time, a typical liquefaction unit will operate full load at off-peak time and continue to operate at low load at other times. For a model with 8 hrs of discharging and 16 hrs of charging, the steady flow ratio is ˜2:1. If running at a 50% load during peak times, the flow rate ratio is increased to 4:1. For every kilogram of liquid air produced at peak times, only the sensible heat ˜230 kJ/kg-air can be cooled down by the evaporation of liquid air for the optimized operational pressure case I). Therefore, a large amount of cold energy will not be fully utilized. The shorter the discharging ratio, the larger the amount of cold energy wasted. To fully utilize the energy, the load for liquefaction could be increased but this would risk the consumption of more electricity at peak times.
[0190] Alternatively, the cold energy could be stored. During the discharging period, part of the cold energy could be used to pre-cool the incoming air. At the same time, the extra part of the cold energy will be stored in a thermal energy storage system (TES) that will release cold during the off-peak time to pre-cool the incoming air. This could maximize the opportunities of using cold energy. The storage material may include phase change materials, cryogenic storage materials and others. The storage material is chosen based on its thermal conductivity, specific heat, thermal diffusivity, density, and kinetic behaviour etc. The rate of heat absorption and releasing is directly related to the energy efficiency especially for the phase change materials. The energy storage system may be in the form of fixed bed, suitable geological sites and others. The storage efficiency may be influenced by the properties of the storage materials, the storage temperature and pressure, and the heat transfer coefficient between gas and storage materials.
Parametric Analysis—CPS
[0191] A computational code has been written in the Fortran 90 environment to simulate the influences of various parameters on the performance of the CPS system. The code is written for thermodynamics cycles operated between pressures above the ambient pressure and 38 bar (see FIG. 10 a ), which can also be used for the high pressure case (see FIG. 10 b ). Seven parameters have been considered including:
Pressure of the input air 1 (P 1 ), Ambient temperature (T 0 ), Efficiency of the turbine (η T ), Efficiency of the compressor (η COM ), Efficiency of the pump (η P ), Polytropic coefficient of compression (n), Non-isothermicity of expansion in turbine.
[0199] In the simulations, the pressure of working fluid is taken as 200 bar, the temperature of hot air/water supplied by CPS as 328 K(55° C.), the temperature of cold air for air condition supplied by CPS as 285 K (12° C.), the temperature of cold air for food refrigeration supplied by CPS as 249 K (−24° C.), the coefficient of performance (COP) of the heat pump (ζ) as 3.0, the COP of cooling air for air conditioning (ε 1 ) as 5.0, and the COP of refrigeration (ε 2 ) as 3.0.
Pressure of Input Air 1 (P 1 )
[0200] The ideal and actual efficiencies of CPS are plotted in FIG. 29 under 14 different pressures of the input air 1 (P 1 -1.0 bar, 2.0 bar, 3.0 bar, 4.0 bar, 6.0 bar, 8.0 bar, 10 bar, 12 bar, 14 bar, 16 bar, 18 bar, 20 bar, 30 bar, 40 bar). The ambient temperature is taken as 300K, the polytropic coefficient of the compressor is taken as 1.2 and three efficiencies of the turbine, compressor and pump are considered (η T =η P =η COM =0.88, 0.84, 0.80).
[0201] From inspection of FIG. 29 , it can be seen that the efficiency of CPS increases with increasing efficiencies of the three components (turbine, compressor and pump). The efficiency increases first with increasing pressure of input air 1 and then decreases after reaching a peak. The maximum efficiency is found to be 0.793, 0.679, 0.646, 0.613 when η COM =1 (ideal), 0.88, 0.84 and 0.80, respectively. For an ideal case, the peak efficiency of the CPS occurs at P 1 =˜14 bar. The optimal pressure of input air 1 at which the peak occurs decreases with decreasing efficiency of the components, namely, P 1 =8 bar for 0.88, ˜6 bar for 0.84 and 0.80.
[0202] A high pressure of the input air 1 can produce a high proportion of liquid air and therefore a further increase in the efficiency of CPS. However, a high pressure of the input air 1 also consumes more compression work. Therefore, an optimal pressure of the input air 1 should be selected for the best CPS performance. Since the optimal pressure is not significantly different for the three realistic efficiencies of 0.88, 0.84 and 0.80, the pressure of the input air 1 is selected as 8 bar, and the following calculations are based on this pressure. At P 1 =8 bar, P 2 =200 bar, η T =η P =η COM =0.88, the maximum energy efficiency of CPS is 67.7%, and the specific outputs of the work, heat and cold of the CPS are 401.9 kJ/kg, 29.40/kg, 342.8 kJ/kg, respectively. It can be seen that the amount of cold produced by CPS is very large. Therefore, the CPS is particularly suitable for refrigeration boats.
Ambient Temperature (T 0 )
[0203] FIG. 30 shows the influence of the ambient temperature on the efficiency of the CPS at P 1 =8 bar and P 2 =200 bar for five ambient temperatures of 270K, 280K, 290K, 300K and 310K with n=1.2 η T =η P =η COM =0.88. When the ambient temperature is 270K, 280K or 290K, it is considered unnecessary to account for cool air for air conditioning. It is apparent that the efficiency of CPS increases monotonically with increasing ambient temperature. When the ambient temperature increases from 270K to 310K, the efficiency of the CPS is increased by 14.9%. Due to the utilisation of cold energy for air conditioning at temperatures higher than 290K, there is a sharp increase in the efficiency from 290K to 300K. It is therefore concluded that the CPS performs better in locations with a high ambient temperature such as tropical regions.
Efficiency of Turbine
[0204] FIG. 31 shows the influence of the efficiency of the turbine on the overall efficiency of the CPS for seven values of η T =0.68, 0.72, 0.76, 0.80, 0.88, 0.92, 0.96 and 1.00 with η COM =η P =0.88, n=1.2, T 0 =300K, P 2 =200 bar, and P 1 =8 bar. The efficiency of CPS increases almost linearly with increasing efficiency of the turbine. An increase in the efficiency of the turbine by 1% leads to an increase in the CPS efficiency by 0.738%. The efficiency of the turbine is therefore a key parameter for the CPS efficiency.
Efficiency of Compressor (η COM )
[0205] The effect of the compressor efficiency on the CPS efficiency is illustrated in FIG. 32 . Simulations are carried out for seven compressor efficiencies of 0.68, 0.72, 0.76, 0.80, 0.88, 0.92, 0.96 and 1.00 with P 1 =8 bar, P 2 =200 bar, T 0 =300K, η T =η P =0.88 and n=1.2. The efficiency of the CPS increases monotonically with increasing efficiency of the compressor. An increase in the compressor efficiency by 1% leads to an increase in the CPS efficiency by 0.09%. Therefore the efficiency of the compressor does not contribute significantly to the CPS efficiency. This is because the amount of work consumed by the compressor is small due to the relatively low working pressure of input air 1 compared to that of the working fluid, and the relatively low flow rate of input air 1 compared to that of the working fluid due to a considerable part of the cold energy of the working fluid being used to provide cold air for air conditioning and refrigeration.
Efficiency of Pump (η P )
[0206] The effect of the pump efficiency on the CPS efficiency is illustrated in FIG. 33 . Simulations are performed on seven pump efficiencies of 0.68, 0.72, 0.76, 0.80, 0.88, 0.92, 0.96 and 1.00 for P 1 =1 bar, P 2 =200 bar, T 0 =300K, η T =η COM =0.88 and n=1.2. The efficiency of the CPS increases monotonically with increasing pump efficiency. However, the rate of increase is very small; an increase in the pump efficiency by 1% only leads to an increase in the CPS efficiency by 0.0625%. Therefore the efficiency of the CPS depends little on the efficiency of the pump.
Polytropic Coefficient of Compression (n)
[0207] Simulations are performed on seven polytropic coefficients of 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, and 1.35 for P 1 =1 bar, P 2 =200 bar, T 0 =300K, η T =η COM =η p =0.88. The results are shown in FIG. 34 , from which it can be seen that the efficiency of the CPS changes little with increasing polytropic coefficient. This is because the amount of work consumed by the compressor is small, and the compression heat is recycled by the input air 2 .
Isothermicity of Expansion (γ)
[0208] Five values of the isothelinicity of the expansion process in the turbine of 0.80, 0.85, 0.90, 0.95, 1.0 for P 1 =1 bar, P 2 =200 bar, T 0 =300K, η T =η COM =η P =0.88 are simulated and the results are shown in FIG. 35 . The efficiency of the CPS increases almost linearly with increasing isothermicity. An increase in the isothermicity by 1% gives an increase in the CPS efficiency by 0.72%. The isothermicity of the expansion is therefore a key parameter for the CPS efficiency.
Heat Transfer Analysis—CES
[0209] The heat exchangers are critical components of the CES. Heat exchangers are widely used in the cryogenics and air liquefaction industries, which has led to establishment of a substantial technology base. In general, the following factors are considered when designing a heat exchanger:
[0000] (1) Heat transfer requirement
(2) Efficiency or temperature differences of the exchanger
(3) The dimensions of the space available
(4) The need for low heat capacity
(5) The cost
(6) The importance of pressure drop
(7) The operating pressure
[0210] In the following analysis, focus is on the assessment of heat transfer requirements, type and size of the exchangers and influences of various factors on the performance heat exchangers. The following assumptions are made:
[0000] (1) Thermodynamic equilibrium between fluid phases
(2) Even flow distribution within heat exchanger
(3) Fully developed turbulent flow
(4) Adiabatic shell wall
(5) Zero axial conduction
(6) No radiation between hot and cold fluids
(7) Constant overall heat transfer coefficient.
[0211] Considering a heat exchanger that exchanges an amount of heat, Q, between a hot and a cold fluid, the volume of the heat exchangers can be assessed by:
[0000]
V
=
S
ϑ
=
Q
ϑ
q
=
Q
ϑ
U
_
Δ
T
_
[0000] where V represents the volume of the heat exchanger, S is the heat transfer area, is the ratio of the compactness of heat exchangers defined as
[0000]
ϑ
=
S
V
,
[0000] q is the heat flux, Ū is the overall average heat transfer coefficient, and Δ T is the average temperature difference between the hot and cold fluids. Considering a tube-in-shell configuration, the overall heat transfer coefficient Ū may be obtained by:
[0000]
1
U
_
=
1
U
i
+
1
U
w
+
1
U
o
[0000] where U i is the heat transfer coefficient between the tube wall and the tube side fluid, U o is that between the tube wall and the shell side fluid, and U w accounts for the heat conductivity across the tube wall expressed by:
[0000]
U
w
=
λ
δ
[0000] with λ,δ respectively the wall thermal conductivity and wall thickness. There is a large amount of literature on the calculations of the heat transfer coefficients U i and U o . For a turbulent flow in a smooth cylindrical tube, the heat transfer coefficient between the tube side fluid and the tube wall is given approximately by Nu=0.023 Re 0.08 Pr 0.4 where Nu is the Nusselt number defined as
[0000]
Nu
=
UD
λ
,
[0000] Re is the Reynolds number defined as
[0000]
Re
=
ρ
uD
μ
,
[0000] and Pr is the Prandtl number given by
[0000]
Pr
=
v
α
,
[0000] where ρ is the density of the fluid, D is the diameter of the tube, v is the fluid kinematic viscosity, α is the fluid thermal diffusivity and μ is the fluid dynamic viscosity. For the pressure drop of a Newtonian fluid in a smooth cylindrical tube, the frictional pressure drop can be calculated by
[0000]
Δ
p
=
2
f
ρ
u
2
L
D
[0000] where f is the friction factor, u is the flow velocity, L is the length of the tube. For a turbulent flow in tubes, the Blasius equation is generally used for estimating f in a wide range of Reynolds number:
[0000]
f
=
0.079
Re
0.25
.
[0000] The flow in the heat exchangers in the CES of the present invention is likely to be in the two-phase region for which a full analysis of the pressure drop requires a 3-dimensional description of the flow and heat transfer involving phase changes. An engineering approach is to calculate first the pressure with a homogeneous model and then use a safety factor of 3˜5 in the design of the heat exchangers.
Heat Transfer Requirement
[0212] The CES system could have up to four heat exchangers:
[0000] (1) Heat exchanger 1 ( 350 ): for input air to extract cold from the working fluid (and take heat from the ambient air)
(2) Heat exchanger 2 ( 340 ): for waste heat to superheat the working fluid
(3) Heat exchanger 3: for the turbine to absorb heat from atmosphere
(4) Heat exchanger 4: for the compressor to ensure isothermal operation.
[0213] The specific heat transfer requirements for the four heat exchangers are, respectively:
[0000] Q 1 =h 8 −h 7 Heat Exchanger 1
[0000] Q 2 =h 9 −h 8 Heat Exchanger 2
[0000] Q 3 =T 9 ( S 10 −S 9 ) Heat Exchanger 3
[0000] Q 4 =T 0 ( S 0 −S 2 ) Heat Exchanger 4
[0214] By using the above four equations, the specific heat transfer requirements under different conditions are obtained and illustrated in Table 1, where the ambient temperature is 300 K and the superheat temperature is 400 K.
[0215] From table 1 it can be seen that for P 1 =0.1 MPa, since there is no need for a compressor, Q 4 is zero. If there is no superheat, Q 2 is zero. The total quantity of specific heat transfer requirement for a simple cycle without superheating at P 1 =0.1 MPa is therefore 858.6 kJ/kg. The maximum specific heat transfer requirement is 1308.2 kJ/kg, which corresponds to the cycle with superheating at P 1 =4.0 MPa. In the following sections, analyses will be based on the above two sets of heat transfer requirements.
[0000]
TABLE 1
Specific heat transfer requirement at different conditions
P2
P1
Super
Q 1
Q 2
Q 3
Q 4
(MPa)
(MPa)
Heat
(kJ/kg)
(kJ/kg)
(kJ/kg)
(kJ/kg)
20.0
0.1
No
368.9
0.0
489.7
0.0
20.0
0.1
Yes
368.9
119.8
630.8
0.0
20.0
4.0
No
310.3
0.0
489.7
247.3
20.0
4.0
Yes
310.3
119.8
630.8
247.3
Preliminary Design of Heat Exchanger
[0216] As mentioned above, there is a substantial technology base for heat exchangers and there are a lot of types of heat exchangers available for the cryogenics and air separation and liquefaction industries. Tube-in-shell and plate-and-fin heat exchangers are among the most widely used types. Tube-in-shell heat exchangers are commonly used at relatively high temperatures. Tube-in-shell heat exchangers have a high transfer coefficient ranging from ˜300 to ˜3000 W/m 2 K when the fluid phase in both the shell and tube sides is liquid. A common technique to improve the performance of tube-in-shell heat exchangers is to foil fins helically around the tube thus forming a tube and fin heat exchanger in order to increase the ratio of compactness and the heat transfer coefficient. This is especially effective when the fluid is in a gaseous state in one or both sides of the heat exchanger. In addition, the temperature difference between hot and cold fluids is relative high (˜15 K), which leads to a relatively low efficiency.
[0217] Plate and fin heat exchangers have an advantage of a high degree of compactness, and a low temperature difference between the hot and cold fluids. This type of heat exchanger can be made of aluminium alloy so the capital cost is relatively low. Plate and fin heat exchangers are suitable for use in the cryogenic field because the innate flexibility of this type of heat exchanger allows the use of a multiplicity of fluids in the same unit. Plate and fin heat exchangers comprise flat plates of aluminium alloy separated by corrugated fins. The fins are brazed onto the plate by means of a thin foil of the same alloy as the plate with added silicon to cause melting of the foil at low temperatures and so to bond the fins to the plate. Aluminium is generally favoured on grounds of cost but copper is also acceptable. Due to the large ratio of compactness of ˜250˜5000 m 2 /m 3 , plate and fin heat exchangers are the most widely used heat exchangers in the air separation and liquefaction industry with a typical heat transfer coefficient of ˜30˜500 W/m 2 K and a temperature difference of up to ˜2˜6 K between the hot and cold fluids.
[0218] Other types of heat exchangers that could be used include regenerators, coiled tube heat exchangers, multiple tube heat exchangers, and coaxial tube heat exchangers.
[0219] The following is an estimation of the size of the heat exchangers based on the performance of the plate and fin type. The overall average heat transfer coefficient Ū is taken as 100 W/m 2 K; the average temperature difference between hot and cold fluids, Δ T , is assumed as 2 K; the ratio of compactness, , is taken as 1000 m 2 /m 3 . The compactness could be much higher, so the estimation is on the conservative side. The maximum heat transfer requirements, H R , with and without superheating are respectively given as 858.6 and 1308.2 kJ/kg on the basis of the above calculation. Two cases of the CES with electricity storage volumes (Ev) of 1 MWh and 500 MWh are considered in the estimation. The operating time (O T ) of the CES is assumed as 8 hours. This is according to peak hour operation. Different duty cycles could be used and should not greatly impact efficiency.
[0220] For Case 1 of the CES with the storage volume of 1 MWh, the heat transfer requirement without superheating is given by:
[0000]
Q
=
E
V
H
R
O
T
E
D
=
0.149
MW
[0000] where E D is the energy density of liquid air (kJ/kg). The total size of the heat transfer exchangers can be calculated by:
[0000]
V
=
Q
ϑ
U
_
Δ
T
_
=
0.745
m
3
.
[0221] For Case 1 with the superheating, the heat transfer requirement will be:
[0000]
Q
=
E
V
H
R
O
T
E
D
=
0.186
MW
.
[0000] The total size of the heat transfer exchangers will be:
[0000]
V
=
Q
ϑ
U
_
Δ
T
_
=
0.929
m
3
.
[0222] For Case 2 of the CES with a storage volume of 500 MWh, the heat transfer requirement without superheating is:
[0000]
Q
=
E
V
H
R
O
T
E
D
=
74.5
MW
.
[0000] The total size of the heat exchangers will be:
[0000]
V
=
Q
ϑ
U
_
Δ
T
_
=
372.5
m
3
.
[0000] If the heat exchanger is assumed to be cubic in shape, the length of each side will be 7.19 m. If a factor of safety of 4 is given, the length of each side will be 11.41 m.
[0223] For Case 2 of the CES with the storage volume of 500 MWh with superheating, the heat transfer requirement will be:
[0000]
Q
=
E
V
H
R
O
T
E
D
=
93.0
MW
.
[0000] The total size of the heat exchangers will be:
[0000]
V
=
Q
ϑ
U
_
Δ
T
_
=
464.5
m
3
.
[0000] If a cubic shape is assumed, then the length of each side of the heat exchanger will be 7.74 m. If a factor of safety of 4 is given, the length of each side will be 12.29 m.
[0224] The liquid nitrogen viscous pressure drop is reported to be about 0.05 MPa and the pressure drop of input air is about 400 Pa. If a safety factor of 4 is used, then the liquid air pressure drop would be about 0.2 MPa which is about 1.0% of the total pumping pressure, and the pressure drop of the input air would be 1600 Pa which is tiny compared with the compression ratio.
Influence of Temperature Difference Across Heat Exchanger
[0225] FIGS. 36 and 37 show the efficiencies of a CES as a function of temperature differences between hot and cold fluids in heat exchangers for cases with and without superheating, respectively. Six values of the temperature, 0K, 2K, 4K, 6K, 8K, 10K, are simulated. The efficiencies of the CES decrease monotonically with an increase in the temperature difference. When the temperature difference increases by 1 K, the efficiency of the CES decreases by ˜0.37% for P 1 =0.1 MPa without heat recycle, by ˜0.25% for P 1 =0.1 MPa with heat recycle, by ˜0.36% for P 1 =4.0 MPa without heat recycle, and by ˜1.33% for P 1 =4.0 MPa with heat recycle, respectively. Therefore, the temperature difference of hot and cold fluids in the heat exchangers plays a fairly important role in the overall performance of the CES.
[0226] The influence of the temperature of the waste heat used for superheating on the efficiency of the CES for P 1 =0.1 MPa and P 1 =4.0 MPa is illustrated in FIG. 38 . Five values of the temperature, 400K, 450K, 500K, 550K, 600K, are simulated. The selection of the values of the temperature is on the basis of the available waste heat of different types of power plants. For example, the temperature of flue gas of a gas turbine power plant is ˜800 K, the temperature of flue gas of a steam turbine power plant is ˜400K˜500K, the temperature of waste heat from a nuclear power plant is ˜550 K, the temperature of waste heat from a cement kiln is ˜700K, and the geothermic temperature is ˜350K˜500K.
[0227] The efficiency of the CES increases monotonically with an increase in temperature of the flue gas containing the waste heat. If the waste heat temperature increases from 400K to 600K, the efficiency of the CES increases from 0.558 to 0.749 for P 1 =0.1 MPa, and from 0.654 to 1.714 for P 1 =4.0 MPa.
[0228] Making the best utilization of waste heat is therefore a very effective way to improve the performance of the CES. Note that the waste heat is not accounted for as the input energy, hence the efficiency can be more than 100%. In addition, the waste heat can be from geothermal, cement kilns, or other industrial sources.
[0229] FIG. 39 shows the influence of the ambient temperature on the efficiency of the CES for P 1 =0.1 MPa and P 1 =4.0 MPa. Ambient temperatures of 270K, 280K, 290K, 300K and 310K are simulated. The efficiencies of the ideal cycle for P 1 =0.1 MPa, the practical cycle for P 1 =0.1 MPa, the ideal cycle for P 1 =4.0 MPa, and the practical cycle for P 1 =4.0 MPa increase almost linearly with increasing ambient temperature. When the ambient temperature increases from 270K to 310K, the efficiencies of the above mentioned cycles increase by 9.7%, 9.1%, 10.2% and 5.5%, respectively. It is therefore concluded that the CES performs better in locations with a high ambient temperature such as tropical regions.
Heat Dissipation of Cryogen Tank
[0230] The heat dissipation (leakage) of the cryogenic tank is about 1% per day in an insulated Dewar at ambient pressure. If more efforts are taken or cold energy dissipation is utilised, the loss of efficiency of CES due to the dissipation (leakage) may be less than 1% per day. This is important when considering the duration of the energy storage cycle of the CES, i.e. the liquid air must be used within a certain period of time in order to ensure the overall efficiency.
[0231] Table 2 shows the process for calculating CES efficiency for a number of thermodynamic cycles.
[0000]
TABLE 2
Cycle 3
Cycle 4
Cycle 5
Cycle 6
Cycle 7
Cycle 8
Cycle 9
Pressure of Liquid air (MPa)
20
20
20
20
20
20
20
Pressure of Input air (MPa)
4.0
4.0
4.0
4.0
0.1
0.1
0.1
Temperature of working fluid at
400
400
400
400
400
300
300
turbine (K)
Ratio of the input air to the working
0.780
0.780
0.810
0.810
1.69
1.69
1.69
fluid (x) (kg/kg)
Ratio of liquid air produced from the
0.730
0.730
0.724
0.724
0
0
0
input air to the working fluid (xy)
(kg/kg)
Heat exchanger temperature
0
0
5
5
5
5
5
differences (K)
Efficiency of turbine
100%
88.0%
100%
88.0%
88.0%
88.0%
88.0%
Reduction in efficiency of turbine
0
0
0
0
15.0%
15.0%
15.0%
due to non-isothermicity
Efficiency of pump
100%
88.0%
100%
88.0%
88.0%
88.0%
88.0%
Efficiency of compressor
100%
88.0%
100%
88.0%
88.0%
88.0%
88.0%
Reduction of efficiency of
0
0
0
0
15.0%
15.0%
15.0%
compressor due to non-isothermicity
Expansion work (kJ/kg)
615.2
541.4
607.5
534.6
455.6
335.3
335.3
Compression work (Only x kg of
247.2
280.9
256.7
291.7
0
0
0
input air is compressed) (kJ)
Pumping work (kJ/kg)
22.4
25.5
22.4
25.5
25.5
25.5
25.5
Cold energy recycling (kJ/kg)
0
0
0
0
267.2
267.2
267.2
Net work (Only (1-xy) kg of working
345.6
235.0
328.4
217.4
697.3
577.0
577.0
fluid is used in a single cycle) (kJ)
Net flowrate of liquid air (based on
0.270
0.270
0.276
0.276
1.0
1.0
1.0
1 kg of working fluid) (kg)
Energy density (E D ) (kJ/kg)
1280.0
870.3
1189.9
787.7
697.3
577.0
577.0
Energy consumed by air liquefaction
1440
1440
1440
1440
1440
1440
1080
(E C ) (kJ/kg)
Efficiency of CES (E D /E C )
88.9%
60.9%
82.7%
54.7%
48.4%
40.1%
53.4%
Total amount of exergy (E I ) (kJ/kg)
743
743
743
743
743
743
743
Cycle efficiency (E D /E I ) (waste heat
172.3%
117.1%
160.1%
106.0%
93.8%
77.7%
77.7%
is not included as input energy)
Heat Transfer Analysis—CPS
[0232] The heat exchangers play a critical role in the CPS. The flow and heat transfer in the heat exchangers in CPS involves three dimensional, viscous, turbulent and two-phase phenomena. In this analysis, the following assumptions are made:
[0000] (1) Thermodynamic equilibrium between fluid phases
(2) Even flow distribution within heat exchanger
(3) Fully developed turbulent flow
(4) Adiabatic shell wall
(5) Zero axial conduction
(6) No radiation heat transfer between hot and cold fluids
(7) Constant overall heat transfer coefficient.
Heat Transfer Requirement
[0233] The main CPS system has four heat exchangers and the turbine uses an additional heat exchanger for isothermal expansion (see FIG. 4 ):
[0000] (1) Heat exchanger 1 ( 540 ): for input air 1 to extract cold from the working fluid for condensing the input air 1 .
(2) Heat exchanger 2 ( 535 ): for input air 1 and 4 to extract cold from the working fluid
(3) Heat exchanger 3 ( 530 ): input air 1 , 3 and 4 to extract cold from the working fluid
(4) Heat exchanger 4 ( 525 ): for input air 1 and 2 to absorb compression heat
(5) Heat exchanger 5: for turbine to absorb heat from atmosphere
[0234] The specific heat transfer requirements for the five heat exchangers are, respectively:
[0000] Q 1 −x 1 ( h 6 −h 7 ) Heat Exchanger 1
[0000] Q 2 =x 1 ( h 5′ −h 6 )± x 4 ( h 10 −h 11 ) Heat Exchanger 2
[0000] Q 3 =x 1 ( h 5 −h 5′ )+ x 3 ( h 0 −h 10 )+ x 4 ( h 0 −h 10 ) Heat Exchanger 3
[0000] Q 4 =x 1 ( h 4 −h 5 ) Heat Exchanger 4
[0000] Q 5 =T 0 ( S 0 −S 3 ) Heat Exchanger 5
[0235] By using the above equations, the specific heat transfer requirements for Q 1 to Q 5 are 47.9 kJ/kg, 165.9 kJ/kg, 225.4 kJ/kg, 57.8 kJ/kg and 597.7 kJ/kg respectively, where the ambient temperature is 300 K. The maximum specific heat transfer requirement of the entire CPS system, therefore, is 1102.0 kJ/kg. In the following sections, analyses will be based on this value of heat transfer requirements.
Preliminary Design of Heat Exchanger
[0236] The following is an estimation of the size of the heat exchangers based on the performance of the plate and fin type. The overall average heat transfer coefficient Ū is taken as 100 W/m 2 K; the average temperature difference between hot and cold fluids, Δ T , is assumed as 2 K; the ratio of compactness, , is taken as 1000 m 2 /m 3 . The compactness could be much higher, so the estimation is on the conservative side. The maximum heat transfer requirements, H R , is given as 1102.0 kJ/kg on the basis of the above calculation. For a CPS with a work output of 1 kW, the heat transfer requirement is given by:
[0000]
Q
=
1
·
H
R
W
R
·
E
E
=
2.184
kW
[0000] where W R and E E are the maximum specific work of liquid air and the energy efficiency of CPS, respectively. The size of the heat exchanger for a 1 kW work output can be calculated by:
[0000]
V
=
Q
ϑ
U
_
Δ
T
_
=
0.011
m
3
.
[0000] If a factor of safety is given as 4, the size of the heat exchanger for a unit work output would be 0.044 m 3 .
[0237] The liquid nitrogen viscous pressure drop is reported to be about 0.5 bar and the pressure drop of input air was about 400 Pa. If a safety factor of 4 is used, then the liquid air pressure drop would be about 2 bar which is about 1.0% of the total pumping pressure (200 bar), and the pressure drop of the input air would be 1600 Pa (0.016 bar) which is very small compared with the compression ratio (˜0.2% of 8 bar).
Influence of Temperature Difference Across Heat Exchanger
[0238] FIG. 40 shows the efficiency of a CPS as a function of temperature difference between hot and cold fluids in heat exchangers. Six values of the temperature, 0K, 2K, 4K, 6K, 8K, 10K, are simulated. The efficiency of the CPS decreases monotonically with an increase in the temperature difference. When the temperature difference increases by 1 K, the efficiency of the CPS decreases by 0.4%. Therefore, the temperature difference of hot and cold fluids in the heat exchangers plays a fairly important role in the overall performance of the CPS.
Heat Dissipation of Cryogen Tank
[0239] The heat dissipation (leakage) rate of the cryogenic tank is about 1% per day in an insulated Dewar at the ambient pressure. If more efforts are taken or cold energy dissipation is utilised, for example for air conditioning, the loss of efficiency of CPS due to the dissipation (leakage) may be less than 1% per day. The efficiency of heat dissipation as a function of time for four dissipation rates of 1%, 0.75%, 0.50%, 0.25% per day, is shown in FIG. 41 . The efficiency of heat dissipation E dis is defined as
[0000]
E
dis
=
M
ideal
M
ac
[0000] where M ideal refers to the total amount of mass of liquid air without dissipation, and M ac is the actual total amount of mass of liquid air with the dissipation.
[0240] It can be seen that the efficiency of heat dissipation decreases with increasing time and dissipation rate. This indicates that the CPS operation should be within a certain period of time in order to ensure a good overall efficiency. It is essential to decrease the heat dissipation especially for a long term journey. For a dissipation rate of ˜0.5% per day, the total loss over a duration of 30 days is ˜7.5%.
Example of a Lab Scale CES System
[0241] An exemplary small lab scale CES system with a capacity of 100 kWh is illustrated schematically in FIG. 42 . This represents a system at a scale much smaller than the probable size of commercial units and is designed for testing operating parameters and optimising performance of the system. A full scale CES system may contain additional components which are not included in the lab scale system. The system has a 12.5 kW power rating and an 8 hour discharge time. The power rating could also be suitable for the power needs of multiple households in a microgeneration configuration. The 8 hour discharge time (100 KWh stored) is chosen because this is near to the maximum discharge duration required for energy storage applications suggested by bodies such as the Sandia laboratories.
[0242] The experimental system consists of 8 major components, a cryogenic tank 600 , a pump 610 , a heat exchanger 620 , a turbine 630 , a transmission box 640 , a blower 650 , a drier 660 and a three-way valve 670 . The system works as follows:
[0000] 1) Liquid air (working fluid) from a cryogen plant or a storage depot is fed into the cryogenic tank 600 .
2) Working fluid is pumped and heated before flowing into the turbine 630 , where it expands to produce power to drive the blower 650 . The blower 650 has two functions, one is to provide the input air for recovery of the cold energy through the heat exchanger 620 , and the other one is to provide a load to the turbine 630 (acting as a generator).
3) A small fraction of the air from the blower 650 (input air) is introduced to the heat exchanger 620 via the three-way valve 670 and the drier 660 .
4) No liquid air is produced in the lab scale system to reduce the capital cost. This, however, does not affect assessment of the CES performance as the measured data are sufficient for such a purpose.
Thermodynamic Analyses
[0243] The thermodynamic cycle of the lab scale CES system is shown in FIG. 43 . Let T 0 h 0 and S 0 denote respectively the ambient temperature, enthalpy and entropy, the processes and their heat, work and exergy are given in the following:
[0244] 1) 1-2: Pumping of working fluid: The working fluid (liquid air) from the cryogenic tank is pumped from the ambient pressure P 0 to P 2 . The specific work done on the liquid air is:
[0000]
W
1
-
2
=
V
l
(
P
2
-
P
0
)
=
(
P
2
-
P
0
)
ρ
l
.
[0000] The above work can also be expressed by the enthalpy difference between state 2 and state 1: W 1-2 =h 2 −h 1 . The total cold exergy (maximum work availability) of the working fluid at state 1 is: Ex 1 =T 0 (S 0 −S 1 )−(h 0 −h 1 ).
2) 2-3: Isobaric heating of working fluid: The working fluid is heated by the input air from T 2 to T 3 . The specific work done in this process is zero: W 2-3 =0. The specific heat absorbed from the input air is: Q 2-3 =h 3 −h 2 . The exergy released in the process 2-3 is: Ex 2-3 =T 0 (S 3 −S 2 )−(h 3 −h 2 ).
3) 3-4: Expansion of working fluid: The working fluid with a high pressure expands in the turbine to deliver work. If an ideal isothermal process is considered, the specific work done in the process is: W 3-0 =T 0 (S 0 −S 3 )−(h 0 −h 3 ). The specific heat absorbed from the ambient in an ideal isothermal process is: Q 3-0 =T 0 (S 0 −S 3 ). If the expansion of the working fluid is adiabatic, the specific ideal work W ad will be:
[0000]
W
ad
=
k
k
-
1
RT
3
[
P
0
P
2
)
(
k
-
1
)
k
-
1
]
[0000] and there is no heat absorption in the process: Q ad =0. The actual work, however, is expected to be in the range between W 3-0 and W ad . A factor called isothermicity, γ, is often used as an index, which is defined as the ratio of the actual work to the isothermal work:
[0000]
γ
=
W
3
-
4
W
3
-
0
.
[0000] Thus, the actual work W 3-4 can be expressed as: W 3-4 =γW 3-0 =γ[T 0 (S 0 −S 3 )−(h 0 −h 3 )].
4) 6-7: Extraction of cold energy of the working fluid by input air isobarically: The cold energy of the working fluid is extracted by the input air isobarically through the heat exchanger. The specific work done in this process is zero: W 6-7 =0. The cold energy from the working fluid in the process 6-7 is: Q 6-7 =h 6 −h 7 . The exergy obtained by the input air over the process is given by: Ex 6-7 =T 6 (S 6 −S 7 )−(h 6 −h 7 ). From the above analysis, the specific ideal net work output of the cycle should be:
[0000]
W
net
=
W
3
-
4
-
W
1
-
2
+
F
2
F
1
·
Ex
6
-
7
=
γ
T
0
(
S
0
-
S
3
)
-
(
h
0
-
h
3
)
-
(
h
1
-
h
2
)
+
F
2
F
1
·
[
T
6
(
S
6
-
S
7
)
-
(
h
6
-
h
7
)
]
[0000] where F 1 and F 2 are respectively the flowrates of the working fluid and input air, respectively.
[0245] The efficiency of the lab scale CES experimental system can therefore be expressed by:
[0000]
E
C
=
W
net
Ex
1
=
W
3
-
4
-
W
1
-
2
+
F
2
F
1
·
Ex
6
-
7
Ex
1
=
γ
T
0
(
S
0
-
S
3
)
-
(
h
0
-
h
3
)
-
(
h
1
-
h
2
)
+
F
2
F
1
·
[
T
6
(
S
6
-
S
7
)
-
(
h
6
-
h
7
)
]
T
0
(
S
0
-
S
1
)
-
(
h
0
-
h
1
)
[0000] where Ex 1 is the total cold exergy contained in the working fluid. In the actual experimental system, a certain amount of work is needed to pump the input air through the heat exchanger; therefore the work of process 6-7 is not zero. The actual specific net work output should be:
[0000]
W
net
=
W
3
-
4
-
W
1
-
2
+
F
2
F
1
·
Ex
6
-
7
-
F
2
F
1
·
W
6
-
7
=
γ
T
0
(
S
0
-
S
3
)
-
(
h
0
-
h
3
)
-
(
h
1
-
h
2
)
+
F
2
F
1
·
[
T
6
(
S
6
-
S
7
)
-
(
h
6
-
h
7
)
]
-
F
2
F
1
·
W
6
-
7
.
[0000] The efficiency of the lab scale CES system therefore becomes
[0000]
E
C
=
W
net
Ex
1
=
W
3
-
4
-
W
1
-
2
+
F
2
F
1
·
Ex
6
-
7
-
F
2
F
1
·
W
6
-
7
Ex
1
=
γ
T
0
(
S
0
-
S
3
)
-
(
h
0
-
h
3
)
-
(
h
1
-
h
2
)
+
F
2
F
1
·
[
T
6
(
S
6
-
S
7
)
-
(
h
6
-
h
7
)
]
-
F
2
F
1
·
W
6
-
7
T
0
(
S
0
-
S
1
)
-
(
h
0
-
h
1
)
.
Measurement Techniques and Data Processing
[0246] A suitable measurement system is shown schematically in FIG. 42 . There are 20 measurement channels with 7 for thermocouples, 7 for pressure transducers, 2 for flow rates, 1 for electric voltage, 1 for electric current, and 1 for torque/speed. A data acquisition system is linked to a computer for data acquisition, storage and processing. The measurement channels comprise:
(1) T 1 : Temperature of the working fluid at the inlet of the pump 610 . (2) T 2 : Temperature of the working fluid at the outlet of the pump 610 /the inlet of the heat exchanger 620 . (3) T 3 : Temperature of the working fluid at the outlet of the heat exchanger 620 /inlet of the turbine 630 . (4) T 4 : Temperature of the working fluid at the outlet of the turbine 630 . (5) T 5 : Temperature of the air at the inlet of the blower 650 (ambient temperature). (6) T 6 : Temperature of the input air at the inlet of the heat exchanger 620 . (7) T 7 : Temperature of the input air at the outlet of the heat exchanger 620 . (8) P 1 : Static pressure of the working fluid at the inlet of the pump 610 . (9) P 2 : Static pressure of the working fluid at the outlet of the pump 610 /inlet of the heat exchanger 620 . (10) P 3 : Total pressure of the working fluid at the outlet of the heat exchanger 620 /inlet of the turbine 630 . (11) P 4 : Total pressure of the working fluid at the outlet of the turbine 630 . (12) P 5 : Total pressure of the air at the inlet of the blower 650 (ambient pressure). (13) P 6 : Static pressure of the input air at the inlet of heat exchanger 620 . (14) P 7 : Static pressure of the input air at the outlet of heat exchanger 620 . (15) F 1 : Flow rate of the working fluid delivered by the pump 610 . (16) F 2 : Flow rate of the input air through the heat exchanger 620 . (17) V 1 : Electric voltage of the pump 610 . (18) C 1 : Electric current of the pump 610 . (19) ω 1 : Rotary speed of the turbine 630 . (20) M 1 : Output torque of the turbine 630 .
[0267] From the above thermodynamic analyses, it can be seen that seven variables are needed to obtain the actual efficiency of the lab scale experimental system, including W 3-4 , W 1-2 , EX 6-7 , W Blower , EX 1 , F 1 and F 2 . The methodologies for obtaining these parameters follow:
[0000] (1) W 3-4 : actual work output of the turbine: A torque/speed meter is directly connected to the axis of the turbine 630 , and the blower 650 is used as a load. The work output of the turbine 630 is obtained by multiplying the measured torque (M 1 ) and speed (ω 1 ): W 3-4 =M 1 ·ω 1 .
(2) W 1-2 : work consumed by the pump: In the experimental system, the pump 610 is driven by a motor. The actual work consumed by the pump 610 can therefore be obtained by measuring the electric voltage (V 1 ) and current (C 1 ) of the motor: W 1-2 =V 1 ·C 1 . The result of W 1-2 accounts for both the efficiencies of the pump and the motor 610 .
(3) Ex 6-7 : cold exergy recycled by input air: The cold exergy recovered by the input air can be calculated by: Ex 6-7 =T 6 (S 6 −S 7 )−(h 6 −h 7 ). To obtain the entropies and enthalpies of the input air, i.e. S 6 , S 7 , h 6 and h 7 , two thermocouples and two pressure transducers are used in the experimental system at the inlet and outlet of the heat exchanger 620 , respectively. Using the measured data of T 6 , T 7 , P 6 and P 7 , the entropies and enthalpies of the input air can be found from the thermodynamics data tables for the air.
(4) W 6-7 : work needed for pumping the input air: The specific work consumed for pumping the input air is calculated by the pressure difference between the inlet and outlet of the heat exchanger 620 : W 6-7 =P 7 −P 6 .
(5) F 1 : Flow rate of working fluid: The flow rate of the working fluid is measured by the flow meter installed at the inlet of the pump 610 .
(6) F 2 : Flow rate of input air: The flow rate of the input air is measured by the flow meter installed at the outlet of the heat exchanger 620 .
(7) Ex 1 : total cold exergy contained in working fluid: The total cold exergy recovered from the working fluid is calculated by: Ex 1 =T 0 (S 0 −S 1 )−(h 0 −h 1 ). To obtain the entropies and enthalpies of the working fluid, i.e. S 0 , S 1 , h 0 and h 1 , two thermocouples and two pressure transducers are installed at the inlet and outlet of the heat exchanger 620 , respectively. Using the data of T 5 , T 1 , P 5 and P 1 , the entropies and enthalpies of the working fluid can be obtained by referring to the thermodynamic data tables for the air.
[0268] Parameters related to individual components that can be obtained from the experimental CES include:
(1) Cryogenic Tank
[0000]
a. The volume of liquid air can be obtained from a level indicator; the heat dissipation can be calculated from the difference in volume over a known time period.
b. The temperature at the outlet of the cryogenic tank 600 (T 1 )
c. The pressure at the outlet of the cryogenic tank 600 (P 1 )
d. The flow rate of the working fluid (F 1 )
(2) Pump
[0000]
a. The flow rate of the pump 610 (F 1 )
b. The temperature at the inlet (T 1 ) and outlet (T 2 ) of the pump 610
c. The pressure at the inlet (P 1 ) and outlet (P 2 ) of the pump 610
d. The efficiency of the pump 610 :
[0000]
η
P
=
F
1
·
Δ
P
t
V
1
·
C
1
=
F
1
·
(
P
2
-
P
1
)
V
1
·
C
1
(3) Heat Exchanger
[0000]
a. The temperature of the working fluid at the inlet (T 2 ) and outlet (T 3 ) of the heat exchanger 620
b. The pressure of the working fluid at the inlet (P 2 ) and outlet (P 3 ) of the heat exchanger 620
c. The temperature of the input air at the inlet (T 6 ) and the outlet (T 7 ) of the heat exchanger 620
d. The pressure of the input air at the inlet (P 6 ) and outlet (P 7 ) of the heat exchanger 620
e. The flow rate of the working fluid (F 1 )
f. The flow rate of the input air (F 2 )
g. The temperature differences of the working fluid and the input air between the inlet and outlet of the heat exchanger 620 : (T 7 −T 2 ) and (T 6 −T 3 )
h: The pressure differences of the working fluid and the input air between the inlet and outlet of the heat exchanger 620 : (P 7 −P 2 ) and (P 6 −P 3 )
(4) Turbine
[0000]
a. The temperature of the working fluid at the inlet (T 3 ) and the outlet (T 4 ) of the turbine 630
b. The pressure of the working fluid at the inlet (P 3 ) and the outlet (P 4 ) of the turbine 630
c. The output torque (M 1 ) and rotary speed (ω 1 ) of the turbine 630
d. The efficiency of the turbine 630 calculated by:
[0000]
η
T
=
M
1
·
ω
1
F
1
·
(
P
3
-
P
4
)
e. The isothermicity of the expansion in the turbine 630 calculated by:
[0000]
γ
=
M
1
·
ω
1
T
0
(
S
0
-
S
3
)
-
(
h
0
-
h
3
)
(5) Blower
[0000]
a. The temperature of air at the inlet (T 5 ) and outlet (T 6 ) of the blower 650
b. The pressure of air at the inlet (P 5 ) and outlet (P 6 ) of the blower 650
c. The input torque (M 1 ) and rotary speed (ω 1 ) of the blower 650 (driven by the turbine 630 ).
Detailed Thermodynamic Analyses of the Components of the Small Scale Lab CES
[0293] (1) Cryogenic tank: The flow rate of the fuel (liquid air) can be calculated by:
[0000]
F
l
=
P
o
η
·
E
D
·
ρ
l
[0000] where F l , P o , η, E D and ρ l are the flowrate of liquid air, power of the system, efficiency of the turbine 630 , energy density of liquid air and density of liquid air, respectively. The volume of the fuel tank 600 is given by:
[0000]
V
l
=
S
f
·
F
I
·
O
t
E
dis
[0000] where S f , V l , O t , E dis are respectively the safe factor, volume of liquid air, operating duration and efficiency of heat dissipation of the tank. If a cubic tank is assumed, the length of each side, d, is
[0000]
V
l
3
.
[0294] If the working pressure of the working fluid is 20 MPa, the ambient temperature is 300 K, the ideal specific energy density of liquid air is ˜455 kJ/kg, the density of liquid air at the ambient pressure is ˜876 kg/m 3 , the efficiency of the turbine 630 is 0.8 and the total power of the lab scale experimental system is 12.5 kW, the flow rate of liquid air is:
[0000]
F
l
=
P
o
η
·
E
D
·
ρ
l
=
12.5
0.8
·
455
·
876
=
141.0
l/h
.
[0000] If a safe factor of 1.3 is considered and the efficiency of heat dissipation is taken as 0.95, then the volume of the cryogenic tank 600 for a total capacity of 100 kWh is:
[0000]
V
l
=
S
f
·
F
I
·
O
t
E
dis
=
1.3
×
0.141
×
8
0.95
=
1.55
m
3
.
[0000] If a cubic tank is assumed, the length of each side is 1.14 m.
[0295] Due to heat transfer, liquid air evaporates in the cryogenic tank 600 and the pressure of liquid air at the outlet of the tank 600 (inlet of the pump 610 ) is higher than the ambient pressure which leads to a decrease in the work consumed by the pump 610 . Given that self-pressurisation of the cryogenic tank 600 is unavoidable, a safety valve is included to relieve the pressure once it exceeds a certain level. It is possible to control the tank pressure through alternative systems a safety valve.
[0000] (2) Pump: Key Parameters Associated with the Pump Include the Working Fluid Flow Rate, inlet pressure, outlet pressure, working temperature and power consumption. The flow rate of the pump is the same as that for the cryogenic tank: F l =141.0 l/h. The inlet pressure of liquid air is determined by the outlet pressure of the cryogenic tank. As a safety valve is used in the lab scale system, the pressure of the tank cannot be determined a priori. However, the cryogen pump can work over a certain range of inlet pressures at a given outlet pressure. Therefore, the inlet pressure of the pump is taken as P=0.1˜3.0 MPa. The outlet pressure of the cryogen pump is equal to the working pressure of the working fluid which is given as 20 MPa. Therefore, P 2 =20 MPa. The cryogen pump should work in the normal laboratory temperature. Therefore the working temperature is selected as 0° C.˜40° C. The temperature of the working fluid at the inlet of the pump is approximately the boiling point of liquid air (−196° C.). The temperature of the working fluid at the outlet of pump is expected to be ˜−192° C. after an adiabatic pressurisation process. The power consumed by the pump is determined by its efficiency given the outlet pressure and flow rate. If the efficiency of the pump is assumed as 0.8, the power requirement of the pump is:
[0000]
P
pump
=
F
l
·
ρ
l
·
W
1
-
2
η
p
=
1.0
kW
.
[0000] If a safe factor of 1.5 is used for the motor of the cryogen pump, the power of the motor will be 1.5 kW.
(3) Heat Exchanger: Key parameters associated with the heat exchanger include working pressures, flow rates and pressure drops of both the working fluid and the input air, and temperatures of the working fluid and input air at the inlet and outlet of the heat exchanger. The working pressure of the working fluid is approximately equal to the outlet pressure of the pump: P 2 =20 MPa. The working pressure of the input air should be close to the ambient pressure to minimise the work consumed by the blower: P 7 =P 0 . The inlet pressure of the input air is approximately equal to the pressure drop across the heat exchanger: P 6 =P Loss +P 7 The flow rate of the working fluid has been given above: F 1 =141.0 l/h=(123 kg/h). The flow rate of the input air is influenced by the performance of the heat exchanger. An approximate value is obtained by thermodynamic calculation as F 2 =206.0 kg. The pressure drop of the working fluid across the heat exchanger depends on the engineering design of the heat exchanger. It is estimated, however, to be of an order of ˜1000 Pa. The pressure drop of the input air across the heat exchanger also depends on the design. It is also estimated to be ˜1000 Pa. The temperature of the working fluid at the inlet of the heat exchanger is approximately equal to that at the outlet of the pump if the heat loss of pipes/joints/valves etc is neglected, i.e. T 2 =192° C. The temperature of the working fluid at the outlet of the heat exchanger depends on the performance of the heat exchanger, it is estimated to be close to the ambient temperature with a temperature difference assumed (i.e. 5° C.), i.e. T 3 =22° C. The temperature of the input air at the inlet of the heat exchanger is approximately the ambient temperature. The temperature of the input air at the outlet of the heat exchanger also depends on the performance of the heat exchanger; but is estimated to be close to the temperature of the working fluid at the inlet of the heat exchanger (˜−192° C.).
(4) Turbine: In analysing the performance of the turbine a multistage adiabatic expansion process with inter-heating is considered. The pressure of the working fluid at the inlet of the turbine has been given above as P 3 =20 MPa. The temperature of the working fluid at the inlet of the turbine should be close to the ambient temperature after being heated by the heat exchanger. If a temperature difference of 5° C. (below ambient) is considered, the temperature of the working fluid at the inlet of the turbine is 22° C. (ambient temperature taken as 300K): T 3 =22° C.
[0296] The number of stages is a key parameter of the turbine; more stages mean nearer isothermal operation hence more work output (see FIG. 44 ). However, more stages also mean more mechanical complexity, high pressure loss, and a high cost. A balance between the two is needed. Construction of FIG. 44 is based on the following assumptions:
[0000] Ideal Case: The pressure of the working fluid at the inlet of the turbine is 20 MPa, the efficiency of the turbine is 100%, and the temperature of the working fluid at the inlet of each stage is 27° C.
Practical Case: The pressure of the working fluid at the inlet of the turbine is 20 MPa, the efficiency of the turbine is 89%, and the temperature of the working fluid at the inlet of each stage is 22° C.
[0297] Both the ideal and practical work outputs of the turbine increase with increasing number of stages and level off between 4 to 8 stages. The total number of stages is also limited by the maximum expansion ratio of the turbine, which is normally less than 3.0. FIG. shows the expansion ratio of each stage as a function of the number of stages of the turbine. It can be seen that the expansion ratio exceeds 3 if the number of stages is less than 4. As a consequence, the number of the stages of the turbine should be more than 4. Consequently, the number of stages should lie between 4 and 8.
[0298] The pressure of the working fluid at the outlet is generally a little higher than the ambient pressure to ensure the working fluid flows smoothly. The pressure of the working fluid at the outlet is often selected as ˜0.13 MPa. If the number of stages is 6 and the temperature of the working fluid at the inlet is 22° C., the temperature of the working fluid at the outlet is approximately −44° C. Air at such a temperature can be recycled for liquid air production in large CES systems. It could also be used for industrial freezing and air conditioning in summer. The flow rate of the working fluid is equal to the flow rate of the pump: 123 kg/h (141 l/hr). Due to the low flow rate and high pressure of the working fluid, the size of the first stage of the turbine will be several millimetres, which is classified as a micro turbine.
[0000] (5) Blower: Key parameters associated with the blower are the pressure, flow rate, power and efficiency. The rated power should be approximately equal to the work output of the turbine (˜12.5 kW), and the pressure should be higher than the pressure drop of the input air across the heat exchanger.
Selection of Suitable Components
[0299] The following component selection is based on the analyses detailed above.
[0000] (1) Cryogenic tank: Product No. C404C1 (Model ZCF-2000/16) of Si-Chuan Air Separation Plant (Group) Co. Ltd is a suitable vertical type cryogenic tank having a double-walled and vacuum powder insulated structure; see FIG. 46 for a schematic diagram. This cryogenic tank has the following parameters:
Capacity=2000 litres Maximum Working pressure=1.6 MPa Empty Tank Weight=2282 kg Dimensions (Dia×H)=1712 mm×3450 mm Daily boil-off (percentage of liquid air evaporated per day at 20° C. and 0.1 MPa) <0.96%.
(2) Pump: A reciprocating piston cryogenic liquid pump is recommended for the lab scale CES experimental system and Product No. B228 of the Cryogenic Machinery Corporation (a Si-Chuan Air Separation Plant (Group) Co. Ltd company) is suitable. This pump has a high vacuum insulated pump head, which can reduce vaporisation loss and the suction pressure of pump. The piston ring and filling ring of the pump use non-metallic cryogenic material possessing good plasticity and lubricating ability. The use of special lubricant ensures that the pump can work for combustible or even explosive liquids such as liquid oxygen. The internal structure of the pump is shown in FIG. 47 . This cryogenic pump has the following parameters:
Working Fluid=Liquid air/oxygen/nitrogen/argon Inlet Pressure=0.05˜1.5 MPa Outlet Pressure=20˜35 MPa Flow rate=50˜150 l/h Power=3.0 kW Working Temperature=−10˜40° C. Weight=˜150 kg.
(3) Heat Exchanger: The heat exchanger works at a high pressure of ˜20 MPa and across a very large temperature difference (−196° C.˜27° C.). The flow rate of the working fluid is 123 kg/h. No existing products have been found that are suitable for the purpose. Therefore, a specially designed and fabricated heat exchanger is needed. Such a heat exchanger could be a tube-fin structure enclosed in a shell with the following parameters:
Working Fluid=Liquid air Heating Fluid=Ambient Air Pressure of (cold) working fluid=20 MPa Pressure of Heating Fluid=0.1 MPa Flow rate of working fluid=123 kg/h Flow rate of heating fluid=˜206 kg/h Pressure loss of working fluid=<500 Pa Pressure loss of heating fluid=<1000 Pa Working Temperature=−10˜40° C. Material of tube=304 Stainless Steel Material of fin and shell=Stainless/Aluminium Alloy Dimensions (Length/Width/Height)=2.5 m/2.2 m/0.8 m Weight=˜1200 kg.
(4) Turbine: The performance of the turbine plays a dominant role in the performance of the whole lab scale system. The output work of a turbine is normally used to drive a motor, a compressor, a fan, or a power generator. As the inlet pressure of the proposed turbine is high (˜20 MPa) and the flow rate of working fluid is low (˜123 kg/h), the turbine has to be a micro-turbine with a diameter of several millimetres. FIG. 48 shows a schematic diagram of a suitable turbine. However, no existing turbines have been found that are compatible with the proposed lab scale system. Therefore, a specially designed and fabricated turbine is needed.
(5) Blower: The blower should be able to deliver a total pressure to overcome the pressure drop of the input air. As the blower also acts as a load of the turbine, it must be rated at a total power approximately equal to the work output of the turbine (˜12.5 kW). A blower such as Beijing Dangdai Fan Company's mixed flow GXF-C (product code No. 6.5-C) is suitable. This blower has the following parameters:
Working Fluid=Air Total Pressure=1162 Pa Flow rate=24105 m 3 /h Rotary Speed=2900 rpm Noise=83 dB(A) Power=15 kW Dimensions (Length/Width/Height)=0.845 rn/0.751 m/0.800 m Weight=234 kg
(6) Other Components: As the rotary speed of the turbine is normally very high (tens of thousands of rpm), whereas the rotational speed of the proposed blower is low (2900 rpm), a transmission system is necessary for the small scale CES experimental system. In addition, to avoid icing of water (from the input air) on the wall of the heat exchanger, a drier is necessary to dehumidify the input air before it enters the heat exchanger.
[0333] Component Integration:
[0334] Liquid air from a cryogen plant is transported to the laboratory by a cryogenic truck and fed into the cryogenic tank C404C1. The reciprocating piston cryogenic liquid pump B228 pressurises the liquid air and provides kinetic energy for the working fluid to flow through the heat exchanger. The working fluid is heated in the heat exchanger by the input air provided by the blower GXF-C-6.5C, which also serves as the load of the micro-turbine in which the working fluid expands to provide power of the blower. Only a fraction of air from the blower is used as the input air.
[0000] Technological and Economical Comparisons of CES with Other Storage Systems
[0335] Currently existing energy storage systems will now be evaluated and compared with the CES. The data of the CES is calculated based on a 500 MWh storage volume and a discharge time of 8 hours. The data for other energy storage systems are mainly taken from J. Kondoh et al. “Electrical energy storage systems for energy networks” (2000, Energy Conversion & Management, vol. 41, 1863-1874), P. Denholm et al. “Life cycle energy requirements and greenhouse gas emissions from large scale energy storage systems” (2004, Energy Conversion and Management, vol. 45, 2153-2172), and F. R. Mclamon et al. “Energy storage” (1989, Annual Review of Energy, vol. 14, 241-271).
[0336] Output Power and Output Duration:
[0337] The relationship between the output power and the output duration of the storage systems is shown in FIG. 49 . Each storage system has a suitable range, and they can be classified into two types: the daily load levelling type and the electric power quality improving type.
[0338] Pumped hydro, CAES, batteries and CES are suitable to level daily load fluctuation. The superconducting magnet and flywheel with conventional bearing have a fast response and, therefore, can be utilised for the instantaneous voltage drop, flicker mitigation and short duration UPS.
[0339] Other systems such as the flywheel with levitation bearing, double-layer capacitor and redox supercapacitor are promising for small capacity energy storage and short output duration (less than 1 h).
[0340] The output power and duration of the CES is better than batteries, competitive with CAES and slightly lower than the pumped hydro. However, as discussed before, the pumped hydro requires special geographical location. Furthermore, as discussed below, pumped hydro requires a very high capital cost.
[0341] The relationship between the efficiency and the cyclic period is shown in FIG. 50 . The downwards concave curves are due to self-discharge or energy dissipation. The efficiency of the CES without superheat is lower than other energy storage systems. However, if the waste heat is recycled to superheat the working fluid in CES, its efficiency is competitive with other energy storage systems. Furthermore, the efficiency of CES with superheating increases with improvement of the air liquefaction process as discussed above.
[0342] The energy storage densities of different energy storage systems are shown in FIG. 51 . The data is based on the following:
The energy stored in a pumped hydro plant is calculated based on nigh, where m is the mass of water, g is acceleration due to gravity, and h is the effective head which is assumed to be 500 m. The cavern volume of CAES is assumed to be 54,000 m 3 at about 60 atm. The stored air allows the plant to produce 100 MW for 26 h continuously. The calculation of the energy density of CAES does not include the volume of fuel storage, motor/generator, compressor and expanders. Calculation of the energy density of the CES is based on the stored energy and the volume of the cryogen tank and heat exchangers; the volume of the motor/generator, compressor and expanders are not considered as they are at least an order of magnitude smaller than the cryogen tank. The energy density for other systems is calculated by dividing the output power by the volume of the storage device.
[0347] It can be seen that the CES and advanced secondary Na/S batteries have the highest energy densities among all systems. The energy density of the CES is higher than CAES by more than an order of magnitude and higher than pumped hydro by about two orders of magnitude.
[0348] The lifetimes of storage systems are shown in Table 3. The cycle durability of secondary batteries is not as high as other systems owing to the chemical deterioration with the operating time. Many of the components in CES are similar to those used in CAES. Therefore it is expected that the CES will have a similar life time to CAES.
[0000]
TABLE 3
Life time of the electrical energy storage systems
Systems
Years
Cycles
Pumped Hydro
40~60
Almost unlimited
CAES
20~40
Almost unlimited
CES
20~40
Almost unlimited
Lead Acid Battery
10~15
2000
Na/S battery
10~15
2000~2500
Zn/Br Battery
10
1500
Redox Flow Battery
10,000
Flywheel
>15
>20,000
Double-layer capacitor
>50,000
Redox super capacitor
5
[0349] FIG. 52 shows the relationship between the output power per unit capital cost and the storage energy capacity per unit capital cost of the compared systems. It can be seen that the CAES has the lowest capital cost per unit output power of all the systems. The capital cost of the advanced batteries (Na/S, Zn/Br, and vanadium redox flow) is slightly higher than the breakeven cost against the pumped hydro although the gap is gradually closed. The SMES and flywheel are suitable for high power and short duration applications since they are cheap on the output power basis but expensive in terms of the storage energy capacity.
[0350] In terms of the CES, the output adjusted capital cost of the CES is lower than that of the CAES because the life time of the CES is equal to that of the CAES, the initial investment of the CES is less than that of the CAES as no cavern is needed, and the energy density of the CES is higher than that of the CAES by at least an order of magnitude.
[0351] Therefore, the capital cost of the CES is lowest of all of the systems examined. In addition, the CES offers a flexibility in terms of commercial operations as products such as oxygen, nitrogen and argon can also be produced.
[0352] Construction of a pumped hydro storage system inevitably involves the destruction of trees and green land for in order to build the reservoirs. The construction of the reservoirs could also change the local ecological system which also presents environmental consequences. CAES is based on conventional gas turbine technology and involves the combustion of fossil fuel and consequently the emission of contaminates, whilst secondary batteries produce solid toxic waste.
[0353] However, CES is benign to the environment. For example, CO 2 and SO X are removed during the liquefaction process, which help with mitigating the negative environmental issues associated with the burning of fossil fuels. Undesirable airborne particulates are also removed during production of liquid air.
[0354] Therefore it can be concluded that CES has a better performance than other energy storage systems in terms of energy density, lifetime, capital cost and environmental impact. It is very competitive in comparison to other systems in terms of the output power and duration and energy efficiency. Compared with cryogenic engines for vehicles, the work output and efficiency of CES are much higher due to the use of both ‘heat’ and ‘cold’ recycles. The optimal pressure of the working fluid is 20 MPa for the CES. The optimal pressure of the input air is found to be 0.1 MPa when there is no waste heat recycled. However, when waste heat is used, the optimal input pressure could be either 0.1 MPa or 4.0 MPa. Based on an efficiency of 0.4 kWh/kg for air liquefaction, an overall efficiency of the CES operated in an ideal cycle is estimated at 0.516 for cases without using the waste heat recycle, and at 0.612 for cases using waste heat from flue gas at a temperature of 127° C. If the efficiency of the air liquefaction is taken as 0.3 kWh/kg, then the overall efficiency of the CES operated in an ideal cycle would be 0.688 for cases which do not use the waste heat recycle and at 0.816 for cases which do use the waste heat from a flue gas at a temperature of 127° C.
[0355] The specific work output and energy density of the CES depend mainly on the efficiencies of the turbine η T and the air liquefaction η A . The efficiency of the compressor can also be important if the input air is compressed. The heat exchangers play an important role in determining the overall efficiency of the cycle. A higher temperature of waste heat and a higher temperature of environment give a higher efficiency.
[0356] The CES system has a number of critical inventive steps, including the recycling of waste cold as well as waste heat. These specifically improve the overall work cycle against previous systems designed using cryogenic liquid as the working fluid.
[0357] The CES system has the potential to achieve a better performance over the existing energy storage systems in terms of energy density, lifetime, capital cost and environmental impact and is a competitive technology with respect to the output power and duration, and the energy efficiency.
[0358] The CES system has the potential to harness low grade heat and no obvious barriers to engineering. The system can be built using existing technologies for the liquefaction plant, turbine, heat exchanges, compressors, pumps, etc.
[0359] The majority of work in a CES is achieved by harnessing energy attributed to the temperature difference between the cryogen (˜77K) and the ambient (˜300K), whereas a standard geothermal or waste heat energy system can only harness temperatures above ambient (˜300K).
Sample Models of CPS Engines
[0360] Five marine engine models have been prepared using the CPS. These models are then compared against five known diesel engines. The details of the five known industrial diesel engines are shown in table 4.
[0361] CAT-3516 is a 78.1 litre 60° V-type 16-cylinder diesel engine. This engine is designed for medium transportation boats with medium speeds. CAT-3126 is a 7.2 litre turbocharged aftercooled in-line 6-cylinder engine adapted for small yachts. The ST3 engine is an air cooled diesel engine form Lister Petter company designed for narrow boats. The Cummins 6-cylinder T/C diesel engine is used by a Thames river liner suitable for public transport applications and pleasure cruising.
[0000]
TABLE 4
CAT-3516
CAT-3126
ST3
Cummins
(Caterpillar
(Caterpillar
Ford
air cooled
6-cylinder
Marine Power
Marine Power
Porbeangle
(Lister
T/C
Co Ltd)
Co Ltd)
6-cylinder
Petter)
Riverliner
Total Power
2525
bkW
261
bkW
77.6
bkW
25
bkW
522
kW
Speed
1800
rpm
2800
rpm
Working
24
days
24
hrs
10
hrs
42
hrs
24
days
Time
Heat
0
kW
0
kW
0
kW
0
kW
0
kW
Refrigeration
0
kW
0
kW
0
kW
0
kW
0
kW
Air
0
kW
0
kW
0
kW
0
kW
0
kW
Condition
Work Output
2525
kW
261
kW
77.6
kW
25
kW
522
kW
Fuel
617
litre/hr
68
litre/hr
21
litre/hr
6.9
litre/hr
128
litre/hr
Consumption
Fuel Tank
355.4
m 3
1.5
m 3
0.21
m 3
0.29
m 3
14
m 3
Volume
Tank Side
7.1
m
1.2
m
0.6
m
0.7
m
2.4
m
Length 1
Boat Speed
8.5
m/s
14
m/s
6
m/s
3
m/s
6
m/s
(~17
knots)
(~28
knots)
(~12
knots)
(~6
knots)
(~12
knots)
Cruising
17,626
km
1,210
km
~210
km
~483
km
~3,100
km
Range
1 Assuming a cubic tank.
[0362] CPS Model 1 corresponds to the CAT-3516 and is suitable for medium sized boats. As the CPS can provide a large quantity of cold, Model 1 is particularly designed for transportation of materials below sub-ambient conditions e.g. frozen meat and fish or other products. Model 1 also makes use of the cooling air and heat from the CPS for the occupants of the boat.
[0363] Models 2 to 4 correspond to the CAT-3126, the Ford Porbeagle and the Lister Petter ST3 engine and are suitable for small yachts or boats for which there is no need for large scale refrigeration, or for cool air for air conditioning. The CPS system is used to provide both propulsion and heat for use by the occupants of the boat e.g. for heating.
[0364] Model 5 corresponds to the Cummins Riverliner. The CPS system is used to provide propulsion, cooling air and heat for the boat occupants and cold for freezing foods. Only a small part (˜10%) of the cold capacity of CPS is assumed for freezing foods because the requirement for freezing food is much lower than that of model 1 for transportation of materials under sub-ambient conditions. However, a cruising range of only 60 miles (110 km) is required as the Cummins Riverliner is designed to provide 12 return journeys of 5 nautical miles per day.
[0365] The typical working conditions of all five models are P 2 =200 bar, P 1 =8 bar, T 0 =300K, η T =η COM =η p =0.88, n=1.2, γ=0.90, and T df =5.0K. The overall performance of Models 1 to 5 under these typical conditions is presented in table 5.
[0000]
TABLE 5
Model
M1
M2
M3
M4
M5
Total Power (kW)
2525
261
77.2
25
599.5
Working Time
24 days
24 hrs
10 hrs
42 hrs
5 hrs
Heat (kW)
169.6
22.0
6.5
2.1
45.2
Cold Refrigeration
962.0 1
0
0
0
51.4 2
(kW)
Cold for Air
962.0 1
0
0
0
256.8 2
Condition (kW)
Work output (kW)
1955.4
253.7
71.7
22.9
522
Energy Efficiency
59.4%
47.3%
47.3%
47.3%
52.8%
Speed (m/s)
7.8
13.9
5.9
3.0
6.0
Cruising Range (km)
16180
1198
~207
~477
110
Fuel Consumption
23264.4
3016.7
892.3
289.0
6210.5
(litre/hr)
Efficiency of
88.1%
99.0%
99.5%
98.2%
99.8%
Dissipation
Volume of Fuel (m 3 )
13400.3
73.2
9.0
12.1
31.0
Length of Side (m)
23.7
4.2
2.1
2.3
3.1
Heat transfer
5514.6
734.5
217.3
70.4
1309.3
requirement (kW)
Volume of heat
27.8
2.9
0.9
0.3
6.6
exchangers (m 3 )
Conservative
111.1
11.6
3.4
1.1
26.4
Volume (m 3 )
Length of Side (m)
4.8
2.3
1.5
1.0
3.0
1 Assuming the quantities of cold for refrigeration and air condition are the same.
2 Assuming the quantities of cold for refrigeration and ⅕ of that for air condition.
[0366] For a given boat and a given power, the cruising speed v k can be calculated by:
[0000]
P
o
=
Δ
2
3
v
k
3
C
o
[0000] where P o , Δ, v k , C o are power (work) of the engine, tonnage of the boat, cruising speed of the boat and a ship geometry related coefficient, respectively. Assuming the Model 1 CPS powered boat has the same boat body, tonnage Δ, and coefficient C o as the data used for the CAT-3516 engine, the cruising speed, v kl , is calculated using:
[0000]
ν
k
1
=
ν
k
_
3516
·
W
O
1
P
o
_
3516
3
[0000] where W O1 is the work output of model 1. The cruising range of model 1 is therefore given by C r1 =v k1 ·O t1 where O t1 is the maximum working time.
[0367] It can be seen that for the same total power, the work output of model 1 CPS for propulsion is ˜22.6% lower than that of CAT-3516, while the cruising speed and range decrease only by ˜8%. Furthermore, model 1 CPS provides ˜169.6 kW heat, 962.0 kW refrigeration cold and 962.0 kW cold for air conditioning at the same time.
[0368] Similarly, the cruising speed and range for CPS models 2 to 4 powered boat can be obtained according to the data of CAT-3126. The cruising speed and range for a CPS model 2 powered boat are:
[0000]
ν
k
2
=
ν
k
_
3126
·
W
O
2
P
o
_
3126
3
[0000] and C r2 =V k2 ·O t2 . The cruising speed and range for a CPS model 3 powered boat are:
[0000]
ν
k
3
=
ν
k
_
3126
·
W
O
3
P
o
_
3126
3
[0000] and C r3 =v k3 ·O t3 . The cruising speed and range for a CPS model 4 powered boat are:
[0000]
ν
k
4
=
ν
k
_
3126
·
W
O
4
P
o
_
3126
3
[0000] and C r4 =v k4 ·O t4 . For the same total power, the work outputs of models 2 to 4 for propulsion are ˜2.8% lower than those of the corresponding diesel engine. However, models 2 to 4 can provide 22.0 kW, 6.5 kW and 2.1 kW heat at the same time, respectively. It can be seen that the cruising speed and the range of models 2 to 4 of the CPS are ˜99.0% of those of the corresponding diesel engines.
[0369] Similarly, the cruising speed and range for a CPS model 5 powered boat can be obtained according to the data of the Riverliner. The cruising speed and range for a CPS model 5 powered boat are:
[0000]
ν
k
5
=
ν
k_Riverliner
·
W
O
5
P
o_Riverline
3
[0000] and C r5 =v k5 ·O t5 . For the same work output for propulsion, the CPS model 5 provides ˜45.2 kW heat, 256.8 kW refrigeration cold and 51.4 kW cold for air conditioning although the total power is 14.8% higher than that of the corresponding diesel engine.
[0370] The flow rate of the fuel (liquid air) can be calculated by:
[0000]
F
I
=
P
o
E
D
·
ρ
l
[0000] where F l , P o , E D , ρ l are flow rate of liquid air, power of the engine, energy density of CPS and density of liquid air, respectively. The volume of the fuel tank is expressed as:
[0000]
V
l
=
F
l
·
O
t
E
dis
[0000] where V l , O t , E dis are volume of liquid air, operation time and efficiency of heat dissipation of the tank. If a cubic tank is assumed, the length of each side, d, is
[0000]
d
=
V
I
3
.
[0371] The maximum heat transfer requirement has been analysed and estimated above. For the CPS with a unit work output (1 kW), the heat transfer requirement is: Q=2.184 kW. The size of the heat transfers exchangers for a unit work output is: V=0.011 m 3 . If a factor of safety is given as 4, the size of the heat transfer exchangers for a unit work output would be 0.044 m 3 .
[0372] On the basis of above data, a conservative estimation of the total volume of heat exchangers for models 1 to 5 CPS are listed in table 5.
[0000] Comparison of CPS with Diesel Engines
[0373] Energy Density and Price:
[0374] A comparison between tables 4 and 5 shows that the fuel consumptions of models 1 to 5 CPS are 37.70, 44.36, 42.08, 42.5 and 42.3 times those of the corresponding diesel engines respectively. Therefore, the energy densities of models 1 to 5 are 1/37.70, 1/44.36, 1/42.08, 1/42.5 and 1/42.3 of those of the corresponding diesel engines.
[0375] To compare the price of specific power of the eight engines, the price of electricity is taken as Price_e=6 pence/kWh and that of diesel as Price_d=90 pence/litre, the energy consumption to produce 1 kg of liquid air is taken as 0.4 kWh (W. F. Castle. 2002). The price of the specific power (Price_p) of the four models is calculated as: CAT-3516=22.0 p/kWh, M 1 =25.0 p/kWh, CAT-3126=23.4 p/kWh, M 2 =31.3 p/kWh, Ford Porbeagle=24.7 p/kWh, M 3 =31.3 p/kWh, Lister Petter ST3=24.8 p/kWh, M 4 =31.3 p/kWh, Cummins=22.1 p/kWh, and M 5 =28.8 p/kWh.
[0376] The price of specific power for the CPS models is comparable to the corresponding diesel models. If model 1 CPS is used for boats for transportation of frozen materials, the price of specific power would be very competitive to the counterpart diesel model.
[0377] If the energy consumption to produce 1 kg of liquid air is taken as 0.3 kWh, then the price of specific power (Price_p) for models 1 to 4 CPS become respectively 18.8, 23.4, 23.4, 23.4 and 21.6 p/kWh
[0378] Energy Efficiency:
[0379] The comparison of well-to-wheel efficiencies among the five models is shown in table 6. The CPS data is based on 0.4 kWh to produce 1 kg liquid air. It can be seen that the efficiency of model 1 CPS is similar to that of CAT-3516 and the efficiency of models 2 to 4 CPS using liquid air as fuel is lower than that of the corresponding diesel engines. The medium sized CPS boats have a higher efficiency when used for transportation of frozen materials than the small yachts do because the small yachts do not fully recover the cold. The efficiencies of CPS models 1 to 4 shown in brackets is that if the consumption of producing 1 kg liquid air is taken to be 0.3 kWh.
[0000]
TABLE 6
CAT-3126
Ford
Porbeagle
Models
CAT-
Model 1
Lister Petter
2 to 4
Cummins
Model
Model
3516
CPS
ST3
CPS
Riverliner
5 CPS
Fuel
Diesel
Liquid
Diesel
Liquid
Diesel
Liquid
Air
Air
Air
Fuel
94%
51.6%
94%
51.6%
94%
51.6%
production
(68.8%)
(68.8%)
(68.8%)
efficiency
Peak brake
38%
59.4%
38%
47.3%
38%
52.8%
engine
efficiency or
stack
efficiency
Part load
70%
70%
70%
70%
70%
70%
efficiency
factor
Transmission
85%
80%
85%
90%
85%
80%
efficiency
Weight factor
100%
100%
100%
100%
100%
100%
X Idle factor
Total cycle
21%
18%
21%
15%
21%
16%
efficiency
(24%)
(20%)
(21%)
[0380] Life Time and Capital Cost:
[0381] Since all major components of the CPS are similar to the CES, the life time of a CPS system is also estimated to be about 20 to 40 years. The life time of the diesel engines is considered to be about 17 years. However, it is believed that the life time of CPS is higher than that of diesel engines because there is no combustion process at high temperatures involved in CPS, and there is no strong friction between pistons and cylinders.
[0382] It is believed that the CPS is competitive in terms of capital cost because there is little special requirement in teens of components. In addition, a refrigeration system is made obsolete in the case of refrigeration transportation boats.
[0383] Influences of Systems on the Environment:
[0384] Diesel engines involve combustion of fossil fuels and hence lead to emission of contaminates. CPS is a totally zero emission and environmentally benign system. If liquid air is produced by renewable energy, the CPS system would be a complete ‘Green’ power system. Furthermore, contaminates can be removed during liquefaction process, which would help with mitigating the negative environmental issues associated with burning of fossil fuels. Undesirable airborne particulates can also be removed during production of liquid air.
[0385] Accordingly, Cryogenic Propulsion System (CPS) using liquid air can be used to provide combustion free and non-polluting maritime transportation. CPS has a competitive performance against the diesel engines in terms of energy price, energy efficiency, life time and capital cost and impact on the environment. CPS can have a higher efficiency if the cold energy is recovered for e.g. on-boat refrigeration and air-conditioning.
[0386] It will of course be understood that the present invention has been described by way of example, and that modifications of detail can be made within the scope of the invention as defined by the following claims.
|
The present invention concerns systems for storing energy and using the stored energy to generate electrical energy or drive a propeller ( 505 ). In particular, the present invention provides a method of storing energy comprising: providing a gaseous input, producing a cryogen from the gaseous input; storing the cryogen; expanding the cryogen; using the expanded cryogen to drive a turbine ( 320 ) and recovering cold energy from the expansion of the cryogen. The present invention also provides a cryogenic energy storage system comprising: a source of cryogen; a cryogen storage facility ( 370 ); means for expanding the cryogen; a turbine ( 320 ) capable of being driven by the expanding cryogen; and means ( 340, 350 ) for recovering cold energy released during expansion of the cryogen.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims U.S. Provisional Application, Ser. No. 61/619,041, filed on Apr. 2, 2012.
FIELD OF THE INVENTION
[0002] The present invention relates to the production of electrical energy from solar thermal energy. In particular, it relates to the collection and storage of solar thermal energy, and the subsequent production of electrical energy therefrom.
BACKGROUND OF THE INVENTION
[0003] Many systems related to thermally converting solar energy to more useful types of energy have been proposed. For example, International Patent Publication WO 81/03220 discloses such a complete system particularly directed to home use, including a Stirling engine coupled to a generator for electricity production. That system has, however, considerable disadvantages, i.a. the use of hot air and rocks as a heat conducting and storage medium, which is somewhat impractical and quite inefficient, as well as the use of a somewhat complex and inefficient system of solar collectors configured to be mounted on the roof of a house. Such a system would prove inefficient and impractical for the purpose of larger-scale power generation.
[0004] Typically, systems suitable for larger-scale power generation employ more advanced solar collectors using some type of parabolic reflector, as is e.g. disclosed in U.S. Pat. No. 4,335,578. However, the dish-type reflector shown in U.S. Pat. No. 4,335,578 is highly susceptible to wind influence since it is mounted high above the ground, difficult to keep clean and thus operate efficiently, and additionally expensive to produce. The high wind susceptibility means that the system cannot operate at greater wind strengths, since the collector must then be aligned horizontally to avoid damage. The heat absorption and transport method employed by this system is moreover quite complicated, using two different fluids, state changes of these fluids, heat exchangers etc., thus making the system expensive to produce and maintain. However, U.S. Pat. No. 4,335,578 features a detailed discussion of the suitability of various fluids as heat conducting and storage medium, showing that e.g. molten salt has a high potential for use as such a fluid.
[0005] More modern systems, such as that disclosed in US patent application 2006/0225729 A1, attempt to avoid the high wind susceptibility of dish-type solar collectors by the use of smaller trough-type collectors that typically have a pipe or the like at the line of focus of the trough, through which the heat conducting and storage fluid can flow. Such devices can be mounted much closer to the ground. However, they also have significant disadvantages. The troughs tend to act as dirt collectors, greatly reducing their efficiency, unless they are covered by some kind of transparent covering that also reduces their efficiency. Moreover, due to their linear layout, such systems can only track the sun around one axis, reducing their general efficiency.
[0006] Some of the disadvantages associated with the use of parabolic reflectors (whether of dish- or trough-type) as solar collectors can be overcome by the use of Fresnel lenses instead, as is e.g. disclosed in U.S. Pat. No. 6,775,982 B1. However, the power requirements of the Stirling engine disclosed therein lead to the use of very large Fresnel lenses of e.g. 20 m diameter. Such large Fresnel lenses are nevertheless quite heavy and expensive and must be mounted high above the ground due to their substantial focal length, once again resulting in a high susceptibility to wind influence.
[0007] Moreover, the power transfer from the Fresnel lenses to the Stirling engine by means of light guiding fibers, as disclosed in U.S. Pat. No. 6,775,982 B1, requires considerable further refinement, since directly heating a Stirling engine by means of light guiding fibers will destroy the engine due to the high temperatures achieved (approximately 2000° C. while typical operating temperatures of Stirling engines are 700-1000° C.).
BRIEF SUMMARY OF THE INVENTION
[0008] It is, therefore, an object of the present invention to provide an improved solar collector apparatus. This apparatus comprises an array of Fresnel lenses arranged in rows, the Fresnel lenses having a focal length, and energy absorption devices located below each of the Fresnel lenses at a distance substantially corresponding to their focal length, wherein the array is mounted on arms at a height above ground substantially corresponding to the focal length of the Fresnel lenses, wherein the rows of said array of Fresnel lenses are configured such that they are rotatable about a lengthwise horizontal axis of said rows, wherein means are provided for rotating the rows of Fresnel lenses about their lengthwise axis, and wherein the array of Fresnel lenses is rotatable about a vertical axis. Thus, the collector apparatus can be mounted low above the ground, since it comprises multiple smaller Fresnel lenses that can have relatively short focal lengths. The configuration achieved enables effective two-axis sun tracking.
[0009] In one embodiment, the Fresnel lenses are substantially square shaped, which enables them to be arranged more efficiently and lowers production costs.
[0010] In a further embodiment, each row of Fresnel lenses has an automatic wipe-cleaning system. Thus, they can be kept clean, ensuring continued operation of the solar collector apparatus at high efficiency.
[0011] In another embodiment, the array of Fresnel lenses is mounted on a base rotatable about a vertical axis, the rotatable base forming an insulated lid of a storage tank for a heat conduction and storage fluid. Thus, the distance between the heat conduction and storage fluid and the means for heating the fluid is minimised.
[0012] In a preferred embodiment, each energy absorption device comprises a heat conductor, a transparent plate mounted above the heat conductor, and an insulated casing surrounding the heat conductor where it is not covered by the transparent plate, wherein both the heat conductor and the transparent plate have the shape of a segment of a circle having a center located above the transparent plate, wherein the heat conductor extends into a heat conduction and storage fluid through an opening in the insulated casing, a part of the heat conductor submerged in the heat conduction and storage fluid being substantially gill-shaped.
[0013] In another preferred embodiment, each energy absorption device comprises a light guiding fiber (or alternatively a bundle of light guiding fibers) having an end, means for adjusting the position of the end of the light guiding fiber, and a casing surrounding the light guiding fiber and the means for adjusting the position of its end, wherein the upper side of the casing is formed by a transparent plate having the shape of a segment of a circle having a center located above the transparent plate, wherein the light guiding fiber extends to a heat conduction and storage medium through an opening in the casing. A diverging lens may be mounted adjacent to the end of the light guiding fiber to adjust the acceptance angle. Thus, modular energy absorption devices are provided, which can absorb heat from the focus of the Fresnel lenses and transfer this heat to the heat conduction and storage medium.
[0014] In further embodiments, each energy absorption device additionally comprises an automatic wipe-cleaning system for the transparent plate. Thus, they can be kept clean, ensuring continued operation of the solar collector apparatus at high efficiency.
[0015] In another embodiment, the means for rotating the rows of Fresnel lenses about their lengthwise axis are linked to the means for adjusting the position of the end of the light guiding fiber in those energy absorption devices comprising such a fiber. Thus, the solar tracking of the rows of Fresnel lenses is linked to the positioning of the light guiding fibers, ensuring that they always remain in the focal region of the corresponding Fresnel lenses.
[0016] In a second aspect, it is an object of the invention to provide an improved system for solar energy collection and electricity production. This system comprises a solar collector apparatus as provided above, a thermal storage system having a thermal energy conduction and storage medium, at least one means of transforming thermal energy into electric energy, means connecting the solar collector apparatus with the thermal storage system, means connecting the thermal storage system with the at least one means for transforming thermal energy into electrical energy, wherein the solar collection apparatus heats the thermal energy conduction and storage medium via the corresponding means, and wherein the thermal energy conduction and storage medium supplies the at least one means for transforming thermal energy into electrical energy with thermal energy via the corresponding means. Thus, a complete and efficient system for producing electrical energy from solar thermal energy is provided. The system can directly convert thermal energy to electrical energy using e.g. thermoelectric generators (based on the Seebeck effect).
[0017] In a preferred embodiment, the means for transforming thermal energy into electrical energy comprise a heat engine employing a thermodynamic cycle coupled to a means for generating electrical energy from mechanical energy.
[0018] In a particularly preferred embodiment, the heat engine is a Stirling engine.
[0019] In one embodiment, the thermal storage system has at least one insulated storage tank containing the heat conduction and storage medium, said medium being a solid.
[0020] In another embodiment, the heat conduction and storage medium is a fluid, and the thermal storage system has at least one insulated storage tank containing said fluid.
[0021] In a preferred embodiment, the heat conduction and storage solid is graphite, while in another preferred embodiment, the heat conduction and storage fluid is molten salt. Both graphite and molten salt have proven to be very effective heat conduction and storage media in the temperature range generally achieved by solar thermal systems.
[0022] In further embodiments, the system for solar energy collection and electricity production comprises means for exchanging said at least one insulated storage tank, wherein the insulated storage tank is configured to be transportable.
[0023] In a further embodiment, the means connecting the solar collector apparatus with the thermal storage system are configured such that the at least one insulated storage tank is heated from below.
[0024] In a further embodiment, the means connecting the thermal storage system with the at least one heat engine are configured such that heat is transferred from the top of the at least one insulated storage tank to the at least one heat engine. Thereby, efficient heat transfer is ensured within the insulated storage tank, using conduction in solid storage media and convection in fluid storage media.
[0025] In another embodiment, the system for solar energy collection and electricity production additionally comprises embedded controllers using real-time algorithms, said algorithms being able to consider weather forecast data. Thus, smart and automatic, on-the-fly management of the system is provided, and weather forecasts can be considered.
[0026] This aim is achieved by the inventions as claimed in the independent claims. Advantageous embodiments are described in the dependent claims.
[0027] Even if no multiple back-referenced claims are drawn, all reasonable combinations of the features in the claims shall be disclosed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0028] Other objects and advantages of the present invention may be ascertained from a reading of the specification and appended claims in conjunction with the drawings therein.
[0029] For a more complete understanding of the present invention, reference is established to the following description made in connection with accompanying drawings in which:
[0030] FIG. 1 compares a Fresnel lens to a conventional lens;
[0031] FIG. 2 shows a typical example of an industrial application;
[0032] FIG. 3 illustrates how an array of Fresnel lenses replaces a single one;
[0033] FIG. 4 shows an array of Fresnel lenses replacing a single one;
[0034] FIG. 5 shows a top view of the horizontal and vertical axis sun tracking;
[0035] FIG. 6 shows a side view of the vertical axis sun tracking;
[0036] FIG. 7 shows a side view of an insulated capturing socket with embedded heat conductor;
[0037] FIG. 8 shows a top view of an insulated capturing socket with embedded heat conductor;
[0038] FIG. 9 shows an insulated capturing socket with a light guiding fiber in the lower position;
[0039] FIG. 10 shows an insulated capturing socket with a light guiding fiber in the upper position;
[0040] FIG. 11 shows a front view of two insulated capturing sockets with light guiding fibers;
[0041] FIG. 12 shows the conductor gills for conductive heating of the molten salt;
[0042] FIG. 13 shows a side view of a storage tank;
[0043] FIG. 14 shows a side view of the layout of a transportable storage tank;
[0044] FIG. 15 shows a top view of a large IRB with two embedded transportable storage tanks;
[0045] FIG. 16 shows a timed Kripke-structure;
[0046] FIG. 17 shows basic JCTL operators; and
[0047] FIG. 18 shows a star topology interconnection of storage tanks.
DETAILED DESCRIPTION
Technical Solutions
[0048] Ground Placement of the Heat Engine
[0049] Systems using parabolic reflectors have a focal point F, where the Stirling engine is placed, situated high above the ground, resulting in many serious disadvantages:
[0050] Susceptibility to wind forces requires the systems to interrupt their operation at high wind speeds and move into a horizontal position until wind speed decreases.
[0051] The systems can not benefit from storage of thermal energy.
[0052] Expensive heavy-duty construction is required.
[0053] A high amount of smaller, lighter Stirling engines is required, which significantly increases the overall and maintenance cost.
[0054] Further high maintenance costs (e.g. cleaning) are incurred.
[0000] In order to keep a heat engine close to the ground, the point F must be lowered, which can be achieved using optical lenses instead of parabolic reflectors.
[0055] Designing a Solar Heat Producing System Using Optical Lenses
[0056] Low weight
Some of the largest Stirling engines commercially produced deliver approximately 40 kW. The Earth receives 1.413-1.321 W/m 2 of solar irradiation (1 W/m 2 assumed for simplicity). At a typical 30% efficiency, such an engine needs approx. 133 kW of solar irradiation, requiring a lens area of 133 m 2 , i.e. a diameter of approximately 13 m. Both the weight and the cost of such a lens would be immense.
[0058] To overcome both problems at once, we use Fresnel lenses 10 instead of regular optical lenses 20 ( FIG. 1 ). Fresnel lenses feature large apertures and short focal lengths without the mass and volume required by lenses of conventional design. Fresnel lenses available commercially at low cost are often made of PVC in a quadratic shape.
[0059] Placement Low Above the Ground
Covering an area of 133 m 2 would require a Fresnel lens with a size of approx. 11.5 m×11.5 m. Even made of PVC, such a lens would still have a significant weight and cost. Furthermore, the focal length ƒ of such a large lens requires an installation at a significant height above the ground. FIG. 2 shows a typical example 50 of an industrial application, which is very susceptible to wind forces. To solve this problem, we introduce a system comprising an array (or matrix) of Fresnel lenses instead of a single one, as shown in FIG. 3 . The array of smaller Fresnel lenses 110 covers the same total area as the single large one 100 , but the focal length ƒ m of a smaller lens 110 in the array is significantly shorter than the focal length ƒ s of the single lens 100 , as shown in FIG. 4 . Thus, the array allows us to install the solar capturing system very low above the ground.
[0063] Supplying Large Stirling Engines at Low Cost
We consider large Stirling engines in order to minimize installation and maintenance costs. As an example, we consider an area of 144 m 2 supplying a Stirling engine with 144 kW of heat. An engine with a typical 30% efficiency would deliver approximately 43.2 kW of power. We implement a 12 m×12 m solar capturing array (SCA), consisting of 144 single Fresnel lenses with a size of only 1 m×1 m=1 m 2 each. Such Fresnel lenses are widely commercially produced, meaning that the total cost of such an array can be kept very low.
[0065] Cleaning and Maintenance
Due to their shapes (dishes or troughs), most collector systems also act as collectors for dust and dirt. A dirty reflector surface significantly reduces the performance of the system, requiring frequent interruptions for cleaning and maintenance. Due to its flat surfaces, on the other hand, our system is very easy to clean. This can be performed by an automatic cleaning system, which features a wiper on each single row of lenses of the array.
[0067] Performing Two-Axis Sun-Tracking
[0068] In order to perform sun tracking at the horizontal axis, we introduce a rotatable base 170 , on which the solar capturing array (SCA) 150 is mounted. The entire system is placed on circular rails 180 allowing its rotation (see FIG. 5 ). Four or more arms 160 keep the SCA at a height of ƒ m above the level of the rails ( FIG. 6 ).
[0069] In order to perform sun tracking at the vertical axis, we divide the SCA into rows of lenses, separating all rows from each other and putting them into their own separate frames. Each frame features a central longitudinal axis 210 and is mounted separately on a main external frame 200 , which is installed on arms 160 , as shown in FIG. 5 . A vertical movement is then allowed for each row by means of its central axis 210 , as shown in FIG. 6 .
[0070] Minimizing the Area Required to Avoid Shading
[0071] In our approach the area required to keep the solar collectors from shading each other is minimized. The solar capturing array rotates entire rows of Fresnel lenses in the x-axis (horizontal). Hence, it allows the absence of any distance between the single Fresnel lenses of each row.
[0072] As shown in FIG. 6 , only a distance δ between the rows is required and must be chosen correctly, in order to allow the shadow-free operation of the system, as the rows perform their vertical movement (in the y-axis).
[0073] Capturing of Focused Solar Energy
[0074] In order to prevent energy loss, the rotatable base must have very good thermal insulation. The solar energy delivered by the SCA can be captured in two different ways.
[0075] a. Capturing of Focused Solar Energy by Means of Heat Conductors
For this purpose, the IRB features modular insulated capturing sockets (ICSs) underneath each Fresnel lens of the SCA, as shown in FIGS. 7 and 8 . Each of the insulated capturing sockets (ICSs) 270 contains a heat conductor 280 that captures the focused solar energy delivered by the Fresnel lens 10 placed above it. The heat conductors have the shape of segmental arches on their upper sides, in order to maintain the lenses of the SCA continuously focused during sun tracking. Each ICS features also a curved transparent plate 260 mounted above the heat conductor, which guarantees its thermal insulation on the upper side and simultaneously avoids dirt entrance. The transparent plates also have the shape of segmental arches like the heat conductors, in order to maintain equal light refraction at different vertical angles of the Fresnel lenses. Furthermore, each ICS Features an Automatic Wipe-Cleaning System for its Curved Transparent Plate
[0081] b. Capturing of Focused Solar Energy by Means of Light Guiding Fibers
For this purpose, special insulated capturing sockets (ICSs), as shown in FIGS. 9 , 10 and 11 , are employed. The IRB features a thermally insulated bottom 340 and forms a sealed insulated box, which encloses all necessary parts of the system, in order to prevent energy losses, but also to protect from dirt. Each ICS 270 is mounted on the top of the IRB 335 and encloses the fiber tracking box, one end of a light guiding fiber 325 , a fiber guiding wheel 345 and a curved transparent plate 260 for thermal insulation and dirt protection. The horizontal tracking is performed by the rotating movement of the IRB. The drive for the vertical tracking is enclosed in the vertical tracking drive box 360 . There, the motor 355 drives the transmission chains 350 in order to perform a simultaneous tracking for the Fresnel lenses 10 and for the light guiding fibers 325 . The fiber tracking box encloses the vertical tracking gearwheel 300 , the fiber tracking gearwheel 310 , the guide chain 315 and the fiber guiding socket 320 . The fiber guiding socket 320 surrounds the light guiding fiber 325 and performs a circular motion, which enables the tracking of the focus. For this purpose, the fiber tracking box features slide grooves 330 as guides for the circular motion of the fiber guiding socket 320 . The fiber guiding socket 320 features appropriate slide wings that slide along the slide grooves 330 . The fiber guiding socket 320 has at its lower end the shape of a horn, in order to enable a smooth guidance of the light guiding fiber 325 and prevent its sharp edging or folding. The drive for the circular motion of the fiber guiding socket 320 is performed by a guide chain 315 . In order to remain on track, the diameter of the vertical tracking gearwheels 300 must have the correct ratio to the diameter of the gearwheel 305 for the row of lenses. According to this ratio, the fiber guiding socket 320 moves with the correct angular velocity, in order to follow the rotation of the Fresnel lens 10 above it. A major advantage of the ICSs is their good insulation from the environment. Each ICS operates as a sealed box, avoiding thermal losses and dirt entrance. There is no contact between the Fresnel lenses 10 and the light guiding fibers 325 . The drive for the tracking of all foci of an entire row of Fresnel lenses is performed by means of a single vertical tracking axis 210 only. Each light guiding fiber 325 is passed between the top and the bottom of the IRB over a fiber guiding wheel 345 , which prevents sharp edging or folding. Furthermore, each ICS 270 features an automatic wipe-cleaning system for its curved transparent plate 260 .
[0091] Thermal Storage System
[0092] The IRB is capable of transferring all energy delivered by the SCA to a thermal storage system. Such a system allows operation of a solar thermal plant also in bad weather or at night. One of the most established methods for retaining collected thermal energy is the storage in molten salt. Alternatively, a solid medium, e.g. graphite, can be used. Both materials can be kept in storage tanks, which are so well insulated that the thermal energy can be usefully stored for up to two months.
[0093] The system presented here can preferably use molten salt or graphite to transfer heat and supply a heat engine, while simultaneously benefitting from an embedded thermal storage system. The main idea is not to heat a thermodynamic engine directly, but to first heat a storage medium, which supplies the heat engines with energy. The storage medium can be heated by conduction or by means of light guiding fibers.
[0094] i. Heating Molten Salt by Conduction
In order to minimize moving parts for the energy transfer, we place a main thermal storage tank directly underneath the insulated rotatable base (IRB). In order to prevent energy loss, the IRB must have very good thermal insulation. The main storage tank can also be placed into the ground. The IRB here forms a sealed (but rotating) cover of the thermal storage tank. Each lower end of an ICS-heat conductor features gills 410 , which are immersed into the salt 400 , as shown in FIG. 12 .
[0097] ii. Heating Molten Salt or Graphite by Means of Light Guiding Fibers
In this case, the IRB features a thermally insulated bottom (shown in FIGS. 9 to 11 ) and does not form the cover of the storage tank, which is separately sealed. The light guiding fibers can guide the energy to several storage tanks. A storage tank can feature short light guiding fibers embedded in its bottom, and thus can guide heat to the storage medium from below, as shown in FIG. 13 . The embedded light guiding fibers are coupled to longer ones that lead the solar energy from the IRB and forward the energy into the storage tank. Considering molten salt as storage medium, the storage tank design takes advantage of convection principles and thus allows the heating of molten salt, and also the operation of heat engines, without the use of a pump. The design is shown in FIG. 13 . We lead the solar energy underneath the storage tank by means of light guiding fibers 325 and heat the molten salt 400 from these lowest points, causing movement of the fluid due to convection. The heated molten salt flows to the top of the storage tank, leaving molten salt with a lower temperature at the bottom. The colder molten salt is thus heated by the light guiding fibers. The movement continues until the lower, colder side reaches similar temperatures to those of the upper, hotter side. Stirling engines 450 can be mounted 430 on top of the storage tank. They absorb great amounts of heat for their operation, causing a substantial cooling of the molten salt. Hence, we obtain colder molten salt above the bulk of the storage tank, which results in a further movement of the hotter fluid towards the Stirling engines. The cooled molten salt flows to the bottom of the storage tank. Considering graphite as storage medium, the storage tank design takes advantage of conduction principles and thus allows the heating of graphite, and also the operation of heat engines, without the use of mechanical parts. Stirling engines 450 can also be mounted 430 on top of the storage tank. They absorb great amounts of heat for their operation, causing a substantial cooling of the upper graphite side, hence causing a heat transfer from the hotter lower side to the colder upper side.
[0104] Transferring Solar Energy Without an Electricity Network
[0105] In most cases, thermal energy can be usefully stored in insulated tanks for up to two months. Therefore, the apparatus presented in this invention also features a mounting system which enables the connecting and disconnecting of the above presented storage tanks. Hence, it also enables the transfer of entire storage tanks to a desired location, where they can be used for electricity production, e.g. by means of Stirling engines, turbines or the like. The electricity production thus need not occur in the same location as the solar energy collection.
[0106] Consider FIG. 14 : The connecting and disconnecting part of the system consists of a structure 470 , under which one or more storage tanks can be placed in order to be connected to Stirling engines 450 and to light guiding fibers. The structure features a ceiling, on which Stirling engines 450 are mounted. The light guiding fibers lead to the bottom of the structure 470 , as shown in FIG. 14 . There, they are coupled to short light guiding fibers 325 embedded into the bottom of the storage tanks (see FIG. 14 ) to guide the solar energy into the storage tank. One side of the structure features an opening mechanism to allow the entrance or exit of one or more storage tanks.
[0107] Graphite blocks, but also established molten salts such as FLiNaK or FLiBe might require very large solar capturing arrays, in order to cope with their high heat storage capacities.
[0108] In such a case, it is preferred to consider embedding one or more transportable storage tanks 480 in a large IRB 170 , as shown in FIG. 15 . For this purpose, the IRB is placed on multiple circular rails 180 and features several arms 160 in order to achieve a better static behavior. The energy is transferred directly underneath the storage tanks 480 by means of light guiding fibers. The storage tanks 480 follow the rotation of the IRB 170 . For this purpose they move on their own circular rails 490 . The design allows mounting and unmounting of transportable storage tanks.
[0109] Extending Annual Operation of Solar Thermal Power Plants
[0110] This chapter refers to solar power plants with non-transportable heat storage tanks, thus having limited storage capabilities.
[0111] a. Very Low Material Expenses
A solar energy system without any storage tanks is only able to operate if it receives enough solar irradiation. For such a system, we have Annual Operation Hours≦Annual Sunshine Hours For longer operating hours, we must therefore equip the system with energy capturing capabilities that exceed its maximum energy consumption, and capabilities for storing superfluous captured energy. Thus, operating a system with storage tanks requires a significant increase of the solar energy capturing surface. On the other hand, this increase strongly depends on the annual solar irradiation hours at the location of the system. Compared to a System Without Storage Capabilities, the Additional Investment in a Solar Power Plant Featuring Thermal Storage Involves
[0117] i. a significantly increased amount of solar energy capturing devices, in order to cover the required additional capturing surface;
[0118] ii. heat storage tanks with enough capacity for the superfluous captured energy; and
[0119] iii. additional land.
[0120] The system presented in this invention merely requires additional Fresnel lenses and their frames, insulated capturing sockets (ICSs), and heat conductors or light guiding fibers, in order to increase its solar energy capturing surface. All of these parts consist of commonly used materials and can be purchased or manufactured at very low cost.
[0121] b. Smart Management of Storage Tanks
[0122] Investments in energy storage systems are basically focusing on two main targets:
[0123] In periods of good weather and daylight, store as much energy as possible, while simultaneously operating the system at maximum capacity.
[0124] In periods of bad weather or darkness, enable as much operation as possible.
[0125] However, if we consider power plants with non-transportable storage tanks, their capacity is limited and can usually handle a fixed amount of energy. Moreover, it is very difficult in practice to store heat during the summer months in order to use it in the winter. In most cases, thermal energy can only be usefully stored for up to two months. Thus, capacity problems would occur:
[0126] In long periods of good weather, a continued storage of captured energy would most likely exceed the capacity of the storage tanks.
[0127] In long periods of bad weather, the captured energy would not be sufficient, for example to keep molten salt liquid. This could destroy the plant.
[0128] Consequently, known applications only feature very limited heat storage capabilities that cover up to a few hours of extended operation.
[0129] In order to overcome these problems, the system presented in this invention features
[0130] I. a set of simultaneously operating heat engines,
[0131] II. a set of interconnected storage tanks, and
[0132] III. embedded controllers that feature real-time algorithms, performing smart management of the system on-the-fly.
[0133] The invention consumes the total captured solar energy for electricity production and allows nearly non-stop operation of at least a subset of its heat engines.
[0134] Two practical limitations must be confronted:
[0135] a. The capacity of storage tanks is limited.
[0136] b. Thermal energy can only be stored for up to two months.
[0137] One or more embedded controllers featuring real-time algorithms supervise the system and all its parameters and perform on-the-fly smart management of the energy amounts. A main advantage of these real-time controllers is their ability to consider weather forecasts.
[0138] The controllers feature real-time formal methods, in order to obtain mathematical proof of the fulfillment of the requirements of the system. This is performed in 3 steps.
[0139] In the first step, the controller models the entire solar thermal plant as a real-time system: :=
[0000] where
is a set of heat engines
[0140] is a set of interconnected storage tanks
[0141] is a set of solar capturing matrices
[0142] is the total capturing surface of the plant
[0143] is the total storage capacity of the plant
[0144] θ is the temperature of the storage medium
[0145] is a set of evaluable weather forecast parameters
[0146] In the second step, the controller transforms the model into a timed Kripke-structure (see Logothetis, G.: “Specification, Modelling, Verification and Runtime Analysis of Real Time Systems”, chapter 3.1). An example of a timed Kripke-structure is shown in FIG. 16 .
[0147] The main characteristics of a timed Kripke-structure are as follows:
[0148] It is a discrete time model.
[0149] It has a finite number of states.
[0150] Its paths are infinite and represent the system's behavior.
[0151] Each transition consumes one or more units of time.
[0152] The choice of transition is non-deterministic.
[0153] Formulae represent the system's properties at any given state.
[0154] Labeled edges represent timed actions.
[0155] Examples for formulae:
[0156] p:=temperature of 5th auxiliary storage tank is 532.5° C.
[0157] q:=27% brollability according to weather forecasts
[0158] Examples for transitions:
[0159] brollability will change from 23% to 31% within 55 hours, according to weather forecasts
[0160] 2nd auxiliary storage tank will reach its maximum heat capacity after 17 hours
[0161] Timed Kripke structures representing real-time systems often have more than 10 200 states.
[0162] In the third step, the controller applies JCTL algorithms. JCTL (see Logothetis, G.: “Specification, Modelling, Verification and Runtime Analysis of Real Time Systems”, chapter 3.2) is a branching-time temporal logic which considers real-time systems modeled as timed Kripke-structures (see FIG. 17 ). JCTL has the following properties:
[0163] JCTL uses modal operators, path quantors and time-constraints.
[0164] JCTL formulae exactly describe the specifications of a system.
[0165] JCTL algorithms explore the entire state space to verify JCTL formulae.
[0166] Thus, we proceed as follows:
[0167] The controller uses JCTL formulae to describe the required specifications of a system in order to ensure non-stop operation.
[0168] Then, JCTL algorithms are applied, in order to explore the entire state space to obtain mathematical proof for the existence of paths that satisfy the required specifications.
[0169] Once found, the controller traces at least one of these paths.
[0170] The system follows the actions of the traced path.
[0171] If no such path exists, the controller automatically considers the next less tight constraint and starts examining it, and so on.
[0172] Example: Verify the existence of paths, such that the temperature of the 2nd, 5th and 7th storage tanks will stay above 617.3° C. for at least 48 hours.
[0173] Implementing Power Plants
[0174] This chapter refers to solar power plants with non-transportable heat storage tanks, thus having limited storage capabilities.
[0175] a. Definitions
The consuming surface S cons is the minimum solar capturing surface required by one heat engine of the plant in order to operate at maximum power. Focusing on non-stop operation, we consider the required increase of the capturing surface. This increase strongly depends on the annual hours of solar irradiation at the location of the plant. The storing surface S stor is the minimum solar capturing surface required for collecting within a period of one year an amount of energy that would enable the true non-stop operation of one heat engine for one year at its specific location. The increase factor φ inc is the ratio S stor /S cons, indicating the surface increase required for true non-stop operation according to the solar irradiation at the location of the plant. For example, in a location with an average of 2,200 hours of solar irradiation, non-stop operation would require increasing S cons by a factor of φ inc ≅4 (8,760/2,200), i.e. S stor ≅4·S cons . The surface multiplier λ∈{×∈ ×≧1 (┌ φinc┐·×)∈ } determines optimized sizes of the capturing surface related to the number of heat engines.
[0182] The non-stop surface-requirement S nst :=λ·S stor ·(┌φ┐/φ inc ) is the minimum capturing surface required in order to achieve true non-stop operation of at least λ heat engines.
[0183] The non-stop engine requirement ε nst :=λ·┌φ inc ┐ is the minimum number of heat engines required in order to achieve nearly non-stop operation of at least λ of them.
[0184] b. Example
We consider a system, comprising a set of ε nst heat engines, a set of ε nst /λ solar capturing arrays (SCAs), each with a surface of (λ·S nst )/ε nst , a set of ε nst /λ IRBs, each carrying A heat engines a main storage tank (heat engines mounted above it are main engines), a set of auxiliary storage tanks (heat engines mounted above them are auxiliary engines), and one or more embedded real-time controllers.
[0192] FIG. 18 shows a very simplified implementation of the above, where λ=1 and ε nst =4: One main and three auxiliary storage tanks are used.
[0193] 1. The main storage tank 500 is kept as small as possible in order to maintain the optimal operating temperature, but also to achieve quick heating of the tank contents after a long period of bad weather. The auxiliary storage tanks 510 are all directly connected to the main tank in a star topology.
[0194] 2. Each heat engine is supplied with energy from the storage tank underneath the IRB it is mounted above.
[0195] 3. All solar capturing arrays (SCAs) send their energy directly to the main storage tank.
[0196] 4. A total surface of S nst supplies the main storage tank with energy. This capturing surface would allow a true non-stop operation of λ heat engines.
[0197] 5. In long periods of good weather, the main heat engines cannot convert all the captured heat into electricity. When the capacity of the main storage tank is exceeded, the controllers decide as follows:
a. If the temperature of at least one auxiliary tank is suitable for the operation of its heat engines, then, depending on the weather forecast,
i. allow operation of some auxiliary heat engines; or ii. allow heat exchange from the main storage tank to some auxiliary tanks, in order to store the entire energy; or iii. allow both of the above;
b. else (none of the auxiliary tanks has sufficient temperature for operation of its heat engines), depending on the weather forecast,
i. allow heat exchange from the main storage tank to one auxiliary tank only, in order to increase its temperature; or ii. allow heat exchange from the main storage tank to more than one auxiliary tank.
[0205] 6. If the capacity of one or more auxiliary tanks is also reached, the controllers decide according to the weather forecast in an analogous way, as for the main storage tank.
[0206] 7. If the capacity of all storage tanks is reached, the controllers allow the operation of all heat engines. Thus, loss of captured solar energy is avoided. In particular, if S plant is the total capturing surface of the entire plant, we have
[0000] S plant =((λ· S nst )/ε nst )·(ε nst /λ)= S nst
[0000] S plant =λ·S stor ·(┌φ inc┐ /φ inc
[0000] S plant =λ·φ inc ·S cons ·(┌φ inc ┐/φ inc )
[0000] S plant =λ·┌φ inc ┐·S cons
[0000] S plant =ε nst ·S cons
[0000] The total captured energy of the plant does not exceed the maximum energy consumption of all heat engines. Thus, if all engines are running, all captured energy is consumed for electricity production.
[0207] 8. In long periods of bad weather, the controller first decides the number of heat engines that are allowed to operate. For this purpose, the consideration of weather forecasts is essential:
a. Operating too many heat engines will consume the stored energy too quickly. This might lead to low salt temperatures if the bad weather continues. b. Operating a lower number of engines might lead to insufficient electricity production, if the duration of the bad weather is foreseeable.
[0210] 9. As the temperature of the storage tanks decreases, the controller decides on the basis of weather forecasts,
a. to stop the operation of some heat engines; or b. to interrupt the heat exchange between the main tank and some of the auxiliary tanks; or c. to perform both of the above.
[0214] 10. Interruption of the heat exchange between an auxiliary tank and the main tank takes place at a storage medium temperature T int . In case of molten salt, T int must be higher than the melting point of the salt used. In case of graphite, T int must be high enough to ensure the further operation of the power plant. The controller selects the optimal T int based on weather forecasts.
[0215] 11. In a worst-case scenario the system allows the use of external energy sources in order to always keep the temperature of a chosen salt above melting point.
[0216] While the present inventions have been described and illustrated in conjunction with a number of specific embodiments, those skilled in the art will appreciate that variations and modifications may be made without departing from the principles of the inventions as herein illustrated, as described and claimed. The present inventions may be embodied in other specific forms without departing from their spirit or essential characteristics. The described embodiments are considered in all respects to be illustrative and not restrictive. The scope of the inventions is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalence of the claims are to be embraced within their scope.
REFERENCES
[0000]
20 Fresnel lens
20 conventional optical lens
50 industrial application of prior art system
100 single large Fresnel lens
110 array of Fresnel lenses
150 solar capturing array (SCA)
160 arm
170 insulated rotatable base (IRB)
180 circular rails
200 frame
210 vertical tracking axis
250 vertical tracking
260 curved transparent plate
270 insulated capturing socket (ICS)
280 heat conductor
300 vertical tracking gearwheel
305 lens row gearwheel
310 fiber tracking gearwheel
315 guide chain
320 fiber guiding socket
325 light guiding fiber
330 slide grooves
335 top of IRB
340 bottom of IRB
345 fiber guiding wheel
350 transmission chain
355 vertical tracking motor
360 vertical tracking drive box
400 thermal storage medium, e.g. molten salt
410 heat conductor gills
430 mounting for Stirling engine
450 Stirling engine
470 structure for connecting to portable storage tank
480 portable storage tank
490 rails supporting storage tank
500 main storage tank
510 auxiliary storage tank
REFERENCE CITED
Patent Literature
[0254] U.S. Pat. No. 4,335,578
[0255] U.S. Pat. No. 6,775,982 B1
[0256] US 2006/0225729 A1
[0257] WO 81/03220
Non-Patent Literature
[0258] Logothetis, G.: “Specification, Modelling, Verification and Runtime Analysis of Real Time Systems”. Vol. 280 of Dissertations in Artificial Intelligence, IOS Press 2004, ISBN 978-1-58603-413-9
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We present an improved system for solar energy collection and electricity generation, comprising a solar collector apparatus, said apparatus comprising an array of square Fresnel lenses arranged in rows with modular energy absorption devices located below, wherein the array is mounted on arms at a low height above ground, the rows of said array are rotatable horizontally about their lengthwise axis, and the array is mounted on a rotatable base
The system further comprises transportable insulated storage tanks containing a storage medium, Stirling engines and generators. The solar collection apparatus heats the storage medium, the storage medium supplies the Stirling engines with heat, and each engine is coupled to a generator.
In a preferred embodiment, the system additionally comprises embedded controllers using real-time algorithms providing smart on-the-fly management of the system.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional application of U.S. patent application Ser. No. 12/439,266 filed Feb. 27, 2009, which is the national stage application of International Application No. PCT/US06/35137 filed 12 Sep. 2006.
FIELD OF THE INVENTION
This invention generally relates to automatically moving doors. More particularly, this invention relates to controlling movement of an automatically moveable door.
DESCRIPTION OF THE RELATED ART
There are various automated door arrangements used in various contexts. In some instances, the automated door slides in a direction parallel to the door panel between open and closed positions. This type of arrangement is commonly used for providing access to an elevator car.
Whenever an automated door moves toward a position where an edge of the door approaches another structural member in a closed position, it is possible for an object to get caught between the door and the other structural member. Various arrangements have been proposed to avoid such a situation.
In the case of elevator doors, it has been known to use a safety shoe that mechanically detects an obstacle near a closed position of a door by including a bar at the leading edge of the door. If an obstacle contacts the bar, that provides an indication that the door should not be fully closed automatically to allow for the obstacle to be removed so that it will not be caught between the door and another surface. Another example approach has been to use light-based detectors that generate a sensing light beam across an opening. If an obstacle is within the opening while a door is automatically closing and interrupts the light beam, the door will not be fully closed automatically to avoid the object being caught by the door.
There are limitations to such devices. For example, the safety shoe bar typically is not sensitive enough to detect relatively small objects such as a strap on a handbag or an individual finger. Additionally, such small objects may get caught if they are not located at the same position as the bar of the safety shoe. The light-based detectors are also limited in that an object may not be within the field of vision (e.g., the light beam) even though the object is in a position where it can be caught by the door. Another drawback to known light-based arrangements is that they are typically exposed to dust or debris that can interfere with proper operation. Another potential issue is presented if other light sources interfere with the detectors.
Another shortcoming of such devices is that they only address the possibility of an object being caught at the leading edge of the door as it moves toward a closed position.
It would be desirable to provide an improved arrangement for detecting when an object may be in a position to be caught by a door that is automatically moving. It would be beneficial to provide an arrangement that can detect the potential for an object being caught when a door is automatically moving toward a closed position, toward an open position or both. This invention addresses those needs.
SUMMARY OF THE INVENTION
An exemplary door assembly includes a door panel that is automatically moveable between open and closed positions. At least one switch is activated responsive to an increase in a gap at an interface between the door panel and another surface that the door panel moves past while the door panel moves between the open and closed positions. A controller controls automatic movement of the door responsive to activation of the switch.
In one example, the switch is supported on the door and is activated responsive to movement of the door panel away from the surface the door moves past. The switch is activated when the door panel moves in a direction generally perpendicular to a direction of movement of the door panel as it moves between the open and closed positions.
One example includes two switches. One switch is activated when a first amount of pressure is applied to the door panel. This switch provides an indication that an object may be in a position where it could become caught at the interface between the door panel and the other surface. Another switch is activated responsive to more pressure on the door panel. This other switch provides an indication that an object has become caught at the interface.
Another example includes a switch supported on a return panel associated with a door frame. In one example, the return panel has at least one portion that flexes or moves responsive to pressure applied by an object approaching or caught in the interface between the door and the return panel.
An exemplary method of automatically controlling movement of the door panel includes determining whether a gap increases at an interface between the door panel and another surface that the door panel moves past as the door panel moves between open and closed positions. If the gap increases, an indication that an object should be moved away from the interface can be provided, automatic movement of the door panel can be at least temporarily prevented, the door panel may be automatically moved in a first direction and then in a second, opposite direction, or a combination of more than one of these may be done responsive to determining that the gap has increased.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates an example door assembly.
FIG. 2 schematically illustrates one example sensor placement.
FIG. 3 schematically illustrates another example sensor placement.
FIG. 4 schematically illustrates another example sensor placement.
FIG. 5 is a flowchart diagram summarizing one example control strategy useful in an embodiment of this invention.
FIG. 6 is a flowchart diagram summarizing another example control strategy.
FIG. 7 is a flowchart diagram summarizing another example control strategy.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Disclosed examples include a sensor on at least one of a door panel or a door frame that allow for detecting when a gap between the door panel and the door frame is caused by an object being in a position relative to the door panel or door frame where the object may be caught during automatic movement of the door panel relative to the frame. With the example approach, a wider variety of objects may be reliably detected and a larger number of scenarios within which an object may be caught during automatic door movement can be addressed.
FIG. 1 schematically shows selected portions of an example door assembly 20 . Door panels 22 are automatically moveable between open and closed positions within an opening 24 . The example of FIG. 1 shows the door panels 22 in a closed position. In the illustrated example, each door panel 22 moves relative to a return panel 26 as the door panels 22 move between the open and closed positions. The return panel 24 is part of the door frame in this example and is adjacent a pocket for receiving the door panel 22 in the open position.
FIG. 2 schematically represents an end view of a door assembly as shown in FIG. 1 . Such an arrangement may be useful as an elevator door on the elevator car side or the hoistway side, for example. Each of the door panels 22 in this example includes a first switch 30 that is supported on the door panel 22 . In this example, the first switch 30 comprises a microswitch that operates in a known manner to provide an electrical output upon switch activation. In this example, an arm 32 of the first switch 30 is positioned relative to a first side 34 of the door panel 22 , which faces the interface 28 . In the illustrated example, at least a portion of the first switch 30 is physically supported to remain stationary relative to a second surface 36 of the door panel 22 .
Whenever pressure is applied on the first surface 34 , there will be some flexing or movement of the first surface 34 relative to the second surface 36 . In one example, this occurs because of the material used for the first surface 34 . A sheet of metal, for example, has some resiliency or flexibility such that it can be deflected toward the second surface 36 when pressure is applied onto the first surface 34 (e.g., from the bottom according to the drawing). The first switch 30 is positioned to detect such pressure on the first surface 34 and the switch arm 32 moves responsive to such pressure-induced movement of the first panel 34 .
The switch 30 provides an output indicative of the detected movement of the first surface 34 responsive to an object applying pressure against the first surface 34 . The output signal from the switch 30 is provided to a controller 40 that responsively controls automatic movement of the door assembly by controlling a door mover 42 . Example control strategies are described below.
In one example, the first switch 30 is configured to provide an indication of an amount of movement of the door panel 22 , such as movement of the first surface 34 relative to the return panel 26 , that corresponds to an increase in the gap at the interface 28 between the door panel 22 and the return panel 26 . An increase in the gap may correspond to deflection of the first surface 34 or movement of the entire door panel 22 in a direction that corresponds to an increase in the gap at the interface 28 . The increase will occur in some cases at only a localized portion of the interface 28 . Depending on the object, the gap along the entire interface 28 may change.
Microswitches are used in one example because they have the ability to provide a significant electrical output responsive to a very minor change in position of a switch component. In other words, microswitches are used in one example because of the ability to detect very small changes in a gap between the door panel 22 and the return panel 26 at the interface 28 .
The example door panels 22 also include a second switch 50 . An activating switch arm 52 in this example, moves responsive to a deflection or movement of the first surface 34 corresponding to increased pressure on the first surface 34 compared to the amount of pressure applied to cause the movement for activating the switch 30 . The switch 50 in this example provides a second level of object detection. Further movement of the first surface 34 in many circumstances will correspond to an object becoming caught at the interface 28 resulting in the increased pressure on and corresponding increased movement of the surface 34 . The second switch 50 provides an output to the controller 40 indicative of this condition.
FIGS. 1 and 2 show one example door arrangement. Another example is schematically shown in FIG. 3 . In this arrangement, the first switch 30 and the second switch 50 are supported on the return panel 26 . In this example, a portion 60 of the return panel 26 is flexible or moveable from a standard position responsive to an object approaching or getting caught in the interface 28 during automated door movement, for example. The illustrated example includes a portion 60 that is supported relative to a remainder of the return panel 26 so that the portion 60 can move between a rest position (shown in solid line) to a deflected position (shown in phantom in the drawing).
A first amount of movement or deflection of the portion 60 activates the switch 30 to provide an indication that an object is approaching the interface 28 . The second switch 50 is configured to provide an indication when a further deflection occurs corresponding to an object becoming caught at the interface 28 . As can be appreciated from the illustration, when the portion 60 moves from the position shown in solid lines to the position shown in phantom lines, the corresponding gap between the return panel 26 and the door panel 22 increases. The first switch 30 and the second switch 50 are supported and configured to provide respective indications of an initial amount of an increase in the gap and a further increase. The two switches provide corresponding outputs indicating conditions that are interpreted by the controller 40 as corresponding to an object being at the interface 28 or caught in the interface 28 .
FIG. 4 shows another example arrangement where first sensor 30 and a second sensor 50 are provided on door panels 22 A and 22 B. In this example, the door panel 22 A is a so-called high speed door panel and the door panel 22 B is a so-called low speed door panel. There is an interface 28 between the door panel 22 B and the return panel 26 . There is another interface 28 ′ between the door panels 22 A and 22 B. During movements between open and closed positions there is relative movement between the door panels 22 A and 22 B and between the door panel 22 B and the return panel 26 . The first switches 30 and second switches 50 allow for detecting an increase in the gap at either interface 28 or 28 ′ in the event that an object applies pressure against the corresponding door panel 22 A or 22 B.
FIG. 5 includes a flow chart diagram 70 summarizing one example control approach for controlling automated movement of a door panel responsive to an indication from at least one of the switches 30 , 50 regarding an object near or in the interface 28 . A decision is made at 72 whether the door panel of interest is stationary. If so, a decision is made at 74 whether the door is about to open. If not, the example of FIG. 5 allows for overriding or ignoring an output from one of the switches 30 or 50 under conditions where there is no likelihood that an object is going to become caught at the interface 28 because the door is not moving or not about to move.
In the event that the door is about to move, a decision is made at 76 whether the first switch 30 has been activated. If so, the example of FIG. 5 includes issuing an audible warning at 78 and a visual warning at 80 to advise an individual that there is an object in a position relative to the door panel 22 where the object may get caught during door movement. Other examples include only a visual warning. Still other examples include using only an audible warning. In one example, after the appropriate warning has been provided, a selected amount of time is allowed to elapse before commencing door movement.
In the example of FIG. 5 , when the door panel is moving (e.g., a negative result at the decision 72 ), a decision is made whether at least the first switch 30 has been activated at 82 . If so, the door stops at 84 and a timer begins to allow a predetermined amount of time to pass. A decision at 86 is made whether that time has passed. If not, the example of FIG. 5 includes continuing to monitor whether the switch is still activated indicating that an object is still in a position where it may be or is caught at the interface 28 . Once the appropriate amount of time has passed or the switch is no longer activated, a decision is made at 88 whether a door close instruction has issued. If so, the door is closed at 90 . If not, the door continues opening at 92 .
FIG. 6 includes a flow chart diagram 100 illustrating one example approach for responding to an indication from the first switch 30 regarding the presence of an object in a position where it may become caught at the interface 28 . In other words, the flow chart diagram 100 in the example of FIG. 6 summarizes one example approach for responding to an increase in the gap at the interface 28 that is small enough to only activate the first switch 30 . In this example, a decision is made at 102 whether the door is being opened. If not, a command is issued at 104 to ensure that the doors are fully closed. If the doors are being opened, a determination is made at 106 whether the first switch 30 has been activated. If so, the door stops moving at 108 . A timer begins running at 110 to allow for a predetermined amount of time to lapse before the door is allowed to move again. At 112 , a decision is made whether that time has passed. Until it has, the door remains stationary. After the time has passed, the door continues opening at 114 . During the time between stopping the door and opening the door, it is possible to provide at least one of an audible or visual warning to move an object away from the door panel 22 to reduce the risk of being caught at the interface 28 .
In some circumstances, enough pressure is applied on the door panel 22 to increase the gap between the door panel 22 and the return panel 26 , for example, to activate the second switch 50 . As mentioned above, the second switch 50 preferably is configured to be activated responsive to an amount of movement of the door panel 22 corresponding to an object being caught in the interface 28 . The example of FIG. 7 includes a flowchart diagram 120 summarizing one approach for responding to an output from the second switch 50 . In this example, if the door is not being opened a command to make sure the door is closed is issued at 104 .
If the second switch 50 has been activated at 126 , the door stops moving at 128 . A timer begins at 130 to allow for a predetermined amount of time to pass before the door will continue moving in an opening direction. In this example, the determination regarding that amount of time is made at 132 . If that amount of time has not passed, a command is issued at 136 to move the door in a closing direction for a short period of time to assist in removing any object that was caught at the interface 28 . In this example, the determination at 132 includes determining whether the amount of time for moving the door in the closed direction has passed, also. Once that has passed, the door continues opening at 134 .
In one example, continued movement of the door in the opening direction is carried out at a lower speed and with less torque than would have been done if no indication was provided from either the first switch 30 or the second switch 50 . In other words, one aspect of the example technique for controlling automatic door movement includes reducing the speed and torque used for opening a door responsive to activation of at least one of the switches to provide additional protection to the object involved. Using lower speed and lower torque also facilitates allowing for an object to be removed from the interface 28 in the event that it became caught but could not be freed during the reversed movement of the door in the closing direction for the short period of time.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.
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An assembly ( 20 ) for controlling movement of an automatically moveable door panel ( 22 ) includes sensors ( 30, 50 ) such as microswitches positioned on at least one of a door panel ( 22 ) or a door frame member ( 26 ). The sensors provide an indication of different levels of relative movement between the door panel and the door frame member at an interface ( 28 ) between them. Such relative movement includes an increase in a gap between them that corresponds to a situation when an object is at the interface ( 28 ) and may be caught. The sensors ( 30, 50 ) respectively provide an indication of when an object may become caught and when one has. Automated movement of a door is controlled responsive to an indication of the presence of an object in a location where the object may become caught during automatic movement of the door.
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BACKGROUND OF THE INVENTION
The present invention relates to a system of modular structural elements for building walls, particularly adapted for interiors.
In the technical field of building construction, engineers, architects and interior designers undertaking new-construction, renovation projects, or interior design work, are faced with the problem of optimizing the sub-division of building interiors, according to numerous factors including the type of building, the intended use of the building, and the aesthetic effect that one may desire to create when designing the building interior.
When building offices, for example, it is frequently desired to have large internal rooms which are subsequently sub-divided or partitioned according to the specific requirements of the occupants. In other commercial buildings such as showrooms, which typically have one or more large, undivided internal spaces, it may be subsequently desired to erect one or more interior walls to delimit one or more office spaces or meeting rooms. Similar problems are faced when renovating buildings to be used for a purpose other than that for which they were originally designed, and also when restoring old buildings that have planning restrictions or preservation orders placed on them, whereby the structure of the building can only be modified to a very limited extent.
In such cases, in homes and in workplaces, internal walls are erected to sub-divide the interior building space. However, it is frequently desired to erect internal walls which can be easily modified, to allow for any possible future changes in the use and/or aesthetic requirements of the building interior.
Modular internal walls have been developed which comprise a plurality of mutually interconnectable blocks. Known modular blocks for erecting internal walls typically comprise parallelepiped blocks, having a first vertical edge provided with a female connection groove, and an opposite and parallel vertical edge provided with a male connection element for connection to the female connection groove of an adjacent block. The upper and lower horizontal edges of the adjacent modular blocks have mutually facing connectors for mutually coupling the blocks horizontally.
However, such known modular blocks for building internal walls have some serious drawbacks, not least of which is the fact that they are often difficult to erect and require skilled personnel and special tools, equipment and cements or adhesives for installation. Furthermore, known modular blocks for building internal walls cannot be readily utilized to create special optical and decorative effects in the interior spaces of the building. Moreover only a limited number of geometrical configurations can be adopted when building internal walls with the known modular blocks, which cannot always be readily used, for instance, to erect walls having a curved configuration.
SUMMARY OF THE INVENTION
A pricipal aim of the present invention is to provide a system of modular structural elements that allows to erect, in a relatively simple and quick manner, both straight and curved walls with different radii of curvature, without using cements or adhesives between the structural elements.
An object of the present invention is to provide a system of modular structural elements which allows to erect walls without using any special tools, other than those normally used by an interior fittings installer.
Another object of the present invention is to provide a system of modular structural elements which allows to quickly and easily erect walls, partitions, and the like that can create special optical and decorative effects in the interiors of living or working spaces.
With this aim, these and other objects in view, there is provided a system of structural elements particularly for internal walls, as defined in the appended claims.
Advantageously, the system of structural elements according to the invention comprises a plurality of modular components, and each one of said modular components is constituted by two halves that are held together by fixing means.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects and advantages of the present invention will become apparent from the following detailed description of some currently preferred embodiments thereof, described only by way of non-limitative example with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic exploded perspective view of a portion of a wall that can be obtained with the system of structural elements according to the invention;
FIG. 2 is a perspective view of a hollow modular component formed by two mutually opposite half-shells;
FIG. 3 is a sectional view, taken along the plane III--III of FIG. 2;
FIG. 4 is a plan view of the inside of a male half-shell of the modular component of FIG. 3;
FIG. 5 is a sectional view, taken along the plane V--V of FIG. 4;
FIG. 6 is a top view of the half-shell of FIG. 4;
FIG. 7 is a side view, taken from the left, of the half-shell of FIG. 4;
FIG. 8 is an enlarged-scale sectional view of a detail, taken along the plane VIII--VIII of FIG. 7;
FIG. 9 is an enlarged-scale sectional view of a detail, taken along the plane IX--IX of FIG. 7;
FIG. 10 is a plan view of the inside of a female half-shell of the modular component of FIG. 3;
FIG. 11 is a sectional view, taken along the plane XI--XI of FIG. 10;
FIG. 12 is an enlarged-scale sectional view of a detail, taken along the plane XII--XII of FIG. 10;
FIG. 13 is a top view of the half-shell of FIG. 10;
FIG. 14 is an enlarged-scale sectional view of a detail, taken along the plane XIV--XIV of FIG. 13;
FIG. 15 is an enlarged-scale sectional view of a detail, taken along the plane XV--XV of FIG. 13;
FIG. 16 is a side view, taken from the left, of the half-shell of FIG. 10;
FIG. 17 is a partial perspective view of a male half-shell, to which locking and trimming profiled elements are applied;
FIG. 18 is a front elevation view of a different embodiment of the hollow modular component, with two half-shells, of the system of structural elements according to the invention;
FIG. 19 is a bottom plan view of the hollow modular component of FIG. 18;
FIG. 20 is a top plan view of the hollow modular component of FIGS. 18 and 19;
FIG. 21 is a lateral elevational view of the hollow modular component of FIGS. 18-20, as seen from one side thereof;
FIG. 22 is a lateral elevational view of the hollow modular component of FIG. 18-21, as seen from another side thereof;
FIG. 23 is a perspective view of a locking and trimming profiled element;
FIG. 24 is a sectional lateral elevational view of two superimposed modular components of FIGS. 18 to 22, held together by profiled elements according to FIG. 23;
FIG. 25 is a view, similar to FIG. 24, also showing a different embodiment of the locking and trimming profiled element with snap-action locking;
FIG. 26 is a sectional lateral elevation view showing another embodiment of the locking and trimming profiled element interconnecting two hollow modular components;
FIG. 27 is a sectional lateral elevation view similar to FIG. 26, showing a different embodiment of the locking and trimming profiled element interconnecting two hollow modular components;
FIG. 28 is a sectional lateral elevation view similar to FIG. 26, showing a further embodiment of the locking and trimming profiled element interconnecting two hollow modular components of the system of structural elements according to the invention;
FIG. 29 is a perspective view, with parts shown in cross-section, of a further embodiment of the system with modular components, each component being formed by two panel-like elements with profiled ends that are kept together and spaced by adapted locking and trimming profiled elements; and
FIG. 30 is a side view of a locking profiled element for obtaining curved walls from modular components or from panels.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the accompanying drawings, identical or similar parts have been designated by the same reference numerals.
Initially with reference to the embodiment shown in FIGS. 1 to 17, the system of structural elements for forming a wall, particularly an interior wall, is formed by a plurality of modular components 1, a plurality of locking and trimming profiled elements 2, and by a base and top profile 3.
Each modular component 1 has the shape of a parallelepiped, with two larger faces 4 having a square or rectangular contour and vertical sides 5 and horizontal sides 6 that are relatively narrow and are affected by four raised portions, designated by the reference numeral 7 on the vertical sides and by the reference numeral 8 on the horizontal sides, which are aligned in pairs and spaced from one another.
Advantageously, each modular component 1 is constituted by two half-shells 9 and 10 that are mutually adjacent, are engaged by a male-female coupling, and delimit an internal space 11.
More particularly, the half-shell 9 is a male half-shell having, at the edge 12 for mating with the female half-shell 10, a protruding pin or peg 13 in each corner and a straight raised portion 14 (which constitutes an extension of the outer surface) or a plurality of straight raised portions which are aligned along at least part of each side or lateral face 5 and 6. The female half-shell 10 has, at its edge 12 for mating with the male half-shell 9, at each corner, a hole or seat 15 for accommodating a corresponding pin or peg 13 of a male half-shell and has a corresponding external straight recess 16 or a plurality of straight recesses which are aligned along at least part of each lateral face 5 and 6.
Preferably, the raised portions 7 and 8 on the lateral faces 5 and 6 of the half-shells 9 and 10 are shaped so as to provide a dovetail male-female coupling, i.e., they have a slight undercut to engage and anchor in corresponding seats in the bottom profiled element 3 or in the locking profiled element 2, as explained hereinafter.
Each bottom or top covering profiled element 3 (FIG. 1) can be constituted by an extruded part made of light alloy or plastics that is symmetrical with respect to a median longitudinal sectional plane. More particularly, it is formed by a C-shaped inner core 20 which delimits an internal interspace 21 and by a double lateral set of wings that forms, on each side of the profiled element, an external trimming edge 22 and two longitudinal grooves 23 and 24 that are directed on opposite sides with respect to each other. The opposite lips of each groove 24 are preferably provided with a ridge 25 that forms an undercut for snap-together engagement with the raised portions 7 and 8 of the modular components 1.
The grooves 23 are instead meant to engage the free edges of a profiled or solid U-shaped element 26, made for example of metal or plastics, which is fixed, for example by means of bolts that can be screwed into wall anchors or by means of screw anchors, to the floor or ceiling of a room or to a vertical wall thereof.
In order to fix a bottom profiled element 3 at its tip, it is possible to use an L-shaped element 27 which, with one of its wings 28, enters the internal interspace 21 of the bottom profiled element and is coupled to a profiled element 3 by means of a screw that passes through the hole 29; at its other wing 30, said L-shaped element can be fixed, for example by means of screw anchors or nails that pass through the holes 31, to a side wall or to the ceiling or to the floor of a room in which a wall must be erected with the system according to the present invention.
Each one of the locking and trimming profiled elements 2 is formed by a U-shaped metal or plastic profiled element 32, having a T-shaped ridge 33 extending from a rear surface thereof; said ridge delimits, together with the U-shaped portion, two opposite longitudinal seats 34 and 35 for accommodating and retaining raised portions 7 and 8 of the modular components 1. The stable coupling between the modular component and the locking profiled element is best ensured by the precision of the fit between the seats 34 and 35 and the raised portions 7 and 8. For this purpose, the inlet lips of the seats 34 and 35 can preferably have a slight undercut for snap-together coupling and retention in a more stable position.
Furthermore, the outer face of the transverse wing of the T-shaped ridge 33 constitutes a trimming surface, which is optionally painted and/or anodized in the desired color or colors, at the gap regions between one modular component 1 and the next.
The locking and trimming profiled elements can equally have a straight shape, to, build straight walls, and a curved shape, for curved walls or wall portions. In FIG. 1, the profiled elements 2 are used in pairs, one on each side of the modular components 1.
According to a preferred embodiment of the invention, the modular components 1 are shaped like a parallelepiped, measuring for example 193×193×78 mm, and are made of transparent plastics with high impact-resistance and good weather-resistance characteristics, particularly resistance to ultraviolet rays and to scratching, such as for example polycarbonate, polymethyl methacrylate, glass, and the like.
The surfaces of the internal space 11 can be machined or variously shaped so as to distort images in a desired manner without appreciably reducing the passage of light. Furthermore, the material of which the half-shells 9 and 10 are made can be of various tints or colors according to the desired optical effects.
The installation of a system of modular components according to the present invention is extremely easy, quick, and precise, and can be performed even by personnel that has not been particularly trained.
FIGS. 18 to 22 illustrate another embodiment of a modular component 1a, which instead of the raised portions 7 and 8 has two straight and parallel tabs 7a and 8a on each side, one on each half-shell 9 and 10.
In the embodiment of FIGS. 23 to 25, the modular components 1b have raised portions 7 and 8 or tabs 7a and 8a that are offset on adjacent sides 5 and 6; i.e., on one side the raised portions or tabs have a given spacing or mutual distance and a greater or smaller spacing on an adjacent side, whereas the locking and trimming profiled elements 42 are substantially S-shaped in cross-section, so as to form two mutually opposite seats 43 and 44 in order to engage, on one side, a side of a modular component 1 with tabs or raised portions that are spaced with a given spacing and, on the other side, a side of an adjacent modular component with tabs or raised portions having a different spacing.
In FIG. 25, the mutual engagement of raised portions 8 of two modular components 1b and profiled elements 42 occurs in a snap-together manner, by virtue of the undercut configuration of the seats 43 and 44 and of the raised portions or tabs 7 and 7a, 8 and 8a.
In the embodiment of FIG. 26, the locking and trimming profiled elements are shaped like those of FIGS. 24 and 25 but are coupled to each other by a transverse connecting portion 45.
FIGS. 27, 28, and 29 show a corresponding number of embodiments of monolithic locking and trimming profiled elements, respectively 46, 47, and 48, which are particularly adapted when, instead of each modular component 1, two panels 49 and 50 are used, said panels being provided with a raised peripheral contour edge 51 or with a peripheral groove 52 but not mutually rigidly coupled, being rather merely adjacent or free and mutually spaced (FIG. 29).
FIG. 30 is a view of a locking and trimming profiled element 56 that is similar to the profiled element 48 of FIG. 29, but is provided with ridges for engaging the edges 51 of the panels or the raised portions or tabs 7 and 8 that are arranged at an angle, in a symmetrical fashion, with respect to the median axis x--x of the profiled element. More particularly, the profiled element has two external ridges 57 that are higher than the two internal ridges 58 but have the same inclination (in the opposite direction) with respect to the axis x--x, for example 3-5 degrees.
The above described system of structural elements is susceptible to numerous modifications and variations within the protective scope defined by the content of the appended claims.
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The system has hollow parallelepiped modular components which are each composed of two interlocking half-shells. Raised portions provided on the sides of the modular components engage seats formed in respective locking and profiled elements for interconnecting the modular components. A profiled element is provided for covering the upper and lower edges of the mutually interlocked modular components. The profiled element has a C-shaped inner core, provided with grooves defining undercut ridges for snap-together engagement with the raised portions of adjacent modular components, and a U-shaped profiled element for housing the C-shaped inner core. L-shaped elements, provided for fixing the assembled system, each have one wing fixable within an interspace defined within the C-shaped inner core and another wing fixable to a wall, floor or ceiling.
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BACKGROUND OF THE INVENTION
The present invention relates to tube sockets and more particularly to tube sockets adapted to be used with tubes having balanced filament feeding and which are so constructed as to be able to accommodate high power requirements (including filament currents on the order of 250 amperes), high frequencies (up to 150 megacycles), and withstand high shock or gravatational requirements (on the order of 18 G's).
In electron tube applications, such as amplifiers, oscillators and the like, involving very high frequencies, designers of prior art tube socket assemblies, such as that disclosed in U.S. Pat. No. 2,427,563 to Lavoie, have recognized the advantages of utilizing an integrated structure by "sandwiching" bypass capacitors and connectors. Such a construction affords paths of low impedance for tube element connections to ground without necessitating externally placed capacitors and the resultant wiring problems. In addition, the patent to Lavoie stresses the need for keeping the length and inductance of the leads to the tube elements and between stages to a minimum to avoid objectionable regeneration and parasitic oscillations by stray electrostatic or magnetic coupling and by the effect of a common impedance between stages when a single power supply is used. This is accomplished in Lavoie by providing an integrated tube socket comprising a plurality of metallic stacking plates arranged in spatial relation to contact corresponding terminals on a tube, separated by suitable dielectric elements so as to constitute bypass capacitors which may be connected to ground and to the appropriate external circuit components to provide the aforementioned low impedance paths to ground.
Another example of a known tube socket assembly having integrated bypass capacitors positioned between the tube contactors is shown in FIG. 1. The socket assembly 100 shown in FIG. 1 comprises a base plate 102, a screen contact ring 104, a grid contact ring 106, and a ground ring 108. Positioned between the base plate 102 and contact rings 104, 106, 108 are bypass capacitors 110, 112, and 114. Located beneath the tube, which is shown by phantom lines, is a filament contact 116 supported by a plastic filament support 118 which in turn is supported by a cathode contact ring 120. The cathode contact ring 120 has a cylindrical extension 122 which provides electrical contact with the tube. Electrically connected to the anode of the tube is the anode contact ring 124. A plurality of threaded rod and nut constructions secure the assembly together to provide an integrated tube socket assembly.
Another concern of tube socket designers is that in operation of tubes at high frequencies using direct heating (i.e. introducing the signal at the filament) it is desirable to feed the modulated signal across the filament using a "balancing" technique. Balancing introduces the signal into each of the two leads of the filament in synchronous fashion. To introduce the signal across the two leads, capacitors are utilized. Although integration of the components into the assembly is desirable, it is impracticable to utilize wafer thin, "sandwiched" bypass capacitors, such as shown in FIG. 1, due to the nature of the assembly; i.e. the capacitors are not connected to a ground plate or connector. Accordingly, balancing has been achieved using external capacitors to feed the signal into the tube socket for entry at the filament. However, the wiring or leads connecting the externally located capacitors have caused problems due to the introduction of stray inductance and capacitance. At high frequencies the size of the leads and lead length is critical in avoiding resonance problems developed by the inductive and capacitive components associated with stray capacity attributable to the closeness of leads to ground and to each other.
Accordingly, it is an object of this invention to provide an integrated tube socket structure which minimizes lead lengths associated with balancing capacitors used in a filament feed for a high power, high frequency tube.
Another important consideration in the design of a tube socket is the provision of passages for allowing cooling air through the interior of the socket assembly to the tube. U.S. Pat. No. 2,977,494 to Johnstone, et al., discloses the use of annular slots or ducts formed in a base plate to provide for the passage of cooling air within the tube socket directed so as to strike the tube. Similarly in tube sockets of the prior art, elaborate measures have been utilized to provide a cooling effect. U.S. Pat. No. 3,042,893 to Chin, et al., discloses channels formed in the vicinity of the tube base. However, one potential disadvantage when utilizing tube socket constructions having the above mentioned provisions for cooling the tube is that the RF developed during high frequency usage may be transmitted through such cooling openings into the socket assembly so as to interfere with the functioning of the terminals exposed by the openings.
Accordingly, it is an object of the present invention to provide a tube socket assembly which incorporates annular cooling holes for cooling the anode which are so configured as to prevent RF from entering the tube socket assembly.
Another object of the present invention is to provide a tube socket assembly which incorporates an assembly of low inductance annular plates wherein the capacitance required by the various connectors is physically integrated into the tube socket structure.
A further object of the present invention is to provide a tube socket having a balanced filament feed provided by integrally contained capacitors so as to minimize stray inductance and capacitance when the tube is operating at its operating frequencies. Furthermore, because the length of the path of travel of currents through the tube socket assembly is significant at high frequencies, another object is to equalize the paths of travel of the signal as it is introduced into each of the two leads of the tube filament.
Still another object of the present invention is to provide a tube socket having contact rings which are fabricated with sufficient strength to support the tube when subjected to shocks exceeding 18 G's and having sufficient mass to transfer tube element heating from the metal/ceramic seals of the tube, and to maintain the seal temperature below manufacturer's specified temperature (approximately 250° C.) when operated under worst case conditions.
Additional objects and advantages of the invention will become apparent to those skilled in the art upon further review of the following description of the invention.
SUMMARY OF THE INVENTION
The present invention achieves the above objects and provides a tube socket assembly for electron tubes capable of operating at high frequencies with high power output requirements. The tube socket assembly is considered universal in nature as it is designed for use in low or high input impedance circuits (grounded grid, or grounded cathode operation) with only a slight modification of the tube socket configuration. The design of the tube socket assembly provides excellent isolation between the input and output circuits.
The tube socket assembly of the present invention is a generally annular construction arranged around a vertical center line and comprises a plurality of contactor rings with central openings. The annular contactor rings are fabricated from aluminum and/or brass alloys having a thickness of approximately 1/4 inch, so as to present minimal inductance at both high and low frequencies and to support the tube when subjected to shocks of up to 18 G's. Also, due to the dimensional thickness of the contactor rings, the mass is such as to allow adequate convection to provide a cooling effect. Both upper and lower contactor rings are stacked vertically and are appropriately spaced to provide the corresponding contact with the tube element contact. A removable bolt construction securely positions the upper contactor rings, i.e. a screen grid contactor, a grid spacer, a control grid contactor, and a grid/ground contactor, whereby the spacing of the contactor rings may be changed by removing the bolts and utilizing a different positioning arrangement. In the lower portion of the tube socket assembly spaced filament contactors are arranged for contact with the corresponding tube filament contacts. To facilitate airflow through the socket to cool the tube anode, iris cutouts or cooling holes circumferentially located adjacent the central openings in the upper contactor rings provide through vertical channels for the passage of air which are so configured as to screen out RF signals which might interfere with the linear operation of the tube. The holes are dimensioned so as to prevent passage of RF operating frequencies therethrough. Annular thin film double clad mylar bypass capacitors are physically integrated into the design of the upper portion tube socket assembly by being sandwiched between the cover and the screen grid contactor, the screen grid contactor and the grid spacer, the grid spacer and the control grid contactor, and the control grid contactor and the grid/ground contactor, and are substantially coextensive therewith so as to eliminate the need for external bypass capacitors. Through the integration of the thick contact rings and the thin film bypass capacitors, the electrical components that affect frequency are equally distributed and, therefore, improved frequency stability is achieved. Separate discrete lump balancing capacitors are used in conjunction with the filament contactors which transmit the modulated signal so as to create an equal path of conductance to each of the contacts of the tube filament from which the modulated signal is emitted. The balancing capacitors are integrated into the physical structure of the tube socket assembly and are positioned so as to be fixed or sandwiched between the filament contactor elements so that the distance travelled by the modulated signal through both contact leads is substantially the same to facilitate balancing. Furthermore, the contactor rings of the present invention are of sufficient thickness (e.g. one quarter of an inch) to reduce inductive problems. The screen grid and control grid contacts on the tube are embraced by the corresponding contactor rings through resilient finger contacts extending around the entire inner periphery of the contactor ring to reduce contact resistance, capacitance and inductance.
BRIEF DESCRIPTION OF THE DRAWINGS
The attendant advantages of the present invention will be readily apparent from the following detailed description thereof which is presented in conjunction with the accompanying drawings, wherein:
FIG. 1 is a partial cross sectional view of a prior art tube socket assembly;
FIG. 2 is a side view of the preferred embodiment of the present invention;
FIG. 3 is a plan view of the FIG. 2 embodiment;
FIG. 4 is a cross sectional view showing a tube in phantom lines taken along a line 4--4 in FIG. 3;
FIG. 5 is a partial cross sectional view taken along line 5--5 in FIG. 3 showing the bolted construction which holds the contactors in place;
FIG. 6 is a partial cross sectional view taken along line 6--6 in FIG. 3 showing the electrical connection to the control grid contactor;
FIG. 7 is a partial cross sectional view taken along line 7--7 in FIG. 3 showing the electrical connection to the screen grid contactor;
FIG. 8 is a cut-away view taken along the line 8--8 in FIG. 2 showing the feed contactor and balancing capacitors; and
FIG. 9 is a schematic representation of the filament connections in the FIG. 2 embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, FIG. 2, a side view, shows a tube socket assembly 10 having a cover 12 adapted to be mounted in a housing (not shown). Arranged underneath cover 12 in layer-like fashion are a plurality of annular elements fabricated from aluminum, aluminum alloys or brass alloys. More specifically, arranged in descending order as seen in FIG. 2, are a screen grid contactor 14, a grid spacer 16, a control grid contactor 18, and a grid/ground contactor 20. These annular elements have outside diameters of approximately 10 inches and inside diameters ranging from approximately 4 to 4.2 inches. In the preferred embodiment, the contactors 14, 18, 20 are approximately 1/4 inch thick to minimize inductance at high frequencies and the grid spacer 16 is approximately 1/2 inch thick. It can be readily appreciated by those skilled in the art that due to the annular configuration and dimensonal thickness and width of contactors 14, 18, 20 inductance problems normally associated with the dimensional thickness and width are minimized. It should be noted, however, that the specific dimensions given above are merely exemplary and various dimensional changes could be made to accommodate various types of tubes within the purview of the invention.
As best seen in FIG. 4, a cross sectional view, the control grid contactor 18 and the screen grid contactor 14 are electrically connected with the corresponding tube contacts by means of contact rings 22, 24 which comprise closely spaced resilient, finger-like projections. Substantially the entire circumference (360°) of each respective tube contact is engaged by the finger-like projections of the contact rings 22, 24 so as to eliminate "hot spots", and resistance, capacitance and inductance are minimized. Furthermore, the finger-like projections provide a uniform feed to the tube contact rings. Due to the placement of screen grid contactor 14 (i.e. below cover 12), when cover 12 is grounded the screen grid is effectively isolated from RF emitted from the tube.
Integrated into the physical structure of assembly 10 are four, annular thin film bypass capacitors 26, 28, 30, 32 which provide low impedance paths to ground at high frequencies. The bypass capacitors may be fabricated utilizing a centrally positioned mylar dielectric which is sandwiched between two thin sheets of copper. The capacitance developed by the capacitors when installed between the contactor elements is determined by the following equation (neglecting fringe effects at the edges of the capacitor plates):
C=0.225 e.sub.r [(N-1)A/T] picofarads
where:
A=Area of one side of one plate in square inches
N=Number of plates
T=Thickness of dielectric in inches
e r =Dielectric constant (for Mylar the dielectric constant is 2.89)
Thin film bypass capacitor 26 is positioned between cover 12 and screen grid contactor 14. The bypass capacitor 28 is sandwiched between the screen grid contactor 14 and the grid spacer 16, which is grounded. Sandwiched between grid spacer 16 and control grid contactor 18 is bypass capacitor 30, while bypass capacitor 32 is sandwiched between grid/ground contactor 20 and control grid contactor 18.
The cover 12, contactors 14, 18, 20, grid spacer 16 and bypass capacitors 26, 28, 30, 32 are rigidly secured together by four bolts 34 and nuts 36 in removable fashion, as shown in FIG. 5. Consequently if a tube is to be inserted into the socket assembly having a different contact spacing, tube assembly 10 may be disassembled and contactor elements of different dimensions or spacer elements could be utilized to achieve a mating effect. As seen in FIG. 5, insulating cylinders 38, 38A prevent the screen grid contactor 14 and control grid contactor 18, respectively, from being grounded by bolts 34.
Referring once again to FIG. 4, a tiered construction is provided in the lower portion of tube socket assembly wherein upper filament contactor 40, feed contactor 42, and lower filament contactor 44 are rigidly positioned by rods 46 (one of which is shown in FIG. 4), flanged insulators 48, and spacing elements 50. Each of the rods 46 have threaded ends; one of which is threaded into a correspondingly threaded hole in the grid/ground contactor 20 and the other end is in threaded engagement with a nut or suitable fastening means. The flanged insulators 48 and spacing elements 50 may be fabricated from fluoroplastics, such as TFE and PFA. The rigid construction provided by the dimensional thickness of contactors 40,42,44 in conjunction with spacing elements 50 and rods 46 allow the socket assembly 10 to withstand shocks of up to 18 G's. As shown in FIG. 8, each of contactors 40,42,44 have annular central portions (approximately 43/4 inches in diameter in the preferred embodiment) and four radially extending appendages (extending approximately 10 inches from end to end in the preferred embodiment). In addition, lower filament contactor 44 is provided with an inner cylindrical extension 44A which provides a connection between the lower filament contactor 44 and the corresponding first filament contact on the base of the tube (not shown). As best shown in FIG. 3, the upper portion of inner cylindrical extension 44A comprises a plurality of resilient finger-like contacts extending around the entire circumference for providing 360° circumferential electrical contact with the corresponding contact on the tube. Similarly, an outer cylindrical extension 40A formed of a plurality of closely spaced, vertically extending finger-like projections is fastened on the upper filament contactor 40 for connection with the second filament contact on the tube. As shown in FIG. 4, inner and outer cylindrical extensions 40A, 44A may be fastened to the upper and lower filament contactors 40, 44 by suitable fastening means such as screws and then brazed with solder or other suitable high temperature materials. Note that both of the cylindrical extensions 40A, 44A provide a full 360° of contact, thereby eliminating "hot spots". Mounted on upper filament contactor 40 are a plurality of pins or tube stops 45 (one of which is shown in FIG. 2) which abut the tube and limit its downward movement.
The electrical circuitry mbodied by the contactors 40,42 and 44 is best understood by referring to the schematic representation depicted in FIG. 9. Filament contactors 40,44 correspond to leads A,B which provide the base level electrical input into the filament. Feed contactor 42 is represented by lead C in FIG. 9 which carries the modulated signal. Capacitors connect the lead C with the leads A,B to provide a balanced input by creating equal paths of travel for the modulated signal. This balancing technique results in emission of a modulated signal from the filament with a minimum amount of distortion at high frequencies.
As to the actual physical structure of the balanced, capacitive, coupled input to the tube filament, the value of the capacitors to be used is determined by the lowest frequencies to be amplified by the tube. By employing lump value capacitors, large values of capacity; e.g. 3300-13,000 picofarads, can be achieved while utilizing minimum space.
The capacitors utilized for such a balancing technique are uniquely integrated into the physical structure of tube socket assembly 10 as shown in FIGS. 2, 3, 4 and 8. Lump capacitors 52, extend between upper contactor 40 and feed contactor 42 and are secured by suitable fastening means such as screws or the like extending through holes in contactors 40,42 which also provide suitable electrical connection. Likewise, capacitors 54 extend radially between the inner cylindrical extension 44A and the inner periphery of feed contactor 42. Suitable fastening means such as screws or the like are utilized for securing lump capacitors 54 to provide a secure electrical connection. The socket assembly 10 is constructed to accommodate four symmetrically positioned capacitors 52, one at each of the junctions of the appendages of the feed contactor 42 (two capacitors 52 being utilized in the preferred embodiment as shown in FIG. 8) and four symmetrically positioned capacitors 54, one at each of the linear portions on the inner periphery of feed contactor 42 (two capacitors 54 being utilized in the preferred embodiment as shown in FIG. 8). Due to the precision positioning of the capacitors 52,54 the distance travelled by the modulated signal from the feed contactor 42 through capacitors 52, upper filament contactor 40, outer cylindrical extension 40A, and eventually to the tube filament is substantially equal to the distance travelled by the modulated signal from the feed contactor 42 through capacitors 54, cylindrical extension 44A and eventually to the tube filament. Consequently, at high frequencies a balancing effect is achieved whereby distortion of the modulated signal is avoided.
Referring now to FIG. 3, the cover 12 substantially surrounds the circumference of the tube base (not shown in FIG. 3) so as to substantially impede RF from being transmitted to the elements located below cover 12. However, slots or openings 56 are provided through the tube socket assembly 10 to cool the tube anode. Openings 56 are so dimensioned such that the only RF which could enter the openings is generated only above the cutoff frequency of the tube, thus precluding a potential source of RF feedback. Corresponding openings are provided in the bypass capacitors 26, 28, 30, 32, the contactors 14, 18, 20 and grid spacer 16. Furthermore, the annular portions of contactors 40,42,44 do not extend to the inner periphery of openings 56 so that through openings 56 allow cooling air to circulate from the lowermost portion of socket assembly 10 through cover 12 to the anode of the tube. Additionally, ventilation holes 58 are also provided in contactor 44 as seen in FIG. 8.
The size of the openings 56 determines the air pressure required for adequate air flow. Openings 56 of the preferred embodiment are approximately 12.75 square inches. A general equation used to determine the forced air required in cubic feet per minute (CFM) to determine the air temperature rise in degrees Fahrenheit with a given air flow in CFM is: ##EQU1## where:
3160--a constant
KW--Maximum anode dissipation in kilowatts
Δt(F)--The air temperature rise above ambient temperature in degrees fahrenheit.
For example, in a given application it is desirable to keep the anode exhaust temperature below 212° F. with full anode dissipation of 10,000 watts. The ambient temperature in the tube housing is 78° F. so that maximum desirable rise is 134° F. (78°+134°=212° F.). Using the airflow equation: ##EQU2## Thus, the input volume of 78° F. air in CFM must be equal to or greater than 235.8 CFM to maintain the air outlet temperature below 212° F.
However, when operating at high frequencies the dimensions of openings 56 must be limited to prevent RF from being fed back from the output to the input. The following equation can be utilized to determine whether the distance A, as represented in FIG. 3, is beyond the critical cutoff wavelength using the following equation: ##EQU3##
f 1 =highest operating frequency in megahertz
A=circumferential dimension of the opening in feet
λ 1 /2=one half wavelength corresponding to the frequency f 1
λ 1 2=492 ft./f 1
If the critical cutoff wavelength, λc, is imaginary, then RF will not penetrate the opening. However, if λc is a real number, the RF will penetrate. Using the values of A=0.42 feet and f 1 =100 MHz, the highest operating frequency, an imaginary number was found for λc. Consequently, openings 56 (measuring 0.42 feet in the circumferential direction in the preferred embodiment) will not be penetrated by RF at frequencies of 1000 MHz and below.
Electrical connector subassemblies 60,62 for connecting the external circuitry to grid contactor 18 and screen contactor 14, respectively, are shown in FIGS. 6 and 7. At opposite ends of each of the subassemblies 60,62 are coaxial connectors 64,66 for connection to the external circuitry, and contacts 68,70 which are resiliently biased for continuous connection with the contactors 18, 15, respectively, by bananna jacks, 72,74 (as these resilient extensions are referred to in the art). Insulator sleeves 76,78 surround the internal conductors of the subassemblies 60,62. Suitable fasteners, such as screws the like, engage collar elements 80,82 to secure the subassemblies 60,62 to grid ground contactor 20 to provide a secure, rigid connection. Due to the nature of the fastener construction as well as the resiliency of the contacts, tube socket assembly 10 is capable of withstanding shocks occasioned in such uses as jet aircraft approaching 18 G's.
As stated in the foregoing, the tube socket assembly 10 may be converted from the grounded grid configuration (shown in FIGS. 1-9) to a grounded cathode operation. To accomplish this, the grid spacer 16 and the grid/ground contactor 20 are removed and replaced by insulated spacers. An insulated annular spacer is utilized to replace grid spacer 16 and the insulated spacers 50 are extended to the control grid contactor 18 to compensate for the removal of the grid/ground contactor 20. All bypass capacitors are removed except for bypass capacitor 26 located between the plate 12 and the screen grid contactor 14. In addition, the electrical connector assemblies 60,62 are mounted directly to the grid contactor 18 and screen contactor 14, respectively. Furthermore, since the modulated signal is introduced at the grid rather than the filament, the feed contactor 42 and balancing capacitors 52,54 can be removed.
Obviously, other embodiments and modifications of the present invention will readily come to those of ordinary skill in the art having the benefit of the teachings presented in the foregoing description and drawings. It is, therefore, to be understood that this invention is not to be limited thereto and that said modifications and embodiments are intended to be included within the scope of the appended claims.
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An electron tube socket assembly capable of withstanding shocks up to 18 G's, operating in the frequency range of 10 KH to 1000 megahertz and conducting filament currents on the order of 250 amperes. Stacked contactors are positioned so as to encircle corresponding ring contacts on an electron tube. Film-type capacitors are positioned between the contactors so as to be physically integrated into the construction of the tube assembly. Lump capacitors associated with the delivery of the modulated RF signal to the filament element of the tube are physically positioned between the filament contactors such that the delivery of the modulated RF signal through the capacitors and each of the filament contactors is substantially equidistant and a balancing effect is achieved. The contactors contain apertures dimensioned to allow cooling air to pass through to cool the anode of the tube being used in the socket assembly yet prevent the feedback of RF energy from the tube output to the tube input.
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TECHNICAL FIELD
The present invention relates to improvements relating to surfactant compositions, a method of treatment of textiles and a nano-composite textile.
BACKGROUND OF THE INVENTION
It is well known to use particles to modify the surface of cotton fibres. Consequently, particulate inorganic materials such as clays, silica and alumino-silicate have been widely used in detergent compositions. Typically, these are present as ‘softeners’ which associate with the surfaces of fibres and fibrils of cotton.
In recent years it has been proposed to use so-called ‘nanoparticles’ for fabric treatment. WO 02/064877 (P&G) discloses coating compositions, which comprise a ‘nanoparticle’ system of a size of less than or equal to 750 nm, with a lower limit of ‘0’ nm. Examples provided include synthetic silica (10–40 nm), boehemite alumina (2–750 nm) and ‘nanotubes’ (2–50 nm). Clays, particularly plate-like laponites (25–40 nm wide and ˜1 nm thick) are considered suitable and organic materials such as nano-latexes are proposed.
Nanosilica particles are negatively charged and are not expected to deposit on the fabric surface (also negatively charged) during wash because of their negative charge. At pH 8, for example, the Zeta-potential of a nanosilica was measured to be −21 mV.
EP 1371718 (Rohm and Haas) discloses 1–10 nm polymeric nanoparticles as a fabric care additive. These can be organically modified with silicones.
WO 02/18451 (Rhodia) discloses the use of nanoparticles in a polymeric or nano-latex form.
DE 10248583 (Nanogate Technologies GmbH) discloses the use of inorganic nanoparticles as a carrier for a silane material.
BRIEF DESCRIPTION OF THE INVENTION
We have determined that it is advantageous to use monomeric hybrid organic/inorganic nanoparticles of the size range 1–10 nm. These materials are not polymeric and typically comprise an inorganic core with chemically bound organic pendant groups.
Accordingly therefore, the present invention provides a laundry treatment composition comprising:
a) 0.001–5% wt of monomeric hybrid organic/inorganic nanoparticles having a particle size of 1–10 nm,
b) 0.1–95% wt of surfactant
c) optionally, one or more of enzymes, perfumes, bleach, and sequesterants.
A first benefit of the present invention is believed to be that fabrics treated with the composition are easier to wash after subsequent soiling.
According to a further aspect of the present invention there is provided a method of treating cellulosic textiles, which comprises contacting the textile with a solution of the composition according to the present invention.
Textile here is intended to mean both a fibre in the form of a yarn, and especially, in the form of a woven or knitted garment. Generally the method of the invention will be applied as part of a domestic laundering process although it can also be applied as finishing process in textile or garment manufacture.
While not wishing to be limited by any theory of operation, it is believed that the nanoparticles of the composition of the invention penetrate into the cellulosic regions of the cotton fibre rather than simply associating with the surface of the fibres or penetrating into the lumen of the fibres. It is considered that the mechanism of delivery of nanoparticles is nano-filtration, through cotton fibre pores. These pores are believed to be of a typical size between 5–9 nm.
It is also believed that nanoparticles prevent the absorption of particulate soil into cotton fibre pores.
This is believed to be due to two mechanisms. In the first of these, the nanoparticles are thought to block the pores and prevent adsorption of particulate soils.
It is preferable that the nanoparticles are negatively charged under the conditions of a domestic wash, i.e. that they have a negative Zeta-potential at an alkaline pH suitable for washing clothes. It is believed that this enables the particles to deliver additional negative charge to the fabric therefore decreasing the deposition tendency of soils.
It would appear that it is particularly advantageous to use nanoparticles for cotton treatment which are close to the pore size of the cellulosic region of the cotton fibre (5–9 nm) and which have a negative Zeta potential at pH 8. While these negatively charged particles are naturally repelled from the fibre surface it is believed that their nano-scale dimensions are small enough that the particles can enter the pores of the fibre and become physically trapped.
Further benefits of the inventions relate to the mechanical properties of fabrics treated with the composition. The nanoparticles are believed to cause an increase in the flexural rigidity of the fabric, which enhances the fibre resistance to creasing. In addition, there are tactile benefits, believed to be associated with a reduction in friction. It is envisaged that such a reduction in friction would have secondary benefits, as a reduction in fibre-fibre friction is believed to prevent fibre damage and therefore reduce pilling and loss of colour.
While the mechanism why the invention works remains speculative, to some extent the present invention also extends to nano-composite cellulosic material obtainable by the method of the invention. Such a material may be in the form of a yarn or in the form of a cloth, or in the form of a finished garment.
As noted above, the nanoparticles are organically modified, inorganic nanoparticles. Preferably these are organically modified siloxanes. Suitable molecules include polyhedral oligomeric silsesquioxane (POSS) species. Preferred POSS species are of the general formula:
(R 1 ) m (—OH) n —O h Si g
Wherein h=3a, g=2a (for a=4 or 6), m+n=g. Preferably, R1 is independently selected from C1–C6 alkyl, aryl or cycloalkyl, phenyl, O − , trifluoropropyl, trimethylsiloxy, phenyl ethyl.
Ionic R1 groups are preferred, particularly, for the reasons given above ones which bear a negative charge. More preferably the materials are water soluble or dispersible.
In a preferred embodiment the nanoparticles comprise octa-trimethylamine POSS (C 32 H 96 N 8 O 20 Si 8 —CAS registry number [69667-29-4]). Suitable counter-ions include quaternary ammonium ions such as NMe 4 + .
A range of POSS materials are available in the marketplace as Nanostructured™ Chemicals from the Hybrid Plastics company (www.hybridplastics.com).
DETAILED DESCRIPTION OF THE INVENTION
Various preferred and/or optional features of the product and method aspects of the present invention are described in further detail below. As used elsewhere in the specification all percentages are percentages by weight unless the context demands otherwise.
Product Form:
The composition of the invention may be in the form of a liquid, solid (e.g. powder or tablet), a gel or paste, spray, stick or a foam or mousse. Examples include a soaking product, a rinse treatment (e.g. conditioner or finisher) or a main-wash product.
Liquid compositions may also include an agent which produces a pearlescent appearance, e.g. an organic pearlising compound such as ethylene glycol distearate, or inorganic pearlising pigments such as microfine mica or titanium dioxide (TiO 2 ) coated mica. Liquid compositions may be in the form of emulsions or emulsion precursors thereof.
Surfactants:
The surfactant may be chosen from soap and non-soap anionic, cationic, nonionic, amphoteric and zwitterionic detergent active compounds, and mixtures thereof.
Surfactants can assist with the delivery of hydrophobic nanoparticles, particularly so-called linear hybrid monomers.
An example of such a linear hybrid monomer is the molecular silica sold under the trade name ‘iso-octyl POSS cage mixture’, whose chemical formula is C 64 H 88 O 12 Si 8 . These nanoparticles are intrinsically insoluble in water due to the iso-octyl chains covalently bonded to the silica structure.
Many suitable surfactants are available and are fully described in the literature, for example, in “Surface-Active Agents and Detergents”, Volumes I and II, by Schwartz, Perry and Berch (Wiley Interscience).
The preferred surfactants that can be used are soaps and synthetic non-soap anionic and nonionic compounds.
Anionic surfactants are well-known to those skilled in the art. Examples include alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyl chain length of C 8 –C 15 ; primary and secondary alkylsulphates, particularly C 8 –C 15 primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred.
Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the C 8 –C 20 aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the C 10 –C 15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkylpolyglycosides, glycerol monoethers, and polyhydroxyamides (glucamide).
Cationic surfactants that may be used include quaternary ammonium salts of the general formula R 1 R 2 R 3 R 4 N + X − wherein the R groups are independently hydrocarbyl chains of C 1 –C 22 length, typically alkyl, hydroxyalkyl or ethoxylated alkyl groups, and X is a solubilising cation (for example, compounds in which R 1 is a C 8 –C 22 alkyl group, preferably a C 8 –C 10 or C 12 –C 14 alkyl group, R 2 is a methyl group, and R 3 and R 4 , which may be the same or different, are methyl or hydroxyethyl groups); and cationic esters (for example, choline esters) and pyridinium salts.
The total quantity of detergent surfactant in the composition is suitably from 0.1 to 60 wt % e.g. 0.5–55 wt %, such as 5–50 wt %.
Preferably, the quantity of anionic surfactant (when present) is in the range of from 1 to 50% by weight of the total composition. More preferably, the quantity of anionic surfactant is in the range of from 3 to 35% by weight, e.g. 5 to 30% by weight.
Preferably, the quantity of nonionic surfactant when present is in the range of from 2 to 25% by weight, more preferably from 5 to 20% by weight.
Amphoteric surfactants may also be used, for example amine oxides or betaines.
Viscous liquid nanoparticle containing material can be heated, preferably to a temperature greater than 60 Celsius to obtain a significant drop in viscosity. This can then be admixed with a surfactant containing solution, preferably under high shear, to obtain a dispersion. Symperonic™ A7 (C13E6.5) is a suitable surfactant.
This concentrated dispersion can be either added as is in a final liquid detergent formulation or can be further processed (i.e., spray drying) to incorporate the hydrophobic nanoparticles load into a powder detergent formulation.
Alternative routes to deliver the hydrophobic nanoparticles is by mixing the viscous molecular silica with a suitable oil, which may be a perfume oil, that would serve as a carrier.
Builders:
The compositions may suitably contain from 10 to 70%, preferably from 15 to 70% by weight, of detergency builder. Preferably, the quantity of builder is in the range of from 15 to 50% by weight.
The detergent composition may contain as builder a crystalline aluminosilicate, preferably an alkali metal aluminosilicate, more preferably a sodium aluminosilicate.
The aluminosilicate may generally be incorporated in amounts of from 10 to 70% by weight (anhydrous basis), preferably from 25 to 50%. Aluminosilicates are materials having the general formula:
0.8–1.5M 2 O.Al 2 O 3 .0.8–6SiO 2
where M is a monovalent cation, preferably sodium. These materials contain some bound water and are required to have a calcium ion exchange capacity of at least 50 mg CaO/g. The preferred sodium aluminosilicates contain 1.5–3.5 SiO 2 units in the formula above. They can be prepared readily by reaction between sodium silicate and sodium aluminate, as amply described in the literature.
Alternatively, or additionally to the aluminosilicate builders, phosphate builders may be used.
Textile Softening and/or Conditioner Compounds:
If the composition of the present invention is in the form of a textile conditioner composition, the surfactant will be a textile softening and/or conditioning compound (hereinafter referred to as “textile softening compound”), which may be a cationic or nonionic compound.
The softening and/or conditioning compounds may be water insoluble quaternary ammonium compounds. The compounds may be present in amounts of up to 8% by weight (based on the total amount of the composition) in which case the compositions are considered dilute, or at levels from 8% to about 50% by weight, in which case the compositions are considered concentrates.
Compositions suitable for delivery during the rinse cycle may also be delivered to the textile in the tumble dryer if used in a suitable form. Thus, another product form is a composition (for example, a paste) suitable for coating onto, and delivery from, a substrate e.g. a flexible sheet or sponge or a suitable dispenser during a tumble dryer cycle.
Suitable cationic textile softening compounds are substantially water-insoluble quaternary ammonium materials comprising a single alkyl or alkenyl long chain having an average chain length greater than or equal to C 20 . More preferably, softening compounds comprise a polar head group and two alkyl or alkenyl chains having an average chain length greater than or equal to C 14 . Preferably the textile softening compounds have two, long-chain, alkyl or alkenyl chains each having an average chain length greater than or equal to C 16 .
Most preferably at least 50% of the long chain alkyl or alkenyl groups have a chain length of C 18 or above. It is preferred if the long chain alkyl or alkenyl groups of the textile softening compound are predominantly linear.
Quaternary ammonium compounds having two long-chain aliphatic groups, for example, distearyldimethyl ammonium chloride and di(hardened tallow alkyl) dimethyl ammonium chloride, are widely used in commercially available rinse conditioner compositions. Other examples of these cationic compounds are to be found in “Surface-Active Agents and Detergents”, Volumes I and II, by Schwartz, Perry and Berch. Any of the conventional types of such compounds may be used in the compositions of the present invention.
The textile softening compounds are preferably compounds that provide excellent softening, and are characterised by a chain melting Lβ to Lα transition temperature greater than 25° C., preferably greater than 35° C., most preferably greater than 45° C. This Lβ to Lα transition can be measured by DSC as defined in “Handbook of Lipid Bilayers”, D Marsh, CRC Press, Boca Raton, Fla., 1990 (pages 137 and 337).
Substantially water-insoluble textile softening compounds are defined as textile softening compounds having a solubility of less than 1×10 −3 wt % in demineralised water at 20° C. Preferably the textile softening compounds have a solubility of less than 1×10 −4 wt %, more preferably less than 1×10 −8 to 1×10 −6 wt %.
Especially preferred are cationic textile softening compounds that are water-insoluble quaternary ammonium materials having two C 12-22 alkyl or alkenyl groups connected to the molecule via at least one ester link, preferably two ester links. Di(tallowoxyloxyethyl)dimethyl ammonium chloride and/or its hardened tallow analogue are especially preferred of the compounds of this type. Other preferred materials include 1,2-bis(hardened tallowoyloxy)-3-trimethylammonium propane chloride. Their methods of preparation are, for example, described in U.S. Pat. No. 4,137,180 (Lever Brothers Co). Preferably these materials comprise small amounts of the corresponding monoester as described in U.S. Pat. No. 4,137,180, for example, 1-hardened tallowoyloxy-2-hydroxy-3-trimethylammonium propane chloride.
Other useful cationic softening agents are alkyl pyridinium salts and substituted imidazoline species. Also useful are primary, secondary and tertiary amines and the condensation products of fatty acids with alkylpolyamines.
The compositions may alternatively or additionally contain water-soluble cationic textile softeners, as described in GB 2 039 556B (Unilever).
The compositions may comprise a cationic textile softening compound and an oil, for example as disclosed in EP-A-0829531.
Nonionic softeners include Lβ phase forming sugar esters (as described in M Hato et al Langmuir 12, 1659, 1666, (1996)) and related materials such as glycerol monostearate or sorbitan esters. Often these materials are used in conjunction with cationic materials to assist deposition (see, for example, GB 2 202 244). Silicones are used in a similar way as a co-softener with a cationic softener in rinse treatments (see, for example, GB 1 549 180). The compositions may also suitably contain a nonionic stabilising agent. Suitable nonionic stabilising agents are linear C 8 to C 22 alcohols alkoxylated with 10 to 20 moles of alkylene oxide, C 10 to C 20 alcohols, or mixtures thereof.
Advantageously the nonionic stabilising agent is a linear C 8 to C 22 alcohol alkoxylated with 10 to 20 moles of alkylene oxide. Preferably, the level of nonionic stabiliser is within the range from 0.1 to 10% by weight, more preferably from 0.5 to 5% by weight, most preferably from 1 to 4% by weight. The mole ratio of the quaternary ammonium compound and/or other cationic softening agent to the nonionic stabilising agent is suitably within the range from 40:1 to about 1:1, preferably within the range from 18:1 to about 3:1.
The composition can also contain fatty acids, for example C 8 to C 24 alkyl or alkenyl monocarboxylic acids or polymers thereof. Preferably saturated fatty acids are used, in particular, hardened tallow C 16 to C 18 fatty acids. Preferably the fatty acid is non-saponified, more preferably the fatty acid is free, for example oleic acid, lauric acid or tallow fatty acid. The level of fatty acid material is preferably more than 0.1% by weight, more preferably more than 0.2% by weight. Concentrated compositions may comprise from 0.5 to 20% by weight of fatty acid, more preferably 1% to 10% by weight. The weight ratio of quaternary ammonium material or other cationic softening agent to fatty acid material is preferably from 10:1 to 1:10.
Other Components
Compositions according to the invention may comprise soil release polymers such as block copolymers of polyethylene oxide and terephthalate.
Other optional ingredients include emulsifiers, electrolytes (for example, sodium chloride or calcium chloride) preferably in the range from 0.01 to 5% by weight, pH buffering agents, and perfumes (preferably from 0.1 to 5% by weight).
Further optional ingredients include non-aqueous solvents, fluorescers, colourants, hydrotropes, antifoaming agents, enzymes, optical brightening agents, and opacifiers.
Suitable bleaches include peroxygen bleaches. Inorganic peroxygen bleaching agents, such as perborates and percarbonates are preferably combined with bleach activators. Where inorganic peroxygen bleaching agents are present the nonanoyloxybenzene sulphonate (NOBS) and tetra-acetyl ethylene diamine (TAED) activators are typical and preferred.
Suitable enzymes include proteases, amylases, lipases, cellulases, peroxidases and mixtures thereof.
In addition, compositions may comprise one or more of anti-shrinking agents, anti-wrinkle agents, anti-spotting agents, germicides, fungicides, anti-oxidants, UV absorbers (sunscreens), heavy metal sequestrants, chlorine scavengers, dye fixatives, anti-corrosion agents, drape imparting agents, antistatic agents and ironing aids. The lists of optional components are not intended to be exhaustive.
Lubricants and other ‘wrinkle release’ agents are a particularly preferred optional component of compositions according to the invention.
In order that the invention may be further and better understood it will be described below with reference to several non-limiting examples.
EXAMPLE 1
In this and in the following examples polyhedral oligomeric silsesquioxane (POSS), size 3–7 nm was used, unless stated otherwise. This material is available from Hybrid Plastics (www.hybridplastics.com).
In a model (bottle) main-wash, woven cotton sheeting and Poplin fabrics (fabric weight 2.7 g) were treated at pH 8 in an aqueous dispersion of POSS in the absence of surfactants. Experiments were performed at a 1:8 cloth to liquor ratio. Four loading levels of POSS on weight of fabric (owf) were used: 0.5% owf, 1% owf, 2% owf and 5% owf. The samples were placed in a water-bath at 40° C. and were shaken for 40 min.
Particle deposition on cloths (mg silica/g fabric) was quantified by Inductively Coupled Plasma (ICP) element analysis.
After being washed and dried the cloths were ironed, conditioned at relative humidity 65% and 20° C. for 24 h and their mechanical properties: crease recovery angle (CRA) and bending length (BL) were further measured. CRA technique gives information about wrinkle resistance and recovery properties of fabrics and the bending length for their flexural rigidity.
Nano-silica (3–7 nm) at 5% owf gave a significant increase of the rigidity (˜35% increase) with both fabrics.
Deposited silica levels [0.6–1.1 mg silica/g fabric] gave best CRA benefits (˜18% improvement). Any further increase in the deposited silica led to a decrease of the CRA. This could be a result of particle aggregation and full plugging of pores which impedes the recovery of already formed wrinkles.
SEM-Si mapping (EPMA) of cross-sections of the nano-silica treated fabric demonstrated that the silica is positioned inside the wall of the fibre-mostly in the cellulose porous part and less in the lumen.
EXAMPLE 2
Cotton sheeting fabrics were washed according the protocol described in example 1 above with nano-silica present at 2% owf. For comparison, colloidal silica of significantly larger size and different morphology was also used. After drying the same monitors were soiled with low concentrations of carbon black and Bandy black clay. Further cloths were tested for reflectance at 460 nm. Results are shown in Table 1 below.
TABLE 1
Cotton sheeting fabrics-redeposition study
Reflectance
Fabric Sample
460 nm
Untreated cotton
89 (0.16)
Untreated + Soiled with Carbon black
77 (1.03)
Untreated + Soiled with clay
83 (0.51)
Cotton treated (−ve charged) nanosilica
88 (0.14)
Treated + Soiled with Carbon black
82 (0.83)
Treated + Soiled with clay
85 (0.75)
Cotton treated (+ve charged) silica (50 nm)
88 (0.22)
Treated + Soiled with Carbon black
78 (1.29)
Treated + Soiled with clay
83 (0.82)
Data in brackets show 95% confidence.
Both clay and carbon black are typical laundry particulate soils. It is believed that carbon black and Bandy black clay are poly-disperse systems of wide size distribution (1 nm–2 microns). From table 1 (upper triad of results) it can be seen that the reflectance is reduced significantly by soiling with both carbon black and clay (max. difference=12).
The middle triad of results shows only a small decrease in the reflectance of treated monitors before and after soiling (max. difference=6). It is believed that the fabric treated with nano-silica can be considered as a nano-composite textile and that nanoparticles inside the fibre pores prevent soil deposition inside the fibre. In addition the electrostatic repulsion between negatively charged silica and the soil particles (also negatively charged) results in less soiling.
In the third triad of results colloidal silica of size 50 nm was used as a comparison. This silica is believed to be positively charged and to modify the fibre surface without penetrating inside it. It can be seen that the reflectance was significantly changed as a result of soiling.
EXAMPLE 3
Fabric saturated with a test solution was forced between pressure controlled rollers (the padder) to squeeze excess solution from the fabric, leaving the desired amount of material on the fabric. Fabrics were line-dried before testing.
Mechanical properties (stiffness and elasticity) of cotton sheeting fabrics padded with 2% owf POSS nano-silica were tested using Kawabata shear technique. This measures inter-fibre friction and gives information about the fabric shear stiffness (G) and shear elasticity (2HG5). Nano-particulate silica treated cotton sheeting fabrics show increased stiffness (+25%) and reduced elasticity (−20%).
Surface friction coefficient was measured for cotton sheeting treated with nano-silica and found (using the Eldredge Tribometer) to be substantially lower than that of untreated fabric under both dry and wet conditions.
EXAMPLE 4
The damage of blue drill cotton padded with 2% owf POSS nano-silica was assessed through SEM analysis of fabric fibrillation and measurement of the fabric-fabric friction coefficient using the Eldredge Tribometer and compared to the damage of drill cotton both untreated and treated with other lubricant materials.
The comparison lubbricant was formed by admixing 28 g of glycerol monoisostearate (Prisorine™ 2040, Uniquema, Wirral, UK) with 12 g of polydimethylsiloxane PEG isostearate blend (Silwax™ DMC-IS, Siltech, Ontario, Canada).
The surface friction measured at wet conditions (wash liquor, pH 10) for the drill cotton treated with nano-silica was significantly lower than the friction of untreated cloth and also lower than those of the fabric treated with the comparison lubricant (also at 2% owf).
EXAMPLE 5
Preparation of a Surfactant Containing Composition
This example was performed with ‘iso-octyl POSS cage mixture’ (ex Hybrid Plastics, whose chemical formula is C 64 H 88 O 12 Si 8 . The viscous liquid comprising the nanoparticles was heated to a temperature slightly greater than 60 Celsius at which point a significant drop in viscosity is observed.
0.5 g of the heated liquid containing the hydrophobic nanoparticles was added drop-wise to a container with 20 ml of a concentrated surfactant solution (10 g/l) of Symperonic A7 (C13E6.5) in water. The liquid was stirred using a universal electronic stirrer (Heidolph RZR 2051, Heidolph Instruments GmbH & Co. KG, Schwabach, Germany) at 1500–2000 rpm for a total of 5 to 10 minutes. A concentrated emulsion of droplets containing the hydrophobic nanoparticles in water is obtained.
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Laundry treatment compositions comprising 0.001–5 wt % of monomeric hybrid organic/inorganic nanoparticles having a particle size of 1–10 nm and 10–95% surfactant give ease of wash benefits to soiled fabric as well as prevention of adsorption of particulate soils.
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CROSS REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority based on U.S. Provisional Application, Ser. No. 62/323,177, filed Apr. 15, 2016, entitled SANITIZE-AWARE DRAM CONTROLLER, which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] Dynamic random access memory (DRAM) is ubiquitous in modern computing systems. DRAM is ubiquitous because of its relatively low cost, high capacity/density and high speed. The density benefit largely derives from the fact that each cell for storing a data bit requires only a capacitor and single transistor. This is significantly less hardware than required per cell for a static random access memory (SRAM), for example. However, the storage of the data bit on the capacitor of the cell implies a power consumption cost. This is because the capacitor charge may leak over time, causing the cell to lose its value. Consequently, the capacitor must be “refreshed” periodically to retain its value. This involves reading the current value from the cell and writing it back to the cell to “refresh” its value. The refresh operation consumes additional power over other memory technologies that do not require refresh. Refresh may contribute to a significant percentage of the energy consumption of a DRAM, e.g., approximately 20%, and may degrade system performance, e.g., approximately 30%, depending upon the demand for DRAM access by the system.
[0003] U.S. Pat. No. 5,469,559, issued to one of the present co-inventors, describes a memory controller and method for refreshing a selected portion of a DRAM that does not contain valid data. This may reduce the amount of power consumed by refreshing, which is needless for invalid data.
[0004] The present inventors provide embodiments of a DRAM controller that provide further benefits. The additional benefits are enjoyed primarily by recognition by the inventors of the fact that many operating systems “sanitize” deallocated memory by writing zeroes to it in order to increase system security by preventing a hacker and/or the next user to whom the memory is allocated from seeing the data of the first user, for example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a block diagram illustrating a computing system.
[0006] FIG. 2 is a block diagram illustrating a computing system according to an alternate embodiment.
[0007] FIGS. 3 through 5 are flowcharts illustrating operation of the system.
[0008] FIG. 6 is a flowchart illustrating operation of the system to perform selective refresh of sanitized DRAM blocks according to one embodiment.
[0009] FIG. 7 is a block diagram illustrating a sanitize detection hardware (SDH) instance.
[0010] FIG. 8 is a flowchart illustrating operation of the DRAM controller to detect that a DRAM block is to be sanitized by employing the SDH instances of FIG. 7 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
Glossary
[0011] A block of a DRAM is one or more units of storage in the DRAM for which the DRAM controller can selectively enable or disable refreshing. For example, what is commonly referred to as a “row” of a data RAM 122 is refreshable. For some DRAMs, a row is 512 bytes of storage, as an example.
[0012] To sanitize a block of DRAM means to clear all locations in the block to a zero value.
[0013] Referring now to FIG. 1 , a block diagram illustrating a computing system 100 is shown. The computing system 100 includes a processor 102 , a DRAM 104 , a DRAM controller 103 connecting the processor 102 to the DRAM 104 , and other bus masters 106 that access the DRAM 104 via the DRAM controller 103 , e.g., bus-mastering I/O devices. The processor 102 may be a multi-core processor. The processor 102 executes programs, including system software, such as an operating system and/or system firmware, such as Basic Input/Output System (BIOS) or extensible firmware, as well as utilities and application programs. The DRAM 104 is arranged as a plurality of DRAM blocks 142 . The system software, among other things, sanitizes portions of the DRAM 104 , including entire DRAM blocks 142 . Many operating systems sanitize memory in the granularity of a page whose size is determined according to the virtual memory system supported by the processor 102 . For example, common page sizes are 4 KB, 64 KB, 1 MB, 16 MB, 256 MB, 1 GB and 2 GB.
[0014] The DRAM controller 103 regards one or more units of storage in the DRAM 104 for which the DRAM controller can selectively enable or disable refreshing, for example, a row of the DRAM 104 , as DRAM block 142 . In some embodiments, the size of a DRAM block 142 corresponds to the size of the smallest pages supported by the processor's 102 virtual memory system. For example, if the unit of storage for which the DRAM controller can selectively enable or disable refreshing is a 512 byte row and the smallest page size supported by the processor 102 is 4 KB, then the DRAM controller 103 regards 8 contiguous rows of DRAM 104 as a DRAM block 142 .
[0015] The DRAM controller 103 includes a plurality of sanitize flags 132 , also referred to as sanitize bits 132 , and a sanitize controller 134 . In one embodiment, the DRAM controller 103 includes a sanitize bit 132 for each corresponding DRAM block 142 of the DRAM 104 .
[0016] In an alternate embodiment, referred to herein as the sanitize range embodiment, each sanitize bit 132 has a corresponding range register which together comprise a sanitize pair. The range register holds an address and a count to specify a range of contiguous DRAM blocks 142 . The address specifies the first, or starting, DRAM block 142 in the range, and the count specifies the number of contiguous DRAM blocks 142 in the range. If the sanitize bit 132 is set, then the range of DRAM blocks 142 specified in the corresponding range register is considered sanitized, as described in more detail below. The sanitize controller 134 treats the plurality of sanitize pairs as a pool from which the sanitize controller 134 can allocate for a range of contiguous DRAM blocks 142 (e.g., at block 304 of FIG. 3 ) and into which the DRAM controller 103 can deallocate (e.g., at block 508 of FIG. 5 ). If the sanitize bit 132 is set this indicates the sanitize pair is allocated, and if the sanitize bit 132 is clear this indicates the sanitize pair is free for allocation.
[0017] Referring now to FIG. 2 , a block diagram illustrating a computing system 100 according to an alternate embodiment is shown. The computing system 100 of FIG. 2 is similar to the computing system 100 of FIG. 1 and includes similar elements. However, in the computing system 100 of FIG. 2 , the DRAM controller 103 is integrated into the processor 102 . More specifically, the processor 102 includes a ring bus 226 to which the DRAM controller 103 is connected. The processor 102 also includes a plurality of processing cores 222 connected to the ring bus 226 . The processor 102 also includes a last-level cache (LLC) 224 connected to the ring bus 226 which is shared by the cores 222 . Preferably, the DRAM controller 103 , LLC 224 and each core 222 has an associated ring stop that connects it to the ring bus 226 . Finally, the processor 102 includes an I/O ring stop 228 that connects the I/O devices 106 to the ring bus 226 .
[0018] Referring now to FIG. 3 , a flowchart illustrating operation of the system 100 is shown. Flow begins at block 302 .
[0019] At block 302 , the DRAM controller 103 determines that a DRAM block 142 is to be sanitized. In one embodiment, the system software informs the DRAM controller 103 that a DRAM block 142 is to be sanitized, as described below with respect to FIG. 6 , for example. In another embodiment, the DRAM controller 103 includes hardware that makes the determination by monitoring zero-valued writes to DRAM blocks 142 , as described below with respect to FIGS. 7 and 8 , for example. Other embodiments for determining that a DRAM block 142 is to be sanitized are also contemplated. Flow proceeds to block 304 .
[0020] At block 304 , the DRAM controller 103 sets the sanitize bit 132 associated with the DRAM block 142 determined at block 302 . Additionally, the DRAM controller 103 disables refreshing of the DRAM block 142 . In the sanitize range embodiment, the DRAM controller 103 allocates a sanitize pair, sets the sanitize bit 132 , and populates the range register with the address of the first DRAM block 142 in the range and the count with the number of DRAM blocks 142 in the range. Additionally, the DRAM controller 103 disables refreshing of all the DRAM blocks 142 in the range. Flow ends at block 304 .
[0021] Referring now to FIG. 4 , a flowchart illustrating operation of the system 100 is shown. Flow begins at block 402 .
[0022] At block 402 , the DRAM controller 103 receives a request to read from a location of the DRAM 104 . The location implicates a DRAM block 142 , i.e., is within a DRAM block 142 based on its address. Flow proceeds to decision block 404 .
[0023] At decision block 404 , the DRAM controller 103 determines whether the sanitize bit 132 corresponding to the implicated DRAM block 142 is set. If so, flow proceeds to block 408 ; otherwise, flow proceeds to block 406 . In the sanitize range embodiment, the sanitize controller 134 determines that the address of the read request falls into the range specified in the range register of a sanitize pair whose sanitize bit 132 is set.
[0024] At block 406 , the DRAM controller 103 reads the specified location from the DRAM 104 and returns the data that was read, i.e., according to normal operation of the DRAM controller 103 . Flow ends at block 406 .
[0025] At block 408 , the DRAM controller 103 does not read the DRAM 104 and instead returns a zero value to the read request. This is because the DRAM block 142 implicated by the read request was determined to be sanitized at decision block 404 . Flow ends at block 408 .
[0026] Advantages of not reading the DRAM when the block is sanitized (e.g., at block 408 ) are: (1) less power may be consumed because the DRAM block need not be refreshed to maintain a zero value; (2) less power may be consumed because the DRAM is not accessed to read the data, even though software requested to read the data; and (3) performance may be improved because the latency of the read request is shorter because the DRAM does not have to be accessed to read the requested data, all of which is possible because the desired value of the data is known to be zero.
[0027] Referring now to FIG. 5 , a flowchart illustrating operation of the system 100 is shown. Flow begins at block 502 .
[0028] At block 502 , the DRAM controller 103 receives a request to write data to a location of the DRAM 104 . More specifically, the DRAM controller 103 determines that the data to be written has a non-zero value. The location implicates a DRAM block 142 , i.e., is within a DRAM block 142 based on its address, or implicates a range of DRAM blocks 142 in the sanitize range embodiment. In an alternate embodiment, the DRAM controller 103 does not check to see whether the data to be written is non-zero, but instead performs the operations of FIG. 5 regardless of the data value. If the DRAM controller 103 receives a request to write data to a location of the DRAM 104 that has a zero value, then if the sanitize bit 132 is set the DRAM controller 103 does not write to the DRAM 104 , whereas if the sanitize bit 132 is clear the DRAM controller 103 writes the zero value to the specified location of the DRAM 104 . Flow proceeds to decision block 504 .
[0029] At decision block 504 , the DRAM controller 103 determines whether the sanitize bit 132 corresponding to the implicated DRAM block 142 or range of DRAM blocks 142 is set. If so, flow proceeds to block 508 ; otherwise, flow proceeds to block 506 . In the sanitize range embodiment, the sanitize controller 134 determines that the address of the write request falls into the range specified in the range register of a sanitize pair whose sanitize bit 132 is set.
[0030] At block 506 , the DRAM controller 103 writes the specified data to the specified location of the DRAM 104 , i.e., according to normal operation of the DRAM controller 103 . Flow ends at block 506 .
[0031] At block 508 , the DRAM controller 103 clears the sanitize bit 132 corresponding to the implicated DRAM block 142 . Additionally, the DRAM controller 103 re-enables refreshing for the implicated DRAM block 142 or the range of DRAM blocks 142 implicated by the range register in the sanitize range embodiment. Still further, the DRAM controller 103 writes the specified data to the specified location of the DRAM 104 . Finally, the DRAM controller 103 writes zeroes to all the locations of the DRAM block 142 or implicated range of DRAM blocks 142 other than the location specified by the write request. Flow ends at block 508 .
[0032] Advantages of waiting to write the other locations of the block to zero values until the first non-zero write to the sanitized block are: (1) less power may be consumed because the DRAM block is not being refreshed for an additional amount of time than it would be if refreshing was begun as soon as the operating system indicated the block was allocated (e.g., as in U.S. Pat. No. 5,469,559), and in some cases it may be a significant amount of time before software writes to the block after it allocates the block; and (2) the operating system does not have to perform all the writes of zero to the block, which involves the processor 102 executing instructions, which may be on the order of tens to hundreds, to write the zeroes to the block. This latter consideration has the resulting benefits of: (a) less power may be consumed by the processor 102 because it does not have to execute the many write instructions; (b) system performance may be improved because the processor 102 does not have to execute the many write instructions and is therefore free to execute other instructions; and (c) system performance may be improved because the DRAM controller 103 performs the zero writes to the block without the extra latency that would be involved if the processor 102 had to execute the write instructions and then make the write requests to the DRAM controller 103 . It should be understood that the second benefit (2) may not be realized by the sanitize detection hardware (SDH) embodiment of FIGS. 7 and 8 .
[0033] Referring now to FIG. 6 , a flowchart illustrating operation of the system 100 to perform selective refresh of sanitized DRAM blocks 142 according to one embodiment is shown. Flow begins at block 602 .
[0034] At block 602 , system software (e.g., the operating system or other executive) decides to sanitize a DRAM block 142 . For example, some operating systems provide system calls, such as bzero( ) and memset( ) found in the UNIX operating system and related operating systems such as Mac OS X and later versions of Microsoft Windows, that can be invoked to sanitize a sequence of memory locations, i.e., a specified number of contiguous memory locations beginning at a specified memory address. Conventionally, the routines that implement these system calls perform a series of writes of the value zero to all the memory locations in the specified sequence. In one embodiment, the routine that implements the system call is modified take advantage of the capabilities of the DRAM controller 103 . More specifically, the routine checks to see whether one or more entire DRAM blocks 142 are included by the sequence of memory locations. If so, instead of conventionally performing the series of zero-valued writes to the included blocks 142 , the routine writes to the DRAM controller 103 to request it to sanitize the included blocks 142 , as described with respect to block 604 . Flow proceeds to block 604 .
[0035] At block 604 , the system software writes the address of the block 142 to be sanitized to the DRAM controller 103 . Preferably, the DRAM controller 103 includes a control register that receives the address. That is, the control register is writeable by system software running on the system 100 (e.g., on the processor 102 ) that includes the DRAM 104 and DRAM controller 103 . In the sanitize range embodiment, the system software writes both the address and the count of DRAM blocks 142 of the range. Flow proceeds to block 606 .
[0036] At block 606 , the DRAM controller 103 performs the operations of FIG. 3 for the specified block 142 or range of blocks 142 , namely setting the sanitize bit 132 associated with the block 142 or range of blocks 142 and disabling refresh for the block 142 or range of blocks 142 . Flow ends at block 606 .
[0037] Referring now to FIG. 7 , a block diagram illustrating a sanitize detection hardware (SDH) instance 700 is shown. In one embodiment, the DRAM controller 103 includes a plurality of SDH instance 700 from which the DRAM controller 103 allocates (e.g., at block 806 of FIG. 8 ) and into which the DRAM controller 103 deallocates (e.g., at block 818 of FIG. 8 ). The SDH instance 700 includes a valid bit 702 , a bitmap 704 , an address register 708 , and control logic 706 . The valid bit 702 indicates the SDH instance 700 is allocated if true and indicates the SDH instance 700 is free if false. The bitmap 704 includes a bit for each location of the DRAM block 142 whose address is held in the address register 708 . In various embodiments, a location in the DRAM block 142 corresponds to an aligned byte, a 16-bit half-word, a 32-bit word, a 64-bit double-word, a 128-bit quad-word, or a 256-bit octa-word. In one embodiment, a location corresponds to an aligned cache line, e.g., of a last-level cache of the processor 102 . The control logic 706 performs operations associated with reading and updating the valid bit 702 , bitmap 704 and address register 708 , such as those described below with respect to FIG. 8 .
[0038] Referring now to FIG. 8 , a flowchart illustrating operation of the DRAM controller 103 to detect that a DRAM block 142 is to be sanitized by employing the SDH instances 700 of FIG. 7 is shown. Flow begins at block 802 .
[0039] At block 802 , the DRAM controller 103 receives a request to write data to a location of the DRAM 104 . The location implicates a DRAM block 142 , i.e., is within a DRAM block 142 based on its address, or implicates a range of DRAM blocks 142 in the sanitize range embodiment. Flow proceeds to decision block 804 .
[0040] At decision block 804 , the DRAM controller 103 determines whether a SDH instance 700 has been allocated for the DRAM block 142 or range of DRAM blocks 142 implicated by the write request. More specifically, the DRAM controller 103 determines whether the relevant portion of the read request address matches the address 708 of a valid 702 SDH instance 700 . If so, flow proceeds to decision block 808 ; otherwise, flow proceeds to block 806 .
[0041] At block 806 , the sanitize controller 134 allocates a free SDH instance 700 . Preferably, allocating the SDH instance 700 includes finding a free SDH instance 700 (i.e., whose valid bit 702 is false), initializing the valid bit to true, clearing all bits of the bitmap 704 to zero, and writing the relevant portion of the write request address into the address register 708 . Preferably, if there is no free SDH 700 to allocate, the DRAM controller 103 simply continues normally, i.e., it does not attempt to detect that a block 142 is being sanitized. Flow ends at block 806 .
[0042] At decision block 808 , the sanitize controller 134 determines whether the value to be written is zero. If so, flow proceeds to block 814 ; otherwise, flow proceeds to block 812 .
[0043] At block 812 , the sanitize controller 134 deallocates the SDH instance 700 that was previously allocated for the DRAM block 142 (i.e., at block 806 ). Preferably, deallocating the SDH instance 700 comprises clearing the valid bit 702 , which frees the SDH instance 700 for subsequent allocation. Flow ends at block 812 .
[0044] At block 814 , the sanitize controller 134 sets the bitmap 704 bit associated with the location in the DRAM block 142 written by the request received at block 802 . Flow proceeds to decision block 816 .
[0045] At decision block 816 , the sanitize controller 134 determines whether the bitmap 704 is full, i.e., whether the bitmap 704 has all of its bits set. If so, flow proceeds to block 818 ; otherwise, flow ends.
[0046] At block 818 , the sanitize controller 134 deallocates the SDH instance 700 that was previously allocated for the DRAM block 142 and begins to perform the operations for the DRAM block 142 as described with respect to FIG. 3 because the sanitize controller 134 has determined that the system software has sanitized the DRAM block 142 .
[0047] Other embodiments of an SDH instance are contemplated. In one embodiment, the DRAM controller 103 assumes the series of zero-valued writes to sanitize the block 142 are of fixed size words and begin at the first location in the block 142 . The embodiment does not require the bitmap 704 , but instead requires a register that holds the index of the fixed-size word within the block 142 after the word of the block 142 most recently written with a zero value. During operation, the DRAM controller 103 detects a write of a data value to the first location in a block 142 . If no SDH instance has been allocated for the block 142 and the write is of a zero-valued word of the fixed-size, the DRAM controller 103 allocates an SDH instance. Allocating the SDH instance includes initializing the register to a value of one. If an SDH instance has been allocated for the block 142 , the DRAM controller 103 determines whether the data value is zero and the index of the register matches the index of the current zero-valued write. If not, the DRAM controller 103 deallocates the SDH instance. Otherwise, the DRAM controller 103 determines whether the index of the register is the highest index in the block 142 . If so, the DRAM controller 103 deallocates the SDH instance and performs the operations of FIG. 3 for the block; otherwise, the DRAM controller 103 increments the register.
[0048] While various embodiments of the present invention have been described herein, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant computer arts that various changes in form and detail can be made therein without departing from the scope of the invention. For example, software can enable, for example, the function, fabrication, modeling, simulation, description and/or testing of the apparatus and methods described herein. This can be accomplished through the use of general programming languages (e.g., C, C++), hardware description languages (HDL) including Verilog HDL, VHDL, and so on, or other available programs. Such software can be disposed in any known computer usable medium such as magnetic tape, semiconductor, magnetic disk, or optical disc (e.g., CD-ROM, DVD-ROM, etc.), a network, wire line, wireless or other communications medium. Embodiments of the apparatus and method described herein may be included in a semiconductor intellectual property core, such as a processor core (e.g., embodied, or specified, in a HDL) and transformed to hardware in the production of integrated circuits. Additionally, the apparatus and methods described herein may be embodied as a combination of hardware and software. Thus, the present invention should not be limited by any of the exemplary embodiments described herein, but should be defined only in accordance with the following claims and their equivalents. Specifically, the present invention may be implemented within a processor device that may be used in a general-purpose computer. Finally, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the scope of the invention as defined by the appended claims.
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A controller for controlling a dynamic random access memory (DRAM) comprising a plurality of blocks. A block is one or more units of storage in the DRAM for which the DRAM controller can selectively enable or disable refreshing. The DRAM controller includes flags each for association with a block of the blocks of the DRAM. A sanitize controller determines a block is to be sanitized and in response sets a flag associated with the block and disables refreshing the block. In response to subsequently receiving a request to read data from a location in the block, if the flag is clear, the DRAM controller reads the location and returns data read from it. If the flag is set, the DRAM controller refrains from reading the DRAM and returns a value of zero.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to an overhead installation for transporting people, comprising two overhead carrying cables which are spaced apart from one another and extend in parallel manner on the same level, being stretched taut between two pillars to form a curved running track presenting a deformable sag, and a positively guided, servo-controlled vehicle comprising a passenger compartment, four rollers arranged in the form of a rectangle, with two rollers longitudinally spaced apart from one another running on one of the cables, and two rollers longitudinally spaced apart from one another running on the other cable, to support and guide the passenger compartment of the vehicle running on the curved track, and a connecting device without a hanger arm between the rollers and the passenger compartment to position the passenger compartment longitudinally, transversely, and with respect to the level.
[0002] The expression positively guided, servo-controlled means a certain guiding, without the risk of random movements, and in the telfer car technique more particularly a vehicle without a hanger arm. The invention relates to an installation having a vehicle without a hanger arm, i.e. a vehicle not making use of gravity to maintain its verticality, which runs on carrying cables presenting sags.
STATE OF THE ART
[0003] Overhead cable installations, in particular telfer cars, are generally located in mountainous areas and comprise vehicles equipped with articulated hanger arms which are more or less long according to the slope of the cables and to the length of the cars. The infrastructure of these telfer cars is of considerable size and the car is subjected, in the course of movement, to rocking movements and random rocking which make the use of such telfer cars in an urban environment quite unacceptable.
[0004] The document FR2,575,985 describes an installation with two carrying cables on which four rollers run, the spindles of the rollers being rigidly fixed to the four corners of the vehicle. The vehicle is positively guided, in the acceptance of the term in the present description, but the vehicle follows the curved sagging path of the cables with inclines that are unacceptable for an urban people mover.
[0005] The documents EP0,561,095 and U.S. Pat. No. 4,641,587 concern overhead vehicles suspended on two carrying cables by hanger arm systems. The carrying cables are kept horizontal, in the manner of suspended bridges, by a sizeable infrastructure. It is moreover almost impossible to achieve horizontal tracks with cables. According to the present invention, the carrying cables are simply stretched taut between pillars of smaller height as the vehicle does not have a hanger arm.
[0006] The document US2009/0038499 describes a vehicle having a hanger arm which is formed by cables. The carriage runs on a carrying cable which sags in curved manner and the car is not positively guided, according to the meaning of the present invention, as it is subjected to longitudinal and transverse rocking and swaying movements, unacceptable for an urban people mover.
OBJECT OF THE INVENTION
[0007] The object of the present invention is to enable an overhead installation to be provided, meeting the current requirements of a transport system in an urban environment, in particular movement at high speed, maximum passenger comfort and a light infrastructure. The cabin of the vehicle must not be subjected to any undesirable movement detrimental to the comfort of the passengers, in spite of the sag of the cables. An undesirable movement can be a rocking movement, a variation of level, a vertical acceleration or jerking when passing over a discontinuity of the track.
[0008] In one embodiment, the car or passenger compartment is kept vertical or very slightly inclined whatever the slope, in the longitudinal direction, of the cables on which the rollers run, and whatever the difference of level of the cables in the transverse direction, in particular due to decentring of the transported load and/or the action of a side wind. The term vertical implies a horizontal floor of the car, and the terms vertical and horizontal will henceforth be used indifferently to designate the position of the car.
[0009] According to other implementations of the invention, the car remains at a constant level, jerking is attenuated and the vertical acceleration when passing over the cable support structures is reduced to within acceptable comfort limits.
[0010] The installation according to the invention is characterized in that the four rollers follow the height variations of the cable in space independently, during movement of the vehicle, that said connecting device comprises an individual positive height-adjustable jack for each roller, and that the vehicle comprises a central unit which controls the different individual jacks so as to compensate the height variations of the different rollers, imposed by the cables, during movement on the curved track.
[0011] The expression ‘positive height-adjustable jack’ means that the device transmits the movements faithfully, in servo-controlled manner, with a single height adjustment possibility.
[0012] In one embodiment of the invention, the central unit is controlled by a detector of the incline of the passenger compartment so as to move the different rollers in the heightwise direction to keep the passenger compartment vertical.
[0013] The central unit can also be controlled by a level detector to keep the level of the passenger compartment constant along the whole itinerary and/or by a vertical acceleration detector, in particular when passing over a pillar.
[0014] According to an important development of the invention, the vehicle runs on the carrying cables, its centre of gravity being located above the cables. The infrastructures (pillars and terminals supporting the carrying cables) are thus less high than the value of the height of the car and of the hanger arm compared with the usual installation where the vehicle is suspended on the cables, which is appreciable in terms of insertion in an urban environment, and very economical as far as the cost of said infrastructures is concerned. All the mechanical parts and the accessories of the vehicle can be grouped together underneath the cabin. In the case of traction by a cable, advantageously situated underneath the level of the car, the cable can naturally escape downwards, which has the consequence of only requiring support rollers (to the exclusion of compression rollers, passage of which under the vehicle would give rise to problems, in the same way as passage of the support rollers gives rise to problems for suspended vehicles).
[0015] When the track presents a break of continuity, in particular when passing from cables to rails, an undesirable movement of the passenger compartment is inevitable. In one embodiment, each carrying cable is replaced by a pair of juxtaposed cables and each roller is replaced by a pair of rollers, juxtaposed on one and the same spindle, running on the pair of juxtaposed cables. The cable-rail transitions are staggered longitudinally from one cable to the other so that carrying is always performed by one of the cables of the pair and by the associated roller preventing any jerking when passage takes place. Redundancy of the cables and rollers reduces the risks of accidents, one taking over from the other in case of an incident occurring on a roller or on a carrying cable.
[0016] The vehicle can comprise one or more electric motors (not shown) driving one or more rollers enabling it to be self-driven. When the vehicle is hauled by a hauling cable, the motor takes over when the vehicle is detached from the hauling cable. When this hauling cable is below the running level of the vehicle, the coupling clamp is retractable so that no element of the vehicle is underneath the level of the running rollers to ensure freedom of running of the vehicle in the terminal stations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Other advantages and features of the invention will become more clearly apparent from the following description of different embodiments of the invention, given for non-restrictive example purposes only and represented in the appended drawings, in which:
[0018] FIGS. 1 and 2 are elevational views of a section of an installation, respectively illustrating passage of a vehicle without a trim corrector and passage of a vehicle with trim correction;
[0019] FIGS. 3 and 4 are schematic front and side views of a vehicle according to the invention;
[0020] FIGS. 5 and 6 are side views of the vehicle illustrating correction of a transverse incline;
[0021] FIGS. 7 to 9 are front views showing the successive positions of the vehicle when passing over a pillar;
[0022] FIGS. 10 to 12 are detailed elevation views of a support damper of a roller, respectively when passing a short support;
[0023] FIGS. 13 and 14 are schematic front and side views of a vehicle according to an alternative embodiment of the invention;
[0024] FIGS. 15 and 16 are elevational views of an installation respectively illustrating the level of the carrying cable of a line equipped with a conventional vehicle and that of a line equipped with a vehicle according to FIGS. 13 and 14 ;
[0025] FIGS. 17 and 18 are similar views to FIGS. 3 and 4 illustrating a simplified alternative embodiment;
[0026] FIG. 19 is a similar view to FIG. 2 showing a trajectory correction device;
[0027] FIG. 20 is a similar view to FIG. 4 of an improvement of the invention;
[0028] FIG. 21 is a partial perspective view of the vehicle according to FIG. 20 illustrating passage over a break of continuity of the track;
[0029] FIG. 22 is a schematic front view of a vehicle according to an alternative embodiment of the invention;
[0030] FIGS. 23 and 24 are similar views to FIGS. 13 and 14 illustrating running of a vehicle, according to the invention, in a terminal with the coupling clamps retracted.
[0031] The same reference numerals are used in the different figures to designate similar or identical parts.
DETAILED DESCRIPTION OF THE INVENTION
[0032] In FIGS. 1 and 2 , an overhead track 10 of an urban transport installation comprises two carrying cables 11 , 12 stretched taut between pillars 13 , and vehicles 14 , 15 of almost rectangular shape having a roller 16 - 19 at each of their four corners for running on cables 11 , 12 , one pair of rollers 16 , 17 at the front and one pair of rollers 18 , 19 at the rear. Each roller 16 - 19 is supported by a slide block 20 ( FIG. 6 ) movable in a vertical slide guide 21 fixed over the whole height of vehicle 15 . Each roller 16 - 19 has associated therewith a jack 22 (represented schematically by an arrow) for heightwise movement, and all the jacks 22 are connected to a central unit of a trim corrector 23 receiving information from an inclinometer 24 schematically represented by a pendulum.
[0033] Operation is clearly apparent from FIGS. 1 and 2 . In FIG. 1 , vehicle 14 does not comprise a trim corrector and rollers 16 - 19 are rigidly fixed to the vehicle. Between the two pillars 13 , the vehicle follows the sagging trajectory of cables 11 , 12 , rocking towards the front and then towards the rear, which is not acceptable.
[0034] According to the invention, represented in FIG. 2 , pendulum 24 detects the frontwards rocking of vehicle 15 and sends a movement order of the front rollers 16 , 17 in the downwards direction to compensate the descending slope of cables 11 , 12 . Subsequently a relative displacement of front rollers 16 , 17 with respect to rear rollers 18 , 19 enables vehicle 15 to be kept substantially vertical, compensating the longitudinal rocking corresponding to the sag of the cables. Floor 25 remains horizontal throughout the travel between the two pillars. In the example represented in FIG. 2 , floor 25 also remains at a constant level, in the manner described in greater detail with reference to FIGS. 7 to 9 .
[0035] The device with individual displacement of rollers 16 - 19 also enables transverse rocking of the vehicle, in particular due to a difference of level of cables 11 , 12 , to be compensated. FIG. 5 represents such a rocking, in the absence of correction, the passengers having for example gathered in a group on the left side of vehicle 14 . Pendulum 24 detects this transverse rocking and transmits to trim corrector 23 a movement order of left-hand rollers 17 , 19 downwards to re-establish the vertical position of vehicle 15 , represented in FIG. 6 .
[0036] According to an important development of the invention, the device with independent rollers 16 - 19 ensures a straight trajectory 29 of vehicle 15 , at a constant level, in spite of a notable sag of the track constituted by cables 11 , 12 . In FIG. 2 , a detector (not shown), measuring for example the level of vehicle 15 with respect to the ground, controls downward displacement of the four rollers 16 - 19 over the descending path to reach the bottom position, on arrival at the bottom of the sag of cables 11 , 12 . On the following, ascending path, rollers 16 - 19 move up towards the top of the vehicle, and it can be seen that these displacements of rollers 16 - 19 thus ensure a straight trajectory of the vehicle on a track that undulates heightwise. Throughout its travel, the vehicle is naturally kept horizontal by differential action of the front rollers 16 , 17 with respect to the rear rollers 18 , 19 for longitudinal compensation, and of the left-hand rollers 17 , 19 with respect to the right-hand rollers 16 , 18 for transverse compensation.
[0037] Keeping a straight path 29 , in particular when passing over a shoe 26 of a pillar 13 , is illustrated in FIGS. 7 to 9 . The straight path is materialized by a laser beam 27 sent by an emitter 28 , securedly attached to the vehicle, to a fixed landmark 30 , for example located on a pillar at the required level. The displacements of rollers 16 - 19 are controlled by the trim detector with laser beam 27 , in the manner schematically represented by the direction of the arrows or jacks 22 , and it is needless to describe operation of the latter in detail.
[0038] In practice, the trim correctors are more elaborate than those described previously and they can for example comprise electronic systems for foreseeing and regulating displacement of the rollers, or, for a given installation, complete programming of the displacements.
[0039] According to another development of the invention, the trim correction system is completed by a device for damping brief and limited variations of the slopes of the track. The fixing system securing each roller 16 - 19 to its slide block 20 comprises a damper 31 , schematically represented in FIGS. 10-12 by a pair of springs 32 , 33 which urge the roller flexibly to a central position while enabling a limited vertical displacement. When passing over a short support 34 of cable 11 ( FIG. 11 ), the roller compresses damper 31 upwards to absorb the shock without transmitting it to the vehicle. After the passage ( FIG. 12 ), damper 31 returns to the normal position. Such dampers are well known.
[0040] In FIGS. 13 and 14 which illustrate an alternative embodiment, rollers 16 - 19 are located underneath floor 25 of vehicle 15 , at each of the four corners. A jack 22 for performing vertical displacement is associated with each roller 16 - 19 and all the jacks are connected to central unit 23 . Rollers 16 - 19 are represented in the available space under seats 40 situated at the ends of the car, but if the necessary displacement is greater than this space, rollers 16 - 19 can advantageously be placed outside the ground occupation space of the car. The traction system of the vehicle, represented here by a hauling cable 38 and coupling clamps 39 , can advantageously be situated underneath the floor of the vehicle, the same being the case for central unit 23 or for any other accessory. Doors 42 of the car, being able to be situated on both sides, are guided and controlled from a mechanism 41 also situated underneath the floor. A transverse detector 24 of rocking of the vehicle controls central unit 23 , which commands jacks 22 so as to prevent excessive rocking that may cause sideways toppling of the vehicle.
[0041] The advantage of an arrangement of the car above the cables is clearly apparent from FIGS. 15 and 16 which respectively represent a conventional installation with a hanger arm and very high pillars and an installation according to the invention.
[0042] Another alternative embodiment is illustrated by FIGS. 17 and 18 , which are similar views to FIGS. 3 and 4 . Jacks 22 connect rollers 16 - 19 to the essential parts of passenger compartment 15 , i.e. to floor 25 which supports the passengers. In this embodiment, the base of the passenger compartment is formed by a bottom and by a floor and the jacks are inserted between the bottom and the floor, in the manner represented in the figures. Operation is identical to that described above and this embodiment may be advantageous when the height variations remain small.
[0043] FIG. 19 is relative to a trajectory correction to reduce or compensate the vertical acceleration of the vehicle, in particular when passing over a pillar. The invention is applied to a vehicle of the type according to FIGS. 13 and 14 , which should advantageously be referred to for greater details, but it is clear that the described invention is applicable to the other vehicle systems described in the foregoing. Vehicle 15 without a hanger arm runs via four rollers 16 - 19 on a pair of carrying cables 11 , 12 that are spaced apart from one another. The rollers are located underneath vehicle 15 and a jack 22 , fitted between the roller and the floor of the vehicle, is associated with each roller. Jacks 22 of the vehicle, represented on the left in the figure, are controlled by a vertical acceleration detector 46 which controls central unit 23 .
[0044] Operation is easy to understand. When the cars are running on the substantially horizontal part of the track, jacks 22 are in an elongate position and they remain in this position so long as the vertical acceleration measured by detector 46 remains low. On approaching pillar 3 , the variation of the slope of cables 11 , 12 generates an ascending vertical acceleration, detected by detector 46 , which commands retraction of jacks 22 so as to remove the car towards the rollers.
[0045] The path taken by the car is not different from that of cables 11 , 12 and its flattened shape generates a reduced vertical acceleration. After the car has passed over the top of the shoe of pillar 3 , the descending vertical acceleration generates a reverse operation which brings the jacks back into the elongate position.
[0046] In the version of the installation according to FIG. 19 , the latter is advantageously improved by assigning to jacks 22 a function of maintaining the verticality of the car, described in the foregoing, in addition to the function of reducing the vertical acceleration. To this end, it suffices to provide sufficient travel of jacks 22 , which are active all along the line, and to add to detector 46 a trim corrector (not represented) controlling the verticality of the car.
[0047] Another manner of controlling jacks 22 according to the invention has been represented on the vehicle in the centre of FIG. 19 , in replacement of the vertical acceleration detector. A detector 47 arranged to collect data provided by an emitter 48 and concerning the cable, in particular the incline of the cable, when the vehicle passes, is fitted up-line from pillar 3 , for example on the ground. Detector 47 retransmits information, partially representative of the path of the cable when passing the pillar, to central unit 23 controlling jacks 22 . Depending on the installation, this information may be sufficient to control the jacks so as to reduce the vertical acceleration. The information can be specified by installing detectors 47 at several locations, and likewise by adding other sensors (not represented) to detector 47 , for example detecting the heightwise position of the vehicle, which depends on the weight of the vehicle. Central unit 23 can further receive other information, such as the speed of the cable, which determine the vertical acceleration.
[0048] In FIG. 20 , which is similar to FIG. 4 , each carrying cable is doubled up into two parallel and juxtaposed cables 11 , 11 ′ and 12 , 12 ′, and each roller is doubled up into two rollers 18 , 18 ′ and 19 , 19 ′, juxtaposed on the same spindle to run on the corresponding cable. It can be understood that in the event of malfunctioning of one of the assemblies, for example 11 - 18 , the juxtaposed assembly 11 ′- 18 ′ takes over and performs the carrying function.
[0049] FIG. 21 represents passage of a vehicle 15 from cable tracks 11 , 11 ′; 12 , 12 ′ to a rail track in a terminal station 49 , 49 ′; 50 , 50 ′, each cable being extended by a rail, and a gap, respectively 51 , 51 ′, always remains in the junction zone between the cable and the rail due to passage of cables 11 , 11 ′ diverted downwards, and 52 , 52 ′ for cables 12 , 12 ′. According to the invention, gaps 51 , 51 ′ are staggered longitudinally with respect to one another so that roller 11 ′ passes over gap 51 ′ before roller 11 passes over gap 51 . In identical manner, gaps 52 , 52 ′ are staggered.
[0050] It has been explained in the foregoing that the juxtaposition of the cables and that of the rollers enables one of the rollers to take over from the other in case of failure, and it can be understood that when roller 18 ′ passes gap 51 ′, it is roller 18 that takes over and performs supporting of vehicle 15 . Likewise, when roller 18 passes gap 51 , supporting is performed by roller 18 ′. Passage of the other gaps takes place in the same manner. Switching of the vehicle from the cables to the rails thus takes place without any jerking and switching can take place at high speed.
[0051] FIG. 22 is a similar view to FIG. 13 showing an alternative embodiment. The four rollers ( 16 - 19 ) are fixed to a chassis 62 and jacks 22 associated with each roller are fitted between chassis 62 and passenger compartment 15 .
[0052] FIGS. 23 and 24 represent a vehicle 15 , according to FIGS. 13 , 14 , detached from hauling cable 38 , running in a terminal station on rails 60 , the coupling clamps 39 of which are retracted so as not to encroach on the ground clearance 61 of the terminal.
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An overhead installation for transporting people in an urban environment includes two carrying cables, which sag in curved manner and are spaced apart from one another, on which the rollers of the vehicle without a hanger arm run. Jacks with vertical displacement, controlled by a central unit, are placed in the connection between the rollers and the vehicle so as to reduce transmission of undesirable movements, resulting from the sag of the cables, to the car of the vehicle.
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RELATED APPLICATION DATA
[0001] This application is a divisional patent application of U.S. Ser. No. 09/890,650 filed Mar. 22, 2002 which is a 371 of International Patent Application No. PCT/AU00/00070 filed on Feb. 7, 2000, which claims benefit of foreign priority under 35 USC §119 from Australian Patent Application No. PP8533 filed on Feb. 5, 1999 and Australian Patent Application No. PQ2013 filed on Aug. 4, 1999.
FIELD OF THE INVENTION
[0002] The present invention relates to T helper cell epitopes derived from Canine Distemper Virus (CDV). The present invention relates to compositions including at least one T helper cell epitope and optionally B cell epitopes and/or CTL epitopes.
BACKGROUND OF THE INVENTION
[0003] For any peptide to be able to induce an effective antibody response it must contain particular sequences of amino acids known as epitopes that are recognised by the immune system. In particular, for antibody responses, epitopes need to be recognised by specific immunoglobulin (Ig) receptors present on the surface of B lymphocytes. It is these cells which ultimately differentiate into plasma cells capable of producing antibody specific for that epitope. In addition to these B cell epitopes, the immunogen must also contain epitopes that are presented by antigen presenting cells (APC) to specific receptors present on helper T lymphocytes, the cells which are necessary to provide the signals required for the B cells to differentiate into antibody producing cells.
[0004] In the case of viral infections and in many cases of cancer, antibody is of limited benefit in recovery and the immune system responds with cytotoxic T cells (CTL) which are able to kill the virus-infected or cancer cell. Like helper T cells, CTL are first activated by interaction with APC bearing their specific peptide epitope presented on the surface, this time in association with MHC class I rather than class II molecules. Once activated the CTL can engage a target cell bearing the same peptide/class I complex and cause its lysis. It is also becoming apparent that helper T cells play a role in this process; before the APC is capable of activating the CTL it must first receive signals from the helper T cell to upregulate the expression of the necessary costimulatory molecules.
[0005] Helper T cell epitopes are bound by molecules present on the surface of APCs that are coded by class II genes of the major histocompatibility complex (MHC). The complex of the class II molecule and peptide epitope is then recognised by specific T-cell receptors (TCR) on the surface of T helper lymphocytes. In this way the T cell, presented with an antigenic epitope in the context of an MHC molecule, can be activated and provide the necessary signals for the B lymphocyte to differentiate. Traditionally the source of helper T cell epitopes for a peptide immunogen is a carrier protein to which peptides are covalently coupled but this coupling procedure can introduce other problems such as modification of the antigenic determinant during the coupling process and the induction of antibodies against the carrier at the expense of antibodies which are directed toward the peptide (Schutze, M. P., Leclerc, C. Jolivet, M. Audibert, F. Chedid, L. Carrier-induced epitopic suppression, a major issue for future synthetic vaccines. J. Immunol. 1985, 135, 2319-2322; DiJohn, D., Torrese, J. R. Murillo, J. Herrington, D. A. et al. Effect of priming with carrier on response to conjugate vaccine. The Lancet. 1989, 2, 1415-1416). Furthermore, the use of irrelevant proteins in the preparation introduces issues of quality control. The choice of appropriate carrier proteins is very important in designing peptide vaccines and their selection is limited by factors such as toxicity and feasibility of their large scale production. There are other limitations to this approach including the size of the peptide load that can be coupled and the dose of carrier that can be safely administered (Audibert, F. a C., L. 1984. Modem approaches to vaccines. Molecular and chemical basis of virus virulence and immunogenicity., Cold Spring Harbor Laboratory, New York.). Although carrier molecules allow the induction of a strong immune response they are also associated with undesirable effects such as suppression of the anti-peptide antibody response (Herzenberg, L. A. and Tokuhisa, T. 1980. Carrier-priming leads to hapten-specific suppression. Nature 285:664; Schutze, M. P., Leclerc, C., Jolivet, M., Audibert, F., and Chedid, L. 1985. Carrier-induced epitopic suppression, a major issue for future synthetic vaccines. J Immunol 135:2319; Etlinger, H. M., Felix, A. M., Gillessen, D., Heimer, E. P., Just, M., Pink, J. R., Sinigaglia, F., Sturchler, D., Takacs, B., Trzeciak, A., and et, a. 1988. Assessment in humans of a synthetic peptide-based vaccine against the sporozoite stage of the human malaria parasite, Plasmodium falciparum . J Immunol 140:626).
[0006] In general then, an immunogen must contain epitopes capable of being recognised by helper T cells in addition to the epitopes that will be recognised by surface Ig or by the receptors present on cytotoxic T cells. It should be realised that these types of epitopes may be very different. For B cell epitopes, conformation is important as the B cell receptor binds directly to the native immunogen. In contrast, epitopes recognised by T cells are not dependent on conformational integrity of the epitope and consist of short sequences of approximately nine amino acids for CTL and slightly longer sequences, with less restriction on length, for helper T cells. The only requirements for these epitopes are that they can be accommodated in the binding cleft of the class I or class II molecule respectively and that the complex is then able to engage the T-cell receptor. The class II molecule's binding site is open at both ends allowing a much greater variation in the length of the peptides bound (Brown, J. H., T. S. Jardetzky, J. C. Gorga, L. J. Stem, R. G. Urban, J. L. Strominger and D. C. Wiley. 1993. Three-dimensional structure of the human class II histocompatibility antigen HLA-DR1. Nature 364:33) with epitopes as short as 8 amino acid residues being reported (Fahrer, A. M., Geysen, H. M., White, D. O., Jackson, D. C. and Brown, L. E. Analysis of the requirements for class II-restricted T-cell recognition of a single determinant reveals considerable diversity in the T-cell response and degeneracy of peptide binding to I-Ed J. Immunol. 1995. 155: 2849-2857).
[0007] Canine distemper virus (CDV) belongs to the subgroup of morbillivirus of paramyxovirus family of negative-stranded RNA viruses. Other viruses which are members of this group are measles virus and rinderpest virus. Development of peptide based vaccines has aroused considerable interest in identification of B and T cell epitopes from sequences of proteins. The rationale for using T cell epitopes from proteins such as the F protein of CDV is that young dogs are inoculated against CDV in early life and will therefore possess helper T cells specific for helper T cell epitopes present on this protein. Subsequent exposure to a vaccine which contains one or more of the epitopes will therefore result in recruitment of existing helper T cells and consequently an enhanced immune response. Such helper T cell epitopes could, however, be administered to unprimed animals and still induce an immune response. The present inventors aimed to identify canine T cell epitopes from the sequence of CDV fusion protein so that these epitopes can then be used in the design of peptide based vaccines, in particular, for the canine and related species.
[0008] LHRH (Luteinising hormone releasing hormone) is a ten amino acids long peptide hormone whose sequence is conserved in mammals. It is secreted by the hypothalamus and controls the reproductive physiology of both males and females. The principle of development of LHRH-based immunocontraceptive vaccines is based on observations that antibodies to LHRH block the action of the hormone on pituitary secretion of luteinising hormone and follicle stimulating hormone, leading to gonadal atrophy and sterility in mammals.
[0009] Most LHRH vaccines that have been developed consist of LHRH chemically conjugated to protein carriers to provide T cell help for the generation of anti-LHRH antibodies. It has been shown that upon repeated inoculation of LHRH-protein carrier conjugates the anti-LHRH titre decreases due to the phenomenon known as “carrier induced epitope suppression”. One aim of the present inventors is to replace protein carriers in the vaccines with defined T helper epitopes (TH-epitopes) so as to eliminate “carrier induced epitope suppression”.
SUMMARY OF THE INVENTION
[0010] The present inventors have identified a number of 17 residue peptides each of which includes a T helper cell epitope. As will be readily appreciated the majority of these peptides are not minimal T helper cell epitopes. Typically class II molecules have been shown to be associated with peptides as short as 8 amino acids (Fahrer et al., 1995 ibid) but usually of 12-19 amino acids (Chicz, R. M., Urban, R. G., Gorga, J. C., Vignali, D. A. A., Lane, W. S. and Strominger, J. L. Specificity and promiscuity among naturally processed peptides bound to HLA-DR alleles. J Exp Med 1993, 178, 27-47; Chicz, R. M., Urban, R. G., Lane, W. S., Gorga, J. C., Stem, L. J., Vignali, D. A. A. and Strominger, J. L. Predominant naturally processed peptides bound to HLA-DR1 are derived from MHC-related molecules and are heterogeneous in size. Nature 1992, 358, 764-8), although, peptides up to 25 amino acids in length have been reported to bind to class II (reviewed in Rammensee, H.-G. Chemistry of peptide associated with class I and class II molecules. Curr Opin Immunol 1995, 7, 85-95.).
[0011] Thus peptide epitopes that range in length between 8 and 25 amino acid residues can bind to class II molecules. The shorter peptides are “core” epitopes that may have less activity than longer sequences but it is a trivial exercise to truncate longer sequences at the N- or the C-terminus to yield shorter sequences that have the same or better activity than the parent sequence.
[0012] Accordingly in a first aspect the present invention consists in a T helper cell epitope, the epitope being contained within a peptide sequence selected from the group consisting of SSKTQTHTQQDRPPQPS (SEQ ID NO: 1); QPSTELEETRTSRARHS (SEQ ID NO: 2); RHSTTSAQRSTHYDPRT (SEQ ID NO: 3); PRTSDRPVSYTMNRTRS (SEQ ID NO: 4); TRSRKQTSHRLKNIPVH (SEQ ID NO: 5); SHQYLVIKLIPNASLIE (SEQ ID NO: 6); IGTDNVHYKIMTRPSHQ (SEQ ID NO: 7); YKIMTRPSHQYLVIKLI (SEQ ID NO: 8); KLIPN A SLIENCTKAEL (SEQ ID NO: 9); AELGEYEKLLNSVLEPI (SEQ ID NO: 10); KLLNSVLEPINQALTLM (SEQ ID NO: 11); EPINQALTLMTKNVKPL (SEQ ID NO: 12); FAGVVLAGVALGVATAA (SEQ ID NO: 13); GVALGVATAAQITAGIA (SEQ ID NO: 14); TAAQITAGLALHQSNLN (SEQ ID NO: 15); GIALHQSNLNAQAIQSL (SEQ ID NO: 16); NLNAQAIQSLRTSLEQS (SEQ ID NO: 17); QSLRTSLEQSNK A IEEI (SEQ ID NO 18); EQSNK A IEEIREATQET (SEQ ID NO: 19); TELLSIFGPSLRDPISA (SEQ ID NO: 20); PRYI A TNGYLISNFDES (SEQ ID NO: 21); CIRGDTSSC A RTLVSGT (SEQ ID NO: 22); DESSCVFVSES A ICSQN (SEQ ID NO:23); TSTIINQSPDKLLTFI A (SEQ ID NO: 24), SPDKLLTFI A SDTCPLV (SEQ ID NO: 25) and SGRRQRRFAGVVLAGVA (SEQ ID NO: 26).
[0013] In a second aspect the present invention consists in a composition for use in raising an immune response in an animal, the composition comprising at least one T helper cell epitope, the at least one T helper cell epitope being contained within a peptide sequence selected from the group consisting of SSKTQTHTQQDRPPQPS (SEQ ID NO: 1); QPSTELEETRTSRARHS (SEQ ID NO: 2); RHSTTS A QRSTHYDPRT (SEQ ID NO: 3); PRTSDRPVSYTMNRTRS (SEQ ID NO: 4); TRSRKQTSHRLKNIPVH (SEQ ID NO: 5); SHQYLVIKLIPNASLIE (SEQ ID NO: 6); IGTDNVHIYKIMTRPSHQ (SEQ ID NO: 7); YKIMTRPSHQYLVIKLI (SEQ ID NO: 8); KLIPNASLIENCTKAEL (SEQ ID NO: 9); AELGEYEKLLNSVLEPI (SEQ ID NO: 10); KLLNSVLEPINQALTLM (SEQ ID NO: 11); EPINQALTLMTKNVKPL (SEQ ID NO: 12); FAGVVLAGVALGVATAA (SEQ ID NO: 13); GVALGVATAAQITAGIA (SEQ ID NO: 14); TAAQITAGIALHQSNLN (SEQ ID NO: 15); GIALHQSNLNAQAIQSL (SEQ ID NO: 16); NLNAQAIQSLRTSLEQS (SEQ ID NO: 17); QSLRTSLEQSNK A IEEI (SEQ ID NO: 18); EQSNK A IEEIREATQET (SEQ ID NO: 19); TELLSIFGPSLRDPISA (SEQ ID NO: 20); PRYI A TNGYLISNFDES (SEQ ID NO: 21); CIRGDTSSCARTLVSGT (SEQ ID NO: 22); DESSCVFVSESAICSQN (SEQ ID NO: 23); TSTIINQSPDKLLTFI A (SEQ ID NO: 24), SPDKLLTFI A SDTCPLV (SEQ ID NO: 25) and SGRRQRRF A GWLAGVA (SEQ ID NO: 26).
[0014] In a preferred embodiment of the present invention the composition comprises at least one peptide selected from the group consisting of SSKTQTHTQQDRPPQPS (SEQ ID NO: 1); QPSTELEETRTSRARHS (SEQ ID NO; 2); RHSTTSAQRSTHYDPRT (SEQ ID NO: 3); PRTSDRPVSYTMNRTRS (SEQ ID NO: 4); TRSRKQTSHRLKNIPVH (SEQ ID NO: 5); SHQYLVIKLIPNASLIE (SEQ ID NO: 6); IGTDNVHYKIMTTRPSHQ (SEQ ID NO: 7); YKIMTRPSHQYLVIKLI (SEQ ID NO: 8); KLIPNASLIENCTKAEL (SEQ ID NO: 9); AELGEYEKLLNSVLEPI (SEQ ID NO: 10); KLLNSVLEPINQALTLM (SEQ ID NO: 11); EPINQALTLMTKNVKPL (SEQ ID NO: 12); FAGVVLAGVALGVATAA (SEQ ID NO: 13); GVALGVATAAQITAGIA (SEQ ID NO: 14); TAAQITAGIALHQSNLN (SEQ ID NO: 15); GIALHQSNLNAQAIQSL (SEQ ID NO: 16); NLNAQAIQSLRTSLEQS (SEQ ID NO: 17); QSLRTSLEQSNKAIEEI (SEQ ID NO: 18); EQSNKAIEEIREATQET (SEQ ID NO: 19); TELLSIFGPSLRDPISA (SEQ ID NO: 20); PRYI A TNGYLISNFDES (SEQ ID NO: 21); CIRGDTSSC A RTLVSGT (SEQ ID NO: 22); DESSCVFVSESAICSQN (SEQ ID NO: 23); TSTIINQSPDKLLTFIA (SEQ ID NO: 24), SPDKLLTFIASDTCPLV (SEQ ID NO: 25) and SGRRQRRFAGWLAGVA (SEQ ID NO: 26).
[0015] It is further preferred that the composition further comprises at least one B cell epitope and/or at least one CTL epitope.
[0016] In yet another preferred embodiment the at least one B cell epitope and/or the at least one CTL epitope are linked to at least one of the T helper cell epitopes. It is also preferred that the composition comprises a plurality of epitope constructs in which each comprises at least one T helper cell epitope and at least one B cell epitope. Alternatively the composition may comprises a plurality of epitope constructs in which each comprises at least one T helper cell epitope and at least one CTL epitope.
[0017] It will be understood that the B cell epitope or CTL epitope may be any epitope. A currently preferred B cell epitope is an LHRH B cell epitope.
[0018] The composition of the present invention may comprises a plurality of T helper cell epitopes. These epitopes may be singular or be linked together to form a single polypeptide. It will be understood that where the epitopes are linked to together in a single polypeptide the epitopes may be contiguous or spaced apart by additional amino acids which are not themselves part of the T helper cell epitopes.
[0019] As discussed above in one embodiment the T helper cell epitopes and at least one B cell epitope and/or at least one CTL epitope in which the epitopes are linked. This may be done by simple covalent linkage of the peptides. In another embodiment the epitopes are polymerised, most preferably such as described in PCT/AU98/00076, the disclosure of which is incorporated herein by reference.
[0020] In yet another preferred embodiment the composition further comprises a pharmaceutically acceptable excipient, preferably an adjuvant.
[0021] In a further aspect the present invention consists in a method of inducing an immune response in an animal, the method comprising administering to the animal the composition of the second aspect of the present invention.
[0022] Pharmaceutically acceptable carriers or diluents include those used in compositions suitable for oral, rectal, nasal, topical (including buccal and sublingual), vaginal, parenteral (including subcutaneous, intramuscular, intravenous, intradermal, intrathecal and epidural) administration. They are non-toxic to recipients at the dosages and concentrations employed. Representative examples of pharmaceutically acceptable carriers or diluents include, but are not limited to water, isotonic solutions which are preferably buffered at a physiological pH (such as phosphate-buffered saline or Tris-buffered saline) and can also contain one or more of, mannitol, lactose, trehalose, dextrose, glycerol, ethanol or polypeptides (such as human serum albumin). The compositions may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy.
[0023] As mentioned it is preferred that the composition includes an adjuvant. As will be understood an “adjuvant” means a composition comprised of one or more substances that enhances the immunogenicity and efficacy of a vaccine composition. Non-limiting examples of suitable adjuvants include squalane and squalene (or other oils of animal origin); block copolymers; detergents such as Tween®-80; Quil® A, mineral oils such as Drakeol or Marcol, vegetable oils such as peanut oil; Corynebacterium -derived adjuvants such as Corynebacterium parvum; Propionibacterium -derived adjuvants such as Propionibacterium acne; Mycobacterium bovis (Bacille Calmette and Guerin or BCG); interleukins such as interleukin 2 and interleukin 12; monokines such as interleukin 1; tumour necrosis factor, interferons such as gamma interferon; combinations such as saponin-aluminium hydroxide or Quil-A aluminium hydroxide; liposomes; ISCOM adjuvant; mycobacterial cell wall extract; synthetic glycopeptides such as muramyl dipeptides or other derivatives; Avridine; Lipid A derivatives; dextran sulfate; DEAE-Dextran or with aluminium phosphate; carboxypolymethylene such as Carbopol' EMA; acrylic copolymer emulsions such as Neocryl A640 (e.g. U.S. Pat. No. 5,047,238); vaccinia or animal poxvirus proteins; sub-viral particle adjuvants such as cholera toxin, or mixtures thereof.
[0024] As will be recognised by those skilled in the art modifications may be made to the peptides of the present invention without complete abrogation of biological activity. These modifications include additions, deletions and substitutions, in particular conservative substitutions. It is intended that peptides including such modifications which do not result in complete loss of activity as T helper cell epitopes are within the scope of the present invention.
[0025] Whilst the concept of substitution is well known in the field the types of substitutions envisaged are set out below.
Preferred Original Residue Exemplary Substitutions Substitutions Ala (A) val; leu; ile Val Arg (R) lys; gln, asn Lys Asn (N) gln; his; lys; arg Gln Asp (D) glu Glu Cys (C) ser Ser Gln (Q) asn asn Glu (E) asp asp Gly (G) pro pro His (H) asn; gln; lys; arg arg Ile (I) leu; val; met; ala; phe, norleucine leu Leu (L) norleucine, ile; val; met; ala; phe ile Lys (K) arg; gln; asn arg Met (M) leu; phe; ile; leu Phe (F) leu; val; ile; ala leu Pro (P) Gly gly Ser (S) Thr thr Thr (T) Ser ser Trp (W) Tyr tyr Tyr (Y) trp; phe; thr; ser phe Val (V) ile; leu; met; phe ala; norleucine leu
[0026] Another type of modification of the peptides envisaged include, but are not limited to, modifications to side chains, incorporation of unnatural amino acids and/or their derivatives during peptide synthesis and the use of crosslinkers and other methods which impose conformational constraints on the peptides.
[0027] Examples of side chain modifications contemplated by the present invention include, but are not limited to, modifications of amino groups such as by reductive alkylation by reaction with an aldehyde followed by reduction with NaBH 4 ; amidation with methylacetimidate; acylation with acetic anhydride; carbamoylation of amino groups with cyanate; trinitrobenzylation of amino groups with 2,4,6trinitrobenzene sulphonic acid (TNBS); acylation of amino groups with succinic anhydride and tetrahydrophthalic anhydride; and pyridoxylation of lysine with pyridoxal-5′-phosphate followed by reduction with NaBH 4 .
[0028] The guanidine group of arginine residues may be modified by the formation of heterocyclic condensation products with reagents such as 2,3-butanedione, phenylglyoxal and glyoxal.
[0029] The carboxyl group may be modified by carbodiimide activation via O-acylisourea formation followed by subsequent derivitisation, for example, to a corresponding amide.
[0030] Tryptophan residues may be modified by, for example, oxidation with N-bromosuccinimide or alkylation of the indole ring with 2-hydroxy-5-nitrobenzyl bromide or sulphenyl halides. Tyrosine residues on the other hand, may be altered by nitration with tetranitromethane to form 3-nitrotyrosine derivative.
[0031] Modification of the imidazole ring of a histidine residue may be accomplished by alkylation with iodoacetic acid derivatives or N-carbethoxylation with diethylpyrocarbonate.
[0032] Examples of incorporating unnatural amino acids and derivatives during peptide synthesis include, but are not limited to, use of norleucine, 4-amino butyric acid, 4-amino-3-hydroxy-5-phenylpentanoic acid, 6-aminohexanoic acid, t-butylglycine, norvaline, phenylglycine, ornithine, sarcosine, 4-amino-3-hydroxy-6-methylheptanoic acid; 2-thienyl alanine and/or D-isomers of amino acids.
[0033] The peptides of the present invention may be derived from CDV. Alternatively, the peptide or combination of peptide epitopes may be produced by recombinant DNA technology. It is, however, preferred that the peptides are produced synthetically using methods well known in the field. For example, the peptides may be synthesised using solution synthesis or solid phase synthesis as described, for example, in Chapter 9 entitled “Peptide Synthesis” by Atherton and Sheppard which is included in a publication entitled “Synthetic Vaccines” edited by Nicholson and published by Blackwell Scientific Publications. Preferably a solid phase support is utilised which may be polystyrene gel beads wherein the polystyrene may be cross-linked with a small proportion of divinylbenzene (e.g. 1%) which is further swollen by lipophilic solvents such as dichloromethane or more polar solvents such as dimethylformamide (DMF). The polystyrene may be functionalised with chloromethyl or aminomethyl groups. Alternatively, cross-linked and functionalised polydimethyl-acrylamide gel is used which may be highly solvated and swollen by DMF and other dipolar aprotic solvents. Other supports can be utilised based on polyethylene glycol which is usually grafted or otherwise attached to the surface of inert polystyrene beads. In a preferred form, use may be made of commercial solid supports or resins which are selected from PAL-PEG-PS, PAC-PEG-PS, KA, KR or TGR.
[0034] In solid state synthesis, use is made of reversible blocking groups which have the dual function of masking unwanted reactivity in the α-amino, carboxy or side chain functional groups and of destroying the dipolar character of amino acids and peptides which render them inactive. Such functional groups can be selected from t-butyl esters of the structure RCO—OCMe 3 -CO. Use may also be made of the corresponding benzyl esters having the structure RCO—OCH 2 —C 6 H 5 and urethanes having the structure C 6 H 5 CH 2 OCO—NHR which are known as the benzyloxycarbonyl or Z-derivatives and any Me 3 -COCO—NHR, which are known as t-butoxyl carbonyl, or Boc derivatives. Use may also be made of derivatives of fluorenyl methanol and especially the fluorenyl-methoxy carbonyl or Fmoc group. Each of these types of protecting group is capable of independent cleavage in the presence of one other so that frequent use is made, for example, of BOC-benzyl and Fmoc-tertiary butyl protection strategies.
[0035] Reference also should be made to a condensing agent to link the amino and carboxy groups of protected amino acids or peptides. This may be done by activating the carboxy group so that it reacts spontaneously with a free primary or secondary amine. Activated esters such as those derived from p-nitrophenol and pentafluorophenol may be used for this purpose. Their reactivity may be increased by addition of catalysts such as 1-hydroxybenzotriazole. Esters of triazine DHBT (as discussed on page 215-216 of the abovementioned Nicholson reference) also may be used. Other acylating species are formed in situ by treatment of the carboxylic acid (i.e. the N-alpha-protected amino acid or peptide) with a condensing reagent and are reacted immediately with the amino component (the carboxy or C-protected amino acid or peptide). Dicyclohexylcarbodiimide, the BOP reagent (referred to on page 216 of the Nicholson reference), O'Benzotriazole-N,N, N′N′-tetra methyl-uronium hexafluorophosphate (HBTU) and its analogous tetrafluoroborate are frequently used condensing agents.
[0036] The attachment of the first amino acid to the solid phase support may be carried out using BOC-amino acids in any suitable manner. In one method BOC amino acids are attached to chloromethyl resin by warming the triethyl ammonium salts with the resin. Fmoc-amino acids may be coupled to the p-alkoxybenzyl alcohol resin in similar manner. Alternatively, use may be made of various linkage agents or “handles” to join the first amino acid to the resin. In this regard, p-hydroxymethyl phenylacetic acid linked to aminomethyl polystyrene may be used for this purpose.
[0037] Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
DETAILED DESCRIPTION OF THE INVENTION
[0038] In order that the nature of the present invention may be more readily understood preferred forms there of will now be described with reference to the following non-limiting examples.
FIGURE LEGENDS
[0039] FIG. 1 . Amino acid sequence of the fusion protein of CDV (SEQ ID NO: 27)
[0040] FIG. 2 a . Stimulation indices to Th-epitope P25 and its truncated versions in Dog #70 immunised with P25-LHRH (X-axis concentration of peptides nmoles/well).
[0041] FIG. 2 b Stimulation indices to Th-epitope P25 and its truncated versions in Dog #73 immunised with P25-LHRH α-axis concentration of peptides nmoles/well).
[0042] FIG. 2 c Stimulation indices to Th-epitope P25 and its truncated versions in Dog #127 immunised with P25-LHRH (X-axis concentration of peptides nmoles/well)
[0043] FIG. 2 d Stimulation indices to Th-epitope P25 and its truncated versions in Dog #993 immunised with P25-LHRH (X-axis concentration of peptides nmoles/well).
[0044] FIG. 3 a Stimulation indices to Th-epitope P27 and its truncated 15-mer in Dog #105 immunised with P27-LHRH. (X-axis concentration of peptides moles/well).
[0045] FIG. 3 b . Stimulation indices to Th-epitope P27 and its truncated 15-mer in) Dog #94 immunised with P27-LHRH. (X-axis concentration of peptides nmoles/well).
[0046] FIG. 3 c . Stimulation indices to Th-epitope P27 and its truncated 15-mer in Dog #20 immunised with P27-LHRH. (X-axis concentration of peptides mmoles/well).
[0047] FIG. 3 d . Stimulation indices to Th-cpitope P27 and its truncated 15-mer in Dog #101 immunised with P27-LHRH. (X-axis concentration of peptides nmoles/well).
[0048] FIG. 4 a . Stimulation indices to Th-epitope P35 and its truncated versions in Dog #19 immunised with P35-LHRH (X-axis concentration of peptides nmoles/well).
[0049] FIG. 4 b . Stimulation indices to Th-epitope P35 and its truncated versions in Dog #100 immunised with P35-LHRH (X-axis concentration of peptides nmoles/well).
[0050] FIG. 4 c . Stimulation indices to Th-epitope P35 and its truncated versions in Dog #96 immunised with P35-LHRH (X-axis concentration of peptides mmoles/well).
[0051] FIG. 4 d . Stimulation indices to Th-epitope P35 and its truncated versions in Dog #102 immunised with P35-LHRH (X-axis concentration of peptides nmoles/well).
EXAMPLE 1
[0000] Identification of T Helper Cell Epitopes
[0000] Methods and Results:
[0052] Towards identification of canine T cell epitopes 94, 17 residue overlapping peptides were designed encompassing the entire sequence of fusion protein of canine distemper virus (CDV). The 17mer peptides were numbered sequentially for identification starting from the N-terminus. The sequence of the fusion protein of CDV as determined by Barrett et al 1987 (Virus Res. 8, 373-386) is shown in FIG. 1 . The peptides were used in T-cell proliferation assays using peripheral blood lymphocytes (PBMC) from dogs immunised with Canvac™ 3 in 1 vaccine (CSL Limited) which contains live CDV.
[0053] Initially, four dogs were used and they were boosted with the Canvac™ 3 in 1 vaccine twice with four to six weeks between each vaccination. The dogs were bled after each booster vaccination and the PBMCs were tested against the peptides. No significant proliferation to peptides was observed.
[0054] Since CDV has been reported to be lymphotropic and the vaccine consists of live CDV, there was the possibility that it may be sequestered in lymphoid organs preventing significant numbers of precursor T cells entering the peripheral system. To increase the frequency of peripheral blood anti-CDV T cells dogs were boosted with heat killed CDV (obtained as a pellet from virus culture medium, CSL Limited). Two weeks later, the dogs were bled and the PBMCs tested for proliferation against the peptides. Again there was no proliferation to the peptide antigens.
[0055] An alternate strategy was used to increase the precursor frequency of specific T cells recognising the CDV peptides. Fresh PBMCs obtained from these hyperimmunised dogs were subjected to stimulation in vitro with pools of all 94 peptides for 30 minutes at 37° C. The cells were then washed to remove any excess peptides and cultured for 7 days. This population of T cells was then tested with autologous APCs with every single peptide as the antigen. Table 1 shows the peptides to which significant (stimulation index>2) levels of proliferation were observed.
[0056] To confirm this observation, the same four dogs were bled again, five weeks after receiving the dose of killed virus. The PBMCs were stimulated in vitro with pools of either all 94 peptides or peptides 21-40 (because most of the activity was in this region) and after 7 days of culture the stimulated T cells were tested against individual peptides. Significant stimulatory indices were obtained with all peptides, confirming the above results. Four more dogs which received only one dose of 3 in 1 vaccine were tested using the in vitro stimulation method and all four dogs responded to the majority of peptides shown in Table 2.
[0057] The above peptides were also tested on cells from additional dogs, with results shown in Table 3. Peptides P64, P74 and P75 were also shown to react strongly with peripheral blood mononuclear cells from dogs of various breeds immunised with CDV (Table 4), and are therefore identified as strong T-helper epitopes.
TABLE 1 Identification of canine T cell epitopes from the sequence of fusion protein of CDV. Beagle Beagle Beagle Beagle Foxhound Foxhound Foxhound Foxhound Peptides (Dog#18) (Dog#19) (Dog#20) (Dog#21) p2 2* <2 8 3.9 p4 4.9 <2 3.3 4.6 p6 2.5 <2 4 5.1 p10 2.3 <2 3.2 9.1 p24 5.8 9.9 2.8 29 p25 3.2 11.9 4.5 17 p27 3.3 34 6.7 14.8 p29 3.5 42 4.4 <2 p35 3.1 57 3.3 22 p36 6.7 3.7 3.3 16 p37 6.9 10.9 8.2 26 p38 2.8 6.7 3.6 4.2 p47 3.3 85.7 2.9 1.9 p62 <2 51 5.6 4.2 p68 6.6 <2 <2 11.7 *Stimulatory index
[0058]
TABLE 2
Identification of canine T cell epitopes from the sequence of
fusion protein of CDV.
Beagle
Beagle
Beagle
Foxhound
Foxhound
Foxhound
Beagle Foxhound (Dog
Peptides
(Dog #70)
(Dog #71)
(Dog #72)
#73)
p8
2.2
p22
2.6
p24
3.2
2.2
p25
1.5
2.9
2
12
p27
2.7
3.5
4.8
p28
2
p29
2
6
p33
1.6
p35
1.7
6.8
p37
1.7
p62
3
[0059]
TABLE 3
Identification of canine T cell epitopes from the sequence of
fusion protein of CDV.
Peptides
Kelpie Foxhound (Dog#125)
Kelpie Foxhound (Dog#126)
p23
3.2
p27
4.5
8.5
p28
1.9
p29
3.6
p33
6
p34
2.1
p35
3.8
10
p36
3
p37
2.5
p38
2.2
p39
2.9
p47
2.7
p62
2.4
p68
2.9
[0060]
TABLE 4
Identification of canine T cell epitopes from the sequence of
fusion protein of CDV.
Poodle
Beagle
Beagle
Beagle
Beagle
Peptides
Shitzu
Foxhound#18
Foxhound#19
Foxhound#20
Foxhound#21
P64
50.0
2.5
2.5
P74
4.0
1.7
6.0
P75
10
2.5
7.2
[0061] Once again the same peptides and one additional peptide P32 were tested on cells from additional dogs. These peptides were also shown to react strongly with peripheral blood mononuclear cells from dogs of various breeds immunised with CDV (Table 5), and are therefore identified as strong T-helper epitopes.
[0062] In conclusion, 26 peptides were identified as canine T helper cell epitopes in the fusion protein of CDV. The sequences of each of these peptides are set out in Table 6.
[0063] These T helper cell epitopes will have usefulness as components of animal, in particular, canine vaccines, either simply as synthetic peptide based vaccines and as additions to vaccines containing more complex antigens.
TABLE 5 Identification of canine T cell epitopes from the sequence of fusion protein of CDV. Poodle Grey Fox Terrier Kelpie Border Peptides Shitzu hound Terrier Cross Pointer Collie P2 140 <2 <2 <2 2.6 2 P4 44 2 <2 2 3.5 2 P6 38 <2 <2 <2 <2 2 P8 100 2 <2 <2 2.8 2 P10 50 2 2.2 2.1 2.4 3 P25 <2 <2 2.6 <2 2.6 <2 P29 2 <2 <2 2 <2 <2 P32 <2 2 <2 <2 <2 <2 P33 <2 <2 <2 <2 2 2 P35 <2 <2 2.2 <2 2 2 P37 <2 <2 <2 2 2 <2 P62 24 <2 <2 <2 <2 <2 P64 50 <2 <2 <2 <2 <2 P68 5 <2 <2 <2 <2 <2 P74 4 <2 <2 <2 <2 <2 P75 10 <2 <2 <2 <2 <2
[0064]
TABLE 6
Sequences of the peptides:
P2
SSKTQTHTQQDRPPQPS (SEQ ID NO: 1)
P4
QPSTELEETRTSRARHS (SEQ ID NO: 2)
P6
RHSTTSAQRSTHYDPRT (SEQ ID NO: 3)
P8
PRTSDRPVSYTMNRTRS (SEQ ID NO: 4)
P10
TRSRKQTSHRLKNIPVH (SEQ ID NO: 5)
P24
SHQYLVIKLIPNASLIE (SEQ ID NO: 6)
P22
IGTDNVHYKIMTRPSHQ (SEQ ID NO: 7)
P23
YKIMTRPSHQYLVLKLI (SEQ ID NO: 8)
P25
KLIPNASLIENCTKAEL (SEQ ID NO: 9)
P27
AELGEYEKLLNSVLEPI (SEQ ID NO: 10)
P28
KLLNSVLEPINQALTLM (SEQ ID NO: 11)
P29
EPINQALTLMTKNVKPL (SEQ ID NO: 12)
P32
SGRRQRRFAGVVLAGVA (SEQ ID NO: 26)
P33
FAGVVLAGVALGVATAA (SEQ ID NO: 13)
P34
GVALGVATAAQITAGIA (SEQ ID NO: 14)
P35
TAAQITAGIALHQSNLN (SEQ ID NO: 15)
P36
GIALHQSNLNAQAIQSL (SEQ ID NO: 16)
P37
NLNAQAIQSLRTSLEQS (SEQ ID NO: 17)
P38
QSLRTSLEQSNKAIEEI (SEQ ID NO: 18)
P39
EQSNKAIEEIREATQET (SEQ ID NO: 19)
P47
TELLSIFGPSLRDPISA (SEQ ID NO: 20)
P62
PRYIATNGYLISNFDES (SEQ ID NO: 21)
P68
CIRGDTSSCARTLVSGT (SEQ ID NO: 22)
P64
DESSCVPVSESAICSQN (SEQ ID NO: 23)
P74
TSTIINQSPDKLLTFIA (SEQ ID NO: 24)
P75
SPDKLLTFIASDTCPLV (SEQ ID NO: 25)
[0065] Selected sequences of the identified T-cell epitopes were tested for their ability to induce an antibody response to a linked B-cell epitope. Trials were conducted in dogs for assessment of antibody responses. The Tell epitopes were linked to the B cell epitope LHRH (leuteinising hormone releasing hormone), with the T-cell epitope at the N-terminus and LHRH positioned at the carboxy terminus.
[0066] Peptides were synthesised using standard chemistry with Fmoc protection. All peptides were purified to at least 80% purity and the product checked by mass spectroscopy.
[0067] The peptides were produced as contiguous T-cell-B cell determinants. The LHRH sequence of Pyro Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly (SEQ ID NO: 28), or variations of it, was linked to the carboxyl terminus of each respective CDV T-helper epitope.
[0068] In-vivo evaluation of some of the T-helper epitopes was conducted in two trials, by vaccination of dogs with T-helper—LHRH sequences.
EXAMPLE 2
Trial K9-5
[0069] A total of 14 dogs of mixed sex were used in this trial. All had been previously vaccinated with a live CDV vaccine and had also been vaccinated against LHRH.
[0000] Vaccine Formulation.
[0070] Test peptides P25, P27, P35 from CDV were synthesised with LHRH at the C terminus of each T-helper epitope. The LHRH sequence used was the full 10 amino acids of the native LHRH. Each of the vaccine constructs, together with a control peptide comprising a mouse influenza T-cell epitope linked to a repeat malarial B-cell epitope (sequence shown in table below) were purified to −80-90% purity. All peptides were dissolved in 4M urea before dilution with sterile saline to an appropriate volume to give 40 nmoles per 1 mL dose. Iscomatrix™ was added to a final concentration of 150 ug/1 mL dose as adjuvant together with thiomersal preservative (0.01%).
[0071] ISCOM™ or Immunostimulating Complex (Barr, Sjolander and Cox, 1998, Advanced Drug Delivery Systems 32: 247-271) are a well characterised class of adjuvant comprised of a complex of phospholipid, cholesterol and saponin, usually with a protein incorporated into the complex. Where the complex is formed in the absence of protein antigen, then this complex is termed Iscomatrix™. The saponin used in the preparation of this adjuvant was Quil A.
[0000] Vaccination, Blood Samples and Assays.
[0072] All dogs were vaccinated with a 1 mL dose, delivered in the scruff of the neck Vaccinations were given at 0 and 4 weeks and venous blood samples were obtained at intervals during the trial.
[0073] Effective T-cell help was determined by measuring the antibody response to LHRH by ELISA. Biological effectiveness of the peptide based vaccine was determined by measuring the levels of progesterone in female dogs and testosterone in male dogs. Table 7.
TABLE 7 Trial Groups Peptide Dog Nos. Control-ALNNRFQIKGVELKS-(NANP)3 104, 998 (SEQ ID NO: 30) P25-LHRH 1-10 70, 73, 127, 993 P27-LHRH 1-10 20, 94, 101, 105 P35-LHRH 1-10 19, 96, 100, 102
Results
[0074] Pre-existing low antibody levels to LHRH were present in all dogs due to immunisation previously with a different vaccine. The control group of dogs exhibited a slow decrease in antibody levels.
[0075] Dogs immunised with P25-LHRH, P27-LHRH and P35-LHRH all showed strong antibody responses to the B-cell epitope (LHRH). This response persisted to 6 weeks post boost vaccination (see Table 8).
[0076] The biological potency of the vaccine was demonstrated by a significant reduction in progesterone or testosterone levels (see Tables 9 and 10).
TABLE 8 Anti LHRH Titres Anti LHRH Titres Dog 2 wks 6 wks Peptide No Prebleeds post boost post boost Control 104 1258 1975 1936 998 2559 1982 1947 Average 1794 1978 1941 Range 1258-2559 1975-1982 1936-1947 P25-LHRH 70 856 24245 16697 (1-10) 73 42665 16922 127 1361 21485 19662 993 577 24879 15119 Average 886 23120 17242 Range 0-1361 21485-42665 15119-19662 p27-LHRH 20 747 29653 8423 (1-10) 94 41247 22759 101 4256 52724 17353 105 944 12600 8366 Average 2004 25774 12049 Range 747-4256 12600-52724 8366-22759 p35-LHRH 19 665 18033 6228 (1-10) 96 1621 26583 5744 100 580 17255 4829 102 180 11740 2963 Average 323 14233 3783 Range 180-1621 11740-26583 2963-6228
[0077]
TABLE 9
Progesterone results (nmol/L)
Dog
4 wks
2 wks
6 wks
Peptide
No.
post primary
post boost
post boost
Control
998
5.17
4.28
<0
p25-LHRH
127
3.04
4.83
<0
(1-10)
993
1.7
0.87
<0
p27-LHRH
101
0.42
0.14
<0
(1-10)
p35-LHRH
96
31.76
2.15
<0
(1-10)
100
<0
<0
<0
[0078]
TABLE 10
Testosterone results (nmoI/L
Dog
4 wks
2 wks
6 wks
Peptide
No.
post primary
post boost
post boost
Control
104
9.69
2.51
3.31
p25-LHRH
70
<0
<0
<0
(1-10)
73
5.38
<0
<0
p27-LHRH
20
1.04
<0
<0
(1-10)
94
3.33
<0
<0
105
>47.7
<0
<0
p35-LHRH
19
4.3
2.77
4.55
(1-10)
102
6.72
<0
<0
[0079] The effectiveness of selected T-cell epitopes from the F-protein of CDV in providing T-cell help to elicit antibody responses in dogs proves that the identified sequences are functional. These results also validate the scientific approach and usefulness of the in vitro screening method for identifying T-helper epitope sequences with in vivo activity.
EXAMPLE 3
Trial K9-8
[0080] A total of 35 dogs mixed sex were used in this trial. All had been previously vaccinated with a live CDV vaccine but had not been vaccinated against LHRH.
[0000] Vaccine Formulation:
[0081] The T-Helper epitopes were linked to a truncated form of LHRH, containing amino acids 2 to 10 of the native 10 amino acid sequence, as shown below:
(SEQ ID NO: 29) 2-10 LHRH His-Trp-Ser-Iyr-Gly-Leu-Arg-Pro-Gly.
[0082] All vaccines were formulated as for Example 2, ie each 1 mL dose of vaccine contained 40mmoles of peptide, 150 μg Iscomatrix™, and thiomersal as preservative.
[0083] Where dogs were vaccinated with a pool of peptides, the concentration of each peptide was adjusted to give equal concentrations and a total amount of 40 nmoles of LHRH epitope per 1 mL dose.
[0000] Vaccination, Blood Samples and Assays.
[0084] All dogs were vaccinated with a 1 mL dose, delivered in the scruff of the neck. Vaccinations were given at 0 and 4 weeks and venous blood samples were obtained at intervals during the trial.
[0085] Effective T-cell help was determined by measuring the antibody response to LHRH by ELISA. Biological effectiveness of the peptide based vaccine was determined by measuring the levels of progesterone in female dogs and testosterone in male dogs.
TABLE 11 Trial Groups Peptide Group Dog Nos. P25-LHRH 2-10 211, 195, 197, 181 P27-LHRH 2-10 203, 191, 186, 201 P35-LHRH 2-10 217, 198, 187, 196 Pool: P25-LHRH 2-10, 212, 193, 178, 216, Y3 P27-LHRH 2-10, P35-LHRH 2-10 P2-LHRH 2-10 194, 199, 179, 220 P8-LHRH 2-10 Y4, Y6, 160, 200 P62-LHRH 2-10 219, 185, 221, 177 P75-LHRH 2-10 189, 222, 202, 176 Unvaccinated controls 190, 159
Results
[0086] Strong antibody responses to LHRH were demonstrated in dogs immunised with the T-cell-LHRH constructs with the T-cell epitopes P25, P27, P35, P62, P75, and the pool of T-cell-LHRH peptides comprising a combination of T-cell epitopes P25, P27 and P35 (see Table 12).
[0087] Low to undetectable antibody responses were seen in dogs immunised with P2 and P8-LHRH peptides (see Table 12). This was concluded to indicate that these T-cell peptides were not well recognised by Beagle-Foxhound dogs, which is consistent with their identification using PBMCs' from other dog breeds. The initial screening in Beagle foxhound dogs indicated that this breed of dog does not respond to these 2 T-cell epitopes.
[0088] As is well understood by those skilled in the art of peptide vaccines the response to individual peptides is genetically determined. The class II Major Histocompatability Complex (MHC II) is polymorphic. Class II molecules at the cell surface function to bind peptides for presentation to T-cells, which is required as part of the activation process for T-cells, including helper T-cells. The allelic forms of MHC class II bind discrete sets of peptide antigens, and thus the response to those antigens is genetically determined. Thus the results are interpreted to indicate that the Beagle—Foxhound breed of dog does not possess the appropriate MHC-II alleles to respond to P2 and P8, but that other breeds of dog do, eg. the Poodle Shitzu breed that were used to identify these peptides.
[0089] Control dogs showed no change in antibody levels to LHRH during the trial period and hormone levels were within normal ranges for the age and sex of the dogs (see Table 12).
TABLE 12 Anti-LHRH Titres Anti LHRH Titres 4 wks after 2 wks post 4 wks post Peptide Group Dog No primary boost boost Control 1 159 0 0 0 1 190 0 0 0 GMT Pool 2 Y3 1860 55659 95038 2 178 17900 416036 486793 2 193 8770 211369 189143 2 212 3766 121411 135293 2 216 8378 294769 642293 GMT 6207 177292 237798 P25-LHRH 3 181 1893 152264 131643 3 195 31197 205906 455193 3 197 14423 337698 240543 3 211 20607 142798 131643 GMT 11510 193037 214229 P27-LHRH 4 186 0 11206 17263 4 191 0 59154 125493 4 201 0 17041 34103 4 203 0 1000 857 GMT 0 18523 26698 P35-LHRH 5 187 2009 141775 55797 5 196 4868 237208 158040 5 198 1539 154375 68307 5 217 0 121050 40822 GMT 2469 103085 58002 P2-LHRH 6 179 0 0 0 6 194 0 0 0 6 199 0 0 0 6 220 0 0 0 GMT P8-LHRH 7 Y4 0 0 0 7 Y6 0 0 0 7 160 0 1200 ND 7 200 0 8000 2227 GMT P62-LHRH 8 177 1242 3821 2985 8 185 0 146581 67461 8 219 0 29353 28282 8 221 2697 231473 156549 GMT 1830 44167 30728 P75-LHRH 9 176 0 12177 5559 9 189 0 15795 17155 9 202 0 2121 2216 9 222 0 9787 7879 GMT 11201 8746
EXAMPLE 4
[0000] In Vitro T Cell Proliferation Assays to Demonstrate Recognition of Th-Epitope Incorporated in the Peptide Vaccines
[0090] To demonstrate recognition of the Th-epitope within the peptide immunogen PBMCs obtained from dogs immunised with peptide vaccines (dogs from Example 2) were tested against the respective Th-epitopes. The assay was carried out without the enrichment of PBMCs. PBMCs obtained from Ficoll gradient purification were directly tested against the respective Th epitope and its truncated versions. The study demonstrated that all the dogs immunised with peptide vaccines responded to the Th-epitope incorporated confirming that T cell activity resides in the respective sequences ( FIGS. 24 ). Truncated versions of the respective Th-epitopes were also tested to more closely define the T-cell activity within the sequences. It was observed that for P25 the full sequence of 17 residues was better than the shorter peptides of 15 and 12 residues, each truncated from the N-terminus of the sequence ( FIG. 2 ). This implies that the T-cell activity is towards the N-terminus or middle of the 17-residue peptide.
[0091] A similar observation was made with P27, the 17 residue long peptide was a better simulator than the 15-mer truncated from the N-terminus ( FIG. 3 ). This observation again suggested that the T-cell activity may reside towards the middle or the N-terminus of the full length peptide.
[0092] In the case of P35 and its shorter versions, except for one dog (#102), the other three dogs responded as well to the 12 residue peptide as to the full length 17 residue one ( FIG. 4 ). In dog # 102 the 15 residue peptide was more stimulatory than the full length peptide. From this it can be deduced that that the first two residues in the sequence of P35 may not be essential and that the activity is towards the middle or C-terminus of the peptide.
EXAMPLE 5
[0000] Trial in BALB/c Mice
[0093] The canine vaccines with CDV-F derived Th-epitopes and LHRH used in Example 3 were also used to immunise BALB/c mice to investigate if the Th-epitopes would be functional in a different animal species.
[0000] Vaccine Formulation
[0094] All vaccines were formulated as for Example 3 except that they were diluted further so that 100 μL doses contained 2.7 nmoles of peptide and 10 μg of Iscomatrix™ and thiomersol as preservative.
[0000] Vaccination, Blood Samples and Assays.
[0095] Mice were vaccinated with 100 μl of the vaccine at the base of tail. Vaccinations were given at 0 and 4 weeks and animals bled at intervals after each vaccination from the retro-orbital plexus. Effective T-cell help was determined by measuring the antibody response to LHRH by ELISA.
[0000] Results
[0096] Mice immunised with P25-LHRH and pool of peptides comprising of P25-LHRH, P27-LHRH and P35-LHRH generated high antibody titres to LHRH. Peptides P35 and P75 generated low antibody titres whereas mice immunised P2, P8 and P62 had undetectable levels of anti-LHRH antibodies (Table 13).
[0097] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
TABLE 13 Anit-LHRH antibody titres in mice immunised with CDV-F derived T cell epitope-LHRH vaccines 4 weeks post first vaccination 2 weeks post second vaccination Groups Mouse 1 Mouse 2 Mouse 3 Mouse 4 Mouse 5 Mouse 1 Mouse 2 Mouse 3 Mouse 4 Mouse 5 Group 1 <100 <100 <100 <100 (control) Group 2 100 126 200 126 200 16,000 16,000 16,000 16,000 16,000 (pool) Group 3 126 400 282 100 282 16,000 16,000 16,000 16,000 16,000 (p25-LHRH) Group 5 <100 <100 <100 <100 <100 1,412 800 <100 <100 <100 (p35-LHRH) Group 6 <100 <100 <100 <100 (p2-LHRH) Group 7 <100 <100 <100 <100 <100 <100 <100 <100 (p8-LHRH Group 8 <100 <100 <100 126 126 <100 (p62-LHRH Group 9 <100 <100 <100 <100 <100 <100 <100 316 3,162 <100 (p75-LHRH
[0098]
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The present invention provides T helper cell epitopes and compositions for use in inducing an immune response comprising at least one of these epitopes. The epitopes are contained within a peptide sequence selected from the group consisting of PRTSDRPVSYTMNRTRS (SEQ ID NO: 4); TRSRKQTSHRLKNIPVH (SEQ ID NO: 5); SHQYLVIKLIPNASLIE (SEQ ID NO: 6); and SPDKLLTFI A SDTCPLV (SEQ ID NO: 25).
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BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to fuel systems and particularly to diesel fuel systems, specifically to systems which separate, monitor, and dispose of water in such diesel fuel systems. More specifically, the invention relates to diesel fuel systems for diesel engines in trucks, busses, boats, construction equipment, and all other uses of diesel engines, both mobile and stationary.
Water accumulates in diesel fuel storage tanks as well as in diesel fuel operating tanks on trucks, busses, boats, construction equipment, and all other uses of diesel engines, both in mobile uses and stationary uses. The water accumulates from rain that leaks into the tanks, ground seepage into tanks, condensation in tanks from moist air, and from other similar causes. It is to be noted that diesel fuel is specified herein, but any type automotive engine fuel is included within the scope and intent of this invention.
When sufficient water reaches the engine parts that are critical in the engine operation the engine stops. In addition, in cold weather in winter or in areas that are habitually cold, the water in these critical engine parts, particularly in the engine mechanisms, such as the injector, the water freezes and prolongs the down-time of the engine. In these latter cases the mechanisms are often damaged by cracking or breaking the parts.
In regard to the above, it is important in completing the mission of the engine that it continue to operate, or be able to operate at a moments notice. Such completion of a mission might be the reaching of a destination by a truck or bus, reaching of a port by a boat or ship, keeping an emergency generating system generating electricity, the ability of an engine to start on command in a hostile environment, and other such situations.
The system of this invention is normally intended for inserting in the fuel line between the fuel pump of the system and the primary filter of the system. The system can be inserted after a regular mechanically operated pump or after an electrically operated pump.
It should be understood that a pump operated by other means, or a system inserted before a pump instead of after the pump, where the pump is capable of draining through the system, are within the scope and intent of this invention.
Included in the system is a sensing unit in a device of the system that senses the level of the water which has been trapped in device and disposes of it.
A test system can be set up to test the invented system by having both a water line and diesel fuel line connected from a water supply and a diesel fuel supply, respectively, to a pump which delivers water and/or diesel fuel to the inlet of the invented system. Valves in each of the two supply lines (water and diesel fuel supply lines) permit selectively controlling a supply of water and/or diesel fuel to the pump. Thus a supply of water and/or diesel fuel may be varied in a zero quantity of either or any percentage of either to make up a 100% total of the mixture supplied 1% and 99%, 50% and 50%, 99% and 1%, and other combinations.
In the system an alternating current (AC) is used across the terminals of the sensing unit instead of a direct current (DC). The reason AC is used instead of DC is because a DC flow of electrical energy will very quickly build up a deposit of insulating matter on one of the two terminals, whereas the use of an AC current keeps the terminals clean. The buildup of insulating matter on one of the two terminals by the direct current in due time, a relatively short time, soon stops the operation of the system. The use of an alternating current prevents such a problem by keeping both terminals of the sensing unit uncontaminated.
The AC is provided by a transformer in a set of logic circuits of the system.
The system can be set up to operate in a 12 volt or a 24 volt system, or modified for any other type voltage system. The device involved is essentially the same in either case.
The important feature of this system is that it disposes of the water at frequent intervals as the monitor senses the level at a critical point for disposal and automatically disposes it. Previously, in the prior art, the engine would stop and the water had to be drained manually from the low-point where it was accumulated.
It is to be noted that water has been specified as the contaminate, but it is to be understood that any electrically conductive contaminate is within the scope and intent of this invention.
This system does not replace the normal fuel filter, the system is inserted ahead of the filter.
It is, therefore, an object of this invention to provide a diesel fuel monitor system for diesel fuel to the water content therein.
It is another object of this invention to provide a diesel fuel monitor system that automatically disposes of water separated from the diesel fuel.
It is still another object of this invention to provide a diesel fuel monitor system operates a sensing system that operates on alternating current to keep the sensing terminals clean of insulating contaminating matter.
It is yet another object of this invention to provide a diesel fuel monitor system that has visual and audible alarm components that provides the status of system in operation.
Further objects and advantages of the invention will become more apparent in the light of the following description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a water separating and disposal device of a diesel fuel monitor system;
FIG. 2 is a side view in partial section of FIG. 1;
FIG. 3 is a front view of a control console monitor of a diesel fuel monitor system;
FIG. 4 is an end view of FIG. 3;
FIG. 5 is a top plan view of an electrical wiring harness for connecting a logic circuits component to a control console monitor component of a diesel fuel monitor system;
FIG. 6 is a perspective view of a case containing logic circuits of a diesel fuel monitor system;
FIG. 7 is a perspective view a reversible mounting bracket for mounting a water separating and disposal device of a diesel fuel monitor system;
FIG. 8 is a top plan view of an electrical wiring harness for connecting a logic circuits component to the electrical connections of a water separating and disposal device of a diesel fuel monitor system; and
FIG. 9 is a schematic diagram of a layout of the components of a diesel fuel monitor system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and particularly to FIG. 9, a diesel fuel monitor system is shown a 5.
In FIGS. 1 and 2, the water separating and disposal device of a diesel fuel monitor system is shown at 10.
Referring to FIG. 9, the major components which make up the diesel fuel monitor system 5 are: the water separating and disposal device 10; a logics circuitry unit 86; a control console monitor 52; an electrical harness 94 to connect the water separating and disposal device 10 to the logics circuitry unit 86; and an electrical harness 78 to connect the logics circuitry unit 86 to the control console monitor 52, and with further connections of the diesel fuel monitor system 5 to the power source 100 of the engine run circuit that includes the fuel pump of the engine run circuit. Details of the aforementioned major components will be described hereinafter.
Turning now to the water separating and disposal device 10 shown in FIGS. 1 and 2, the diesel fuel, hereinafter called fuel, from the fuel pump (not shown) enters the water separating and disposal device 10 through inlet 24 and exits the water separating and disposal device 10 through outlet 28. As the fuel enters inlet 24 it may be contaminated with water. As the fuel leaves outlet 28 it is relatively uncontaminated with water.
The water separating and disposal device 10 is mounted to a suitable support by a reversible mounting bracket 36, which is shown in detail in FIG. 7. As shown in FIGS. 1 and 2, the bracket 36 is shown on a first side of the water separating and disposal device 10 hereinafter called device 10, mounted to the device 10 by the two side arms 42 by means of bolts or machine screws 46 through holes 44 in the side arms 42 and into the top 14 of the device 10. Depending on the location of a selected place for mounting the device 10 and the arrangement of piping and other aspects of the layout, the bracket 36 may be mounted on a second side of device 10 which is opposite to the said first side of device 10. This reversal of position of the bracket 36 might also be referred to as right and left handed mounting. The suitable support to which device 10 is mounted by bracket 36 may be on the engine proper or on an associated structure, such as a truck body, boat bulkhead, or other similar and convenient support. The bracket 36 is mounted to the aforementioned support (not shown) by screws, bolts, or other suitable means (not shown) through holes 40 in the back 38 of bracket 36.
As the fuel enters the inlet 24, it flows downward through the elbow connection (not numbered) on the inlet 24 into the interior of the housing 12 of the device 10. The fuel then flows more or less horizontally across the interior 26 of the housing 12, and then generally upward and out through the elbow connection (not numbered) leading to the outlet 28.
Any water in the fuel as it enters the interior of the housing 12, falls to the bottom of the interior 26 of housing 12 and accumulates on the bottom 16 of the device 10.
The housing 12 may be glass, metal, plastics or any other similar and equivalent material. Metal has the disadvantage that the contents cannot be readily observed, whereas a clear glass or transparent plastics affords excellent opportunity for observing the fuel oil passing through the device 10 and the water accumulated in the housing 12.
The top 14, housing 12, and bottom 16 of device 10 are clamped together and held securely in place by a connecting bolt and nut 18 with suitable gaskets (not shown) to prevent leakage of oil and/or water from the interior 26 of the housing 12 with the top 14 and bottom 16 clamped in place by the connecting bolt and nut 18.
It is to be noted that the top 14 and the bottom 16 may be gasketed screw-type parts to connect to the housing 12 instead of by bolt and unit 18. Such a variation is within the scope and intent of this invention.
A small valve or petcock (not shown) may be installed in the bottom 16 in order to drain accumulated water in cold weather, when the engine is not in operation, and it is necessary to prevent freezing when the engine is idle. That is, water that may not be sufficient to initiate the disposal action of the device 10 before the engine is shut down.
When water accumulates in the lower portion of the housing 12 up to a level that the water reaches the electrode 20, which is spaced from the bottom 16, a circuit is completed through the water from the electrode 20 to either or both the bolt 18 or the discharge pipe 22.
The electrode 20 is insulated under the nut 50 from the top 14. The insulator (not numbered) is shown in FIGS. 1 and 2 under the nut 50 and it extends into the top 14 to provide the insulation.
The bolt 18 and the discharge pipe 22 have a direct connection to the top 14 and through the top 14 and bracket 36 are suitably grounded by the mounting structure.
The electrode 20, insulated from the top 14 is electrically connected to a power source through the electrical lead 48. The electrical lead 48 is incorporated into the wiring of the pigtail electrical harness 98 shown in FIG. 9.
Thus the electrical circuit at the detection of water in the housing 12 is completed through the electrical lead 48 from the pigtail electrical harness 98 to the electrode 20 through the accumulated water in the housing 20, which has reached the electrode 20, to either or both the grounded bolt 18 and/or the grounded discharge pipe 22. The discharge pipe 22 is spaced from the bottom 16 a lesser distance than the electrode 20 is spaced from the bottom 16.
When the electrical circuit is completed through the accumulated water as aforementioned, a signal is sent through the wiring system, lead 48 through the pigtail electrical harness 98, through the electrical harness 94, and through the pigtail electrical harness 90 to the logic circuits 86. The logic circuits 86 relay a signal back through the aforesaid electrical harnesses 90, 94, and 98 and thence through lead wire 32 to the solenoid valve 30, which opens the valve. The circuit being completed therefrom through ground wire 34 via the reference harnesses.
When the solenoid valve 30 opens, the fuel and accumulated water in housing 12, being under pressure by the fuel pump operation, is forced up the vertical discharge pipe 22 within the housing 12, then through the horizontal portion of discharge pipe 22, shown in FIGS. 1 and 2 on the exterior of the top 14, and then vertically downward through the exterior discharge pipe 22, through the open solenoid valve, and is discharged to a suitable receiving means (not shown) for later disposal under proper environmental conditions.
When a sufficient amount of accumulated water is discharged to lower the level of the water below the electrode 20, the circuit is broken and the solenoid valve is closed.
As aforementioned the water detection circuit is powered by an alternating current (AC). The AC is obtained from a transformer in the logic circuits 86, the AC being routed to the electrode 20 via the aforementioned electrical harnesses 90, 94, and 98.
Direction of flow into the fuel inlet 24 and out of the outlet 28 is shown by arrows in FIGS. 1 and 2. In a like manner, the direction of flow of the discharged water is shown by arrows at the discharge pipe 22 in FIGS. 1 and 2.
At the same time as the logic circuits 86 signal the solenoid valve 30 to open, a signal is also sent via pigtail electrical harness 88, through electrical harness 78, through pigtail electrical harness 74, to the control console monitor 52, to light the red alarm or visual indicator lamp 60 to notify the operator that the device 10 is operating to discharge accumulated water. Concurrently, an audible alarm or indicator 62 is sounded when the discharge of accumulated water is taking place. A switch is on the front panel of the control console monitor 52 may be used to turn of the sounding audible alarm. The operations of the control console monitor 52 is, in effect, a readout means to indicate the status of the fuel monitoring system.
The front panel of the control console monitor 52 also has a fuse 56 to protect the circuitry, a green operating light 54 to indicate when the circuits are alive and operational. It indicates when power is on and when operation can be checked. A push button 58 is available to test the circuits and the discharge operation. The push button overrides the circuit through the water and permits manually controlled operation of the solenoid valve, to test/check the operation and to discharge accumulated water in the housing 12, when there is insufficient water to automatically operate the solenoid valve.
The control console monitor 52 has a mounting bracket 64 attached to it that is more or less "U" shaped. The sides 66 of the bracket 64 are arranged so that a pin, stud, or bolt 68 is inserted through the end areas of the bracket 64 to attach or affix it pivotably to the control console monitor 52 so that the console 52 may be positioned in a plurality of positions for viewing. The bracket 64 may also thus be pivotably arranged to be at the bottom side of the control console monitor 52, as shown in FIGS. 3 and 4, or pivotably arranged to be on the top side or rear side of the control console monitor 52.
When the bracket 64 is at the bottom lid of the control console monitor 52, as hereinbefore mentioned, it can be mounted on a suitable top surface, such as a dash board top side or similar shelf-like surface. When the bracket 64 is at the top side of the control console monitor 52, as hereinbefore mentioned, it can be mounted on a suitable underside surface, such as under a dash board or similar over-hang area. Being pivotably attached, the bracket 64 can also be arranged toward the back of the control console monitor 52, as hereinbefore mentioned, and mounted on a wall or other vertical surface as might be available in stationary type installations.
The "U" shaped bracket 64 has holes 72 in the bottom portion 70 of the "U" for suitable mounting means to attach it to a surface as hereinbefore described.
The control console monitor 52 has a pigtail electrical harness 74 extending from it for connecting it to the electrical harness 78 as shown in FIG. 9.
The logic circuits 86 are contained in a separate unit which may be suitably mounted in and on a vehicle, boat, location of a stationary engine, or similar condition. The logic circuits 86 have two pigtail electrical harnesses 88 and 90 extending therefrom. The pigtail electrical harness 88 is connected to the electrical harness 78 and the pigtail electrical harness 90 is attached to the electrical harness 94 all as shown in FIG. 9.
The electrical harnesses aforementioned all have mating electrical plug connectors for making the electrical connections as hereinbefore described. Those mating electrical plug connectors are: pigtail electrical harness 74 on the control console monitor 52 has a plug connector 76a to mate with the plug connector 76b on electrical harness 78, as shown in FIGS. 3, 5, and 9; pigtail electrical harness 88 on the logic circuits 86 has plug connector 84a to mate with plug connector 84b on electrical harness 78, as shown in FIGS. 4, 6, and 9; pigtail electrical harness 90 on logic circuits 86 has plug connector 92a to mate with plug connector 92b on electrical harness 94, as shown in FIGS. 6, 8, and 9; and pigtail electrical harness 98 attached to the electrode 20 by lead 48 and to the solenoid valve 30 by leads 32 and 34, all said leads being from said electrical harness 98, has plug connector 96a to mate with plug connector 96b on electrical harness 94, as shown in FIGS. 8 and 9.
The electrical harness 78 also has two leads 80 and 82 extending from it to connect to the power source 100 in the engine run circuit. The power source designation 100 also includes the operation of the fuel pump, (not shown) which supplies fuel (pure or contaminated with water) from the operating fuel tank (not shown) to the inlet 24 to the device 12 as hereinbefore specified. The leads 80 and 82 extending from electrical harness 78 and connecting to the power source 100 are shown in FIGS. 5 and 9.
It is to be noted that all the aforesaid connector plugs are multi-pole to provide continuity of wiring from, to, and between the respective terminals of the structural parts and entities, as hereinbefore described and specified, so as to provide electrical wiring circuits interconnecting said structural parts and entities for electrical operation as specified.
Accordingly, modifications and variations to which the invention is susceptible may be practiced with out departing from the scope and intent of the appended claims.
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An improved diesel fuel monitor system that determines a specified level of water trapped in a component of the system and disposes of said water, said water having been separated from the fuel being pumped in the engine fuel line hookup. The system consists of a device to monitor the accumulated water level as it rises in the device, said device also being the means for separating said water from said fuel and for disposing of said water, said system includes an electrical wiring circuit, connected to engine run circuit, to operate said device, a set of logic circuits as part of said electrical wiring circuit, and a combined visual and audio monitor console to record status current status of operation of said system.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to radiation sterilization and more particularly to determining a minimal, yet effective, radiation dosage for sterilization.
[0002] Dose setting Methods 1 and 2, used for the validation of a radiation sterilization dose, were developed in the early 1980's. At that time, 2.5 megarads (25 kGy) was viewed as a generally acceptable dose for the sterilization of medical devices. It was recognized, however, that many medical devices would have a sterility assurance level (SAL) of 10 −6 at lower doses and some would require a dose greater than 25 kGy to attain this SAL. Important characteristics of the medical devices used in the developmental work for Methods 1 and 2 were their manufacture in minimally controlled environments, resulting in relatively higher levels and diversity of types of bioburden, and materials of construction that were relatively unaffected by radiation doses of 25 to 75 kGy.
[0003] Many health care products that are currently in development differ significantly from those produced in the early 1980's in that they have one or more bioactive components that are relatively sensitive to radiation damage and they are manufactured in a highly controlled environment which limits the numbers and types of contaminating microorganisms. Often, some or all of the components of these health care products are sterilized prior to introduction into the manufacturing process.
[0004] The key underlying principle of Methods 1 and 2 (see ISO 11137-2, 2006) is the use of direct testing of the radiation response of the product bioburden as part of the determination of a dose to attain an SAL of 10 −6 With both methods, a test is performed where 100 product items are irradiated and a test of sterility is performed at a dose that is expected to result in ˜1 nonsterile item (10 −2 SAL) out of the 100 items tested.
[0005] Method 2B is indicated for “low and consistent bioburden” but these qualitative terms are not strictly defined. With this method, no determination of product bioburden level is made and the radiation dose used for the 100 product items is estimated by the performance of an “incremental dose experiment” (IDE); this method uses an IDE with the following dose values: 1, 2, 3, 4, 5, 6, 7, and 8 kGy. Twenty product items are irradiated at each of these doses and subjected to a test of sterility. The purpose of the IDE is to identify the “first-fraction-positive” (FFP) dose, the first dose where at least one product item is found to be sterile and the remaining items nonsterile (such as 19/20 nonsterile).
[0006] The lowest dose in the IDE whose outcome is 0 + /20 is an estimate of the dose that will yield a 10 −2 SAL. One hundred product items are irradiated at this dose; this test is termed the “verification dose experiment” (VDE). If 0, 1, or 2 positive tests of sterility are observed in the VDE, the delivered dose is termed the “First-No-Positive” (FNP) dose. The determination of the FFP and FNP doses allows, in Method 2, for the calculation of a factor, termed “DS”, that is used to derive a 10 −6 sterilization dose from the experimentally determined 10 −2 SAL dose.
[0007] The difficulty in applying Method 2B for current products with low average bioburden that are manufactured in highly-controlled environments is the manner in which the DS value is calculated. The use of the calculation “DS=1.6+[0.2(FNP−FFP)]” effectively puts a floor on the DS value equal to 1.8 kGy which yields a minimum sterilization dose of 8.2 kGy [sterilization dose =10 −2 dose+4(DS)=1.0+4(1.8)=8.2; FNP=1.0 kGy]. A sterilization dose of 8.2 kGy is overly conservative, for example, for a product with a bioburden of 1.0 composed of microorganisms that are relatively sensitive to radiation. The present invention overcomes the limitations of the methods in the current standards in determining an effective dose for radiation sensitive materials having low bioburdens.
SUMMARY OF THE INVENTION
[0008] A method, according to the present invention, provides for sterilizing objects with radiation. The method comprising the steps of determining a dosage of radiation sufficient to ensure sterilization to a sterility assurance level of 10 −6 and then applying said dosage of radiation to the objects. The step of determining said dosage includes the steps of: determining a bioburden upon one or more samples of the objects; determining an estimate of the dose that results in a probability of 0.01 of a surviving microorganism by testing a quantity of samples of the objects at varying dosage levels of radiation to determine a dosage below which not at all samples are sterilized and above which they are sterilized; confirming the estimate of the dose that results in a probability of 0.01 of a surviving microorganism by testing a quantity of samples of the objects at the dose that was estimated; and calculating a dosage for the sterility assurance level of 10 −6 by adding a factor to the dose that was confirmed to result in a probability of 0.01 of a surviving microorganism and wherein the factor is proportional to the dose that yields a probability of 0.01 of a surviving microorganism and inversely proportional to a log of the bioburden.
[0009] Preferably, the bioburden is equal or less than 20 CFU, and more preferably less than 5 CFU.
[0010] Preferably, the quantity is 100 samples of the objects for confirming that the estimated dose results in a probability of 0.01 of a surviving microorganism.
[0011] Preferably, the factor equals PV*(CD/(2+ log(BB)), wherein PV represents a proportionality value, CD represents the dose that has been confirmed to result in a probability of 0.01 of a surviving microorganism and BB represents the bioburden in colony forming units. Preferably, PV ranges from 1.0 to 10.0. Preferably PV is 2 or greater, more preferably between 2 and 3, with 2.2 being most preferred.
[0012] In one aspect of the invention the object comprises a protein.
DETAILED DESCRIPTION OF THE INVENTION
[0013] A limitation to the use of radiation sterilization is the adverse effects that ionizing radiation may have on the product being irradiated. Similarly steam sterilization cannot be applied to heat-labile product. Heat may also be a limitation for ethylene oxide as well as effects produced from reaction with the gas itself. With modern technology, heat labile or otherwise process-sensitive product may be produced by aseptic processing to a level where a less than one-in-a-thousand items are contaminated. Such product cannot realistically achieve a 10 −6 SAL through aseptic processing, but could, provided that product could stand the necessary radiation dose, be brought to a 10 −6 SAL by a relatively low radiation dose.
[0014] The microbial world contains a vast number of species varying widely in their resistance to ionizing radiation. Although many are extremely sensitive there are some that are very radiation resistant, thus an essential element of any acceptable dose setting method is the inclusion in the process of a step that measures the radiation response of the product bioburden.
[0015] The present invention improves upon prior methods to determine 10 −6 SAL product-specific sterilization dose that has an appropriate level of conservatism. It includes a determination of the bioburden to more accurately calculate sterilization doses in the presence of a low bioburden.
[0016] To determine the sterilization dose according to the present invention it is preferred to select at least 270 product items from each of three independent production batches of a product to be sterilized. The bioburden is determined for each of ten nonsterile selected product items from each batch including the average bioburden per item for each of the three batches and the average bioburden per item for all selected product items. It is preferred to determine the bioburden on individual product items but if the bioburden is too low it is possible to pull ten items from a single batch for the purpose of determining a batch average bioburden. Preferably, bioburden is determined following ISO 11737.
[0017] The average bioburden level for each of the three batches are compared to the overall average bioburden to determine whether any one of the batch averages is two or more time greater than the overall average bioburden. If one or more of the batch averages are two or more times higher than the overall average bioburden then for subsequent calculations the bioburden used should be the highest batch average, otherwise for subsequent calculations the overall average bioburden will be used.
[0018] An IDE is performed by irradiating twenty product items from one of the three production batches at one of a series of not less than eight doses increasing in nominal increments of 0.25 kGy starting at not less than 0.25 kGy. Each of these is monitored with dosimeters. Preferably, the dosages should be within a tolerance of +0.05 kGy or +10%, whichever is greater. The irradiated product items are then tested for sterility and the number of positive tests is noted. Preferably, such testing follows ISO 11737-2.
[0019] The FNP dosage is then determined. For each of the three batches the FNP dose is the lower of two consecutive doses at which all the tests of sterility are negative followed by no more than one further positive test in any of the remaining tests in the incremental dose series. Alternatively, FNP can be determined by finding the lowest dose at which one positive in 20 tests of sterility occurs immediately preceded by one and only one incremental dose at which all tests were negative and followed by incremental doses at which all tests are negative. This information is used to determine a “verification dose” (VD) which is equal to the highest of the three FNP doses.
[0020] The VD is used to perform a VDE in which 100 products from each of the three batches are irradiated at the VD. The tolerances for the VDE should be similar to those in the IDE. The irradiated product items are individually tested for sterility and the number of positive tests recorded no more than two positive tests of sterility should appear for each of the batches.
[0021] This data is then used to calculate a primary D 10 value (PD 10 ) using the formula PD 10 =VD/(2+ log(BB)), where BB is the batch average bioburden in colony-forming units (CFU).
[0022] The present inventors have examined a large number of actual populations and a large series of simulated populations of microorganisms to determine a relationship of the D 10 required to reduce each population over a wide range of bioburden numbers between that yielding a 10 −2 SAL (PD 10 ) and that necessary to reduce the population remaining at the 10 −2 dose to a 10 −6 SAL. The second D 10 is termed the terminal D 10 or TD 10 .
[0023] Populations A through F comprising distributions of resistance of six different microbial populations, and selected modifications thereof, have found use as challenges in computer evaluations of various dose setting and substantiation methods. Population C is the standard employed in dose setting Method 1 and, as such, was designed to represent a highly severe challenge to the radiation sterilization process; in developing the distribution, measurements of the resistance of constituent microorganisms giving D 10 values ranging from 1.0 to 4.2 kGy, were carried out with the organisms dried in the presence of organic material, thereby deliberately creating highly effective radiation protective conditions. Population B represents the resistances of the same microorganisms as in Population C but with resistances measured in the absence of organic solutes; overall, it's response to radiation is somewhat greater than that of Population C, the D 10 range being 0.8 to 3.3 kGy. Theoretical Population A was postulated from Population B to represent a minimal microbial challenge to the radiation sterilization process—it was derived by reducing each of the 9 classes of D 10 values by around 30% while retaining frequencies of occurrence found for Population B. Clearly, the initial selection of Population A is in keeping with the envisaged microbiological status of candidate products to which a new method of dose setting would be applied. D, E and F are populations which possess resistance distributions that exhibit responses to radiation much less than that of Population C and thus are not relevant in the present context.
[0024] The notion of dividing a radiation dose-response curve of a heterogeneous microbial population into two distinct parts was first utilized in the development of Method VD max . In taking this activity forward, it was recognized that, subject to passing the VDE at a specified SAL (generally 10 −2 ), it is solely the response of the microbial population on product surviving at this SAL that sets the sterilization dose to achieve a target SAL somewhat below 10 −2 (generally 10 −6 ). This terminal response is definable quantitatively by the D 10 value derived from the linear line joining the two points (log 10 −2 , dose at 10 −2 ), (log 10 −6 , dose at 10 −6 ); its value has been symbolized by the term TD 10 . The upper part of the dose-response curve, occurring above an SAL of 10 −2 , is similarly definable through a D 10 derived from the line joining the points (log bioburden, dose =0), (log 10 −2 , dose at 10 −2 ), its value being symbolized by PD 10 . This analysis of dose-response curves of Population C is the foundation of Method VD max that is now being applied to the substantiation of a range of sterilization doses extending from 15 to 35 kGy; in this context, it has proved to be both a valuable and valid approach (Note, with Method VD max , verification is performed at an SAL of 10 −1 and, hence, this SAL is the transition point on the dose-response curve for the calculation of values of PD 10 and TD 10 for use with this method).
[0025] Heterogeneous microbial populations with an associated heterogeneous radiation response will generally constitute the bioburden present on product prior to sterilization. Such populations inevitably yield values of TD 10 that exceed those of PD 10 and, hence, give TD 10 /PD 10 ratios that are greater than 1.0. Exceptionally, bioburden may comprise microorganisms of single type exhibiting a homogeneous response to radiation. Homogeneous populations give ratios of 1.0 or, in circumstances where the microorganism's dose-response curve exhibits a shoulder, less than 1.0.
[0026] popA
[0027] For “Population A” (popA), which is heterogeneous, the expectation is for TD 10 /PD 10 ratios to be greater than 1.0 irrespective of the level of bioburden. This was found to be so. TD 10 /PD 10 ratios vary systematically over the bioburden range, 0.02 to 1000, taking a value of 2.01 at the lower limit and 1.67 at the upper while passing through a maximum of 2.18 at a bioburden of 0.50. The existence of a maximum is due to the different rates at which values of TD 10 and PD 10 increase with increasing bioburden. Rounding up of this maximum to a value of 2.2 provides an initial choice of the PD 10 coefficient against which values of TD 10 /PD 10 ratios derived from populations possessing distributions of resistance other than that of popA can be compared.
[0028] popC
[0029] Values of TD 10 /PD 10 ratios for “Population C” (popC), another heterogeneous microbial population, behave in a manner similar to that found for popA with increasing bioburden. For bioburden levels extending from 0.02 to 1000, ratios range from 1.78 to 1.58 with a maximum of 1.92 at a bioburden of around 0.30. popC is the resistance distribution (so-called Standard Distribution of Resistances) on which dose setting Method 1 is founded and its TD 10 /PD 10 ratios are, at comparable bioburden levels, universally less than those of popA, a finding indicating a degree of conservativeness associated with a choice of 2.2 as the PD 10 coefficient.
[0030] popA_MD55 to MD62
[0031] These microbial populations comprise a family developed by the modification of popA. Modification involved shifting systematically to the right the frequency of the highest resistance occurring in popA while reversing the displaced frequencies in ascending order within the eight populations. This gave populations with responses to radiation that progressively decrease with increasing MD designator. As all eight MDs are heterogeneous, they gave values of TD 10 /PD 10 ratios greater than 1.0. For this group of populations with widely varying resistance distributions, no value of the TD 10 /PD 10 ratio was greater than 2.05 for the bioburden range 0.02 to 1000 with the vast majority well below the comparator value of 2.2. In fact, as the overall resistance of the populations increased (in other words, the response to radiation decreased), the ratios approached a value of 1.0, again pointing to the conservative nature of a coefficient of 2.2.
[0032] Other Modified Distributions Derived from popA
[0033] Another means of developing distributions of resistance varying overall from that of the parent distribution is to progressively sum the resistance probabilities, starting with that which takes the lowest value and proceeding to the highest. This provides populations for which responses to radiation are, to varying degrees, either more than or less than that of the parent population. PopA_MD6 and MD9 is one such pair of populations that respond in this opposite way, popA_MD10 and MD14 is another and popA_MD15 and 20 is a third, the population with the higher numerical designator of the pair showing the lesser response to radiation and the difference in response for the paired populations becoming greater as the designator increases. For those modified populations whose response to radiation is greater than that of popA (MD6, 9 and 15), calculated values of TD 10 /PD 10 ratios across the bioburden range 0.02-1000 are all below corresponding values for popA and thus are amply covered by a value of 2.2. In contrast, the populations, which have been modified in a way that provides a proportion of resistant microorganisms in excess of that of popA resulting in a lessened response to radiation, give values of ratios at the low end of bioburden range that are greater than 2.2. For example, a maximum ratio of 2.52 is seen for popA_MD9 at a bioburden of 0.3, 2.76 for MD14 at 0.2 and 3.04 for MD20 at 0.08. Clearly, these findings require consideration in making the final choice for the value of the PD 10 coefficient.
[0034] Miscellaneous Populations
[0035] Seven further populations have been studied. Two, created from each of popA and popC, were developed so that the same probability occurred in each resistance class making up the distribution; they were designated popA_even and popC_even, respectively. Two more populations were modifications of popA and popC. They comprised equal probabilities of each of solely the most sensitive and most resistant classes of the populations and were given designates popA — 50S — 50R and popC — 50S — 50R. Three populations were homogeneous in nature, each comprising a single type of microorganism having a resistance defined by a D 10 value of 0.5, 2.5 or 4.2 kGy; they were designated pop_mono 0.5, 2.5 and 4.5, respectively.
[0036] All seven populations gave TD 10 /PD 10 ratios according to the general expectation noted above. The heterogeneous populations provided a range of values of ratios that varied systematically with changing bioburden level and exhibited a maximum. Furthermore, with the exception of popA — 50S — 50R at a bioburden of 0.02, ratios took values of less than 2.2. The exception resulted from the presence of an unduly low PD 10 value at this bioburden level. The homogeneous ‘mono’ populations all showed TD 10 /PD 10 ratios of 1.0.
[0037] Simulated experiments, employing mixed suspensions of B. pumilus spores and S. marcescens cells irradiated at doses ranging from 0.25 to 1.0 kGy, gave the necessary assurance that detection is technically feasible with these radiation doses. They also demonstrated that an Incremental Dose Experiment employing this dose range could yield an array of fraction positive results from which an estimate of the dose to achieve an SAL of 10 −2 could be obtained.
[0038] The simulated IDE and VDE have demonstrated that associated procedures, as modified, give successful outcomes. Thus, there is good reason to believe that ‘low dose’ IDEs and VDEs carried out on product will be technically-feasible, practical procedures from which meaningful and necessary doses can be identified.
[0039] The TD 10 /PD 10 analysis of popA produced a maximal rounded-up ratio of 2.2 and this value has been set against values of ratios derived from analyses done on a wide variety of populations having substantially different, but often allied, resistance distributions. The general outcome from this comparison is that popC, which has a greater radiation resistance than popA, and most populations with modifications to the resistance distribution of popA provide values of ratios appreciably less than 2.2 over a wide range of bioburden levels. Clearly, this outcome supports strongly the choice of 2.2 as the PD 10 coefficient and underlines the conservativeness of the value. The exceptions to this finding are certain populations possessing distributions in which there are present higher proportions of microorganisms of high radiation resistance than that in popA. Their presence produces principally increases in the values of TD 10 which, in turn, give high TD 10 /PD 10 ratios.
[0040] Given the above exceptions, what has to be considered is the relevance of such distributions to the ‘real world’. At present this is a judgment decision, although it has to be said that, in the light of the stipulated manufacturing conditions and the controls to be imposed on them, the occurrence on product prior to sterilization of microbial populations having a significant number of microorganisms of high radiation resistance is highly unlikely. Moreover, the results of the VDEs will act as a check for their absence. If such microorganisms do occur, they will have to present at a specific bioburden in a proportion in excess of that of popA level for the PD 10 coefficient of 2.2 to be invalid.
[0041] TD 10 is thus assumed to be 2.2 times PD 10 . The sterilization dose to achieve a 10 −6 SAL is then calculated by adding four TD 10 doses to the VD, in other words sterilization dose equals VD plus (4*TD 10 ).
[0042] The sterilization dose is thus the dose used to sterilize the devices in question and provides a sterility assurance level of 10 −6 . The method is recommended for extremely low average bioburdens of five CFU or below. It is useful for sterilization of delicate drugs and radiation sensitive devices.
[0043] Proteins are particularly difficult to sterilize without damage. One particular area of concern for the inventors is the sterilization of blood proteins and plasma proteins. The source of the proteins may be natural (i.e. human, animal), synthetic or recombinant. Blood protein/plasma protein serves as a transport molecule for lipids, hormones, vitamins and metals. They also serve as enzymes, complement components, protease inhibitors, and kinin precursors. Blood protein/plasma protein includes, but is not limited to, albumin, ancrod, batroxobin, collagen, ecarin, elastin, epinephrine, Factor X/Xa, Factor VII/VIIa, Factor IX/IXa, Factor XI/XIa, Factor XII/XIIa, fibrin, ficolin, fibrinogen, fibronectin, gelatin, globin, haptoglobin, hemoglobin, heparinase, inhibin, insulin, interleukin, lamininthrombin, platelet surface glycoproteins, prothrombin, selectin, thrombin, transferin, von Willebrand Factor, vasopressin, vasopressin analogs, procoagulant venom, platelet activating agents and synthetic peptides having hemostatic activity.
[0044] The present inventors are also concerned with sterilization of polymers, and in particular polymers useful in preparing the fabric substrates in wound dressings, which include, without limitation, collagen, calcium alginate, chitin, polyester, polypropylene, polysaccharides, polyacrylic acids, polymethacrylic acids, polyamines, polyimines, polyamides, polyesters, polyethers, polynucleotides, polynucleic acids, polypeptides, proteins, poly (alkylene oxide), polyalkylenes, polythioesters, polythioethers, polyvinyls, polymers comprising lipids, and mixtures thereof. Preferred fibers comprise oxidized regenerated polysaccharides, in particular oxidized regenerated cellulose. The methods of the present invention are expected to be quite useful with the preceding polymers and proteins.
[0045] While the invention has been particularly described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and that the scope of the appended claims should be construed as broadly as the prior art will permit.
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A method provides for sterilizing with radiation objects which have a low bioburden and which are sensitive to radiation. A dosage of radiation sufficient to ensure sterilization without damaging the object is determined by determining the bioburden upon one or more samples of the objects, determining an estimate of the dose that results in a probability of 0.01 of a surviving microorganism by testing a quantity of samples of the objects at varying dosage levels of radiation, confirming the estimate by testing a quantity of samples of the objects at the dose that was estimated; and calculating a dosage for the sterility assurance level of 10-6 by adding a factor to the dose that was confirmed to result in a probability of 0.01 of a surviving microorganism and wherein the factor is proportional to the dose that yields a probability of 0.01 of a surviving microorganism and inversely proportional to a log of the bioburden.
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FIELD OF THE INVENTION
[0001] The invention generally relates to authenticating positioning data, such as Global Positioning System (GPS) data, and more particularly to digitally signing positioning data to facilitate determining authenticity of the data.
BACKGROUND
[0002] Availability of low-cost position determination devices, such as inexpensive GPS receivers, has brought such devices into the hand of general consumers. This has resulted in attempts to leverage the use of such receivers. For example, one such use is to provide offers of goods or services to people that can provide a “track log,” e.g., recorded output from a positioning device, that indicates that one has visited a certain location or otherwise qualified for an offer. Unfortunately, a significant limitation to making such offers based on a track log is that one may fraudulently alter a track log so as to inappropriately qualify for the offer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The features and advantages of the present invention will become apparent from the following detailed description of the present invention in which:
[0004] [0004]FIG. 1 illustrates an exemplary positioning device.
[0005] [0005]FIG. 2 illustrates a system-level data-flow diagram according to one embodiment of the invention utilizing the FIG. 1 positioning device.
[0006] [0006]FIG. 3 illustrates a variation of the FIG. 2 embodiment according to one embodiment of the invention.
[0007] [0007]FIG. 4 illustrates a suitable computing environment in which certain aspects of the invention may be implemented.
DETAILED DESCRIPTION
[0008] [0008]FIG. 1 illustrates an exemplary positioning device 100 . In one embodiment, the positioning device comprises a global positioning system (GPS) detector 102 that operates to obtain geographic location information, hereafter simply “position data,” according to known methods of receiving and interpreting GPS signals. It will be appreciated by one skilled in the art that other position detection technology, e.g., long-range radio navigation (LORAN), Inertial Navigation Systems (INS), etc. may also be used to determine position data.
[0009] As illustrated, the positioning device also comprises an encryption module 104 . The encryption module may be used to encrypt and/or sign position data determined by the GPS, e.g., to encrypt a GPS track log or other position related output from the GPS, using known public key or secret key cryptographic techniques, including block or stream ciphers, hash functions, RSA, Digital Signature Algorithm (DSA), Diffie-Hellman, Data Encryption Standard (DES), MD2, MD4, MD5, and public key cryptography techniques. The encryption module may be implement in software, firmware, or hardware. When the encryption module is implemented in software, the encryption module may be protected from tampering by using known tamper resistant software techniques. In one embodiment, tamper resistant memory 106 is used to store program instructions, processor directives, or the like, for the positioning device.
[0010] In one embodiment, the encryption module 104 digitally signs position data determined by the GPS 102 . In another embodiment, the encryption module encrypts position data into unrecognizable cipher text. In one embodiment, the encryption module digitally signs or encrypts only a portion of position data determined by the GPS. In another embodiment, all position data output from the GPS is digitally signed or encrypted as it is determined by the GPS.
[0011] In the illustrated embodiment, the positioning device 100 also comprises a key memory 108 communicatively coupled with the GPS 102 and encryption module 104 ; the key memory may be permanently affixed to the positioning device, or removably coupled, such as by way of an insertable identification card or the like. The memory may be used to store an encryption key, such as a private key from a pair of asymmetric keys used in a public key cryptosystem, and the memory may be tamper resistant. In one embodiment, the positioning device has an associated serial number 110 that corresponds to a public key which may be used to validate a signature applied with the private key, or to decode data encrypted with the private key. It will be appreciated that the serial number may be encoded in memory and/or affixed to a casing enclosing the positioning device 100 . In one embodiment, the tamper resistant memory 106 and the key memory 108 are a single memory.
[0012] In one embodiment, the manufacturer of the positioning device 100 writes the encryption key, e.g., the private key, into the key memory 108 . The manufacturer then, in essence, acts as a certificate authority (CA) in this security system. A certificate authority issues certificates, which are cryptographically secured data files that identify an entity, such as the manufacturer, that often describe various attributes of the entity, and enable the identified entity to digitally sign or encrypt data such that a signature is traceable back to the entity. In another embodiment, a different entity (not illustrated) acts as a certificate authority in this security system, and the certificate authority provides the manufacturer with the encryption key, e.g., the private key, for storing in the key memory 108 .
[0013] In the illustrated embodiment, the positioning device 100 also comprises an output 112 for providing data, including signed or encrypted position data, from the positioning device to a destination external to the positioning device. It will be appreciated that any form of wired or wireless carrier or network technology may be used to communicate data from the output to the destination.
[0014] [0014]FIG. 2 illustrates a system-level data-flow diagram according to one embodiment of the invention utilizing the FIG. 1 positioning device 100 . As illustrated, a certificate authority 200 sends a manufacturers certificate 202 to a manufacturer 204 of the positioning device.
[0015] The manufacturer 204 may then in turn store the certificate 202 in the key memory 108 so that the positioning device 100 is enabled to digitally sign or encrypt position data. In another embodiment, rather storing a certificate 202 in the memory, instead the manufacturer derives a cryptographic key pairing comprising a public key and a private key based on the certificate, and the private key is stored in the memory. In this latter embodiment, a manufacturer is able to uniquely identify each manufactured device based on the cryptographic key(s) associated with the manufactured device. The key pairing may be derived with respect to the certificate. In one embodiment, the positioning device may be configured such that it operates without signing or encryption capabilities when no certificate or other cryptographic key is present in the key memory.
[0016] Signed position data 206 may then be provided to a service provider 208 , which in turn may review the signed position data and make offers 210 , e.g., to an entity 212 such as a user (assumed for the purposes of this description) or business owning or otherwise responsible for the positioning device 100 . Typically, a service provider is interested in making an offer to users that have been to certain locations that meet offer requirements. For example, in one embodiment, the service provider may want to issue a discount coupon to users known to have frequented a competitor's store. In a further embodiment, the value or nature of the coupon or other offer may be partially or wholly dependent on various factors, such as the frequency of visits to the competitor's store, or the type of other destinations visited by the user. However, before committing to a particular offer, the service provider often wants to validate that a particular user has in fact visited locations meeting the terms of an offer.
[0017] There are various ways to validate a user. For example, if received position data is unencrypted, and appears to satisfy the terms of an offer, the service provider validates the digital signature applied to the position data to ensure that the position data has not been tampered with to satisfy the offer. If the position data appears legitimate, then the service provider may comfortably extend an offer. It will be appreciated that if the position data is encrypted, if it can be successfully decrypted, then this can be viewed as validating the position data, allowing an offer to be extended.
[0018] Once position data, e.g., a GPS track log or other data representing travels, can be verified, many uses of the invention are possible. One such use is defining private clubs based on members having visited certain places, or members having visited certain places within a particular time frame. Another use is, as discussed above, providing special offers for goods, services, coupons, etc., depending on where the position data indicates one has been, e.g., to a competitor's store.
[0019] [0019]FIG. 3 illustrates a variation of the FIG. 2 embodiment. As illustrated, an editor 300 is communicatively coupled between the positioning device and the service provider 208 . In this embodiment, the editor receives a certificate 302 , e.g., an editor's certificate, from the certificate authority and stores it in a key memory 304 in a manner analogous to that discussed above with respect to the FIG. 1 key memory 108 .
[0020] The editor 300 may then be used to edit position data 206 signed by the positioning device 100 , and then sign the edited data to allow confirmation by the service provider 208 or other entity that the output from the editor was not tampered with or otherwise altered. One reason for such editing would be to remove portions from position data not related to satisfying an offer. That is, the editor could determine that the output from the positioning device had not been tampered with, remove unnecessary position data, resign the edited position data, and provide the edited position data to the service provider 206 . Another reason would be to afford privacy, or to comply with privacy policies or other policies or interests of the user 212 .
[0021] By validating the data from the positioning device, the editor addresses the issue of where position data goes to an illicit third party that improperly modifies the position data and then sends it to the editor for signing. In one embodiment, chain of custody information is available to allow a service provider to determine and confirm what entity took what action on the position data.
[0022] It will be appreciated that although both FIGS. 2 and 3 illustrate the positioning device 100 , certificate authority 200 , manufacturer 204 , service provider 208 , user 212 , and editor 300 as separate entities, various other entity combinations may be utilized. For example, as illustrated by the dotted lines, the certificate authority and manufacturer may comprise a single entity 306 , or the certificate authority and the service provider may comprise a single entity 308 , or all three may comprise a single entity 310 .
[0023] [0023]FIG. 4 and the following discussion are intended to provide a brief, general description of a suitable computing environment in which certain aspects of the illustrated invention may be implemented.
[0024] An exemplary environment for embodying, for example, the positioning device 100 of FIG. 1 or the certificate authority 200 of FIG. 2, includes a machine 400 having system bus 402 . As used herein, the term “machine” includes a single machine or a system of communicatively coupled machines. Typically, attached to the bus are processors 404 , a memory 406 (e.g., RAM, ROM), storage devices 408 , a video interface 410 , and input/output interface ports 412 . The machine 400 may be controlled, at least in part, by input from conventional input devices, such as keyboards, mice, joysticks, as well as directives from another machine, biometric feedback, e.g., data incident to monitoring a person, plant, animal, organism, etc., or other input.
[0025] The system may also include embedded controllers, such as Generic or Programmable Logic Devices or Arrays, Application Specific Integrated Circuits, single-chip computers, smart cards, or the like. The system is expected to operate in a networked environment using physical and/or logical connections to one or more remote machines 414 , 416 through a network interface 418 , modem 420 , or other data pathway. Collectively, the input/output ports 412 and connections 418 , 420 comprise exemplary embodiments for the output 112 of FIG. 12. The machines may be interconnected by way of a wired and/or wireless network 422 , such as an intranet, the Internet, local area networks, wide area networks, cellular, cable, laser, satellite, microwave, “Bluetooth” type networks, optical, infrared, or other short range or long range wired or wireless carrier.
[0026] The invention may be described by reference to or in conjunction with program modules, including functions, procedures, data structures, application programs, etc. for performing tasks, or defining abstract data types or low-level hardware contexts. Program modules may be stored in memory 406 and/or storage devices 408 and associated storage media, e.g., hard-drives, floppy-disks, optical storage, magnetic cassettes, tapes, flash memory cards, memory sticks, digital video disks, biological storage. Program modules may be delivered over transmission environments, including network 422 , in the form of packets, serial data, parallel data, propagated signals, etc. Program modules may be used in a compressed or encrypted format, and may be used in a distributed environment and stored in local and/or remote memory, for access by single and multi-processor machines, portable computers, handheld devices, e.g., Personal Digital Assistants (PDAs), cellular telephones, etc.
[0027] Thus, for example, with respect to the illustrated embodiments, assuming machine 400 operates as the positioning device 100 , then remote machines 414 , 416 may respectively be a FIG. 2 certificate authority 200 and a service provider 206 . It will be appreciated that remote machines 414 , 416 may be configured like machine 400 , and therefore include many or all of the elements discussed for machine.
[0028] Having described and illustrated the principles of the invention with reference to illustrated embodiments, it will be recognized that the illustrated embodiments can be modified in arrangement and detail without departing from such principles. And, though the foregoing discussion has focused on particular embodiments, other configurations are contemplated. In particular, even though expressions such as “in one embodiment,” “in another embodiment,” or the like are used herein, these phrases are meant to generally reference embodiment possibilities, and are not intended to limit the invention to particular embodiment configurations. As used herein, these terms may reference the same or different embodiments that are combinable into other embodiments.
[0029] Consequently, in view of the wide variety of permutations to the embodiments described herein, this detailed description is intended to be illustrative only, and should not be taken as limiting the scope of the invention. What is claimed as the invention, therefore, is all such modifications as may come within the scope and spirit of the following claims and equivalents thereto.
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To facilitate an offeror making sensible offers to offerees based on locations visited by offerees, position data from a positioning device, such as a GPS or other positioning device, is digitally signed or encrypted, and provided to an offeror. The offeror may then validate the digitally signed or encrypted position data before extending an offer based thereon. To facilitate digital signing or encryption of position data, an encryption key may be embedded within a positioning device by a manufacture of the positioning device. Various trust models may be employed between the manufacturer, offeror and offerees.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Application No. 2003-70963, filed Oct. 13, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus to develop an image using a two-component developer, and particularly, to an image forming apparatus capable of controlling a linear velocity ratio of a photoconductive drum and a developing roller.
2. Description of the Related Art
A general image forming apparatus, such as electrophotographic laser printer, forms an electrostatic latent image on a photoconductive medium (drum) using an exposure optical system, forms a toner image by developing the electrostatic latent image with a developing apparatus, and fuses the toner image transferred onto a recording paper.
The developer used for the developing apparatus is divided into a one-component developer and a two-component developer. In a case of the one-component developer, the toner particles are electrified by friction among themselves or by friction with a proper electrification member.
The two-component developer is a mixture of magnetic carrier particles and synthetic resin nonmagnetic toner particles, being mixed in a proper ratio. The toner particles are electrified while being mixed with the carrier particles. Thus, the electrified toner particles are transferred to a developing roller together with the carrier, and then adhere to an electrostatic latent image area on a surface of the photoconductive medium to form the toner image.
Meanwhile, a developing method using the two-component developer has been developed. A developing apparatus using the two-component developer comprises a photoconductive drum, a developing roller (a magnet roller) which rotates while maintaining a predetermined developing gap with the photoconductive drum, a doctor blade for cutting the two-component developer attached to a surface of the developing roller in a certain thickness, and a mixer for mixing the two-component developer.
In the above structure, the mixing ratio of the toner to the carrier (T/C) in the two-component developer is less than 5%. That is, if a high-speed printing is performed in a higher T/C toner ratio than 5%, the toner particles scatters and become afloat inside of the image forming apparatus, and therefore, peripheral parts beomces contaminated.
If the T/C toner ratio is decreased, an image density is accordingly decreased. In order to compensate for this problem and to implement a desired image density, in general, the developing apparatus is designed such that a ratio of a linear velocity of the photoconductive drum to a linear velocity of the developing roller is not less than 1 to 2.5. That is, the linear velocity ratio of the developing roller to the photoconductive drum is increased so that the T/C toner ratio is controlled to remain low. Then, during the high-speed printing, the image density can be prevented from decreasing.
However, in the above developing system, if the linear velocity ratio of the developing roller to the photoconductive drum is increased to much, a back portion of the toner image can be torn off with respect to a rotating direction of the photoconductive drum at a certain-thickness font, which is so-called a ‘brush mark’.
More specifically, as shown in FIG. 1 , a toner T adhering to a carrier C, which is electrified to a ‘+’ potential at the developing roller, is transferred to a toner image area 2 a of the photoconductive drum 2 , which is electrified to a ‘−’ potential, to form the toner image. At this time, if a linear velocity of the developing roller 1 to the photoconductive drum 2 is increased, a ‘−’ potential of a non-image area 2 b of the photoconductive drum 2 is increased by a heat increase of the photoconductive drum 2 . Furthermore, the ‘+’ potential of the carrier C on the developing roller 1 increases. Accordingly, the carrier C on the developing roller 1 is pulled to the non-image area 2 b of the photoconductive drum 2 , which has an increased ‘−’ potential. In this process, the carrier C is mashed and scattered about a back portion of the toner T attached to the image area 2 a (‘A’ area in FIG. 1 ).
SUMMARY OF THE INVENTION
In order to overcome the above-mentioned and/or other problems, it is an aspect of the present general inventive concept to provide an improved electrophotographic laser printer capable of controlling a linear velocity ratio of a developing roller and a photoconductive drum to improve quality of a toner image.
The above-described and/or other aspects of the present general inventive concept can be achieved by providing an electrophotographic laser printer that can include a photoconductive drum to form an electrostatic latent image corresponding to a predetermined image by a laser beam scanned after being electrified to a predetermined electric potential, and a developing roller to rotate together with the photoconductive drum having a developing gap therebetween and to transfer a developer, which is a mixture of a toner and a carrier, to the photoconductive drum to form a toner image on the electrostatic latent image, wherein a linear velocity ratio S of a linear velocity Vm of the developing roller to a linear velocity Vo of the photoconductive drum is 1.70 to 1.75.
In an aspect of the general inventive concept, the developing gap can be 0.73 mm to 0.76 mm.
In another aspect of the general inventive concept, the electrophotographic laser printer may further include a mixer to mix the toner and the carrier into the developer, a blade to cut the developer transferred to the developing roller into a predetermined thickness and to be mounted at a predetermined distance from the developing roller. It is another aspect a gap between the blade and the developing roller is 0.75 mm to 0.80 mm.
In another aspect of the general inventive concept, a diameter of the photoconductive drum may not be more than 30 mm, and a diameter of the developing roller may not be more than 25 mm.
In another aspect of the general inventive concept, the developer which is a mixture of the carrier and the toner, may have a 5% to 8% mixing ratio of the toner with respect to the carrier.
In another aspect of the general inventive concept, the photoconductive drum and the developing roller can rotate in an opposite direction to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
These and/or other aspects and advantages of the present general inventive concept 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 schematically shows a state that a toner image is damaged in a conventional electrophotographic printer;
FIG. 2 is a schematic view showing an electrophotographic laser printer according to an embodiment of the present general inventive concept; and
FIG. 3 is a view showing the main parts of FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the embodiments of the present general inventive concept, 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. 2 is a schematic structure view explaining an image forming apparatus, such as an electrophotographic laser printer, according to an embodiment of the present, general inventive concept. In FIG. 2 , a photoconductive drum 10 may be mounted as a photoconductive medium to rotate clockwise. An electrifying roller 12 and a cleaning roller 13 to clean the electrifying roller 12 can be mounted to rotate while contacting each other. A laser-scanning unit 14 can scan a laser beam on a surface of the photoconductive drum 10 electrified to a predetermined electric potential by the electrifying roller 12 and forms an electrostatic latent image.
At a lower part of the printer with respect to the photoconductive drum 10 , a developing unit 20 can be provided to develop a two-component toner on the electrostatic latent image. At an upper part of the printer, a waste toner collecting unit 30 can be provided to remove and collect the toner remaining on the photoconductive drum 10 . Here, the waste toner collecting unit 30 may include a waste toner cartridge 31 , a cleaning blade 32 , a collecting roller 33 , and an auger 34 . A structure of the waste toner collecting unit 30 is generally known, and therefore a detailed description thereof will be omitted.
The developing unit 20 may include a developing cartridge 21 to receive the two-component developer D, a supplying roller 22 , a mixer 23 , a developing roller 24 , and a blade 25 .
The two-component developer D can be made by mixing magnetic carrier particles and nonmagnetic toner particles in a predetermined mixing ratio. According to this embodiment of the present general inventive concept, a mixing ratio T/C of the toner T with respect to the carrier C may be 5% to 8%. Thus, if the ratio T/C of the toner T to the carrier C is controlled to be lowered, the toner can be prevented from scattering and becoming afloat in an inside of the printer even during a high-speed printing. In addition, according to a characteristic structure of this embodiment, a desired image density can be obtained even if the T/C ratio is lowered.
The developer D of the above mixing ratio can be supplied from the supplying roller 22 to the mixer 23 . The mixer 23 can rotate to mix the toner T and the carrier C. In this process, the carrier C and the toner T can be electrified by a friction of the carrier C and the toner T For example, the carrier C can be electrified to a ‘+’ potential, and the toner T can be electrified to a ‘−’ potential. In an aspect of the general inventive concept, the carrier C and the toner T can be electrified alternatively, for example, by changing a material thereof. In this embodiment, the carrier C can be electrified to the ‘+’ potential, and the toner T can be electrified to the ‘−’ potential. Meanwhile, the toner T particles electrified to the ‘−’ potential can adhere to a surface of the carrier C particles which are electrified to the ‘+’ potential. Therefore, the developer D can maintain a regular mixing ratio. The mixed developer D can adhere to an outer circumference of the developing roller 24 .
The developing roller 24 may be a magnet roller including a magnet 27 therein, and made of an electrically conductive metal. The developing roller 24 can be directed toward the photoconductive drum 10 with a predetermined developing gap G 1 , as shown in FIG. 3 , and can rotate in an opposite direction to the photoconductive drum 10 , that is, counterclockwise. Accordingly, the developer D including the magnetic carrier C can adhere to the surface of the developing roller 24 by a magnetic force of the magnet 27 . In an aspect of the general inventice concept, the developing roller 24 and the photoconductive drum 10 can be electrified to the ‘−’ potential of a predetermined level.
The blade 25 can cut the developer D adhered to the developing roller 24 into a predetermined thickness. Therefore, the blade 25 can be mounted to have a predetermined gap G 2 , and the predetermined gap G 2 can range from 0.75 mm to 0.80 mm. Accordingly, on a surface of the developing roller 25 that has passed the blade 25 , the developer D-can adhere to the developing roller 25 to form a layer having a thickness of approximately 0.75 mm to 0.80 mm.
Additionally, the developing gap G 1 between the developing roller 24 and the photoconductive drum 10 may be 0.73 mm to 0.76 mm. That is, the developing gap G 1 can be smaller than the gap G 2 such that the thickness of the cut developer D is larger than the developing gap G 1 to enable a normal development.
Furthermore, in the above structure, the photoconductive drum 10 and the developing roller 24 may have small outer diameters as much as possible to realize a compact-sized developing unit 20 and a printer. It has been determined by experiments by the inventor herein that the photoconductive drum 10 should have an outer diameter of not more than 30 mm, and that the developing roller 24 should have an outer diameter of not more than 25 mm according to an embodiment of the general inventive concept.
In addition, in order to overcome a ‘brush mark’ which is a problem of a conventional printer, a photoconductive drum linear velocity Vo and a developing roller linear velocity Vm should have a ratio of 1:1.70˜1.75. In other words, when the linear velocity ratio S, which is Vm/Vo, is 1.70/1 to 1.75/1, the ‘brush mark’ can be prevented and the desired image density can be obtained. Especially, in a case that an outer circumference of the photoconductive drum 10 is 30 mm, an outer circumference of the developing roller 24 is 25 mm, the developing gap G 1 is 0.73 mm to 0.76 mm, and the gap G 2 is 0.75 mm˜0.80 mm, the best image quality can be obtained.
Table 1 below is a quality evaluation of the toner image which is developed on the photoconductive drum 10 according to the linear velocity S.
TABLE 1
velocity ratio (Vo:Vm)
Image evaluation (brush mark)
1:1.5
X
1:1.7
□
1:1.75
◯
1:1.9
X
1:2.0
X
1:2.25
XX
In the above Table 1, the image evaluation was accomplished by measuring an image area through an optical microscope.
O: The brush mark of the image is not found. □: The brush mark of the image partially occurs. X: The brush mark of the image apparently occurs.
According to the Table 1, when the velocity S is controlled to be 1.70 to 1.75, a high-quality image can be obtained without the brush mark occurred.
As described above, according to an embodiment of the electrophotographic laser printer, an image density deterioration and a brush mark appearance can be prevented by controlling a linear velocity ratio of a photoconductive drum and a developing roller to a predetermined value without increasing the ratio T/C.
Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
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An image forming apparatus having a photoconductive drum to form an electrostatic latent image corresponding to a predetermined image by a laser beam scanned after being electrified to a predetermined electric potential, and a developing roller to rotate together with the photoconductive drum having a developing gap therebetween and to transfer a developer, which is a mixture of a toner and a carrier, to the photoconductive drum to form a toner image on the electrostatic latent image, wherein a linear velocity ratio of a linear velocity of the developing roller to a linear velocity of the photoconductive drum is provided at a predetermined ratio, which provides maximum quality of the toner image.
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BACKGROUND OF THE INVENTION
The present invention relates to bibs, and in particular, to a disposable bib with torso side catch pockets, an improved bottom catch pocket and an improved neck opening directing the flow of matter into the pockets.
Based upon my experience as a Dietician wherein I have assisted in providing meals in medical care settings, there appears to be a serious problem with spillage when patients are served meals while in a semi-reclined position in a bed or special chair or other supporting device. Generally, bibs are used to meet the need of protecting the underlying garments of a wearer, be it a child or adult, from liquid or solid spills. Despite the multitude of bibs that are available, very few prove to be effective to protect the garments as well as the surrounding areas of the elderly, convalescing adults, and children from both liquid and solid spills during meal consumption, especially individuals in a medical care setting. Bedridden, convalescing, and handicapped individuals most often consume meals in a semi-reclined position from a bed or in a variety of specialized chairs. The meal is most often served on a tray placed on what is commonly known as a tray table. Most spillage for these individuals is due to poor control of eating utensils, poor body posture, and drooling which results in soiling of the neck and upper chest area. Use of most bibs in this setting appear to be only minimally effective when liquids and solids fall in the upper chest and neck area and gravitate down and to the sides. Thus, excessive soiling of garments as well as soiling of bedding, chairs, flooring and such remains a problem. Also, when excessive spills occur in medical care settings, they require an undesired increase in multiple care providers' time to clean the individual, change their garments, the bedding, and re-sanitize floor areas. Since there is limited health care funding, there is a need to help control health care costs by containing spillage during meal consumption.
Disposable bibs with and without pockets are in common use. Disposable bibs without pockets generally shield only the front of garments. They retain very limited amounts of liquid spills, most often in a semi-absorbent material. Since they do not have pockets, they fail to contain solid spills that gravitate downwardly and to the sides. Disposable bibs with bottom edge catch pockets make an attempt to catch both solids and liquids that gravitate downwardly, but quite often there is a problem in keeping the bottom catch pocket open to catch the spillage. Many bottom catch pockets are effective in a gravitational catch if the wearer is sitting upright at a 90 degree angle with the bib torso length, and the bib planar surface are such that a pocket of adequate width, depth, and height remains fixed in an open position precisely under the spill. Since many convalescing and other individuals must eat their meals while in a semi-reclined position, the amount of soiling of garments and surrounding dining areas remains to be a problem, as evidenced by the large number of various bibs made to solve this problem. Yet, while some advancements have been made in attempts to keep the bottom catch pocket open, they still fail to contain the gravitational upper chest side spills that often occur when an individual is consuming a meal in a semi-reclined position, such as those in medical care settings.
Furthermore, flat planar bib surfaces, with or without a catch pocket at the bottom edge, often become distorted on physically developed adults. This distorted surface area generally results in less frontal protective surface area for splashes whereas spills gravitate to the sides, soiling garments and surrounding areas.
A bib that offers a snug fit at the neck opening to protect from spillage and drooling is often desirous. Drooling is a common occurrence in many post-operative, post-stroke patients and the elderly. While snug fitting, the neck opening still needs to be adjustable to accommodate various neck sizes. Risk of choking then becomes a serious problem, but can be greatly reduced by the elimination of not only strings and ties around the neck, but by also eliminating other mechanisms of hook loop and fasteners. Loops that completely encircle the entire neck region, present a high risk of choking if they are pulled on. Similar problems are relative to complete closures around the neck area which are not desirous, such as for those with surgical sites, intravenous therapy, tracheas and such in the neck region.
It would appear that an inexpensive, disposable bib having an improved neck design, in combination with connected side and bottom catch pockets, would eliminate the need for well-known, more expensive multi-layered bibs. A proposed disposable bib having open side and open bottom pockets would catch and contain spills and thus would decrease manufacturing cost as opposed to the multi-layered bibs. Thus, it would appear that side pockets would be a needed improvement on disposable bibs to help catch and contain spills for those in semi-reclined and other positions for all of the reasons listed above.
Although some known bibs have external fastening devices to an exterior surface area to hold the bottom catch pocket open, they fail to provide any method for containing upper torso spills for a wearer in a semi-reclined position. It is known that bib lower catch pockets with attachment points to tables and chairs can be compromised with body movement. It would appear that if the bottom catch pocket could be held open in conjunction with adjoining open side pockets by means of a unique construction, it would give additional flexibility to the bib. This should provide freedom of movement generally, not previously available. Thus, it appears that open bilateral side catch pockets would be needed, in addition to an open bottom catch pocket to improve the intended function of the bib. Whereas the pockets on the right and left sides of the proposed invention allow for the patient's movement while maintaining the effect and holding capacity of the catch areas.
It does not appear that there is a bib with a neck design that provides means for directing spills and solids to a number of catch pockets. Also, it does not appear that there is a neck design in communication with bilateral open side pockets and an integrally open bottom catch pocket containment areas for spills to protect both the wearer's garments and their immediate surrounding area.
Accordingly, it is seen that a need remains for a bib which not only protects a wearer from spillage, but also collects the spilled food. In order to accomplish this, it is evident that there is a need in the art for an improved bib construction. Although there are a multitude of bibs available, it remains that they fail to catch and contain both solid and liquid spills for those persons in a semi-reclined position during meal consumption. No known bib overcomes the interworking dynamics of a semi-reclined person positioning and movement as does the proposed bib.
SUMMARY OF THE INVENTION
In accordance with the present invention, an improved disposable bib is provided that overcomes the deficiencies of prior art disposable bibs for protecting the garments and the surrounding areas of an individual in a semi-reclined position in a bed or while sitting in a specialized chair. The improved bib provides a sheet of flexible impervious material, adapted to overlie a frontal portion of the patient's torso. The flexible sheeting having upper and lower ends which can be made from a unitary blank. A bottom open catch pocket having a transverse opening extending the full width of the lower end adapted to catch spilled liquid and falling food. Opposing bilateral open side catch pockets extending downwardly on opposite sides of the sheeting integral with the bottom catch pocket are adapted to catch spilled liquid and food along the sides of the sheeting and to direct the material into the adjoined lower end open bottom catch pocket. Cut out U-shaped neck elements at the upper end of the sheeting are configured to fit under the chin and only around the front neck area of the patient. The neck elements gathered design provides means for directing the spillage into the opposing sides and the bottom catch pockets. The sheeting preferably can be formed from a unitary blank of thin flexible plastic wherein the opposing sides and the lower end can be folded inwardly to form open integral catch pockets whereas the upper end can be cut-out to form the neck elements.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described by appended claims in relation to description of preferred embodiments with reference to the following drawings which are explained briefly as follows:
FIG. 1A is a front side elevational view of a patient in a semi-inclined position wearing a bib.
FIG. 1B is a view of a plastic sheet with fold lines for the bottom pocket.
FIG. 1C is a view of the bottom pocket and gathering means at the neck and at the side pockets.
FIG. 2A is a side view showing the accordion configuration pockets integrally joined to the bottom pocket.
FIG. 2B is a fragmentary view illustrating the accordion side pockets.
FIG. 3A is a view of a plastic blank showing cut-lines and fold lines.
FIG. 3B is a view showing initially forming side and bottom pockets.
FIG. 3C is a view showing initial creasing of side wall elements.
FIG. 3D is a view showing the formed bottom pocket integral with adjoined side walls.
FIG. 4A is a view showing joined plastic blanks.
FIG. 4B is an exploded view of the remnants.
FIG. 4C is a view of joined arcuate side remnants.
FIG. 4D is a view of the side pockets integrally joined with the bottom pocket.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention provides an inexpensive disposable thin plastic bib reliably attachable to a patient's clothing or pillow or other backing while the patient is reclining in a semi-reclined position. The present bib uniquely provides in combination, an improved contoured gathered neck design creating a concave plastic body surface providing conduits directing spilled liquids and solids into fixedly engaged open upper torso bilateral side catch pockets and integrally joined transverse bottom catch pocket.
Referring to the drawings, FIG. 1A illustrates a preferred embodiment of the invention showing a patient reclining in a semi-reclined position wearing a bib 10 . The bib is made from a liquid impervious material such as a thin plastic sheet, preferably polyethylene or similar thin impervious material. Commercial pressure sensitive adhesive tabs 12 or similar attachment are provided on opposite sides of shoulder elements 14 to adhere to the patient's clothing, pillow, bedding, chair or other backing. A peel-off backing may be used to preserve the adhesive until use.
In a preferred embodiment depicted in FIG. 1A, the upper cut-out, arcuate shaped neck receiving portion 16 is contoured to fit under the chin and around the front of the neck, as shown. The periphery of neck portion 16 is encompassed by embedded gathering means 18 , such as elastic or webbing, which encircles and pinches the rim creating a concave upper torso area 20 in the plastic body and multiple conduits 22 which direct the flow of spillage into side pockets 24 and integral transverse bottom pocket 26 . Illustrated in FIGS. 1B and 1C is how flat plastic panel 28 is adapted to form the bib seen in FIG. 1 A. Panel 28 , as shown in FIG. 1B, includes cut-out neck 16 , shoulder elements 14 , adhesive tabs 12 , flap tabs 13 and fold line 30 . Opposing flap tabs 13 which are conventional adhesive tabs are located in the shoulder area and at opposing bottom side edges on either side of fold line 30 . As seen in FIG. 1C, bottom pocket 26 is formed by turning upwardly bottom pocket front section 34 and adhering the opposing bonding flap tabs 13 together by thermal bonding, adhesive or similar means. Upper side pockets 38 are formed by folding inwardly upper side elements 36 and thermally or otherwise bonding by flap tabs 13 . Gathering means 18 , such as elastic or webbing, is embedded in the rim of neck cut-out 16 , thereby crimping inwardly the attached plastic body forming a concave surface 20 having rippled conduits 22 . Further gathering means are embedded lengthwise to the side edges of the opposing sides, crimping inwardly, forming crimped open side pockets 24 integral with and forcefully opening transverse bottom pocket 26 . As seen with neck gathering means 18 , the gathering means embedded in the side edges of side pockets 24 likewise form a concave 20 surface in the plastic sheet making substantially the entire surface concave with a multiple of conduits 22 directing the spillage into the pocket.
Another preferred embodiment of the invention is shown in FIG. 2 A. In this embodiment, opposing pleated side pockets 24 are prepared by first folding the bilateral side edges back and forth upon themselves providing accordion shaped side elements 25 , as shown. The terminal ends of each accordion-shaped element are then adhered to the plastic sheet by adhesives, thermal bonding, or other adhering means. The opposing accordion side elements provide a multiple of V-segments 27 , depicted in FIG. 2B fragmentary side view designed to expand the pleated pockets, thereby expanding the side pockets upwardly with overlapping open V-segments provided to catch and direct the spillage into an open bottom pocket. Bottom pocket 32 is formed by folding upwardly front panel 34 and adhering to the opposite side pockets by adhesives, thermal bonding, or similar adhering means. Bottom pocket 32 is secured to the accordion side pockets in a substantially locked, open position by being integrally joined thereto.
A further preferred embodiment providing side pockets and adjoining transverse bottom pocket is best described in FIGS. 3A to 3 D. As seen in FIG. 3A, bib blank 29 includes an elongated rectangular sheet 40 with lengthwise side edges 42 and longitudinal bottom edge 44 . Shoulder elements 14 are formed by discarding top side remnants 46 . Opposing bottom tab elements 48 , shown in FIG. 3B, fold inwardly to the midpoint of sheet 40 as the initial step in forming the bottom pocket. Forming the side pockets is depicted in FIGS. 3B through 3C. Opposing side pocket elements 50 are folded upwardly along fold lines 52 and creased inwardly at crease and attached at line 53 , creating expanded V-configured side elements. The side pocket elements are integrally joined with the bottom pocket by folding elements 56 and 54 upwardly along fold lines 30 to overlap element 48 . The bottom pocket and lower side elements 50 are interconnected and reinforced by bottom element 54 extending over interior bottom element 48 and lower side elements 50 .
As depicted in FIGS. 4A to 4 D, the bib is illustrated being fabricated from adjoining plastic blanks 58 , generally removed from a plastic roll, not shown. In this embodiment, arcuate-shaped remnants 62 are cut lengthwise from neck remnants 60 , cut from adjoining plastic blanks 58 . The arcuate-shaped remnants are adhered to opposing side edges of the blank as seen in FIG. 4 C. Bottom panel 64 is folded upwardly through fold lines 30 and secured to the lower edges of arcuate-shaped remnants 62 by adhering means forming side pockets 24 and bottom pocket 32 as shown in FIG. 4 D. Attachments of gathering means embedded in the cut-out neck and side pockets, as previously described, enhance the formation of the concave plastic body area, thereby directing the spillage into the side pockets and bottom pocket.
While the above descriptions and drawings are specific to the preferred embodiments, it will readily be seen that many other variations of the invention within the scope of the appended claims will be apparent to those skilled in the art once the principles described herein are understood.
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A disposable bib for protecting individuals primarily postured in a semi-reclined position, such as those in medical care settings. The bib includes a plastic body having a gathered neck opening, opposing forcefully open side catch pockets and an integrally joined transverse open bottom pocket. The bib is fabricated to provide concave body portion with rippling conduits which direct spillage into the pockets.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel injection valve device for use in, for example, automobile engines and, more particularly, to a fuel injection valve device provided with a nozzle hole plate for atomization of fuel.
2. Description of Related Arts
Under the recent trend of tightening the regulations of exhaust gas, in the field of fuel injection valve device for use in automobile engines, it has been increasingly demanded to improve fuel spray characteristics. To cope with this demand, several attempts of fuel injection valve device have been proposed. In those known fuel injection valve devices, a nozzle hole plate having a plurality of nozzle holes on the downstream side of a valve member consisting of a valve disc and a valve seat is disposed so that atomized fuel is injected from every nozzle hole into each cylinder head of an engine.
For example, the Japanese Patent Publication (unexamined) No. 2004-169572 discloses a fuel injection valve device in which a first nozzle hole plate having vertical cylindrical holes is joined by welding on the tip (downstream side) of the valve member, and a second nozzle hole plate having an inclined cylindrical holes that are larger hole diameter than the mentioned vertical cylindrical holes and communicate with the cylindrical holes of the mentioned first nozzle hole plate is further welded in a superimposed manner on the downstream side of the mentioned first nozzle hole plate, thereby atomization of fuel being carried out.
The Japanese Patent Publication (unexamined) No. 2003-206828 discloses another fuel injection valve device provided with a valve seat for discharging or interrupting the fuel from the injector by engaging or disengaging with a valve seat moving up and down; and a nozzle plate (nozzle hole plate) having a plurality of orifices directly welded and fixed onto the valve seat on the downstream side; and in which the mentioned orifices are shaped into a circular corn spreading toward the downstream side; thereby atomization of fuel and improvement in quality of exhaust gas being achieved.
The Japanese Patent Publication (unexamined) No. 317607/1997 discloses a further fuel injection valve device in which a nozzle plate (nozzle hole plate) is cup-shaped, and a protruding face of a bottom part of this nozzle plate is welded onto a sleeve fixed to a valve member side so as to press the protruding face on the end face of an opening of the valve member, thereby it being avoided to directly fixing the nozzle hole plate to the valve member in order to suppress deflection produced on the bottom part of the mentioned nozzle plate due to fuel injection pressure.
SUMMARY OF THE INVENTION
To improve fuel spray characteristics such as atomization in the fuel injection valves, it has been conventional to adopt such means as increasing fuel pressure, thinning a nozzle hole plate or the like. In such means, however, the fuel injection valve for cylinder injection of fuel is normally high in fuel pressure (for example, 20 MPa), and therefore when thinning the nozzle hole plate, deflection of the nozzle hole plate becomes large due to application of fuel pressure. Thus, a problem exists in that stress concentration is easy to occur at a notch part between the nozzle hole plate and the weld part of the nozzle. To cope with this, it has been necessary to increase strength of the nozzle hole plate, which eventually results in a large-scaled fuel injection valve.
In the case of the fuel injection valve device disclosed in the Japanese Patent Publication (unexamined) No. 2004-169572, the welding and fixation are made only at the end part of the valve member 5 and the end face of the fitting part of the second nozzle hole plate 9 . In the case of the fuel injection valve device disclosed in the Japanese Patent Publication (unexamined) No. 2003-206828, the welding and fixation are made (from underside) only at the end face of the fitting part of the nozzle plate (nozzle hole plate) 24 fitted to the end part of the valve seat 16 . Furthermore, in the case of the fuel injection valve device disclosed in the Japanese Patent Publication (unexamined) No. 317607/1997, the nozzle plate (nozzle hole plate) 61 and the sleeve 71 welded to the valve member 26 (at the weld part 91 ) are welded only at the outer circumference (at the weld part 92 ). In every foregoing art, the welding of the nozzle hole plate is made only at the end face or on the side face, and a notch part remains at the tip of the nozzle hole plate. Therefore, a stress concentration takes place at this notch part, which may result in a fatigue failure even in case of a minute deflection due to moment of the nozzle hole plate caused by high fuel pressure. Thus, there has been a limit in application of high fuel pressure or thinning the nozzle hole plate.
The present invention was made to solve the above-discussed problems, and has an object of providing a fuel injection valve device capable of thinning a nozzle hole plate and expanding a adjustable range of fuel spray characteristics by a construction for reducing stress concentration that occurs at the weld part of the nozzle hole plate.
A fuel injection valve device according to the invention includes: a nozzle having a fuel passage inside thereof and in which a valve seat is formed at an end; a needle valve for opening and closing the mentioned fuel passage by coming in contact with and separating from the mentioned valve seat; and an nozzle hole plate that is disposed at the tip of the mentioned nozzle and injects a fuel in the mentioned fuel passage at the time of opening the mentioned needle valve. The mentioned nozzle hole plate and the nozzle are fixed by welding in a state of forming an even gap between them.
In the fuel injection valve device of above construction according to the invention, since coefficient of stress concentration applied to a notch part at the tip of the weld part can be made small, deflection of the nozzle hole plate is suppressed and moment produced at the time of welding is made small. As a result, there is an advantage such that thickness of the nozzle hole plate can be established as small as possible even in case of high fuel pressure.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view showing an entire construction of a fuel injection valve device according to Embodiment 1 of the present invention.
FIG. 2 is an enlarged view showing an essential part of a tip part of the valve device of FIG. 1 .
FIG. 3 is a partially enlarged view to explain a state of a valve seat and a nozzle hole plate mounted on the tip part of a nozzle member of FIG. 2 .
FIG. 4 is a graphic diagram of stress produced at the tip of the weld part at the time of operating the fuel injection valve according to Embodiment 1 of the invention.
FIG. 5 is an enlarged view showing an essential part of a tip part of the valve device according to Embodiment 2 of the invention.
FIG. 6 is a partially enlarged view to explain a state of a valve seat and a nozzle hole plate mounted on the tip part of a nozzle member according to Embodiment 3 of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
Embodiment 1 of the invention is hereinafter described with reference to the accompanying drawings. FIG. 1 shows a longitudinal sectional view of an entire construction of a fuel injection valve device according to Embodiment 1 of the present invention, and FIG. 2 shows an enlarged view of an essential part of a tip part of the valve device of FIG. 1 . Referring to FIGS. 1 and 2 , a fuel injection valve 1 mainly consists of a housing 2 , a nozzle member 3 disposed inside at the end part of this housing 2 , and a solenoid part 4 disposed inside at the intermediate part of the housing 2 .
The mentioned housing 2 consists of a yoke part 5 having a flange 5 a for mounting the fuel injection valve 1 on a cylinder head 20 , and a holder 6 connected to one and of the yoke part 5 . The mentioned nozzle member 3 is shaped into a cylinder provided with steps, and consists of a nozzle 9 to which a valve seat 7 and a nozzle hole plate 8 are fixed at the tip by a later-described method; a needle valve 11 that is slidably inserted in the mentioned nozzle 9 so as to open and close a valve seat contact part 10 by moving up and down on the center axis C of the mentioned valve member 3 ; and a moving iron core 12 joined by welding to the mentioned needle valve 11 at the upper end thereof.
The mentioned solenoid part 4 consists of a coil 13 on which copper wires are wounded; a cylindrical stationary iron core 14 mounted on the inner circumference of the mentioned coil 13 ; a rod 15 fixed to the internal part of the mentioned stationary iron core 14 ; a compression spring 16 disposed between an end of the mentioned rod 15 and an end of the needle valve 11 to urge the needle valve 11 on the valve seat 7 ; and a terminal 17 for connecting a lead wire of the coil 13 to outside via a housing part 18 .
Now, operations of the mentioned fuel injection valve 1 are described. When a valve opening signal from a controller (not illustrated) is inputted via the terminal 17 to the coil 13 , magnetic flux generated in the coil forms a magnetic circuit consisting of the stationary iron core 14 , moving iron core 12 , holder 6 and yoke part 5 , and generates an electromagnetic force attracting the moving iron core 13 to the side of the stationary iron core 14 . By the moving up action of the moving iron core, the needle valve 11 also moves to the side of the stationary iron core 14 , thus valve opening of the nozzle member 3 being performed. At this time, an opening area of the valve seat contact part 10 is determined by a lifting amount that is regulated by contact of the valve 11 with a stopper 19 .
On the other hand, when the valve opening signal is inputted from the controller, the conduction of current to the coil 13 is interrupted, and the mentioned electromagnetic attraction is vanished. Accordingly, the moving iron core 12 and the needle valve 11 are moved away from the side of the stationary iron core 14 by the urging force of the compression spring 16 , thus valve closing of the nozzle member 3 being performed.
Fuel injection is carried out when the tip of the needle valve 11 of the fuel injection valve 1 releases the valve seat contact part 10 . As for the sealing force of the needle valve 11 , the compression spring 16 disposed in the internal part of the mentioned stationary iron core 14 is set to a predetermined compressive force by the rod 15 . Accordingly, a sealing force is determined depending upon a compressive force of the compression spring 16 and a fluid force produced by a fuel pressure applied to the seat area of the valve seat contact part 10 .
In addition, the fuel injection valve 1 is mounted on the cylinder head 20 via a ring 25 of Teflon (registered trademark). This ring 25 seals combustion flame within the engine cylinder. However, a nozzle part located under the ring 25 is exposed to the flame.
FIG. 3 is a partially enlarged view to explain a state of mounting the valve seat 7 and nozzle hole plate 8 on the tip part of the mentioned nozzle member 3 . In the drawing, first the valve seat 7 is laid out concentrically with the nozzle hole plate 8 , and the valve seat 7 having been welded on the nozzle hole plate 8 at the outer circumference (indicated by the weld part 21 ) is press-fitted to the nozzle 9 . At this time, note that only the valve seat 7 is press-fitted, so that a step 22 is formed on the nozzle 9 , thereby an even gap g being formed on the entire circumference. Such a gap g is formed on the outer circumference of the nozzle hole plate 8 for the purpose of absorbing the eccentricity between the nozzle hole plate 8 and the valve seat 7 and, at the same time, suppressing the stress concentration on the weld part.
That is, the nozzle hole plate 8 and the valve seat 7 are joined at the periphery thereof through the weld part 21 . It is, however, very difficult to lay out the nozzle hole plate 8 and the valve seat 7 accurately in a perfectly concentric manner, and actually an eccentricity is somewhat produced. As a result, a slight displacement comes out at any part of the periphery. When press-fitting such eccentrically jointed member into the nozzle 9 , a strain stress toward the joint portion will be disadvantageously produced. To avoid such disadvantage, only the valve seat 7 is press-fitted, so that an even gap g is formed on the entire circumference. In addition, the gap g is set to have dimensions enabling to weld, e.g., not more than 0.2 mm in difference of diameter. By seal welding between the ends of the nozzle hole plate 8 and the nozzle 9 , the mentioned gap g is completely closed with welding beads. This portion is indicated by weld part 23 .
End of the mentioned weld part 23 is not a conventionally notch-shaped but is U-shaped having a certain radius of curvature, so that coefficient of stress concentration is small. Accordingly the stress produced at the end of weld part can be made small. Further, by making a radius of curvature larger, the coefficient of stress concentration can be made smaller. Furthermore, since the nozzle 9 and nozzle hole plate 8 are joined together by welding through the gap g thereby being U-shaped at the weld part, the conventionally employed equipment can be used as they are. In addition, under the conditions of different welding depth between the nozzle 9 and nozzle hole plate 8 including a case of large difference in physical properties of material between them or a case where a target welding position is extremely displaced toward the nozzle 9 side or the nozzle hole plate 8 side, any notch may be produced. Accordingly, it is desirable that the nozzle 9 and nozzle hole plate 8 are composed of the same material by adopting, for example, austenitic stainless steel, ferritic stainless steel, or martensitic stainless steel. It is also desirable that the target welding position is located between the nozzle 9 and nozzle hole plate 8 .
As described above, according to Embodiment 1 of the invention, the valve seat 7 and the nozzle hole plate 8 are welded at the outer circumference thereof, thereby forming stepped hole laid out so as to fit only the valve seat 7 to the nozzle 9 , and then the nozzle hole plate 8 and the nozzle 9 are welded so as to have an even gap g between them. In this manner, a weld part moderating the notch is obtained, whereby coefficient of stress concentration on the notch can be reduced. As a result, deflection of the nozzle hole plate produced at the time of applying a fuel pressure is suppressed, and moment produced at the weld part is reduced, making it possible to set the thickness of the nozzle hole plate smaller.
FIG. 4 shows distribution of stress produced in the weld part at the time of operating the fuel injection valve in comparison with that of the conventional valve. In the drawing, the axis of ordinates indicates weld depth in mm, and the axis of abscissas indicates developed pressure in Mpa. It is understood from this drawing that the larger the weld depth is the less the stress is.
Embodiment 2
Now referring to FIG. 5 , Embodiment 2 of the invention is described. In this Embodiment 2, the same construction as in the foregoing Embodiment 1 is employed except that configuration of a nozzle hole plate is different. More specifically, in the nozzle hole plate 81 of this Embodiment 2, a thickness T of the outer circumference thereof is formed to be larger than a thickness t of the central part in order to suppress the moment due to fuel pressure of the nozzle hole plate. A plurality of inclined jet holes 24 is formed on this nozzle hole plate 81 . Supposing that length of a jet hole 24 is L, diameter of the jet hole 24 is D, it has been acknowledged that atomization of fuel liquid injected through the mentioned jet holes 24 is desirably controlled by appropriately setting a ratio between L and D, i.e., L/D. In addition, it is preferable that the thickness T is set to be in the range of 1.0 to 1.5 mm and the thickness t is in the range of 0.4 to 0.7 mm.
Generally it is preferable that L is set to be smaller in the atomization carried out by deflection of the fuel flowing through inside the jet holes 24 . When L is smaller, the time of contact between fuel and air in the jet holes 24 is shorter, and an amount of air mixed with the fuel flow becomes less enabling to perform fuel injection of high purity. Accordingly, atomization characteristics of fuel are improved by thinning the central part where the jet holes 24 are located, while the outer circumferential part being thickened, thereby securing a mechanical strength with respect to welding and the like. As a result, this Embodiment 2 provides a more preferable fuel injection control valve.
Embodiment 3
Now, referring to FIG. 6 , Embodiment 3 of the invention is described. FIG. 6 is an enlarged view of an essential part of a tip of a valve member 3 of a fuel injection valve 1 and corresponds to FIG. 3 of the foregoing Embodiment 1. In this Embodiment 3, the same construction as in the foregoing Embodiment 1 is employed except that configuration of a gap 22 a is different. That is, in the foregoing Embodiment 1, a step portion 22 is formed on the end of the nozzle in order to provide an even gap g on the entire circumference between the nozzle hole plate 8 and the nozzle. On the other hand, in this Embodiment 3, a step portion 22 is formed on the valve seat 7 and nozzle hole plate 8 side in order to provide an even gap g. As a result of such construction, since it is not necessary to apply any machining for forming the gap to the nozzle 9 , a nozzle can be configured with high accuracy.
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A fuel injection valve device is capable of thinning a nozzle hole plate and improving fuel spray characteristics by a construction for reducing stress concentration that occurs at the weld part of the nozzle hole plate. The fuel injection valve device includes: a nozzle having a fuel passage inside and in which a valve seat is formed at an end; a needle valve for opening and closing the fuel passage by coming in contact with and separating from the valve seat; and an nozzle hole plate that is disposed at the tip of the nozzle and injects a fuel in the fuel passage at the time of opening the needle valve. The nozzle hole plate and the nozzle are fixed by welding in a state of forming an even gap between them.
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FIELD OF INVENTION
This invention relates to a device useful for sensing ammonia and nitrogen oxide(s) gases at room temperature.
The present invention particularly relates to a device which incorporates a sensor capable of sensing ammonia and nitrogen oxide(s) gases at room temperature.
BACKGROUND OF INVENTION
The extensive pollution problems in modem industrialized societies are adversly affecting our health and environment. Ever increasing industrialisation and number of automobiles make it absolutely necessary to constantly monitor and control air pollution in the environment. In many industries gases have become increasingly important as raw materials. Therefore, it has become very important to develop highly sensitive gas sensors and systems to prevent accidents and air pollution due to gas leakage. As a result, new and powerful research areas have emerged in our battle for awareness and environmental and health monitoring. The research and development of solid state gas sensor is one such area. Such sensors should allow continuous monitoring of the concentration of particular gases in the environment in a quantitative and selective manner.
Solid state gas sensors use an appropriate material, either in bulk form or in thick or thin film form as gas sensing element. The working principle for gas detection of these sensors is based on change in i) work function; ii) resistance iii) dielectric constant and or iv) mass of the sensing element due to adsorption of a gas. The resultant change in any one of these properties is measured to determine the presence and percentage of the gas in the ambient. Most of conventional sensors employ bulk or thick films of a gas sensing material.
However, in recent sensors, thin films are used as modern thin film preparation techniques give better control on gas sensing properties of a material.
Hitherto known gas sensors based on thin films of materials are of three kinds. First, metal oxides such as SnO 2 , ZnO, Ga 2 O 3 etc. (Taguchi: UK Patent 1280809, Mosely: Sensors & Actuators, B 6, 1992). Second, catalytic metals like Pd and Pt (I. Lundstrom et. al: Appl. Phys. Letts. 26, 1975, Sh. Kaihatsu: JP 1213563 A) and third, a special class of organic materials such as Phthalozyanine, Polypyrol u. a. (P. M. Burr et.al: Thin-Solid Films, 151, 1987, M. Josowicz: "Organic semiconductors as chemical sensor materials", Habilitation Universitat der Bundeswehr Munchen). The working principle for gas detection of most of these sensors is based on change in work function of the thin films, due to adsorption of a gas which in turn produces electrical signal. This signal is measured for qualitative and quantitative detection of a particular gas under test in the ambient. However, for the first type of sensors i.e. metal oxide based gas sensors, energy is needed for chemo-physical reactions on the sensing layer. This is achieved by heating the sensitive layer. Therefore, operating temperature of metal oxides based sensors is few hundred degree celsius e.g. from 300° C. to 1000° C. Reference may be made to (i) UK Patent 1280809--A. Mandelis (ii) C. Christofides: A Series of monographs on Analytical Chemistry and its Applications, ed. J. D. Winefordner, Vol. 125, John Wiely & Sons, INC. N.Y. 1993, Chapters 1 to 3 & Refs. there in, and (iii) M. Fleischer et. al. Sensor & Actuators B 25-27, 1995. The sensitivity, selectivity and dynamic response of these metal-oxide based sensors are temperature dependent and this necessitates them to operate at elevated temperatures. To realize these sensors, a heater is provided to heat the sensing film. Generally a thin film heater is fabricated on the back side of the sensing film and electrical power is supplied to it to achieve the desired temperature. Additionally, a temperature sensor is also required to be incorporated with the gas sensor to control the power to regulate the temperature of the sensor. Therefore, a heater and a temperature sensor are integral components of a gas sensing system based on metal-oxide sensors. In this way, heating requirement of the sensor makes fabrication technology and design of the sensing system very complex. It also necessitates thermal isolation between the sensor and the measurement circuit. Further, sensitivity of these sensors is critically dependent on film structure and its preparation technique (Peschke, M. et.al, sensors & Actuators B1, 21, 1990, Peschke, Ph. D. Thesis, 1990, Universitat der Bundeswehr Munchen, A. Mendelis and C. Christofides: Ref. above). The high temperature requirement of these sensors precludes their applications to battery operating equipments. Although application of catalytic metals films like Pt and Pd in FET or CCFET (Capacitive controlled FET) gas sensors has demonstrated room temperature operation (I. Lundstrom et. al, Sensors & Actuators Al, 1981 and Gergintschew, Z., Kornetzky, P., Schipanski, D., Patentschrift DE 433875 At.) but such ammonia gas sensors suffer from a drawback of their cross-sensitivity to hydrogen and hydrocarbon based gases. In addition to poor selectivity, metal film sensors also exhibited ageing effects (K. Dohos et.al Sensors & Actuators 4, 1983). Thus, despite of possibility of room temperature operation, these sensors have not yet became popular due to selectivity problem. For some special applications, the organic materials films are highly sensitive and selective but life time of organic film sensors is limited. Additionally organic materials films are not compatible to micro-electronic fabrication technologies and therefore, are not suitable for large scale production. In brief, the gas sensors known to date either can operate at elevated temperatures or suffer from selectivity problem.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide a device useful for sensing ammonia and nitrogen oxide(s) gases at room temperature, which obviates the drawbacks of the hitherto known devices for gas sensing applications.
Another object is to provide a device useful for sensing ammonia and nitrogen oxide(s) NO x gases at room temperature which incorporates a sensor capable of sensing gases at room temperature.
Yet another object is to provide a device useful for sensing ammonia and nitrogen oxide(s) gases at room temperature which is capable of sensing NH 3 and NO x selectively.
Still another object is to provide a device useful for sensing ammonia and nitrogen oxide s) gases at room temperature which is not cross sensitive to hydrogen and hydrocarbon based gases. Another object is to provide a device useful for sensing ammonia and nitrogen oxide(s) gases at room temperature which give fast response to test gases even at room temperature i.e the response times are low at room temperature.
Yet another object is to provide a device useful for sensing ammonia and nitrogen oxide(s) gases at room temperature which has high sensitivity and selectivity at or around room temperature.
Through our sustained research efforts we have found the gas sensing properties of thin films of cuprates, which are commonly known as high temperature superconducting cuprates. We found that these materials are sensitive to ammonia and nitrogen oxide(s) gases at room temperature while their sensitivity to carbon monoxide, carbon-dioxide, hydrogen and hydrocarbon gases is negligibly low. The reaction times are in seconds. The device of the present invention relates to application of materials of cuprate-superconductor family as gas sensing element which can be operated at or around room temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1--A sensor device for detection of ammonia and nitrogen oxides.
FIG. 2--Detection of ammonia using metallic films of BSCCO materials on MgO/Strontium Oxide.
FIG. 3--Detection of nitrogen oxides using metallic films of BSCCO materials on MgO/Strontium Oxide.
In FIG. 1, of the drawings accompanying this specification a schematic of the device of the present invention is depicted. The device of the present invention consists of a perforated cap (1), a sensor holder (2), a sensor (3), a detection circuit (4) and a display and/or recording unit (5).
Accordingly, the present invention provides a device useful for sensing ammonia and nitrogen oxide(s) gases at room temperature, which comprises a sensor holder (2) having a sensor (3), consisting of a layer of material of cuprate family on a substrate, the sensor being provided with a perforated cap (1) resistant to gaseous exposure, the out-put of the said sensor being connected to a known detection circuit (4) coupled to a known display and/or recording unit (5).
In an embodiment of the present invention the sensor may be a layer of material of cuprate family selected from a thin film of metallic or semiconducting Y:Ba:Cu:O (YBCO) or Bi:Sr:Ca:Cu:O (BSCCO) on a substrate selected from magnesium oxide, strontium titnate, gold, silver, stainless steel etc. In another embodiment of the present invention, the sensing layers of the materials can be prepared by any technique known in thin film or microelectronic technologies. In yet another embodiment of the present invention, any compound of cuprate family materials can be used as a sensing layer. In yet another embodiment of the present invention, doping of foreign element/s in a cuprate compound can also be used to prepare sensing layer. In yet another embodiment of the present invention: a thin layer coating of ambient resistant material like gold on the cuprate film can also be used to prepare sensing layer of the sensor.
DETAILED DESCRIPTION OF THE INVENTION
The construction of the device of the present invention is shown in FIG. 1 of the drawings. It consists of a perforated cap (1), which is made of any material which is resistant to hazardous gases to which it is likely to be exposed. For example it can be made of stainless steel or teflon or a special quality plastic. Sensor holder (2) may be such as a standard header generally being used for packaging devices in semiconductor industries. Sensor (3) may be a field effect transistor (FET) or capacitive coupled field effect transistor (CCFET) to which the gas sensing layer is electrically connected. Output of the sensor is connected to any known detection circuit (4) capable of measuring it. The output of the detection circuit is fed to a display or recording unit (5) which contains suitable known circuit/s to display output proportional to the signal output of the sensor.
The working principle of gas sensing is based on change in work function of the sensitive layer due to gas adsorption on its surface. The gas sensitive layer is connected to the gate electrode of a measuring transistor (FET). Therefore, when the sensor is subjected to a gas, it enters into the housing through the holes in the cap and reaches onto the surface of the sensing layer. This gas reacts with the sensitive layer and changes its work function. Since the sensitive layer is electrically connected to the gate of the FET, corresponding change occurs in the gate voltage of the transistor. This change is measured by the detection circuit which further activates the recording or display unit. As change in work function of the sensitive layer is directly proportional to the percentage of the reactive gas present in the gas sample under test, the change in gate voltage and hence output of the detection circuit is a measure of the amount of the reactive gas present in the gas sample.
Gas sensitive films of the cuprates of the present invention can be prepared by sputtering, evaporation, chemical vapor deposition, spin-on, screening or any other film preparation technique known and used in microelectronic technology. Also for preparation of films, any approach known in preparation of commonly known high temperature superconductor can be used. For example a composite material having composition of a cuprate compound and/or separate chemical compounds containing desired elements can also be used to prepare these films. Film deposition can be done on a hot substrate as being done for preparation of in-situ superconducting films or room temperature deposition followed by heating (ex-situ) can also be used. These films may also be semiconducting or metallic in behavior in normal temperature range and can also be covered by a thin protecting film of metal such as gold etc. All these modifications do not change effectively the gas sensing properties of the films of these materials. In brief, the gas sensing properties of the cuprates which have been used as a sensing layer in the present invention are not very critical to composition of the film material or the technique which has been used to prepare the films. The gas sensing property of thin films of cuprates used as a sensing layer in the present invention is based on change in work function of the film material when it is exposed to a gas. The semiconducting films of cuprates are sensitive to ammonia only whereas the metallic films of these materials are sensitive to ammonia and NO x both As these metallic layers give signal in opposite direction when exposed to NH 3 and NO x respectively, the same sensor can be used to detect ammonia and NO x selectively. Further, their cross-sensitivity to H 2 , CO, CO 2 and hydrocarbon gases is negligible where as conventional metal or metal oxide sensors are highly cross-sensitive. Therefore, a sensor employing metallic films of cuprates is also highly selective. Morever, these films also exhibit conductivity modulation to high concentrations of the gases and thus can be used to realize conductivity type sensors also. The work function based sensors of these materials shows high sensitivity, even for a few ppm of NH 3 in the temperature range of 0° C. to 40° C. The reaction times of the present materials are in seconds while in conventional sensors the response times are several minutes. To improve sensor signal and response times, the metal/metal-oxide sensors are operated at high temperature thus conventional sensors are not suitable for room temperature applications. Therefore, the sensors of the present invention consume low power and suitable for battery operated device/system. Unlike conventional sensors the gas sensing properties of device of the present invention, is not critically or strongly dependent on the technique used for preparation of the sensing films. The room temperature gas sensing capability of the layers of the materials used in the present invention is a novelty.
The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of the present invention:
EXAMPLE 1
The device of the present invention was used in a configuration of Capacitively Controlled Field Effect Transistor structure (CCFET). In this structure, sensitive layer forms one electrode of a capacitor and the second electrode of the capacitor is kept floating which is connected to gate of a FET. Due to gas reaction on the sensitive electrode, equal and opposite potential on floating electrode is generated which in turn changes gate voltage of the FET. Change in gate voltage of the FET is recorded as signal produced due to reaction of a gas with the YBCO film. The measured voltage is non-amplified sensor signal and thus it is a direct measure of sensitivity of the film, to the gas to which it is exposed. Different concentrations of test gas in synthetic air is used to measure the sensor signal. We observed that the semiconducting film on silicon-dioxide substrate is highly and selectively sensitive to only ammonia. As seen in FIG. 2, of the drawings accompanying this specification, a signal of more than 10 mV is recorded for 5 ppm of ammonia in air. Typical rise time of 24 seconds and full time of about 250 seconds have been estimated from response of the sensor at 24° C.
EXAMPLE 2
The metallic films of BSCCO materials on Mgo/Strontium Oxide are used as a sensing film in the device. For ammonia, response like FIG. 2, of the drawings is recorded. However, for NO x signal of opposite polarity is observed. FIG. 3, of the drawings shows a typical response of the device when it is exposed to NO x . Response to NO x is also fast and approximately response times like ammonia are obtained.
EXAMPLE 3
The measurement with our device using YBCO sensing films on MgO/Strontium Oxide, which are metallic in character are also similar to that shown in FIGS. 2 & 3 of the drawings. Thus the response of the device with metallic YBCO films is same as that of the device with BSCCO sensing films. Therefore, the device of the present invention can be used to detect NH 3 and NO x selectively.
EXAMPLE 4
The measurements at different temperatures(5° C., 18° C., 22° C. and 35° C.) illustrate that the response times are not much influenced by operating temperature while sensor signal is reduced to 40% when temperature is increased from 18° C. to 35° C. However, it is decreased only by 5% if the temperature is reduced to 5° C. These results evince that the sensitivity of YBCO to ammonia is optimal in the temperature range of 15° C. to 25° C.
EXAMPLE 5
The measurements with gases like hydrogen, propane, methane, ethane, carbon mono-oxide, carbon dioxide and nitrous oxide gases indicate that either the sensor signal is negligibly low or it does not behave like a sensor.
EXAMPLE 6
We have coated the cuprates films with a thin layer of gold and investigated the sensor response to gases. We found that sensing behaviour of the gold coated film is same as that of the bare films. This evince that cuprates film can be coated with a thin protecting layer without affecting the sensor performance.
From example 1, we observe that semiconducting cuprates are highly sensitive to ammonia only. Examples 2 and 3 evince that metallic cuprates are sensitive to both ammonia and NO x . Since out put signal voltage of the sensor is of opposite polarity in these two cases the same sensor can be used selectively to detect NH 3 or NO x at room temperature. The example 4, suggests that the device of the present invention is useful for sensing gases at and around room temperature The example 5, demonstrates that the present device does not show cross-sensitivity to hydrogen or hydrocarbon gases thus it is suitable for sensing ammonia and NO x selectively. Further, the example 6, suggests that gold coated sensing films are also suitable for the sensing device.
The main advantages of the device of the present invention are:
1. The device is capable of sensing gases at or about room temperature.
2. A film of any compound of family of materials known as cuprates particularly metallic or semiconducting cuprates can be used as a sensing layer to construct sensor of the device which can be operated at or around room temperature.
3. The device is useful for sensing ammonia and NO x with high sensitivity and selectivity without cross-sensitivity to hydrogen and hydrocarbon based gases.
4. The device is capable of sensing both ammonia and NO x selectively as sensor output signal is of opposite polarity in detection of these two gases.
5. Gas sensing capability of the device at room temperature eliminates requirement of heater and temperature sensor which are otherwise essential in a conventional sensor.
6. The power consumption required to heat the sensing layer is completely eliminated in the present device.
7. Battery operation is possible in the present case.
8. The capability of room temperature gas sensing makes it viable to fabricate sensing layer on the same semiconductor chip on which detection and measurement circuits are fabricated.
9. The film preparation techniques to prepare sensing layers of cuprates used in the present device are compatible to micro electronic technology.
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A device for sensing ammonia (NH 3 ) and nitrogen oxide (NO x ) gases comprising: a sensor for detecting said ammonia and said nitrogen oxide gases, said sensor including a substrate and a layer consisting of cuprate material for detection of said ammonia and said nitrogen oxide gases, wherein said layer of cuprate material is selected from the group consisting of Y:Ba:Cu:O (YBCO) and Bi:Sr:Ca:Cu:O (BSCCO); a sensor holder for supporting said sensor; a perforated cap positioned over said sensor, said perforated cap having openings for passage of said ammonia and said nitrogen oxide gases to said sensor; a detection circuit communicating with said sensor for measuring output from said sensor; and a display or recording device connected to said detection circuit for displaying or recording a concentration of said ammonia and said nitrogen oxide gases based on the output from said sensor.
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This is a continuation-in-part of application Ser. No. 947,709, filed 12/30/86, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a permanent magnetic alloy comprising precious metals and more particularly to a magnetic alloy mainly composed of gold for use in magnetic personal ornaments.
2. Description of the Related Art
It has been known for a long time that magnetism has an effect upon the human body, and since an effect of magnetism for medical purposes was recently confirmed by public agencies, many kinds of magnetic health implements have been commercialized.
In the field of the magnetic health implements, there are objects called magnetic personal ornaments such as magnetic necklaces, magnetic bracelets and magnetic rings. These magnetic ornaments are that small ferrite magnet or rare-earth magnet pieces are enclosed in metallic receptacles and connected in the shape of a chain. Therefore, they are valued as health implements and accessories, but hardly valued as jewelry. In the circumstances, a precious metal magnet is ardently desired which is mainly composed of gold, platinum, silver or the like and capable of constituting a magnetic alloy by itself.
As a precious metal magnet, a platinum (Pt) - cobalt (Co) alloy magnet is known. This is an order-disorder transition type of alloy containing 77% Pt and exhibits very strong magnetic performance (hereinafter the term "percent, %" means a weight percent). However, an alloy containing less than 85% Pt is not publicly approved as a platinum alloy and it is thought that it has little value as jewelry.
On the other hand, as a magnetic alloy containing gold (Au), an alloy comprising Au, nickel (Ni) and iron (Fe) (Japanese unexamined patent application 57-5833) and an alloy comprising Pt, Au and Fe (U.S. Pat. No. 3,591,373) are known.
The former (hereinafter referred to as conventional alloy ANF) is an alloy containing 75% Au (equivalent to 18 Karat), but its coercive force is about 500 oersteds. A general chain-shaped ornament has a disadvantageous shape for magnetizing, and the coercive force of around 500 oersteds is not enough to provide a sufficient remanence. In order to enable the magnetic ornament to produce a medical effect, it is thought necessary for the ornament to have a remanence of at least 500 gausses (G). In order to obtain this value by a general chain-shaped ornament, as will be explained later, a coercive force of at least 1300 to 1500 oersteds (Oe) is required.
On the other hand, the latter alloy is not approved as a gold alloy, because it is mainly composed of Pt and contains less than 50% Au. Unless the alloy contains at least 50% gold (12 Karat), it would have no such commercial value that it can be called gold jewelry.
SUMMARY OF THE INVENTION
Therefore, one of the objects of the invention is to develop a magnetic alloy containing 50% or more gold, having an ornamental shape and attaining a remanence of 500 G or more.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a ternary composition diagram showing composition ranges of alloys of the invention;
FIG. 2 is a diagram showing demagnetizing curves of alloys of the invention in comparison with the conventional alloy; and
FIG. 3 is a ternary composition diagram showing a distribution of remanences of the embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the above object, according to the invention, the magnetic properties of the alloys mainly composed of gold (Au), platinum (Pt) and cobalt (Co) and also alloys in which iron (Fe), nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), or the like are added to the above alloys were examined, and ranges of composition having excellent magnetic performance were determined.
A Pt-Co alloy is typical of order-disorder transition type permanent magnetic alloys, and an alloy having a 1:1 atomic ratio composition (50 atomic percent Pt, that is, 77 weight % Pt) exhibits an extremely high coercive force in a process of transforming to the ordered state by heat treatment.
In this connection, when Au is added to this Pt-Co alloy to produce an Au-Pt-Co ternary alloy, a two-phase coexistence condition having α 1 phase mainly composed of Au and α 2 phase mainly composed of Pt-Co is obtained.
In this case, in the α 1 phase mainly composed of Au, small amounts of Pt and Co are dissolved, while in the α 2 phase mainly composed of Pt-Co, Au is hardly dissolved. Therefore, the magnetic properties of the Pt-Co alloy appear in proportion to the relative amount of the α 2 phase.
The present invention has been made from the above viewpoint and will now be described with reference to the embodiments.
A total of 30 kinds of alloys comprised of 50 to 75% Au, 12 to 42% Pt and 2 to 15% Co and alloys in which Fe, Ni, Cu, Pd and Ag are added to the above alloys were prepared by an induction melting method, then, made into wire by plastic deformation and cut into test pieces for measurement.
When these alloys were cooled rapidly by plunging into water from a temperature of 900° C. which exceeds an order-disorder transition temperature, they were in a disordered state. This treatment is called a disordering. In this disordered state, these alloys permit plastic deformation such as rolling and wiredrawing.
Table 1 lists the compositions of these alloys.
Table 2 lists the maximum values of the magnetic properties varying with aging time when after the disordering, these alloys were heated to a temperature below the transition temperature for transforming to the ordered state (this treatment is called an aging).
FIG. 2 shows demagnetizing curves exhibiting the magnetic properties obtained in alloys Nos. 3, 12 and 25 of the embodiment of the invention and also shows the properties of the above-mentioned conventional alloy (ANF) for comparison. Alloys Nos. 3, 12 and 25 are gold alloys equivalent to 12 K (Karat), 14 K and 18 K, respectively, and it is evident that with increase in gold content, the magnetization and the coercive force are lowered.
As mentioned before, the magnetic personal ornament is generally formed into a plain chain shape and magnetized in the direction of its thickness for use. As a result, it is used in an extremely disadvantageous condition where its permeance coefficient, P (a value of the condition of use of the magnet) is low, and its permeance coefficient is around 0.4.
In FIG. 2, a line of P=0.4 is plotted. The intersection of this line with each of the demagnetizing curves is called a work point magnetization and serves as the standard of a remanence (Bd) actually obtained in the shape of the ornament.
As shown in FIG. 2, the 12 K alloy has a remanence (Bd 0.4) of 940 G, the 14 K alloy, 800 G, and 18 K alloy, 520 G. In contrast, it is found that the above-mentioned conventional alloy (ANF) has a remanence of only about 200 G. Furthermore, in order to obtain a remanence of 500 G or more in a plain ornament shape having a permeance coefficient of P≃0.4, it can be read from FIG. 2 that a coercive force of at least 1.3 to 1.5 kilo-oersteds (KOe) is necessary.
Table 2 shows a saturation magnetization, 4πIs (KG); residual magnetization, Br (KG); coercive force, Hc (KOe); maximum energy product, (BH) max (MGOe); and remanence, Bd 0.4 (G) at a permeance coefficient of P=0.4, in the aged condition in which the maximum Bd 0.4 value was obtained for each alloy.
FIG. 3 is a ternary composition diagram showing each remanence (Bd 0.4) obtained in Au-Pt-Co ternary alloys of the embodiment of the present invention.
Reason for Limiting Composition
As recognized from Tables 1 and 2 and FIGS. 2 and 3, it is evident that the higher performance is obtained as the Au content decreases. However, the object of the invention is to provide a composition of Au exceeding 50%, and the lower limit of Au is set to 50% (12 K).
Also, when Au is contained 75% (18 K), the desired remanence is kept, but if the Au content is increased to 20 K and 22 K, it is assumed that the required remanence is not obtainable any more. As a result, the upper limit of Au is set to 75% (18 K).
In the 12 Kalloy, when the Pt content exceeds 40%, the remanence suffers rapid deterioration. On the other hand, in the 18 K alloy, when the Pt content is less than 16%, the required remanence is not obtainable. Therefore, the composition range of Pt in the Au-Pt-Co ternary alloy is set to 16 to 40%.
On the other hand, as shown in alloys Nos. 29 and 30, when part of Pt is substituted with Pd, the desired remanence is obtained until the Pt content is 12%.
Therefore, in an alloy base consisting of four or more different elements, the composition range of Pt is set to 12 to 40%.
In the 12 Kalloy, the object is attained until the Co content is 15%, but it is thought that exceeding this value is useless. On the other hand, in the 18 K alloy, when the Co content is less than 3%, the performance suffers rapid deterioration. Therefore, the composition range of Co is set to 3 to 15%.
The range of composition limit for Au-Pt-Co ternary alloys of the present invention is shown in a composition diagram of FIG. 1.
As shown in alloys Nos. 5, 15 and 28, when part of Co is substituted with Fe, the magnetization increases and the remanence is enhanced. On the other hand, as shown in alloy No. 6, when part of Co is substituted with Ni, the remanence is slightly deteriorated. In this case, however, it has an advantage in that a water quenching is not required for disordering, so that the disordered state can be obtained by air cooling.
As shown in alloys Nos. 7, 8 and 16, when Cu and Ag are added to an Au-Pt-Co alloy, a 12 Kalloy exhibits the character of a 14 K alloy and a 14 K alloy exhibits the character of a 16 K alloy. Thus, the contents of Au and Pt can be decreased to save the material cost.
Furthermore, as shown in alloys Nos. 9, 15, 29 and 30, when part of Pt is substituted with Pd, the Pt content can be extremely decreased without deteriorating the remanence so much, and this is very advantageous from the viewpoint of the material cost.
These elements can be added singly or in combination, but it is thought useless that a total of additive amount exceeds the range of the embodiment, and therefore, they are limited to 3 to 12%.
As mentioned above, the alloys of the invention contain 50% or more gold which can be designated as gold alloys. Since each has a high coercive force, a required remanence can be maintained even in a plain-shaped ornament, and it is particularly useful for material for high-class magnetic personal ornaments, that is, magnetic jewelry.
TABLE 1______________________________________Alloy composition (weight %)No. Karat Au Pt Co Other elements______________________________________1 12K 50.0 42 8 none2 12K 50.0 40 10 none3 12K 50.0 38 12 none4 12K 50.0 35 15 none5 12K 50.0 38 8 Fe 46 12K 50.0 38 9 Ni 37 12K 50.0 33 10 Ag 78 12K 50.0 33 10 Cu 79 12K 50.0 30 10 Pd 1010 -- 55.0 35 10 none11 14K 58.3 33.7 8 none12 14K 58.3 31.7 10 none13 14K 58.3 28.7 13 none14 14K 58.3 26.7 15 none15 14K 58.3 23 6.7 Pd 7, Fe 516 14K 58.3 22.7 7 Cu 1217 -- 60 35 5 none18 -- 60 31 9 none19 -- 65 27 8 none20 16K 66.7 27.3 6 none21 16K 66.7 23.3 10 none22 -- 70 23 7 none23 18K 75 23 2 none24 18K 75 21 4 none25 18K 75 19 6 none26 18K 75 17 8 none27 18K 75 15 10 none28 18K 75 18 4 Fe 329 18K 75 14 4 Pd 4, Fe 330 18K 75 12 5 Pd 8______________________________________
TABLE 2______________________________________Magnetic properties Remanence 4π Is Br Hc (BH)max Bd(0.4)No. (KG) (KG) (KOe) (MGOe) (G)______________________________________1 4.0 2.0 0.8 0.5 3002 4.0 3.2 2.3 2.3 7703 4.1 3.6 2.8 3.0 9404 5.4 4.5 1.5 2.2 5705 4.5 4.0 2.9 3.7 9706 3.3 3.0 2.7 2.3 8407 3.1 2.8 2.4 2.0 7508 3.2 2.9 2.3 2.0 7509 3.4 3.1 2.4 2.1 78010 3.5 3.3 2.7 2.6 87011 4.1 2.0 0.8 0.5 28012 3.4 3.1 2.5 2.2 80013 5.0 2.9 1.6 1.4 56014 6.4 1.9 0.4 0.2 16015 3.4 3.2 2.7 2.7 86016 2.6 2.3 1.9 1.3 50017 3.1 1.5 0.5 0.3 20018 3.2 3.0 2.8 2.2 83019 3.1 2.7 2.2 1.6 67020 2.9 2.1 1.0 0.6 35021 4.1 3.1 1.1 1.1 41022 2.7 2.4 2.1 1.3 63023 1.0 0.3 0.1 0.01 4024 1.6 1.3 1.0 0.4 32025 2.3 2.1 1.6 0.9 52026 3.1 2.3 1.1 0.7 38027 4.5 1.4 0.1 0.06 4028 2.7 2.4 1.5 1.1 51029 2.5 2.3 2.0 1.3 62030 2.3 1.9 1.6 0.8 500______________________________________
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A permanent magnetic alloy mainly composed of gold for making magnetic personal ornaments comprises 50 to 75 weight % gold, 12 to 40 weight % palladium and 3 to 15 weight % cobalt. The alloy is gold or white gold in color and can be plastically deformed to a desired shape. The 12, 14 and 18 Karat gold alloys have maximum energy products of 3.0, 2.2 and 0.9 MGOe, respectively.
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The government has rights to this invention based on research support in the form of Grant N. AID-DPE-0453-C-00-2002-00 from the Department of State, Agency for International Development.
This is a continuation of application Ser. No. 649,903, filed Sept. 12, 1984.
BACKGROUND OF THE INVENTION
The present invention relates to polypeptide antigens suitable for providing protective immunity against malaria by incorporation into a vaccine. These antigens have amino acid sequences corresponding to segments of the amino acid sequence of the circumsporozoite protein that lie outside the bounds of the tandemly repeated domain of such protein. The antigens of the present invention can be used to elicit formation of antibodies, which recognize sporozoites not only of the same species of plasmodium from which these antigens were derived, but of other species as well.
The present application incorporates by reference the entire disclosures of:
(a) U.S. Pat. No. 4,466,917 of Nussenzweig, R., et al., issued on Aug. 21, 1984;
(b) assignee's copending U.S. patent application No. 99,652 filed Sept. 21, 1987 as a 37 CFR §1.62 continuation of application Ser. No. 574,553 of Ellis, J. et al., filed on Jan. 27, 1984 and entitled Protective Peptide Antigen; and
(c) assignee's copending U.S. patent application No. 77,006 filed July 21, 1987 as a 37 CFR §1.62 continuation of application Ser. No. 633,147 of Ellis, J. et al., filed on July 23, 1984 and entitled Protective Peptide Antigen Corresponding to Plasmodium Falciparum Circumsporozoite Protein.
In most instances, malaria infections are initiated by the introduction of sporozoites (highly immunogenic forms of the malaria parasite) into the bloodstream of a host through the bite of an infected mosquito. The immunogenicity of sporozoites resides largely, if not exclusively, in a single antigen, the circumsporozoite (CS) protein (described in detail by F. Zavala, A. H. Cochrane, E. H. Nardin, R. S. Nussenzweig and V. Nussenzweig in an article in J. Exp. Med. 157: 1947 (1983). G. N. Godson, et al., Nature 305: 29 (1983) reported that the immunogenicity of the CS protein is restricted almost entirely to a single epitope which is identically or quasi-identically repeated several times in tandem. See also V. Enea, et al. Proc. Nat'l Acad. Sci. (accepted for publication, 1984).
Circumsporozoite proteins (CS proteins) are members of a family of polypeptides comprising the surface membranes of mosquito salivary gland sporozoites of mammalian malaria parasites of the genus plasmodium. The strong immunogenic properties of sporozoites are associated mainly with the CS protein. This protein, specific for the sporozoite stage, has an immunodominant region of repetitive epitopes. The repeated sequence from N to C terminus of the CS protein for P. knowlesi is Gln-Ala-Gln-Gly-Asp-Gly-Ala-Asn-Gly-Gln-Pro (also designated as QAQGDGANGQP) and the repeated tetrapeptide sequence of the CS protein for P. falciparum is Asn-Ala-Asn-Pro (also designated as NANP). Synthetic peptides consisting of multiples or analogs of the repeated amino acid sequences have been shown to be antigenic and are useful in the development of a malaria vaccine. Unfortunately, however, peptides derived from the immunodominant region of the CS protein display very little homology among themselves and only species-specific antigenicity.
Due to the immunodominance of the repetitive epitopes of the CS protein, it had not heretofore been possible to determine if other segments of the CS protein, which are not within the repetitive domain sequence, can induce antibodies affecting the viability of the parasite. Clearly, immunogenicity itself does not establish the utility of peptides having the sequence of such non-repeating segments as protective antigens against sporozoites, since such segments would need to be on an exposed surface of the CS molecule to allow recognition by antibodies.
OBJECTS OF THE INVENTION
It is an object of this invention to identify regions of the circumsporozoite surface proteins of a member of the genus plasmodium, other than the region containing the repetitive epitope, that contain other, non-repetitive epitopes for such protein.
Another object of this invention is to identify the non-repetitive epitopes of the CS protein, as a prerequisite for the development of an anti-malaria vaccine.
Yet another object of this invention is to identify and synthesize peptides (corresponding to the non-repetitive epitopes of the CS protein) that can elicit formation of antibodies in mammals which can in turn recognize the CS protein, in particular, the CS protein on the surface of sporozoites.
A further object of this invention is to identify and synthesize peptides capable of eliciting formation of antibodies that recognize the CS protein of more than one species of the genus plasmodium.
A further object of this invention is to identify such peptides as a prerequisite for the development of a synthetic malaria vaccine.
A still further object of this invention is to develop an immunogenic element for use in a malaria vaccine for administration to mammals.
SUMMARY OF THE INVENTION
This invention is directed to a peptide comprising an amino acid sequence corresponding to an epitope of a circumsporozoite surface protein of a member of the genus plasmodium, other than the repetitive immunodominant epitope of such protein. The peptide is capable of eliciting formation of antibodies in a host that recognize the circumsporozoite surface protein.
The peptides of the present invention are recognized by, and elicit formation of, antibodies that bind to the CS proteins of the malarial species from which they were derived and also to the CS proteins of other malarial species. This is so because segments of the sequence of CS proteins outside the immunodominant regiion are extensively homologous. Once one such peptide has been identified, the amino acid (and nucleotide) sequence of other peptides having the same properties can be readily identified by comparing the sequences of CS proteins of different species. These peptides are useful elements in the development of a synthetic malaria vaccine. They can be made by synthetic method, of they can form part of genetically engineered constructs.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic representation of the sequence of the intracellular precursor of P. knowlesi CS protein.
FIG. 2 is an autoradiograph of Western blotting (immunoblotting) of antibodies to synthetic peptides N2 and C2 of the present invention with P. berghei sporozoite extracts.
FIG. 3 is a schematic representation of segments of the P. knowlesi and P. falciparum CS protein outside the immunodominant epitope of these proteins. These segments have been aligned to achieve the highest degree of homology.
DETAILED DESCRIPTION OF THE INVENTION
The primary structure of the CS protein for P. knowlesi and P. falciparum was first deduced from the nucleotide sequences of these proteins (Godson, G. N., et al., Nature, 305: 29 (September 1983) and Dame, J. B., et al., Science, 225: 593 (1984)). A schematic representation of the intracellular precursor of P. knowlesi CS protein is shown in FIG. 1. Two regions of this protein contain a large number of charged residues (these regions ae labeled "charged" in FIG. 1) and may contain an alpha-helical structure. One charged region at the amino terminal (N-terminus) end of the protein flanks the domain (segment) containing the tandem amino acid repeats. The other charged region, close to the C-terminus, is flanked on each side by a pair of cysteine residues.
Peptides having an amino acid sequence corresponding to these charged regions have been synthesized. The polar character of the charged regions indictes that they should be exposed on the surface of the CS molecule. Certain of these peptides are recognized by polyclonal antibodies raised against sporozoites (Vergara, et al., Mol. & Bioch. Parasitol., 1984, in press). Polyclonal antibodies raised against these peptides also recognize and bind authentic P. knowlesi CS protein on the surface of sporozoites, demonstrating the immunogenic properties of such peptides. Antibodies to N2 and C2 peptides (FIG. 1), react on the surface of sporozoites of P. falciparum, P. vivax, P. malariae, P. brasilianum, P. bergei, and P. cynomolgi.
The data demonstrate that the immogenic peptides correspond (or are closely related) to the corresponding exposed exterior segments of the CS molecule of most or all species of sporozoits from malaria parasites, and are not excised during intracellular processing of the CS molecule.
Comparison of the N2 and C2 peptides with the corresponding region of P. falciparum CS protein, as published in Dame et al, supra, shows a high degree of homology. Significantly, anti-sera raised against these peptides recognize the sporozoites of other species of the plasmodium genus as well.
The partial neutralization by a rabbit antiserum to one of these peptides (N 2 in FIG. 1) of the infectivity of sporozoites from an heterologous species, P. berghei, demonstrates the presence of a related structure in corresponding regions of CS proteins of this species and that the N2 region is highly conserved in evolution.
Previous evidence shows that antibodies to the repetitive domain of CS protein neutralize infectivity of sporozoites of the species containing that CS protein and suggests that synthetic peptides incorporating the epitope of this repetitive domain could be used in species-specific vaccine preparations. The present invention leads to the conclusion that synthetic polypeptides, or conjugates and/or genetic engineering constructs incorporating the sequence of other peptides, which represent conserved (not species-specific) and exposed regions of the CS molecule, will protect a host against infection by any of several different species of malaria parasites.
EXAMPLE 1: ANTI-SPOROZOITE POLYCLONAL ANTIBODIES
Sporozoites of P. knowlesi were obtained from mosquito salivary glands from 10 to 18 days after an infective blood meal, according to the method of Vandenberg, J. P. et al., Further Studies on the Plasmodium Berghei--Anopheles Stephensi--Rodent System of Mammalian Parasite, J. Parasitol. 54: 1009-1016 (1968). These sporozoites were used to elicit polyclonal antibodies in a rabbit by ten intravenous injections of 10 6 -10 7 live sporozoites over a period of three months.
EXAMPLE 2: PEPTIDE SYNTHESIS
Several peptides were chosen for synthesis and immunization. The first was a tetraicosapeptide consisting of a dimer of the repetitive dodecapeptide of the P. knowlesi CS protein. This dodecapeptide is designated by the dotted boxes in FIG. 1. The synthesized tetraicosapeptide will be termed "2x repeat". The 2x repeat is a dimer of the amino acid sequence (from N to C terminal) Gln-Ala-Gln-Gly-Asp-Gly-Ala-Asn-Ala-Gly-Gln-Pro.
Two other peptides correspond to segments of the CS protein found in the domains labelled "charged" in FIG. 1. The first one, designated N 2 , corresponds to amino acids 86-99 in FIG. 1 and has the amino acid sequence Pro-Lys-Lys-Pro Asn-Glu-Asn-Lys-Leu-Lys-Gln-Pro-Asn-Glu also designated as PKKPNENKLKQPNE). The second one, designated C 2 , corresponds to amino acids 312-331 of the CS protein and has the amino acid sequence Arg-Arg-Lys-Ala-His-Ala-Gly-Asn-Lys-Lys-Ala-Glu-Asp-Leu-Thr-Met-Asp-Asp-Leu-Glu (also designated as RRKAHAGNKKAEDLTMDDLE).
Finally, two additional peptides were synthesized, termed C 1 and "charged". The sequence of C 1 was taken from the region immediately adjacent to the repeats towards the C terminal. Its overall amino acid composition resembles that of the repeats. The "charged" peptide corresponds to the sequence immediately following N 2 towards the N terminal within the charged region. The sequence of C 1 is Gly-Lys-Gly-Ala-Gln-Lys-Asn-Gly-Glu-Asn-Gly-Gly-Ala-Pro-Ala-Gly-Gly-Gly-Asn-Arg-Gly-Gln-Arg (also designated as GKGAQKNGENGGAPAGGNRGQR). The sequence of "charged" is Lys-Pro-Glu-Glu-Glu-Lys-Glu-Lys-Gly-Lys-Glu-Lys-Lys-Lys-Glu-Lys-Asp-Ala-Gly-Glu-Lys-Pro-Lys-Glu-Gly (also designated as KPEEEKEKGKEKKKEKDAGEKPKEG).
All peptides were synthesized on a Vega Model 250C automated synthesizer (Vega Bio-Chemicals, Inc., Tuscon, Ariz.) controlled by a Motorola computer with a program based on that of Merrified, R. B., Fed. Proc. 21: 412 (1962); J. Am. Chem. Soc. 85: 2149 (1963).
The synthesis of the dodecapeptide (1× repeat), set forth below, is typical of all peptide synthesis. Three grams of benzhydrylamine resin were suspended and washed three times with methylene chloride (CH 2 Cl 2 ), three times with ethanol, and three more times with methylene chloride after placement in the synthesizer. After a total wash of 2 minutes, the resin was treated with 50% trifluoroacetic acid containing 10% anisole in CH 2 Cl 2 for 30 min., washed ten times with CH 2 Cl 2 , and neutralized by washing twice with 10% diisopropylethylamine in methylene chloride. The first BOC amino acid was coupled for one hour to the resin using 3-fold molar excess of dicyclohexyl carbodiimide, in the presence of a 3 molar excess of hydroxybenzotriazole in methylene chloride. Additional aliquots, one of hydroxybenzotriazole and one of diisopropylethylamine, were added at a 3-fold molar excess to BOC-amino acid for an additional hour. The resin was then washed in methylene chloride (3×), absolute ethanol (3×) and methylene chloride (3×), and an aliquot of the mixture was tested using the Kaiser ninhydrin procedure (Kaiser, E. et al., Analyt. Biochem. 34: 595 (1970). The resulting peptide was BOC-Gln(NPE)-Ala-Gln(NPE)-Gly-Asp(OBZ)-Gly-Ala-Asn(NPE)-Ala-Gly-Gln(NPE)-Pro-Co-BHA. The protected peptide resin was removed and saved for HF cleavage.
Cleavage was performed in a Penninsula HF apparatus (Penninsula, Laboratory, San Carlos, Calif.) in the presence of anisole (1.2 ml/mg resin) and methylethyl sulfide (1 ml/mg) at 0° C. for one hour, after which the mixture was thoroughly dried under high vacuum. The mixture was then washed with cold anhydrous ether, extracted with alternate washes of water and glacial acetic acid and lyophilized.
The crude peptides (200 mg aliquots) were desalted by gel filtration on a Sephadex G-25 column (120×2.0 cm) that had been equilibrated with 0.1NH 4 HCO 3 , pH 8.0. The column effluent was monitored by UV absorbance at 254 and 206 nm with an LKB UV-Cord III monitor. The collected peptides were then characterized.
EXAMPLE 3: PURIFICATION OF ANTIBODIES CAPABLE OF REACTING WITH SPECIFIC SYNTHETIC PEPTIDES
Polyclonal antibodies recognizing the peptides were isolated from the anti-sporozoite rabbit antisera prepared in Example 1. The peptides were coupled to activated Sepharose-4B beads (Pharmacia Fine Chemical Company, Piscataway, N.J.) according to the manufacturer's instructions. The beads were subsequently treated for one hour with 0.005M glutaraldehyde in 0.25M NaHCO 3 , pH 8.8. The washed beads were incubated with 1M ethanolamine, pH 9.0, for one hour, washed again in and resuspended in phosphate-buffered saline (PBS), pH 7.4.
To remove any non-specific binding substances, the anti-knowlesi antiserum was first adsorbed with beads conjugated to a non-relevant peptide. For example, to purify anti-C 2 antibodies, a sample of antiserum was sequentially adsorbed with N2-bearing beads, then with beads bearing peptides corresponding to other segments of the charged regions, and, finally with repeat-bearing beads. The supernatant resulting from the last adsorption was then incubated for several hours at room temperature with beads containing the peptide of interest. After washing repeatedly with PBS, the bound antibodies were eluted from the beads by treatment with 3M potassium thiocyanate. The eluate was immediately filtered through a small Sephadex G-25 column to remove small molecules. These purified antibodies were used to assay the synthetic peptides.
EXAMPLE 4: IMMUNORADIOMETRIC ASSAY
Synthetic peptides N 2 , C 2 "charged" (corresponding to amino acids 99-86 of the P. knowlesi CS protein), C1 (corresponding to amino acids 267-245) and "2× repeat" were prepared in accordance with the method of Example 2. The peptides were separately diluted to 20 micrograms/ml in 0.1M NaHCO 3 , pH 9.6. Fifty microliters of the solution were delivered to wells of polyvinyl chloride flexible microtiter plates (Dynatech Laboratories, Inc., Alexandria, Va.). After incubation overnight at 4° C., the wells were washed three tims with buffer containing Tween 20 (Biorad Laboratories, Richmond, Calif.), treated with 1% bovine serum albumin (BSA) in PBS for two hours at 4° C. and washed. Subsequently, 25 microliters of serial dilutions of the appropriate rabbit anti-sporozoite antiserum (from Example 3), were delivered to the wells, and the plate was incubated for 2 hours at 4° C. After washing, the well were incubated for 2 hours with 5×10 4 cpm in 30 microliters of 125 I-labelled affinity-purified goat anti-rabbit IgG diluted in PBS containing 1% BSA. The wells were washed, cut and counted. As negative controls, peptide-coated wells were incubated with normal rabbit serum and treated as above. The results show that the rabbit anti-sporozoite antiserum contained antibodies directed against the 2× repeat and the N2 and C2 peptides (the counts obtained in control wells incubated with dilutions of normal rabbit serum are subtracted from the counts obtained in experimental wells). The results show that the antiserum recognizes four peptides, N2, C2, "charged" and "2× repeat," but not C1.
The specificity of the reaction was evaluated by inhibition assays. A constant dilution of the anti-sporozoite antiserum was incubated with serial dilutions of homologous peptides prior to delivering to the wells of the microtiter plates and this was followed, as above, by treatment of the wells with 125 I-labelled goat anti-rabbit IgG. The results show that the rabbit anti-sporozoite antiserum specifically recognizes the N2, "charged", "2× repeat" and C2 peptides. Most of the reactivity of this antiserum was directed against the repetitive epitope and the C2 peptides, while titers of antibodies against the N2 peptide were rather low. The binding was specific since it was inhibited only by the homologous peptides.
EXAMPLE 5: IMMUNOBLOTTING
To rule out the possibility that the recognition of the peptides by anti-sporozoite antibodies could be the product of spurious cross reactions with irrelevant antigens present in the sporozoite preparation, the affinity-purified anti-C 2 anti-peptide antibodies were assayed by Western blotting against sporozoite extracts. The results show that these antibodies recognize both the intracellular precursor and the membrane-associated CS protein. Immunoradiometric assays of anti-C2 against the repeat peptide were negative, indicating that contaminant antibodies were not present.
Western blotting was performed as follows: Sporozoite extracts (10 5 /ml.) were subjected to electrophoresis in a 10% sodium dodecylsulfate polyacrylamide gel. The separated proteins were electrophoretically transferred to nitrocellulose sheets (as disclosed by Towbin, H., et al., Electrophoretic Transfer of Proteins From Polyacrylamide Gels to Nitrocellulose Sheets: Procedure and Some Applications, Proc. Natl. Acad. Sci. (USA) 76: 4350-4354 (1979)). The nitrocellulose paper was saturated with PBS containing 5% BSA and normal goat serum for one hour at 37° C. The various lanes were cut and each lane was incubated with a different affinity-purified anti-peptide antibody. Antibodies against "2× repeat", "charged", and C 2 peptides were used. Antiserum against whole sporozoite was used as a control. After extensive washing with PBS containing 1% BSA, the strips were incubated for 2 hours at room temperature with affinity-purified 125 I-labelled goat anti-rabbit IgG. The strips were washed, dried, and exposed to autoradiography. Two specific bands were obtained in all cases, one corresponding to a molecular weight of 52,000 daltons (intercellular precursor of P. knowlesi CS protein) and one corresponding to a molecular weight of 42,000 daltons (P. knowlesi CS protein itself). Anti-repeat activity was only detected in the wells incubated with dilutions of the anti-sporozoite antiserum.
EXAMPLE 6: ANTIBODY ELICITATION BY THE SYNTHETIC PEPTIDES
The synthetic peptides, 2× repeat, N2, and C2, were conjugated to keyhole limpet hemocyanin using carbodiimide, according to the method of Likhite, V. et al., in Methods in Immunology and Immunochemistry. Curtis, C. A. and Chase, W. A., (Eds.), Academic Press, N.Y., 1967, pp. 150-157. The conjugates were emulsified in complete Freund's adjuvant and injected into rabbits and mice. Conjugate was injected into the footpad of rabbits (500 micrograms) and mice (100 micrograms). The animals were bled 6 weeks after immunization. The antisera were assayed against glutaraldehyde-fixed sporozoites of every species of malaria parasites by indirect immunofluorescence, as disclosed by Nardin, E. H., et al. R. Bull. WHO 57 (Suppl.): 211-217 (1979). While the antisera to the repeats were strictly species-specific, i.e. recognized only P. knowlesi, the antisera to N2 and C2 also reacted with P. berghei, P. cynomolgi, P. falciparum, P. vivax, P. malariae, and P. brisilianum. When incubated with P. berghei sporozoites, both anti-N 2 and anti-C 2 gave CSP reactions. This means that that they induced formation of a prominent, tail-like, precipitate at the posterior end of the parasite, as reported by Vandenberg, J., et al., Mil. Med. 154 (Supp.): 1183-1190 (1969). All reactions were specific since they were inhibited by the homologous but not by the heterologous peptide at concentrations of 50 micrograms per microliter in the incubation medium. None of the antisera reacted with sporozoites of P. gallinaceum.
The above results indicate that C2 and N2 are exposed on the exterior of the CS molecule and that they are accesible to interaction with antibodies. Moreover, the reactivity of anti-N2 and anti-C2 with sporozoites strongly suggests that the corresponding peptides are represented on the parasite surface, and are not removed during intracellular processing. This was confirmed by immunoblotting with extracts of P. berghei and P. falciparum sporozoites.
EXAMPLE 7: IMMUNOBLOTTING OF P. BERGHEI SPOROZOITES
P. berghei (10 5 sporozoites per lane) were subjected to electrophoresis on SDS-PAGE (10%) and the proteins were transferred to nitrocellulose. After saturation with 5% BSA, and incubation with 5% goat serum, the cellulose strips, were incubated with monoclonal (anti-P. berghei) antibodies 3D11, anti-C2, or anti-N2, washed and reincubated with a second radio-labeled antibody (affinity purified goat anti-rabbit or anti-mouse immunoglobulin). The washed strips were then subjected to autoradiography. In P. berghei extracts, two specific polypeptides of Mr 52,000 and 44,000 were detected by anti-N2 or anti-C2. The 44,000 Mr protein represents the processed form of the 52,000 polypeptide and is found on the surface membrane of the P. berghei parasite. We conclude that the surface polypeptide must contain structures, most likely at the C-terminal and N-terminal ends of the molecule, closely resembling C2 and N2, respectively.
The results of this immunoblotting experiment are shown in FIG. 2. Lanes 1 and 5 are the controls, containing mouse and rabbit serum, respectively. Lane 2 contains mouse anti-C 2 , lane 3 contains rabbit anti-N 2 and lane 4 contains monoclonal anti-CS for P. berghei. Western botting with P. falciparum using the same methodology was also positive with anti-C2 and anti-N2.
EXAMPLE 8: PARTIAL NEUTRALIZATION OF P. BERGHEI SPOROZOITES BY RABBIT ANTI-N 2 (P. KNOWLESI)
Antiserum (0.2 ml), or normal rabbit serum as a control, was incubated for 45 min at room temperature with 0.5 ml of medium 199 (Gibco, Grand Island, N.Y.) containing 3×10 4 sporozoites obtained by dissection of salivary glands of Anopheles mosquitoes. After incubation, 1 ml of medium was added and 0.2 ml (5×10 3 sporozoites) were injected intravenously into five A/H mice, which were then examined daily for presence of the blood stage of the parasite. In four separate experiments, there was evidence of partial neutralization of the parasites by anti-N 2 .
Some of the mice innoculated with parasites treated with anti-N 2 did not become patent. In all experimental groups the prepatent periods were longer than those of the controls. The results are shown in the following Table 1:
TABLE I______________________________________No. of Mice Infectecd/No. of Mice Injected (Day of Patency ± SD)After Incubation of Sporozoites with:Experiment No. Anti-N.sub.2 Normal Serum Control______________________________________1 0/5 5/5 (5.6 ± 0.4)2 4/5 (6.4 ± 0.4) 5/5 (4.8 ± 0.4)3 5/5 (5.4 ± 0.4) 5/5 (4.0)4 5/5 (5.6 ± 0.7) 5/5 (4.4 ± 0.7)______________________________________
This increase in prepatent period is highly significant, considering that the dose response curve relating the dose of sporozoites injected to the first day of patency is quite flat, as reported by Schmidt, N.H., et al., Am. J. Trop. Med. Hyg. 31 (Suppl): 612-645 (1982).
In two other similar experiments, rabbit antiserum to C2, which had given a very strong CSP reaction (between mature infective sporozoites and antiserum) with P. berghei sporozoites, had no discernible effect on their infectivity for mice.
EXAMPLE 9: ALIGNMENT OF HOMOLOGOUS AREAS OF CS PROTEINS OF DIFFERENT SPOROZOITES SPECIES
The computer program ALIGN, reported by Dayhoff, M. O., et al. in Methods and Enzymology (Editors: Hirs, C. H. W. and Timasheff, S. N.) 91: 524-545 (Academic Press, N.Y., N.Y. 1983) was used to evaluate the homology between the areas containing the repeats of 3 circumsporozoite proteins: P. knowlesi, P. falciparum and P. cynomolgi.
The repeats of these three proteins are quite distinct (QAQGDGANAGQP for P. knowlesi, PNAN for P. falciparum and DGAAAAGGGGN for P. cynomolgi (the key for this notation is: A=alanine; R=arginine; D=aspartic acid; Q=glutamine; N=asparagine; E=glutamic acid; G=glycine; I=isolucine; L=leucine; P=proline; S=serine; T=threonine; Y=tyrosine; V=valine; K=lysine; C=cysteine; M=methionine; H=histidine).
The scores were significant only for the comparison between P. knowlesi and P. falciparum repeats (4.41 SD, where a score of 3.0 indicates a probable relatedness). This accounts for the fact that certain monoclonal antibodies to the P. knowlesi repeats cross-react weakly with P. falciparum, as reported in Cochrane, et al., Proc. Natl. Acad. Sci (USA) 79: 5651 (1982).
By contrast, when the ALIGN program was used to analyze the three sequences excluding the region of the repeats, the scores were all highly significant, to wit, 23.37 S.D., 24.57 S.D. and 16.28 S.D. for comparisons between P. knowlesi and P. falciparum, P. cynomolgi and P. knowlesi, and P. cynomolgi and P. falciparum, respectively.
A particularly high degree of homology, most likely sufficient to preserve the tertiary structure and the functional properties of these domains, was observed between N 2 and C 2 of P. knowlesi with peptides in the corresponding charged areas of P. falciparum (see FIG. 3). These two sequences were aligned by visual inspection to achieve the maximum degree of homology. The homologous areas are indicated by white boxes in FIG. 3. The shaded boxes show residues which are known to be frequently interchanged by single-base substitutions among homologous proteins, as established by McLachlan, A. D., J. Mol. Biol. 61: 409-424 (1971).
The extensive homology of these regions, which extends to the initial amino acids of the repeat segment of P. knowlesi, is evidence of a high degree of inter-species conservation of the structure of this region of the CS protein. This suggests that the N-terminal end of these CS molecules may be involved in an important sporozoite function.
This alignment of the homologous regions of CS proteins of different species can be used to identify homologous peptides in CS proteins of different species. Thus, the region of the P. falciparum CS protein corresponding to N 2 of P. knowlesi will have the amino acid sequence: Arg-Lys-Pro-Lys-His-Lys-Lys-Leu-Lys-Gln-Pro-Gly-Asp.
Similarly, the region of the P. falciparum CS protein corresponding to C 2 will have the structure: Lys-Pro-Gly-Ser-Ala-Asn-Lys-Pro-Lys-Asp-Glu-Leu-Ile-Tyr-Glu-Asn-Asp-Ile-Glu.
Once the amino acid sequences of such peptides are known, the corresponding nucleotide sequences can be derived. DNA fragments comprising these nucleotide sequences may be used in genetic engineering constructs in conjunction with DNA fragments corresponding to their repeats, to prepare genetically engineered antigens capable of eliciting antibodies in a host with increased neutralization activity against sporozoites. This activity crosses species lines and is therefore of considerable importance as an element in the creation of a vaccine to protect mammals against malaria. ##SPC1##
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Synthetic peptides containing non-repeating epitopes of circumsporozoite derived protein antigen and which are substantially shorter in length than the intact antigen are disclosed. The peptides when administered to a host raise antibodies in that host that will bind to the circumsporozoite antigen on the parasite. Vaccines based upon these peptides, as well as means of raising antibodies to circumsporozoite antigens using the synthetic peptides are also disclosed.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a perfection of Provisional Application No. 62/045,142, filed on Sep. 3, 2014, the disclosure of which is fully incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to an apparatus for quickly and easily manipulating flowers into evenly distributed patterns to create a flower bouquet of a specific size and shape. This apparatus joins a plurality of flower stems into a tube to form the bouquet handle resulting in a three-dimensional bouquet where each flower is situated in a fixed position and at a proper height. The invention achieves a well-balanced, aesthetically pleasing flower bouquet with repeatable end use assembly.
[0004] The apparatus allows for changes to be made to a bouquet after initial assembly/formation so that new and/or replacement flowers can be inserted and then later removed. The apparatus can be used to create a flower bouquet with any type of material; fresh flowers and greenery, artificial flowers, or other products like jeweled brooches that are increasingly popular in flower bouquets. With predefined insertion points, this apparatus minimizes floral waste. And with its preferred dome, it makes bouquet assembly easy and quick. Furthermore, this device provides for the consistent assembly of bouquets, i.e., allowing for substantially the same bouquet to be constructed at two or more locations, thereby promoting greater arrangement duplication/consistency.
[0005] The apparatus of this invention is hemispherical, preferably dome-shaped, or of another similar three-dimensional configuration, any one of which has an enhanced outer edge for rigidity containing: a specified number of flexible apertures and specifically sized slits for flower insertion, a flexible tube handle to cover the flower stems, an optional flexible fluted tube handle collar placed above the flexible tube handle to aid in covering stems coming into the tube at an angle, and a stretchable fabric-like wrapper for the tube handle. Any dome shape and size can be manufactured and used to create the desired bouquet. The outer rim of that dome can be further enhanced with a plurality of smaller, simplified apertures into which may be inserted additional complimentary greenery if needed, or as desired.
[0006] 2. Description of Relevant Art
[0007] Flower bouquet holders utilizing a foam head or a foam enclosed in a cage, with an integrated handle have been used extensively in the past. The use of these holders, however, requires some floral design experience and knowledge of the correct placement of flowers and greenery into that foam head for achieving a well-balanced, three-dimensional bouquet.
[0008] Various bouquet holders are known as shown and described in: Smithers U.S. Pat. No. 2,765,585, Hrivi U.S. Pat. No. 4,204,365, Hasty U.S. Pat. No. 5,070,644. Graham et al U.S. Pat. No. 5,454,189, Ghiotti U.S. Pat. No. 6,862,841 and Miller U.S. Pat. No. 7,310,910. Some disadvantages with the foregoing devices include: (1) the floral design experience needed to assure that flowers get placed in the correct positions for achieving a well balanced bouquet; (2) the foam area available is quite limited. So, after a flower is inserted into the foam, valuable space is taken up thus further limiting the amount of space remaining for additional flower stems; (3) if a designer removes a flower from the foam and inserts another flower therein, it is difficult to re-use the empty hole and assure that his/her replacement flower stem will remain secure in that foam base; (4) the foam head, with repeated insertions and occasional stem removals, begins to break down or disintegrate, thereby leading to flowers falling out from the arrangement prematurely. That, in turn, requires securing such flowers back in the assembled bouquet with wire or other fastening devices. Finally, (5) the aforementioned plastic handles are sometimes difficult to hold, especially for extended periods of time, and have been known to bend with heavier flower arrangements.
[0009] Although not for specific use as a hand-carried bride's bouquet, Matteucci U.S. Pat. No. 5,758,452 and the Fresh Flower Bouquet System of Foster Published U.S. patent application Ser. No. 11/217,416 (2006) utilize a vase or vessel grid-like cap, wherein flowers are inserted into grid holes. There are also problems with any flat grid system. They are two-dimensional, and require a more experienced, or professional, floral designer to arrange the flowers three-dimensionally therein. As such, they are not conducive towards assembling into a hand-held flower bouquet, let alone repeatable duplicative bouquets.
[0010] For traditional hand-tied bouquet methods that do not utilize a foam-type bouquet holder, the assembly of a flower bouquet is not straightforward and rather time-consuming. With or without a foam head device or grid, the assembly of any flower bouquet requires knowledge of: (1) floral design methodology in the selection of product, (2) the correct placement of flowers to achieve the desired result, and (3) the correct use of floral industry tools and supplies (such as picks, tapes, wires and the like) for properly securing a flower arrangement.
[0011] Use of these fastening products to create a hand-held flower bouquet is a time-consuming process because it must first be decided where to place the next flower. Each flower must then be fastened to the bouquet . . . one flower at a time.
SUMMARY OF THE INVENTION
[0012] The present invention is an apparatus that quickly and easily creates a three-dimensional bouquet that is proportionally correct and well balanced with each flower duly secured into a fixed position and at the correct height.
[0013] Brides may request a bouquet of any size or shape. The device of this invention would likely be manufactured for accommodating at least three sizes. But for purposes of this disclosure, no specific dimensions are given as the bouquet size could vary, depending on latest trends, customer preference, different shapes that may come into style.
[0014] The apparatus, generally 10 includes a main holder 12 that is available in several configurations (round, tear-drop or other geometrical shape) and in varying sizes: 8-12″ for a typically round wedding bouquet or 6″ for a nosegay. Sometimes, the overall size of a flower arrangement may vary with the bride's desires, strength (i.e., ability to carry a heavier bouquet) and/or body shape (i.e., smaller arrangements for shorter or more petite framed brides). Still other potential shapes include a cascade, crescent, Hogarth (or S-curve), diagonal, heart, triangular (or pyramidal), oval or horizontal-shape with flowers flowing down from the arm or hand-held arrangement. The larger of these shapes, especially the oval and/or horizontal varieties, are suitable for use as table centerpieces. Each holder will contain a plurality of apertures (or slits) 20 for accepting flower stems F, usually one stem per aperture.
[0015] The apparatus includes a tube 60 and optional tube collar 30 for “housing” a plurality of flower stems F. The tube 60 and tube collar 30 are made of flexible plastic sheet rolled into the shapes shown. Slits 40 in the upper half of tube collar 30 permit its further expansion to provide additional coverage of stems F as they converge at a joining point.
[0016] The tube 60 and tube collar 30 may be manufactured from plastic or any other malleable material such as aluminum. Ideally, both may be bent (or hand-molded) to provide a more comfortable grip for the eventual bouquet carrier/holder. Tube 60 and tube collar 30 may also be manufactured in any color and/or texture (embossed). The tube 60 may be fully or partially encrusted with glued-on crystals, pearls, jewels or other ornamentation, thereby eliminating the need for a ribbon or other wrapper 80 thereover.
[0017] The present vertical split 70 in tube 60 and vertical splits 40 in tube collar 30 may be pulled open, and using the expansion resistance present, hold the multiple flower stems F in place. Tube collar 30 and tube 60 may also be easily slipped onto (or over) these flower stems F from the bottom of the assembled arrangement and then pulled up to the highest joining point of the flower stems F, provided the overall diameter of the joined stems F does not exceed the diameter of tube 60 .
[0018] A stretchable fabric-like sleeve (wrapper) 80 is shown having the same diameter as tube 60 and may completely cover it.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Further features, objectives and advantages for these inventions will become clearer when referring to the following detailed description made with reference to the accompanying photographs in which:
[0020] FIG. 1 is a side plan view of one embodiment of bouquet holder apparatus according to this invention broken down into its primary components, i.e., a main holder (its dome-shape being representative), a tube collar, a tube wrapper and one representative stemmed flower for inserting into one of the apertures in the main holder;
[0021] FIG. 2 is a top perspective view of just the main holder (dome) from FIG. 1 with its plurality of primary apertures 20 ;
[0022] FIG. 3 is a top plan view of the main holder (dome) from FIG. 1 ;
[0023] FIG. 4 is a side plan view taken along lines IV-IV of FIG. 3 ;
[0024] FIG. 5 is a top perspective view of a first alternate embodiment of domed main holder with its plurality of primary apertures 120 and smaller secondary apertures 126 ;
[0025] FIG. 6 is a top plan view of the alternate main holder (dome) from FIG. 5 ;
[0026] FIG. 7 is a side plan view taken along lines VII-VII of FIG. 6 ;
[0027] FIG. 8A is a top view of a first embodiment of aperture/slit 24 according to this invention;
[0028] FIG. 8B is a top view of a second embodiment of aperture/slit 123 , 124 ;
[0029] FIG. 8C is a top view of a third embodiment of aperture/slit 224 ;
[0030] FIG. 8D is a top view of a fourth embodiment of aperture/slit 324 , with optional slits 325 ;
[0031] FIG. 8E is a top view of a fifth embodiment of a gapped aperture/slit 426 ;
[0032] FIG. 8F is a top view of a sixth embodiment of a five-standing aperture/slit 524 ;
[0033] FIG. 9 is a front perspective view of an optional tube collar 30 with slits 40 for allowing extra room for the expansion of flower stems between flower head and tube collar 30 . It includes a vertical slit 50 that lets this tube collar expand for the wrapping of stems therein. It also shows a tube 60 as the flower bouquet handle, said tube having a vertical slit 70 that permits expansion for wrapping around gathered stems;
[0034] FIG. 10 is a side view of the optional stretchable tube wrapper 80 ;
[0035] FIG. 11 is a side view of a completed flower bouquet using the apparatus of this invention;
[0036] FIG. 12A is a top plan view of a first alternative configuration for a cascade-shaped arrangement;
[0037] FIG. 12B is a top plan view of a second alternative configuration for a crescent-shaped arrangement;
[0038] FIG. 12C is a top plan view of a third alternative configuration for a Hogarth (or S-) curve shaped arrangement;
[0039] FIG. 12D is a top plan view of a fourth alternative configuration for a diagonal-shaped arrangement;
[0040] FIG. 12E is a top plan view of a fifth alternative configuration for a heart-shaped arrangement;
[0041] FIG. 12F is a top plan view of a sixth alternative configuration for a triangular-shaped arrangement;
[0042] FIG. 12G is a top plan view of a seventh alternative configuration for an oval-shaped arrangement; and
[0043] FIG. 12H is a top plan view of a seventh alternative configuration for a horizontal-shaped arrangement.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0044] When referring to the alternate embodiments of main holders (dome-shaped or otherwise), apertures/slits, etc. herein, it is to be understood that common components will be commonly numbered though in the next hundred series.
[0045] While shown in a round, hemispherical or dome shape, it is to be understood that still other configurations/shapes may be practiced according to this invention. For instance, for a table centerpiece, there may be an elongated bread loaf-shaped, centerpiece flower holder. For still other bride-desired arrangements, pre-shaped apparatus may include a main holder that is; cascade-shaped, like element 212 in FIG. 12A ; crescent-shaped like holder 312 in FIG. 12B ; Hogarth or S-curve shaped like holder 412 in FIG. 12C ; diagonal shaped like holder 512 in FIG. 12D ; heart-shaped like holder 612 in FIG. 12E ; triangular (or pyramidal)-shaped like holder 712 in FIG. 12F ; oval-shaped like holder 812 in FIG. 12G ; and/or horizontal-shaped like holder 912 in FIG. 12H . All such alternate configurations include one or more of the various inventive aspects described below.
[0046] Referring to FIGS. 1 through 4 , main holder (dome) 12 of apparatus 10 is configured to have a hemispherical cross-sectional shape, from the top 14 of that dome to its base or lower perimeter/edge 16 . Each dome 12 will include a plurality of apertures (or slits) 20 , usually inside of a surrounding circular perimeter 22 with a crosscut 24 across the diameter of perimeter 22 in two or more locations of each aperture/slit 20 . These apertures/slits 20 are situated a predefined distance from one another, each aperture/slit being capable of holding the stem of a flower F pushed therein. In the case of this preferred dome configuration, there is also an uppermost, central aperture 18 .
[0047] These apertures/slits 20 should have sufficient flexibility for pulling through materials with one or more leaves attached (intact). The larger leaves might need to be removed, but smaller materials/greens may be pulled through such apertures. This applies to both artificial and fresh flower arrangements.
[0048] Main holder 12 is preferably constructed of plastic as that term is used in a generic sense. It could be a polyvinyl chloride PVC, a sufficiently rigid PTFE blend or other composite-like construction. A rigid synthetic plastic is preferred for its construction, with flexible slits/holes or apertures 20 . Alternately, main holder 12 may be made from a polycarbonate shell using rubber-like silicone about its apertures 20 . To a lesser preferred degree, main holder 12 could be constructed of a non-plastic material such as aluminum provided it is rigid enough to withstand the force of repeatedly pushing or pulling flower stems F (live or artificial or both) through its apertures 20 without collapsing.
[0049] During assembly, the heads to the respective flowers F shall come to rest on an uppermost surface of main holder 12 . As such, this dome prevents the bunch of flower heads from being placed too high or too low in relation to the one another.
[0050] The stems of flowers F that are inserted shall protrude loosely below main holder (dome) 12 while the remaining flowers F get inserted into other apertures/slits within this main holder 12 . A first flower F is inserted into the centermost aperture 18 , with other flowers F added sequentially, working from the inner circle to the outer rim of the dome all the way down to its lowermost perimeter 16 . Except for this centermost first flower F, the user may elect to slightly bend or curve the stem from its flower head to approximately 5″ down. This will help hold all other (subsequent) flower stems in the center of the arrangement.
[0051] Excess greenery from the bottom two thirds of each flower stem F may be removed prior to insertion into its aperture 20 . Determination of any additional greenery to be removed from the flowers may be made after final assembly, as greenery in the upper third of the stem (just below the main holder 12 ) will usually provide adequate coverage of bare stems. The purpose of removing the lowest leaves from the respective flowers avoids having these leaves take up unnecessary space within tube 60 .
[0052] The thickness of the combined stems may be greater than the diameter desired for the bouquet handle. One solution is to first insert all of the flower stems into their apertures 20 before cutting any number of stems to a depth below the top rim of tube collar 30 . Then using any floral adhesive, the arranger should secure the cut and loose stem to the tube collar and/or adjacent stems if needed.
[0053] Additionally, the area below main holder 12 may be enhanced with a decorative base of tulle, lace, or other fabric that will be secured in place when the tube collar 30 is pushed up to the joining point for all the flower stems. This addition of decorative product (inserted between the tube collar 30 and underside of main holder 12 ) helps fill in any gaps and assists in camouflaging those sections of flower stems extending below the main holder 12 . Slits 40 in the upper half of tube collar 30 may expand to provide additional coverage of any stem extensions from the dome to the common joining point.
[0054] Vertical split 50 in tube collar 30 may be used to force (or split open) the tube collar 30 . Using the expansion resistance present, it can then wrap and hold the flower stems in place. Alternately, tube collar 30 may be slipped up and over the flower stems F from the bottom of the arrangement. There, it can be pulled/raised to the highest possible joining point of the combined stems provided the overall diameter of these joined stems does not exceed the maximum diameter of tube collar 30 bottom.
[0055] Tube 60 can cover the remaining flower stems while further serving as the bouquet handle. A vertical split 70 in tube 60 may be used to force (or split) it open sufficiently for wrapping and holding the flower stems in place using the expansion resistance present. Alternately, tube 60 may be slipped over these stems from the bottom of the arrangement and pulled up to the highest possible point before slipping into the bottom of tube collar 30 , if utilized, or pushed to the topmost convergence point of the stems, provided the overall diameter of the joined stems does not exceed the maximum diameter of tube 60 .
[0056] Towards completion of the arrangement, the user will determine if it's necessary to turn the flower heads or fluff the petals to cover any gaps (empty spaces). To incorporate fillers or other secondary or tertiary material, the user may make use of the same apertures as used for the main flower, or incorporate material into a plurality of smaller, secondary apertures shown as element 126 in FIGS. 5 through 7 , for example. Furthermore, the apertures/slits, themselves, may assume the standard size and shape (across the full diameter of a circular surround 22 , 122 , 222 , 322 , 422 , 522 , 622 and 722 as shown in the accompanying drawings). Or, as shown in the alternate slit shapes of FIGS. 8B through 8F , these same slits may include: a larger central aperture 123 with cut lines 124 extending outwardly therefrom ( FIG. 8B ); between three to eight cut lines alone ( FIG. 8C depicting a trio of such for representative purposes), none of which extend from circular perimeter to circular perimeter; a plurality of main cut lines 324 , with optional additional cuts shown in dotted lines 325 in FIG. 8D ; a purposefully gapped set of cut cross-sectional lines, spaced apart as per element 426 in FIG. 8E ; and/or a set of cut lines ALONE, element 524 in FIG. 8F , without any “formal” circular perimeter surround. The intent behind any such aperture/slit configuration is to maximize how far the aperture can be spread “open” for the passage of thicker stemmed flowers (live or artificial) therethrough without detrimentally impacting the chance for subsequent removal of flowers and possible reuse of the main holder in another, second flower arrangement. These various aperture/slit configurations should accommodate various flower stem “sizes” without ripping the underlying “holes” too excessively.
[0057] A standard dimension for a hand-tied bouquet handle is usually about two hand-lengths (or an average of about 7.5 to 8 inches long). Ideally, tube 60 may be manufactured with one or two break away sections that can be easily removed using perforations built into tube 60 . They can provide for an immediate adjustment to the overall height/length of tube 60 as desired.
[0058] When using fresh flowers, stems may be purposefully left protruding from the bottom of tube 60 to enable suspension of the assembled bouquet in a water container for maintaining freshness of the arrangement until needed. In some instances, the final bouquet design may leave these protruding stems. But more often, such stems are cut to a blunt and even edge before being encased in a wrapping.
[0059] When using artificial flowers, their lower stems may also be left protruding from the bottom of tube 60 for a more “natural” appearance. Otherwise, for both artificial and fresh flowers, excess stem lengths may be trimmed away with wire cutters for artificial flowers and with scissors or a florist's knife for fresh (or live) flower arrangements. A stretchable fabric-like sleeve (wrapper) 80 having about the same diameter as tube 60 may then be used to cover the handle. Manufactured from any number of materials, this wrapper could be provided in any number of colors or styles.
[0060] Prior to wrapping tube 60 with stretchable tube sleeve 80 or any other wrapping material, it is important for the arranger/assembler to secure the bottom of stems to tube 60 using OASIS brand Floral Adhesive, acceptable for use on both fresh and artificial materials. After allowing the glue to dry for 24-36 hours, the stretchable sleeve 80 or other wrapping is attached there over.
[0061] Other tube 60 wrappers might include ribbon, raffia, tulle, lace and fabric trim. Additionally, tube 60 may be covered with glued-on crystals, pearls, jewels or other material that will match the colors of the event (i.e., wedding colors).
[0062] To a less preferred extent, it may be desired (in some instances) to add another piece to the device, namely a snap-in bottom shield (not shown) for beneath the main holder. Like a concave-shaped, salad bowl cover, it would be rigid while also connecting to/about the tube.
[0063] It may also be prudent to assist less-experienced arrangers by adding some type of color coding system about the various aperture surrounds (also not shown). In that instance, larger holes may be coded in green surrounds, medium-sized holes in blue and the smallest holes for accessorizing greenery in red surrounded holes.
[0064] Having described the presently preferred embodiments, it is to be understood that the invention may be otherwise embodied within the scope of the appended claims below.
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A reusable flower bouquet arranging apparatus is presented for creating a hand-held bouquet with a hand tied appearance as would be used for a wedding bouquet or nosegay. Made from plastic with a plurality of spaced apart apertures, it can be used to make arrangements having an overall shape that is domed, cascading, crescent-shaped, heart-shaped, oval or several other configurations.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/633,460 filed Dec. 6, 2004, the disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an airplane seat, a passenger bench for an aircraft, a magnetic field resonance system, and a use of a device for generating electromagnetic interaction in an airplane seat or in a passenger bench for an aircraft.
[0003] Long-distance flights, long journeys in passenger motor vehicles or coaches in confined spaces entail an uncomfortable seating position for passengers. Apart from the passengers, members of the crew are also affected. Remaining in the same seated position, combined with limited opportunities to move around, in many cases leads to the danger of suffering from thrombosis. Moreover, long journeys can entail changes in time zones. If such journeys are made in confined spaces, the body can experience stress situations, and manifestations can be experienced which, for passengers and aircrew alike, can lead to the phenomenon known as jet lag.
[0004] DE 103 04 085 A1, DE 103 04 093 A1, DE 103 02 439 A1 and DE 103 01 867 A1 disclose devices which are based on the principle of electromagnetic resonance stimulation (eMRS). One example of this is the eMRS® system of the company vita-life®.
vita-life® eMRS® can for example be used as supplementary treatment: for regenerative function—bone system; for regenerative function—soft tissue; as a relaxation function—vegetative soothing; for improved provision of oxygen; as a function that stimulates circulation; as a pain-relieving function—bony joint system; and as a pain relieving function—connective tissue.
[0013] The function of the devices is based on the effect which electromagnetic and magnetic fields have on living organisms.
[0014] First there was the empirical knowledge of old cultures with the positive effect of magnets on health and beauty. After a considerable period when this was forgotten and after a brief reawakening of the interest in medieval times and at the beginning of the modern age, magnetic-field research made its breakthrough by recognising the pathogenesis as a result of a lack of electromagnetic information. There followed a phase of euphoric, uncritical and undifferentiated use: in cosmetics, in the wellness sphere, and in conjunction with other fashion trends. This boom caused considerable damage to serious magnetic field research. The latter has increasingly been classified as frivolous and thus not to be taken seriously.
[0015] Irrespective of these western fashion trends, however, above all in Europe intensive high-level research has continued without interruption. In the early 21st century, as part of information medicine and energy medicine, there has again been an increased focus on the therapeutic options of electromagnetic waves, and, in the context of environmental medicine and the problematic nature of electrosmog, this research discipline attains a dimension of urgency.
SUMMARY OF THE INVENTION
[0016] According to an embodiment of the present invention, an airplane seat is disclosed which comprises an accommodation region and a device for generating electromagnetic interaction. This device for generating electromagnetic interaction is designed such that it generates electromagnetic interaction in the accommodation region. In this arrangement the accommodation region is designed to accommodate an object, and the device for generating electromagnetic interaction is accommodated in the seat, in particular integrated in the seat.
[0017] This may allow to prevent stress situations for humans.
[0018] Furthermore, the invention provides for a bench that comprises a plural number of seats with the characteristics described above, wherein the seats are arranged side by side.
[0019] Moreover, according to the invention a means of transport is provided, comprising a seat or comprising a bench with the characteristics described above.
[0020] In addition, the invention states a magnetic-field resonance system that is designed for operation in an aircraft. The term “magnetic-field resonance system” refers in particular to a device by means of which magnetic-resonance therapy can be carried out, i.e. by means of which humans can be treated in a targeted way using electromagnetic fields.
[0021] Also, the invention discloses the use of a device for generating electromagnetic interaction in a seat or in a bench.
[0022] Electromagnetic interaction is one of the four basic forces of nature; the others being gravitation, week interaction and strong interaction. Electricity and magnetism are manifestations of electromagnetic interaction. Electromagnetic interaction describes the influence which purely electric, purely magnetic or electromagnetic fields have on objects and spatial characteristics.
[0023] A device for generating electromagnetic interaction in the accommodation region can result in electromagnetic interaction with an object, situated in the accommodation region, taking place. For example, the object can sit or lie in the accommodation region while the electromagnetic interaction has an effect on the object. Advantageously, on a seat with an integrated device for generating electromagnetic interaction, electromagnetic interaction can thus take place so as to be directed to the seated object (for example a human being or an animal). Such electromagnetic interaction has a positive effect on the object, triggered by the interaction of material of the object with an electric and/or magnetic field. In this way stress situations in the object can be reduced, or they can be prevented from arising in the first place—wherein such stress situations can in particular occur during a journey, which stress situations a person can for example suffer in a means of locomotion—when seated on the seat according to the invention.
[0024] Electromagnetic interaction can be regarded as the basis of all life. The physiology of the turn of the millennium is on the brink of a revolution in the biological sciences. The fundamental significance electromagnetic forces have on living systems is becoming increasingly clear. Seeing the organism as a self-regulating complex system with its own communication options and control options leads to an ever more profound understanding of life, and to completely new approaches to therapy. Life is characterised by metabolism, growth and propagation.
[0025] The metabolism is controlled by way of electromagnetic processes: for example, by way of electrical potentials on the cell membrane, ions are also “pumped” against concentration gradients (active metabolism). The body's water management and electrolyte management is partly based on phenomena which are connected to electromagnetic interaction. Communication with the outside world, information transmission, the function and coordination of inner organs and muscular contractions, including those of the myocardium (ECG) take place by electrical stimulation (NS). Likewise, the brain's increased nerve activity and ability to function is based on bioelectricity (EEG). In an object, for example in the human body, magnetic fields as particular instances of electromagnetic interaction can cause changes that are similar to those that arise during exercise, and can thus support normal biological processes. Biological effectiveness of a generated alternating magnetic or electromagnetic field can arise as a result of:
electromagnetic influence the field has on the ion currents in an object, for example a human body (for example sodium-potassium pumps, Ca-cascade); magnetomechanical influence the magnetic field has on the oscillation amplitude of cells and organs (resonance); ionic-cyclotronic resonance of anions and cations of the bodily fluids of an object to strengthen the intrinsic rotational momentum (spin); nuclear magnetic resonance (NMR); and electron spin resonance (ESR).
[0031] Advantageously, electromagnetic interaction can give rise to biophysiological effects. The term “biophysiological effects” refers in particular to the bioelectrical effect, the biochemical effect and the bioenergetic effect.
[0032] The bioelectrical effect can for example cause normalisation of a cell membrane. In pathological cases the potential can drop as a result of the ingress of positive ions, for example of Na+, into the interior of the cell. In order to reverse this process, the cell requires energy which it can obtain from ATP hydrolysis.
[0033] The biochemical effect is based on an increase in enzyme activity, as well as on activation of the oxidation-reductive processes that are connected with ATP. In this, the Ca++ that has been produced from the Ca-cascade is the effective ion.
[0034] The bioenergetic effect is a factor that stimulates nutrition and cell growth. Furthermore, this effect controls intracellular processes that lead to regeneration of the body.
[0035] In many various ways over the past years the effectiveness of pulsating electromagnetic field therapy has been proven and made visible.
By means of dark-field microscopy the resolution of pseudohaemagglutination (rouleaux formation) of erythrocytes can be proven. This leads to improvements in blood viscosity, improvements in blood-flow characteristics, enlargement of the surface, increased oxygen content, and reduced danger of thrombosis. Bone density measurements make it possible to detect a significant increase in bone density after treatment over an extended period of time. Infrared thermography measuring provides proof of improved blood circulation. Measuring the skin conductance potential at acupuncture-meridian end points (PROGNOS method) documents regulation of body energy. Combined biofeedback measuring shows optimisation of a multitude of body functions after just a few minutes of applying pulsating magnetic fields. Photoplethysmography measurements show improvements in blood circulation averaging in excess of 45% in the region of microcirculation, and an increase in oxygen saturation in the blood averaging 25%.
[0042] By means of the invention, stimulation of melatonin production and stabilisation of the waking-sleeping rhythm, in particular during a journey, may be brought about, during which a human being is seated on the seat according to the invention. This can advantageously counteract an energy deficit or jet lag. An object, in particular a human being, passenger or member of the crew of an aircraft or some other means of transport or means of locomotion (for example a passenger motor vehicle, lorry, coach, ship etc.) can thus arrive from a long journey in a relaxed state and without fatigue. Thus, according to one embodiment the invention implements a magnetic resonance system in a seat so that already during a journey actively impending stress situations that would otherwise lead to jet lag and similar phenomena are counteracted. Implementing a device for generating electromagnetic interaction (i.e. an electromagnetic force) in a seat thus provides a particularly favourable field of application for such a device, because in this way real-time causes of a stress-situation can be countered.
[0043] Likewise, an improvement in the oxygen supply and nutrient supply as well as in the blood circulation can take place. As a result of this improved oxygen supply in the tissue, in this way the thrombosis danger can be reduced in a way that is similar to performance optimisation that can be carried out in top-class sports by means of electromagnetic interaction.
[0044] Through this effect during seated activities, for example during a flight, the health, well-being and performance of passengers, pilots and cabin crew can be maintained and improved through the use of electromagnetic resonance stimulation (eMRS). In this way, treatment after a journey, in particular after a flight, can be avoided. For example an MRS system is stated in DE 103 04 085 A1.
[0045] Improved blood circulation and oxygen uptake in passengers should result in the danger of circulatory disturbances and thromboses being reduced. By integrating a device for generating electromagnetic interaction in a seat, in particular in the case of aircraft, seats for various applications can be produced. It should be weighed up whether seats according to the invention are to be used for a particular group of passengers, for example first-class passengers or business-class passengers, or only as seats for the crew.
[0046] By using a device for generating electromagnetic interaction, in particular a magnetic-field resonance system, and furthermore in particular an electromagnetic resonance stimulation system (eMRS), electromagnetic interaction in an accommodation region for accommodating an object, of a seat or a bench, can be generated.
[0047] Preferred improvements of the invention are disclosed in the dependent claims.
[0048] According to exemplary embodiments of the invention, an airplane seat is stated in which the device for generating electromagnetic interaction is integrated in various elements of the seat. The device for generating electromagnetic interaction can be integrated in the seat surface, the backrest or the footrest, or in any desired combination of these three components of the seat.
[0049] Advantageously, integration of the device for generating electromagnetic interaction in elements of the seat makes it possible for the device not to be visible outside the seat and for said device to be accommodated in a space-saving manner, which is of importance in particular in means of transport such as a passenger aircraft. To a user of the seat, the seat is no different to look at than a known seat. For example, an object, i.e. for example a passenger, can be in the accommodation region of the seat.
[0050] As a rule, different body regions of a passenger are located in the region of the various seat elements. For example, the legs of a passenger tend to be on the seat element footrest, while the posterior region and the back region respectively of a passenger tend to be near the seat surface and the backrest respectively. In this way the effect of electromagnetic interaction on various body regions of the passenger can be matched in a controlled and targeted manner to physiological requirements.
[0051] Furthermore, the use of magnetic mats or one or several coils to generate electromagnetic interaction becomes possible. The device for generating electromagnetic interaction can be a coil or a magnetic mat. Often a magnetic mat comprises a coil whose form is matched to the mat. This coil or magnetic mat can be controlled by a control device.
[0052] According to a further exemplary embodiment of the present invention, the airplane seat comprises a user interface which is designed for user-defined adjustment of the electromagnetic interaction. Advantageously, by means of a user interface (for example some kind of remote control) a user is put in a position to make individual adjustments to the electromagnetic interaction. Users can thus match the effect to their individual requirements. For example, adjustment of the strength of an electric, a magnetic, or an electromagnetic field that acts on the user, in particular a passenger, can be made.
[0053] Advantageously, a user interface that is provided for setting the parameters of electromagnetic interaction could be integrated in an already existing control terminal or entertainment system. A user interface could also comprise a device for accommodating a chip card, on which a program code with instructions for the various settings is stored, and could load this code to the control unit from where it can be executed. Exchangeable chip cards provide an advantage in that at any time new characteristics and improvements of the system can be used, and in that the functionality can be optimally matched to a user (for example to body dimensions, gender, known illnesses, etc.). For example, a chip card could be provided specifically for a wellness program. A device for generating electromagnetic interaction with a wellness program would have the objective of creating a particular situation of well-being for the user. A further example relates to a chip card with a fitness program, which preferably could for example ensure improved blood circulation.
[0054] According to a further embodiment of the present invention, the seat comprises a sensor device which is designed to acquire a physiological parameter of an object arranged in the accommodation region. By means of the physiological parameter obtained, the device for generating electromagnetic interaction can be controllable. A sensor device could for example be a biofeedback sensor to determine the body state, at the time, of a user of the seat. The signals that are obtained from the body of the user can be transmitted to the seat, in particular to a control unit. This control unit can adjust the electromagnetic interaction (for example an electric, magnetic, or electromagnetic field strength) according to the state of the body of the object. Examples of measured values which could be used as biofeedback signals include skin resistance measuring, an electromyogramme (EMG), the temperature of the skin, an electroencephalogramme (EEG), oxygen-particle pressure measuring, or heart rate variability (HRV).
[0055] Biofeedback relates in particular to the feedback of measured data to the patient in order to influence his/her involuntary or unconscious bodily functions. Feedback of measured data need not necessarily be to the patient, but instead can be to therapy devices which as a result of the information obtained in this way can automatically adjust the course and dose of therapy in such a manner as to achieve maximum effect.
[0056] By means of biofeedback components, automatic control of the treatment procedure can take place. A finger sensor with which the heart rate variability (HRV) is continually measured is one example of a biofeedback sensor or a sensor device. The measured data cause real-time adjustment of the dosage, for example of an electric, magnetic or electromagnetic field. HRV as an energetic diagnostic method can be of interest because it measures a parameter which provides information on the entire organism of an object, rather than just providing a momentary snapshot at a specific point.
[0057] The finger sensor can be connected to the finger of an object or of a seated user and provides feedback that can be used for determining the dosage.
[0058] Advantageously the use of a sensor device makes it possible, in an effective and user-specific manner, to adjust electromagnetic interaction.
[0059] According to a further exemplary embodiment of the present invention, a display unit for the seat is stated. The display unit can be designed such that it can provide a colour spectrum to an object arranged in the accommodation region.
[0060] The provision of a colour spectrum, in particular of a colour spectrum that progressively changes in a determined temporal sequence, can assist in providing relaxation to objects, such as for example human beings. For example, a pair of colour-light spectacles can generate any desired colour of the entire colour spectrum from the primary colours red, green and blue. The three primary colours can be superimposed behind a diffuser screen such that a desired colour is generated. This desired colour can for example act on an open eye of the user. This can lead to a relaxed state of the user, which state can amplify the use of a concurrently acting electromagnetic interaction. This can for example in an aircraft prevent a passenger or a member of the crew from becoming fatigued. Further examples of a colour light component can include a monitor, a liquid crystal display or spectacles comprising a device for generating a colour spectrum. For example a display unit is stated in DE 103 01 867 A1.
[0061] According to a further exemplary embodiment of the present invention, a seat which comprises an acoustic playback unit is stated. The acoustic playback unit can be designed such that a frequency spectrum can be provided for an object that is arranged in the accommodation region. By means of the acoustic playback unit, for example a sound component, in particular headphones or a loudspeaker, frequencies can be provided to a user, which frequencies can amplify the effect of electromagnetic interaction, for example of a magnetic field, an electric field or an electromagnetic field. The display unit and the playback unit can also form part of an entertainment system that is for example present as standard equipment in passenger seats in an aircraft. A control device can handle coordination between acoustic signals for the sound components and can also handle the optical signals for the colour-light spectacles depending on the electromagnetic interaction.
[0062] The frequencies provided can for example be designed to generate music, vibrations or ultrasound.
[0063] The electromagnetic interaction can be a magnetic, electric or electromagnetic field. This field can be static, homogeneous or pulsating with a pulse form that can be predetermined in a targeted way. The pulse form can be from the group of a triangular form, a rectangular form and a sawtooth form. The term “sawtooth form” in particular refers to a multiple sawtooth pulse form which represents an overlay of a multitude of sawtooth forms. The frequency or the magnetic flux density can be varied in order to achieve certain effects. Practical experience has shown that pulsating magnetic-field systems can be even more advantageous than static magnets. Pulsating electromagnetic resonance systems with maximum flux densities of applicator-radiation of 1 to 500 μT, preferably 200-400 μT, can be therapeutically sensible. Integrating a magnetic-field resonance system in a passenger seat, cabin crew seat or cockpit seat can contribute to a reduction in jet lag and in a reduction in the danger of thrombosis, and increase the general well-being by promoting relaxation, sleep and stress reduction.
[0064] For example, a system for generating a homogeneous magnetic field is stated in DE 103 04 093 A1.
[0065] For magnetic-field therapy, preferably so-called extremely low frequency electromagnetic fields (ELF-EMF) are used, whose electrical parameters are smaller than, or equal to, those of the terrestrial magnetic field, while the intensity of its magnetic field is larger than, or equal to, that of the terrestrial magnet.
[0066] External magnetic fields have an effect on the charged particles that are present in biological systems. Said magnetic fields can deflect said particles (Lorentz force, Hall effect) and focus their radiation.
[0067] Magnetic fields with a frequency of 16 Hz have an influence on the cell membrane permeability of Ca-ions (cyclotron resonance). Apart from having such an influence on the ion flow, magnetic fields can also have an influence on paramagnetic particles, for example in coenzymes or prosthetic groups (for example the iron centre in the haemal plane of haemoglobin or myoglobin) and thus can have an influence on enzyme activity. They have an effect on liquid crystals and thus have an influence on membrane structures.
[0068] As a consequence of these biophysical mechanisms, various influences on metabolic activities occur. This includes effects on oxygen absorption of haemoglobin and cytochrome, tissue repair mechanisms and wound healing, osteogenesis, cardiovascular system and metabolic processes in nerve tissue and thus also in the central nervous system, as well as vasodilative, antiphlogistic and analgesic effects.
[0069] From this action spectrum, potential options of use arise in a large number of indications, for example pain syndromes, chronic inflammation, disorders of the locomotor apparatus, in particular in conjunction with osteogenesis, as well as ischaemia and circulatory disturbances, metabolic disorders, vegetative dysfunction and states of anergia.
[0070] In a positive manner the positive effects, in particular on circulatory disturbances and states of anergia, can contribute to the electromagnetic interaction contributing to a reduction in the danger of jet lag as well as to a reduction in the danger of thrombosis and an increase in the general well-being of a passenger or member of the crew of a means of transport.
[0071] According to a further exemplary embodiment of the present invention, a seat is stated which is constructed as a passenger seat. Advantageously the accommodation region of such a passenger seat can accommodate a passenger to be transported. It is thus possible to provide a transport service while simultaneously a positive influence as a result of electromagnetic interaction with the passenger or the member of the crew takes place. A passenger seat according to the present invention can be used in various means of conveyance, locomotion or transport, such as for example an aircraft, coach, tram, train or ship.
[0072] According to a further embodiment of the present invention, a bench is stated that comprises a plural number of seats which are arranged one beside the other. Providing a bench with several individual seats provided one beside the other makes it possible, for example, to install seats in an aircraft more effectively. In one attachment operation a plural number of seats that are arranged one beside the other can be installed, for example in an installation rail in the floor of an aircraft. This can accelerate the installation process during production of an aircraft. A device for generating electromagnetic interaction can be provided that is shared by all or by a part of the seats of a bench, which results in considerable cost advantages.
[0073] According to a further embodiment of the present invention, a magnetic-field resonance system for operation in an aircraft is disclosed. The use of a magnetic-field resonance system in an aircraft can require adaptation to the framework conditions that exist in an aircraft. It may be necessary, for example, to produce magnetic-field resonance systems which are adapted to the voltage, frequency or special connections (plug, socket) common in aircraft. These requirements can be different from requirements in other fields of application, for example domestic situations. It might for example also be necessary for the connections to be adapted to a current-rail system that is normally used in aircraft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0074] Below, embodiments of the present invention are described in detail with reference to the following figures.
[0075] FIG. 1 shows a functional diagram of a device for regulating electromagnetic interaction, according to one embodiment of the invention.
[0076] FIG. 2 shows a lateral section view of a seat with a device for generating electromagnetic interaction, according to an exemplary embodiment of the invention.
[0077] FIG. 3 shows a diagrammatic rear view of a seat with a device for generating electromagnetic interaction, according to an exemplary embodiment of the invention.
[0078] FIG. 4 shows a device for generating electromagnetic interaction, according to an exemplary embodiment of the invention.
[0079] FIG. 5 shows a sensor device according to an exemplary embodiment of the invention.
[0080] FIG. 6 shows a passenger with an acoustic playback unit and a display unit according to an exemplary embodiment of the invention.
DETAILED DESCRIPTION
[0081] The illustration in the figures are diagrammatic and are not to scale.
[0082] Identical or similar components in different figures have the same reference characters.
[0083] FIG. 1 shows a functional diagram of a device for regulating electromagnetic interaction. The central control device 2 determines inputs of the user interface 4 and of the sensor device 8 . The data obtained by way of the user interface 4 or the sensor device 8 is processed in the control or regulating device 2 and is converted to signals for the acoustic playback unit 10 , the display unit 12 and the device 6 for generating electromagnetic interaction. Depending on the parameters set on the user interface 4 , for example, the flux density of a magnetic or electromagnetic field is set. In addition, biofeedback parameters that have been determined by means of the sensor device 8 can be used to set the field strength of the magnetic or electromagnetic field.
[0084] Control by means of biofeedback data by way of the sensor device 8 can take place in real time. This means that essentially at the same moment at which a change in the biofeedback data that is measured by the sensor device 8 takes place, after taking into account any computing time, adaptation of the electromagnetic interaction takes place by means of the device 6 for generating electromagnetic interaction. It is thus possible to react directly to changes in the state of the user.
[0085] For example heart rate variability (HRV), i.e. the variance in the heart beats or fluctuations in the heart rhythm that are determined by means of a finger sensor, can be used as a biofeedback signal. By means of the user interface 4 it is also possible, if so desired by a passenger or member of the crew, to select a program, for example a wellness program or a fitness program. In order to promote sleep or to reduce stress in the user, in addition acoustic signals can be made available by means of the acoustic playback unit 10 or optical signals can be provided by means of the display unit 12 . The acoustic signals can be relaxation-promoting frequency spectra, music or ultrasound, while the optical signals are for example displayed on the colour-light spectacles 12 or on a liquid crystal display 12 . In this arrangement the optical display unit 12 provides any colours from the entire colour spectrum, which colours are generated from the primary colours red, green and blue. These colours can have a direct effect on the open eyes of a user wearing the spectacles 12 . Connection of the following components: user interface 4 , device 6 for generating electromagnetic interaction, sensor device 8 , acoustic playback unit 10 and display unit 12 to the control unit can be by cable or by wireless technology, for example radio waves or Bluetooth.
[0086] If required, the control console 4 can be removable and can be integrated in a passenger seat, for example a front passenger seat. The entire device for regulating electromagnetic interaction 14 comprising the control device 2 , the user interface 4 , the sensor device 8 , the device 6 for generating electromagnetic interaction, the acoustic playback unit 10 and the display unit 12 can be accommodated in a passenger seat so that at least the components—control device 2 and device 6 for generating electromagnetic interaction—are not visible. Coupling the acoustic playback unit 10 for example with an entertainment system that is present as standard in an aircraft is possible. For each unit an additional weight of approximately 3 kg or less is to be calculated.
[0087] FIG. 2 shows a lateral section view of a seat 26 with a device 6 for generating electromagnetic interaction. The seat 26 comprises a seat frame 22 by means of which the seat is attached to the seat rail 24 in the floor, for example of an aircraft. The seat 26 comprises a backrest 16 , a seat surface 18 and a footrest 20 . Integrated in the backrest 16 , the seat surface 18 and the footrest 20 is a device 6 for generating electromagnetic interaction. This can for example be a coil or several coils. The coil can be designed in single-coil technology or as a magnetic-field mat.
[0088] In a design as a magnetic-field mat 6 a single coil extends in the mat 6 in a spiral pattern according to a complex mathematical model. This coil emits an even and homogeneous magnetic field that is independent of the stature and weight of a passenger. The design as a single coil that is arranged in a mat-shape makes it possible to inconspicuously integrate the device 6 for generating electromagnetic interaction in the backrest 16 , in the seat surface 18 or in the footrest 20 . By determining the size of the region which is backed by the coil 6 , the region of the electromagnetic interaction that acts on the passenger can be determined. In FIG. 2 the coil mat has been integrated in the backrest 16 , the seat surface 18 , and the footrest 20 . In other words, a passenger or a member of the crew seated in the seat 26 can receive whole-body treatment.
[0089] When seated, a passenger or member of the crew or some other user of the seat is accommodated by the accommodation region 28 . Due to the modular design of the device for regulating electromagnetic interaction 14 it is possible to retrofit said device to conventional passenger seats.
[0090] Depending on the requirement of the respective passengers, all the seats in an aircraft, or, for example, only seats of higher price categories such as first-class or business-class, can be equipped with the device for regulating electromagnetic interaction. When fitting out the seats of members of the crew, for example the cockpit crew or the cabin crew, the safety and well-being of the crew, for example of a pilot, is paramount. During a long-distance flight a pilot can use the seat 26 in order to recuperate better and faster, which improves flight safety.
[0091] However, it is also possible for particular regions of an aircraft, for example wellness regions, to be fitted with chairs 14 or seats 14 . If need be, these chairs 14 or seats 14 can be used by individual passengers, i.e. they can be used for a fee.
[0092] FIG. 3 shows a diagrammatic rear view of a seat with a device for generating electromagnetic interaction. The image shows a two-seat arrangement according to the present invention. The two seats of the seat arrangement shown are symmetrical in relation to the connection element 30 . For this reason, only one seat is described below. Corresponding statements apply to the symmetrically arranged seat. The device 6 for generating electromagnetic interaction, for example a magnetic-field mat in single-coil technology, is integrated in the backrest 16 , the seat surface 18 and the footrest 20 . In FIG. 3 the backrest 16 , the seat surface 18 and the footrest 20 have a magnetic-field mat of their own.
[0093] However, for easier installation and to achieve cost advantages it is also possible to use an individual mat which extends without interruption inside the backrest 16 , the seat surface 18 and the footrest 20 . The magnetic-field mats 6 are controlled by a control device 2 (not shown in FIG. 3 ). The backrest 16 , the seat surface 18 and the footrest 20 of the two seats are arranged on the shared seat frame 22 . Therefore, during installation it is not necessary to install two individual seats, but instead only a common seat arrangement. In this way the installation process can be accelerated.
[0094] FIG. 4 shows a device for generating electromagnetic interaction. The figure shows the magnetic-field mat 6 , which due to the single-coil technology used is flexible, easy to handle and rollable. This single-coil technology essentially achieves the homogeneity (evenness) of one coil.
[0095] FIG. 4 shows the magnetic mat 6 both in the rolled-out and in the rolled-in 32 form. The magnetic mat is connected to the control device 2 which controls and adapts to the requirements of a passenger the magnetic flux density or magnetic field strength generated by the coil of the magnetic mat 6 . Due to the flexibility of the magnetic mat 6 and its easy handling, the magnetic mat 6 can be produced in any desired size so that retrofitting it to already existing seats is facilitated. It is thus easily possible to retrofit the device to seats in trains, automobiles, aircraft, ships, coaches or trams, or other means of transport.
[0096] FIG. 5 shows an embodiment of a sensor device. In FIG. 5 the embodiment of a sensor device as a finger clip 8 is shown. The finger clip 8 measures, on a finger of a hand, for example deviations of the heart rhythm. As a result of this, biofeedback signals are generated, which are conveyed to the control device 2 . Based on these biofeedback signals, the control device 2 determines whether any increase or decrease in the treatment parameters, for example in the flux density or field strength of a coil, are necessary. This calculation can take place in real time. The biofeedback signal, for example the heart rhythm, is a measure that indicates the state of the patient and thus serves to control the therapy.
[0097] Possible treatment parameters are for example the pulse frequency of a pulsating electromagnetic field (ELF) or the signal form of said pulse frequency. Likewise, the necessary treatment duration can be determined. Typical values are: induction fields with flux densities ranging from 8 to 15 mT with a frequency of 10, 15 or 20 Hz with rectangular, triangular or sawtooth pulse or semi-triangular pulses for a duration of preferably 12 minutes, in particular 8-16 minutes.
[0098] FIG. 6 shows a passenger with an acoustic playback unit and a display unit. The display unit 12 is placed on the head of the passenger 34 in such a way that the colour spectra generated by the display unit 12 can have a direct effect on the open eyes. At the same time, by way of the acoustic playback unit, acoustic signals act on the passenger 34 , wherein the frequencies of said acoustic signals are matched to the magnetic fields and the light spectrum. In this arrangement the acoustic playback unit 10 is pulled over the head of the passenger in such a way that the frequencies generated by the sound component 10 can have an effect on the ears of the user 34 . The use of the optical display unit and of the acoustic playback unit 10 promotes the relaxation of the user, passenger or member of the crew during treatment with the magnetic field.
[0099] In addition it should be pointed out that “comprising” does not exclude other elements or steps, and “a” or “one” does not exclude a plural number. Furthermore, it should be pointed out that characteristics or steps which have been described with reference to one of the above embodiments can also be used in combination with other characteristics or steps of other embodiments described above. Reference characters in the claims are not to be interpreted as limitations.
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A seat with a device for generating electromagnetic interaction in an accommodation region that is equipped to accommodate an object. By electromagnetic interaction, an object can be influenced in such a way that, for example, fatigue that occurs during long-distance flights can be avoided. The device is used to prevent and reduce the occurrence of jet lag, reduce the danger of passengers suffering from thrombosis, and increase general well-being by promoting relaxation, sleep and stress reduction. The integration in cabin crew seats and/or cockpit seats can improve the performance of the crew of an aircraft on long-distance flights.
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PRIORITY CLAIM
[0001] In accordance with 37 C.F.R. 1.76, a claim of priority is included in an Application Data Sheet filed concurrently herewith. Accordingly, the present invention claims priority to U.S. Provisional Patent Application No. 62/232,021, entitled “ACCESS ASSEMBLY FOR ANTERIOR AND LATERAL SPINAL PROCEDURES”, filed Sep. 24, 2015. The contents of which the above referenced application is incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates generally to stabilization of adjacent bony structures of the spine; and more particularly, to an assembly and method for providing anterior and/or lateral access to the disc space of the vertebrae for providing stabilization to the bony structures thereof.
BACKGROUND INFORMATION
[0003] It is widely held that healing and/or structural correction is greatly facilitated when a bone is stabilized in the proper position. Various devices for stabilization of bone are well known and routinely practiced in the medical arts. For example, an abnormal spine can be stabilized using a substantially rigid or semi-rigid interconnecting means (rod or plate) and fastening means (screws, clamps, hooks, claws, anchors, or bolts). Multiple fasteners are placed into the spinal pedicle of each vertebra and linked by at least one interconnecting means. Once in place, these systems substantially immobilize the spine and promote bony fusion (arthrodesis).
[0004] With respect to the thoracic spine, it may be afflicted with a variety of ailments, some so severe as to require surgical intervention. A disc herniation may compress the spinal cord and/or nerve roots and cause pain, loss of function, and even complete paralysis of the legs with loss of bowel and bladder control. The correct treatment for such conditions is the removal of the offending discal tissue. However, this has proven both difficult and quite dangerous. When the discs of the thoracic spine are approached posteriorly (from behind), the spinal cord is in the way. To approach the same herniation anteriorly (from the front) requires the very formidable procedure of thoracotomy (cutting open the chest) and moving the heart and lungs out of the way.
[0005] Quite recently, surgeons have begun performing these procedures from a lateral approach to the spine (from the side) using fiber optic viewing instruments called thorascopes and numerous small surgical openings through the chest wall (portals) through which various surgical instruments, such as burrs, rongeurs and curettes, may be placed to remove these disc herniations while avoiding formal thoracotomy. Because the discs are very narrow in the thoracic spine and the surgeon is approaching the spine laterally, there is very little space in which to work as the disc is entered. Therefore, the amount of disc removal may be limited. Alternatively, the surgeon might remove the pedicle to gain access to the spinal canal, risking further weakening of the already diseased area.
[0006] For a variety of reasons, including the removal of disc material, the thoracic spine may sometimes become unstable (too much motion) at any given level. Historically, this has been treated by fusion, the joining together permanently of the unstable vertebrae via a bridge of bone so as to eliminate all motion at that location. Fusions about the thoracic spine have been performed either anteriorly or posteriorly, either procedure being a serious surgical undertaking.
[0007] Stability of the spine is required for fusion to Occur. For this reason, and for the purpose of correcting spinal deformity, it is often necessary to use hardware to rigidly internally fixate (stabilize) the spine. To date, the only benefit the use of the thorascope has provided in this regard is to allow the previous thoracotomy incision to be somewhat smaller.
[0008] Thus, the prior art includes numerous drawbacks which have not been entirely addressed. Traditionally, the surgical techniques for stabilization of bone required large incisions (upwards of 6 cm in length) and a considerable amount of muscle be cut and stripped away (retracted) from the bone for an “open” visualization of the bone and access thereto for the placement of the fasteners and instrument implantation. Although this so-called “open” surgical technique has successfully treated non-unions, instability, injuries and disease of the spine, it is not without disadvantages. Given the invasive nature of this technique, a lengthy healing time and considerable post-operative pain for the patient is common.
[0009] With respect to the human lumbar spine, the treatment of discal disease with neural compression has generally been from a posterior (from behind) approach. Lumbar discs are generally quite large, and it is only those protrusions occurring posteriorly which compress the neural elements, which are themselves posterior to the discs. These posterior approaches have included both true posterior approaches and posterolateral approaches to the discs. Further, such approaches have been made via open incisions or through percutaneous stab wounds. In the latter case, instruments are inserted through the stab wounds and monitored by the use of radiographic imaging or the use of an endoscopic viewing device. While it is possible to also decompress a posterior disc herniation in the lumbar spine from an anterior approach (from the front), doing so requires the removal of a very substantial portion or all of the disc material in the front and mid portions of the disc, thus leaving that disc and that spinal segment generally unstable. Therefore, such an anterior approach to the lumbar spine has been reserved for those instances where a fusion is to be performed in conjunction with, and following such a disc removal.
[0010] Fusion is generally induced with the application of bone or bone like substances between bones to induce bony bridging; such procedures have been performed outside the vertebral bodies and/or between the vertebral bodies, the latter being known as an interbody fusion. Such interbody fusions have been performed from posterior, posterolateral and anterior. Interbody fusion from the posterior approach, while still in use, has been associated with significant complications generally related to the fact that the delicate dural sac and the spine nerves cover the back of the disc space and are, thus, clearly at risk for damage with such an approach. The posterolateral approach has generally been utilized as a compliment to percutaneous discectomy and has consisted of pushing tiny fragments of morselized bone down through a tube and into the disc space.
[0011] In anterior interbody spinal fusion, the path of entry of the fusion material into the intervertebral space is performed from a straight anterior position. Such an anterior position is achieved in one of two ways. First, by a straight anterior approach which requires that the peritoneal cavity, which contains the intestines and other organs, be punctured twice, once through the front and once through the back on the way to the front of the spine; or secondly, by starting on the front of the abdomen off to one side and dissecting behind the peritoneal cavity on the way to the front of the spine. Regardless of which approach to the front of the spine is used, and apart from the obvious dangers related to the dense anatomy and vital structures in that area, there are at least two major problems specific to the anterior interbody fusion angle of implant insertion itself. First, generally at the L.sub.4 and L.sub.5 discs, the great iliac vessels bifurcate from the inferior vena cava and lie in close apposition to and covering that disc space, making fusion from the front both difficult and dangerous. Secondly, anterior fusions have generally been done by filling the disc space with bone or by drilling across the disc space and then filling those holes with shaped implants. As presently practiced, the preferred method of filling the disc space consists of placing a ring of allograft (bone not from the patient) femur into that disc space. An attempt to get good fill of the disc space places the sympathetic nerves along the sides of the disc at great risk. Alternatively, when the dowel technique is used, because of the short path from the front of the vertebrae to the back and because of the height of the disc as compared to the width of the spine, only a portion of the cylindrical implant or implants actually engage the vertebrae; thus compromising the support provided to the vertebrae and the area of contact provided for the fusion to occur.
[0012] There is, therefore, in regard to the lumbar spine, a need for a new method and apparatus for achieving interbody fusion which avoids the problems associated with all prior methods, and which have included, but are not limited to, nerve damage when performed posteriorly, or the need to mobilize the great iliac vessels when performed anteriorly. Further, the size of the implants is limited by the dural sac posteriorly, and the width of the spine and the delicate vital structures therewith associated anteriorly. Such a method and apparatus for interbody fusion should provide for optimal fill of the interspace without endangering the associated structures, and allow for the optimal area of contact between the implant or implants and the vertebrae to be fused. The method and apparatus should also provide controlled distraction of the bony structures, while also providing ease of access to the damaged area of the spine while minimizing risk to the patient.
SUMMARY OF THE INVENTION
[0013] Briefly, the present invention is directed to methods and instrumentation for performing surgery on the spine along its lateral aspect (side), and generally by a lateral, anterior or an anterolateral surgical approach, such that the instruments enter the body from an approach that is other than posterior and make contact with the spine along its lateral aspect. The present invention provides for the entire surgical procedure to be performed through a relatively small incision or puncture which may be performed in either the thoracic or lumbar spine.
[0014] In the preferred embodiment, the access assembly of the present invention comprises a needle assemble including an elongated handle, the needle assembly having a removable needle member for insertion of a guide wire and a first stage dilator that forms an outer surface of the needle cannula. In at least one embodiment, the first stage dilator feature of the needle assembly may also be utilized for providing additional controlled dilation of the tissue by acting as a guide for additional stages of dilators. A guide wire may be provided for insertion into the disc space through the lumen of the needle assembly with the assistance of x-rays, thorascope, image intensifier, direct vision or the like. For example, for surgery in the thoracic spine, a small incision in the chest cavity of the patient is made from a lateral approach to the thoracic spine. For surgery in the lumbar spine, a small incision may be made in the abdominal wall of the patient. Once positioned, the guide wire extends between the disc space to outside of the patient to provide a guideway for surgical tools and implants. The needle assembly includes an inner needle member and a cannula which are secured together with the elongated handle member through a split shoulder connection which allows an anvil area on the distal end of the needle member suitable for striking with a mallet or the like. The elongated handle includes a U-notch and a rotatable portion for retaining the needle and the cannula in an assembled arrangement. The first stage dilator includes an inner bore sized for cooperation with the outer surface of the cannula member and is preferably integrally formed thereto. The second stage dilator includes an inner bore sized to cooperate with the outer surface of the first stage dilator. In some embodiments, third and fourth stage dilators may be provided. In this manner, each successive dilator acts as a guideway for the next larger dilator.
[0015] Once the largest desired dilator tube is in place within the patient, the cannula and guide wire may be removed, providing an access tunnel to the disc space. The inner diameter of the outer dilator, e.g. tunnel, is provided with sufficient diameter for disc modification or removal, as well as the placement of spacers, bone fragments, implants and the like to be passed therethrough to the disc space. In at least one embodiment, the components of the system are constructed to either be constructed from electrically conductive materials or include electrically conductive pathways for use with neurophysiological monitoring equipment. Once the operation is completed, rotation and/or pulling on the dilator releases the dilator tube for removal from the patient.
[0016] Accordingly, it is an objective of the present invention to provide a device and method for performing surgery on the thoracic spine through the chest cavity from a lateral approach to the spine.
[0017] It is a further objective of the present invention to provide a device and method for performing a thoracic discectomy, an interbody fusion, and rigid internal fixation of the spine through the chest cavity from a lateral approach as a single integrated procedure.
[0018] It is yet a further objective of the present invention to provide a device and method for performing a lumbar fusion from the lateral aspect of the spine.
[0019] It is another objective of the present invention to provide a method and device for performing a lumbar fusion and spinal canal decompression from the lateral aspect of the spine.
[0020] It is yet another objective of the present invention to provide a device and method for performing a lumbar fusion, decompressive discectomy, and a rigid internal fixation of the spine as a single integrated surgical procedure.
[0021] It is still yet another objective of the present invention to provide a device and method to achieve discectomy, fusion and interbody stabilization of the lumbar without the need to mobilize the great iliac vessels from the front of the vertebral bodies.
[0022] It is still yet another objective of the present invention to provide a device for performing surgery on the spine that includes a needle assembly having a removable handle for locating the proper position related to the bony structure, whereby the handle may be removed for dilation of the entry path providing a tunnel to the surgical site.
[0023] It is still yet another objective of the present invention to provide a device for performing surgery on the spine that includes an integrally formed first stage dilator formed onto the outer surface of a needle cannula.
[0024] Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0025] FIG. 1 is a plan view illustrating one embodiment of the present invention;
[0026] FIG. 2 is a partial plan view of the embodiment shown in FIG. 1 illustrating the first end thereof;
[0027] FIG. 3 is a plan view of one embodiment of the access assembly of the present invention, illustrated with a second stage dilator in place;
[0028] FIG. 4 is an exploded plan view of one embodiment of the access assembly of the present invention;
[0029] FIG. 5 is a partial exploded plan view illustrating the first end of the handle member and the second end of the needle member of the access assembly;
[0030] FIG. 6 is a partial view of the first end of one embodiment of the access assembly of the present invention;
[0031] FIG. 7 is a partial orthographic view of the first end of the handle assembly;
[0032] FIG. 8 is a partial orthographic view of the first end of the handle assembly illustrating the locking groove positioned in the unlocked position;
[0033] FIG. 9 is a partial orthographic view of the needle assembly illustrating the locking assembly without the handle assembly; and
[0034] FIG. 10 is a partial perspective view of the first end of the handle assembly illustrated attaching the needle assembly together.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated.
[0036] Referring generally to FIGS. 1-10 , an access assembly constructed and arranged for anterior, lateral or anterolateral spinal procedures is illustrated. The present invention provides for the entire surgical procedure to be performed through a relatively small perforation or incision, and may be performed in either the thoracic or lumbar spine. In the preferred embodiment, the access assembly ( 10 ) comprises a needle assembly ( 12 ), a handle assembly ( 14 ), and at least one dilator tube ( 16 ). Some embodiments additionally include a guide wire ( 18 ). The needle assembly ( 12 ) is provided for initial insertion into the disc space through a small incision in the patient with the assistance of x-rays, thorascope, image intensifier, direct vision or the like. For example, for surgery in the thoracic spine, a small incision or perforation is made in the chest cavity of the patient from a lateral approach to the thoracic spine. For surgery in the lumbar spine, a small incision or perforation may be made in the abdominal wall of the patient. The first end ( 22 ) of the needle assembly ( 12 ) may be inserted with the assistance of the handle assembly ( 14 ), which connects the needle member ( 24 ) within the lumen ( 81 ) of the cannula ( 26 ), having the point ( 28 ) of the needle member ( 24 ) extending beyond the end point of the first end ( 84 ) of the cannula ( 26 ), and provides directional control of the needle assembly ( 12 ). In the preferred embodiment, the handle assembly ( 14 ) is oriented at a right angle with respect to the needle assembly to provide the surgeon with an angular reference to the trajectory of the needle assembly ( 12 ). The needle member ( 24 ) includes a point end ( 28 ), a central portion ( 90 ), and a second end ( 88 ). An outer diameter of the central portion being sized to fit snugly through the lumen ( 81 ) of the cannula ( 26 ). The point ( 28 ) of the needle member ( 24 ) may include a particular shape that aids in the insertion such as, but not limited to, a conical point, trocar, spherical or blunt. Once positioned, the needle assembly ( 12 ) extends between the disc space to outside of the patient to provide a guide-way for the guide wire ( 18 ), as well as the dilator tube(s). In operation, the needle member ( 24 ) is separated from the cannula ( 26 ) by rotating a clamp portion ( 30 ) of the handle assembly ( 14 ) to release the first clamp ring ( 32 ) of the needle member from the second clamp ring ( 34 ) at the second end ( 86 ) of the cannula. The needle may then be removed from the cannula, leaving a tunnel to the disc space. A guide wire ( 18 ) or the like may then be placed through the cannula ( 26 ) into the disc space. The guide wire ( 18 ) includes a first end ( 63 ), a second end ( 64 ) and a center portion ( 66 ). The first end ( 63 ) is preferably spherical in shape, but may be tapered, pointed, blunt, trocar or any other desirable shape. The second end of the guide wire ( 18 ) generally includes a blunt square cut. The guide wire ( 18 ) is preferably constructed from a biocompatible metal material, such as spring tempered stainless steel or nitinol. However, it should be noted that any material having sufficient rigidity to act as a guideway for the tools, implants and the like may be utilized without departing from the scope of the invention. Dilator tube(s) may be placed over the outer diameter of the cannula ( 26 ) either before insertion or after. Thereafter, removal of the cannula ( 26 ), along with inner dilator tubes, provides an access tunnel to the disc space, while the guide wire ( 18 ) provides a guide surface to the disc space for transfer of tools, implants and the like. The tunnel is provided with sufficient diameter for disc modification or removal as well as the placement of spacers, bone fragments, implants and the like to be passed therethrough to the disc space.
[0037] The first dilator tube ( 68 ) is generally an elongated tubular member having a first end ( 70 ), a central portion ( 74 ) and a second end ( 72 ). Extending through the central portion ( 74 ) of the dilator tube is a central aperture ( 76 ) sized for cooperation with the outer surface ( 78 ) of the center portion ( 80 ) of the cannula ( 26 ). The second dilator tube ( 16 ) is generally an elongated tubular member having a first end ( 36 ), a central portion ( 40 ) and a second end ( 38 ). Extending through a central portion of the dilator tube(s) is a central aperture ( 37 ) sized for cooperation with the outer surface of the central portion ( 74 ) of the first dilator tube ( 68 ). Any number of successive dilator tubes may be provided without departing from the scope of the invention. The first end ( 36 ), ( 70 ) of the dilator tubes ( 16 ), ( 68 ) preferably includes a tapered or rounded first end ( 36 ), ( 70 ) for ease of insertion into the tissue leading to the disc space. In a most preferred embodiment, the tapered first end ( 36 ), ( 70 ) includes a rounded shape. However, it should be noted that other shapes may be utilized for the rounded end so long as they provide a smooth transition from the outer diameter of the guide wire cannula to the outer diameter of the dilator. Such shapes may include, but should not be limited to spherical, bullet, pyramid or suitable combinations thereof. The first dilator tube ( 68 ) is preferably secured directly about the outer surface of the cannula ( 26 ), while each successive dilator tube is constructed and arranged to fit snugly about the outer diameter of the prior dilator tube. The outer surface ( 60 ) of each respective dilator tube ( 16 ) is preferably round to act as a guide surface for the next successive dilator tube. However, it should be noted that other matched shapes may be utilized without departing from the scope of the invention. Such matched shapes may include, but should not be limited to ovals, polygons and the like. It should also be noted that in at least one embodiment, the components of the system are constructed to either be constructed from electrically conductive materials or include electrically conductive pathways for use with neurophysiological monitoring equipment ( 82 ) as is known in the art.
[0038] Referring to FIGS. 2, 8-10 , assembly of the needle and cannula to the handle assembly is illustrated. The handle assembly ( 14 ) includes a clamp portion ( 30 ) and a rod portion ( 44 ). In the preferred embodiment, the rod portion is provided with male threads ( 46 ) while the clamp portion is provided with female threads ( 48 ) ( FIG. 4 ) which interact to allow the clamp portion to be moved along the end portion of the rod member. However, it should be noted the male and female threads could be reversed without departing from the scope of the invention. It should also be noted that mechanical or electrical means could be provided to provide a clamping force to the needle assembly without departing from the scope of the invention. The clamp portion ( 30 ) includes a groove ( 50 ) having a pair of generally flat opposing side surfaces ( 52 ) spaced a predetermined distance apart and extending along the length of the groove ( 50 ). The end of the rod portion likewise includes an indention ( 53 ). The groove and the indention cooperate with the first and second clamping rings ( 32 ), ( 34 ) to secure the needle member ( 24 ) within the cannula ( 26 ) by using the threads to force the distal end of the rod against the groove of the clamp portion. The second end ( 54 ) of the needle member ( 24 ) is provided with an anvil surface ( 56 ) suitable for striking with a mallet or the like. A gripping surface ( 58 ) is also provided for grasping and/or rotation of the needle member.
[0039] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each publication was specifically and individually indicated to be incorporated by reference.
[0040] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention, and the invention is not to be considered limited to what is shown and described in the specification.
[0041] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary, and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
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The present invention is directed to methods and instrumentation for performing surgery on the spine along its lateral aspect (side) and generally by a lateral, anterior or an anterolateral surgical approach, such that the instruments enter the body from an approach that is other than posterior and make contact with the spine along its lateral aspect. The present invention provides for the entire surgical procedure to be performed through a relatively small incision and may be performed in either the thoracic or lumbar spine.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119(a) to EP 05 003 011.3, filed Feb. 12, 2005, the entire contents of which is hereby incorporated by reference.
TECHNICAL FIELD
[0002] The application relates to a method for influencing the signal shape of an output signal of a radio-frequency (RF) power resonance amplifier.
BACKGROUND
[0003] For RF power generators that operate in pulsed operation, the switching-on edge of the RF power, i.e. the edge of the envelope of the output signal of the RF power generator, is in general an important criterion. There are also applications in which it is useful to interrupt the pulses within a minimum time. One example of such an application is the operation of opto-acoustic Q-switches in pulsed inscription lasers. In this case, for example, the 27 MHz RF power of the RF power generator is supposed to drop at the pulse end within maximally 100 ns, i.e., 2.5 oscillating periods from 50 W to less than 50 mW. One problem with the use of a resonance amplifier consists in that two quality features depend on the quality of the output oscillating circuit. The spectral purity of the output signal increases with increasing quality as does the dying down period upon switching off.
[0004] DE 199 29 332 A1 discloses a driver for a Q-switch or other acousto-optical components for laser applications. The driver includes a radio frequency oscillator and an amplifier fed with the signal of the radio frequency oscillator for driving the acousto-optical component, having a bandwidth which exceeds several times the frequency of the radio frequency oscillator, and a control input for setting the amplification of the amplifier to control the influence on a laser beam by the acousto-optical component. This approach uses an amplifier with a very large bandwidth that controls the higher frequency portions contained in steep signal edges to a sufficient degree.
SUMMARY
[0005] A method and a device for generating output signals of a pulsed RF power resonance amplifier is described. The output signals have steep edges.
[0006] An output oscillating circuit of the RF power resonance amplifier is driven with a driving signal that differs from a basic signal of an oscillator that feeds the RF power resonance amplifier at points in time that are predeterminable, that is either predetermined or can be predetermined. The driving signal can differ from the basic signal, in particular, in terms of phase position and/or frequency and/or pulse-duty factor. Preferably, at least one of these variables differs by at least 5% from the corresponding variable of the basic signal during normal operation. Normal operation is the operation at the basic frequency without generating a driving signal.
[0007] These actions accelerate excitation and dying down of oscillations of the output oscillating circuit compared to natural exponential excitation and dying down of oscillations. Thus, the envelope of the output signal follows the signal shape of the modulation signal more precisely than with a resonance amplifier without driving signal. Compared to the broadband amplifier of DE 199 29 332 A1, the envelope obtained is of similar good quality, only the technology is greatly facilitated and less expensive. If the modulation signal is a rectangular signal, i.e., a pulsed signal, the envelope of the output signal has steep edges. The driving signal may, for example, be generated by deliberately extending the on-time upon initial switching-on of the switching element/s of the RF power resonance amplifier or by supplying the output oscillating circuit with a higher voltage or power than during normal operation through use of an additional switch.
[0008] If several oscillating circuits are provided in the RF power resonance amplifier, it is possible to drive several oscillating circuits with the driving signal that differs from the basic signal.
[0009] The method can, in particular, accelerate the dying down of a pulsed basic signal. Driving with a driving signal that differs from the basic signal at least partially eliminates the energy stored in the output oscillating circuit, which considerably shortens the dying down process. In this manner, the duration of the dying down process can be reduced with an output oscillating circuit with high quality. For this reason, an output oscillating circuit with high quality and good filtering effect can be used thereby generating an output signal having a large spectral purity.
[0010] In one implementation, the output oscillating circuit may be driven with a driving signal that considerably differs from the basic signal for a length of time that is or can be predetermined. This particularly optimizes rapid dying down.
[0011] In another implementation, the point in time and length of time may be selected to obtain an envelope of the output signal having steep edges. This can be achieved, in particular, by generating the driving signal in dependence on the modulation signal. The modulation signal generates, for example, a pulsed output signal of the RF power resonance amplifier. The start and end of a pulse of the modulation signal generally may require a steep edge of the envelope of the output signal. For this reason, each pulse of the modulation signal may be followed by excitation of the output oscillating circuit with one or more intentional “wrong” cycles.
[0012] The driving signal can be generated in one manner by changing the basic signal, in particular, the frequency, phase, and/or pulse-duty ratio of the basic signal. Through excitation of the output oscillating circuit with the basic signal, i.e., with the basic frequency and the basic phase, the output oscillating circuit is operated in resonance. When the output oscillating circuit is excited with a different signal, oscillation of the output oscillating circuit is decelerated.
[0013] In another implementation, the control signal may be generated by a separate function generator that drives the output oscillating circuit either directly or by interposition of a switch, in particular, a transistor. A function generator can generate almost any driving signal. The function generator can also drive one or more switching elements (for example, amplifying transistors) of the RF power resonance amplifier. A function generator disposed in this manner can generate a deceleration pulse when the driver stage of the RF power resonance amplifier stops delivering signals, i.e., when the modulation signal pulse pauses.
[0014] A coupling circuit may be disposed between the driver stage and the switching element/s. The coupling circuit may be designed as oscillating circuit. The oscillating circuit is usually selected to have its resonance frequency in the range of the basic frequency to drive the switching elements of the RF power resonance amplifier with sufficient current and voltage and minimum energy loss. The driving signal, which differs from the basic signal, can be generated with a coupling circuit of this type by tuning the coupling circuit of the RF power resonance amplifier to which the basic signal is supplied, to a frequency other than the basic frequency f T , i.e., to f 0 =f T +Δ. The driver stage and hence the coupling circuit therefore operate consistently at the frequency f T as long as a pulse of the modulation signal is applied. As soon as it stops, the coupling circuit dies down with several dying down periods of the frequency f 0 . Driving of the switching element and the output oscillating circuit with this frequency, which is phase-shifted to the basic frequency f T , produces the changed driving signal and thereby one or more deceleration pulses.
[0015] Experiments have shown that good results are obtained if f 0 differs by about 5% to about 20% from f T , in particular, if f 0 is about 5% to about 20% less than f T . If f 0 is approximately 10% less than f T , after five periods at a frequency f 0 , the amplitudes of an oscillation at f 0 and an imaginary continuing f T oscillation are in opposite phase, and the output signal shows no considerable oscillation any more (that is, less than about 0.1% from the output signal during normal operation).
[0016] A deceleration pulse can be generated as the driving signal and the output oscillating circuit is driven by the deceleration pulse. The energy stored in the output oscillating circuit can be eliminated by deceleration pulses that may be superposed to the basic signal or that can drive the output oscillating circuit alternatively to the basic signal, thereby considerably reducing the dying down process. The tailored deceleration pulses can be generated by a separate power transistor or through suitable driving of the existing active elements, in particular, one or more amplifier transistors. This driving may again be generated either by a separate function generator circuit or, in the simplest case, by the existing driver stage due to a frequency jump of the driver stage when the basic signal is switched off at the start of the modulation signal pulse pause.
[0017] In one general aspect, a method for influencing the signal shape of an output signal of an RF power resonance amplifier includes amplifying a basic signal of a basic frequency, modulating the basic signal with a modulation signal, tuning an output oscillating circuit of the RF power resonance amplifier to a frequency in the range of the basic frequency, and exciting the output oscillating circuit with the basic signal during normal operation. The method further includes driving the output oscillating circuit with a driving signal that differs from the basic signal at points in time to produce the output signal.
[0018] Implementations may include one or more of the following features. For example, modulating the basic signal may include pulsing the basic signal.
[0019] Driving the output oscillating circuit with the driving signal may include driving the output oscillating circuit with the driving signal at predetermined points in time. Driving the output oscillating circuit with the driving signal may include driving for a predetermined length of time. The length of time may be selected to produce an envelope of the output signal that has a steep edge at least at the falling edge. The point in time may be selected to produce an envelope of the output signal that has a steep edge at least at the falling edge.
[0020] The method may include generating the driving signal in dependence on the modulation signal. The method may further include generating the driving signal by changing the basic signal. Changing the basic signal may include changing one or more of the frequency, the phase, and the pulse-duty ratio of the basic signal. The method may include generating the driving signal by a separate function generator that drives the output oscillating circuit. The separate function generator may drive the output oscillating circuit directly. The separate function generator may drive the output oscillating circuit through an interposition of a switch. The switch may include a transistor.
[0021] The method may include tuning a coupling circuit of the RF power resonance amplifier to which the basic signal is supplied to a frequency differing from the basic frequency. The method may include generating a deceleration pulse as the driving signal, wherein the output oscillating circuit is driven by the deceleration pulse.
[0022] In another general aspect, an RF excitation arrangement includes an RF power resonance amplifier that includes a driver stage amplifying a basic signal, at least one active element, and at least one output oscillating circuit disposed downstream of the at least one active element. The output oscillating circuit is tuned to a frequency in the range of the basic frequency of the basic signal. The RF excitation arrangement includes a modulation signal generator that generates a modulation signal for modulating the basic signal. The RF excitation arrangement includes a driving signal unit that generates a driving signal, that differs from the basic signal, and that is input to the output oscillating circuit.
[0023] The output oscillating circuit can be generally designed as a resonance circuit that is substantially tuned to a basic frequency. The active elements may be amplifier stages or switching elements, such as, for example, one or more transistors. For example, the RF power resonance amplifier may be a class E amplifier that generally has one single transistor that is operated in switched operation. However, it is also feasible to operate an RF power resonance amplifier with several transistors and to operate the transistor/s also in the amplifying operation. An RF power resonance amplifier includes one or more resonance circuits to ensure that the basic wave (basic frequency of the basic signal) is transferred to a load (the active, in particular, switching elements (amplifier transistors) still generate a plurality of harmonic waves). The resonance circuit also ensures that the active elements are operated with minimum loss. Towards this end, the output oscillating circuit may be slightly mistuned relative to the basic frequency. The RF excitation arrangement has high quality, high spectral purity, good filtering effect.
[0024] The driving signal can be generated in dependence on the modulation signal when the driving signal unit is connected to the modulation signal generator.
[0025] A control signal in the form of one or more decelerating pulses can be generated in a particularly easy manner when the driving signal unit includes at least one switch, such as, for example, a power transistor.
[0026] The driving signal shape can be influenced when the driving signal unit includes at least one function generator. The function generator may be connected directly to the amplifier transistor or through one or more transistors directly to the output oscillating circuit of the RF power resonance amplifier. It is also possible to use several function generators.
[0027] The at least one active element of the RF power resonance amplifier may be designed for operation up to a frequency in the range of the basic frequency. However, the at least one active element need not be designed for higher frequencies. For this reason, active elements can be used that are less expensive than those used in prior amplifiers.
[0028] A driving signal can be generated with simple technical measures by connecting a coupling circuit between the driver stage and the at least one active element of the RF power resonance amplifier that is tuned to a frequency that is different from the basic frequency, to form a driving signal unit. Generation of a decelerating signal is can be accomplished, as explained above.
[0029] With particular advantage, the RF excitation arrangement and the method can be used for operating a Q-switch, for example, an opto-acoustic Q-switch. Pulsed radio frequency signals having extremely short dying down times at each pulse end are required for driving a Q-switch of this type.
[0030] Further features and advantages can be extracted from the following description, from the figures, and from the claims. The individual features may be realized individually or collectively in arbitrary combination.
DESCRIPTION OF DRAWINGS
[0031] FIG. 1 a is a schematic diagram of a first implementation of an RF excitation arrangement;
[0032] FIG. 1 b is a schematic diagram of a second implementation of an RF excitation arrangement with a driving signal unit driving a switching element of the RF power resonance amplifier;
[0033] FIG. 1 c is a schematic diagram of a third implementation of an RF excitation arrangement with driving signal unit disposed between a driver stage and a switching element;
[0034] FIG. 1 d is a schematic diagram of a fourth implementation of an RF excitation arrangement with a driving signal unit disposed in a driver stage;
[0035] FIG. 1 e is a schematic diagram of a fifth implementation of an RF excitation arrangement with a driving signal unit disposed in an oscillator;
[0036] FIG. 2 a is a graph of a modulation signal from a modulation signal generator;
[0037] FIG. 2 b is a graph of a basic signal that is amplitude-modulated with the modulation signal of FIG. 2 a , and is followed by a driving signal;
[0038] FIG. 2 c is a graph of an RF output signal as generated without a driving signal;
[0039] FIG. 2 d is a graph of the basic signal that is amplitude-modulated with the modulation signal with driving signal; and
[0040] FIG. 2 e is a graph of an RF output signal as produced with driving signal.
[0041] Like reference symbols in the various drawings may indicate like elements.
DETAILED DESCRIPTION
[0042] FIG. 1 a shows a radio frequency (RF) excitation arrangement with an RF power resonance amplifier 1 that includes a driver stage 2 driving a switching element 4 . The driver stage 2 is connected to an oscillator 14 . The oscillator 14 provides a high-frequency signal (a basic signal) that is amplified by the driver stage 2 , which thereby drives the switching element 4 . The driver stage 2 is driven with a modulation signal from a modulation signal generator 5 . The modulation signal has a frequency that is lower than the frequency of the basic signal. The basic signal has, for example, a basic frequency f T =27.12 MHz and the modulation signal has, for example, a modulation frequency f 2 =100 kHz. The modulation signal may be pulsed, in particular, with a rectangular signal, and can have any pulse-duty ratio.
[0043] An amplified RF signal is present at the output of an output oscillating circuit 6 and hence at the output of the RF power resonance amplifier 1 . This RF signal is an amplified version of the basic signal, which is modulated with the modulation signal from the modulation signal generator 5 . The output oscillating circuit 6 is tuned to a frequency in the range of the basic frequency of the basic signal. A rectangular signal with a predetermined pulse/pause ratio is generally used as the modulation signal. This means that the output signal of the RF power resonance amplifier 1 is a pulsed RF signal. During a pulse pause of the modulation signal, the output signal should quickly die down. If the output oscillating circuit 6 is temporarily not excited by the driver stage 2 due to a modulation signal pulse pause, the output oscillating circuit 6 continues to oscillate. To minimize this further oscillation or dying down oscillation, the output oscillating circuit 6 is driven by a driving signal that differs from the basic signal. There are several possibilities to accomplish this. In FIG. 1 a , the RF excitation arrangement includes a driving signal unit 7 a that includes two switches 8 , 9 designed as transistors that are each driven by a function generator 10 , 11 . To ensure that the driving signal is transferred to the output oscillating circuit 6 at the right time and with the correct length, the function generators 10 , 11 , and hence the driving signal unit 7 a , are connected to the modulation signal generator 5 to enable generation of the driving signal in dependence on the modulation signal. The output power of the RF power resonance amplifier 1 can be adjusted using the voltage supply U B . The driving signal unit 7 a also can be supplied by U B , as shown in FIG. 1 a , or it can be supplied by an independent voltage or a current source.
[0044] An impedance adjustment member 12 may be connected downstream of the RF power resonance amplifier 1 . The impedance adjustment member 12 is thereby disposed between the output oscillating circuit 6 and a load 13 that may be designed as Q-switch and may be operated by the output signal. The impedance adjustment member 12 and the load 13 also may be able to oscillate and hence have a resonance frequency. A quartz Q-switch, for example, has a resonance frequency. The dying down behavior of the output oscillating circuit 6 can thereby depend on the downstream elements. If, for example, the resonance frequencies of the impedance adjustment member 12 and/or the load 13 are known, they can be taken into consideration for generating the driving signal in such a manner that the dying down of the output oscillating circuit 6 connected downstream of the switching element 4 is accelerated due to lack of excitation by the basic signal.
[0045] The corresponding components are designated with the same reference numerals below. In contrast to FIG. 1 a , a driving signal unit 7 b of FIG. 1 b is connected to the switching element 4 . The RF excitation arrangement of FIG. 1 b also includes an external direct current supply 15 .
[0046] Referring to FIG. 1 c , the driving signal is generated by a driving signal unit 7 c that is designed as a coupling circuit by tuning the coupling circuit to a frequency f 0 =f T +Δ that is different from the basic frequency f T . For this reason, the driver stage 2 and hence also the coupling circuit (the driving signal unit 7 c ) are consistently operated at a frequency f T as long as a positive level of the modulation signal is applied. Upon termination of the modulation signal, the coupling circuit dies down with a few dying down periods of the frequency f 0 . The driving signal is generated through driving the switching element 4 and the output oscillating circuit 6 at the frequency f 0 , which is phase-shifted compared to the basic frequency f T .
[0047] Referring to FIG. 1 d , the driver stage 2 is designed as a driving signal unit or the driver stage 2 includes a driving signal unit 7 d . The driving signal is generated by changing the basic signal f T in the driver stage 2 or in the driving signal unit 7 d.
[0048] Another way to generate the driving signal is shown in FIG. 1 e . In FIG. 1 e , the oscillator 14 represents a driving signal unit or the oscillator 14 includes a driving signal unit 7 e . Thus, the driving signal is generated by changing the basic signal in the oscillator 14 or in the driving signal unit 7 e contained within the oscillator 14 . The oscillator 14 may therefore consist, for example, of a quartz oscillator or a similar frequency-stable oscillating structure and an external logic, for example, a logic component that can be programmed (such as a complex programmable logic device or a CPLD). In this case, the modulation signal also would be associated with the oscillator 14 .
[0049] FIGS. 1 a - 1 e show the elements 5 , 7 a , 7 b , 12 , 14 , 15 outside of the RF power resonance amplifier 1 . In another implementation, these elements may, be a part of or within the RF power resonance amplifier 1 .
[0050] FIGS. 2 a through 2 e show schematic views of signals that need not be to scale but better clarify the principle of function. FIG. 2 a shows, for example, a graph of a modulation signal 20 that can be generated by the modulation signal generator 5 . As shown in FIG. 2 a , the modulation signal 20 is a rectangular signal. The signal shape of the modulation signal 20 represents the desired signal shape of the envelope of the output signal of the output oscillating circuit 6 .
[0051] FIG. 2 b shows a graph of the basic signal from the oscillator 14 , which is amplitude-modulated with the modulation signal 20 . This means that the output oscillating circuit 6 is fed with a radio frequency input signal as long as the modulation signal 20 has a positive signal level.
[0052] FIG. 2 c shows a graph of an output signal 22 of the output oscillating circuit 6 without applying a driving signal that is different from the basic signal. This graph also shows an envelope 23 of the output signal 22 . The envelope 23 only gradually follows the rising edge 24 of the modulation signal 20 in the region 25 as long as the output oscillating circuit 6 oscillates. After a certain time, the envelope 23 reproduces the modulation signal 20 with relatively good precision in the region 26 . After a falling edge 27 of the modulation signal 20 , the output oscillating circuit 6 gradually dies down, which results in a flat edge 28 of the output signal 22 .
[0053] FIG. 2 d shows a graph of the basic signal 29 , which is amplitude-modulated with the modulation signal, followed by the driving signal 30 from the driving signal unit (such as 7 a , 7 b , 7 c , 7 d , 7 e ). As shown, the signal 29 does not abruptly stop after the falling edge 27 of the modulation signal 20 , but a driving signal 30 is generated that has two deceleration pulses 31 , 32 . The output oscillating circuit 6 is driven by the driving signal 30 with the result that the output oscillating circuit 6 dies down more quickly so that the envelope 33 of an output signal 34 of the output oscillating circuit 6 , as shown in FIG. 2 e , has a steep edge 35 . In particular, a “steep edge” is an edge in which an amplitude of the slope of the output signal 34 is steeper than approximately −A/(5×T T ), where T T is a period of the basic frequency f T , and A is an amplitude of the output signal 34 taken at the falling edge 27 of the modulation signal 20 . This approximation is a rough linear approximation of a slope that likely follows a non-linear path. In one implementation, the slope of the output signal 34 can be steeper than approximately −A/(2.5×T T ).
[0054] Other implementations are within the scope of the following claims.
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A method is performed for influencing the signal shape of an output signal of an RF power resonance amplifier and an RF excitation arrangement including an RF power resonance amplifier. A basic signal of a basic frequency is amplified and modulated with a modulation signal, and an output oscillating circuit of the RF power resonance amplifier is tuned to a frequency in the range of the basic frequency, and is excited with the basic signal during normal operation. At times that are or can be predetermined, the output oscillating circuit is driven with a driving signal that differs from the basic signal, for a time period that is or can be predetermined. This reduces the dying down time of the output oscillating circuit and increases the steepness of the output signal edges.
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BACKGROUND OF THE INVENTION
The subject matter disclosed herein relates to a turbine, such as a gas turbine.
A gas turbine is designed to operate at a peak load or base load. The turbine has a compressor, to take in a fluid and compress the fluid, a combustion section to combust a fuel to heat the fluid, and a turbine section to generate power with the heated fluid. When the turbine operates at peak load, the turbine operates at a predetermined combustion level to drive a turbine section. However, when the turbine is operated off-peak, or at part-load, the efficiency of the turbine decreases.
BRIEF DESCRIPTION OF THE INVENTION
According to one aspect of the invention, a turbine includes a compressor to intake a fluid and compress the fluid, a combustion section to combust a fuel to generate heated fluid by heating the fluid from the compressor, a turbine section to convert the heated fluid to work, an exhaust to output the heated fluid from the turbine section, and a bypass circuit to generate a bypass flow by taking in compressed fluid from the compressor, to heat the bypass flow with the heated fluid from the exhaust, and to output the heated bypass flow to the turbine section.
According to another aspect of the invention, a power generation system comprises: a turbine having a compressor to take in and compress a fluid, a combustion section to heat the fluid from the compressor, a turbine section to drive a shaft with the heated fluid from the combustion section, an exhaust section to eject the heated fluid from the turbine section, and bypass circuit to generate a bypass flow by taking in a portion of the compressed fluid from the compressor and selectively directing the bypass flow to the turbine section and the exhaust section; and a turbine control unit to determine an operating mode of the turbine among a peak mode and a part-load mode, and to control the bypass circuit to transmit the bypass flow to one of the turbine section and the exhaust section according to the determined operating mode.
According to yet another aspect of the invention, a method to control part-load performance of a turbine comprises generating a bypass flow in a turbine by removing a portion of a compressed fluid from a compressor of the turbine; determining an operating load of the turbine; transmitting the bypass flow to a turbine section of the turbine; and selectively heating the bypass flow according to the determined operating load of the turbine.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWING
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 illustrates a turbine according to one aspect of the invention.
FIG. 2 illustrates the turbine and a turbine control unit.
FIG. 3 illustrates a turbine section according to an embodiment of the invention.
FIG. 4 is a flow chart to illustrate a control operation of the turbine.
FIG. 5 illustrates a turbine according to an embodiment of the invention.
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a turbine 1 according to an embodiment of the invention. The turbine 1 includes an intake section, or compressor, 10 , a combustion section 20 , a turbine section 30 , and an exhaust section 40 . The compressor 10 intakes a fluid and compress the fluid before transmitting the fluid to the combustion section 20 . According to the present embodiment, the fluid is air, and the compressor 10 comprises a plurality of stages, each stage including an annular ring of blades rotating about a shaft and a subsequent annular ring of vanes.
The combustion section 20 receives the compressed air and heats the compressed air by combusting fuel F in a combustion chamber 21 . The heated compressed air is transmitted to the turbine section 30 , where it drives a rotor including buckets rotating about a shaft, and the rotating shaft generates power.
The exhaust section 40 receives the heated air from the turbine 30 and outputs the heated air.
In the present embodiment of the invention, the turbine 1 also includes a bypass circuit 50 . The bypass circuit 50 includes a conduit 52 to transmit air from the compressor 10 to a valve 51 , a conduit 53 to transmit air to the turbine from the valve 51 , and a conduit 54 to transmit air to the exhaust section 40 from the valve 51 . In addition, a conduit 55 transmits air from the exhaust section 40 to the turbine section 30 .
The exhaust section 40 includes a heat exchanger 41 to heat the air from the conduit 54 . The heated air is then transmitted via the conduit 55 to the turbine section 30 .
During peak operation or base-load operation, the valve 51 closes airflow to the conduit 54 and allows airflow from conduit 52 to conduit 53 . Thus, relatively cool air is provided to the turbine section 30 to cool components of the turbine section, such as a shaft, buckets, and nozzles. However, when cool air is provided to the turbine section 30 during part-load operation, efficiency of the turbine 1 decreases.
Accordingly, during part-load operation, the valve 51 closes airflow to the conduit 53 and allows airflow through the conduit 54 to the exhaust section 40 . The air flows through the heat exchanger 41 of the exhaust section 40 and through the conduit 55 from the exhaust section 40 to the turbine section 30 . Consequently, the air that flows from the heat exchanger 41 through the conduit 55 to the turbine section 30 is heated, thereby increasing the efficiency of the turbine section by reducing heat loss of the air from the combustion section 20 to the turbine section 30 .
In other words, according to the present embodiment of the invention, the components of the turbine section 30 are cooled by the bypass circuit 50 during peak-load operation to prevent overheating of the components while relatively high temperatures are output to the turbine section 30 from the combustion section 20 . However, during part-load operation, in which temperatures output from the combustion section 20 to the turbine section 30 are low relative to peak-load operation, the bypass circuit 50 provides heated air to the turbine section 30 to reduce heat-loss of the air provided from the combustion section 20 . Consequently, dual objectives of cooling components during peak-load operation and increasing efficiency during part-load operation are met.
FIG. 2 illustrates a turbine control system. The turbine control system includes the turbine 1 and a turbine control unit 60 . The turbine control unit 60 includes, for example, a processing unit 61 , memory 62 , and an interface unit 63 . The turbine control unit 60 receives input data I via a terminal 68 , and outputs control signals A, B, C, and D via terminals 64 , 65 , 66 , and 67 .
During operation, the turbine control unit 60 receives instructions or commands to operate the turbine 1 at part-load. The instructions are input to the interface unit 63 , which includes at least one of a wired port and a wireless port or antenna. The interface unit 63 transmits the instructions I to the processing unit 61 . The processing unit 61 determines whether the instructions I correspond to a part-load operation and controls the control signals A-D accordingly. According to one embodiment, the processing unit 61 compares a level of load in the instructions I with a predetermined level stored in memory 62 to determine whether the instructions I correspond to part-load operation.
For example, the control signal A adjusts an air intake of the compressor 10 by adjusting characteristics of an intake control device 12 . In the present embodiment, the intake control device 12 is one of vanes having adjustable openings between adjacent vanes and a fan. Control signal B controls the inlet 22 of the combustion chamber 21 to reduce fuel input to the combustion chamber 21 in part-load operation. Control signal C adjusts fuel supplied from a fuel supply 23 to the combustion chamber 21 via the conduit 24 . Control signal D controls the valve 51 to close the outlet 57 , and to open the outlet 58 , in part-load operation.
During peak-load operation, the bypass circuit 50 takes in air from the compressor 10 via the outlet 11 . The air enters the valve 51 via the inlet 56 and exits the valve 51 via the outlet 57 . The relatively cool air travels through the conduit 53 and enters the turbine section 30 via the inlet 31 . During off-peak or part-load operation, the relatively cool air exits the valve 51 via the outlet 58 , travels through the conduit 54 , and enters the heat exchanger 41 of the exhaust section 40 via the inlet 42 . The heated air exits the exhaust section 40 via the outlet 43 , travels through the conduit 55 , and enters the turbine section 30 via the inlet 32 .
FIG. 2 illustrates conduits 53 and 55 connected to opposite sides of the turbine section 30 for clarity and for purposes of illustration. However, according to some embodiments the conduits 53 and 55 each introduce air into the turbine section 30 at a plurality of locations around the turbine section.
While FIG. 2 illustrates separate conduits 53 and 55 connected to separate inlets 31 and 32 , according to some embodiments, the conduits 53 and 55 are connected to each other. FIG. 3 illustrates an example of the conduits 53 and 55 connected to each other to introduce air into the same inlets. As illustrated in FIG. 3 , each of the conduits 53 and 55 is connected to a connection conduit 71 , which feeds to the inlets 72 in the casing 76 of the turbine section 30 . The inlets 72 correspond to the inlets 31 and 32 of FIG. 2 . The turbine section 30 comprises a shaft 73 having buckets 74 that rotate around the shaft 73 , and nozzles comprising vanes 75 with openings between the vanes 75 to direct air from a direction of the combustion section 20 onto the buckets 74 to drive the shaft 73 . In the present embodiment, the inlets 72 are located at positions corresponding to the vanes 75 . The air from the bypass circuit 50 , represented by arrows into the turbine section 30 , flows into the inlets 72 , down the length of the vanes 75 in tubes located within the vanes 75 , out of the vanes 75 in the vicinity of the shaft 73 , and into the space between the vanes 75 and the buckets 74 .
While FIG. 3 illustrates the conduits 53 and 55 connected to the connection conduit 71 , according to alternative embodiments, the conduits 53 and 55 are connected to separate inlets corresponding to each vane 75 . In other embodiments, the conduits 53 and 55 are connected to alternating vanes 75 .
FIG. 4 is a flow diagram illustrating a control operation of the turbine 1 . In operation 301 , an operation mode is detected. The turbine control unit 60 receives an input instruction or command Ito operate the turbine 1 at a predetermined load. If it is determined in operation 302 that the turbine 1 is operating at peak-load, then air from the compressor 10 in the bypass circuit 50 , or a bypass flow, is channeled directly to the turbine section 30 , bypassing the exhaust section 40 . In such a case, the turbine control unit 60 outputs control signals B-D to provide peak-load levels of fuel to the combustion chamber 21 , to close the outlet 58 from the bypass valve 51 to the exhaust section 40 , and to open the outlet 57 from the bypass valve 51 to the turbine section 30 . In addition, according to some embodiments, the turbine control unit 60 controls the level of intake air to a peak-load level by controlling the intake control device 12 with control signal A.
If it is determined in operation 302 that the turbine 1 is operating at part-load, the bypass flow from the compressor 10 is diverted through the heat exchanger 41 of the exhaust section 40 to heat the bypass flow. The turbine control section 60 detects that the instruction I is to operate the turbine 1 at part-load, and adjusts control signals B-D to reduce the fuel provided to the combustion chamber 21 , to close the outlet 57 from the bypass valve 51 , and to open the outlet 58 from the bypass valve 51 . The bypass flow from the bypass valve 51 flows through the conduit 54 to the heat exchanger 41 , and the heated bypass flow is returned to the turbine section 30 via the conduit 55 .
Accordingly, during peak-load operation, a cooling bypass flow is applied to a turbine section 30 to maintain within a predetermined range a temperature of the components of the turbine section 30 , and during part-load operation, the cooling bypass flow is heated and supplied to the turbine section 30 to improve operating efficiency of the turbine 1 .
While the embodiments above have described the bypass flow as being heated by the exhaust section 40 , according to alternative embodiments, any heating source may be used to heat the exhaust. FIG. 5 illustrates a turbine 1 in which the bypass circuit 50 selectively transmits the bypass flow through a heating unit 80 . The heating unit 80 includes any one of the exhaust 40 , a steam source, a heat exchanger, and a fuel combustion unit, for example.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
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A method of controlling the part-load performance of a turbine includes generating a bypass flow in the turbine by removing a portion of a compressed fluid from a compressor of the turbine, determining an operating load of the turbine, transmitting the bypass flow to a turbine section of the turbine; and selectively heating the bypass flow according to the determined operating load of the turbine.
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TECHNICAL FIELD
This invention relates to intraocular implant lenses and more particularly to a lens of light weight wherein the implanted weight is distributed over a large area to minimize the localization of support forces.
BACKGROUND ART
Lens implants on patients requiring surgery because of the presence of cataracts are widely practiced. Developments leading to acceptance of the technique and of lenses designed for implant are discussed in "A Lens For All Seasons" by Jerald L. Tennant, 1976. The development of the Choyce lens and the Tennant lens has lead to wide acceptance with many hundreds of implants being performed using such lenses. In such systems the lens is placed in the anterior chamber. Fixation of the lens is assured by four point contacts made by feet extending from the lens proper.
It has been found to be desirable to minimize the localization of the lens contact with the supporting tissues. Localized pressure by some prior art lenses has a tendency to cause distortion of the pupil after a period of time. Thus, the present invention is directed towards a lens suitable for implant in either the anterior chamber or the posterior chamber with minimal tissue loading.
DISCLOSURE OF THE INVENTION
In accordance with the present invention an intraocular implant lens unit is provided comprising a central lens structure having a narrow twelve o'clock limb and a narrow six o'clock limb integral with and extending radially from opposite margins of the lens. A narrow arcuate rim segment is centered on and is integral with the end of the twelve o'clock limb and extends for about the width of the optic. A narrow arcuate rim segment is centered on and is integral with the end of the six o'clock limb and extends for about twice the width of the optic. The arcs have a center at the center of the lens and are of diameter corresponding to the diameter of the chamber in which it is to be fitted so that the outer edges of the rim segments bear against the inner wall of the chamber.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of an anterior chamber lens;
FIG. 2 is a side view of the lens of FIG. 1;
FIG. 3 is a front view of a posterior chamber lens;
FIG. 4 is a side view of the lens of FIG. 3; and
FIG. 5 illustrates the lens of FIGS. 3 and 4 mounted within the posterior capsule.
DETAILED DESCRIPTION
FIGURE 1
Referring to FIG. 1 an optic lens 10 of plano-convex shape is formed integrally with a six o'clock limb 11 and a twelve o'clock limb 12. Limbs 11 and 12 thus extend diametrically in opposite directions from the lens 10. A rim segment 13 is integral with and formed at the end of the limb 11 opposite lens 10. The arc segment 13 spans an arc of about 60° and is of generally the same thickness and width as the limb 11. It lies in the plane perpendicular to the axis of the lens 10 and presents a curved outer surface 13a which is preferably rounded on the edges and smooth to provide contact over the entire length of the surface 13a with the margin of the anterior chamber into which the lens is to be placed.
A second rim segment 14 is integrally formed with and is located at the end of the twelve o'clock limb 12. The rim segment 14 preferably is of a chord length equal to the diameter of the lens 10. It is much shorter than the rim segment 13 and is designed to engage along its outer surface 14a and the inner margin of the anterior chamber in which it is to be located.
In a typical embodiment, the lens 10 would have a diameter of 4 to 6 millimeters; thus, the chord length of the rim segment 14 would be 4 to 6 millimeters. The chord length of the rim segment 13 would be approximately twice the chord length of the rim segment 14, i.e., 8 to 12 millimeters. Typically the radius of the outer surfaceS 13a and 14a of rim segments 13 and 14 would be of the order of 12.5 millimeters.
FIGURE 2
FIG. 2 is a side view of an embodiment of FIG. 1 wherein the lens 10 is plano-convex. It will be noted that the limbs 11 and 12 extend posteriorly relative to the posterior surface of lens 10 as well as radially.
It is to be noted that the implant unit of FIGS. 1 and 2 essentially retain the equivalent of four point fixation which prevents rotation of the lens. Rotation is also discouraged by having the long inferior rim. The inability to rotate is an important feature.
Corneal dystrophies of older triangular lenses such as known in the prior art occur primarily when the lens rotates in the eye causing continual endothelial cell damage. The weight of lenses currently used in greatest volume cannot be reduced by simply fenestrating the lens. Such expedients have been tried and found that the iris would herniate through the fenestrations. Further where point contact is made between a foot of a lens and the iris, there is a tendency to incarcerate the lens in the iris or in the ciliary body. Such incarceration is avoided with the lens shown in FIGS. 1 and 2 since the rim surfaces 13a and 14a have the same radius as the radius of the scleral spur.
By providing the limbs 11 and 12 with posterior inclination as well as radial extension, clearance of the iris of from 1/2 to 3/4 of a millimeter is provided to avoid rubbing of the iris tissue.
While the optic of FIGS. 1 and 2 has been shown as of plano-convex configuration it will be understood that it may be made convex-plano or biconvex. However, plano-convex configuration is preferred inasmuch as it provides maximum spacing between the iris and the posterior surface of the lens. Irritation in the postoperative period of the raw edges of the iris is thus avoided.
FIGURE 3
FIG. 3 illustrates a lens embodying the present invention suitable to be placed in the posterior chamber of an eye after an extra-capsular cataract extraction has been performed. It is not suitable, of course, for use after intracapsular extraction inasmuch as the capsule itself is used for fixation.
Referring to FIG. 3, lens 20 is provided with radial limbs 21 and 22. Limb 21 is integral at the end thereof with a rim segment 23 and has generally the same characteristics as above described in connection with FIG. 1.
Similarly limb 22 terminates in and is integral with a shorter rim segment 24. Rim segment 24 is pierced by a small hole 25 which is centered on a radius extending from the center of lens 20 and is centered in the rim segment 24. A slit 26 extends from the aperture 25 about to the surface 24a of the rim segment 24.
FIGURE 4
As shown in FIG. 4 lens 20 is plano-convex and has an anterior surface 20a which lies in the same plane as the anterior surface of the limbs 21 and 22 and the anterior surface of the rim segments 23 and 24.
FIGURE 5
In FIG. 5 the lens 20 is shown in position in the posterior chamber. The diameter of the circular rim surfaces 23a and 24a is the same diameter as the diameter of the capsular bag and cannot therefore decenter. The inferior arms are fitted into the interior of the capsular bag for fixation. The vectors of weight of the lens make it want to remain centered. The inferior curve surface 23a of the lens may be manipulated to glide easily into the bag without a tendency to penetrate the posterior capsule. Thus the lens of FIGS. 3 nd 4 will fixate and center in most cases without any additional fixation.
An additional unique provision is present in the lens of FIGS. 3 and 4 enhancing the ability to fixate the upper limb of the lens to the iris. This is achieved by providing a radial slit 26 extending from surface 24a into the aperture 25. In utilizing the same, an iridectomy is made over the rim segment 24. A piece of the iris is pressed through the slit 26. This may be achieved utilizing a small caliber blunt instrument. Thus the iris is grasped by the lens in a clipping or clawlike action. This further prevents the lens from dislocating should capsular fixation not occur by reason of the contact to the inferior supporting surface 23a. In addition, fixation at slit 26 utilizes the pendulum effect further to enhance fixation.
In FIG. 5 the jagged margins 30, 31 and 32 represent the opening made into the capsule for fragmentation and removal of the lens. The opening is adequate to receive the inferior rim segment 23 and to accommodate the insertion of the ends of the rim segment 24. The inner surface of the posterior capsule 33 may be viewed through the opening. The surface of the anterior capsule 34 only in part remains intact.
Typically the posterior chamber lens of FIGS. 3-5 would have the lens portion 20 of 4 to 6 millimeters in diameter with the rim segment 24 of about the same chord length and with rim 23 about twice such chord length and with the diameter of the outer surfaces 23a and 24a from the center of the lens 20 being of the order of 11.5 millimeters.
It will be understood that FIGS. 1 and 3 have been illustrated with the lenses oriented as would be viewed by the physician during an implant procedure. FIG. 5 on the other hand is a view of the lens area with the iris removed in order to permit the interior limbs to be shown as they are positioned within the capsular bag. In FIG. 5 the lens is in the position as to be viewed by an observer facing the patient with the implant.
The lens, limbs and rims may all be made of rigid material suitable for eye implant. Such material may be of the nature of polymethylmethacrylate (PMMA). In accordance with the principles described in Applicant's co-pending application Ser. No. 28,609, filed Apr. 9, 1979, the unit used for anterior chamber implantation may be made up of different materials for facilitating the accommodation of a lens through muscular action in the eye. For example, the lens itself and the rims may be of rigid material, such as polymethylmethacrylate (PMMA), while the limbs may be of a softer material of the nature of hydrogels (PHEMA).
Thus from the foregoing it will be seen that an intraocular implant lens is provided comprising a central circular lens with a narrow 12 o'clock limb and a narrow arcuate rim segment centered on the end of the 12 o'clock limb and extending about 15° along with a narrow six o'clock limb supporting a rim segment of about 30° arcuate extent. The arcuate segments have their center at the center of the lens and are of diameter of the chamber in which they are to be fixed.
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An intraocular implant unit having a lens (10) with a first limb (11) and a second limb (12) integral therewith and extending outward radially from opposite margins thereof. A long arcuate rim (13) is centered on the end of the first limb (11) and a short arcuate rim (14) is centered on said second limb (12) wherein the rims (13, 14) and limbs (11, 12) are substantially less in lateral dimension than the diameter of the lens (10) for minimizing the weight of the implant unit while assuring positive fixation.
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This is a divisional of co-pending application, Ser. No. 06/803,282, filed Dec. 2, 1985, now U.S. Pat. No. 4,612,224.
BACKGROUND OF INVENTION
Structural substrates for panels are generally formed of compression molded fibrous webs which are cut and molded into the shape required. Such substrates are used to back up interior paneling members, such as door panels and the like within automobiles and for other analogous uses. In the current methods of manufacturing the web material, which is later cut and compression molded, it is conventional to mix together fibers of wood and synthetic plastic which are distributed, by means of conveyor belts and suitable distribution rollers, and the like into non-woven fiber mats. A powdery, synthetic resin molding compound is applied to such mats. The mats are then heated to partially cure the molding compound. This gives the resulting web sufficient structural integrity so that it may be picked up, handled, moved about and positioned within mold cavities. Since the resinous material is only partially cured, a substantial portion of it remains uncured. That uncured portion is cured during the compression molding process by the application of heat and pressure to the material while it is contained within a cavity type of mold.
In the foregoing procedure, the partially cured resinous molding powder tends to form a skin-like crust on the surfaces of the web as well as relatively hard portions within the web so that the web resists easy flexing. Consequently, the web is more difficult to drape within the mold cavity around irregular mold areas, especially those areas which have relatively sharp corners or straight or undercut walls and the like. In addition, such materials are difficult to deep draw because of their relative stiffness and resistance to draping.
Moreover, in such prior procedure, since the resinous material used is partially cured before the molding process, in order to have sufficient molding material available during the compression molding, larger amounts of molding material are needed. Alternatively, the finished substrate has less cured molding material than is desirable.
Thus, there has been a need for a fiber web material which is more pliable and easily drapable within a mold so as to produce sharper corners and better undercut or straight wall areas and which carries a maximum amount, within desired limits, of uncured molding material. The invention herein is concerned with such a web and a method of forming it, which results in a more pliable, drapable, web that can be more deeply and easily drawn in a compression molding operation.
SUMMARY OF INVENTION
This invention relates to a web used in compression molding of structural substrates formed of non-woven randomly oriented blended fibers. The web contains uniformly dispersed dry, completely uncured, resinous molding powder. The fibers are mechanically interlocked to each other and to a non-woven fiber scrim sheet covering at least one face of the web.
The web is formed by successive fiber blending steps in which the fibers are successively spread out into mats which are taken apart and reblended until a final step where the fibrous web, now containing uniformly dispersed dry molding powder, is mechanically locked to a scrim sheet by needling. At that point, the finished web, containing uncured molding powder, has structural integrity, for easy handling, and good pliability or extensibility for easy draping within a compression mold cavity.
The fiber blend is made of a mixture of wood fibers and synthetic plastic fibers, such as nylon, polyester or polypropylene or the like. The percentages of each of the fibers within the blend may be varied depending upon the requirements, costs, etc. For certain applications, it is contemplated to utilize blends of only synthetic fibers, but preferably of different kinds of synthetic plastics.
An important object of this invention is to provide a compression moldable web which has sufficient structural integrity and pliability or flexibility to enable deep drawing of the web in the mold, good draping over irregular mold surfaces, particularly over relatively sharp corners and undercuts. Another important object is to produce a web without the necessity of partial curing of molding powder so that 100% of the molding powder is available for the compression molding. Significantly, the crust or other stiffened resinous areas resulting from pre-curing are eliminated.
Another object of this invention is to eliminate the pre-curing or partial curing of the resinous molding powder web so as to enhance the extensibility of the fiber web during the molding procedure. This produces a more uniform density finished molded substrate without weak points that have occurred in the past due to varying densities or thicknesses of a web stretched within a compression mold cavity.
These and other objects and advantages of this invention will become apparent upon reading the following description of which the attached drawings form a part.
DESCRIPTION OF DRAWINGS
FIG. 1A is a schematic elevational view of the beginning portion of the equipment, and
FIG. 1B is a schematic elevational view, continuing the line of equipment from FIG. 1A.
FIG. 2 is a perspective, fragmentary view, showing schematically a portion of the initial blending portion of the equipment.
FIG. 3 is an enlarged, fragmentary, cross-sectional view of the web before needling.
FIG. 4 is an enlarged, fragmentary view, similar to FIG. 3, showing the needling step, and
FIG. 5 is a view similar to FIGS. 3 and 4 schematically showing the mechanically interlocked fibers and scrim following needling.
FIG. 6 is a fragmentary cross-sectional view of the molded substrate within the mold cavity.
DETAILED DESCRIPTION
Referring to FIG. 1, a bale of wood fibers enters the line of equipment upon a conveyor 11. The wood fibers, for example, may form a bale which is approximately 12 inches ×36 inches, weighing about 60 lbs. and having a moisture content of up to about 20% by weight. The wood is preferably of what is called a soft-hardwood, for example, wood of the aspen family, including yellow poplar, and similar such woods which are commercially available in fiber form.
The bale 10 proceeds into a bale breaker and shredder 12 which is schematically shown. This breaks up and shreds the bale into loose fibers 13 which are deposited upon a removal conveyor 14.
The fibers 13 are deposited into a feed hopper 15 of a dryer 16. Although different commercially available dryers may be used, a preferred dryer is a commercially available, tubular, forced air dryer having a hot air blower 17 which blows air through a long tube. The tube may be over 100 feet in length. The flowing air picks up the fibers entering through the feed hopper and carries them to the discharge orifice 18 of the dryer. This type of dryer is rapid acting and may carry the fibers through, drying them sufficiently to provide optimum molding conditions, such as to 5%, and preferably, to about 3% moisture by weight, in less than a minute.
The fibers exiting from the discharge orifice 18 of the dryer are carried away upon a conveyor 19. This conveyor also receives synthetic plastic fiber which begins as a bale 20 entering into the equipment upon a conveyor 21. A conventional bale breaker and shredder 22, which is schematically shown, shreds the bale into fibers 23 which are deposited as a thin coating over the blanket of wood fibers 13 upon the conveyor 24. By way of example, the coating of synthetic fibers may be on the order of an eighth or a quarter of an inch upon a 2 inch thickness of wood fibers. However, the thicknesses of the fiber deposits may vary considerably, depending upon the nature of the fibers and the fiber ratio of the final specified blend. Preferably, the wood fibers predominate. Optionally, the synthetic fibers 23 may be deposited from conveyor 23 upon conveyor 14 and travel through the dryer 16 with the wood fibers.
The wood fiber and synthetic fiber mixture is carried to a feed conveyor 28 (see FIGS. 1B and 2) where it is raised and dropped into the upper end of a large blending or distributor chamber 29. The fiber is gravity dropped downwardly through the chamber, being spread apart and evenly disbursed by a V-shaped spreader 30 located within the chamber.
The dropping fibers accumulate upon blending rolls 31, pass through the nip of the rolls and then, drop down through the lower end 32 of the blending chamber. The blended mixture of fibers 33 land upon a substantially horizontal collection conveyor 34 which conveys the blended fibers to a sloping conveyor 35. Such sloping conveyor, which has a roughened surface that may have cleats or treads or the like for roughening, carries the fibers upwardly to a pair of spiked or rough surface transfer rolls 38 and 39. These rolls transfer the fibers, while further blending them, to a control valve 40 (shown schematically) which may be in the form of a simple movable louvre or plate. The fibers then drop down, in a controlled volume, into a volumetric control chamber 41.
In FIG. 1B, the chamber 41 is shown as having one solid wall 42 and an opposing wall 43 formed of a conveyor belt which simultaneously moves the fibers downwardly through the control chamber while containing them within the chamber.
The fibers pass from the bottom of the control chamber into a group of spiked or rough surface transfer rolls 44 which carries them to a picker roll 45. The transfer rolls and picker rolls are conventional in equipment used to form non-woven mats. A conventional transfer roll may have spikes in the form of nail-like projections extending radially outwardly from its surface. Likewise, the picker roll is formed with a rough surface, such as a sawtooth-like surface or spikes or the like.
The fibers are transferred to the surface of the picker roll by the transfer roll spikes, the rough surface of the picker roll and also by means of high velocity air which blows the relatively loose fibers upwardly against the lower surface of the picker roll. The high velocity air is applied by a means of a suitable blower air duct 46 which extends the length of the picker roll. High velocity air for the duct is supplied by a suitable compressor or blower 47 which is schematically shown.
When the fiber is blown and conveyed upon the picker roll, it is further blended and forms an initial web or blanket 48, which is relatively weak. This web or blanket passes between an upper condenser roller 49 and a lower condenser roller 50 which compress the web and directs it to a conveyor 51.
As the web moves with the conveyor 51, it passes beneath a resin hopper 54 which is loaded with a dry powdery, resinous molding material 55, such as a phenolic resin powder. An example of such a material is a phenolformaldehyde novolac type resin containing hexamethylenetetramine for cure purposes supplied in powder form by Polymer Applications, Inc. and identified as PA-60-706 resin.
The resin powder drops downwardly upon the web passing beneath it for dispersion through the web. The resin powder filled web next passes through a group of spiked transfer rollers 56 and is carried around to a second, rough surface picker roll 57, aided by compressed air from an air duct 58. The compressed air is supplied by an air blower 59 which is schematically shown.
A secondary, further blended, web 60 is formed by the second picker roller operation and passes through a duct 61, aided by the flow of compressed air from the air duct 58. This secondary web is passed between an upper condenser roller 62 and a lower condenser roller 63. Preferably, the upper condenser roller has a solid or air impervious surface while the lower condenser roller has a perforated surface to permit the escape of the compressed air from the duct 61.
Next, the web is conveyed upon a transfer conveyor 64 to a point where scrim 65 is applied. The scrim may be arranged in a suitable roll and unwound to cover the moving web.
The scrim is made of a thin sheet of non-woven synthetic fiber material, such as nylon, rayon, polypropylene and the like in the form of, for example, a thin, randomly oriented, fibrous scrim sheet. An example of a commercially available scrim material is spun bonded nylon supplied by Monsanto. The particular kind of scrim material selected depends upon availability, cost, product specifications, etc.
The scrim may be applied either upon the upper surface or the lower surface of the web or even upon both surfaces, if required for the particular finished product. The scrim shown in the drawing is applied to the lower surface of the web and the composite web-scrim material passes into a conventional needling machine 66. This machine has a head 67 and a base 68. Numerous needles 69 (see FIG. 4) are secured to the vertically reciprocating head 67 and enter into sockets 70 formed in the base 68.
The needling operation disrupts and intertwines the fibers that are contacted by and displaced by the needles. Thus, the fibers mechanically interlock with each other and also interlock with the scrim. Consequently, as schematically illustrated in FIG. 5, there appear to be lines of interlocked fibers and an interlocking between the fiber blanket and the scrim sheet which mechanically fastens the material together.
The web moving out of the needling machine 66 is grasped by takeout rolls 71 and passes into a conventional, side trim roller cutter 72 for trimming and straightening the side edges of the web. Then the web proceeds through a blade type cutter 73, or some suitable conventional cutter, for chopping the web into required lengths. These are removed upon a removal conveyor 75.
As illustrated in FIG. 5, the finished composite fiber-scrim, mechanically interlocked web 78 has areas of interlocked fibers 79 which provide the composite web with structural integrity and sufficient strength for handling. The finished web comprises a thoroughly blended or intermixed fiber composition with the powdered resin thoroughly and evenly dispersed through the web. All of the molding powder is uncured and available for molding when the material is placed within a conventional compression mold for heat and pressure molding into a desired shape.
Although the fibers and the handling of the fibers may vary in accordance with the procedure described above, examples of useful web compositions are as follows:
______________________________________ Preferred Approximate Range Approximate % by Weight % by Weight______________________________________Example I - CompositionWood Fiber 50-80 69Synthetic Fiber 0.02-10 9Resin (thermoset) 10-18 16Wax 0-3 2Water less than 5 4 100Example II - CompositionWood Fiber 60-70 66Synthetic Fiber 0.02-10 8Resin (thermoset/ 15-25 20thermoplastic)Wax 0-3 2Water less than 5 4 100______________________________________ Examples of typical materials used in the composition are: Wood fiber: aspen, poplar, pine, etc. e.g., roughly 35-45% retained on 8 mesh screen, with 17% moisture content Synthetic fiber: nylon, polyester, etc. e.g., Nylon 6 or 66, 1/2"-11/2" length, 9-15 denier (thickness of fiber) Thermoset resin: phenolic, epoxy, urethane, etc. Thermoplastic resin: polyvinyl chloride, polypropylene, etc. Wax: hydrocarbon, etc., e.g., Fuller WW0089 Scrim: Monsanto, spun bonded nylon, 0.03 oz. per square yard
For certain requirements, the natural wood fibers may be replaced in whole or in part by other natural fibers. Examples of such compositions, using shoddy, i.e., cotton, wool, etc., as follows:
______________________________________ Preferred Approximate Range Approximate % by Weight % by Weight______________________________________Example III - CompositionShoddy (cotton, wool, etc.) 50-80 69Synthetic 0.02-10 9Resin (thermoset) 10-20 16Wax 0-3 2Water less than 5 4 100Example IV - CompositionShoddy 65-75 69Synthetic Fiber 0.02-10 9Resin (thermoset/thermo- 14-18 16plasticWax 0-3 2Water less than 5 4 100______________________________________ Ratio (thermoset/thermoplastic): 1/2- 2/1
In compression molding, a mold release wax is frequently desirable. As set forth in the examples, the wax is in a powder form and in a range of up to about 3% and preferably in the range of roughly 2%.
To dry the wood fibers, which typically come with roughly 16 to 20% moisture content, referring to an aspen type wood such as aspen, yellow poplar and the like, the fibers can be blown through the dryer tube which in a commercially form may be about 180 feet long at a temperature of between about 175°-300° Fahrenheit in less than a minute. This drops the moisture content to between about 2-5% and roughly to a preferred 3% moisture by weight.
As can be seen, the wood fibers are deposited, from the broken bales of wood fiber, into a blanket or mat to a depth of roughly 2-3 inches. The synthetic fibers are deposited upon the wood fiber mass to a depth of roughly 1/4 inch. As mentioned before, the depths vary depending upon the percentages of the different fibers in the finished blend. These fibers are mixed repeatedly in order to get the high qaulity blend desired. That is, the fibers are in the first instance thoroughly blended in the blending chamber 29. Then they are re-blended in passing through the transfer rolls and into the volume control chamber 41. Next, they are again thoroughly re-blended and reconstituted into a fiber web in going through the first transfer roll group 44 and picker roll 45. They are again re-blended, but now containing the powder resin, in the second picker roll 57 and transfer roll group 56. This results in a blend uniformity which in the later compression molding operation provides a uniform density, and molded thickness substrate, and eliminates weak areas in both the cloth-like web and the molded substrate.
The finished web is pliable or readily extensible and thus easily drapable within a relatively deep compression mold having sharp corners, undercut areas and the like. The molded part forms relatively stiff, board-like, structural substrates for use in panels, such as the interior of an automotive vehicle door panel which is covered with an outside plastic shell of skin.
As illustrated schematically in FIG. 6, the web is draped within the cavity of die half 81. When the opposite die half 82 is registered to close the cavity, the web is molded under heat and pressure to form the relative thin, stiff substrate 80. By way of a typical example, the molding may be in the temperature range of 350-450 degrees F., with pressure at about 350-600 psi and for 30-60 seconds to produce a 0.10 inch thick substrate from a roughly 1/2 inch thick web.
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A method of forming a fibrous web useful for compression molding stiff, board-like structural substrates for panels by thoroughly intermixing a blend of wood fibers and synthetic plastic fibers with a dry, powdery, resinous molding material uniformly disbursed throughout the blend. The mass of intermixed fibers and resinous molding material is covered with a thin, randomly oriented, fibrous scrim material and the fibers are locked to each other and to the scrim mechanically by means of needling them together. The web is formed by drying wood fibers, spreading them into a mat, covering the mat with the synthetic fibers and thereafter, dispersing the fibers through a dispersion chamber and recollecting and re-spreading them into a web by means of a picker roller, gravity dropping a powdery resinous molding material upon the web, redistributing and intermixing the fibers and the molding material with a second picker roller, applying the scrim and needling the combined scrim and fiber web for mechanically interlocking them.
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The present application is a continuation-in-part of copending U.S. application Ser. No. 08/711,242 filed Sep. 9, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lamp generally and, more particularly, to an improved floor lamp having safety features to prevent risk of fire and injury to persons.
2. Description of the Prior Art
Presently available standing floor lamps and, more particularly, lamps commonly referred to as "torchiere" halogen floor lamps, are known to produce a significant amount of heat from the 300 watt halogen light bulbs used therein. The heat of these light bulbs is a potential fire hazard as well as a burn hazard to persons coming in contact with the top portion or shade of the torchiere lamp or the halogen bulb itself.
Generally, manufacturers of these types of lamps provide warnings to the consumers with respect to potential fire and injury hazards which may be caused by extremely hot halogen lamps. Such warnings may include a tag attached to the power supply cord or a label attached to the inside of the shade near the halogen bulb to warn consumers of the potential burn hazard when changing a halogen bulb. To date, no manufacturer of torchiere style lamps provides any sort of built-in safety feature to protect the consumer from risk of fire or injury due to burns. Accordingly, the present invention is directed to providing safety features for the halogen torchiere style lamps to provide protection to the consumer against risk of fire and injury.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a lamp which includes safety features to prevent potential fire hazards.
It is another object of the present invention to provide a lamp having means for preventing a person from contacting the halogen bulb and risking possible injury due to burning and to prevent objects from coming in contact with the halogen bulb to prevent potential fire hazards.
It is yet a further object of the invention to provide a lamp having a thermostatic control which is responsive to ambient temperature in the vicinity of an operating lamp which terminates power to the lamp upon reaching a predetermined temperature.
It is still a further object of the present invention to provide a lamp having a thermostatic safety feature in which the thermostat will not reset until power to the lamp is terminated for a period of time.
In accordance with one form of the present invention, an electric lamp includes a base for supporting the lamp and a stem portion having a first end coupled to the base and the second end coupled to a light bulb socket. The electric lamp further includes an electrical circuit for providing power to the light bulb socket, the circuit including an on/off switch and a thermostatic switch serially connected to the light bulb socket. The thermostatic switch is responsive to ambient air temperature such that, upon reaching a predetermined value, power to the light bulb socket is terminated or shut off. Preferably, the thermostatic switch includes a means for maintaining the switch in an open circuit position until power to the lamp is turned off for a period of time to allow the thermostatic switch to reset thereby permitting normal operation of the lamp. The means for maintaining the thermostatic switch may be in the form of a resistive heating element. When the thermostatic switch opens in response to ambient air temperature reaching the predetermined value, current is directed to the resistive heating element which maintains the ambient air temperature in the vicinity of the thermostatic switch above the predetermined value thereby preventing the thermostatic switch from resetting. Only upon termination of power to the lamp, e.g., turning the on/off switch to the off position or unplugging the lamp, will the thermostatic switch be allowed to cool down and reset.
Although the thermostatic switch and resistive heating element may each take many forms, the preferred embodiment of the present invention includes a thermostatic switch which is a bimetallic switch and a ceramic resistive heating element.
In order to provide a margin of safety with respect to fire hazards and potential personal injury, the predetermined temperature at which the thermostatic switch opens the electrical circuit is about 65° C. Furthermore, the thermostatic switch is preferably mounted in close proximity to the light bulb socket to sense the ambient air temperature in the hottest region of the lighting fixture.
Although the present invention may be used with any type of lamp, the safety features of the present invention are particularly useful with respect to halogen torchiere floor lamps. Such lamps use high intensity halogen bulbs, usually 300 watts. These lamps create significant heat and potential fire and personal injury hazards. These types of lamps usually include a bowl-shaped shade provided at the second end of the stem. To direct light in an upward direction, the shade includes positioned therein a reflector. Such lamps also include a dimmer means for controlling the intensity of illumination provided by the lamp.
The present invention also discloses a halogen torchiere floor lamp including a base for supporting the lamp, an elongated hollow stem having a first end coupled to the base and a shade coupled to the second end, a light socket positioned within the shade for receiving a halogen bulb and an electrical circuit means for providing power to the lamp. The halogen floor lamp further includes a protective guard mounted within an interior portion of the shade. The protective guard is positioned over at least a portion of the halogen bulb mounted within the light socket thereby obstructing access to the light socket and bulb with minimal obstruction of light. The protective guard is preferably a convex-shaped wire, but it is envisioned that the protective guard may take many different forms. The halogen floor lamp may also include a reflector located in a bottom portion of the shade and wherein the protective guard is mounted to opposite edges of the reflector.
The present invention also discloses a method of controlling the heat generated by a lighting fixture, the method including the steps of: providing an electrical circuit for a lighting fixture, the circuit including a thermostat serially connected with a light socket, the thermostat being responsive to ambient air temperature in the vicinity of an illuminated bulb within the light socket; sensing the ambient air temperature in the vicinity of the illuminated bulb until a predetermined temperature is reached; opening the circuit thereby extinguishing the light in response to the thermostat being subjected to the predetermined temperature. The method further includes the step of maintaining the open circuit until the power to the lighting fixture is turned off for a period of time allowing the thermostat to reset.
A preferred form of the standing floor lamp, as well as other embodiments, objects, features and advantages of this invention, will be apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a standing floor lamp formed in accordance with the present invention;
FIG. 2 is a top plan view of the standing floor lamp formed in accordance with the present invention;
FIG. 3 is a cross-sectional view of the shade portion of the standing floor lamp formed in accordance with the present invention;
FIG. 4 is an electrical schematic of the circuit associated with the lamp formed in accordance with the present invention;
FIG. 5 is a side view of the protective guard shown in FIG. 2 formed in accordance with the present invention;
FIG. 6 is a top plan view of an alternative embodiment of the protective guard formed in accordance with the present invention;
FIG. 7 is a perspective view of still another alternative embodiment of the present invention;
FIG. 8 is a cross-sectional view taken along lines 8--8 of FIG. 7;
FIG. 9 is a detail in partial section of the protective guard in a collapsed position to facilitate packaging of the lamp;
FIG. 10 is a detail in partial section of the protective guard in an upright unpackaged position;
FIG. 11 is a view similar to FIG. 8 of a further embodiment of the present invention;
FIG. 12 is a view similar to FIG. 8 of a still further embodiment of the present invention;
FIG. 13 is a view of the embodiment of FIG. 12 wherein the guard members have been collapsed for packaging; and
FIG. 14 is a view similar to FIG. 8 of yet another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention relates to safety features for lamps and, more particularly, for halogen torchiere-type standing floor lamps. Although the present invention is described herein for use with a torchiere lamp, it is envisioned that these safety features could be used in conjunction with any type of lighting fixture. As illustrated in FIG. 1, a torchiere lamp 10 formed in accordance with the present invention includes a lamp base 2 for supporting the fixture, an elongated stem 4 having a first end attached to a central portion of the base 2 and a second end coupled to a bowl-shaped shade 6. The stem is hollow and includes a rotary switch 8 for controlling the on/off function of the power supply to the lamp. Furthermore, the switch 8 has associated therewith a dimmer switch for controlling the intensity of the lamp in the on position. Lastly, the lamp includes a power cord 12 which can be plugged into any standard AC electrical outlet.
FIG. 2 is a top plan view of the shade portion 6 of the lamp formed in accordance with the present invention. Within the shade portion of the lamp there is a reflector 14 which substantially reflects the light from the lamp in an upward direction. Positioned within the reflector is the halogen bulb 16 which is seated within a socket 18. The socket 18 is electrically connected to the rotary switch 8 and ultimately the power source through power cord 12. The reflector formed in accordance with the present invention includes several slots 22 through the thickness thereof. Lastly, FIG. 2 illustrates a top view of a protective guard 20 which is positioned across and over at least a portion of the halogen bulb and mechanically connected to edges of the reflector 14.
Referring to FIGS. 2 and 5, the protective guard 20 has a substantially convex shape and is positioned perpendicular to the axis of the halogen bulb 16. The protective guard 20 may take any shape or form, e.g., a cage, as opposed to a single bar as shown in FIG. 5. The protective guard 20 will prevent a person from reaching up into the bowl portion of the lamp and possibly coming in direct contact with an extremely hot halogen bulb. Additionally, should something be placed over the shade 6, the protective guard 20 will keep such articles from directly contacting the halogen bulb. The protective guard 20 of the present invention provides the desired safety feature while obstructing the minimal amount of light produced by the lamp. Preferably, the protective guard formed in accordance with the present invention is made from a metal wire having mounting holes formed at opposite ends thereof. Machine screws 24 may be used to attach the protective guard to the edges of the reflector housed within the lamp shade 6. As previously noted, the protective guard may take the form of an open wire cage (not shown) to provide even more protection against possible contact with a potential burn hazard. As illustrated in FIG. 6, the protective guard, i.e., protective guard 20', may be formed from two wires crossed in the middle.
FIG. 3 is a cross-sectional view of the top shade portion 6 formed in accordance with the present invention. As illustrated in FIG. 3, the reflector 14 is mounted to a lower surface of the shade 6. The reflector includes positioned therein the sockets 18 for receiving a halogen bulb 16. Also illustrated in FIG. 3 is protective guard 20 which extends over the bulb mounted in the sockets.
The present invention is directed toward safety features for torchiere type halogen lamps. Accordingly, a torchiere lamp formed in accordance with the present invention includes a thermostat switch to prevent overheating of the lamp and a possible fire hazard. The thermostat switch 30, as illustrated in FIG. 3, is located in close proximity to the halogen bulb, namely, the area between the reflector 14 of the lamp and the metal shade 6.
FIG. 4 is a circuit diagram for the torchiere lamp formed in accordance with the present invention. The circuit includes a power source for providing AC power to the lamp. The power source is connected in series with a switch SW1 which includes an on/off switch 28 in combination with a dimmer switch 32 so that the intensity of the light may be varied from a dim glow to a high intensity. Any known dimmer switch circuitry may be used. For example, a dimmer circuit using a triac has proven to work well in rotary on/off switches, used for lighting fixtures. In normal operation, the switch SW1 will control the intensity of the illumination from the lamp.
To provide the safety feature of the lamp formed in accordance with the present invention, a thermostat is connected in series between the switch SW1 and the socket 18 for the halogen bulb 16. Preferably, the thermostat includes a bimetallic contact 34 and a parallel connected heating element 36. As illustrated in FIG. 3, the thermostat 30 is mounted in close proximity to the halogen bulb 16. Furthermore, as illustrated in FIG. 2, the reflector 14 includes slots formed therein so that heat is readily transferred to the area in which the thermostat is mounted. If the temperature of the ambient air surrounding the thermostat reaches a predetermined temperature based upon the rated temperature of the thermostat, the bimetallic contact will change from a short circuit to an open circuit and the voltage supply is then applied across the heating element 36. Preferably, the heating element is a ceramic element which has been heated by the ambient air and, upon current being applied to the element, generates sufficient heat to maintain the bimetallic contact in an open position until power to the lamp is disconnected by either turning the switch to the off position or unplugging the lamp. Only power disruption will allow the ceramic heating element to cool down and permit the bimetallic element to return to a closed position thus allowing the lamp to operate under normal conditions again. Preferably, the ceramic heating element is a limiting resistor so that current is limited to only the current necessary to maintain the bimetallic contact in an open position. This limited current will not be sufficient to illuminate the halogen bulb.
It will be understood by those of ordinary skill in the art that the thermostat may take many forms. However, in the preferred embodiment, to provide for extra safety, a thermostat which cannot reset until power to the lamp is disconnected is most desirable. Such a thermostat is manufactured by Micro Therm under part no. A71C65-5. In the preferred embodiment, the predetermined temperature for the bimetallic contact to open is 65° C. Furthermore, the time required for the ceramic element to cool and the bimetallic contact to once again reset and close is preferably a sufficient amount of time to allow the entire lamp assembly to cool down, i.e., approximately 10 minutes. Once the bimetallic contact has reset to a closed condition and the ceramic heating element has been allowed time to cool, the lamp will be able to operate under normal conditions.
Generally, overheating conditions occur if an obstruction to the air flow occurs in the area of the shade 6 thus causing the temperature to rise to an unacceptable level. For example, a curtain or other drapery may be in close proximity to a torchiere lamp similar to that formed in accordance with the present invention. Due to the extremely high temperatures generated by a 300 watt halogen bulb, it is possible that the drapery may ignite causing a fire. The present invention including a circuit having a thermostat to terminate power to the lamp upon ambient air temperature around the lamp reaching a predetermined set point, provides greater safety and substantially eliminates any fire hazard. Accordingly, the halogen torchiere lamp formed in accordance with the present invention overcomes the disadvantages of prior art lamps and provides greater safety to the consumer. These safety features include both the thermostat cutoff as well as the protective guard positioned above the halogen lamp to prevent possible injury caused by burns due to the heat generated by a 300 watt halogen lamp.
In one particularly preferred embodiment, the protective guard, i.e., protective guard 50 shown in FIG. 7, includes a pair of elongate intersecting wire members, i.e., lower wire member 52 and upper wire member 54, which each span from one side of reflector 14 to other side, thus forming an X-shaped dome structure which obstructs access to the halogen bulb by such objects as drapes and curtains without significant blockage of light. Wire members 52, 54 are preferably spaced 90° apart from one another about the upper periphery of reflector 14. Of course, it is contemplated herein that the protective guard could employ more than two wire members. It is also contemplated that the members of the protective guard could be secured to the shade, rather than the reflector.
As best shown in FIG. 8, wire member 52 includes a U-shaped detent 56 formed at the center thereof. The U-shaped detent is sized to receive wire member 54 therein. As will be appreciated by those skilled in the art, wire member 54, once captured within U-shaped detent 56, is substantially locked in an upright, vertically oriented position, i.e., it is unable to rotate about the reflector. Each of the wire members preferably has an arch-like configuration to enhance the structural rigidity of the resultant protective guard structure. As a result of both the U-shaped detent and the arch-like configuration of the members, the protective guard structure (as shown in FIGS. 7 and 8) is able to withstand varying loads and/or forces without failure.
As will be appreciated by those skilled in the art, it is desirable that the protective guard be installed at the factory, leaving little or no assembly left for the end user upon unpackaging of the lamp. Although protective guards such as protective guard 20 provide the required degree of protection, the rigid non-rotatable members employed in such structure either 1) require that the structure be assembled by the purchaser after unpackaging the lamp or 2) require its own unique packaging (as compared to packaging for lamps without such guard structures). However, it has been discovered herein that protective guard 50 can be installed on the lamp at the factory and still be packaged in the same packaging used for lamps without such guard structures.
More particularly, wire members 52, 54 are rotatably attached at their opposing ends to reflector 14. As best shown in FIG. 8, each of the wire members includes inwardly-directed fingers which extend through a pair of opposing openings formed in the reflector. By way of illustration, member 52 includes fingers 58, 60 which extend through opposing circular openings 62, 64 formed in the upper portion of the reflector. The wire members are sufficiently flexible as to allow attachment of such members to the reflector. Once attached, the wire members can be rotated about the circular openings through a substantially 180° arc. As mentioned above, wire member 52, 54 could alternatively be attached to the shade.
As discussed further hereinbelow, wire member 52 is preferably biased to an upright, vertically oriented position. Referring to FIGS. 9-10, this may be accomplished by securing a resilient biasing member, i.e., spring clip 66, to the reflector 14. As shown, wire member 52 includes a leg 68 extending perpendicular from finger 58. Leg 68 of wire member 52 acts against the resilient member when the wire member 52 is pivoted to a collapsed state (as shown in FIG. 9). This collapsed state allows such lamps to be packaged in the same packaging as lamps without protective guard structures installed thereon.
Upon release of the collapsed protective guard structure, the resilient biasing member 66 acts against leg 68, thereby urging wire member 52 to its upright position. As wire member 52 is urged to its upright position by the biasing member 66, wire member 54 (which is resting against wire members 52 as shown in FIG. 9) is simultaneously caused to rotate towards its upright position until such time as wire member 54 becomes captured within the U-shaped detent 56 formed in wire member 52. Once wire member 54 is captured in U-shaped detent 56, the protective guard structure becomes locked in the X-shaped dome structure best seen in FIG. 7.
Of course, other types of springs may be used to bias the wire member 52 to its upright position. For example, a coil spring 70 (as shown in FIG. 11) could be secured on one end to leg 68 and on the other end to reflector 14. Additionally, springs could be attached to both sides of wire member 52, and/or could be attached to one or two sides of wire member 54.
In an alternative embodiment, the protective guard structure includes guard members which are permanently fastened to opposing sides of reflector 14 (or alternatively to the shade), but are sufficiently flexible as to allow collapsing thereof for packaging. As shown in FIG. 12, the protective guard structure, i.e., protective guard 50', includes resilient guard members 52', 54'. Guard members 52', 54' are attached to the reflector by, for example, sheet metal screws. Because the guard members are formed from a resilient material, they may be collapsed (as shown in FIG. 13) for packaging of the lamp. Once unpackaged, the resilient guard members return to the dome configuration of FIG. 12, thus providing a protective guard structure which obstructs access to the halogen bulb while minimizing obstruction of light from the bulb.
In a still further embodiment, the protective guard structure, i.e., protective guard 50", is attached to reflector 14 (or alternatively to the shade) in a manner which allows the ends of the guard member to slide through openings formed in the reflector, thus allowing the guard members to be collapsed for packaging. Referring to FIG. 14, the ends of guard member 52" extend through a pair of opposing openings formed in reflector 14. The guard members of protective guard 50" are formed of a material sufficiently flexible as to allow the guard member to be collapsed for packaging (the collapsed position being illustrated in FIG. 14). The member(s) is, of course, biased (by, for example, coil springs 72) to return to an upright, non-collapsed position upon unpackaging of the lamp.
As a result, a collapsible guard structure is provided which may be installed on the lamp at the factory and thereafter collapsed to allow for packaging of the lamp. Upon unpackaging of the lamp by the end user, the spring-loaded guard structure automatically returns to its initial configuration without any involvement by the end user, thus providing a protective dome-shaped structure which obstructs access to the halogen bulb while minimizing obstruction of light from the bulb.
It will be readily apparent to one skilled in the art, and envisioned to form part of the invention to use similar components, although not necessarily identical to those described in the preferred embodiment to provide the safety features discussed herein. Specifically, many different types of thermostats may be used as well as many types of designs for the protective guard.
Although, illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modification may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.
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A lamp with improved safety features to avoid fire and burn hazards. The lamp includes an electrical circuit having a thermostat connected in series with the bulb of the lamp. The thermostat is mounted in close proximity to the lamp's bulb and, upon the ambient air temperature in the vicinity of the thermostat reaching a predetermined temperature, the thermostat effectively opens the electrical circuit, shutting the lamp off. Once power is turned off for a period of time, the thermostat resets and the lamp may be operated again. A protective guard is positioned over at least a portion of the bulb of the lamp to prevent accidental burning.
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The present invention relates to cell based assays used in pharmaceutical drug screening and toxicological testing applications. In particular, the invention relates to a method for determining the effects of external agents on one or multiple cell types, in parallel assays. The assays of the invention utilise scintillant-containing support particles (microcarriers) that are adapted for cell growth.
BACKGROUND OF THE INVENTION
The application of high-throughput screening (HTS) technologies for the discovery and development of new therapeutic drugs is now well established within the pharmaceutical industry. In the HTS process, drug candidates are screened for possible effects in biological systems and for the specificity of selected lead compounds towards particular targets. Primary screening has been addressed by the development of HTS assay processes and assay miniaturisation utilising the microtitier well plate format with 384, 864, 1536 or greater miniaturised wells and are capable of allowing throughput levels of over 100,000 tests/day in primary screening. Lead compounds identified during the primary screening process are then required to undergo further refined screening and testing in a variety of assays in order to investigate the biological compatibility of the compound. Such assays may include receptor binding and enzyme activity assays, in addition to bioavailability, metabolism and toxicology. Secondary screening of lead compounds can identify potentially undesirable side effects and/or secondary therapeutic activities not identified in the primary screening process and these assays are carried out predominantly using cultured cell lines. In comparison with assays used in the primary screening process, secondary screening assays have a much higher level of complexity and more stringent requirements, both in the mechanics of the assay and in the information generated.
The detection of in vitro binding events, such as receptor binding assays, enzyme assays and immunoassays using scintillation proximity assays (SPA) is now an established technology and is used in HTS applications (Cook, N. D., Drug Discovery Today, Vol 1 (7), (1996), 287–294). SPA utilises scintillant-containing microspheres to which ligands (eg. antibodies, binding proteins, etc) have been attached. When a radioisotopically labelled molecule is brought into close proximity to the scintillant in the microsphere, energy transfer from the radioisotopic decay takes place, resulting in the emission of light. Any radioisotope remaining free in solution, will dissipate its energy into the aqueous medium and will remain undetected. SPA has also been applied to the study of cellular biochemical processes in situ, using cultured living cells. European Patent No. 650396 discloses a method and an apparatus for studying a cellular process, for example, a microwell plate. Each well of the microwell plate includes a scintillant layer in the base, which is further treated to facilitate the attachment and/or growth of cells. In an alternative format, the device may be a single well or tube which is composed of a non-scintillant containing material, into which is placed a circular, scintillant-containing plastic disc. The method for studying a cellular process includes culturing cells adhering to the scintillant layer, in the presence of a fluid medium, introducing into the fluid medium a reagent labelled with a radioisotope emitting electrons, such that a portion of the labelled reagent becomes associated with or released from the cells adhering to the layer. Scintillation events caused by the proximity of the radiolabelled reagent to the scintillant containing base are detected so as to study the cellular process.
PCT Application No. WO97/40189 relates to a method for quantifying the amount of target nucleic acid such as mRNA in morphologically intact cells, the method comprising the steps of culturing not less than two physically distinct samples of cells on at least one substrate, contacting the cells with a fixative and exposing the fixed cells to a labelled nucleic acid probe to hybridise with the target nucleic acid sequence. This invention is concerned therefore with measurements of hybridisation of nucleic acid probes to fixed cells following processing and washing. The method of the invention does not describe and is not compatible with measurement of dynamic processes in living cells.
PCT Application No. WO 96/19739 describes a solid support for use in radioligand binding assays, the support comprising a plurality of interconnected elements arranged to provide interstitial spaces in which a liquid can flow. The support comprises plastic beads which, in a preferred form may contain a scintillant, and which are fused together to form a solid support for in vitro binding assays. While the solid support may also be used for cell growth, it is stated that the support should preferably not contain a fluorophore.
The use in cell culture of CYTODEX™ Microcarrier support particles (Amersham Pharmacia Biotech) has improved the yields of anchorage dependant cells by increasing the surface area for growth. Properties of these microcarriers include optimised size and density for maximum cell growth, a biologically inert matrix that provides a strong but non-rigid substrate for stirred cultures and transparency for easy microscopic examination of attached cells. Microcarriers can be used in either suspension cultures or monolayer cultures to increase the surface area of the culture vessels and perfusion chambers. The increased surface area allows enables the production of increased densities of cells, viruses and cell products.
SUMMARY OF THE INVENTION
There is now a requirement in the art for secondary screening assay methodologies which are capable of handling the increasing rate of lead drug generation and which are compatible with free-format cellular assays and, in particular, methodologies which enable several different types of cell types and/or treatments with test agents to be monitored in parallel.
According to a first aspect of the invention there is provided a method for the measurement of a cellular process in one or more different populations of cells, the method comprising:
i) providing one or more different populations of cells adhering to support particles said support particles comprising a scintillant substance and being adapted for cell growth; ii) introducing samples of said populations of cells in a fluid medium into separate reaction vessels for each population sampled; iii) introducing into each reaction vessel a reagent labelled with a radioisotope under conditions so as to cause a portion of said radiolabelled reagent to become associated with said cells; and iv) detecting light emission from the scintillant particles caused by radioactive decay of the radioisotope as a means of measuring said cellular process.
According to a second aspect of the invention there is provided a method for the measurement of the effect of a test compound on a cellular process in one or more different populations of cells, the method comprising:
i) providing one or more different populations of cells adhering to support particles said support particles comprising a scintillant substance and being adapted for cell growth; ii) introducing samples of said populations of cells in a fluid medium into separate reaction vessels for each population sampled; iii) introducing into each reaction vessel a sample of a test compound whose effect on said cellular process is to be measured; iv) introducing into each reaction vessel a reagent labelled with a radioisotope under conditions so as to cause a portion of said radiolabelled reagent to become associated with said cells; and v) detecting light emission from the scintillant particles caused by radioactive decay of the radioisotope as a means of measuring the effect of the test compound on said cellular process.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a plot showing uptake of [ 35 S]methionine into CHO cells grown on CYTODEX™/YOx Microcarrier beads in the presence and absence of the uptake inhibitor cycloheximide according to Example 2.
FIG. 2 is a plot showing uptake of [ 14 C]methionine into CHO cells grown on CYTODEX™/YOx Microcarrier beads according to Example 2.
FIG. 3 is a plot showing uptake of [ 3 H]methionine into CHO cells grown on CYTODEX™/YOx Microcarrier beads in the presence and absence of cycloheximide according to Example 2.
FIG. 4 is a plot showing the incorporation of [ 35 S]methionine into CHO cells and HeLa cells grown on CYTODEX™/YOx Microcarriers in the presence and absence of cycloheximide according to Example 3.
DETAILED DESCRIPTION OF THE INVENTION
In a particular embodiment of the second aspect, the measurement of step v) is compared with a measurement of a cellular process in one or more different populations of cells in the absence of the test compound.
By cellular process, it is meant the normal processes which living cells undergo and includes: biosynthesis, uptake, transport, receptor binding, metabolism, fusion, biochemical response, growth and death. In addition to cellular processes resulting from internalisation of the test compound, the method of the invention may be used to measure events at the cell surface, such as ligand binding to cell surface receptors. In this case, the receptor binding comprises a specific binding interaction between the radiolabelled reagent and a specific binding partner located in or on the surface of the cells. The measurement of the cellular process may be performed in real time using a non-invasive technique.
According to the method of the present invention, one or more different populations of cells are grown separately in cell culture on support particles comprising a scintillant substance. Samples of the different cell populations are arrayed into the wells of a multiwell plate and treated with a radiolabelled reagent and optionally a sample of a test compound whose effect on the cellular process is to be measured. For example, a ligand-receptor interaction or ion uptake by cells, may be studied by treatment of each of the cell samples with different concentrations of the radiolabelled reagent. Alternatively, if the effect of a test compound is to be determined, each of the cell samples may be treated with different concentrations of the test compound in the presence of a fixed quantity of the radiolabelled reagent.
Suitably, one or more different cell types may be used in the method of the invention. Culture of cells on a support according to the present invention involves the use of standard cell culture techniques, eg. cells are cultured in a sterile environment at 37° C. in an incubator containing a humidified 95% air/5% CO 2 atmosphere. Alternatively, cells may be cultured in sealed vessels containing an atmosphere of air/5% CO 2 . Vessels may contain stirred or stationary cultures. Various cell culture media may be used including media containing undefined biological fluids such as foetal calf serum, as well as media which is fully defined, such as 293 SFM II serum free media (Life Technologies Ltd., Paisley, UK). The invention may be used with any adherent cell type that can be cultured on standard tissue culture plastic-ware. Such cell types include all normal and transformed cells derived from any recognised source with respect to species (eg. human, rodent, simian), tissue source (eg. brain, liver, lung, heart, kidney skin, muscle) and cell type (eg. epithelial, endothelial). In addition, cells which have been transfected with recombinant genes may also be cultured and utilised in the method of the invention. There are established protocols available for the culture of diverse cell types. (See for example, Freshney, R. I., Culture of Animal Cells: A Manual of Basic Technique, 2 nd Edition, Alan R. Liss Inc. 1987). Such protocols may require the use of specialised coatings and selective media to enable cell growth and the expression of specialist cellular functions. None of such protocols is precluded from use with the scintillant-containing support particles used in the method of the invention. Optionally, the cells may be additionally treated with a stain that permits visualisation of the cells cultured on the surface of the support particles. Suitable stains may be selected from crystal violet, neutral red, calcein-AM, Giemsa, Haematoxylin, or other histological stains.
Detection of the light emission from the scintillant containing support particles may be performed by non-imaging counting (such as liquid scintillation counters, or luminometers). Alternatively, detection may be accomplished by imaging techniques, preferably by means of a charge coupled device (CCD) imager (such as a scanning imager or an area imager) to image all of the wells of a multiwell plate. Imaging is quantitative and fast, and instrumentation suitable for imaging applications can now simultaneously image the whole of a multiwell plate.
The effect on cellular structure and function of many types of biomolecules may be studied using the method of the invention. Thus, any molecule that can be radiolabelled and can be transported into, or metabolised by cells, or can interact with the cell surface or bind with cell surface receptors, may in principle be studied. Examples of biomolecules include: amino acids, nucleosides, nucleotides and analogues thereof, oligonucleotides, nucleic acids (eg. DNA and RNA), lipids, hormones, peptides, proteins, carbohydrates, ions (eg. calcium, potassium, sodium, chloride) and receptor ligands. The method is particularly suitable for determining the effect on a cellular process of test compounds, such as those compounds whose metabolism and toxicology towards particular cell types is under investigation. Examples include: drugs, enzyme inhibitors, antagonists and the like.
The method according to the second aspect of the invention is particularly suitable for the parallel analysis of the effect of a test compound on several different cell types and/or treatments, where growth of the different cell types is incompatible in a single multiwell plate. Cells are grown separately on support particles and samples of the different cell populations are arrayed into individual wells of a conventional multiwell plate for treatment with a test compound. The effect of the test compound on the cell process is then determined. The method is particularly suitable for the measurement of the effect of a test substance on cells in real time and where the assay format does not affect the viability or integrity of cells under study.
As an alternative, multiparameter analysis may be performed to determine the effect of a test compound on a cellular process using two or more different cell populations present in the same well. In this embodiment, use is made of different types of support particles, each particle type having a different scintillant substance bound to, or integrated into, the matrix of the particle, wherein each scintillant is capable of emitting spectrally distinct light that may be resolved by imaging. Each different cell type is cultured separately in bulk using a different support particle, and then support particles are combined in a suitable reaction vessel, such as a well of a multiwell plate, prior to the addition of a radiolabelled reagent and a sample of a test compound. Detection of the emissions from the different particle (and hence cell) types is accomplished by CCD-based imaging techniques. Preferably, the measurement of the effect of a test compound may be made on up to three different cell types present in the same well. Particularly preferred are measurements utilising two different cell types.
Suitably, the reaction vessels form the wells of a multiwell plate having 96, 384, 864 wells or more.
Suitably, the radioisotope is one that emits β-particles or electrons having a mean free path of up to 2000 μm in aqueous media. Suitable radioisotopes are those commonly used for labelling biomolecules and used in biochemical applications and include 14 C, 3 H, 35 S, 33 P, 125 I, 32 P, 45 Ca, 55 Fe, 51 Cr, 86 Rb and 109 Cd.
The present invention also pertains to a support for cell based assays performed according to the method. Thus, in a third aspect there is provided a support for cell based assays, said support comprising particles comprising a matrix and having a scintillant substance which has been coated onto, or integrated into, the matrix of the particles and being adapted for cell growth.
Suitably, the support particles employed in the present invention can be composed of any material compatible with the growth of adherent cells, the support particles containing a scintillant substance which has been coated onto, or integrated into, the matrix of the particles. In a preferred embodiment, the support particles comprise polymeric beads, preferably having a porous or macro-porous structure. Suitable polymeric materials include polystyrene, polyvinyltoluene, polyacrylamide, agarose, polycarbonate or dextran polymers. Particularly preferred supports for use in the method are CYTODEX™ Microcarrier supports which are sold under the Trade Mark, CYTODEX (Amersham Pharmacia Biotech) and consist of a biologically inert cross-linked dextran matrix.
The scintillant substance is preferably coated onto or integrated into the matrix of the support particle, such that when a radiolabelled reagent is brought into close enough proximity with the surface of the particle, the scintillant is caused to emit light. Various types of scintillant substances may be used, and are generally selected from organic scintillators and inorganic scintillators. For example, the scintillant can include aromatic hydrocarbons, such as p-terphenyl, p-quaterphenyl and derivatives, and derivatives of the oxazoles and oxadiazoles, such as 2,5-diphenyloxazole and 2-(4-t-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole. A wavelength shifter may also be included in the polymeric composition, the function of the wavelength shifter being to absorb light emitted by the primary scintillant material and re-emit light at a longer wavelength which is compatible with photosensitive detectors in scintillation counters. Alternatively, the scintillant may be composed of an inorganic scintillant such as yttrium silicate (YSi) or yttrium oxide (YOx).
The support particle may alternatively include a scintillant substance which is suitable for imaging applications, such as are disclosed in PCT Application No. WO 99/09415. The scintillant substance preferably has an emission maximum in the range 500 nm to 900 nm and consists generally of an inorganic host material doped with an activator. Examples of host materials are yttrium silicate, yttrium oxide, yttrium oxysulphide, yttrium aluminium gallium oxide (YAG), yttrium aluminium garnet, sodium yttrium fluoride (NaYF 4 ), lanthanum fluoride, lanthanum oxysulphide, yttrium fluoride (YF 3 ), yttrium gallate, gadolinium fluoride (GdF 3 ), barium yttrium fluoride (BaYF 5 or BaY 2 F 8 ), gadolinium oxysulphide, zinc silicate, zinc sulphide and yttrium vanadate. The activator is generally a lanthanide or actinide moiety, and is preferably selected from terbium, europium, erbium, thulium, holmium, dysprosium, samarium, ytterbium, lutecium, gadolinium, uranium and uranyl UO 2 , generally in the form of +2 or +3 ions. Other suitable scintillators are organic chelates of lanthanide or actinide transition metals, such as an imido phosphorane, as disclosed in EP 556005. In multiparameter analysis applications according to the present invention, different support particles are employed, each particle type having a different scintillant substance bound to, or integrated into, the matrix of the particle. In such applications, scintillant substances suitable for bead (and therefore cell) identification are those which have distinguishably different emission spectra. Suitable scintillators include those having emission in the blue region of the spectrum (for example, PVT and YSi:Ce), in the green region of the spectrum (for example, Y 3 (Al,Ga) 5 O 12 :Tb 3+ ) and in the red region of the spectrum (for example, Y 2 O 3 :Eu 3+ ).
The support particles employed in the present invention must be treated or surface modified to allow cell adherence and cell growth. Various types of support surface treatment may be used, including both physical and chemical treatments. A preferred method for treatment of plastic beads involves the use of high voltage plasma discharge (either vacuum discharge or atmospheric discharge) which is a well-established method for creating a negatively charged hydrophilic surface that allows cell spreading and adherence. Cell adherence and growth can be further enhanced by applying additional coatings to the support surface, including: (i) positively or negatively charged chemical coatings such as polylysine, or other biopolymers, (ii) components of the extracellular matrix, including collagen, laminin, fibronectin, and (iii) naturally secreted extracellular matrix laid down by cells cultured on the plastic surface. In the preferred supports for use in the invention, different types of coated and derivatised CYTODEX™ Microcarrier supports are available, such as that formed by substituting the dextran matrix with DEAE (N,N-diethylaminoethyl) groups distributed throughout the matrix, or by substituting the matrix with a surface layer of positively-charged THAMP (N,N,N-trimethyl-2-hydroxyaminopropyl) groups (CYTODEX™ Microcarriers, Technical Data File; Microcarrier Cell Culture, Principles and Methods, Amersham Pharmacia Biotech).
For integrating scintillant material (such as yttrium oxide or yttrium silicate) into the matrix of CYTODEX ™ Microcarrier support particles, the method typically includes forming an emulsion of a mixture of dextran and the yttrium compound in an aqueous solution, followed by cross-linking.
Preferred support particles for use in the present invention are those in the form of a bead having a diameter in the range from 1 μm to 500 μm, and more preferably in the range from 50 μm to 250 μm.
A principal advantage of using the support particles according to the present invention is the achievement of increased surface area for cell growth compared with conventional cell based assays using cells grown in multiwell plates, which may limit some applications in higher density formats. Miniaturisation of assay formats, for example in 1536 and greater multiwell plates, reduces the surface area available for cell growth and hence reduces the number of cells that may be used in an individual assay measurement. In some applications, a reduction in the number of cells/assay may adversely affect the accuracy and precision of the assay. To overcome this, the method of the invention may be used to increase the numbers of cells in an assay while maintaining the miniaturised format as described in the following example.
For a 2 mm×2 mm square well, typical of a high-density multiwell plate, the surface area of the well base is 4 mm 2 or 4×10 6 μm 2 . A typical mammalian cell in culture occupies an area of ˜200 μm 2 , hence it is possible to culture ˜20,000 cells/well by growing cells directly on the well base. For spherical particles of the invention having a diameter of 175 μm, particle area (4πr 2 ) is ˜385,000 μm 2 which will support the growth of ˜1925 cells/particle. If these particles are arrayed in the base of the same 2 mm×2 mm well described above the well can contain ˜130 particles (assuming the beads are packed as a two-dimensional array), this number of beads supports the growth of ˜250,000 cells (˜130 particlesט1925 cells/particle), an increase in cell numbers of 12 fold over growth of cells directly on the base of the well. Further increases in cell numbers may be achieved if required, by the addition of more beads such that multiple layers of beads are formed in the well.
A further advantage of the method of the invention for improving accuracy and precision in miniaturised assays is provided by the ability to use the particles of the invention to grow cells in bulk culture, for example in large stirred cultures, and subsequently to subdivide the bulk culture by dispensing fractions of the culture into individual wells of microwell plates for assay. Growth in, and dispensing from, a bulk culture provides a means of delivering a tightly controlled number of cells to each assay well, and avoids the variance in cell number which may occur for cell cultures grown for extended periods of time in miniaturised wells which may adversely effect assay accuracy and precision. This method has the further advantage of reducing the workload required to culture cells for use in assays by use of a large single culture in place of many thousands of individual cultures in microplate wells.
EXAMPLES
The invention is further illustrated by reference to the following examples which present certain preferred embodiments of the invention but are not illustrative of all embodiments.
1. Preparation of Yttrium Oxide (YOx) Loaded CYTODEX ™ Microcarrier Beads
i) Preparation of Dextran Solution
In a 500 ml beaker with stirring 14 g Dextran TF (MW 200,000) was dissolved in water (33 ml). To this solution was added 50% NaOH (1.8 ml, 2.7 g) and NaBH 4 (0.06 g) followed by yttrium oxide (7.5 g).
ii) Preparation of Emulsion Media
A 1000 ml reactor with an anchor-type stirrer was placed into a waterbath at a temperature of 50° C. Emulgator (6 g) was dissolved in ethylene dichloride (100 ml).
iii) Preparation of Dextran-YOx Beads (SEPHADEX ™ Gel Filtration Media)
The dextran solution prepared above was poured into the emulsion media from step ii) with stirring (100 rpm). Dextran beads containing YOx are formed. Epichlorhydrin (2.1 ml) was added and the crosslinking reaction started. The reaction time was 16 hours at 50° C. The beads were washed with acetone, water and ethanol and were dried in an oven at 50° C.
iv) Preparation of CYTODEX™-YOx Microcarriers (DEAE SEPHADEX™ Gel Filtration Media)
In a 100 ml 3-necked reaction vessel was added in order with stirring: 50% NaOH (2.1 ml), water (9.3 ml), NaBH 4 (0.05 g), toluene (30 ml) and dried dextran beads (5 g). To this was added a 65% solution of diethylaminoethyl chloride hydrochloride (4.5 ml) and the reaction mixture heated at 60° C. for 4 hours. The beads were neutralised with dilute HCl and washed with 0.9% NaCl. The following batches were prepared by the above method:
CYTODEX™/YOx Microcarriers prepared at 3 g YOx/50 ml dextran; CYTODEX™/YOx Microcarriers prepared at 5 g YOx/50 ml dextran; CYTODEX™/YOx Microcarriers prepared at 7.5 g YOx/50 ml dextran.
2. Uptake of Radiolabelled Methionine into CHO Cells Cultured on CYTODEX™/YOx Microcarriers
2.1 Cell Culture Methods
CYTODEX™ and CYTODEX™/YOx Microcarrier beads were dispensed into sterile universal containers. Beads were collected by centrifugation at 100 rpm for one minute. Supernatants were removed and replaced with complete Ham's F12 nutrient mix containing 10% (v\v) FCS. Beads were incubated with rolling at 37° C. for 30 minutes. Beads were harvested by centrifugation at 100 rpm for 1 minute. Spent medium was removed and replaced with 10 7 cells in 500 μl or less. Beads plus cells were incubated at 37° C. for 20 minutes to permit cell attachment to beads. Fresh Ham's F12 medium was added to a final volume of 4 ml containing 5 mg/ml beads for [ 35 S] and 10 mg/ml for [ 14 C] or [ 3 H]. Beads were left to roll overnight at 37° C. Following overnight incubation, beads/cells were harvested by centrifugation at 100 rpm for 1 minute. Supernatant containing unattached cells was removed. Microcarrier beads were washed with PBS (×1) and resuspended in methionine deficient DMEM supplemented with radiolabelled methionine. Cultures were returned to 37° C. with rolling. [ 3 H]Methionine and [ 14 C] or [ 35 S]methionine were included at final concentrations of 8 μCi/ml and 4 μCi/ml respectively.
Following incubation of cells with radiolabelled methionine, 50 μl (250–500 μg beads) aliquots were sampled onto solid white NBS 384 well plates (Corning Costar) and the plate imaged for 5 minutes on a CCD Imaging System (LeadSeeker™, Amersham Pharmacia Biotech).
To demonstrate that uptake of radiolabelled methionine was due to incorporation into cellular proteins and not due to non-specific adsorption of the radiolabel by the beads, experiments were performed in presence and absence of the protein synthesis inhibitor cycloheximide (10 μM final concentration).
2.3 Results
The results are shown in FIGS. 1 , 2 and 3 which demonstrate the incorporation of radiolabelled methionines ([ 35 S], [ 14 C] and [ 3 H]) into CHO cells grown on CYTODEX™/YOx Microcarrier beads. Increases in signal are observed with increasing loading of YOx scintillant. FIG. 1 moreover, illustrates that the uptake of [ 35 S]methionine into CHO cells is inhibited in the presence of protein synthesis inhibitor, cycloheximide.
3. Parallel Assays of the Incorporation of [ 35 S]methionine into CHO cells and HeLa Cells Cultured on CYTODEX™/YOx Microcarriers
3.1 Preparation of Reagents
40 mg of YOx-loaded CYTODEX™ Microcarrier beads were dispensed into suitable sterile containers and allowed to settle. The supernatant was removed from each microcarrier pellet and the beads resuspended in 5 ml of either complete Ham's F12 nutrient mix (Sigma N-4888) or DMEM (Sigma D-6546), both containing 10% FCS, 2 mM L-glutamine and 50 μg/ml streptamycin/50 IU/ml penicillin. The microcarriers were incubated at 37° C. for thirty minutes without rolling.
10×10 6 CHO or HeLa cells in 5 ml complete medium were added to separate microcarrier preparations and the cultures incubated at 37° C. for thirty minutes without rolling. After the initial incubation cultures were incubated overnight at 37° C. with rolling. Following the overnight incubation, unattached cells were removed and the beads resuspended in 10 ml complete culture medium. Microcarriers/cells were maintained in culture until the cell density had reached a sufficient level. Culture medium was replaced every two days.
Cycloheximide was prepared as a 1 mM stock in phosphate buffered saline and added to the cultures at a final concentration of 10 μM.
[ 35 S]Methionine (Amersham Pharmacia Biotech—SJ1015) was prepared as an 8 μCi/ml solution in methionine depleted EMEM (Gibco BRL 31900-012) containing 10% FCS, 2 mM L-glutamine and 50 μg/ml streptamycin/50 IU/ml penicillin.
Each microcarrier preparation was allowed to settle and the growth medium removed. Microcarriers were rinsed twice in sterile phosphate buffered saline and resuspended at 10 mg/ml in [ 35 S]methionine supplemented medium. Cultures were divided into two and cycloheximide added to a final concentration of 10 μM to one and phosphate buffered saline to the other. The cultures were returned to the incubator with rolling. 50 μl Aliquots of microcarriers were removed at timed intervals onto solid white 384-well microplates. Plates were read on the LEADseeker™ Imaging System with a 5 minute exposure time to detect cellular associated methionine.
3.2 Results
FIG. 4 shows that incorporation of [ 35 S]methionine into CHO and HeLa cells can be detected on scintillating microcarriers modified for cell attachment. A signal of 1700 IODs was obtained for CHO cells, 900 IODs for HeLa cells and 650 IODs for ‘no cell’ controls. In the presence of a protein synthesis inhibitor the signal was reduced to 650 IODs for CHO cells and 600 IODs for HeLa cells.
The use of a microcarrier format overcomes the problem of limited growth surface associated with higher density microplates. For a given plate format, the increased surface area provided by the bead surface permits a greater number of cells per well when compared to growing cells on the base of the well.
It is apparent that many modifications and variations of the invention as hereinabove set forth may be made without departing from the spirit and scope thereof. The specific embodiments described are given by way of example only, and the invention is limited only by the terms of the appended claims.
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Disclosed is a method for the measurement of a cellular process, or for the measurement of the effect of a test compound on a cellular process, in one or more different populations of cells. The method comprises providing separate samples of one or more different populations of cells adhering to support particles, the support particles comprising a scintillant substance and being adapted for cell growth. In one embodiment, different samples of cells are introduced into separate reaction vessels in a fluid medium, together with a reagent labelled with a radioisotope, in the presence or the absence of the test compound, under conditions so as to cause a portion of said radiolabelled reagent to become associated with the cells. In another embodiment, multiparameter analysis may be performed to determine the effect of a test compound on a cellular process using two or more different cell populations present in the same well. Measurement of the cellular process, or the effect of a test compound on a cellular process may be made by detecting light emission from the scintillant particles caused by radioactive decay of the radioisotope.
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BACKGROUND OF THE INVENTION
This invention relates to a device for transporting and positioning dough triangles in crescent shaped dough rolls forming machines.
The technique for preparing crescents, also called "croissants", consists in preparing a strip of dough which is rolled on a roller machine.
After some dough strip calibration operations, the strip is transferred into a machine which cuts out triangles.
In order to waste no materials and reduce costs, the triangles are arranged, after the cutting thereof, in parallel rows with opposing orientations, as shown in FIG. 1.
After cutting, the triangles or at least one half of them must be orientated such that they are all presented to the rolling machine with their bases onwards.
On commercially available machines, these orientation operations are carried out by simply turning upside down alternately one half of the triangles, as shown diagramatically in FIG. 2.
The triangles will then enter the rolling machine which comprises essentially a main roller A which carries the dough triangle 2, an upper roller B which guides the dough triangle 1, and two roll-up belts C and D which perform the rolling operation with the aid of the roller A (FIG. 3).
The problem encountered with this processing originates from the fact that the dough, upstream of the cutting station, is located on a continuous conveyor belt, thereby the top face, being exposed to air, is drier than the bottom face which bears onto the belt and is thus prevented from losing moisture.
This position is also satisfactory on the roll-up machine, because the wetter face will adhere on the roller A which transfers it onto the roll-up belts C and D without problems, since a weak adhesion engagement is established between the dough and roller B.
However, when the triangles 1 which have been upturned arrive, the higher adhesion due to higher moisture will occur on the roller B, so that the dough triangle 1 readily separates from the roller A and is not inserted in between the roll-up belts C and D and is instead ejected, as shown in dotted lines in FIG. 3.
This situation produces considerable inconvenience, accompanied by a reduced output, and requires constant attention by an operator for recovering the high number of dough triangles which are not processed.
SUMMARY OF THE INVENTION
It is an object of this invention to remove the drawbacks exhibited by the machines currently in use.
A consequent object of the invention is to provide a device which allows the dough triangles to be taken to the rolling machine all oriented and arranged in the same position.
A further object is to provide a device which enables this orientation to be carried out without the dough triangles being overturned with respect to the position which they occupied on the conveyer belt prior to cutting.
A not unimportant object is to provide a simple and automatic device.
These and other objects, such as will be apparent hereinafter, are achieved by a device arranged in a crescent shaped dough rolls forming machine, wherein dough triangles are arrayed on cutting station leaving conveyor means in at least two rows of triangles with vertices pointing in opposite directions and are transported from said cutting station leaving conveyor means to a rolling station supplying conveyor, a device arranged between said cutting station leaving conveyor means and said rolling station supplying conveyor, characterized in that the device comprises at least two intermediate conveyor means operated with opposite conveying directions for receiving each one of said oppositely pointing triangle rows, each of said intermediate conveyor means having oppositely arranged exit ends where the dough triangles leave the conveyor means, means defining an arcuated conveyor path at each of said exit ends of the intermediate conveyor means, said arcuated conveyor paths converging towards said rolling station supplying conveyor to deliver thereon at least two juxtaposed rows of equaly pointing triangles rows.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention wil be more apparent from the following detailed description of a preferred embodiment, given herein by way of example and not of limitation and illustrated in the accompanying drawings, where:
FIG. 1 shows a series of dough triangles as they appear upon leaving the per se known cutting station;
FIG. 2 is a diagram of how the reversal of the product takes place according to the prior art;
FIG. 3 shows diagramatically a per se known triangle rolling machine;
FIG. 4 is a perspective view of the inventive device;
FIG. 5 is a plan view of the device according to the invention; and
FIG. 6 is a detail view of the device.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1, 2 and 3 shown some main component parts of a known machine, which may be of the type manufactured by the Italian Firm Tecknomatik S.n.c. of 35030 Selvazzano Dentro (Padova) Italy and illustrated in the catalogue of the firm.
Since these component parts are well known at least from the above identified machine, the details thereof are not further described.
With reference to the drawing figures, and as already explained in introducing the prior art, the dough is cut into triangles indicated at 1 and 2, being identifiable by the opposite orientation of the arrayed vertices caused to advance and spread apart on a belt 3.
Said belt 3 alternately feeds two cross belts 4 and 5 which are driven in opposite directions and overlie a wide belt 6 moving toward the rolling machine, not shown. The triangles of the type 1 are dropped from the belt 4 onto the belt 6 through the stage 1' shown like stage 2' in an enlarged scale in a dislocated position for the sake of clarity which, as may be noted, involves turning of the product upside down, whereas the triangles of the type 2 are dropped onto the belt 6 according to the stage 2', i.e. without being turned upside down.
The triangles 1 are turned upside down owing to the fact that the direction of motion of belt 4 is opposite to the one of belt 6, so that at the moment in which a triangle 1 falls edge on onto the belt 6 the inertial forces and the drag of belt 6 cause the turning upside down. Since in case of belt 5 the inertial forces and the drag of belt 6 act in the same direction, no overturning occurs.
In the inventive device (FIGS. 4-6), a conveyor belt 101 causes the cut off triangles to advance, now indicated at 102 with vertex arrayed in one direction, and at 103 with vertex arrayed in the opposite direction. A device 104, of conventional design and already provided in ordinary machines e.g. the above identified one, transfers the rows of triangles 102 and 103 onto two parallel cross belts 105 and 106, respectively.
The belt 105, driven in the direction of the arrow 107, only receives triangles of the 102 type, and moves them to an arched conveyor 108 which causes the triangles 102 to perform a planar rotational movement through an angle of about 120°.
Arched conveyors are well known in the art so that the same are not described here more in detail, it being sufficient to mention that the belt member of the conveyor is made of usual flexible material having the shape of the periphery of a flattened truncated cone.
A successive rectilinear belt 109 located downstream of the former, transports the dough triangles 102 to a first cone 110 or series of cones, which rotates the triangles so as to drop them onto a common conveyor belt 111 with the base 112 lying orthogonally to the mid-axis of the belt 111.
That arrangement is made necessary in order to have the belt 111 bring the triangles to a rolling machine of the type shown schematically in FIG. 3, with one base parallel to the external surface of the cylinder indicated at A.
In order to control or correct the position of the base 112 of the triangle such that it is exactly perpendicular to the mid-axis, and accordingly to the direction of advance of the belt 111, the cone 110 is supported at the vertex by means of a bearing support 113 independently from a second support 114, also of the bearing type, located at the center of the base 115 of the cone 110.
It should be noted that the support 113 is part of a transmission gearing through which rotation is transmitted to the cone 110. Only a gear 213 and the casing 313 of the transmission gearing is diagrammatically shown. Gear 213 is in mash with a ring gear provided on the support shaft 113 of the cone. The transmission gearing 313 is supported in an adjustable manner, allowing angular and translatory adjustments by lever and screw mechanisms not shown, similar to those hereinafter described in connection with support 114. Support 114 is supported by a fixed upright 214 having an elongated hole (not shown) through which a threaded rod 314 is passed, fixed on the upright 214 by means of screw nuts 414. On the end of rod 314 opposite to the upright 214 an elbow shaped lever 514 is fixed on which the support proper 114 is supported. Upon unloosing the screws nuts 414, rod 314 may be shifted upwards within the vertically elongated hole provided in the upright 214 in which the screw nuts 414 and rod 314 are seated and the support 114 may be adjusted in height such that the axis of the cone 110 can be rotated about the support 113. This enables the triangle being transported on the belt 104 to be intercepted on a desired generatrix and moved through a more or less wide angle prior to discharging it onto the belt 111, so that the base of the triangle is arranged precisely along a perpendicular to the axis of the belt 111.
By rotating the threaded rod 314 about its axis and maintaining the screw nuts 414 fixed, the rod 314 together with the support 114 may be horizontally shifted to adjust the spacing between the cone 110 and conveyor 109.
The triangles of the type 103 are discharged on said belt 106, which moves in the direction of the arrow 116, oppositely to the belt 107.
Said belt 106 takes the triangles 103 to a second angled conveyor 117, similar to conveyor 108, and hence to a rectilinear conveyor belt 118 which with the aid of an additional cone 119 transports the triangles to the belt 111, still with the base oriented and arranged along a perpendicular to the axis of the belt 111.
As may be seen, the triangles of the types 102 and 103 which are laid on the belt 101 with reversed bases and vertices, are arranged equi-oriented and side-by-side on the belt 111, having being re-oriented by rotation on a plane and not by overturning.
That being the manner in which the device operates, the dough triangles always maintain, through any transportation phase, one and the same face in contact with the conveyor belt, so that no situations can be originated of different or anomalous adhesion during the rolling up step, which brings about a reduced labor input for controlling the correct arrangement of the triangles fed into the rolling machine.
In practice, the invention affords the possibility of letting the triangle roll-up machine to always work in the same position, thus avoiding any waste problems due to the triangles taking unwanted orientations in the rolling machine.
The advantages of this device will be readily appreciated, as is apparent the technical problem which has been solved thereby.
Of course, based on the same inventive concept which consists of rotating a certain element while keeping it coplanar throughout and without overturning it, through the use of flat conveyor belts, the invention may be embodied differently without departing from the scope thereof.
The materials and dimensions may be any suitable ones to meet individual requirements.
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The device forms an operative station located downstream of the machine which cuts out dough triangles for the production of crescent shaped rolls of dough.
Through the use of parallel conveyors across the direction of advance of the cut dough, which are continued in tracks through a 180° arc, it becomes possible to realign the dough cut into triangles with the same orientation without turning the triangles upside down.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an image signal processing apparatus and, more particularly, to an image signal processing apparatus for adaptively correcting color saturation in accordance with information obtained from image data.
2. Description of the Related Art
The dynamic range of an image pickup element is generally about 50 to 60 dB, and the dynamic range of a TV (television) monitor is about 45 dB. To the contrary, the dynamic range of a general object is as wide as 80 to 100 dB. As a means for solving this problem, a technique is described in, for example, U.S. Pat. No. 4,926,247 by the assigner of the present application.
According to U.S. Pat. No. 4,926,247, outputs from a pair of color image pickup elements are added for each of chrominance signals R, G, and B. Only a luminance signal obtained by matrix conversion is logarithmically compressed by a logarithmic compressor. Gain adjustment or the like of the output from this logarithmic compressor is performed, and each chrominance signal is multiplied by a ratio of this output to the original luminance signal, thereby displaying an image with a compressed dynamic range without changing the chromaticity.
In display of an image by using the technique described in Jpn. Pat. Appln. KOKAI Publication No. 63-232591, when the compression ratio of the dynamic range is increased, the color saturation of the image data seems to be emphasized although the chromaticity of the image data is not actually changed, resulting in unnatural display.
This phenomenon typically occurs at a dark portion of the image. Therefore, when the color saturation of the whole image is simply adjusted, and the dark portion is saturation-adjusted to obtain a natural color tone, the color saturation at a bright portion is excessively suppressed.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a new and improved image signal processing apparatus having a function for adaptively correcting color saturation, in which, in display of an image, even when the compression ratio of a dynamic range is increased and the color saturation is corrected, an excellent color image can be displayed while preventing apparent emphasis on the color saturation at a dark portion without suppressing the color saturation at a bright portion.
According to an aspect of the present invention, there is provided, an image signal processing apparatus comprising:
input means for inputting an image signal including signals related to colors, the input means including means for outputting a luminance signal in the image signal;
dynamic range compressing means for compressing a dynamic range of the luminance signal from the input means;
compression coefficient setting means for obtaining a compression coefficient from a relationship between an output from the dynamic range compressing means and the luminance signal from the input means;
operating means for executing an operation for compressing dynamic ranges of the signals related to colors in accordance with the compression coefficient from the compression coefficient setting means; and
color saturation correcting means for substantially correcting color saturation of the signals related to colors.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1A is a block diagram showing the entire arrangement of an image signal processing apparatus according to the first embodiment of the present invention;
FIG. 1B is a block diagram showing the main part of a modification of the first embodiment;
FIG. 2 is a block diagram showing the detailed arrangement of a color saturation correction circuit in FIG. 1A;
FIG. 3A is a timing chart of an example of the input-output characteristics of an LUT 182 in FIG. 2;
FIG. 3B is a timing chart of another example of the input-output characteristics of the LUT 182 in FIG. 2;
FIG. 4 is a block diagram showing the arrangement of the second embodiment of the present invention;
FIG. 5 is a block diagram showing the detailed arrangement of a color saturation correction circuit 18b in FIG. 4;
FIG. 6 is a timing chart of the input-output characteristics of an LUT 187 in FIG. 5;
FIG. 7 is a block diagram showing the arrangement of a color saturation correction circuit of the third embodiment of the present invention;
FIG. 8 is a timing chart of the input-output characteristics of an LUT 188 in FIG. 7;
FIG. 9 is a block diagram showing the arrangement of the fourth embodiment of the present invention;
FIG. 10 is a block diagram showing the detailed arrangement of a color saturation correction circuit 231 in FIG. 9;
FIG. 11 is a timing chart of the input-output characteristics of an operation circuit 232 in FIG. 10;
FIG. 12 is a block diagram showing the arrangement of the fifth embodiment of the present invention;
FIG. 13 is a block diagram showing the detailed arrangement of a color saturation correction circuit 19 in FIG. 12;
FIG. 14 is a timing chart of the input-output characteristics of an operation circuit 192 in FIG. 13;
FIG. 15 is a block diagram showing the arrangement of a color saturation correction circuit of the sixth embodiment of the present invention;
FIG. 16 is a timing chart of the input-output characteristics of LUTs 196a to 196e in FIG. 15;
FIG. 17 is a block diagram showing the arrangement of a modification in which an operation circuit 192 in FIG. 15 is replaced with an LUT 198;
FIG. 18 is a block diagram showing the arrangement of the seventh embodiment of the present invention;
FIG. 19 is a block diagram showing the detailed arrangement of a color saturation correction circuit 20 in FIG. 18;
FIG. 20 is a timing chart of the input-output characteristics of an LUT 201 in FIG. 19;
FIG. 21 is a block diagram showing the arrangement of the eighth embodiment of the present invention;
FIG. 22 is a block diagram showing the detailed arrangement of a color saturation correction circuit 21 in FIG. 21;
FIG. 23 is a timing chart of the input-output characteristics of an LUT 211 in FIG. 22;
FIG. 24 is a block diagram showing the arrangement of a modification in which an operation circuit 212 in FIG. 22 is not used;
FIG. 25 is a block diagram showing the arrangement of a modification in which the operation circuit 212 in FIG. 22 is replaced with an LUT 217;
FIG. 26 is a block diagram showing the arrangement of the ninth embodiment of the present invention;
FIG. 27 is a timing chart of the input-output characteristics for explaining the operation of the ninth embodiment;
FIG. 28 is a block diagram showing the entire arrangement of the tenth embodiment of the present invention;
FIG. 29 is a block diagram showing the arrangement of a color saturation correction circuit in FIG. 28 and its periphery;
FIG. 30 is a timing chart of an example of the input-output characteristics of a color saturation correction table 271 in FIG. 29;
FIG. 31 is a block diagram showing the arrangement of the color saturation correction circuit in FIG. 28 and its periphery in a modification of the tenth embodiment;
FIG. 32 is a block diagram showing the arrangement of the eleventh embodiment of the present invention;
FIG. 33 is a block diagram showing the arrangement of the twelfth embodiment of the present invention;
FIG. 34 is a timing chart of the input-output characteristics of a color saturation correction table 311 in FIG. 33;
FIG. 35 is a block diagram showing the arrangement of the thirteenth embodiment of the present invention;
FIG. 36 is a block diagram showing the arrangement of the fourteenth embodiment of the present invention;
FIG. 37 is a timing chart of the input-output characteristics of a correction coefficient setting circuit in FIG. 36;
FIG. 38 is a block diagram showing the arrangement of the fifteenth embodiment of the present invention;
FIG. 39 is a block diagram showing the arrangement of the sixteenth embodiment of the present invention;
FIG. 40 is a timing chart of the input-output characteristics of a color saturation correction table 331 in FIG. 39;
FIG. 41 is a block diagram showing the arrangement of the seventeenth embodiment of the present invention;
FIG. 42 is a block diagram showing the arrangement of the eighteenth embodiment of the present invention;
FIG. 43 is a timing chart of the input-output characteristics of a color saturation correction table 341 in FIG. 42;
FIG. 44 is a block diagram showing the arrangement of the nineteenth embodiment of the present invention;
FIG. 45 is a block diagram showing the arrangement of the twentieth embodiment of the present invention;
FIG. 46 is a timing chart of the input-output characteristics of a color saturation correction table 351 in FIG. 45; and
FIG. 47 is a block diagram showing the arrangement of the twenty-first embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the presently preferred embodiments of the invention as illustrated in the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the several drawings.
An embodiment of an image signal processing apparatus of the present invention will be described below with reference to the accompanying drawings.
The first embodiment of the present invention will be described with reference to FIGS. 1 to 3.
FIG. 1A is a block diagram showing the arrangement of the first embodiment.
Referring to FIG. 1A, the image signal processing apparatus is constituted by a photographing optical system 1, a half mirror 2, arranged on the optical axis of the photographing optical system 1, for dividing the optical path, an optical (ND) filter 3 for reducing the light amount of one of the pieces of optical information divided by the half mirror 2, an image pickup element 4a for converting the optical information passing through the optical filter 3 into an analog electrical signal, an image pickup element 4b for converting the other optical information divided by the half mirror 2 into an analog electrical signal, A/D converters 5a and 5b for converting outputs from the image pickup elements 4a and 4b into digital signals, an adder 6 for adding the outputs from the A/D converters 5a and 5b, a look-up table (to be abbreviated as an LUT hereinafter) 7 for correcting the nonlinear input-output characteristics of an added signal from the adder 6 to linear characteristics, and a color separation circuit 8 for separating the corrected signal into chrominance signals R, G, and B.
This image signal processing apparatus also comprises a matrix circuit 9 for generating a luminance signal from outputs from the color separating circuit 8, a logarithmic converter 10 for logarithmically converting the obtained luminance signal, a filter 11 for suppressing the low-frequency components of the logarithmically converted signal, a dynamic range gain control circuit (to be abbreviated as a DGC circuit hereinafter) 12 for adjusting the dynamic range and gain of an output from the filter 11, and an inverse logarithmic converter 13 for performing inverse logarithmic conversion of an output from the DGC circuit 12.
In the first embodiment, an input means for inputting an image signal receives the chrominance signals R, G, and B to output the chrominance signals R, G, and B while a Y signal is output from the matrix circuit 9 (FIG. 1A). The present invention is not limited to this, and a signal of another type may be input to output the Y and chrominance signals. As shown in the tenth embodiment in FIG. 28 (to be described later), the Y and chrominance signals may be output.
This image signal processing apparatus is also constituted by a delay circuit 14 for timing the output from the matrix circuit 9 with an output from the inverse logarithmic converter 13, a compression coefficient setting circuit 16 for dividing an output Y' from the inverse logarithmic converter 13 by an output Y from the delay circuit 14 to output a compression coefficient C, delay circuits 15r, 15g, and 15b for timing the color outputs from the color separation circuit 8 with the output from the compression coefficient setting circuit 16, multipliers 17r, 17g, and 17b for multiplying outputs from the delay circuits 15r, 15g and 15b by the output C from the compression coefficient setting circuit 16, and a color saturation correction circuit 18 for performing saturation correction of outputs R', G', and B' from the adders 17r, 17g, and 17b.
FIG. 2 is a block diagram showing the color saturation correction circuit 18 in detail.
This color saturation correction circuit 18 is constituted by a matrix circuit 181 for obtaining the luminance signal component Y' from the compressed chrominance signals R', G', and B', an LUT 182 for outputting a color saturation correction coefficient in accordance with the luminance signal obtained by the matrix circuit 181, an operation circuit 183 for performing various operations on the basis of the coefficient output from the LUT 182, multipliers 184r, 184g, 184b, and 185, and adders 186r, 186g, and 186b.
The multipliers 184r, 184g, and 184b multiply the compressed chrominance signals R', G', and B' by a color saturation correction coefficient Sc output from the LUT 182. The operation circuit 183 calculates (1-Sc) from the color saturation correction coefficient Sc output from the LUT 182. The multiplier 185 multiplies the Output Y' from the matrix circuit 181 by the output (1-Sc) from the operation circuit 183. The adders 186r, 186g, and 186badd the output from the multiplier 185 to the outputs from the multipliers 184r, 184g, and 184b.
The operation of the first embodiment will be described below with reference to FIG. 1A.
An object image passing through the photographing optical system 1 is divided in two directions by the half mirror 2. One of the divided object images passes through the ND filter 3 and is focused on the image pickup element 4a to be output as an analog signal and converted into a digital signal by the A/D converter 5a. The other of the object images divided by the half mirror 2 passes through the image pickup element 4b and is converted into a digital signal by the A/D converter 5b.
At this point of time, the A/D converter 5a outputs an image signal representing that the dark portion of the object is picked up to become solid black and the bright portion properly is picked up without saturation. On the other hand, the A/D converter 5b outputs an image signal representing that the bright portion is saturated and the dark portion is picked up without becoming black. When these image signals are added by the adder 6, an image signal having information from the dark portion to the bright portion can be obtained. Since the input-output characteristics of this image signal are not linear, the signal is converted by the LUT 7 to have linear characteristics.
The color separation circuit 8 separates the image signal converted by the LUT 7 to be linear into the chrominance signals R, G, and B. The luminance signal Y is extracted from the chrominance signals R, G, and B by the matrix circuit 9. The luminance signal Y' whose dynamic range is compressed is obtained through the logarithmic converter 10, the filter 11, the DGC circuit 12, and the inverse logarithmic converter 13. The compression of the dynamic range of the luminance signal is described in detail in U.S. Pat. No. 4,926,247, and a description thereof will be omitted.
The compression coefficient setting circuit 16 obtains the compression coefficient C=Y'/Y from the output Y' from the inverse logarithmic converter 13 and the luminance signal Y timed by the delay circuit 14. The multipliers 17r, 17g, and 17b multiply the chrominance signals R, G, and B (timed by the delay circuits 15r, 15g, and 15b) by the compression coefficient C to obtain the chrominance signals R', G', and B' chrominance signals whose dynamic ranges are compressed while preserving the chromaticity. The color saturation correction circuit 18 corrects the color saturation of these chrominance signals R', G', and B' to obtain output image signals R", G", and B".
The operation of the color saturation correction circuit 18 as the main part of the first embodiment will be described below with reference to FIG. 2.
The luminance signal component Y' is extracted by the matrix circuit 181 from the R', G', and B' signals input to the color saturation correction circuit 18 to be input to the LUT 182. The multipliers 184r, 184g, and 184b multiply the chrominance signals R', G', and B' by the output Sc from the LUT 182. The operation circuit 183 receives Sc to output (1-Sc). The multiplier 185 multiplies the luminance signal Y' by the output (1-Sc) from the operation circuit 183. The adders 186r, 186g, and 186b add the output from the multiplier 185 to the outputs from the multipliers 184r, 184g, and 184b to output R", G", and B".
The chrominance signals output at this time are as follows.
R"=Sc×R'+(1-Sc)×Y' (1)
G"=Sc×G'+(1-Sc)×Y' (2)
B"=Sc×B'+(1-Sc)×Y' (3)
In this case, only the color saturation can be suppressed without changing the luminance Y'.
As the output Sc from the LUT 182 is smaller, the color saturation is suppressed to be lower. As Sc is larger, the color saturation becomes higher. As for the color saturation correction coefficient Sc, when Sc=0, an achromatic color is obtained. When Sc=1, the original color saturation is preserved.
The input-output characteristics of the LUT 182 represent a monotone increasing function of the output in response to the input, as shown in FIG. 3A. Therefore, the color saturation at a dark portion is more intensively suppressed.
According to the first embodiment, the luminance of the output image signal is not changed, and the color saturation at a high luminance portion is not suppressed. As the luminance becomes lower, the color saturation is more intensively suppressed. Therefore, even when the compression ratio of the dynamic range is increased, an excellent color image can be obtained in which the color saturation at a low luminance portion does not seem to be emphasized.
The input-output characteristics of the LUT 182 represent a linear function in FIG. 3A. However, the present invention is not limited to this, and various characteristics as shown in, e.g., FIG. 3B, can be used as far as they represent a monotone increasing function.
In FIG. 2, only the signals R', G', and B' are input. However, the present invention is not limited to this. For example, when the output from the inverse logarithmic converter 13 in FIG. 1A is used as the luminance signal Y', the matrix circuit 181 can be omitted, thereby obtaining a simpler arrangement.
In FIG. 1A, the color saturation correction circuit 18 is connected to the outputs of the multipliers 17r, 17g, and 17b to correct the color saturation after the dynamic ranges of the chrominance signals are compressed. However, as shown in FIG. 1B, the color saturation correction circuit 18 may be connected to the inputs of the multipliers 17r, 17g, and 17b to correct the color saturation before compression of the dynamic ranges.
In this case, as for the color saturation correction circuit 18 shown in FIG. 2, the input components R'G'and B' can be replaced with R G, and B and the output components R", G", and B" can be replaced with R', G', and B'.
The second embodiment of the present invention will be described below.
FIG. 4 is a block diagram showing another arrangement of the color saturation correction circuit 18 in FIG. 1A.
In the second embodiment to be described below, the arrangement from a photographing optical system 1 to a color separating circuit 8 (none are shown) is the same as in the first embodiment, and a detailed description thereof will be omitted. The same reference numerals as in FIG. 1A denote the same parts in FIG. 4, and a detailed description thereof will be omitted.
The processing section of the image processing apparatus in FIG. 4 is the same as in FIG. 1A except that the arrangement of a color saturation correction circuit 18b is different and, accordingly, an output from an inverse logarithmic converter 13 is added to inputs to the color saturation correction circuit 18b.
FIG. 5 is a block diagram showing the arrangement of the color saturation correction circuit 18b used in the second embodiment.
The color saturation correction circuit 18b is different from the color saturation correction circuit 18 in FIG. 2 in that the matrix circuit 181 and the operation circuit 183 are omitted and an LUT 187 is added. An output Y' from the inverse logarithmic converter 13 is input to LUTs 182 and 187 and a multiplier 185. An output from the LUT 187 is supplied to the multiplier 185.
The operation of the color saturation correction circuit 18b used in the second embodiment will be described below.
The luminance signal Y' compressed and input to the color saturation correction circuit 18b is input to the LUTs 182 and 187. The multipliers 184r, 184g, and 184b multiply chrominance signals R', G', and B' by an output Sc from the LUT 182. On the other hand, the LUT 187 outputs (1-Sc). The multiplier 185 multiplies the luminance signal Y' by the output (1-Sc) from the LUT 187. The adders 186r, 186g, and 186b add the output from the multiplier 185 to the outputs from the multipliers 184r, 184g, and 184b to output R", G", and B".
The input-output characteristics of the LUT 182 represent a monotone increasing function of the output Sc in response to the input Y', as shown in FIG. 3A. To the contrary, the input-output characteristics of the LUT 187 are set to represent a function in which the output decreases with (1-Sc) in response to the input Y', as shown in FIG. 6.
According to the second embodiment, matrix and operation circuits can be omitted in the color saturation correction circuit 18b. Therefore, a simpler circuit arrangement can be obtained, thereby realizing adaptive color saturation correction.
The third embodiment of the present invention will be described below.
FIG. 7 is a block diagram showing the arrangement of a color saturation correction of the third embodiment.
The third embodiment is a modification of the circuit in FIG. 5 and can be replaced with the color saturation correction circuit 18b in FIG. 4. FIG. 7 is different from FIG. 5 in that an LUT 188 for receiving a signal from an LUT 182 is added instead of the LUT 187 for receiving a signal from the inverse logarithmic converter 13. The same reference numerals as in FIG. 5 denote the same parts in FIG. 7, and a detailed description thereof will be omitted.
The operation of the third embodiment will be described with reference to FIG. 7.
A luminance signal Y' is input to the LUT 182. Multipliers 184r, 184g, and 184b multiply chrominance signals R', G', and B' by an output Sc from the LUT 182. The output Sc is also input to the LUT 188. The LUT 188 receives Sc to output (1-Sc). The luminance signal Y' is multiplied by the output (1-Sc) from the LUT 188 in the multiplier 185. Adders 186r, 185g, and 186b add the output from the multiplier 185 to outputs from the multipliers 184r, 184g, and 184b to output R", G", and B".
The input-output characteristics of the LUT 182 represent a monotone increasing function of the output Sc in response to the input Y', as shown in FIG. 3A. To the contrary, the input-output characteristics of the LUT 188 are set to represent a function in which the output decreases with (1-Sc) in response to the input Sc.
According to the third embodiment, matrix and operation circuits can be omitted from the color saturation correction circuit. Therefore, a simpler circuit arrangement can be obtained, thereby realizing adaptive color saturation correction to obtain an excellent color image.
The fourth embodiment in which a color saturation correction coefficient is changed in accordance with the compression ratio of the dynamic range of an image will be described below with reference to FIGS. 9 to 11.
FIG. 9 is a block diagram showing the arrangement of the fourth embodiment.
Referring to FIG. 9, the image signal processing apparatus is constituted by a matrix circuit 9 for generating a luminance signal from signals R, G, and B, a logarithmic converter 10, a filter 11, a DGC circuit 12a for adjusting the dynamic range and gain of an output from the filter 11, an inverse logarithmic converter 13 for performing inverse logarithmic conversion of an output from the DGC circuit 12a, delay circuits 14, 15r, 15g, and 15b, a compression coefficient setting circuit 16 for dividing an output Y' from the inverse logarithmic converter 13 by an output Y from the delay circuit 14 to output a compression coefficient C, multipliers 17r, 17g, and 17b, and a color saturation correction circuit 23 for performing saturation correction of outputs R', G', and B' from the multipliers 17r, 17g, and 17b.
The DGC circuit 12a is constituted by a dynamic range (DR) coefficient setting circuit 121, a multiplier 122 for multiplying an output from the filter 11 by an output α (=0 to 1) from the DR coefficient setting circuit 121, a gain coefficient setting circuit 123, and an adder 124 for adding an output logβ from the gain coefficient setting circuit 123 to an output from the multiplier 122.
The color saturation correction circuit 23 receives the outputs R', G', and B' from the multipliers 17r, 17g, and 17b, the output Y' from the inverse logarithmic converter 13, and the output a from the DR coefficient setting circuit 121 in the DGC circuit 12a.
FIG. 10 is a block diagram showing the detailed arrangement of the color saturation correction circuit 23.
The color saturation correction circuit 23 is constituted by a correction coefficient setting circuit 231 for outputting a color correction coefficient Sc in accordance with the dynamic range coefficient α, an operation circuit 232 for receiving the color correction coefficient Sc to output (1-Sc), multipliers 233r, 233g, and 233b for multiplying compressed chrominance signals R', G', and B' by the color saturation correction coefficient Sc output from the correction coefficient setting circuit 231, a multiplier 234 for multiplying the output Y' from the inverse logarithmic converter 13 by the output (1-Sc) from the operation circuit 232, and adders 235r, 235g, and 235b for adding an output from the multiplier 234 to outputs from the multipliers 233r, 233g, and 233b.
The operation of each part of the fourth embodiment will be described below.
Referring to FIG. 9, the luminance signal Y is extracted from the chrominance signals R, G, and B by the matrix circuit 9 to obtain the luminance signal Y', whose dynamic range is compressed, through the logarithmic converter 10, the filter 11, the DGC circuit 12a, and the inverse logarithmic converter 13. The DGC circuit 12a multiplies α and then adds logβ. Therefore, when the output from the filter 11 is Yf, the compressed luminance signal Y' is represented by equation (4). ##EQU1## where α represents a value within a range of 0 to 1. Therefore, as the dynamic range a is smaller, the compression ratio of the dynamic range becomes higher. As the compression ratio of the dynamic range becomes higher, the color saturation must be more intensively corrected.
The compression coefficient setting circuit 16 obtains the compression coefficient C=Y'/Y from the output Y' from the inverse logarithmic converter 13 and the luminance signal Y timed by the delay circuit 14. The multipliers 17r, 17g, and 17b multiply the chrominance signals R, G, and B (timed by the delay circuits 15r, 15g, and 15b) by the compression coefficient C to obtain the chrominance signals R', G', and B' whose dynamic ranges are compressed while preserving the chromaticity. The color saturation correction circuit 23 corrects the color saturation of the chrominance signals R', G', and B' to output image signals R", G", and B".
The operation of the color saturation correction circuit 23 as the main part of the fourth embodiment will be described below with reference to FIG. 10.
The dynamic range coefficient a from the DR coefficient setting circuit 121 is input to the correction coefficient setting circuit 231. The correction coefficient setting circuit 231 outputs the color saturation correction coefficient Sc in accordance with the input-output characteristics as shown in FIG. 11. More specifically, as a changes, the magnitude of Sc changes accordingly.
The multipliers 233r, 233g, and 233b multiply the chrominance signals R', G', and B' by the output Sc from the correction coefficient setting circuit 231. The operation circuit 232 receives Sc to output (1-Sc). The multiplier 234 multiplies the luminance signal Y' by the output (1-Sc) from the operation circuit 232. The adders 235r, 235g, and 235b add the output from the multiplier 234 to the outputs from the multipliers 233r, 233g, and 233b to output R", G", and B".
With this arrangement, only the color saturation can be suppressed without changing the luminance Y'.
As the output Sc from the correction coefficient setting circuit 231 is smaller, the color saturation is suppressed lower. As Sc becomes larger, the color saturation becomes higher. As for the color saturation correction coefficient Sc, when Sc=0, an achromatic color is obtained. When Sc=1, the original color saturation is preserved.
Therefore, in order to more intensively suppress the color saturation when the compression ratio of the dynamic range is high, the color saturation correction coefficient Sc must be a small value when a is small.
The input-output characteristics of the correction coefficient setting circuit 231 represent a monotone increasing function of the output Sc in response to the input α, as shown in FIG. 11. Therefore, when the compression ratio of the dynamic range is high, i.e., when α becomes smaller, Sc becomes smaller accordingly. As a result, the color saturation is intensively suppressed.
According to the fourth embodiment, the luminance of the output image signal is not changed. When the compression ratio is not high, the color saturation is not suppressed. As the compression ratio becomes higher, the color saturation is more intensively suppressed. Therefore, a more excellent color image can be displayed.
The input-output characteristics of the correction coefficient setting circuit 231 represent a linear function in FIG. 11. However, the present invention is not limited to this, and various characteristics can be used as far as they represent a monotone increasing function.
The fifth embodiment of the present invention will be described below with reference to FIGS. 12 to 14.
In the fifth embodiment, a color saturation correction coefficient is changed in accordance with the compression ratio of the dynamic range of an image.
FIG. 12 is a block diagram showing the arrangement of the fifth embodiment.
This image signal processing apparatus is constituted by a matrix circuit 9, a logarithmic converter 10, a filter 11, a DGC circuit 12a, an inverse logarithmic converter 13, delay circuits 14, 15r, 15g, and 15b, a compression coefficient setting circuit 16, multipliers 17r, 17g, and 17b, and a color saturation correction circuit 19 for performing saturation correction of outputs R', G', and B' from the multipliers 17r, 17g, and 17b.
The DGC circuit 12a is constituted by a DR coefficient setting circuit 121, a multiplier 122, a gain coefficient setting circuit 123, and an adder 124.
The color saturation correction circuit 19 receives the outputs R', G', and B' from the multipliers 17r, 17g, and 17b, an output Y' from the inverse logarithmic converter 13, and an output a from the DR coefficient setting circuit 121 in the DGC circuit 12a.
FIG. 13 is a block diagram showing the detailed arrangement of the color saturation correction circuit 19.
This color saturation correction circuit 19 is constituted by a correction coefficient setting circuit 191 for outputting a color saturation correction coefficient Sc in accordance with the luminance signal Y', an operation circuit 192 for receiving the color saturation coefficient Sc to output (1-Sc), multipliers 193r, 193g, and 193b for multiplying the compressed chrominance signals R', G', and B' by the color saturation coefficient Sc output from the correction coefficient setting circuit 191, a multiplier 194 for multiplying the output Y' from the matrix circuit 9 by the output (1-Sc) from the operation circuit 192, and adders 195r, 195g, and 195b for adding an output from the multiplier 194 to outputs from the multipliers 193r, 193g, and 193b.
The operation of each part of the fifth embodiment will be described below.
Referring to FIG. 12, a luminance signal Y is extracted from the chrominance signals R, G, and B by the matrix circuit 9 to obtain the luminance signal Y', whose dynamic range is compressed, through the logarithmic converter 10, the filter 11, the DGC circuit 12a, and the inverse logarithmic converter 13. The DGC circuit 12a multiplies a and then adds logβ. Therefore, when the output from the filter 11 is Y f , the compressed luminance signal Y' is represented by the above equation (4).
In equation (4), a is a value within a range of 0 to 1. Therefore, as the dynamic range coefficient α is smaller, the compression ratio of the dynamic range becomes higher. As the compression ratio of the dynamic range becomes higher, the color saturation must be more intensively corrected.
The compression coefficient setting circuit 16 obtains a compression coefficient C=Y'/Y from the output Y' from the inverse logarithmic converter 13 and the luminance signal Y timed by the delay circuit 14. The multipliers 17r, 17g, and 17b multiply the chrominance signals R, G, and B (timed by the delay circuits 15r, 15g, and 15b) by the compression coefficient C to obtain the chrominance signals R', G', and B' whose dynamic ranges are compressed while preserving the chromaticity. The color saturation correction circuit 19 corrects the color saturation of the chrominance signals R', G', and B' to obtain signals R", G", and B".
The operation of the color saturation correction circuit 19 as the main part of the fifth embodiment will be described below with reference to FIGS. 13 and 14.
The luminance signal Y' and the dynamic range coefficient α are input to the correction coefficient setting circuit 191. The correction coefficient setting circuit 191 calculates the color correction coefficient Sc in accordance with the following equation (5).
Sc=(1-α)×Y'+α (5)
In this case, input-output characteristics as shown in FIG. 14 are obtained. More specifically, when a changes, the magnitude of Sc changes accordingly.
The multipliers 193r, 193g, and 193b multiply the chrominance signals R', G', and B' by the output Sc from the correction coefficient setting circuit 191. The operation circuit 192 receives Sc to output (1-Sc). The multiplier 194 multiply the luminance signal Y' by the output (1-Sc) from the operation circuit 192. The adders 195r, 195g, and 195b add the output from the multiplier 194 to outputs from the multipliers 193r, 193g, and 193b to output R", G", and B".
With this arrangement, only the color saturation can be suppressed without changing the luminance Y'.
As the output Sc from the correction coefficient setting circuit 191 is smaller, the color saturation is suppressed lower. As the output Sc becomes larger, the color saturation becomes higher. As for the color saturation coefficient Sc, when Sc=0, an achromatic color is obtained, and when Sc=1, the original color saturation is preserved.
Therefore, in order to more intensively suppress the color saturation at a dark portion when the compression ratio of the dynamic range is high, the color saturation coefficient Sc must be a small value when the luminance signal and a are small.
The input-output characteristics of the correction coefficient setting circuit 191 represent a monotone increasing function of the output in response to the input, as shown in FIG. 14. For this reason, the color saturation at a dark portion is more intensively suppressed. When the input is 0, the value of Sc is equal to the dynamic range coefficient α. Therefore, when the compression ratio of the dynamic range is high, i.e., when a is small, Sc becomes small throughout the input. As a result, the color saturation is intensively suppressed throughout the input.
As described above, according to the fifth embodiment, the luminance of the output image signal is not changed, and the color saturation at a high luminance portion is not suppressed. As the luminance becomes lower, the color saturation is more intensively suppressed. Even when the compression ratio of the dynamic range is increased, the color saturation at a low luminance portion does not seem to be emphasized. When the compression ratio does not so increase, the color saturation is less intensively suppressed as a whole. As a result, a more excellent color image can be displayed.
The input-output characteristics of the correction coefficient setting circuit 191 represent a linear function in FIG. 14. However, the present invention is not limited to this, and various characteristics can be used as far as they represent a monotone increasing function.
In the fifth embodiment, when the input is 0, the value of Sc is equal to the dynamic range coefficient α. However, a function in which Sc is proportional to α or a function of higher degree of α may also be used.
The sixth embodiment in which no correction coefficient setting circuit is used will be described below with reference to FIGS. 15 and 16.
The sixth embodiment is a modification of FIG. 13 and can be replaced with the color saturation correction circuit 19 in FIG. 12.
The arrangement of the sixth embodiment will be described with reference to FIG. 15.
A luminance signal Y' is input to LUTs 196a to 196e. Outputs from the LUTs 196a to 196e are received by a selector 197. The selector 197 uses a dynamic range coefficient α as a selection signal to switch the outputs from the LUTs 196a to 196e in accordance with the value of α. Multipliers 193r, 193g, and 193b multiply chrominance signals R', G', and B' by the outputs from the LUTs 196a to 196e.
An output Sc from the selector 197 is simultaneously received by an operation circuit 192. The operation circuit 192 receives Sc to output (1-Sc). A multiplier 194 multiplies the luminance signal Y' by the output (1-Sc) from the operation circuit 192. Adders 195r, 195g, and 195b add the output from the multiplier 194 to outputs from the multipliers 193r, 193g, and 193b to output R", G", and B".
FIG. 16 is a timing chart of the input-output characteristics of the LUTs 196a to 196e. Referring to FIG. 16, characteristics represented by a line 31 correspond to the LUT 196a; 32, the LUT 196b; 33, the LUT 196c; 34, the LUT 196d; and 35, the LUT 196e. Color saturation suppression is most intensive in the LUT 196a and is weakened in an order of the LUT 196b to the LUT 196e.
The selector 197 selects an LUT for intensively suppressing the color saturation when the compression ratio of the dynamic range is high, i.e., when the value of α is small. The selector 197 selects an LUT for less intensively suppressing the color saturation when the value of α is large.
According to the sixth embodiment, the luminance of the output image signal is not changed, and the color saturation at a high luminance portion is not suppressed. As the luminance becomes lower, the color saturation is more intensively suppressed. Therefore, even when the compression ratio of the dynamic range is increased, the color saturation at a low luminance portion does not seem to be emphasized. When the compression ratio is not high, the color saturation is less intensively suppressed as a whole, so that a more excellent color image can be displayed.
The operation circuit 192 in FIG. 15 can be replaced with an LUT 198, as shown in FIG. 17.
The seventh embodiment of the present invention will be described below with reference to FIGS. 18 to 20.
FIG. 18 is a block diagram showing another arrangement of a color saturation correction circuit. FIG. 18 is a modification of FIG. 5 and almost the same as in FIG. 5. The arrangement of a color saturation correction circuit 20 is however different and, accordingly, an output Y from a delay circuit 14 is added to inputs to the color saturation correction circuit 20. The same reference numerals as in FIG. 5 denote the same parts in FIG. 18, and a detailed description thereof will be omitted.
The color saturation correction circuit 20 used in the seventh embodiment will be described with reference to FIG. 19.
The luminance signal Y input to the color saturation correction circuit 20 before compression is input to an LUT 201. Multipliers 204r, 204g, and 204b multiply chrominance signals R', G', and B' by an output Sc from the LUT 201. An operation circuit 202 receives the output Sc from the LUT 201 to output (1-Sc). A multiplier 203 multiplies a compressed luminance signal Y' by the output (1-Sc) from the operation circuit 202. Adders 205r, 205g, and 205b add the output from the operation circuit 202 to outputs from the multipliers 204r, 204g, and 204b to output R", G", and B".
The input-output characteristics of the LUT 201 represent a monotone increasing function of the output Sc in response to the input, as shown in FIG. 20. When the dynamic range of the input is wide, data having smaller values with respect to the maximum value of the data are present in output data, and the compression ratio must be increased. To the contrary, when the dynamic range is narrow, data having values smaller than a predetermined value are not present, and the compression ratio is decreased. On the other hand, a dark portion at a high compression ratio corresponds to a portion having a small input value before compression. Therefore, when the color saturation coefficient Sc is set with respect to the luminance signal Y before compression as shown in FIG. 20, the color saturation at a dark portion can be suppressed when the compression ratio is high.
As described above, according to the seventh embodiment, the color saturation coefficient can be determined regardless of the compression ratio. A simpler circuit arrangement without a complicated coefficient setting circuit can be obtained, thereby realizing adaptive color saturation correction.
In the seventh embodiment, the input-output characteristics of the LUT 201 represent a linear function. However, a function of higher degree, exponential function, or logarithmic function may also be used.
As is apparent, the operation circuit 202 may be constituted by an LUT.
FIG. 21 is a block diagram showing the eighth embodiment in which a color saturation correction circuit having an arrangement different from those of the above embodiments is used.
The eighth embodiment is a modification of FIG. 5 and has almost the same arrangement as in FIG. 5 except that the arrangement of a color saturation correction circuit 21 is changed and, accordingly, an output C=Y'/Y from a compression coefficient setting circuit 16 is added to inputs to the color saturation correction circuit 21. The same reference numerals as in FIG. 5 denote the same parts in FIG. 21, and a detailed description thereof will be omitted.
The color saturation correction circuit 21 used in the eighth embodiment will be described below with reference to FIG. 22.
The output C from the compression coefficient setting circuit 16 to the color saturation correction circuit 21 is input to an LUT 211. Multipliers 214r, 214g, and 214b multiply chrominance signals R', G', and B' by an output Sc from the LUT 211. An operation circuit 212 receives the output Sc from the LUT 211 to output (1-Sc). A multiplier 213 multiplies a compressed luminance signal Y' by the output (1-Sc) from the operation circuit 212. Adders 215r, 215g, and 215b add an output from the multiplier 213 to outputs from the multipliers 214r, 214g, and 214b to output R", G", and B".
The input-output characteristics of the LUT 211 represent a monotone decreasing function of the output Sc in response to the input C=Y'/Y, as shown in FIG. 23.
When the dynamic range of the input is wide, data having smaller values with respect to the maximum value of the data are present in output data, and the compression ratio must be increased. At this time, the compression coefficient C=Y'/Y, which is a ratio of a luminance signal Y before compression to a compressed luminance signal Y' in image data having a small value, becomes a large value. In image data having a large value, C=Y'/Y becomes a small value. To the contrary, when the dynamic range is narrow and the compression ratio is decreased, C=Y'/Y becomes a small value throughout the input.
Therefore, when the color saturation correction coefficient Sc is set with respect to C=Y'/Y, which is the ratio of the luminance signal Y before compression to the compressed luminance signal Y', as shown in FIG. 23, the color saturation at a dark portion can be suppressed at a high compression ratio.
According to the eighth embodiment, the color saturation correction coefficient can be determined in accordance with the compression ratio of each pixel, thereby realizing proper color saturation correction.
In the eighth embodiment, the input-output characteristics of the LUT 211 represent a linear function. However, a function of higher degree, exponential function, or logarithmic function may also be used.
In the eighth embodiment, the operation circuit 212 is used to obtain (1-Sc). However, for example, as shown in FIG. 24, an LUT 216 may also be used. In this case, the LUT 216 receives C=Y'/Y, and its output characteristics are set to be (1-Sc) in correspondence with the output Sc from the LUT 211. This arrangement can provide the same effect.
As shown in FIG. 25, an LUT 217 may also be used. The LUT 217 receives the output Sc from the LUT 211 and its input-output characteristics are set such that (1-Sc) is output in response to the input Sc, as shown in FIG. 8. This arrangement can provide the same effect.
The ninth embodiment in which a circuit arrangement is simplified will be described below with reference to FIGS. 26 and 27.
FIG. 26 is a block diagram showing the arrangement of the ninth embodiment. Referring to FIG. 26, the image signal processing apparatus is constituted by a matrix circuit 9, a logarithmic converter 10, a filter 11, a DGC circuit 12, an inverse logarithmic converter 13, delay circuits 14, 15r, 15g, and 15b, subtracters 221r, 221g, and 221b for subtracting an output Y from the delay circuit 14 from outputs from the delay circuits 15r, 15g, and 15b, and adders 222r, 222g, and 222b for adding an output Y' from the inverse logarithmic converter 13 to outputs from the subtracters 221r, 221g, and 221b to output R", G", and B".
The operation of the ninth embodiment will be described below with reference to FIGS. 21 and 22 of the above-described eighth embodiment.
Of chrominance signals R, G, and B, the signal R is exemplified. Referring to FIG. 21, R is compressed to become R'. Since the compression coefficient at this time is C=Y'/Y, R' is represented by the following equation.
R'=C×R=(Y'/Y)×R (6)
The R" signal after color saturation correction is represented as follows in accordance with the above equation (1)
R"=Sc×R'+(1-Sc)×Y' (7)
These equations are simplified to obtain the following equation.
R"=Sc×(Y'/Y)×R+(1-Sc)×Y' (8)
The LUT 211 in FIG. 22 is set such that a monotone decreasing function of Sc with respect to C=Y'/Y (SC=Y'/Y) can be obtained, as shown in FIG. 27. More specifically, by substituting Sc=Y'/Y into the above equation (8) and rearranging the obtained equation, the following equation can be obtained.
R"=R+Y'-Y (9)
This also applies to other chrominance signals.
On the other hand, according to the arrangement in FIG. 26, an output in accordance with equation (9) can be obtained. Therefore, the arrangement in FIG. 26 can provide exactly the same effect as in the arrangement in FIGS. 21 and 22 of the eighth embodiment when the input-output characteristics of the LUT 211 are set as shown in FIG. 27.
According to the ninth embodiment, with a very simple circuit arrangement, adaptive color saturation correction can be performed.
The tenth embodiment of the present invention will be described below with reference to FIGS. 28 to 30.
FIG. 28 is a block diagram showing the arrangement of the tenth embodiment of the present invention.
Referring to FIG. 28, the image signal processing apparatus is constituted by a photographing optical system 1, a half mirror 2, an ND filter 3, image pickup elements 4a and 4b, A/D converters 5a and 5b, an adder 6, an LUT 7, and a color separation circuit 8. This image signal processing apparatus also comprises a matrix circuit 24 for generating luminance and chrominance signals from outputs from the color separation circuit 8, a logarithmic converter 10, a filter 11, a DGC circuit 12, an inverse logarithmic converter 13, a delay circuit 14 for timing an output from the matrix circuit 24 with an output from the inverse logarithmic converter 13, and a compression coefficient setting circuit 16.
In the tenth embodiment, an input means for inputting chrominance signals R, G, and B is constituted by the matrix circuit 24.
This image signal processing apparatus is also constituted by delay circuits 25r and 25b for timing color difference signal outputs from the matrix circuit 24 with an output from the compression coefficient setting circuit 16, multipliers 26r and 26b for multiplying outputs from the delay circuits 25r and 25b by an output C from the compression coefficient setting circuit 16, a color saturation correction circuit 27 for outputting saturation-corrected signals Cr" and Cb" from outputs Cr' and Cb' from the multipliers 26r and 26b, a delay circuit 28 for timing the outputs Cr" and Cb" from the color saturation correction circuit 27 with Y', and a matrix circuit 29 for outputting saturation-corrected chrominance signals R", G", and B" from the output Y' from the delay circuit 28 and the outputs Cr" and Cb" from the color saturation correction circuit 27.
FIG. 29 is a block diagram showing the arrangement of the color saturation correction circuit 27 and the peripheral circuits.
The color saturation correction circuit 27 is constituted by a color saturation correction table 271 for receiving the compressed luminance signal component Y' to output a color saturation correction coefficient in accordance with the luminance signal Y', a delay circuit 272 for timing a color saturation correction coefficient Sc output from the color saturation correction table 271 with the compressed color difference signals Cr' and Cb' (outputs from the multipliers 26r and 26b), and multipliers 273r and 273b for multiplying the compressed color difference signals Cr' and Cb' (outputs from the multipliers 26r and 26b) by the color saturation correction coefficient Sc output from the delay circuit 272.
The operation of the tenth embodiment will be described below with reference to FIG. 28.
An object image passing through the photographing optical system 1 is divided in two directions by the half mirror 2. One of the images passes through the ND filter 3 to be focused on the image pickup element 4a, output as an analog signal, and converted into a digital signal by the A/D converter 5a. The other of the object images divided by the half mirror 2 passes through the image pickup element 4b to be converted into a digital signal by the A/D converter 5b.
At this point of time, the A/D converter 5a outputs an image signal representing that the dark portion of the object is picked up to become solid black and the bright portion is properly picked up without saturation. On the other hand, the A/D converter 5b outputs an image signal representing that the bright portion is saturated and the dark portion is picked up without becoming solid black. The adder 6 adds these image signals to obtain an image signal having information from the dark portion to the bright portion. Since the input-output characteristics of this image signal are not linear, the image signal is converted by the LUT 7 to have linear characteristics.
The color separation circuit 8 separates the image signal converted to be linear by the LUT 7 into chrominance signals R, G, and B. The matrix circuit 24 converts these signals into the luminance signal Y and the color difference signals Cr and Cb. The luminance signal Y output from the matrix circuit 24 is output as the luminance signal Y', whose dynamic range is compressed, through the logarithmic converter 10, the filter 11, the DGC circuit 12, and the inverse logarithmic converter 13.
The compression coefficient setting circuit 16 obtains a compression coefficient C=Y'/Y from the luminance signal Y timed with the output Y' from the inverse logarithmic converter 13 by the delay circuit 14. The multipliers 26r and 26b multiply the color difference signals Cr and Cb (timed by the delay circuits 25r and 25b) by the compression coefficient C to obtain the color difference signals Cr' and Cb' whose dynamic ranges are compressed while preserving the chromaticity. The color saturation correction circuit 27 corrects the color saturation of these color difference signals Cr' and Cb' to obtain the signals Cr" and Cb".
The saturation-corrected color difference signals Cr" and Cb" and the compressed luminance signal Y' timed by the delay circuit 28 are simultaneously input to the matrix circuit 29 and converted into the saturation-corrected chrominance signals R", G" and B".
The operation of the color saturation correction circuit 27 as the main part of the tenth embodiment will be described below with reference to FIG. 29.
The luminance signal component Y' input to the color saturation correction circuit 27 is input to the color saturation correction table 271. The multipliers 273r and 273b multiply the color difference signals Cr' and Cb' by the output Sc from the color saturation correction table 271.
The color difference signals are as follows.
Cr"=Sc×Cr'=Sc×C×Cr (10)
Cb"=Sc×Cb'=Sc×C×Cb (11)
The output Sc from the color saturation correction table 271 takes a value within the range of 0 to 1. As Sc is smaller, the color saturation is suppressed lower. As Sc becomes larger, the color saturation becomes higher. As for the color saturation correction coefficient Sc, when Sc=0, an achromatic color is obtained. When Sc=1, the original color saturation is preserved.
The input-output characteristics of the color saturation correction table 271 are set to represent a monotone increasing function of the output in response to the input, as shown in FIG. 30. In this case, the color saturation of a dark portion is more intensively suppressed.
As a modification of the tenth embodiment, the arrangement as shown in FIG. 31, in which saturation correction is performed before the chrominance signals are multiplied by the compression coefficient C, can provide the same effect.
More specifically, a color saturation correction table 27a is constituted by the color saturation correction table 271 and the multipliers 273r and 273b. The multipliers 273r and 273b multiply the color difference signals Cr and Cb from the delay circuits 25r and 25b by the output Sc from the color saturation correction table 271. The multipliers 26r and 26b multiply the obtained color difference signals Cr' and Cb' by the output Sc obtained from the color saturation correction table 271 through a delay circuit 30 to obtain the signals Cr" and Cb".
In the present invention, the saturation correction before multiplying the signals related to a color by the compression coefficient C, as shown in the above modification, can also be applied to the following embodiments.
As described above, according to the tenth embodiment, the luminance of the output image signal is not changed, and the color saturation at a high luminance portion is not suppressed. As the luminance becomes lower, the color saturation is more intensively suppressed. Therefore, even when the compression ratio of the dynamic range is increased, an excellent color image can be obtained while the color saturation at the low luminance portion does not seem to be emphasized.
In addition, by using the color difference signals, the circuit arrangement is further simplified as compared to the first to ninth embodiments.
The input-output characteristics of the color saturation correction table 271 represent a linear function in FIG. 30. However, the present invention is not limited to this, and various characteristics can be used as far as they represent a monotone increasing function.
The eleventh embodiment of the present invention will be described below.
FIG. 32 is a block diagram showing another arrangement of a color saturation correction circuit.
An output C from a compression coefficient setting circuit 16 and an output Sc from a color saturation correction table 271 are connected to the inputs to a multiplier 274. An output from the multiplier 274 is connected to inputs to multipliers 275r and 275b. Each of outputs Cr and Cb from delay circuits 25r and 25b is connected to the other input to a corresponding one of the multipliers 275r and 275b. Outputs from the multipliers 275r and 275b are input to a matrix circuit 29.
With this arrangement, the color difference signals Cr and Cb output from the matrix circuit 24 and passing through the delay circuits 25r and 25b are multiplied by a product Sc×C of the output C from the compression coefficient setting circuit 16 and the output Sc from the color saturation correction table 271. As a result, the outputs from the multipliers 275r and 275b become Sc×C×Cr and Sc×C×Cb, respectively. It is apparent that these outputs are Cr" and Cb" in accordance with the above equations (10) and (11).
The input-output characteristics of the color saturation correction table 271 are set to represent a monotone increasing function of the output in response to the input, as shown in FIG. 30, as in the above tenth embodiment.
The input-output characteristics of the color saturation correction table 271 represent a linear function in FIG. 30. However, the present invention is not limited to this, and various characteristics can be used as far as they represent a monotone increasing function.
According to the eleventh embodiment, the luminance of the output image signal is not changed, and the color saturation at a high luminance portion is not suppressed. As the luminance becomes lower, the color saturation is more intensively suppressed. Therefore, even when the compression ratio of the dynamic range is increased, an excellent color image can be obtained while the color saturation at a low luminance potion does not seem to be emphasized.
In the eleventh embodiment, the circuit arrangement can be further simplified as compared to the above tenth embodiment.
The twelfth embodiment in which a color saturation correction coefficient is changed in accordance with the compression ratio of the dynamic range of an image will be described below with reference to FIGS. 33 and 34.
FIG. 33 is a block diagram showing the arrangement of the twelfth embodiment.
Referring to FIG. 33, the image signal processing apparatus comprises a matrix circuit 24 for generating a luminance signal Y and color difference signals Cr and Cb from signals R, G, and B, a logarithmic converter 10, a filter 11, a DGC circuit 12a, an inverse logarithmic converter 13, a delay circuit 14, and a compression coefficient setting circuit 16. This image signal processing apparatus is also constituted by delay circuits 25r and 25b, multipliers 26r and 26b, and a color saturation correction circuit 31 for performing saturation correction from outputs Cr' and Cb' from the multipliers 26r and 26b.
As described above, the DGC circuit 12a is constituted by a DR coefficient setting circuit 121, a multiplier 122, a gain coefficient setting circuit 123, and an adder 124.
The color saturation correction circuit 31 is constituted by a color saturation correction table 311 and multipliers 312r and 312b. The color saturation correction circuit 31 receives the outputs Cr' and Cb' from the multipliers 26r and 26b and an output a from the DR coefficient setting circuit 121 in the DGC circuit 12a to output a color saturation correction coefficient Sc in accordance with the dynamic range coefficient α. The multipliers 312r and 312b multiply the compressed color difference signals Cr' and Cb' by the color saturation correction coefficient Sc output from the color saturation correction table 311.
The operation of the twelfth embodiment will be described below.
The luminance signal Y is extracted by the matrix circuit 24 to obtain a luminance signal Y', whose dynamic range is compressed, through the logarithmic converter 10, the filter 11, the DGC circuit 12a, and the inverse logarithmic converter 13. The DGC circuit 12a multiplies α and then adds logβ. Therefore, when the output from the filter is Y f , the compressed luminance signal Y' is represented by the above equation (4).
In this case, α is a value within a range of 0 to 1. Therefore, as the dynamic range coefficient α is smaller, the compression ratio of the dynamic range becomes higher. As the compression ratio of the dynamic range is increased, the color saturation must be intensively corrected. The compression coefficient setting circuit 16 obtains a compression coefficient C=Y'/Y from the output Y' from the inverse logarithmic converter 13 and the luminance signal Y timed by the delay circuit 14. The multipliers 26r and 26b multiply the color difference signals Cr and Cb (timed by the delay circuits 25r and 25b) by the compression coefficient C to obtain the color difference signals Cr' and Cb' whose dynamic ranges are compressed while the color saturation is preserved. The color saturation correction circuit 31 corrects the color saturation of these color difference signals to obtain signals Cr" and Cb".
The operation of the color saturation correction circuit 31 as the main part of the twelfth embodiment will be described below. The dynamic range coefficient α is input to the color saturation correction table 311. The color saturation correction table 311 outputs the color saturation correction coefficient Sc in accordance with the input-output characteristics as shown in FIG. 34. As a changes, the magnitude of Sc changes accordingly. The multipliers 312r and 312b multiply the chrominance signals Cr' and Cb' by the output Sc from the color saturation correction table 311 to be output as Cr" and Cb".
In this case, only the color saturation can be suppressed without changing the luminance Y'.
The output Sc from the color saturation correction table 311 takes a value within a range of 0 to 1. As Sc is smaller, the color saturation is suppressed lower. As Sc becomes larger, the color saturation becomes higher. As for the color saturation correction coefficient Sc, when Sc=0, an achromatic color is obtained when Sc=1, the original color saturation is preserved. Therefore, in order to more intensively suppress the color saturation at a high compression ratio of the dynamic range, the color saturation correction coefficient Sc must be a small value when α is small.
The input-output characteristics of the color saturation correction table 311 are set to represent a monotone increasing function of the output Sc in response to the input a, as shown in FIG. 34. In this case, when the compression ratio of the dynamic range is high, i.e., when a becomes smaller, Sc becomes smaller accordingly. As a result, the color saturation is intensively suppressed.
The input-output characteristics of the color saturation correction table 311 represent a linear function in FIG. 34. However, the present invention is not limited to this, and various characteristics can be used as far as they represent a monotone increasing function.
According to the twelfth embodiment, the luminance of the output image signal is not changed. When the compression ratio is not high, the color saturation is not suppressed. As the compression ratio becomes higher, the color saturation is more intensively suppressed. Therefore, a more excellent color image can be displayed.
In addition, by using the color difference signals, the circuit arrangement can be simplified.
The thirteenth embodiment of the present invention will be described below.
FIG. 35 is a block diagram showing the arrangement of the thirteenth embodiment in which a color saturation correction circuit having another arrangement is used. This is a modification of the image signal processing apparatus shown in FIG. 33.
Referring to FIG. 35, an output C from the compression coefficient setting circuit 16 and an output Sc from the color saturation correction table 311 are connected to inputs to a multiplier 313. An output from the multiplier 313 is connected to the inputs to multipliers 314r and 314b. Each of outputs Cr and Cb from delay circuits 25r and 25b is connected to the other input to a corresponding one of the multipliers 314r and 314b. Outputs from the multipliers 314r and 314b are input to a matrix circuit 29.
With this arrangement, the color difference signals Cr and Cb output from the matrix circuit 24 and passing through the delay circuits 25r and 25b are multiplied by a product Sc×C of an output C from the compression coefficient setting circuit 16 and an output Sc from the color saturation correction table 311. As a result, the outputs from the multipliers 314r and 314b become Sc×C×Cr and Sc×C×Cb, respectively. It is apparent that these outputs are Cr" and Cb" in accordance with the above equations (10) and (11).
The input-output characteristics of the color saturation correction table 311 are set to present a monotone increasing function of the output in response to the input, as in the above twelfth embodiment, as shown in FIG. 34. In this case, when the compression ratio of the dynamic range is high, i.e., when a becomes smaller, Sc becomes smaller accordingly. As a result, the color saturation is intensively suppressed.
The input-output characteristics of the color saturation correction table 311 represent a linear function in FIG. 34. However, the present invention is not limited to this, and various characteristics can be used as far as they represent a monotone increasing function.
According to the thirteenth embodiment, the luminance of the output image signal is not changed. When the compression ratio is not high, the color saturation is not suppressed. As the compression ratio becomes higher, the color saturation is more intensively suppressed. Therefore, a more excellent color image can be displayed.
In the thirteenth embodiment, the circuit arrangement is further simplified as compared to the above twelfth embodiment.
The fourteenth embodiment of the present invention will be described below.
FIG. 36 is a block diagram showing the fourteenth embodiment in which a color saturation correction circuit having another arrangement is used. This is another modification of the image signal processing apparatus shown in FIG. 33. It is almost the same as the processing section in FIG. 33 except for the arrangement of the color saturation correction circuit.
Referring to FIG. 36, a color saturation correction circuit 32 is constituted by a correction coefficient setting circuit 321, a delay circuit 322, and multipliers 323r and 323b.
The correction coefficient setting circuit 321 outputs a correction coefficient Sc from an output α from a DR coefficient setting circuit 121 and an output Y from an inverse logarithmic converter 13. The delay circuit 322 times outputs Cr' and Cb' from the multipliers 26r and 26b with the output Sc from the correction coefficient setting circuit 321. The multipliers 323r and 323b multiply the outputs Cr' and Cb' from the multipliers 26r and 26b by the correction coefficient Sc.
The arrangement and operation of the color saturation correction circuit 32 used in the fourteenth embodiment will be described below with reference to FIG. 36.
A luminance signal Y' and a dynamic range coefficient α are input to the correction coefficient setting circuit 321. The correction coefficient setting circuit 321 calculates the color saturation correction coefficient Sc in accordance with equation (12).
Sc=(1-α)×Y'+α (12)
This represents input-output characteristics as shown in FIG. 37. As Y' and α change, the magnitude of Sc changes accordingly.
The output Sc from the correction coefficient setting circuit 321 is timed by the delay circuit 322. The multipliers 323r and 323b then multiply the color difference signals Cr' and Cb' by the output Sc to output Cr" and Cb". The output Sc from the correction coefficient setting circuit 321 takes a value within a range of 0 to 1. As Sc is smaller, the color saturation is suppressed lower. As Sc becomes larger, the color saturation becomes higher. When Sc=0, an achromatic color is obtained. When Sc=1, the original color saturation is preserved.
The input-output characteristics of the correction coefficient setting circuit 321 represent a monotone increasing function of the output in response to the input. The color saturation at a dark portion is more intensively suppressed. In addition, when the input is 0, the value of Sc is equal to the dynamic range coefficient α. For this reason, when the compression ratio of the dynamic range is high, i.e., when a becomes smaller, Sc becomes smaller accordingly throughout the input. As a result, the color saturation is intensively suppressed throughout the input.
The input-output characteristics of the correction coefficient setting circuit 321 represent a linear function in FIG. 37. However, the present invention is not limited to this, and various characteristics can be used as far as they represent a monotone increasing function.
In the fourteenth embodiment, when the input is 0, the value of Sc is equal to the dynamic range coefficient α. However, a function in which Sc is proportional to α or a function of higher degree of α may also be used.
According to the fourteenth embodiment, the luminance of the output image signal is not changed, and the color saturation at a high luminance portion is not suppressed. As the luminance becomes lower, the color saturation is more intensively suppressed. Therefore, even when the compression ratio of the dynamic range is increased, the color saturation at a low luminance portion does not seem to be emphasized. When the compression ratio is not so high, the color saturation is less intensively suppressed as a whole. As a result, a more excellent color image can be displayed.
In addition, by using the color difference signals, the circuit arrangement is simplified.
The fifteenth embodiment of the present invention will be described below.
FIG. 38 is a block diagram showing the arrangement of the fifteenth embodiment of the present invention in which a color correction circuit having another arrangement is used. This is a modification of the image signal processing apparatus shown in FIG. 36.
Referring to FIG. 38, an output C from a compression coefficient setting circuit 16 and an output Sc from a correction coefficient setting circuit 321 are connected to inputs to a multiplier 324. An output from the multiplier 324 is connected to inputs to multipliers 325r and 325b. Each of outputs Cr and Cb from delay circuits 25r and 25b is connected to the other input to a corresponding one of the multipliers 325r and 325b. Outputs from the multiplier 325r and 325b are connected to an input to a matrix circuit 29.
With this arrangement, the color difference signals Cr and Cb output from the matrix circuit 24 and passing through the delay circuit 25r and 25b are multiplied by a product Sc×C of the output C from the compression coefficient setting circuit 16 and the output Sc from the correction coefficient setting circuit 321. As a result, the outputs from the multipliers 325r and 325b become Sc×C×Cr and Sc×C×Cb, respectively. It is apparent that these outputs are Cr" and Cb" in accordance with the above equations (10) and (11).
The input-output characteristics of the correction coefficient setting circuit 321 represent a monotone increasing function of the output in response to the input, as in the above fourteenth embodiment, as shown in FIG. 37. Therefore, the color saturation at a dark portion is more intensively suppressed. In addition, when the input is 0, the value of Sc is equal to a dynamic range coefficient α. For this reason, when the compression ratio of the dynamic range is high, i.e., when α becomes smaller, Sc becomes smaller accordingly throughout the input. As a result, the color saturation is intensively suppressed throughout the input.
In the fifteenth embodiment, when the input is 0, the value of Sc is equal to the dynamic range coefficient α. However, a function in which Sc is proportional to α or a function of higher degree of α may also be used.
As described above, according to the fifteenth embodiment, the luminance of the output image signal is not changed, and the color saturation at a high luminance portion is not suppressed. As the luminance becomes lower, the color saturation at a low luminance portion is more intensively suppressed. Therefore, even when the compression ratio of the dynamic range is increased, the color saturation at a low luminance portion does not seem to be emphasized. When the compression ratio is not so increased, the color saturation is less intensively suppressed as a whole. As a result, a more excellent color image can be displayed.
In the fifteenth embodiment, the circuit arrangement is simplified as compared to the above fourteenth embodiment.
The sixteenth embodiment of the present invention will be described below.
FIG. 39 is a block diagram showing the sixteenth embodiment of the present invention in which the image signal processing apparatus in FIG. 29 is modified and a color saturation correction circuit having another arrangement is used. The arrangement in FIG. 39 is almost the same as in FIG. 29 except for the arrangement of the color saturation correction circuit.
Referring to FIG. 39, a color saturation correction circuit 33 is constituted by a color saturation correction table 331 for outputting a correction coefficient Sc from an output Y from a delay circuit 14, a delay circuit 332 for timing outputs Cr' and Cb' from multipliers 26r and 26b with the output Sc from the color saturation correction table 331, and multipliers 333r and 333b for multiplying the outputs Cr' and Cb' from the multipliers 26r and 26b by the correction coefficient Sc.
With this arrangement, the luminance signal Y before compression is input to the color saturation correction table 331. The multipliers 333r and 333b multiply the color difference signals Cr' and Cb' by Sc output from the color saturation correction table 331 and passing through the delay circuit 332 to output Cr" and Cb".
FIG. 40 is a timing chart of the input-output characteristics of the color saturation correction table 331. As shown in FIG. 40, this characteristics represent a monotone increasing function of the output in response to the input.
In this embodiment, the input-output characteristics of the color saturation correction table 331 represent a linear function. However, a function of higher degree, exponential function, or logarithmic function may also be used.
When the dynamic range of the input is wide, data having smaller values with respect to the maximum value of the data are present in output data, and the compression ratio must be increased. To the contrary, when the dynamic range is narrow, data having values smaller than a predetermined value are not present, and the compression ratio is decreased. On the other hand, a dark portion at a high compression ratio corresponds to a portion having a small input value before compression. Therefore, when the color saturation correction coefficient Sc with respect to the luminance signal Y before compression is set as shown in FIG. 40, the color saturation at a dark portion can be suppressed when the compression ratio is high.
According to the sixteenth embodiment, the color saturation correction coefficient can be determined regardless of the compression ratio. A simple circuit arrangement without a complicated coefficient setting circuit can be obtained, thereby realizing adaptive color saturation correction.
In addition, by using the color difference signals, the circuit arrangement is further simplified.
The seventeenth embodiment of the present invention will be described.
FIG. 41 is a block diagram showing the seventeenth embodiment of the present invention in which the image signal processing apparatus in FIG. 38 is modified and a color saturation correction circuit having another arrangement is used.
Referring to FIG. 41, an output C from a compression coefficient setting circuit 16 and an output Sc from a color saturation correction table 331 are connected to inputs to a multiplier 334. An output from the multiplier 334 is connected to inputs to a multipliers 335r and 335b. Each of outputs Cr and Cb from delay circuit 25r and 25b is connected to the other input to a corresponding one of the multipliers 335r and 335b. Outputs from the multipliers 335r and 335b are input to a matrix circuit 29.
With this arrangement, the color difference signals Cr and Cb output from the matrix circuit 24 and passing through the delay circuit 25r and 25b are multiplied by a product Sc×C of the output C from the compression coefficient setting circuit 16 and the output Sc from the correction coefficient setting circuit 321. As a result, the outputs from the multipliers 325r and 325b become Sc×C×Cr and Sc×C×Cb, respectively. It is apparent that these outputs are Cr" and Cb" in accordance with the above equations (10) and (11).
When the dynamic range of the input is wide, data having smaller values with respect to the maximum value of the data are present in output data, and the compression ratio must be increased. To the contrary, when the dynamic range is narrow, data having values smaller than a predetermined value are not present, and the compression ratio is decreased. On the other hand, a dark portion at a high compression ratio corresponds to a portion with a small input value before compression. Therefore, when the color saturation correction coefficient Sc with respect to the luminance signal Y before compression is set as shown in FIG. 40, the color saturation at a dark portion can be suppressed when the compression ratio is high.
According to the seventeenth embodiment, the luminance of the output image signal is not changed. When the compression ratio is not high, the color saturation is not suppressed. As the compression ratio becomes higher, the color saturation is more intensively suppressed. Therefore, a more excellent color image can be displayed.
In the seventeenth embodiment, the circuit arrangement is further simplified as compared to the sixteenth embodiment.
The eighteenth embodiment of the present invention will be described below.
FIG. 42 is a block diagram showing the eighteenth embodiment of the present invention in which the image signal processing apparatus in FIG. 29 is modified. The arrangement of the image signal processing apparatus in FIG. 42 is almost the same as in FIG. 29 except for the arrangement of a color saturation correction circuit.
A color saturation correction circuit 34 is constituted by a color saturation correction table 341 for outputting a correction coefficient Sc from an output C from a compression coefficient setting circuit 16, a delay circuit 342 for timing outputs Cr' and Cb' from multipliers 26r and 26b with the output Sc from the color saturation correction table 341, and multipliers 343r and 343b for multiplying the output Cr' and Cb' from the multipliers 26r and 26b by the correction coefficient Sc.
With this arrangement, the output C from the compression coefficient setting circuit 16 is input to the color saturation correction table 341. The multipliers 343r and 343b multiply the color difference signals Cr' and Cb' by Sc output from the color saturation correction table 341 and passing through the delay circuit 342 to output Cr" and Cb".
The input-output characteristics of the color saturation correction table represent a monotone decreasing function of the output Sc in response to the input C=Y'/Y, as shown in FIG. 43.
When the dynamic range of the input is wide, data having smaller values with respect to the maximum value of the data are present in output data, and the compression ratio must be increased. At this time, the compression coefficient C=Y'/Y, which is a ratio of a luminance signal Y before compression and a compressed luminance signal Y' in image data having a small value, becomes a large value. In image data having a large value, c=Y'/Y becomes a small value. To the contrary, when the dynamic range is narrow and the compression ratio is decreased, C=Y'/Y becomes a small value throughout the input. Therefore, when the color saturation correction coefficient Sc is set with respect to C=Y'/Y, which is the ratio of the luminance signal Y before compression to the compressed luminance signal Y', as shown in FIG. 15, the color saturation at a dark portion can be suppressed at a high compression ratio.
In this embodiment, the input-output characteristics of the color saturation correction table 341 represent a linear function. However, a function of higher degree, exponential function, or logarithmic function may also be used.
As described above, according to the eighteenth embodiment, the color saturation correction coefficient can be determined regardless of the compression ratio, thereby realizing proper color saturation correction.
In addition, in the eighteenth embodiment, by using the color difference signals, the circuit arrangement is further simplified.
The nineteenth embodiment of the present invention will be described below.
FIG. 44 is a block diagram showing the arrangement of the nineteenth embodiment of the present invention in which the image signal processing apparatus in FIG. 42 is modified.
An output C from a compression coefficient setting circuit 16 is input to a delay circuit 344 to be timed with an output Sc from a color saturation correction table 341. The output C from the delay circuit 344 and the output Sc from the color saturation correction table 341 are connected to inputs to a multiplier 345. An output from the multiplier 345 is connected to inputs to multipliers 346r and 346b. Each of outputs Cr and Cb from delay circuits 25r and 25b is connected to the other input to a corresponding one of the multipliers 346r and 346b. The outputs from the multipliers 346rand 346b are input to a matrix circuit 29.
With this arrangement, the color difference signals Cr and Cb output from the matrix circuit 24 and passing through the delay circuit 25r and 25b are multiplied by a product Sc×C of the output C from the compression coefficient setting circuit 16 and the output Sc from the color saturation correction table 341. As a result, the outputs from the multipliers 26r and 26b become Sc×C×Cr and Sc×C×Cb, respectively. It is apparent that these outputs are Cr" and Cb" in accordance with the above equations (10) and (11).
The input-output characteristics of the color saturation correction table 341 represent a monotone decreasing function of the output Sc in response to the input C=Y'/Y, as shown in FIG. 43.
When the dynamic range of the input is wide, data having smaller values with respect to the maximum value of the data are present in output data, and the compression ratio must be increased. At this time, the compression coefficient C=Y'/Y, which is a ratio of a luminance signal Y before compression and a compressed luminance signal Y' in image data having a small value, becomes a large value. In image data having a large value, C=Y'/Y becomes a small value. To the contrary, when the dynamic range is narrow and the compression ratio is decreased, C=Y'/Y becomes a small value throughout the input. Therefore, when the color saturation correction coefficient Sc is set with respect to C=Y'/Y, which is the ratio of the luminance signal Y before compression to the compressed luminance signal Y' as shown in FIG. 43, the color saturation at a dark portion can be suppressed at a high compression ratio.
In this embodiment, the input-output characteristics of the color saturation correction table 341 represent a linear function. However, a function of higher degree, exponential function, or logarithmic function may also be used.
As described above, according to the nineteenth embodiment, the color saturation correction coefficient can be determined in accordance with the compression ratio of each pixel, thereby realizing proper color saturation correction.
In the nineteenth embodiment, the circuit arrangement is further simplified as compared to the above eighteenth embodiment.
The twentieth embodiment in which a circuit arrangement is further simplified will be described below with reference to FIG. 45.
FIG. 45 is a block diagram showing the arrangement of the twentieth embodiment of an image signal processing apparatus of the present invention.
This image signal processing apparatus comprises a matrix circuit 24, a logarithmic converter 10, a filter 11, a DGC circuit 12, an inverse logarithmic converter 13, a delay circuit 14, and a compression coefficient setting circuit 16.
This apparatus is also constituted by a color saturation correction table 351 for receiving an output C from the compression coefficient setting circuit 16 to output α product of a color saturation correction coefficient Sc and the compression coefficient C, delay circuits 25r and 25b for timing the output from the color saturation correction table 351 with the color difference signal outputs from the matrix circuit 24, multipliers 352r and 352b for multiplying outputs Cr and Cb from the delay circuits 25r and 25b by the output from the color saturation correction table 351, a delay circuit 28 for timing an output Y' from the inverse logarithmic converter 13 with outputs Cr" and Cb" from the multipliers 352r and 352b, and a matrix circuit 29 for outputting chrominance signals R", G", and B" from the luminance signal Y' output from the delay circuit 28 and the color difference signals Cr" and Cb" output from the multipliers 352r and 352b. In the twentieth embodiment, the arrangement from a photographing optical system 1 to a color separation circuit 8 (none are shown) arranged before the matrix circuit 24 is the same as in the image signal processing apparatus in FIG. 28, and a detailed description thereof will be omitted.
In the twentieth embodiment, the input-output characteristics of the color saturation correction table 351 are set as shown in FIG. 46. In this case, the output is C×Sc in response to the input C (Sc is defined by the characteristics in FIG. 43). Therefore, the outputs from the multipliers 352r and 352b become Cr×C×Sc=Cr" and Cb×C×Sc=Cb", respectively, which are the same as in the above eighteenth embodiment.
According to the twentieth embodiment, with a very simple circuit arrangement, the color saturation correction coefficient can be determined in accordance with the compression ratio of each pixel, thereby realizing proper color saturation correction.
The twenty-first embodiment in which no multiplier is used will be described with reference to FIG. 47.
FIG. 47 is a block diagram showing the arrangement of the twenty-first embodiment of an image signal processing apparatus of the present invention.
Referring to FIG. 47, this image signal processing apparatus comprises a matrix circuit 24, a logarithmic converter 10, logarithmic converters 36r and 36b for logarithmically converting color difference signals Cr and Cb, a filter 11 for suppressing low-frequency components of a logarithmically converted luminance signal logY, a DGC circuit 12, a delay circuit 14 for timing the output logY from the logarithmic converter 10 with an output logY' from the DGC circuit 12, and a compression coefficient setting circuit 37 for outputting a difference between the output logY from the delay circuit 14 and the output logY' from the DGC circuit 12, i.e., logY-logY'=log(Y'/Y)=logC.
This apparatus also comprises a color saturation correction table 353 for outputting a coefficient obtained by adding a color saturation correction coefficient to the output logC from the compression coefficient setting circuit 37, delay circuits 25r and 25b for timing the outputs from the logarithmic converters 36r and 36b with the output from the color saturation correction table 353, adders 354r and 354b for adding the output from the color saturation correction table 353 to the outputs from the delay circuits 25r and 25b, and inverse logarithmic converters 38r and 38b for performing inverse logarithmic conversion of the outputs from the adders 354r and 354b.
This apparatus also comprises a delay circuit 28 for timing the output logY' from the DGC circuit 12 with the outputs from the adders 354r and 354b, an inverse logarithmic converter 13, and a matrix circuit 29 for outputting chrominance signals R", G" and'B" from the luminance signal Y' output from the inverse logarithmic converter 13 and the color difference signals Cr" and Cb" output from the inverse logarithmic converters 38r and 38b.
In the twenty-first embodiment, the compression coefficient is output in the form of logarithm (logC). Accordingly, the output from the color saturation correction table 353 also takes the form of logarithm {log(C×Sc)}. The adders 354r and 354b add the output from the color saturation correction table 353 to the color difference signals in the form of logarithm. The inverse logarithmic converters 38r and 38b perform inverse logarithmic conversion of the outputs from the adders 354r and 354b to obtain the saturation-corrected color difference signals Cr" and Cb". The logarithmic converter or inverse logarithmic converter can be easily constituted by a memory such as a ROM or RAM. Since no multiplier is used, the circuit arrangement is simplified.
As described above, according to the twenty-first embodiment, with a very simple circuit arrangement, the color saturation correction coefficient can be determined in accordance with the compression ratio of each pixel, thereby realizing proper color saturation correction.
The image signal processing apparatus of the present invention is not limited to the above-described embodiments. As is apparent, the present invention can be applied to combinations or modifications of the embodiments as well as any apparatus incorporating the concept of the present invention.
As has been described above, according to the present invention, color saturation is adaptively corrected in accordance with information obtained from image data. Therefore, even when the compression ratio variously changes upon compression of the dynamic range of a color image, an excellent image can be displayed with a natural color tone from low luminance data to high luminance data.
Additional embodiments of the present invention will be apparent to those skilled in the art from consideration of the specification and practice of the present invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope of the present invention being indicated by the following claims.
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An input section receives an image signal including signals related to colors to output at least a luminance signal component of the image signal. A compressing section compresses the dynamic range of the luminance signal component from the input section. A setting section obtains a compression coefficient from a relationship between the luminance signal component whose dynamic range is compressed by the compressing section and the luminance signal component from the input section. An operating section executes an operation for compressing dynamic ranges of the signals related to colors included in the image signal in accordance with the compression coefficient obtained by the setting section. A correcting section substantially corrects the color saturation of the signals related to a color included in the image signal while preserving the luminance of the image signal such that the color saturation is more intensively suppressed as the luminance becomes lower.
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This application is a division, of application Ser. No. 07/336,065, filed Apr. 11, 1989 U.S. Pat. No. 5,113,127.
FIELD OF THE INVENTION
The present invention relates to battery chargers. More particularly, it relates to battery chargers employing current converters of the blocking oscillator type. The blocking oscillator may receive energy from a wide variety of sources of alternating or direct current and serves to convert such input energy suitable for charging one or more storage cells.
BACKGROUND OF THE INVENTION
Storage batteries, especially of the nickel-cadmium type, are widely used as power sources for portable tools and appliances even where power from public utilities may be readily accessible. Batteries of relatively small capacity are used in such devices so that battery size and weight will not detract from the convenience of use and portability of the device in which the battery is installed. The small capacity of such batteries requires that they be frequently recharged, often after each use of the device in which they are installed, so that the device will be able to deliver full service at any needed time.
It is normal commercial practice, therefore, to include a battery charger with each storage battery operated device sold. Such chargers are of the simplest possible circuit design intended to receive input power only from a source of specified characteristics and to deliver charging current only to the battery contained in the device with which it is sold. The lack of universality of such chargers impairs the convenience of battery operated devices. If the device is to be used in an area where the utility power differs from that of the area in which the device was originally designed or power differs from that of the area in which the device was originally sold, it is necessary to replace the charger. If the charger designed for use with a particular device is misplaced or damaged, often a charger designed for another device cannot be substituted for the original charger.
A variety of battery charger circuits have been developed in response to these problems. Chargers of the type using a blocking oscillator as a current converter are of interest herein. In this type charger the charging current supplied to the battery is, in general, dependent upon a threshold set by a sensing part of the circuitry. This threshold is independent of the supply voltage in large part since it is designed to sense current. Therefore, this type of charger can be designed to accept input power from sources having a wide range of voltages while still delivering substantially constant charging current to the battery.
PRIOR ART
U.S. Pat. No. 4,376,263, issued Mar. 8, 1983, discloses a blocking oscillator type battery charger having a two-winding transformer, two switching transistors and capacitive feedback from the transformer secondary to the primary transistor to provide regenerative action. The oscillator is free-running and continues to oscillate when the battery is connected in the charging circuit. The battery under charge is not transformer isolated from the input power circuit.
U.S. Pat. No. 4,710,695, issued Dec. 1, 1987, discloses a battery charger of the blocking oscillator type which includes a three-winding transformer (FIG. 8). The battery under charge is isolated from the input power supply by the third transformer winding. The oscillator circuit includes a switching transistor which receives a forward bias through a resistor directly connected between the power supply and the base of the switching transistor. The oscillator is free running and does not depend upon the presence of a battery to maintain oscillation. A smoothing capacitor is connected across the battery being recharged.
It is an object of the present invention to provide a battery charger capable of operating with a wide variety of input power sources.
It is another object of the invention to provide a battery charger capable of charging a plurality of batteries simultaneously.
It is a further object of the invention to provide a battery charger in which the battery or batteries under charge are isolated from direct connection to the input power supply, for safety purposes.
It is still another object of the invention to provide a battery charger which is highly efficient in operation and which consumes power only when one or more batteries capable of accepting a charge are connected in the charging circuit thereof.
These and other objects and advantages of the invention are to become apparent as a complete understanding of the invention is gained through the complete description of the invention as set out below, reference being made to the accompanying figures of drawing wherein like reference numerals designate like circuit components.
SUMMARY OF THE INVENTION
The battery charger of the invention is of the driven blocking oscillator type. The driven oscillator includes a switching transistor, a feedback transistor and a three-winding transformer. The switching transistor controls current flow from the power supply through the transformer primary winding. The transformer secondary winding is phased with respect to the primary to provide positive feedback to the switching transistor. The sense transistor detects the current, and in conjunction with feedback circuitry, insures a rapid transition of the switching transistor from a conducting to a non-conducting state. The battery or batteries under charge receive charging current from the transformer tertiary winding which isolates the battery or batteries being charged from the power supply. The network connected between the secondary winding and the switching transistor is such that the switching transistor is retriggered only through a specific feedback action between the transformer tertiary and secondary windings, which action is dependent upon the presence of a chargeable battery in the circuit of the transformer tertiary winding.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a first exemplary embodiment of a battery charger of the present invention.
FIG. 2 is a schematic diagram of a second exemplary embodiment of the battery charger of the present invention in which a SCR is used instead of a sense transistor.
FIG. 3 is a schematic diagram of a third exemplary embodiment of a battery charger of the present invention.
FIG. 4 is a schematic diagram of a multiple station arrangement for charging a plurality of batteries from the battery chargers of FIGS. 1-3 with means for cutting off charging current to the individual batteries whenever each respective battery becomes fully charged.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The battery charger circuit of the invention, as illustrated in FIG. 1, includes a source 10 of input power which may be an a.c. or d.c. source ranging in voltage from about 36 v. to about 230 v. The source 10 supplies current to a rectifier bridge 11 through an inductor 12 connected in series to the source 10 via a resistor 13 and a switch 14. The positive output terminal of the bridge 11 is connected to a B+ supply line 15 and the negative output terminal of the bridge 11 is connected to a return line 16. A filter capacitor 17 is connected across the lines 15 and 16. A terminal 18 of a primary winding 20 of a three-winding transformer 21 is connected to the B+ line 15. A terminal 22 of the primary winding 20 is connected to the collector of a switching transistor 23, the emitter of which is connected to the return line 16 through a low value resistor 24. A terminal 25 of transformer secondary winding 26 is connected to the return line 16. A terminal 27 of the secondary winding 26 is connected through resistor 28 to the base of the transistor 23. The collector of a sense transistor 30 is connected to the base of transistor 23 and the emitter thereof is connected to the return line 16. Resistors 31 and 32, connected in series between the line 15 and the base of the transistor 30, together with a resistor 33 and the resistor 24, form a voltage divider for biasing the transistor 30. A feedback capacitor 34 is connected between the junction of the resistors 31 and 32 and the collector of transistor 23.
The terminals 18 and 27 of the primary and secondary windings of the transformer 21 are of like phase to provide a regenerative action, as is described hereinbelow.
A terminal 35 of the tertiary winding of transformer 21 is connected to the female terminal of a first output connector 36. A terminal 37 of the transformer tertiary winding is connected to the cathode of a diode 38, the anode of which is connected to the female terminal of a second output connector 40. The diode 38, which has an intrinsic capacitance between its anode and cathode, may be paralleled by a connected capacitor 42 for reasons described hereinbelow. In realized embodiments, it has been found that a 1N4007 diode may be used as the diode 38 even without the capacitor 42.
One or more of batteries 41a-41n to be charged are connected in series, with the positive terminal of the first battery 41a of the series connected to the male contact of the connector 36 and the negative terminal of the last battery 41n in the series connected to the male contact of the connector 40. Connection of the batteries to be charged to the charger may be facilitated by the use of a multi-station charging system as described in U.S. Pat. No. 4,591,777 for "Multi-Station Modular Charging System for Cordless Tools and Appliances", issued May 27, 1988 and assigned to the assignee of the present invention. It is to be understood that the term battery, as used herein, includes single cell batteries, multiple cell batteries and battery packs.
A Zener diode 43 and a surge-protecting diode 44 are connected in series across the primary winding 20 of the transformer 21, their respective anodes being connected to the respective terminals 18 and 22 of the primary winding. The diodes 43 and 44 serve to protect the switching transistor 23 from large voltage pulses which may appear across the primary winding 20.
The charger circuit of FIG. 1 operates as a driven blocking oscillator. At start-up, the transistors 23 and 30 are initially non-conducting. Upon the application of power from the source 10 a positive voltage pulse is conducted by capacitor 34 to the primary winding 20 and the transistor 23, due to its base-collector capacitance, begins to conduct. Then the current into the primary winding 20 induces a positive voltage at terminal 27 of the secondary winding of transformer 21 which reinforces the signal that appears at the base of transistor 23 and the collector of transistor 30. This regenerative action continues and the transistor 23 conducts more heavily, raising the voltage at the emitter thereof which is applied through resistor 33 to the base of the transistor 30. The resistor 24 provides a voltage at its end remote from the return line 16 proportional to the current flowing in the primary winding 20. The resistor 33 provides an additional drop due to two effects. There is a small voltage proportional to the supply voltage due to the voltage divider comprising the resistors 31, 32, 33 and 24. In addition there is a voltage component due to any a.c. components in the signal at the collector of the transistor 23. During the regenerative phase, only the small component proportional to line voltage appears across the resistor 33. This adds to the voltage across the resistor 24 to produce the base voltage for the sense transistor 30. When this voltage, predominantly made up of the drop across the resistor 24 proportional to the current in the primary winding 20 reaches about 0.6 volts, the transistor 30 begins to conduct diverting base drive away from the transistor 23. This tends to decrease the primary current, by inhibiting the regeneration, causing the voltage at the collector of the transistor 23 to abruptly rise. The capacitor 34 couples this sharp rise into the divider which affects the resistor 33, with the net result being that the voltage at the base of transistor 30 experiences a positive jump. This causes the transistor 30 to conduct more heavily, further cutting the base drive to the transistor 23 and, consequently, speeding the decrease of current in the primary winding 20. The net result is a greatly enhanced shut-off of the primary current, precipitating the commutation of the voltages on the windings of the transformer 21 to shut down conduction on the primary side and to initiate conduction on the tertiary side, that is in the tertiary winding. The threshold of switching occurs due to the transistor 30 sensing predominantly the current in the primary winding 20. In this way, constant current is maintained over supply voltage. Since there is a small change in peak current proportional to supply voltage due to switching dynamics, the small voltage component proportional to supply voltage across the resistor 33 is added to just counteract this effect, resulting in excellent current regulation against variations in supply.
Looking now at the events in the tertiary winding of the transformer 21, as current flows into the terminal 18 of the transformer primary winding 20, a negative voltage is induced and appears at the terminal 37 of the transformer tertiary winding. Assuming one or more batteries (or battery packs) 41a-41n to be in place, current flow out of the negative terminal of battery 41n is blocked by the diode 38. When the current in the primary winding 20 starts to collapse, a positive voltage is induced at the terminal 35 of the transformer tertiary winding. Charging current can now flow into the positive terminal of battery 41a. The charging current continues to flow until the transformer flux drops to a level insufficient to support a positive voltage across the series combination of the diode 38 and the batteries 41a-41n. At that time a new oscillation cycle is initiated as stated below.
When the voltage across terminals 35 and 37 becomes less positive than the voltage of the batteries 41a-41n (or only one battery if only one is in circuit) the battery or batteries commence to discharge into the terminal 35 of the tertiary winding. No significant discharge current is expected to flow because of the blocking action of diode 38. However, a small reverse current does flow from the battery or batteries 41a-41n because of the stored charge on the intrinsic capacitance of the diode 38 and/or from the stored charge on the capacitor 42, if present to augment the intrinsic capacitance to repolarize the diode 38, after which no further discharge can take place. This small reverse current flow into terminal 35 coupled with the collapse of voltage across the tertiary winding induces a positive voltage at terminal 27 of the transformer secondary winding 26 which again initiates regeneration and the cycle is repeated. Depending upon the characteristics of transformer 21 and the diode 38, it may be desirable to increase the battery discharge current which reinitiates an oscillation cycle. Such is the purpose of the capacitor 42. When the voltage at the terminal 35 is no longer sufficient to force charging current into the positive terminal of battery 41a and the batteries 41a-41n start to discharge, current in addition to that required to repolarize the diode 38 will flow to repolarize the capacitor 42, if present. The amount of such additional current and the time period during which it flows is dependent upon values of the intrinsic capacitance of the diode 38 and the capacitance of the capacitor 42, if present, and the intrinsic resistance of the diode. The time period it takes for the stored charge to migrate across the junction of the diode 38 or recombine with majority carriers can be referred to as a delay.
If no batteries 41a-41n are in place, the circuit of the transformer 21 tertiary winding is open. No smoothing capacitor is connected in parallel with the batteries 41a-41n. No battery discharge current is present to reinitiate an oscillation cycle. The driven blocking oscillator consequently remains idle, except for an occasional sporadic single oscillation cycle initiated by transients.
The frequency of oscillation of the charger circuit is dependent upon the number of batteries to be charged. As the number of batteries in the charging stations is increased, the total voltage of the batteries under charge increases, reducing the time from the start of collapse of the transformer field until time that the voltage induced at terminal 35 can no longer force charging current into the batteries 41a-41n.
The charger circuit of the invention requires no adjustment or alteration to accommodate the various voltages normally encountered as input power sources. The charging current delivered to the battery or batteries under charge is dependent, to first order only, on the current threshold set by the sensing circuitry, which is constant and independent of the voltage of the input power source.
FIG. 2 illustrates a modification of the invention shown in FIG. 1 in which an SCR 45 is substituted for the sense transistor 30 (FIG. 1) and other modifications are made, as well. The SCR 45 transitions more rapidly from a non-conducting state to a conducting state than the transistor 30 (FIG. 1) acting alone, when triggered, thereby improving the efficiency of the circuit. The starting circuit, which operates upon the initial application of power, has also been modified as indicated hereinbelow.
The anode of SCR 45 is connected to the base of the transistor 23 and the cathode thereof is connected to the return line 16. The gate electrode of the SCR 45 is connected to the emitter of transistor 23 through a protective diode 46, its anode being connected to the emitter of the switching transistor 23. The cathode of a Zener diode 47 is connected to the terminal 27 of the secondary winding 26 of the transformer 21, the anode thereof being connected to the return line 16. The Zener diode 47 limits the voltage at the terminal 27 to prevent excessive current flow into the base of the transistor 23 which tends to inhibit the turn-off of this transistor. A resistor 48 limits the peak current in the diode 47, improving efficiency. The cathode of a second Zener diode 50 is connected to the terminal 22 of the primary winding 20, the anode thereof being connected to the return line 16 to prevent the application of excessive voltage by the transformer primary winding 20 to the transistor 23. The Zener diode 43 and the diode 44 may be used alternatively to protect the transistor 23, as in the embodiment illustrated in FIG. 1.
The starting circuit of the embodiment of FIG. 2 includes a resistor 51, inserted in series between the filter capacitor 17 and the return line 16. The resistor 48 is connected between the junction of the capacitor 17 with the resistor 51 and the terminal 25 of the transformer secondary winding 26. When power is initially applied to the circuit a positive voltage pulse will appear at the junction of the capacitor 17 and the resistor 51. This positive voltage is applied through the resistor 48 and the secondary winding 26 to the base of the transistor 23 and to the anode of the SCR 45, creating the first cycle of oscillation of the blocking oscillator. Further oscillation cycles, however, require the presence of a chargeable battery or batteries in the circuit of the transformer tertiary winding to provide feedback pulses, just as in the circuit of FIG. 1. The circuit of FIG. 2, when it is driven by a battery or batteries 41a-41n functions in the same fashion as the circuit of FIG. 1.
In FIG. 3, a further illustrative embodiment of the battery charger of the present invention incorporates a feature from the circuit of FIG. 2 as a modification to the circuit of FIG. 1. The circuit of FIG. 3 differs from the circuit of FIG. 1 in that the smoothing capacitor 17 is not directly connected to return line 16; rather, as in the circuit of FIG. 2, it is connected to the return line via a resistor 51, the connecting point between the resistor 51 and the capacitor 17 being connected to the collector of the transistor 30 and to the base of the transistor 23 via a series connection through the secondary winding 26 of the transformer 21. Thus, whenever the charger is initially connected to the source 10, a positive voltage spike appears on the collector of the transistor 30 and the base of the transistor 23 assuring the initial triggering of the circuit in a regenerative fashion. Thus, the circuit will operate over a wide range of line and battery voltages. More efficient power consumption is also achieved. The capacitor 34 also aids in initiating conduction of the transistor 23 during the initial cycle.
Although batteries of the nickel-cadmium type are generally tolerant to overcharging, certain types of batteries may be severely damaged by overcharging. FIG. 4 shows a modification in the charger circuits of FIGS. 1-3 which prevents overcharging the batteries under charge. The respective circuits of FIGS. 1-3 (not shown in FIG. 4) are unchanged up to the point of connectors 36 and 40. In FIG. 4, instead of being directly conductively connected in series between the connectors 36 and 40, each of the batteries 41a-41n under charge is respectively connected to respective pairs of output lines 52a-52n and 53a-53n of a similar number of identical modules 54a-54n.
Each of the modules 54a-54n comprises a respective input line 55a-55n and a respective return line 56a-56n. The anode of respective silicon controlled rectifiers (SCR's) (only two 57a, 57b being shown) is connected to a respective input line 55a-55n, the respective cathodes thereof being connected to respective return lines 56a-56n. The anodes of respective diodes (only two 58a, 58b being shown) are connected respectively to the respective input lines 55a-55n and the cathodes thereof are connected to respective output lines 52a-52n. Each of the diodes may be paralleled by a respective capacitor (only two 60a, 60b being shown) to serve the same purpose as the capacitor 42 of FIGS. 1-3. The return line 56a of the first module 54a is directly conductively connected to the input line 55b of the next module 54b via a lead 59a and so on for the succeeding modules 54b-54n via respective leads 59b and 59c. The return line 56n of the last module 54n is connected to the connector 40. Respective voltage dividers comprising respective series connected pairs of resistors (only resistor pairs 61a, 62a and 61b, 62b being shown) are connected across respective output lines 52a,53a-52n-53n. The voltage dividers sense the terminal voltage of the respective batteries 41a-41n connected across the respective output lines 52a,53a-52n,53n to the respective batteries 41a-41n. Respective amplifiers (only two 65a, 65b being shown) comprising respective interconnected pairs of transistors (only two pairs 63a, 64a and 63b, 64b being shown) are connected between respective output lines 52a-52n and respective return lines 53a-53n. The emitters of the respective transistor 63a, 63b and so forth are connected to respective output lines 52a-52n; the respective bases thereof are connected to the respective collectors of the respective transistors 64a, 64b and so forth. The respective collectors thereof are respectively connected to the respective gate electrodes of the respective SCR's (only two SCR's 57a and 57b being shown). The bases of the respective transistors 64a, 64b and so forth are connected to the respective junctions of the respective resistors 61a,62a; 61b, 62b and so forth, the respective emitters thereof being connected to the respective return lines 56a-56n.
The pairs of resistors 61a, 62a; 61b, 62b and so on are so proportioned that the bias applied thereby to the respective bases of the respective transistors 64a, 64b and so on will be inadequate to render these respective transistors conductive as long as the voltage of the associated battery 41a-41n is below a critical level. As long as any one of the transistors 64a, 64b and so forth is nonconductive, its associated transistor 63a, 63b and so on will likewise be nonconductive and the gate of the respective associated SCR's 57a, 57b and so on will not be forward biased; thus, the particular SCR will likewise, therefore, be nonconductive. Charging current under these conditions flows into the positive terminal of the respective batteries 41a-41n.
When any of the respective batteries 41a-41n become substantially fully charged (that is charged to the critical level as determined by the selected design), a respective one of transistors 64a, 64b and so on becomes conductive, rendering a respective one of the transistors 63a, 63b and so forth conductive, applying forward bias to the gate of a respective one of the SCR's 57a, 57b and so forth to cause the respective SCR to conduct. When any one of the SCR's 57a, 57b and so on conducts, charging current on one of the respective lines 55a-55n flows directly to one of the respective return lines 56a-56n and cannot enter the associated fully charged battery. Charging current continues to flow to the input line of the succeeding module in the chain and so on, until all of the batteries in the series become substantially fully charged. The respective diodes 58a, 58b and so forth prevents associated batteries 41a-41n from discharging through its associated SCR 57a, 57b and so on when the latter becomes conductive, although a small amount of discharge current will flow, as in the circuits of FIGS. 1-3, to repolarize the respective diode 58a, 58b and so on as the diode 38 of FIGS. 1-3, resulting in feedback to the driven blocking oscillator so long as any of the batteries 41a-41n requires more charge.
It is to be appreciated that the aforegoing description of preferred embodiments of the battery charger of the present invention, as well as various subcombinations thereof, have been set out by way of example not by way of limitation. Numerous other embodiments and variants are possible without departing from the spirit and scope of the present invention, its scope being defined in the appended claims.
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A battery charger of the driven blocking oscillator type includes a three-winding transformer. The primary winding is connected in series with the collector-emitter path of a switching transistor. The secondary winding is connected in series with the collector-emitter path of a sense transistor which responds to the current flowing through the switching transistor. The tertiary winding is connected in series with the battery, series-connected batteries or series-connected battery packs sought to be recharged, via a diode, which may be connected in parallel with a capacitor. No smoothing capacitor is provided across the battery or batteries. The battery or batteries are charged by current pulses and discharge through the tertiary winding to repolarize the diode (and capacitor if present). The secondary winding is poled, with respect to the tertiary winding so that the blocking oscillator is driven by energy from the battery or batteries. The battery charger can operate over a wide range of input voltages with high efficiency, making it useful worldwide. The charger is effective to charge batteries and series connections thereof over a wide range of battery voltages. The charger will only function if at least one rechargeable battery is in circuit for charging. The charger may include circuitry for automatically taking substantially charged batteries or battery out of the charge path.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application No. 60/927,325, filed May 3, 2007, and entitled “Output Shaft, Teeter Lever and Pinion Gear Arrangement for Pneumatic Differential Engine”, the entire disclosure of which is incorporated herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, generally, to a teeter lever for pneumatic cylinder/differential engine power-operated doors and, more particularly, to a removable teeter lever and removable gear for a pneumatic cylinder/differential engine for connecting an output shaft to connecting rods and, thence, to door panels of a mass transit vehicle.
2. Description of Related Art
Pneumatic cylinders have been utilized in mechanical systems to convert compressed air into linear reciprocating movement for opening and closing doors of passenger transportation vehicles. An example of this type of door actuating system is shown in U.S. Pat. No. 3,979,790.
Typically, pneumatic cylinders used in this environment consist of a cylindrical chamber, a piston and two end caps hermetically connected to the cylindrical chamber. The end caps have holes extending therethrough to allow the compressed air to flow into and out of the cylindrical chamber, to cause the piston to move in a linear direction, and to apply either an opening or closing force to the vehicle door.
Pneumatic cylinder/differential engine systems have also been designed for opening and closing doors of passenger transportation vehicles. Examples of these systems are shown in U.S. Pat. Nos. 4,231,192; 4,134,231; and 1,557,684.
As illustrated in FIG. 1 , a known pneumatic differential engine consists of a large pneumatic cylinder 1 and a small pneumatic cylinder 2 attached to a housing 3 . The large pneumatic cylinder 1 is closed at one end by a large cap 48 . The small pneumatic cylinder 2 is closed at one end by a small cap 50 . A large piston 4 and small piston 5 are installed inside of the cylinders 1 and 2 , respectively. Pistons 4 and 5 are attached to the toothed rack 6 which is engaged with the gear 7 . The gear 7 is permanently attached to the shaft 8 , so that linear movement of the pistons 4 and 5 is converted into rotational movement of the output shaft 8 . The teeter lever 9 , as shown in FIG. 2 , is welded to the end of the output shaft 8 , and is connected by the rods 10 , 11 and levers 12 , 13 to the vertical shafts and arms linked to the vehicle door panels (not shown). As a result, rotational movement of the output shaft 8 causes rotational movement of the teeter lever 9 which causes opening and closing of the vehicle doors.
The small pneumatic cylinder 2 is constantly connected to a reservoir of compressed air, through opening 52 in small cap 50 so that a positive pressure is constantly applied to the surface 54 of the small piston 5 facing small cap 50 . The large pneumatic cylinder 1 is connected to a three-way valve via opening 49 , which provides connections to a source of compressed air during a door closing mode or to an exhaust member for exhausting the air from the large cylinder 1 during a door opening mode. The spring system 14 and sealing disk 15 provide cushioning of the movement of the large piston 4 at the end of the door opening stroke.
During a door closing mode, the air is admitted to large cylinder 1 through the three-way valve, as discussed above, and pressure is applied to the surface 56 of large piston 4 facing the large cap 48 . Because of the difference in the surface area of large piston 4 and small piston 5 , the application of air pressure within the large cylinder 1 causes the pistons 4 and 5 to move toward small cap 50 or to the right (as shown). Linear movement of the rack 6 is converted into counter-clockwise rotation of the gear 7 and output shaft 8 and, consequently, rotation of the teeter lever 9 , which causes the doors to close.
During a door opening mode, the large cylinder 1 is connected to the exhaust valve of the three-way valve to allow the air in this large cylinder 1 to flow out due to pressure acting on the surface of the small piston 5 in small cylinder 2 . As a result of this pressure differential, pistons 4 and 5 move toward large cap 48 or to the left (as shown), rotating the gear 7 , shaft 8 , and teeter lever 9 in the clockwise direction, as viewed in FIG. 1 . The movement of the piston 4 toward the large cap 48 causes compression of the spring system 14 , and linear movement of the sealing disk 15 toward a cushioning chamber 58 .
Cushioning at the end of the door opening mode occurs as the disk 15 seals the exhaust opening 59 of cushioning chamber 58 . The air flow out of the cylinder is restricted to a small orifice (not shown), slowing the movement of the pistons 4 and 5 . This slowed movement allows the doors to continue opening at a slow speed (cushioning) until fully opened.
In the present engine design, the teeter lever 9 is welded to the output shaft 8 and the pinion gear 7 is secured to the output shaft by a roll pin inserted into a hole extending through the hub of the pinion gear and the shaft. This hole is drilled as a single operation with the pinion gear 7 already positioned on the welded shaft 8 and teeter lever 9 assembly. Once this hole is drilled, the pinion gear 7 and the welded shaft 8 and teeter lever 9 assembly become a matched set, inasmuch as the angular relationship of the teeter lever 9 to the pinion teeth determines the angular synchronization of the door panels to the position of the piston 4 , and rack 6 assembly within the differential engine.
In order to remove the teeter lever 9 from the engine, the engine must be disassembled and the roll pin driven out of the gear 7 and the shaft 8 and teeter lever 9 assembly. If either the pinion gear 7 or the teeter lever 9 and shaft 8 assembly is damaged, all of these components must be replaced in order to restore the differential engine to operation.
It can be observed from the design of the existing differential engine, that replacement of either the teeter lever 9 or the pinion gear 7 requires that the entire mechanism be disassembled. Neither the pinion gear 7 , nor the shaft 8 and teeter lever 9 , are interchangeable. Consequently, these components must be replaced as a set. Moreover, the pneumatic differential engine, once assembled, becomes unique to a specific door configuration, and differential engines cannot usually be interchanged between different door configurations.
These factors impose both labor and material expense burdens upon the maintenance of door systems equipped with the present pneumatic differential engine.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a removable teeter lever/gear assembly arrangement for pneumatic cylinder/differential engine power-operated vehicle doors. It is a further object of the invention to provide a teeter lever/gear assembly arrangement which can be easily removed and replaced without disassembling the differential engine. It is still another object of the invention to provide a teeter lever/gear assembly wherein replacement of individual parts is easy and cost effective.
The present invention comprises a removable teeter lever and gear assembly arrangement for use with pneumatic cylinder/differential engine power-operated vehicle doors. The arrangement comprises a teeter lever which is associated with the vehicle doors via rods and levers to the vertical shafts and arms linked to the vehicle door panels, such that rotation of the teeter lever causes opening and closing of the vehicle doors. A gear assembly having a toothed member and an output shaft extending therethrough are provided such that rotational movement of the gear assembly is caused by actuation of the pneumatic cylinder/differential engine. A securing member in the form of at least one retention key cooperating with at least one keyway formed in the output shaft is provided for removably securing and/or retaining the teeter lever onto the output shaft and for removably securing and/or retaining the gear onto the output shaft.
These and other features and characteristics of the present invention, as well as the method of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic section view of the pneumatic cylinder/differential engine of the prior art for controlling power operated doors of a vehicle;
FIG. 2 shows a perspective view of the teeter lever/gear assembly arrangement of the prior art mounted on a vehicle;
FIG. 3 shows a perspective view in partial section of the teeter lever/gear assembly arrangement in accordance with the present invention; and
FIG. 4 shows a perspective view of the teeter lever/gear assembly arrangement of FIG. 3 mounted on a vehicle.
DETAILED DESCRIPTION OF THE INVENTION
For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations, except where expressly specified to the contrary. It is also to be understood that the specific devices illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.
Reference is now made to FIG. 3 , which shows the removable teeter lever/gear assembly arrangement of the present invention, generally indicated as 100 , for use with a pneumatic cylinder/differential engine for opening and closing vehicle doors. As illustrated in FIG. 4 , the removable teeter lever 16 is connected by the rods 40 , 41 and levers 42 , 43 to the vertical shafts and arms linked to the vehicle door panels (not shown). Referring back to FIG. 3 , actuation of the pneumatic cylinder/differential engine during a door opening or closing operation causes a gear 17 to rotate with respect to a toothed rack 60 , which causes rotation of an output shaft 20 . This rotational movement of the output shaft 20 causes rotational movement of the teeter lever 16 which results in opening and closing of the vehicle doors.
As illustrated in detail in FIG. 3 , the gear 17 is removably connected with a first portion of the output shaft 20 through the use of a first retention key 18 a , which cooperates with a keyway 18 b in the output shaft 20 . The teeter lever 16 is removably connected with a second portion of the output shaft 20 through the use of a second retention key 19 a , which cooperates with a second keyway 19 b in the output shaft 20 . The first and second retention keys 18 a , 19 a can comprise any well-known key design capable of attaching rotating circular members with one another. One example of retention keys 18 a , 19 a , which can be used with the present invention are Woodruff keys, which are removable keys that fit in a matching keyway cut into a shaft, leaving a protruding tab. The tab mates with a matching slot on a device mounted flush upon the shaft; e.g., a pulley, thus preventing the device from freely rotating about the shaft. Typically, a Woodruff key is a semicircular shaped or half-moon key that fits in a semicircular shaped matching keyway.
The gear 17 and output shaft 20 are prevented from axially moving within the arrangement 100 by holding members such as retaining rings as discussed in detail below. The gear 17 is prevented from moving axially on the output shaft 20 by a first pair of retaining rings 21 a , 21 b positioned on either side of the output shaft 20 . The output shaft 20 is secured against axial motion relative to the gear housing 30 by a second pair of retaining rings 25 a , 25 b that bear against lubricant impregnated bushings 26 pressed into the sidewalls 28 of the gear housing 30 . Retaining rings 21 a , 21 b , 25 a and 25 b preferably comprise split ring retaining rings which are seated within slight indentations 36 in the output shaft 20 .
The teeter lever 16 is also secured against axial movement with respect to the output shaft 20 by a removable axial securing member, generally indicated as 22 . This axial securing member 22 can comprise any well-known securing member which may be readily removed from the arrangement 100 , such as a screw 23 and washer 24 . The screw 23 is threaded through a first aperture 32 in the teeter lever 16 , which is aligned with a second aperture 34 in the output shaft 20 .
The keyways 18 b , 19 b in the output shaft 20 and the pinion gear 17 are manufactured with a standard angular relationship to one another. The position of the keyway 19 b in the teeter lever 16 can be varied to adapt the final arrangement 100 to different door configurations.
Disassembly of the teeter lever 16 and gear assembly arrangement 100 occurs as follows. Removal of the teeter lever 16 from the arrangement 100 is achieved by simply removing screw 23 holding the teeter lever 16 to the output shaft 20 . This allows the teeter lever 16 to be easily slid off the output shaft 20 and retention key 19 a . The gear 17 may be removed from the arrangement without removing the teeter lever 16 . This is achieved by a multiple-step process. Screws 39 , which attach the cover portion 38 to the gear housing 30 , are loosened and removed so that the cover portion 38 is removed. The split ring retaining member 25 a , located adjacent housing 30 at the end opposite from the teeter lever 16 , is removed from the output shaft 20 . Then the “doors fully closed” target, not shown, is removed from the output shaft 20 . Retaining ring 21 a , adjacent gear 17 , retaining ring 21 b , and adjacent gear hub extension 42 , are removed from the output shaft 20 . The output shaft 20 , including retention key 18 a , can now be slid out from the interior portion of the gear 17 and the gear 17 can be lifted out of the gear housing 30 for repair and/or replacement thereof.
The present invention provides a differential engine wherein the teeter lever 16 and gear 17 can be easily removed and replaced. This significantly decreases the maintenance and/or labor required to correct a failure of the teeter lever 16 or of the pinion gear 17 .
Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of this description. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.
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A removable teeter lever and gear assembly arrangement ( 100 ) for use with a pneumatic cylinder/differential engine for operating vehicle doors. The arrangement comprises a teeter lever ( 16 ), which is associated with the vehicle doors, a gear assembly ( 17 ) having a toothed portion and an output shaft ( 20 ) extending therethrough, and at least one securing member for removably securing and/or retaining the teeter lever ( 16 ) and the gear ( 17 ) on the output shaft ( 20 ). The securing member comprises at least one retention key ( 18 a, 19 a ) which allows the arrangement to be easily disassembled for maintenance and/or replacement thereof.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to cutting elements for rotary drill bits for subterranean drilling, and more specifically to cutting elements providing a controlled superabrasive contact area during a predominant portion of the useful life of the cutting element, as well as bits so equipped and methods of drilling therewith.
2. State of the Art
Rotary bits are the predominant type of drill bits employed for subterranean drilling to oil, gas, geothermal and other formations. Of the types of rotary bits employed, so-called fixed cutter or “drag” bits have garnered an ever-increasing market share over the past few decades. This market share increase is attributable to a number of factors, but significant ones must be acknowledged as the wide availability and performance of superabrasive cutting elements.
Superabrasive cutting elements in their present state typically take the form of a polycrystalline diamond compact (PDC) layer or “table” formed onto a supporting substrate, typically of a cemented or sintered tungsten carbide (WC), in a press under ultra-high pressure and temperature conditions. Other superabrasive materials are known, including thermally stable PDCs, diamond films, and cubic boron nitride compacts. The present invention has utility with cutting elements employing any superabrasive material.
Several physical configurations of superabrasive tables for cutting elements are known, including square, “tombstone” shape, and triangular. However, the most common shape is circular, backed by a circular substrate of like size. These circular superabrasive tables are usually formed substantially to size in a press, but may be cut from larger, disc-shaped blanks. The other referenced shapes are generally required to be cut from a larger, disc-shaped blank, thus generating a large volume of scrap, reducing yield during fabrication and increasing fabrication costs.
As can be seen in FIGS. 1 and 2 of the drawings, state-of-the-art, disk-shaped cutting element 10 includes a circular, PDC superabrasive table 12 of substantially constant depth mounted to a disk-shaped WC substrate 14 . Superabrasive table 12 includes a cutting face 16 , a cutting edge 18 at the periphery of cutting face 16 , and a side 20 to the rear of cutting edge 18 (taken in the direction of cutting element travel, cutting face-first). Cutting element 10 would typically be oriented on a drill bit with at least a nominal negative backrake so that cutting face 16 “leans” away from the formation being drilled. As the cutting edge 18 and side 20 of superabrasive table 12 of cutting element 10 first contact the formation under application of weight on bit (WOB) at location 22 of cutting edge 18 , it can be seen that the superabrasive contact area is extremely small in both longitudinal depth or thickness as well as width, in part due to the aforementioned backrake. Thus, for a given WOB, the responsive loading per unit surface area at the side 20 of superabrasive table 12 contacting the formation being drilled is extremely high.
Due to the circular shape of the superabrasive table 12 , however, as the cutting element 10 begins to wear and a so-called “wear flat” forms at one side of cutting face 16 , superabrasive table 12 and the WC substrate 14 therebehind, the contact area of the superabrasive material under WOB, or so-called Normal force applied along the axis of the drill string to which the bit is secured, increases markedly in width and therefore in total area. The increasing contact area consequently requires an increase in WOB to maintain cutting element loading in terms of load per superabrasive unit surface area in contact with the formation to continue an acceptable rate of penetration (ROP). However, as WOB increases, so does wear on the superabrasive table, as well as the likelihood of spalling and fracture damage thereto. In addition, the requirement to increase WOB may undesirably affect drilling performance in terms of reducing steerability of a bit, as well as precipitate stalling of a downhole motor when the torque required to rotate under excessive WOB is exceeded, with consequential loss of tool face orientation. As can readily be visualized by looking at the relative contact area widths at location 22 , location 24 (as the cutting element is about 20% in diameter worn) and location 26 (as cutting element 10 is about 40% in diameter worn and typically approaching, if not well past, the end of its useful life), the superabrasive contact area may increase by more than an order of magnitude from the time a cutting element first engages a formation until the end of its useful life, thus requiring an attendant increase in WOB to maintain ROP in a given formation.
This undesirable increase in superabrasive contact area is present in conventional PDC cutting elements bearing constant-thickness superabrasive tables of about 0.030 inch thickness. However, as cutting elements bearing tables of greater thicknesses are developed, for example 0.070 inch and 0.100 inch uniform-thickness tables, the contact area increase is exacerbated. The increase in wear flat area for such PDC cutting elements of 13 mm (0.529 inch) diameter is illustrated in FIG. 9, wherein superabrasive contact area versus percentage of cutting face diametric wear is shown respectively by lines A, B and C for cutting elements of 0.030, 0.070 and 0.100 inch superabrasive table thickness. For each of the 0.030 inch, 0.070 inch and 0.100 inch thickness tables, the contact area more than doubles between 5% and 30% diametric wear of the superabrasive table. More significantly, for the 0.070 inch and 0.100 inch thickness superabrasive tables, contact area quickly increases in absolute terms to in excess of 0.02 square inch (the maximum superabrasive contact area for a 13 mm, 0.030 inch thick table PDC cutting element), thus necessitating substantial and undesirable WOB increases extremely early in the life of the cutting element in order to maintain the load per unit surface area of superabrasive material contacting the formation. While use of a square or tombstone-shaped cutting face, would obviously provide a relatively constant superabrasive contact area, as noted above such configurations are undesirable for other reasons. Consequently, there is a need in the art for a cutting element exhibiting a circular cutting face and superabrasive table, the term “circular” as used herein including a segment of a circle a segment or which otherwise exhibits an arcuate or nonlinear cutting edge, which provides a relatively constant superabrasive contact area during a large portion of the useful life of the cutting element.
BRIEF SUMMARY OF THE INVENTION
In contrast to the circular or disk-shaped cutting elements comprising the state of the art, the cutting elements of the invention are configured with superabrasive tables having configurations such that the surface area of superabrasive material in contact with a formation being cut by the cutting element responsive to WOB quickly reaches a relatively stable value, which value remains relatively constant over a substantial portion of the useful life of the cutting element, for example, from about 5% to about 30% wear across the diameter of the cutting face. The present invention provides this relatively stable value of a relatively small magnitude, for example, from about 0.018 to about 0.021 square inch for a 13 mm (0.529 inch) diameter cutting element.
One embodiment of the cutting element of the present invention is configured with a planar cutting face and a non-planar interface between the superabrasive table and the supporting substrate, wherein at least one radially-oriented, substantially isosceles triangular projection of increased superabrasive table thickness lies adjacent the periphery of the superabrasive table with the triangle base oriented toward the formation. The superabrasive projection gradually decreases in thickness and width from a location adjacent the cutting edge at the periphery of the as-formed, unworn superabrasive table toward the center of the cutting element. During drilling, the decrease in thickness and width of the superabrasive projection as the cutting element wears is substantially offset by an increase in width of contact with the formation of the superabrasive table as a whole, attributable to the increasing lateral contact span of the thinner portions of the table laterally flanking the projection as the cutting element wears during use. In actual practice, it may be desirable to fabricate such a cutting element with, for example, four such triangular projections at 90° rotational intervals, so as to maintain symmetrical stress patterns at the superabrasive table-to-substrate interface. Such an embodiment may employ projections which immediately commence a decrease in depth from the cutting face periphery, or may maintain an initial constant depth or even increase in depth for a measurable distance from the table periphery, to provide a robust superabrasive mass to effect and sustain the initial contact with the formation until the wear flat is well-established.
Another embodiment of the invention features a cutting element employing a superabrasive table which features a thicker portion of constant width lying along a radius of the cutting element, the table decreasing non-linearly in thickness toward the center of the cutting element in proportion to the increase in contact area width of the superabrasive table, so as to maintain a substantially constant superabrasive contact area for a significant portion of the cutting element life.
It is contemplated that cutting elements according to the invention having superabrasive tables employing superabrasive projections or thickness increases leading or projecting from the cutting faces of the tables may be employed. For example, a triangular or other shape projection may lie on the cutting face, or the cutting face may be of a convex configuration, with the increased superabrasive depth exhibited as a domed, diametrically-extending ridge.
It is further contemplated that cutting elements according to the present invention may be configured with cutting tables of varying depth, wherein the depth variances are manifested both internally (at the substrate interface) and externally (as a projection from the cutting face, or non-planar cutting face), or both.
It is also contemplated that the invention may be embodied in the form of a half-circular, one-third circular, or other circular fraction cutting element having an internal or external superabrasive table projection, or both, of appropriately varying depth and/or width, as the case may be, extending from an arcuate cutting edge at a periphery of the table toward a center point from which the radius defining the cutting edge extends. The invention may also be employed with cutting elements exhibiting cutting edges of other than constant radius, such as ellipsoidal cutting edges, to compensate for increases in superabrasive contact area.
Finally, it may be recognized that extreme variations in backrake of a cutting element when mounted to a drill bit may necessitate some adjustment in the configuration in terms of variations in thickness and width of the deeper portions of the superabrasive table to ensure a substantially constant superabrasive contact area responsive to WOB, since a highly backraked cutting element will present a larger contact area to the formation than a slightly backraked one and the contact areas of cutting elements bearing particularly thick superabrasive tables will be particularly affected by large backrakes.
The invention also includes methods of drilling with bits equipped with cutting elements of the invention, wherein a relatively constant superabrasive contact area with the formation is maintained, and a substantially constant ROP may be maintained throughout a substantial portion of cutting element life under a relatively constant applied WOB.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIGS. 1 and 2 comprise, respectively, side and frontal views of a prior art, circular, superabrasive cutting element;
FIGS. 3A, 3 B and 3 C comprise, respectively, perspective, frontal and side sectional views of a substrate for a first embodiment of the invention;
FIG. 4 comprises a perspective view of a cutting element of the first embodiment of the invention;
FIGS. 5A, 5 B and 5 C comprise, respectively, side, frontal and perspective views of one variant of the first embodiment, FIG. 5D is an enlarged side view of the cutting edge area of the superabrasive table, and FIG. 5E is a perspective view of the leading face of a substrate for that variant;
FIGS. 6A, 6 B and 6 C comprise, respectively, perspective, frontal and side sectional views of a substrate for another variant of the first embodiment;
FIGS. 7A and 7B comprise, respectively, frontal and side sectional views of a second embodiment of the invention;
FIGS. 8A and 8B comprise, respectively, frontal and side views of a third embodiment of the invention;
FIG. 9 comprises a graph of superabrasive wear flat area as a function of percent of circular superabrasive table diametrical wear;
FIGS. 10A, 10 B and 10 C depict, respectively, additional cutting element embodiments of the invention exhibiting arcuate cutting edges and other than circular cutting faces; and
FIG. 11 depicts a rotary drag bit having cutting elements according to the invention mounted thereto.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 3A-3C and 4 , a first embodiment 100 of the cutting element of the present invention will be described. Cutting element 100 includes substrate 102 in the shape of a preformed, longitudinally truncated cylinder fabricated of sintered or cemented WC or other suitable material, as known in the art. The trailing face 104 of substrate 102 as shown is flat, while the leading face 106 carrying superabrasive table 130 (see FIG. 4) is non-planar, comprising a plurality of substantially triangular indentations 108 at 90° intervals, the indentations 108 being separated by ridges 110 which converge at the center 124 of the substrate 102 , the top surfaces 111 of the ridges 110 lying substantially on the same plane transverse to the longitudinal axis L of cutting element 100 so as to exhibit a “cross” shape to the viewer. The substantially triangular indentations 108 may be characterized as isosceles in general character, and are each bounded by two linear sides 112 defining about a 60° angle α therebetween, a short inner arcuate boundary 114 connecting converging linear sides 112 , and an outer arcuate edge or base 116 extending between sides 112 and coincident with the outer periphery or side 122 of the substrate 102 in a finished cutting element 100 . The transitions, as at 120 , from the floors 118 of the indentations 108 to sides 112 and boundary 114 and from sides 112 and boundary 114 to ridge top surfaces 111 are preferably radiused rather than sharply angled, for example, along about a 0.02 inch radius. As shown, indentation floors 118 are relatively flat, angled or tilted along a radius of substrate 102 at about a 10° angle of inclination β to ridge top surfaces 111 of the ridges 110 , and located so that a line extending from each floor 118 toward center 124 would intersect a line parallel to the ridge top surfaces 111 and about 0.010 inch therebelow (i.e., within substrate 102 ) at about a 0.060 inch radial distance from center 124 , so as to provide a decrease in thickness of the indentations 108 as they extend from the side 122 of the substrate 102 toward the center 124 thereof.
As can be seen in FIG. 4, superabrasive table 130 , preferably comprised of a PDC, is formed on leading face 106 of substrate 102 as known in the art. Table 130 exhibits a substantially planar imperforate cutting face 132 , and superabrasive projections 134 fill indentations 108 of substrate 102 . The depth of superabrasive table 130 at projections 134 may be, for example, about 0.080 inch at the cutting edge 136 . The remainder of table 130 , other than projections 134 and substantially comprising the table area lying over the “cross” of ridges 110 , and center 124 of substrate 102 , comprises portions of lesser and substantially constant superabrasive thickness, for example, about 0.040 inch. Further, the surface of cutting face 132 preferably exhibits a high degree of smoothness, as disclosed and claimed in U.S. Pat. Nos. 5,447,208 and 5,653,300 to Lund et al., assigned to the assignee of the present invention. It is preferred that at least a portion of the cutting face surfaces of all of the embodiments of the invention exhibit a high degree of smoothness as taught by the Lund et al. patents.
In use, cutting element 100 is preferably placed with one of the substrate indentations 108 and its associated superabrasive material projection 134 oriented away from the face of the bit on which cutting element 100 is mounted, and toward the formation to be cut by cutting element 100 in a shearing-type cutting action. Such an orientation ensures, after an initial rapid increase in superabrasive contact area as an initial contact point at cutting edge 136 of table 130 wears laterally into a flat during the first 5% or less of diametric cutting face wear, that further lateral increases in the wear flat will be substantially offset by decreases in depth and width of the projection 134 until the cutting face is diametrically worn in excess of about 30%. Thus, as shown by line D in FIG. 9, the superabrasive contact area for the cutting element embodiment 100 in question will, for a 13 mm diameter cutting element, only increase from about 0.018 square inch to about 0.021 square inch as cutting element 100 wears through the aforementioned range, and to only about 0.028 square inch by the time the cutting face is 40% diametrically worn, a point well past its typical useful life.
Referring now to FIGS. 5A-5E, a first variant cutting element 200 of the first embodiment is depicted. Cutting element 200 includes a substrate 202 having indentations 208 lying between radially-extending ridges 210 disposed at 90° circumferential intervals, as with cutting element 100 . However, unlike cutting element 100 , ridges 210 are defined by sloping side surfaces 212 (see FIGS. 5 A and 5 D), which extend downward on each side of a ridge 210 from ridge top 214 to meet floors 218 of laterally adjacent indentations 208 . In this variant 200 , the indentation floors 218 lie substantially parallel to the plane of the cutting face 232 and transverse to the longitudinal axis of cutting element 200 , rather than sloping as in cutting element 100 . Further, unlike in cutting element 100 , the sides of the ridges 210 are substantially parallel and the ridges 210 remain of substantially constant transverse cross section until meeting adjacent ridges 210 toward the center 224 of substrate 202 , rather than the ridges necking down as they approach the center. The thickness T 1 of superabrasive table 230 at projections 234 of superabrasive table 230 lying over the indentation floors 218 is about 0.080 inch, while the table thickness T 2 over the tops 214 of the ridges 210 is about 0.040 inch. In variant 200 , the superabrasive contact area is maintained relatively constant during wear of the cutting element by appropriate selection of the relative thicknesses of the table portions over the floors 218 and ridge tops 214 , the degree to which indentations 208 decrease in width as cutting element 200 wears, and the angles of the side slopes of the ridge side surfaces 212 extending between ridge tops 214 and indentation floors 218 .
Further, in cutting element 200 , the cutting edge 236 is chamfered to about a 0.015 inch radial width at a 45° angle to the cutting face 232 , and (as shown in FIG. 5A) at least part of the side of the table 230 may be angled at about a 10° angle γ to the side 222 of the substrate 202 as taught by U.S. Pat. No. 5,437,343 to Cooley et al, assigned to the assignee of the present invention. Alternatively, as shown in FIG. 5C, a chamfer and an angled table side may be eliminated, as desired.
FIGS. 6A through 6C depict a substrate 302 for another variant 300 of the first embodiment of the cutting element of the invention. Substrate 302 is similar to substrate 102 , except that leading face 306 includes substantially isosceles triangular indentations 308 having composite topography floors 318 , each comprising an outer, arcuate, flat shelf 317 oriented substantially parallel to the ridge top surfaces 311 of ridges 310 , shelf 317 extending radially inwardly a measurable distance D 3 (for example, about 0.030 inch) to an inner, substantially flat surface 319 . Surface 319 may actually be characterized as a very shallow, barely perceptible concavity comprising a section of a cone of revolution. Surface 319 is inclined along a radius of substrate 302 at an angle β, for example, about 10° for a 0.529 inch or 13 mm diameter cutting element, to the ridge top surfaces 311 of ridges 310 and located to intersect a line parallel to and 0 . 010 inch below ridge tops 311 about 0.060 inch radially outward of center 324 , so as to reduce the depth of the indentation 308 as the radial distance from the center 324 of the substrate 302 decreases. Composite topography floors 318 are bounded by a pair of linear, convergently-oriented sides 312 of adjacent ridges 310 (again defining about a 60° included angle) connected at their radially inner ends by arcuate boundary 314 and at their radially outer ends by outer arcuate base or edge 316 extending therebetween and substantially coincident with the outer periphery or side 322 of substrate 302 in a finished cutting element 300 . The boundary 321 between shelf 317 and inner, flat surface 319 is preferably arcuate or radiused, rather than sharp, for example, on about a 0.125 inch radius. The exterior of a cutting element formed with substrate 302 would look substantially identical to cutting element 100 (see FIG. 4 ), and so is not separately illustrated, although reference numerals applicable to cutting element 300 are shown in FIG. 4 for clarity. The transitions as at 320 between the outer periphery of shelf 317 and surface 319 and sides 312 and boundary 314 and between sides 312 and boundary 314 and ridge tops 311 are radiused, as with substrate 302 . The presence of shelf 317 at the outer periphery of each indentation 308 provides a larger depth of superabrasive material (see FIG. 4) in projections 334 of superabrasive table 330 at the cutting edge 336 to sustain initial impacts with the formation until a wear flat is formed, and thus may form a more robust cutting element. It is also contemplated (see FIG. 6C) that shelf 317 may even dip downward as it extends radially inward from the side 322 of substrate 302 , as shown in broken lines 317 ′, to provide an even greater effective thickness of superabrasive table 330 in a projection 334 oriented toward the formation and aligned with the resultant force acting on the cutting edge of the imperforate cutting face 332 and, further, that the angle of inclination β of surface 319 may be greater than 10° (again, as shown in broken lines 319 ′) to accommodate this configuration of shelf 317 .
FIGS. 7A and 7B depict a second embodiment 500 of the cutting element of the present invention. Cutting element 500 includes a substrate 502 onto which is formed a superabrasive table 530 . Table 530 includes at least one radial or diametric projection 534 of substantially constant widths and of increased thickness with respect to the remainder of table 530 . Projection 534 is thickest adjacent cutting edge 536 , and decreases in thickness non-linearly (such as along a radius of curvature R) as it approaches the center 524 of substrate 502 . Thus, as cutting face 532 and table 530 wears toward center 524 during use, the decreasing thickness of projection 534 is offset by the increase in superabrasive contact area with the formation afforded by the increasing width of the thinner table areas 533 flanking projection 534 .
FIGS. 8A and 8B depict a third embodiment 600 of the cutting element of the present invention. Cutting element 600 includes a substrate 602 onto which a superabrasive table 630 is formed, there being a substantially planar interface or boundary between the two elements. Table 630 includes a radial projection 634 protruding from the cutting face 632 , projection 634 decreasing in both depth and width toward the center 624 of substrate 602 so that the superabrasive contact area with the formation remains substantially constant as cutting edge 636 wears into a flat during drilling and the increase in the lateral width of the wear flat is offset by the decrease in the footprint size of the projection 634 . Optionally, as shown in broken lines 640 , projection 634 may extend from the rear of table 630 as well as, or in lieu of, from cutting face 632 .
FIGS. 10A, 10 B and 10 C respectively depict cutting elements exhibiting arcuate cutting edges and other than circular superabrasive tables and cutting faces. Cutting element 700 of FIG. 10A is of half-cylindrical configuration, with half-circular superabrasive table 730 , projection 734 extending to the rear thereof into the supporting substrate. Cutting element 800 of FIG. 10B is of one-third cylindrical configuration, with one-third circular superabrasive table 830 , projection 834 extending to the rear thereof into the supporting substrate. Cutting element 900 of FIG. 10C is of ellipsoidal configuration, with ellipsoidal superabrasive table 930 , projection 934 extending to the rear thereof into the supporting substrate.
FIG. 11 depicts a drill bit in the form of a rotary drag bit 1000 having cutting elements 100 , 200 and 300 mounted thereon in accordance with the present invention.
As noted previously, the cutting elements of the present invention may employ any known superabrasives, including without limitation, PDCs, thermally stable PDCs, diamond films, and cubic boron nitride compacts. It is contemplated that superabrasive tables according to the invention may be formed as free-standing superabrasive masses and employed as cutting elements secured directly to the bit face as by brazing or during infiltration of a matrix-type bit, in addition to being formed onto supporting substrates as is conventional in PDC fabrication. Substrates may take the form of cylinders or studs, as desired, the manner of securement of the cutting elements to the bit face being of no consequence to the invention.
It will be appreciated by those of ordinary skill in the art that the cutting elements of the invention permit maintenance of WOB for a given ROP (or range of ROPs) within a controlled, non-disadvantageous magnitude through control of the superabrasive contact area of the cutting elements on the bit with a formation being drilled. Thus, the present invention includes novel and unobvious methods of drilling.
While the cutting elements and drill bits of the present invention have been described in terms of certain illustrated embodiments, those of ordinary skill in the art will understand and appreciate that it is not so limited. Rather, additions, deletions and modifications to the illustrated embodiments may be effected, as well as combinations of features of different embodiments, without departing from the scope of the invention as set forth hereinafter in the claims.
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Cutting elements providing a relatively constant superabrasive area in contact with the formation responsive to weight on bit during a substantial portion of the useful life of a circular cutting face cutting element or other cutting element exhibiting a non-linear cutting edge, for example, from about 5% diametrical wear to in excess of about 30% diametrical wear in the case of a circular cutting element, measured across the cutting face. The superabrasive table of the cutting element is configured, internally, externally, or both, to vary in depth radially and laterally, as required, so that an increase in width of the contact or wear flat area with the formation and the variation in table depth as the cutting element wears, are substantially offsetting. The rate of penetration of a drill bit so equipped may thus be maintained at a desirable magnitude without a substantial increase in weight on bit as the cutting element wears, since the superabrasive contact area is maintained relatively constant.
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BACKGROUND OF THE INVENTION
The present invention relates to a straight combing machine for combing a sliver of fibres, particularly woollen fibers, comprising a support structure, a circular comb rotatably mounted on the structure, means for supplying the fibres to the circular comb and means for removing the combed fibres from the circular comb.
In conventional combing machines in which the means for removing the combed fibres comprise, as is known, a pair of detaching rollers and a leather sleeve which is interposed between the detaching rollers to improve the grip and serves as a conveyor plane for the tufts, the slivers of fibres normally supplied include fibres having an average length of more than 45-50 mm. These fibres, which have been washed and subsequently carded, are subjected to conventional combed spinning after the combing process.
With so-called "short" wools, that is with fibres having an average length of less than 40-45 mm, a problem arises with conventional straight combing machines in that too many fibres are discarded (noil) which means that the combing of short wools is not economically worthwhile.
SUMMARY
The object of the present invention is to provide a combing machine and a combing method which overcome the aforesaid problem.
According to the invention, this object is achieved by virtue of the fact that the means for removing the fibres from the circular comb comprise pincers for gripping the fibres and detaching them from the circular comb.
The use of pincers for gripping the ends of the tufts enables closer approach to the fixed comb and thus enables shorter tufts to be combed.
Suction means are preferably associated with the pincers for transporting the combed fibres to fibre-collection means when the pincers open.
As well as ensuring that the end of the tuft is arranged correctly to be gripped by the pincers, the suction means thus also remove the fibre flocks pneumatically to a storage device.
In current combing machines, in order to improve the penetration of the fibre tufts between the teeth of the comb, so-called mechanical "embedding" devices are used for urging the fibres towards the teeth of the comb to increase the combing efficiency.
As well as being quite complex structurally, these mechanical devices limit the number of beats per minute effected by the combing machine, thus restricting any increase in the productivity of the machine. Conventional embedders also require accurate regulation in relation to the timing of the circular comb.
In order to overcome this further problem, the combing machine of the present invention, which is of the type in which the circular comb is in the form of a hollow cylinder, also has a substantially longitudinal elongate aperture in the side wall of the comb, the interior of the circular comb being in communication with a vacuum source so as to encourage the penetration of the fibres of the silver between the teeth of the comb by suction.
By virtue of this further characteristic, it is no longer necessary to use so-called mechanical "embedding" devices which, because of the complexity of their structure, drive and setting up, limit the productivity of the machine.
With the use of suction towards the interior of the circular comb to embed the fibres in the teeth of the comb, it is possible to increase the operating rate (cycles per minute) of the machine without mechanical problems.
BRIEF DESCRIPTION OF THE DRAWING
Further characteristics and advantages of the combing machine and of the method of the invention will become clear from the detailed description which follows with reference to the appended drawings, provided by way of non-limiting example, in which:
FIG. 1 is a perspective view of a combing machine according to the invention,
FIG. 2 is a section taken on the line II--II of FIG. 1,
FIG. 3 is a view similar to FIG. 2 showing a different stage in the working cycle of the machine,
FIG. 4 is a view similar to FIGS. 2 and 3 and shows a further stage in the working cycle of the machine,
FIG. 5 is a view of a detail of FIG. 2 on an enlarged scale,
FIG. 6 is a detail of FIG. 4 on an enlarged scale,
FIG. 7 is a perspective view of part of the machine of FIG. 1 on an enlarged scale,
FIG. 8 is an exploded perspective view of a component of the machine, and
FIG. 9 is a view of a detail of FIG. 8 on an enlarged scale.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the drawings, a wool-combing machine is generally indicated 10 and includes a support structure 11, a feed unit 12 and a detaching unit 13. Slivers of wool-fibres, combined closely together so as to form a compact web M of even thickness, are fed to the machine 10 in known manner. The web is entrained by feed rollers 14 and is conveyed to the feed unit 12 which comprises an array of oscillating needles 15 which advance the web M intermittently.
A lower nipper 16 and an upper nipper 17 are pivoted to the structure 11 of the machine and arranged to hold a tuft C of fibres while it is being combed by a circular comb 18. The lower nipper 16 and the upper nipper 17 have respective ends 16a and 17a for gripping an end portion M 1 of the web M so as to define the tuft C which projects from the clamped nippers. A straight comb 19 is also arranged in the feed zone of the machine and is fixed at 2 to an oscillating structure 21 pivoted at 22 to the support structure of the machine. The straight comb 19 is used in known manner to comb the rear end of the tuft C. The straight comb 19 is cleaned by a brush 23 carried by the upper nipper 17.
The machine described hitherto does not differ substantially form conventional combing machines. The innovative characteristics of the machine according to the invention relate primarily to the zone in which the tufts of fibres are detached.
With particular reference to FIGS. 1 and 2, an oscillating assembly 25 is pivoted to the support structure 11 of the machine about a horizontal axis X--X and comprises two parallel arms 26, each pivoted at a first end 26a to a shaft 27 and having its second end 26b fixed to a cross-member 28 which interconnects the arms 26 and is parallel to the articulation axis X--X. The oscillation of the assembly 25 about the axis X--X is driven in synchronism with the machine by means of a pair of connecting rods 29, as will become clear from the description of the operation of the machine.
A suction manifold 30 is connected to the cross-member 28 of the oscillating assembly 25 and is connected at 30a, by means of a connecting tube 49, to the inlet of a suction fan 31. The manifold 30 has a lower edge portion 30b defining a first jaw of a pincer device. The manifold 30 also has a wall 30c which faces the supply unit 12 and has a curved shape in order to prevent interference with the movement of other members of the machine.
A lower jaw 32 is pivoted to the manifold 30 about a horizontal axis Y--Y parallel to the articulation axis X--X of the oscillating assembly and has an active portion 32b facing the portion 30b of the manifold 30. The second jaw 32 is moved by means of a pair of connecting rods 33 each pivoted at a first end to the jaw 32 (about a horizontal axis parallel to the axis Y--Y) and at a second end to one of a pair of levers 34 keyed to the shaft 27 which is mounted for rotation relative to the support structure 11. The shaft 27 is reciprocated about its axis by a further lever 35 keyed to one end 27a of the shaft 27 with the aid of a connecting rod 37 which is driven in synchronism with the machine. Each connecting rod 33 is also provided with a compression spring 33a arranged during the design stage to achieve a predetermined clamping force between the jaws 30b and 32b.
The manifold 30 has an internal duct 40 which communicates with a straight slot 41 adjacent the first jaw 30b. The duct 40 communicates through the connector 30a with delivery tubing 43 connected to a store (not shown), the fan 31 being arranged in this tubing.
According to another characteristic of the invention the circular comb 18, which has two segments 18a and 18b respectively provided with needles, has an internal tubular support body 50 whose interior is connected through a connector 51 to tubing 60 leading to a vacuum source constituted, for example, by a blower fan 61.
A space 52 is defined between the tubular body 50 and the circular segments 18a and 18b and communicates with the connector 51 through a straight slot 53 formed in the wall of the tubular body 50. Similarly, a straight slot 56 is provided in a recessed portion 57 of the second segment 18b of the circular comb which is the segment which has the denser distribution of needles 55. This recessed portion 57 is located between rows of teeth 55 substantially adjacent a curved connecting element 59 of the circular comb 18.
When the machine 10 is operating, at the stage shown in FIG. 2 the tuft C is combed by the circular comb 18 which, by virtue of the low pressure created in correspondence with the straight slot 56 and of the connection of the tubular body 50 to the vacuum source 61, draws the tuft C towards its lateral surface where the teeth of the comb are closer together. This "centripetal" suction ensures that the fibres constituting the tuft are drawn down fully between the teeth 55 of the circular comb 18. The suction starts before the circular comb 18 has reached the position in which its slot 56 is located in correspondence with the tuft C and stops when the latter has been combed.
The "timing" of the suction through the slot 56 is regulated, for example, by means of a distributor disc with suitable apertures placed in correspondence with the connector 51.
During the next stage, shown in FIG. 3, the upper nipper 17 moves away from the lower nipper 16 and simultaneously cleans the straight comb 19 by means of the brush 23. At the same time, the jaws 30b and 32b, which are in the open configuration, close on the tuft C so as to grip it between them and initiate the subsequent detachment stage shown in FIG. 4.
During this last stage, the straight comb 19 combs the rear end of the tuft C whilst, by virtue of the oscillation of the assembly 25, the tuft is separated from the web M which is retained by the array of needles 15. At the end of the detachment stage, the opening of the second jaw 32b away from the first jaw 30b formed by the manifold 30 causes the tuft to be drawing into the duct 40 and into the delivery tubing 43 towards the flock store.
To advantage, the suction in the manifold 30 is maintained throughout the operating cycles of the machine so as to facilitate the gripping of the tuft C which, as a result of the suction, aligns itself between the lower nipper 16 and the gripping line of the jaws 30b and 32b when the manifold 30 moves toward the nippers 16 and 17.
With the machine described above, the gauge can be reduced considerably in comparison with conventional combing machines, enabling it to be reduced to less than 15-16 mm. This is made possible both by the use of pincers for the detachment instead of conventional detaching rollers and by virtue of the particular shape of the jaws associated with the oscillating assembly 25. In parallel with the reduction in the gauge, particularly short wools can be combed effectively with low percentages of waste.
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A straight wool-combing machine (10) has, instead of the conventional pair of detaching rollers, a pair of jaws (30, 32) for gripping the combed end of a tuft and for separating it, by a withdrawal movement, from the rest of the fibre sliver (M). The pair of jaws (30, 32) has a suction fan (31) for transporting the combed fibres pneumatically to a collecting store.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to a freezer component which stores frozen food and automatically removes the frozen food from the freezer component in response to a signal
[0002] Freezers are used to keep objects, such as food, frozen. Freezers are commonly used in residences, grocery stores, and restaurants to keep food frozen. In the restaurant or food service industry, food is often stored in a freezer prior to preparation and serving. The food is usually manually placed into the freezer by an employee for storage. When the food is to be prepared and served, the food is manually removed by an employee and prepare for serving.
[0003] A drawback to the prior art freezers is that additional labor is needed to remove the food from the freezer prior to preparation for serving as the food is manually removed by an employee. It would be beneficial to use a freezer that automatically transfers frozen food from a freezer component to a preparation area in response to an operator request.
SUMMARY OF THE INVENTION
[0004] The freezer component of the present invention automatically removes frozen food from the freezer component in response to a signal. The freezer component includes a rotatable portion, a loading side and a feeding side. The rotatable portion is rotatable by a carousel. Two raiseable platforms are located in each of the loading side and the feeding side. Food is loaded into the freezer component by placing the food onto the platforms positioned in the loading side. The carousel then rotates the rotatable portion 180° to position the food-loaded platforms in the feeding side. Rods around the platforms prevent the food from falling from the platforms during rotation. The empty platforms now located in the loading side are loaded with additional food.
[0005] When a signal is received, food in the feeding side is automatically removed from the freezer component by alternately raising the two platforms holding the food. When a sensor detects that the feeding side is empty and contains no more food, the rotatable portion rotates 180° in the reverse direction, positioning the recently food-loaded platforms in the feeding side and the empty platforms in the loading side. Stops in the freezer component prevent over-rotation of the carousel.
[0006] These and other features of the present invention will be best understood from the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The various features and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:
[0008] [0008]FIG. 1 schematically illustrates a side view of the freezer component of the present invention;
[0009] [0009]FIG. 2 schematically illustrates a cross sectional view of the freezer component of the automated grill of FIG. 1 taken along line 2 - 2 ;
[0010] [0010]FIG. 3 schematically illustrates a top view of the carousel of the freezer component;
[0011] [0011]FIG. 4 schematically illustrates a cross sectional view of the freezer component of the automated grill of FIG. 1 taken along line 4 - 4 ; and
[0012] [0012]FIG. 5 schematically illustrates a perspective view of the exterior of the freezer component of the automated grill.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] [0013]FIG. 1 illustrates the freezer component 22 of the present invention. Frozen food items 52 , such as frozen hamburger patties, are loaded in the freezer component 22 . The freezer component 22 includes a rotatable portion 28 mounted on a carousel 30 . The freezer component 22 further includes a loading side 32 and a feeding side 34 . An upper sensor 42 and a lower sensor 44 are located proximate to the upper end and the lower end, respectively, of the rotatable portion 28 .
[0014] In one example, the freezer component 22 uses forced air convection. In another example, the freezer component comprises 22 a cold wall freezer. Preferably, the temperature in the freezer component 22 is between −18° C. and −21° C.
[0015] As shown in FIG. 2, the example rotatable portion 28 includes four surfaces 36 a , 36 b , 36 c and 36 d . When the rotatable portion 28 is positioned as in FIG. 1, the surfaces 36 a and 36 b are located in the feeding side 34 , and the surfaces 36 c and 36 d are located in the loading side 32 . A platform 38 a , 38 b , 38 c and 38 d is received against each of the respective surfaces 36 a , 36 b , 36 c and 36 d and is moveable in the Y direction (i.e., up or down according to FIG. 1) by a drive 40 a , 40 b , 40 c , and 40 d , respectively, shown in phantom, which is powered by a respective motor 45 a , 45 b , 45 c and 45 d (shown in FIG. 1). Preferably, the platforms 38 a , 38 b , 38 c and 38 d are circular.
[0016] When the platforms 38 c and 38 d in the loading side 32 (as in FIG. 1) are in a loading position, the platforms 38 c and 38 d are loaded with the food items 52 . Rods 41 located on the outer periphery of the platforms 38 a , 38 b , 38 c and 38 d create a cage to prevent the food items 52 from falling from the platforms 38 a , 38 b , 38 c and 38 d during rotation of the rotatable portion 28 . After a desired number of food items 52 are loaded, the carousel 30 rotates the rotatable portion 28 180° in a first direction, positioning the platforms 38 c and 38 d with the loaded food items 52 in the feeding side 34 . The same motion moves the platforms 38 a and 38 b to the loading side 32 . The platforms 38 a and 38 b can then be loaded with more food items 52 .
[0017] As shown in FIG. 3, the carousel 30 includes a magnet 19 . Opposing sensors 17 a and 17 b , such as magnetic reed sensors, are positioned proximate to the carousel 30 . When the carousel 30 rotates 180° and the sensor 17 a detects the magnet 19 , a signal is sent to the motor 43 by the control 51 to stop rotation of the carousel 30 . When the carousel 30 is rotated 180° in the opposing direction and the sensor 17 b detects the magnet 19 , a signal is sent to the motor 43 by the control 51 to stop rotation of the carousel.
[0018] The carousel 30 further includes a projection 46 to prevent over-rotation. Stops 47 and 48 located in the freezer compartment 22 prevent over-rotation of the carousel 30 and tangling of wires (not illustrated). If the carousel 30 over-rotates, the projection 46 engages one of the stops 47 and 48 , preventing further rotation of the carousel 30 .
[0019] Returning to FIG. 1, when at least one of the food items 52 is to be grilled, an input 50 sends a signal to a control 51 which sends a signal to the desired motor 45 c and 45 d to raise at least one of the respective platforms 38 c and 38 d in the feeding side 34 for removal of the food items 52 from the freezer component 22 . As the rotatable portion 28 has rotated 180°, the platforms 38 c and 38 d are located in the feeding side 34 and the platforms 38 a and 38 b are located in the loading side 32 . The food items 52 are alternately delivered from the platforms 38 c and 38 d for removal from the freezer component 22 . For example, after the input 50 sends a signal indicating a request to grill a food item 52 , platform 38 c rises to position a food item 52 for removal from the freezer component 22 . When the food item 52 is raised, it is removed from the freezer component 22 by a removal device 90 and exits through the front slot 76 (shown in FIG. 5). When the next signal is received, platform 38 d rises to position another item of food 52 for removal from the freezer component 22 by the removal device 90 . A subsequent signal raises the platform 38 c , and so on.
[0020] Preferably, the input 50 includes a POS (point of service) register. When an item of food 52 is ordered by a customer, an operator inputs the order into the POS register. The POS register sends the signal to the control 51 , which responsively dispenses the desired number of food items 52 . Alternatively, an operator inputs into the input 50 the numbers of food items 52 that are to be dispensed.
[0021] The platforms 38 c and 38 d rise until all the food items 52 in the feeding area 34 are removed. When the upper sensor 42 senses that both of the platforms 38 c and 38 d are positioned in an empty position, that is, the platforms 38 c and 38 d are in a position where all of the food items 52 are removed, the feeding side 34 is empty. The carousel 30 then rotates the rotatable portion 28 180° in an opposing direction. If the carousel 30 over-rotates, the projection 46 engages the other stop 47 (shown in FIG. 3) to prevent over-rotation. A sensor 49 monitors the position of the carousel 30 and communicates to the carousel 30 when to stop rotating.
[0022] Rotation in the opposition direction positions the platforms 38 a and 38 b loaded with the food items 52 in the feeding side 34 , and the platforms 38 c and 38 d holding no food items 52 in the loading side 32 . During rotation, the platforms 38 c and 38 d in the loading side 32 lower so they are ready to receive additional food items 52 . When the lower sensor 44 senses the platforms 38 c and 38 d are lowered and in the loading position, the freezer component 22 knows that the loading side 32 is ready for loading of additional food items 52 .
[0023] Preferably, the upper sensor 42 and the lower sensor 44 are magnetic reed switches and the platforms 38 a , 38 b , 38 c , and 38 d include a magnet. When the upper sensor 42 or lower sensor 44 sense the magnet, the sensors 42 or 44 detect the platforms 38 a , 38 b , 38 c and 38 d and can determine if the platforms 38 a , 38 b , 38 c and 38 d are in the loading portion or in the empty position.
[0024] After all the food items 52 are removed from the feeding side 34 of the freezer component 22 , the platforms 38 c and 38 d are in the empty position. When the upper sensor 42 senses the magnet in the platforms 38 c and 38 d in the feeding side 34 , the upper sensor 42 knows that the platforms 38 c and 38 d are in the empty position. The upper sensor 42 through the control 51 provides a signal to the motor 43 to rotate the carousel 30 and to the motors 45 c and 45 d of the respective empty platforms 38 c and 38 d to lower the platforms 38 c and 38 d . Therefore, the platforms 38 c and 38 d will be in the loading position once in the loading side 32 . Once the platforms 38 c and 38 d are in the loading position in the loading side 32 , the lower sensor 44 detects the magnets. Although magnetic sensors have been described, it is to be understood that other types of sensors 42 and 44 can be employed.
[0025] As shown in FIG. 4, a ring 54 a , 54 b , 54 c and 54 d is secured to the top of the rotatable portion 28 in each of the respective four surfaces 36 a , 36 b , 36 c and 36 d . The rings 54 a , 54 b , 54 c and 54 d each include an inner aperture 56 a , 56 b , 56 c , and 56 d sized to allow passage of the food items 52 . The rings 54 a , 54 b , 54 c and 54 d assist in guiding the stack of the food items 52 as the platforms 38 a , 38 b , 38 c and 38 d lift and funnel the food items 52 for removal from the freezer component 22 . In one example, the rings 54 a , 54 b , 54 c and 54 d have a height which is sized to receive several food items 52 at once.
[0026] Alternatively, the freezer component 22 does not include a carousel 30 and a feeding side 34 . The food items 52 are both loaded into the freezer component 22 and removed from the freezer component 22 in the loading side 32 . The food items 52 can be loaded into the loading side 32 in a cartridge which contains a plurality of food items 52 to expedite the loading process.
[0027] As shown in FIG. 5, the freezer component 22 is enclosed by a housing 58 including a door 60 . When the door 60 is opened, an operator can access the loading side 32 (shown in FIG. 1) of the freezer component 22 through an access opening 62 during operation. The example freezer component 22 further includes an interlock 64 which prevents rotation of the rotatable portion 28 when the door 60 is opened.
[0028] Additionally, the frozen food items 52 can be placed in the freezer component 22 in cartridges which contain several food items 52 , reducing crew labor in loading.
[0029] The freezer component 22 of the present invention can be used with an automated grill, such as described in co-pending patent application Ser. No. ______ entitled “Automated grill” filed on ______.
[0030] The foregoing description is only exemplary of the principles of the invention. Many modifications and variations are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than using the example embodiments which have been specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.
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A freezer component stores and removes frozen food in response to a signal. The freezer component includes a rotatable portion, a loading side and a feeding side. Two raiseable platforms are located in each of the loading side and the feeding side. Food is loaded into the freezer component by placing food onto the platforms positioned in the loading side. The rotatable portion then rotates 180° to position the food-loaded platforms in the feeding side. The empty platforms now located in the loading side are loaded with additional food. When a signal is received, food in the feeding side is removed from the freezer component by alternately raising the two platforms holding the food. When the feeding side is empty and contains no more food, the rotatable portion rotates 180° in the reverse direction. The food loaded platforms are now located in the feeding side. The empty platforms are located in the loading side and ready for loading of additional food.
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BACKGROUND OF THE INVENTION
This invention relates generally to a system for controlling the on/off point and the direction of rotation of a vibratory device in a vibratory compactor, and more particularly to a system utilizing signals from speed sensing and direction sensing devices on the compactor to automatically turn the vibratory device on and off at a given speed and to automatically set the direction of rotation of the vibratory device depending upon the forward or reverse direction of movement of the compactor.
Prior art devices for controlling the on/off point and the direction of rotation of a vibratory device use mechanical connections, such as cables extending between the vehicle's propulsion lever and switches and other activating devices. Over time, mechanical connections become worn and out of adjustment, causing improper operation that leads to inconsistent compaction.
The foregoing illustrates limitations known to exist in present vibratory control systems. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.
SUMMARY OF THE INVENTION
In one aspect of the present invention, this is accomplished by providing a system for controlling a vibratory mechanism on a vibratory compaction vehicle comprising: a first vehicle frame portion mounted on a front driving member rotatably connected to a first transverse axle; a second vehicle frame portion mounted on a rear driving member rotatably connected to a second transverse axle parallel to said first axle, said first and second frame portions being connected together; propulsion means for propelling said vehicle including a first hydraulic motor means for rotating one of said driving members; vibration means mounted on said one driving member for causing vibratory impacts to be transmitted by said one driving member to material to be compacted thereunder; means for determining a longitudinal speed of movement of said vehicle; and means for turning said vibratory mechanism on and off, when said horizontal speed is within a preselected range.
The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a schematic, partly cross-sectional elevational side view of the compactor of this invention;
FIG. 2 is a schematic, partly cross-sectional plan view of the compactor of this invention; and
FIG. 3 is a block diagram of the signal flow of the present invention in accordance with which signals are generated and processed, to control a vibratory device based upon speed and direction of movement of the compactor of this invention.
FIG. 4 is a schematic elevational view showing a movement sensing arrangement for a compactor of this invention;
FIG. 5 is a view along 5--5 of FIG. 4;
FIG. 6 is an alternate embodiment of a movement sensing arrangement for the compactor of this invention;
FIG. 7 is an expanded view of the circled area of FIG. 6; and
FIG. 8 is a view along 8--8 of FIG. 6.
DETAILED DESCRIPTION
FIGS. 1 and 2 show a conventional mobile asphalt compacting vehicle 1 having a first vehicle frame portion 3 mounted on a steel drum front driving member 5, which is rotatably connected to a first transverse axle 7, as is well known. A second vehicle frame portion 9 is mounted on a rear steel drum driving member 11, which is also rotatably connected to a second transverse axle 13 parallel to axle 7. First and second frame portions are connected to each other by an articulated joint 15, as is well known, although a rigid connection can also be used. Carried on first frame portion 3 is an operator station of conventional design, including a seat 22, a safety rail 24, and a steering wheel 28, whereby steering mechanism 30 is actuated. Mounted on vehicle 1 is a vibration control microprocessor 26, as described hereinafter.
Propulsion means for propelling the vehicle 1 includes first hydraulic motor 40 for rotating front driving member 5. Motor 40 and its operative connection to driving member 5 are conventional and well known. Propulsion lever 42 is used by a machine operator (not shown) to control the forward or reverse direction of the vehicle, as well as the speed in either forward or reverse, as is conventional and well known.
Mounted on front driving member 5 is a conventional rotary vibration means 44 for causing vibratory impacts to be transmitted by front driving member 5 to material to be compacted thereunder. Vibration means 44 is driven by a second hydraulic motor 46. Motor 46 and its operative connection to driving member 5 are conventional and well known. Motor 46 can be operated in a forward or a reverse direction to cause the eccentrically mounted vibratory means 44 to operate in a forward or reverse direction, corresponding to the direction of travel of vehicle 1, as is well known. We prefer to operate motor 46 and vibration means 44 in the same direction as the movement of the vehicle 1. Thus, when the vehicle 1 is moving forward, the vibration means is rotated in a forward direction, and when the vehicle 1 is moving rearwardly, the vibration means 44 is rotated in a reverse direction. A vibratory compactor that coincides the direction of vehicle movement and direction of vibratory rotation exhibits reduced tractive effort to ride up onto a mat of material to be compacted, providing better compaction.
We have shown a double drum compactor, but this invention will work with a single drum compactor. With a double drum compactor, a third hydraulic motor 48 rotates rear driving member 11. It is also optional to provide a vibration means 44, 46 on either or both front and rear driving members 5, 11. For a double drum compactor, we prefer a vibration means 44 on both front and rear driving members 5,11.
Referring to FIGS. 4 and 5, means for controlling the on/off point of a vibration means 44 in vehicle 1 will now be described. Hydraulic motor 40 interacts with a speed reducer 50 having a plurality of gear teeth 52 rotating about axle 7 of drum 5. A sensing device 54 induces a magnetic field through which gear teeth 52 move. As each gear tooth 52 and its adjacent gap moves through the magnetic field, sensing device 54 detects an intermittent change in magnetic field flux as a plurality of intermittent events herein termed "pulses", caused by the presence and absence of the metal gear tooth. These "pulses" are transmitted as a plurality of intermittent electrical signals to microcontroller 26.
Referring to FIGS. 6, 7 and 8, an alternate embodiment of means for controlling the on/off point of a vibration means 44 in vehicle 1 will now be described. An annular pick-up ring 70 is mounted adjacent speed reducer 50 on axle 7, for rotating with axle 7. Axle 7 is supported by frame member portion 71, as is conventional. Ring 70 has a plurality of teeth 72 formed on its outside diameter. Sensing device 54 induces the magnetic field through which the teeth 72 move. As each gear tooth 72 and its adjacent gap moves through the magnetic field, sensing device 54 detects an intermittent change in magnetic field flux as a plurality of intermittent "pulses", caused by the presence and absence of the metal gear tooth. These "pulses" are transmitted as a plurality of intermittent electrical signals to microcontroller 26.
In either embodiment, simultaneously with the action of sensing device 54, a timing clock 60 (FIG. 3) transmits a timing signal to microcontroller 26. Microcontroller 26 includes a microchip, programmed to convert the "pulsed" electrical signal and the timing signal into a number herein called "Sensor Input Frequency", stated in cycles per second (hereinafter called "Hz"). Microcontroller 26 relates the Sensor Input Frequency number to a vehicle longitudinal speed in miles per hour. Examples I-IV show the algorithm used by microprocessor 26 to perform the calculations herein described for various diameters of drum 5.
Other types of speed determining devices can be used, such as radar impinging on the ground, or other optical devices to sense the "pulses" of moving teeth 52, 72, or other moving elements on vehicle 1.
EXAMPLE I
DD-65 Machine Speed vs. Sensor Frequency
Drum Dia.: 41.3 in.
π=C/D C=πD
Sensor Input Freq. (Hz)=(a mi./hr.)(5280 ft./mi.) (12 in./ft.) (1 hr./60 min.) (1 drum rev./π 41.3 in.!) (1 min./60 sec.) (1 motor rev./drum rev.) (56 pulses/motor rev.)
Sensor Input Frequency (Hz)=(a mi./hr.) (7.60)
______________________________________Machine Travel Speed (mi./hr.) Sensor Input Frequency (Hz)______________________________________.2 1.52.3 2.28.4 3.04.5 3.80.6 4.56.7 5.32.8 6.08.9 6.841.0 7.60______________________________________
EXAMPLE II
DD-130 Machine Speed vs. Sensor Frequency
Drum Dia.: 1400 mm (55.1 in.)
π=C/D C=πD
Sensor Input Freq. (Hz)=(a mi./hr.) (5280 ft./mi.) (12 in./ft.) (1 hr./60 min.) (1 drum rev./π 55.1 in.!) (1 min./60 sec.) (1 motor rev./drum rev.) (60 pulses/motor rev.)
Sensor Input Frequency (Hz)=(a mi./hr.) (6.10)
______________________________________Machine Travel Speed (mi./hr.) Sensor Input Frequency (Hz)______________________________________.2 1.22.3 1.83.4 2.44.5 3.05.6 3.66.7 4.27.8 4.88.9 5.491.0 6.10______________________________________
EXAMPLE III
DD-90 Machine Speed vs. Sensor Frequency
Drum Dia.: 48 in.
π=C/D C=πD
Sensor Input Freq. (Hz)=(a mi./hr.) (5280 ft./mi.) (12 in./ft.) (1 hr./60 min.) (1 drum rev./π 48 in.!) (1 min./60 sec.) (34.62 motor rev./drum rev.) (28 pulses/motor rev.)
Sensor Input Frequency (Hz)=(a mi./hr.) (113.14)
______________________________________Machine Travel Speed (mi./hr.) Sensor Input Frequency (Hz)______________________________________.2 22.62.3 33.94.4 45.26.5 56.57.6 67.88.7 79.20.8 90.51.9 101.821.0 113.14______________________________________
EXAMPLE IV
DD-110 Machine Speed vs. Sensor Frequency
Drum Dia.: 54 in.
π=C/D C=πD
Sensor Input Freq. (Hz)=(a mi./hr.) (5280 ft./mi.) (12 in./ft.) (1 hr./60 min.) (1 drum rev./π 54 in.!) (1 min./60 sec.) (34.62 motor rev./drum rev.) (28 pulses/motor rev.)
Sensor Input Frequency (Hz)=(a mi./hr.) (100.57)
______________________________________Machine Travel Speed (mi./hr.) Sensor Input Frequency (Hz)______________________________________.2 20.1.3 30.2.4 40.2.5 50.3.6 60.3.7 70.4.8 80.5.9 90.51.0 100.6______________________________________
Microcontroller 26 is programmed to receive an input signal from an operator selector switch 64 (FIG. 3), which signal selects a machine travel speed range wherein the microcontroller will activate vibration devices 44. When the machine travel speed is within the range, a vibration device activating signal is generated by microcontroller 26 and transmitted to electro-hydraulic valve means 66, 68 to activate vibration device 44 on drums 5, 11, either in the forward or reverse direction as described hereinafter.
Means for sensing the direction of movement of vehicle 1 and for thereafter controlling the direction of rotation of motor 48 in vibration means 44 will now be described. A transducer switch 80 is operably connected to propulsion leyer 42. Switch 80 is a normally open switch, and thus will continuously permit the microcontroller 26 to indicate a forward direction to vibration device 44. Switch 80 is only closed when the propulsion lever 42 is in the reverse position, and in the closed position, switch 80 generates a reverse direction electrical signal. In the forward direction, microcontroller 26 transmits a first vibration activation signal to a first electro-hydraulic valve 66 that operates motor 46 of vibration means 44 on drums 5, 11 in a forward direction. Reverse direction signal causes microcontroller 26 to transmit a second vibration activation signal to a second electro-hydraulic valve 68 that operates motor 46 of vibration means 44 on drums 5, 11 in a reverse direction. It can be understood that this automatic selection of direction of operation of motor can be eliminated, with such signals being manually input, and only the start/stop points being automatic. We prefer the automatic directional operation together with the automatic start/stop.
FIG. 3 shows a schematic block diagram of the signal flow of the present invention in accordance with which signals are generated and processed, to activate vibration means 44. FIG. 3 shows an arrangement having a motor 40, 48 on members 5, 11, respectively, plus a vibration means 44 on front and rear driving members 5, 11. Microcontroller 26 can include a plurality of microchips, each microchip programmed for one drum size, or, alternatively, a single microchip can be programmed with a plurality of programs for various size drums. Each program can be selectively activated by a signal manually input from a machine model selector switch 72. Optionally, microcontroller 26 can generate a speed display signal that is transmitted to a speed display device 62 visible to an operator.
Techniques for programming microchips described herein are conventional and well known. The major elements of this apparatus are readily available.
For motor 40, we prefer a motor from Sauer Sundstrand Company, series 90 designation or a motor from Poclain Hydraulics, Inc., designation T36. For motor 46, we prefer a series 90 motor from Sauer Sundstrand Company. For speed sensor 54, we prefer speed sensor part number 727573-02 from the Electro Corporation. For microcontroller 26, we prefer a Motorola Corporation microcontroller, part number MC68HC7057J2.
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A vibratory compactor includes front and rear frame portions driven by a first hydraulic motor and a vibration mechanism on at least one of the frame portions also driven by a second hydraulic motor. A first sensor on the vehicle senses movement of a member on said vehicle driven by said first hydraulic motor, and sends corresponding signals to a microcontroller on the vehicle. A timing device sends timing signals to the microcontroller, which is programmed to convert the movement signals and timing signals to indicate longitudinal speed of travel of the vehicle. The microcontroller automatically turns a vibration means on the vehicle on or off depending on the speed of the vehicle. A second sensor on the vehicle sends a signal to the microcontroller indicating a reverse direction of travel of the vehicle. The microcontroller automatically coincides the direction of motion of the vibration means with the direction of travel of the vehicle.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application is based upon U.S. Provisional Patent Application No. 61/891,734, filed Oct. 16, 2013, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention addresses a recent need in the consumer product industry regarding the increasing size of premium paper goods, e.g., tissue and towel, and concurrently their packages. As papermaking techniques have improved and the industry has moved to structured base sheets, the attributes of tissue and towel have improved. These improvements are seen in characteristics like softness, bulk, and absorbency of the paper, among others. However, concurrent with these improvements, the tissue plies have also become thicker making rolls of paper, e.g., towels and bathroom tissue, larger. These larger rolls require additional space to store and ship. In addition, while the roll products have gotten larger, consumer carriers have not. Consumers neither wish to change the size of their bathroom tissue or paper towel holders nor do they want to receive smaller rolls containing less paper product. Therefore, a need exists for a paper product that has reduced bulk and increased density that can achieve the consumer's desired size without either requiring reduction of the amount of product or compromising the properties of the paper product.
SUMMARY OF THE INVENTION
[0003] This disclosure provides a method of increasing the density and reducing the bulk of paper products, thus allowing one to reduce the roll size or increase the roll content of a product made from that paper, while minimizing impact on favorable product attributes. Specifically, the method of this disclosure uses a substantially linear emboss pattern which decreases the bulk of the product without interfering with important consumer characteristics such as strength and absorbency. This disclosure further relates to the paper products having increased density and reduced bulk made by this method. According to one embodiment, this disclosure provides a method of embossing and plying a multi-ply product.
[0004] Products such as paper towels, bathroom tissue, facial tissues, napkins, wipers, and like products, are typically made from one or more webs of nonwoven paper. For the products to perform as expected by the consumer, the webs from which these products are formed generally exhibit favorable characteristics of strength, softness, and absorbency. Strength is the ability of a paper web to retain its physical integrity during use. Softness is the pleasing tactile sensation the consumer perceives as the consumer uses the paper product. Absorbency is the characteristic of the paper web which allows it to take up and retain fluids. Typically, the softness and/or absorbency of a paper web increases at the expense of the strength of the paper web. Consumer testing of products having embossed surfaces show that consumers prefer soft products with relatively high caliper (thickness) and exhibiting aesthetically pleasing decorative patterns. The products of the instant disclosure achieve all of the consumer's desired attributes while having a reduced bulk.
[0005] Processes for the manufacture of wet-laid paper products generally involve the preparation of an aqueous slurry of cellulosic fibers and subsequent removal of water from the slurry while rearranging the fibers to form a web. Various types of machinery can be employed to assist in the dewatering process. A typical manufacturing process employs, for example, a Fourdrinier wire papermaking machine where a paper slurry is fed onto a surface of a traveling endless wire where the initial dewatering occurs. In a conventional wet press process, the fibers are transferred directly to a capillary de-watering belt where additional de-watering occurs. In a structured web process, the fibrous web is subsequently transferred to a papermaking belt where rearrangement and drying of the fibers is carried out.
[0006] As paper production has moved from conventional wet pressing to through air drying (TAD) and other methods for making structured base sheets, for example, using a perforated polymeric belt as described in U.S. Pat. No. 8,293,072, the tissue base sheets have seen improvements in many sheet characteristics including strength, softness, bulk, and absorbency. As the caliper of these structured base sheets has increased, either package size has increased or the sheet count has been reduced. A need exists for a reduced bulk premium paper product exhibiting uncompromised quality which would mirror current commercial products in size and sheet count. Heretofore, embossing and plying were routinely carried out to increase and improve the bulk and absorbency of a paper product. Embossing is known to increase the bulk of the product to which it is applied. It is therefore surprising that an embossing pattern made up of substantially linear elements can be used to emboss, or emboss and ply, a premium paper product without compromising quality but resulting in an end product having a caliper lower than the caliper of the nonwoven web(s) from which it is made.
[0007] Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
[0008] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. The accompanying drawings, which 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
[0009] FIGS. 1A and 1B illustrate an emboss pattern that can be used in the method according to the invention, and its counterpart non-linear dot representation, respectively.
[0010] FIGS. 2A and 2B illustrate an emboss pattern that can be used in the method according to the invention, and its counterpart non-linear dot representation, respectively.
[0011] FIGS. 3A and 3B illustrate an emboss pattern that can be used in the method according to the invention, and its counterpart non-linear dot representation, respectively.
[0012] FIGS. 4A and 4B illustrate an emboss pattern that can be used in the method according to the invention, and its counterpart non-linear dot representation, respectively.
[0013] FIGS. 5A and 5B illustrate an emboss pattern that can be used in the method according to the invention, and its counterpart non-linear dot representation, respectively.
[0014] FIGS. 6A and 6B illustrate an emboss pattern that can be used in the method according to the invention, and its counterpart non-linear dot representation, respectively.
[0015] FIGS. 7A and 7B illustrate an emboss pattern that can be used in the method according to the invention, and its counterpart non-linear dot representation, respectively.
[0016] FIGS. 8A and 8B illustrate an emboss pattern that can be used in the method according to the invention, and its counterpart non-linear dot representation, respectively.
[0017] FIG. 9 illustrates an emboss pattern that can be used in the method according to the invention.
[0018] FIGS. 10 to 22 are graphical representations based upon the data presented in Example 2.
DETAILED DESCRIPTION OF THE INVENTION
[0019] As used herein, the terms “paper web,” “web,” “paper sheet,” “fibrous structure,” “nonwoven web,” and “paper product” are all used interchangeably to refer to sheets of paper products suitable for consumer use in, for example, paper toweling, bath tissue, napkins, facial tissue, wipers and the like. Products of the disclosure can be any paper product in which the bulk and density of the product would benefit from reduction and in which it is important that softness, absorbency and strength not be substantially negatively affected. Products contemplated for production using the disclosed embossing method can be in the areas of tissue and towel, feminine hygiene, adult incontinence and baby products, including, for example, baby wipes or diapers. The paper products as described can be in the form of, for example, stacks or rolls. In one embodiment, the paper products as described may be wound with or without a core to form a rolled paper product. Rolled products may comprise a plurality of connected and perforated sheets that are separable and dispensable from adjacent sheets.
[0020] The paper of the present invention may comprise papermaking fibers of both hardwoods and softwoods pulps. “Hardwood pulps” as used herein refers to fibrous pulp derived from the woody substance of deciduous trees (angiosperms). “Softwood pulps” are fibrous pulps derived from the woody substance of coniferous trees (gymnosperms). Blends of hardwood and softwood are also suitable to produce the paper products as described. In one embodiment the plies of the paper product may be heterogeneous web layers. In another embodiment, the plies may be non-heterogeneous or stratified. Also applicable to the present invention are fibers derived from recycled paper, which may contain any or all of the above categories of fibers. According to yet another embodiment, the fibers may include one or more non-wood based fiber. Wood pulps useful herein include chemical pulps such as, sulfite and sulfate (sometimes called Kraft) pulps as well as mechanical pulps including for example, ground wood, ThermoMechanical Pulp (TMP) and Chemi-ThermoMechanical Pulp (CTMP).
[0021] Paper products of the present disclosure may be produced according to any art recognized wet laid or air laid method. According to one embodiment, the paper product as described is made from one or more base sheet(s) chosen from conventional wet press (CWP) base sheet(s), structured base sheet(s) including both TAD and e-TAD, air laid base sheet(s) and combinations thereof.
[0022] Any art recognized process for making the base sheet(s) is suitable for use in the present invention. Typically, depending upon the desired end use, paper products are generally comprised of papermaking fibers and small amounts of chemical functional agents such as wet strength or dry strength agents, binders, retention aids, surfactants, size, chemical softeners, and release agents. Additionally, filler materials may also be incorporated into the web. All such base sheets may be used in the method described in the instant disclosure.
[0023] The paper product of the present invention may exhibit a basis weight of from about 20 g/m 2 to about 120 g/m 2 , for example, from about 30 g/m 2 to about 65 g/m 2 , for example, from about 37 g/m 2 to about 50 g/m 2 .
[0024] Paper products as described are embossed. “Embossed” as used herein with respect to a fibrous web means a fibrous web that has been subjected to a process which converts a smooth surfaced fibrous web to a decorative surface by replicating a design on one or more emboss rolls, which form a nip through which the fibrous web passes. Embossed does not include creping, microcreping, printing or other processes that may impart a texture and/or decorative pattern to a fibrous structure.
[0025] During a typical embossing process, a web is fed through a nip formed between juxtaposed generally axially parallel rolls. Embossing elements on the rolls compress and/or deform the web. If a multi-ply product is being formed, two or more webs, i.e., plies, are fed through the nip and regions of each ply are brought into a contacting relationship with the opposing ply. The embossed regions of the plies produce an aesthetic pattern and may provide a means for joining and maintaining the plies in face-to-face contacting relationship.
[0026] Generally, the embossing apparatus will include one or more rolls having protuberances and/or depressions formed therein. A corresponding backup roll presses the web against the embossing roll such that the embossed pattern is imparted to the web as it passes between the nip formed between the embossing roll and the backup roll. Any art recognized embossing configuration can be used in the method of the present disclosure.
[0027] While fiber-to-steel, steel-to-steel or rubber-to-rubber embossing operations can be used, the most common embossing configuration is rubber-to-steel. In rubber-to-steel embossing, the steel embossing roll is provided with protuberances and/or depressions and the web is pressed against the embossing roll by a rubber backing roll as the web passes through the nip formed between the rubber and the steel rolls. The rubber backing roll accommodates the protuberances and/or depressions by virtue of its resilience and the rubber flows about the protuberances and/or depressions as force is applied to urge the rolls together. An alternative rubber-to-steel configuration is a mated configuration. This configuration mates a steel embossing roll having a plurality of protuberances extending therefrom with a patterned rubber backing roll which urges the fibrous web substrate against the embossing roll thereby imparting a highly defined embossed pattern to the paper substrate for forming paper towels, napkins or tissues. As the paper substrate passes through the nip between the rolls, the web is forced about the protuberances and against the land areas of the steel roll, as well as into the indentations and outer peripheral surfaces of the rubber roll. As a result, a highly defined embossed pattern is provided. According to one embodiment of the invention, the embossing operation is a rubber to steel configuration.
[0028] The paper products as disclosed bear an emboss pattern that comprises linear embossments. A linear embossment is characterized by having a total embossment length to total embossment width (or an aspect ratio) of at least about 5. Smaller, embossments having an aspect ratio of less than 5 are referred to herein as dot embossments; however they can take any shape. According to one embodiment, linear embossments make up at least about 80% or the embossments on the paper product, for example, at least about 90%, for example at least about 95%. According to one embodiment, the emboss pattern is made up solely (100%) of linear emboss elements.
[0029] According to one embodiment, the linear emboss elements have an aspect ratio of at least about 5, for example, at least about 10, for example, at least about 20, for example, at least about 30, for example, at least about 40, for example, at least about 50.
[0030] According to another embodiment, the depth of embossments are from about 1.25 to about 3.5 times the caliper of the unembossed base sheet(s), for example, about 1.5 to about 2.5 times, for example, from about 1.5 to about 2.0. In the embodiment where two plies are used, this is sufficient to maintain good ply lamination with a consumer preferred appearance while reducing the finished product caliper to something less than the expected caliper of the two unembossed plies combined. This allows for the production of high performance structured base sheet products with a higher finished product density. Embossing depths for use in the present invention are generally at least about 30 mm (762 μm), for example, at least about 35 mm (889 μm), for example, at least about 40 mm (1016 μm) at least about 45 mm (1143 μm), for example, at least about 50 mm (1270 μm). As described herein embossing depth corresponds to the height of the majority elements on the emboss roll.
[0031] Without wishing to be bound by theory, we believe the linear elements, coupled with the defined depth of embossment provide more surface area, which minimizes the impact on sheet properties while resulting in an aesthetically pleasing product that can be packaged in the desired size, e.g., wound to the desired roll size, without giving up sheet count.
[0032] According to one embodiment, the embossments cover greater than about 22%, for example, from about 22 to about 50%, for example, from about 25 to about 50%, for example about 22 to about 30% of the total area of the finished product.
[0033] A multitude of combinations of emboss coverage, emboss depth, emboss aspect ratio and percent linear embosses would be apparent to the skilled artisan. The combinations set forth below are merely exemplary.
[0034] According to one embodiment, the paper products bearing the linear emboss pattern exhibit at least about 1% less caliper than the base sheet(s), for example, at least about 1.5% less caliper, for example, at least about 2% less caliper, for example, at least about 2.5% less caliper, for example, at least about 3% less caliper, for example at least about 3.5% less caliper, for example, at least about 4% less caliper, for example, at least about 4.5%, for example, at least about 5% less caliper.
[0000]
TABLE 1
Emboss Aspect Ratio
of linear
embossments and
Percent of overall
percentage of linear
pattern that is
Emboss
Emboss
embossments at that
made up of linear
Coverage (%)
Depth (mils)
Aspect ratio
embossments
22 to 50
At least 35
At least 5-100%
At least 80
22 to 50
At least 40
At least 5-100%
At least 80
22 to 50
At least 45
At least 5-100%
At least 80
22 to 50
At least 55
At least 5-100%
At least 80
22 to 50
At least 35
At least 5-100%
At least 90
22 to 50
At least 40
At least 5-100%
At least 90
22 to 50
At least 45
At least 5-100%
At least 90
22 to 50
At least 55
At least 5-100%
At least 90
22 to 50
At least 35
At least 5-100%
100
22 to 50
At least 40
At least 5-100%
100
22 to 50
At least 45
At least 5-100%
100
22 to 50
At least 55
At least 5-100%
100
22 to 50
At least 35
At least 10-100%
At least 80
22 to 50
At least 40
At least 10-100%
At least 80
22 to 50
At least 45
At least 10-100%
At least 80
22 to 50
At least 55
At least 10-100%
At least 80
22 to 50
At least 35
At least 10-100%
At least 90
22 to 50
At least 40
At least 10-100%
At least 90
22 to 50
At least 45
At least 10-100%
At least 90
22 to 50
At least 55
At least 10-100%
At least 90
22 to 50
At least 35
At least 10-100%
100
22 to 50
At least 40
At least 10-100%
100
22 to 50
At least 45
At least 10-100%
100
22 to 50
At least 55
At least 10-100%
100
22 to 50
At least 35
At least 20-100%
At least 80
22 to 50
At least 40
At least 20-100%
At least 80
22 to 50
At least 45
At least 20-100%
At least 80
22 to 50
At least 55
At least 20-100%
At least 80
22 to 50
At least 35
At least 20-at least
At least 80
80%
22 to 50
At least 40
At least 20-at least
At least 80
80%
22 to 50
At least 45
At least 20-at least
At least 80
80%
22 to 50
At least 55
At least 20-at least
At least 80
80%
22 to 50
At least 35
At least 30-at least
At least 80
50%
22 to 50
At least 40
At least 30-at least
At least 80
50%
22 to 50
At least 45
At least 30-at least
At least 80
50%
22 to 50
At least 55
At least 30-at least
At least 80
50%
22 to 50
At least 35
At least 30-at least
At least 90
50%
22 to 50
At least 40
At least 30-at least
At least 90
50%
22 to 50
At least 45
At least 30-at least
At least 90
50%
22 to 50
At least 55
At least 30-at least
At least 90
50%
22 to 50
At least 35
At least 20-at least
At least 95
80%
22 to 50
At least 40
At least 20-at least
At least 95
80%
22 to 50
At least 45
At least 20-at least
At least 95
80%
22 to 50
At least 55
At least 20-at least
At least 95
80%
22 to 50
At least 35
At least 40-at least
At least 80
50%
22 to 50
At least 40
At least 40-at least
At least 80
50%
22 to 50
At least 45
At least 40-at least
At least 80
50%
22 to 50
At least 55
At least 40-at least
At least 80
50%
22 to 50
At least 35
At least 40-at least
At least 90
50%
22 to 50
At least 40
At least 40-at least
At least 90
50%
22 to 50
At least 45
At least 40-at least
At least 90
50%
22 to 50
At least 55
At least 40-at least
At least 90
50%
22 to 50
At least 35
At least 20-at least
100
50%
22 to 50
At least 40
At least 20-at least
100
50%
22 to 50
At least 45
At least 20-at least
100
50%
22 to 50
At least 55
At least 20-at least
100
50%
22 to 50
At least 35
At least 30-at least
100
50%
22 to 50
At least 40
At least 30-at least
100
50%
22 to 50
At least 45
At least 30-at least
100
50%
22 to 50
At least 55
At least 30-at least
100
50%
22 to 50
At least 35
At least 40-at least
100
50%
22 to 50
At least 40
At least 40-at least
100
50%
22 to 50
At least 45
At least 40-at least
100
50%
22 to 50
At least 55
At least 40-at least
100
50%
22 to 30
At least 35
At least 10-at least
100
50%
22 to 30
At least 40
At least 10-at least
100
50%
22 to 30
At least 45
At least 10-at least
100
50%
22 to 30
At least 55
At least 10-at least
100
50%
22 to 30
At least 35
At least 20-at least
100
50%
22 to 30
At least 40
At least 20-at least
100
50%
22 to 30
At least 45
At least 20-at least
100
50%
22 to 30
At least 55
At least 20-at least
100
50%
22 to 30
At least 35
At least 30-at least
100
50%
22 to 30
At least 40
At least 30-at least
100
50%
22 to 30
At least 45
At least 30-at least
100
50%
22 to 30
At least 55
At least 30-at least
100
50%
22 to 30
At least 35
At least 40-at least
100
50%
22 to 30
At least 40
At least 40-at least
100
50%
22 to 30
At least 45
At least 40-at least
100
50%
22 to 30
At least 55
At least 40-at least
100
50%
[0035] As seen from Table 1 above, the emboss configuration may vary. So, according to the first embodiment set forth in Table 1, the paper product would have 22 to 50% of its surface covered with embossments that are at least 35 mils high and where linear embossments make up at least 80% of the total embossments and 100% of the linear embossments have an aspect ratio of at least 5. And, according to the last embodiment set forth in Table 1, the paper product would have 22 to 30% of its surface covered with embossments that are at least 55 mils high and where linear embossments make up 100% of the total embossments and at least 50% of the linear embossments have an aspect ratio of at least 40.
[0036] According to one embodiment, the paper products bearing the linear emboss pattern exhibit at least about 5% less caliper than the same pattern formed from dots (See, FIG. 1A versus FIG. 1B ). According to another embodiment the paper products bearing the linear emboss pattern exhibit at least about 6% less caliper than the same pattern formed from dots, for example, at least about 8% less caliper, for example at least, about 10% less caliper, for example, at least about 12% less caliper.
[0037] FIG. 1A illustrates one pattern that may be used in the method of the present disclosure to reduce the bulk of the paper product. This pattern is made up of linear segments that are curved and flow around each other in a swirling pattern. FIG. 1B illustrates the pattern of FIG. 1A as it would be represented by dot embossments. FIGS. 2A , 3 A, 4 A, 5 A, 6 A, 7 A and 8 A illustrate other patterns that may be used in the method of the present disclosure to reduce the bulk of the paper product. FIGS. 2B , 3 B, 4 B 5 B 6 B, 7 B and 8 B illustrates the same patterns of FIGS. 2A , 3 A, 4 A, 5 A, 6 A, 7 A and 8 A, respectively, as they would be represented by dot embossments. FIG. 9 illustrates a pattern for use in the instant invention where the pattern is made up of linear segments of differing sizes.
[0038] As used herein, “about” is meant to account for variations due to experimental error. All measurements are understood to be modified by the word “about”, whether or not “about” is explicitly recited, unless specifically stated otherwise. Thus, for example, the statement “an emboss depth of at least 30 mm” is understood to mean “an emboss depth of at least about 30 mm.”
[0039] The details of one or more non-limiting embodiments of the invention are set forth in the examples below. Other embodiments of the invention should be apparent to those of ordinary skill in the art after consideration of the present disclosure.
EXAMPLES
[0040] The product characteristics measured in the Examples, infra, were measured according the following methodologies. Throughout this specification and claims, it is to be understood that, unless otherwise specified, physical properties are measured after the web has been conditioned according to Technical Association of the Pulp and Paper Industry (TAPPI) standards. If no test method is explicitly set forth for measurement of any quantity mentioned herein, it is to be understood that TAPPI standards should be applied.
Basis Weight
[0041] Unless otherwise specified, “basis weight”, BWT, bwt, BW, and so forth, refers to the weight of a 3000 square-foot ream of product (basis weight is also expressed in g/m 2 or gsm). Likewise, “ream” means a 3000 square-foot ream, unless otherwise specified. Likewise, “percent” or like terminology refers to weight percent on a dry basis, that is to say, with no free water present, which is equivalent to 5% moisture in the fiber.
Caliper
[0042] Caliper and/or bulk reported herein may be measured at 8 or 16 sheet calipers as specified. The sheets are stacked and the caliper measurement taken about the central portion of the stack. Preferably, the test samples are conditioned in an atmosphere of 23°±1.0° C. (73.4°±1.8° F.) at 50% relative humidity for at least about 2 hours and then measured with a Thwing-Albert Model 89-II-JR or Progage Electronic Thickness Tester with 2-in diameter anvils, 539±10 grams dead weight load, and 0.231 in/sec descent rate. For finished product testing, each sheet of product to be tested must have the same number of plies as the product as sold. For testing in general, eight sheets are selected and stacked together. For napkin testing, napkins are unfolded prior to stacking. For base sheet testing off of winders, each sheet to be tested must have the same number of plies as produced off of the winder. For base sheet testing off of the papermachine reel, single plies must be used. Sheets are stacked together aligned in the machine direction (MD). Bulk may also be expressed in units of volume/weight by dividing caliper by basis weight.
MD and CD Tensile, Stretch, Break Modulus and TEA
[0043] Dry tensile strengths (MD and CD), stretch, ratios thereof, modulus, break modulus, stress and strain are measured with a standard Instron test device or other suitable elongation tensile tester, which may be configured in various ways, typically, using 3 inch or 1 inch wide strips of tissue or towel, conditioned in an atmosphere of 23°±1.0° C. (73.4°±1.8° F.) at 50% relative humidity for 2 hours. The tensile test is run at a crosshead speed of 2 in/min. Break modulus is expressed in grams/3 inches/% strain or its SI equivalent of g/mm/% strain. % strain is dimensionless and need not be specified. Unless otherwise indicated, values are break values. GM refers to the square root of the product of the MD and CD values for a particular product. Tensile energy absorption (TEA), which is defined as the area under the load/elongation (stress/strain) curve, is also measured during the procedure for measuring tensile strength. Tensile energy absorption is related to the perceived strength of the product in use. Products having a higher TEA may be perceived by users as being stronger than similar products that have lower TEA values, even if the actual tensile strength of the two products are the same. In fact, having a higher tensile energy absorption may allow a product to be perceived as being stronger than one with a lower TEA, even if the tensile strength of the high-TEA product is less than that of the product having the lower TEA. When the term “normalized” is used in connection with a tensile strength, it simply refers to the appropriate tensile strength from which the effect of basis weight has been removed by dividing that tensile strength by the basis weight. In many cases, similar information is provided by the term “breaking length”.
[0044] GMT refers to the geometric mean tensile strength of the CD and MD tensile. Tensile energy absorption (TEA) is measured in accordance with TAPPI test method T494 om-01.
[0045] Tensile ratios are simply ratios of an MD value determined by way of the foregoing methods divided by the corresponding CD value. Unless otherwise specified, a tensile property is a dry sheet property.
Perforation Tensile
[0046] The perforation tensile strength (force per unit width required to break a specimen) is measured generally using a constant rate of elongation tensile tester equipped with 3-in wide jaw line contact grips. Typically, the test is carried out using 3 inch wide by 5 inch long strips of tissue or towel, conditioned in an atmosphere of 23°±1.0° C. (73.4°±1.8° F.) at 50% relative humidity for 2 hours. The crosshead speed of the tensile tester is generally set to 2.0 in. per minute. The jaw span is 3 inches. The specimen is clamped into the upper grip and allowed to hang freely. The lower grip is then used to grip the free end of the specimen tightly enough to hold the sample, but not with sufficient pressure to damage the sample. The sample is stretched until it breaks and the perforation tensile is recorded.
Wet Tensile
[0047] The wet tensile of the tissue of the present invention is measured generally following TAPPI Method T 576 pm 7, using a three-inch (76.2 mm) wide strip of tissue that is folded into a loop, clamped in a special fixture termed a Finch Cup, then immersed in water. A suitable Finch cup, 3-in., with base to fit a 3-in. grip, is available from:
[0048] High-Tech Manufacturing Services, Inc.
3105-B NE 65 th Street Vancouver, Wash. 98663 360-696-1611 360-696-9887 (FAX).
[0053] For fresh basesheet and finished product (aged 30 days or less for towel product, aged 24 hours or less for tissue product) containing wet strength additive, the test specimens are placed in a forced air oven heated to 105° C. (221° F.) for five minutes. No oven aging is needed for other samples. The Finch cup is mounted onto a tensile tester equipped with a 2.0 pound load cell with the flange of the Finch cup clamped by the tester's lower jaw and the ends of tissue loop clamped into the upper jaw of the tensile tester. The sample is immersed in water that has been adjusted to a pH of 7.0±0.1 and the tensile is tested after a 5 second immersion time using a crosshead speed of 2 inches/minute. The results are expressed in g/3 in., dividing the readout by two to account for the loop as appropriate.
Roll Compression
[0054] Roll compression is measured by compressing a roll under a 1500 g flat platen of a test apparatus. Sample rolls are conditioned and tested in an atmosphere of 23.0°±1.0° C. (73.4°±1.8° F.). A suitable test apparatus with a movable 1500 g platen (referred to as a height gauge) is available from:
[0055] Research Dimensions
1720 Oakridge Road Neenah, Wis. 54956 920-722-2289 920-725-6874 (FAX).
[0060] The test procedure is generally as follows:
(a) Raise the platen and position the roll to be tested on its side, centered under the platen, with the tail seal to the front of the gauge and the core parallel to the back of the gauge. (b) Slowly lower the platen until it rests on the roll. (c) Read the compressed roll diameter or sleeve height from the gauge pointer to the nearest 0.01 inch (0.254 mm). (d) Raise the platen and remove the roll. (e) Repeat for each roll or sleeve to be tested.
[0066] To calculate roll compression (RC) in percent, the following formula is used:
[0000]
RC
(
%
)
=
100
×
(
initial
roll
diameter
-
compressed
roll
diameter
)
initial
roll
diameter
SAT Capacity
[0067] Absorbency of the inventive products is measured with a simple absorbency tester. The simple absorbency tester is a particularly useful apparatus for measuring the hydrophilicity and absorbency properties of a sample of tissue, napkins, or towel. In this test, a sample of tissue, napkins, or towel 2.0 inches in diameter is mounted between a top flat plastic cover and a bottom grooved sample plate. The tissue, napkin, or towel sample disc is held in place by a ⅛ inch wide circumference flange area. The sample is not compressed by the holder. De-ionized water at 73° F. is introduced to the sample at the center of the bottom sample plate through a 1 mm. diameter conduit. This water is at a hydrostatic head of minus 5 mm. Flow is initiated by a pulse introduced at the start of the measurement by the instrument mechanism. Water is thus imbibed by the tissue, napkin, or towel sample from this central entrance point radially outward by capillary action. When the rate of water imbibation decreases below 0.005 gm water per 5 seconds, the test is terminated. The amount of water removed from the reservoir and absorbed by the sample is weighed and reported as grams of water per square meter of sample or grams of water per gram of sheet. In practice, an M/K Systems Inc. Gravimetric Absorbency Testing System is used. This is a commercial system obtainable from M/K Systems Inc., 12 Garden Street, Danvers, Mass., 01923. WAC, or water absorbent capacity, also referred to as SAT, is actually determined by the instrument itself. WAC is defined as the point where the weight versus time graph has a “zero” slope, i.e., the sample has stopped absorbing. The termination criteria for a test are expressed in maximum change in water weight absorbed over a fixed time period. This is basically an estimate of zero slope on the weight versus time graph. The program uses a change of 0.005 g over a 5 second time interval as termination criteria; unless “Slow SAT” is specified in which case the cut off criteria is 1 mg in 20 seconds.
[0068] Water absorbency rate is measured in seconds and is the time it takes for a sample to absorb a 0.1 gram droplet of water disposed on its surface by way of an automated syringe. The test specimens are preferably conditioned at 23°±1.0° C. (73.4°±1.8° F.) at 50% relative humidity. For each sample, 4 3×3 inch test specimens are prepared. Each specimen is placed in a sample holder such that a high intensity lamp is directed toward the specimen. 0.1 ml of water is deposited on the specimen surface and a stop watch is started. When the water is absorbed, as indicated by lack of further reflection of light from the drop, the stopwatch is stopped and the time recorded to the nearest 0.1 seconds. The procedure is repeated for each specimen and the results averaged for the sample. SAT Rate is determined by graphing the weight of water absorbed by the sample (in grams) against the square root of time (in seconds). The SAT rate is the best fit slope between 10 and 60 percent of the end point (grams of water absorbed).
Sensory Softness
[0069] Sensory softness of the samples was determined by using a panel of trained human subjects in a test area conditioned to TAPPI standards (temperature of 71.2° F. to 74.8° F., relative humidity of 48% to 52%). The softness evaluation relied on a series of physical references with predetermined softness values that were always available to each trained subject as they conducted the testing. The trained subjects directly compared test samples to the physical references to determine the softness level of the test samples. The trained subjects assigned a number to a particular paper product, with a higher sensory softness number indicating a higher the perceived softness.
Example 1
[0070] Paper towel base sheets were produced in a consistent manner and were either unembossed or embossed with either the current Brawny® non-linear embossing pattern of FIG. 5B or a linear pattern according to the present invention, i.e., the pattern of FIG. 5A and variations thereof. The characteristics for the unembossed base sheets and the two ply product are set forth in Table 2, below.
[0071] Table 3 sets forth the product characteristics for an embossed paper towel product bearing the current commercial, non-linear embossing pattern, both at a commercial emboss depth and at a depth of 45 mm. In Column 3 of Table 3 a comparison is made between the 45 mm embossed product and the unembossed base sheet described in Table 2. As can be seen from Table 3, column 3, the caliper of the product increased with embossing by 6.22%. The Wet Tensile strength remained largely unaffected.
[0072] Table 4 sets forth finished product characteristics for four paper towel products embossed with linear patterns according to the instant method. Table 5 compares those embossed product characteristics to the unembossed base sheet of Table 2. As can be seen in Table 5, when a paper towel was embossed with a substantially linear pattern as described herein, the caliper of the two ply product was less than the caliper of the two base sheets. As can also be seen from Table 5, the impact on sheet strength was minimal, if negative. In two instances, the CD wet tensile increased. Finally, while the absorbency of the final product did go down, the change in absorbency as reflected by the SAT capacity was always less than 10% and in some instances less than 5%. Accordingly, in this embodiment, an embossed paper product results having a lower caliper and higher density than the original base sheets and a significantly lower caliper than paper products embossed with a traditional non-linear pattern. In addition, the lower caliper and higher density do not result in changes in strength or sensory softness and only exhibit minor losses in absorbency.
[0000]
TABLE 2
Combined Base
Description
Ply 1
Ply 2
Sheet
Basis Weight lb/3000
13.55
13.45
27.00
ft 2
Caliper 8 Sheetmils/8
89.2
92.7
181.9
sht
Tensile MD g/3 in
1385.18
1569.31
2954.49
Stretch MD %
15.48
16.76
32.24
Tensile CD g/3 in.
1456.36
1478.55
2943.92
Stretch CD %
8.76
9.30
18.06
Tensile GM g/3 in.
1424.06
1522.78
2946.84
Tensile Dry Ratio
0.95
1.06
2.01
Unitless
Perf Tensile g/3 in.
424.63
415.16
839.78
Wet Tens Finch
0.29
0.28
0.57
Cured CD g/3 in.
Tensile Wet/Dry CD
Unitless
SAT Capacity g/m 2
530.96
SAT Rate g/s 0.5
SAT Times
Break Modulus MD
88.16
92.48
180.64
gms/%
Break Modulus CD
169.89
158.09
327.98
gms/%
Break Modulus GM
122.38
120.91
243.29
gms/%
Modulus MD g/%
Stretch
Modulus CD g/%
Stretch
Modulus GM g/%
Stretch
TEA MD mm-g/mm 2
1.37
1.62
2.99
TEA CD mm-g/mm 2
0.81
0.88
1.69
Roll Diameter In.
Roll Compression
Value %
Roll Compression in.
Basis Weight Raw
1.02
1.02
2.04
Wtg.
Sensory Softness
5.4
[0000]
TABLE 3
Current Product
Change from
Current
at a penetration
Basesheet based on
Description
Product
of 45 mm
45 mm penetration
Basis Weight lb/3000
26.57
26.29
−2.63
ft 2
Caliper 8 Sheetmils/8
195.05
193.22
6.22
sht
Tensile MD g/3 in
3083.12
3228.81
5.90
Stretch MD %
16.68
16.71
−48.61
Tensile CD g/3 in.
2837.73
2903.75
−1.36
Stretch CD %
10.03
10.04
−44.41
Tensile GM g/3 in.
2957.68
3013.46
2.26
Tensile Dry Ratio
1.09
1.08
−46.28
Unitless
Perf Tensile g/3 in.
732.25
725.78
Wet Tens Finch
813.27
840.26
0.06
Cured CD g/3 in.
Tensile Wet/Dry CD
0.29
0.29
−49.25
Unitless
SAT Capacity g/m 2
512.24
521.83
−1.72
SAT Rate g/s 0.5
0.26
0.31
SAT Times
42.03
35.31
Break Modulus MD
184.92
188.78
4.51
gms/%
Break Modulus CD
282.17
286.38
−12.69
gms/%
Break Modulus GM
228.39
232.47
−4.45
gms/%
Modulus MD g/%
41.55
42.65
Stretch
Modulus CD g/%
65.35
67.85
Stretch
Modulus GM g/%
52.08
53.78
Stretch
TEA MD mm-g/mm 2
3.13
3.17
6.10
TEA CD mm-g/mm 2
1.48
1.89
11.64
Roll Diameter In.
6.07
5.64
Roll Compression
3.15
3.72
Value %
Roll Compression in.
5.86
5.43
Basis Weight Raw
2.01
1.99
−2.63
Wtg.
Sensory Softness
5.60
5.7
[0000]
TABLE 4
Invention at Penetration of 45 mm
Description
Pattern A
Pattern B
Pattern C
Pattern D
Basis Weight
26.07
26.47
26.61
26.36
lb/3000 ft 2
Caliper 8
178.46
180.06
179.05
175.09
Sheetmils/8 sht
Tensile MD g/3 in
3000.08
3337.16
3086.51
3161.29
Stretch MD %
15.55
16.07
15.83
15.38
Tensile CD g/3 in.
2867.19
3185.83
2954.76
2911.81
Stretch CD %
9.55
9.66
9.46
9.44
Tensile GM g/3 in.
2931.82
3260.20
3019.6
3033.45
Tensile Dry Ratio
1.05
1.05
1.04
1.09
Unitless
Perf Tensile g/3 in.
706.15
727.19
709.54
604.07
Wet Tens Finch
822.45
844.51
856.00
809.51
Cured CD g/3 in.
Tensile Wet/Dry CD
0.29
0.27
0.29
0.28
Unitless
SAT Capacity g/m 2
498.4
491.19
493.76
487.84
SAT Rate g/s 0.5
0.25
0.24
0.27
0.26
SAT Times
35.62
32.22
29.41
28.87
Break Modulus MD
194.47
205.36
195.14
205.07
gms/%
Break Modulus CD
296.92
332.89
316.78
307.04
gms/%
Break Modulus GM
240.26
261.45
248.60
250.88
gms/%
Modulus MD g/%
45.80
50.38
45.43
49.37
Stretch
Modulus CD g/%
67.96
77.77
71.27
67.81
Stretch
Modulus GM g/%
55.76
62.59
56.89
57.82
Stretch
TEA MD mm-g/mm 2
2.90
3.44
3.08
3.02
TEA CD mm-g/mm 2
1.79
2.01
1.78
1.71
Roll Diameter In.
5.86
5.76
5.78
5.65
Roll Compression
4.21
5.27
5.48
4.96
Value %
Roll Compression in.
5.61
5.45
5.46
5.37
Basis Weight Raw
1.97
2.00
2.01
1.99
Wtg.
Sensory Softness
5.30
5.40
5.70
5.50
[0000]
TABLE 5
Invention at Penetration of 45 mm
(Percent Change from Basesheet)
Description
Pattern A
Pattern B
Pattern C
Pattern D
Basis Weight
−3.45
1.94
1.45
2.36
lb/3000 ft 2
Caliper 8
−1.89
−0.71
−1.57
−3.74
Sheetmils/8 sht
Tensile MD g/3 in
1.54
−12.95
−4.47
−7.00
Stretch MD %
−51.76
50.16
50.90
52.31
Tensile CD g/3 in.
−2.61
−8.22
−0.37
1.09
Stretch CD %
−47.11
46.49
47.63
47.72
Tensile GM g/3 in.
−0.51
−10.63
−2.47
−2.94
Tensile Dry Ratio
−47.85
47.79
49.22
51.25
Unitless
Perf Tensile g/3 in.
Wet Tens Finch
−2.06
0.56
1.93
−3.61
Cured CD g/3 in.
Tensile Wet/Dry CD
−49.72
53.53
49.22
51.25
Unitless
SAT Capacity g/m 2
−6.13
−7.49
−7.01
−8.12
SAT Rate g/s 0.5
SAT Times
Break Modulus MD
7.66
−13.69
−8.03
−13.53
gms/%
Break Modulus CD
−9.47
−1.49
3.41
6.39
gms/%
Break Modulus GM
−1.25
−7.46
−2.18
−3.12
gms/%
Modulus MD g/%
Stretch
Modulus CD g/%
Stretch
Modulus GM g/%
Stretch
TEA MD mm-g/mm 2
−2.77
−15.32
−3.00
−1.18
TEA CD mm-g/mm 2
5.91
−18.95
−5.50
−1.49
Roll Diameter In.
Roll Compression
Value %
Roll Compression in.
Basis Weight Raw
−3.45
1.94
1.45
2.36
Wtg.
Sensory Softness
Example 2
[0073] Example 2 was carried out in the same manner as Example 1, using an emboss penetration of 55 mils. Results are set forth in Tables 6-8, below.
[0000]
TABLE 6
Current Product
Change from
Current
at a penetration
Basesheet based on
Description
Product
of 55 mm
55 mm penetration
Basis Weight lb/3000
26.57
26.36
−2.38
ft 2
Caliper 8 Sheetmils/8
195.05
206.23
13.37
sht
Tensile MD g/3 in
3083.12
2865.60
−3.01
Stretch MD %
16.68
16.84
−47.76
Tensile CD g/3 in.
2837.73
2611.43
−11.29
Stretch CD %
10.03
10.22
−43.41
Tensile GM g/3 in.
2957.68
2735.26
−7.18
Tensile Dry Ratio
1.09
1.10
−45.33
Unitless
Perf Tensile g/3 in.
732.25
67.89
Wet Tens Finch
813.27
744.95
−11.29
Cured CD g/3 in.
Tensile Wet/Dry CD
0.29
0.29
−50.01
Unitless
SAT Capacity g/m 2
512.24
523.31
−1.72
SAT Rate g/s 0.5
0.26
0.33
SAT Times
42.03
40.06
Break Modulus MD
184.92
170.36
−5.69
gms/%
Break Modulus CD
282.17
253.72
−22.64
gms/%
Break Modulus GM
228.39
207.88
−14.55
gms/%
Modulus MD g/%
41.55
37.07
Stretch
Modulus CD g/%
65.35
57.73
Stretch
Modulus GM g/%
52.08
46.24
Stretch
TEA MD mm-g/mm 2
3.13
2.91
−2.58
TEA CD mm-g/mm 2
1.48
1.74
3.29
Roll Diameter In.
6.07
5.90
Roll Compression
3.15
4.80
Value %
Roll Compression in.
5.86
5.62
Basis Weight Raw
2.01
1.99
−2.38
Wtg.
Sensory Softness
5.60
6.1
[0000]
TABLE 7
Invention at Penetration of 55 mm
Description
Pattern A
Pattern B
Pattern C
Pattern D
Basis Weight
26.12
26.19
26.40
26.18
lb/3000 ft 2
Caliper 8
183.32
192.26
187.54
187.61
Sheetmils/8 sht
Tensile MD g/3 in
2793.50
2966.23
2880.07
2864.20
Stretch MD %
15.23
15.90
15.30
14.87
Tensile CD g/3 in.
2492.66
2688.85
2123.01
2501.79
Stretch CD %
9.58
9.52
9.50
8.97
Tensile GM g/3 in.
2638.12
2823.32
2799.58
2676.19
Tensile Dry Ratio
1.12
1.10
1.06
1.15
Unitless
Perf Tensile g/3 in.
624.56
682.48
647.34
704.59
Wet Tens Finch
717.31
762.97
790.76
733.06
Cured CD g/3 in.
Tensile Wet/Dry CD
0.29
0.28
0.29
0.29
Unitless
SAT Capacity g/m 2
481.81
499.80
499.30
494.75
SAT Rate g/s 0.5
0.20
0.26
0.26
0.28
SAT Times
44.07
31.98
29.71
26.31
Break Modulus MD
183.24
185.48
187.84
192.75
gms/%
Break Modulus CD
259.48
279.78
285.78
279.27
gms/%
Break Modulus GM
218.00
227.76
237.67
231.94
gms/%
Modulus MD g/%
46.40
42.64
42.75
42.76
Stretch
Modulus CD g/%
64.30
63.57
64.38
61.86
Stretch
Modulus GM g/%
54.59
52.04
52.43
51.39
Stretch
TEA MD mm-g/mm 2
2.67
2.94
2.72
2.62
TEA CD mm-g/mm 2
1.55
1.62
1.63
1.41
Roll Diameter In.
6.03
6.03
5.98
6.04
Roll Compression
4.59
6.63
6.41
6.90
Value %
Roll Compression in.
5.75
5.63
5.60
5.63
Basis Weight Raw
1.97
1.98
2.00
1.98
Wtg.
Sensory Softness
5.60
5.70
5.90
6.10
[0000]
TABLE 8
Invention at Penetration of 55 mm
(Percent Change from Basesheet)
Description
Pattern A
Pattern B
Pattern C
Pattern D
Basis Weight
−3.24
3.00
2.20
3.05
lb/3000 ft 2
Caliper 8
0.78
−5.69
−3.10
−3.14
Sheetmils/8 sht
Tensile MD g/3 in
−5.45
−0.40
2.52
3.06
Stretch MD %
−52.76
50.67
52.55
53.89
Tensile CD g/3 in.
−15.33
8.66
7.50
15.02
Stretch CD %
−46.97
47.28
47.41
50.31
Tensile GM g/3 in.
−10.48
4.19
5.00
9.18
Tensile Dry Ratio
−44.07
45.00
47.21
42.89
Unitless
Perf Tensile g/3 in.
Wet Tens Finch
−14.58
9.15
5.84
12.71
Cured CD g/3 in.
Tensile Wet/Dry CD
−49.54
50.26
49.09
48.63
Unitless
SAT Capacity g/m 2
SAT Rate g/s 0.5
SAT Times
Break Modulus MD
1.44
−2.68
−3.99
−6.70
gms/%
Break Modulus CD
−20.89
14.70
12.87
14.85
gms/%
Break Modulus GM
−10.40
6.38
4.78
4.67
gms/%
Modulus MD g/%
Stretch
Modulus CD g/%
Stretch
Modulus GM g/%
Stretch
TEA MD mm-g/mm 2
−10.50
1.62
9.00
12.21
TEA CD mm-g/mm 2
−8.44
3.90
3.70
16.75
Roll Diameter In.
Roll Compression
Value %
Roll Compression in.
Basis Weight Raw
−3.24
3.00
2.20
3.05
Wtg.
Sensory Softness
[0074] The graphs presented in FIGS. 10 to 22 represent the outcome of Example 2 compared directly to the current product.
[0075] 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.
|
A method of increasing the density and reducing the bulk of multi-ply paper products allowing one to reduce the roll size or increase the roll content, while minimizing the destruction of favorable product attributes.
| 3
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a semiconductor device, and more particularly to a semiconductor device including an input buffer that receives a signal from outside to transmit the signal to an internal circuit.
[0003] 2. Description of the Background Art
[0004] A semiconductor device includes an input buffer that receives a signal input from outside. A conventional input buffer is constructed with a differential amplification circuit of a current mirror load and an inverter.
[0005] [0005]FIG. 8 is a circuit diagram showing a construction of a conventional input buffer 200 .
[0006] Referring to FIG. 8, the input buffer 200 includes a differential amplification circuit 202 that is activated in accordance with a signal EN and compares a reference voltage VREF with an input signal IN, and an inverter 204 that receives and inverts an output of the differential amplification circuit 202 and outputs an output signal OUT.
[0007] The differential amplification circuit 202 includes an N-channel MOS transistor 206 whose gate receives the signal EN and whose source is connected to a ground node, and an N-channel MOS transistor 208 whose gate receives the reference voltage VREF and whose source is connected to the drain of the N-channel MOS transistor 206 .
[0008] The differential amplification circuit 202 further includes an N-channel MOS transistor 210 whose gate receives the input signal IN and whose source is connected to the drain of the N-channel MOS transistor 206 , and a P-channel MOS transistor 212 whose gate and drain are connected to the drain of the N-channel MOS transistor 208 and whose source is connected to a power supply voltage Vcc.
[0009] The differential amplification circuit 202 further includes a P-channel MOS transistor 214 whose gate is connected to the drain of the N-channel MOS transistor 208 and which is connected between the node to which the power supply voltage Vcc is given and the drain of the N-channel MOS transistor 210 , and a P-channel MOS transistor 216 whose gate receives the signal EN and which is connected between the power supply node and the drain of the N-channel MOS transistor 210 . An output signal A of the differential amplification circuit 202 is output from the drain of the N-channel MOS transistor 210 .
[0010] The inverter 204 includes a P-channel MOS transistor 218 and an N-channel MOS transistor 220 both of which receive a signal A at the gates thereof and which are connected in series between the power supply node and the ground node. An output signal OUT is output from the connection node of the P-channel MOS transistor 218 and the N-channel MOS transistor 220 .
[0011] When the signal EN is raised to a H-level, the N-channel MOS transistor 206 is brought into a conducted state while the P-channel MOS transistor 216 is brought into a non-conducted state. Then, the differential amplification circuit 202 is activated and, if the input signal IN is higher than the reference voltage VREF, the differential amplification circuit 202 outputs a L-level to the signal A, whereas if the input signal IN is lower than the reference voltage VREF, the differential amplification circuit 202 outputs a H-level as the signal A.
[0012] However, regarding the amplitude of the output signal of the differential amplification circuit, it is not always the case that the H-level is the power supply voltage Vcc and the L-level is the ground voltage. There are cases in which the H-level of the output signal is lower than the power supply voltage Vcc or the L-level is higher than the ground voltage.
[0013] [0013]FIG. 9 is a waveform diagram for explaining an error operation of the input buffer.
[0014] Referring to FIGS. 8 and 9, the input signal IN is repeatedly at a higher voltage or at a lower voltage than the reference voltage VREF and, in accordance therewith, the output signal A of the differential amplification circuit 202 alternately outputs the H-level and the L-level. However, since the L-level of the signal A is higher than a threshold voltage Vt of the inverter 204 , the signal A does not cross over the threshold voltage of the inverter. Then, the output signal OUT of the inverter is fixed at the L-level.
[0015] Such a phenomenon occurs, for example, when the reference voltage VREF is low and, in such a case, it is difficult to raise the output of the differential amplification circuit above the threshold voltage of the inverter, thereby causing an error operation in which the output of the inverter remains invariable.
[0016] The threshold voltage of the inverter may change depending on production variations and, if the threshold value of the inverter changes, there is a problem of decrease in the production yield.
SUMMARY OF THE INVENTION
[0017] An object of the present invention is to provide a semiconductor device including an input buffer that does not easily raise an error operation even under threshold voltage variations of the inverter caused by production variations.
[0018] In summary, the present invention is directed to a semiconductor device including an input buffer circuit and an internal circuit.
[0019] The input buffer circuit receives a first input signal from outside. The input buffer circuit includes first and second differential amplification circuits and an output circuit. The first differential amplification circuit compares a voltage given by the input signal with a reference voltage and outputs complementary first and second output signals in which a high level of an output voltage is a power supply voltage and a low level is a first intermediate voltage between the power supply voltage and a ground voltage. The second differential amplification circuit compares the voltage given by the first input signal with the reference voltage and outputs complementary third and fourth output signals in which a low level of an output voltage is the ground voltage and a high level is a second intermediate voltage between the power supply voltage and the ground voltage. The output circuit outputs complementary fifth and sixth output signals in accordance with the first to fourth output signals.
[0020] The internal circuit operates in accordance with the fifth and sixth output signals.
[0021] Therefore, a principal advantage of the present invention lies in that the error operation in which the input signal is not transmitted to the inside can be prevented when the threshold voltage variations occur due to process variations.
[0022] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] [0023]FIG. 1 is a block diagram illustrating a schematic construction of a synchronous semiconductor storage device 1 which is an example of a semiconductor device;
[0024] [0024]FIG. 2 is a circuit diagram illustrating a construction of a clock buffer 4 in FIG. 1;
[0025] [0025]FIG. 3 is an operation waveform diagram for explaining an operation of the clock buffer 4 shown in FIG. 2;
[0026] [0026]FIG. 4 is a circuit diagram illustrating a construction of a flip-flop 6 a which is included in a control signal input buffer 6 in FIG. 1 and which receives a control signal from outside and takes it in with an internal clock;
[0027] [0027]FIG. 5 is a circuit diagram illustrating a construction of an inside of an input buffer 22 in FIG. 1;
[0028] [0028]FIG. 6 is a view for explaining a part of an address buffer 2 in FIG. 1;
[0029] [0029]FIG. 7 is a circuit diagram illustrating a construction of a predecoding circuit 142 which is disposed near to a memory array and which predecodes an address;
[0030] [0030]FIG. 8 is a circuit diagram illustrating a construction of a conventional input buffer 200 ; and
[0031] [0031]FIG. 9 is a waveform diagram for explaining an error operation of the input buffer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Hereafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Here, like reference numerals in the drawings denote like or corresponding parts.
[0033] [0033]FIG. 1 is a block diagram illustrating a schematic construction of a synchronous semiconductor storage device 1 as an example of a semiconductor device.
[0034] Referring to FIG. 1, the synchronous semiconductor storage device 1 includes memory array banks 14 # 0 to 14 # 3 each having a plurality of memory cells that are arranged in a matrix configuration; an address buffer 2 that takes in address signals A 0 to A 12 and bank address signals BA 0 to BA 1 , which are given from the outside, in synchronization with clock signals CLKI, /CLKI and outputs an internal row address, an internal column address, and an internal bank address; a clock buffer 4 that receives a clock signal CLK and a clock enable signal CKE from the outside and outputs clock signals CLKI, /CLKI, and CLKQ used in the inside; and a control signal input buffer 6 that takes in control signals /CS, /RAS, /CAS, /WE, and a mask signal DQMU/L, which are given from the outside, in synchronization with the clock signals CLKI, /CLKI.
[0035] The synchronous semiconductor storage device 1 further includes a control circuit that receives an internal address signal from the address buffer 2 and receives control signals int.RAS, int.CAS, int.WE synchronized with the clock signals from the control signal input buffer 6 to output a control signal to each block in synchronization with the clock signals CLKI, /CLKI, and a mode register that holds the operation mode recognized in the control circuit. In FIG. 1, the control circuit and the mode register are represented by one block 8 .
[0036] The control circuit includes a bank address decoder that decodes internal bank address signals int.BA 0 , int.BA 1 , and a command decoder that receives and decodes the control signals int.RAS, int.CAS, int.WE.
[0037] The synchronous semiconductor storage device 1 further includes row decoders that are disposed respectively in correspondence with the memory array banks 14 # 0 to 14 # 3 and decode a row address signal X given from the address buffer 2 , and word drivers for driving an address-designated row (word line) in the inside of the memory array banks 14 # 0 to 14 # 3 to a selected state in accordance with the output signals of these row decoders. In FIG. 1, the row decoders and the word drivers are collectively represented by blocks 10 # 0 to 10 # 3 .
[0038] The synchronous semiconductor storage device 1 further includes column decoders 12 # 0 to 12 # 3 that decode an internal column address signal Y given from the address buffer 2 to generate a column selection signal, and sensing amplifiers 16 # 0 to 16 # 3 that sense and amplify data of the memory cells connected to the selected row of the memory array banks 14 # 0 to 14 # 3 .
[0039] The synchronous semiconductor storage device 1 further includes an input buffer 22 that receives a write data from the outside to generate an internal write data, a write driver that amplifies the internal write data from the input buffer 22 and transmits the internal write data to the selected memory cell, a preamplifier that amplifies the data read out from the selected memory cell, and an output buffer 20 that performs a buffer processing on the data from the preamplifier and outputs the data to the outside.
[0040] The preamplifier and the write driver are disposed respectively in correspondence with the memory array banks 14 # 0 to 14 # 3 . In FIG. 1, the preamplifier and the write driver are represented by blocks 18 # 0 to 18 # 3 as one block.
[0041] The input buffer 22 takes in the data signals DQ 0 to DQ 15 given from the outside to the terminal in accordance with a strobe signal DS. This strobe signal DS is a signal that constitutes a standard of the time for another semiconductor device or the like, which outputs data to the synchronous semiconductor storage device 1 , to take in the data that are output in synchronization with the data. The synchronous semiconductor storage device 1 receives the strobe signal DS, which is transmitted from the outside in parallel with the data and which is given to the terminal, as a standard for taking in the data signals.
[0042] The synchronous semiconductor storage device 1 further includes a Vref generating circuit 24 that generates a reference voltage Vref. The reference voltage Vref is input to the input buffer and constitutes a standard for a threshold value in taking in the data.
[0043] When the synchronous semiconductor storage device 1 outputs data to the outside, the output buffer 20 outputs the data signals DQ 0 to DQ 15 in synchronization with the clock signal CLKQ, and outputs to the outside the strobe signal DS for another semiconductor device to take in the data signals.
[0044] In such a synchronous semiconductor storage device 1 , the clock signal CLK given from the outside is given by being converted by the clock buffer 4 into the clock signals CLKI, /CLKI and CLKQ that are used in the inside. For example, the clock signal CLKQ is given to the input buffer 22 and the output buffer 20 ; however, the clock delay time till the clock signal CLKQ is transmitted to the input buffer 22 is preferably equal to the clock delay time till the clock signal CLKQ is transmitted to the output buffer 20 .
[0045] [0045]FIG. 2 is a circuit diagram illustrating a construction of the clock buffer 4 in FIG. 1.
[0046] Referring to FIG. 2, the clock buffer 4 includes a differential amplification circuit 32 that receives a reference voltage VREF and an input signal IN and outputs a differential output to a node NA and a node NC; P-channel MOS transistors 38 , 36 for fixing the voltages of the node NA and the node NC to the power supply voltage Vcc in accordance with a signal EN; a differential amplification circuit 34 that receives the reference voltage VREF and the input signal IN and outputs a differential output to a node NB and a node ND; N-channel MOS transistors 42 , 40 for fixing the voltages of the nodes NB, ND to the ground voltage in accordance with a signal /EN; and an output circuit 44 that outputs output signals OUT, /OUT in accordance with the voltages of the nodes NA, NB, NC, ND.
[0047] The differential amplification circuit 32 includes an N-channel MOS transistor 50 whose gate receives the signal EN and whose source is connected to the ground node, an N-channel MOS transistor 46 whose gate receives the reference voltage VREF and which is connected between the node NC and the drain of the N-channel MOS transistor 50 , and an N-channel MOS transistor 48 whose gate receives the input signal IN and which is connected between the node NA and the drain of the N-channel MOS transistor 50 .
[0048] The differential amplification circuit 32 further includes a P-channel MOS transistor 52 whose gate is connected to the node NC and which is connected between the power supply node and the node NC, a P-channel MOS transistor 54 whose gate is connected to the node NA and which is connected between the power supply node and the node NC, a P-channel MOS transistor 56 whose gate is connected to the node NC and which is connected between the power supply node and the node NA, and a P-channel MOS transistor 58 whose gate is connected to the node NA and which is connected between the power supply node and the node NA.
[0049] The P-channel MOS transistor 52 and the P-channel MOS transistor 56 form a first current mirror, and the P-channel MOS transistor 58 and the P-channel MOS transistor 54 form a second current mirror. In other words, the differential amplification circuit 32 uses a current mirror of cross-coupling type as a load of differential amplification.
[0050] The differential amplification circuit 34 includes a P-channel MOS transistor 62 whose source is connected to the power supply node and whose gate receives the signal /EN, a P-channel MOS transistor 64 whose gate receives the reference voltage VREF and which is connected between the drain of the P-channel MOS transistor 62 and the node ND, a P-channel MOS transistor 66 whose gate receives the input signal IN and which is connected between the drain of the P-channel MOS transistor 62 and the node NB, an N-channel MOS transistor 68 whose gate and drain are connected to the node ND and whose source is connected to the ground node, an N-channel MOS transistor 70 whose gate is connected to the node NB and which is connected between the node ND and the ground node, an N-channel MOS transistor 72 whose gate is connected to the node ND and which is connected between the node NB and the ground node, and an N-channel MOS transistor 74 whose gate is connected to the node NB and which is connected between the node NB and the ground node.
[0051] The output circuit 44 includes a P-channel MOS transistor 76 and an N-channel MOS transistor 78 which are connected in series between the power supply node and the ground node and whose gates are respectively connected to the nodes NA, NB, and a P-channel MOS transistor 80 and an N-channel MOS transistor 82 which are connected in series between the power supply node and the ground node and whose gates are respectively connected to the nodes NC, ND. A signal OUT is output from the connection node of the P-channel MOS transistor 76 and the N-channel MOS transistor 78 , and a signal /OUT is output from the connection node of the P-channel MOS transistor 80 and the N-channel MOS transistor 82 .
[0052] [0052]FIG. 3 is an operation waveform diagram for explaining the operation of the clock buffer 4 shown in FIG. 2.
[0053] When the voltage of the input signal IN becomes higher than the reference voltage VREF at the time t 1 , the voltages of the node NA and the node NB come to an L-level. At this time, with respect to the output of the differential amplification circuit 32 of a differential type driven by N-channel MOS transistors, the output amplitude is biased to the vicinity of the power supply voltage Vcc, as shown by the voltage of the node NA.
[0054] On the other hand, with respect to the differential amplification circuit 34 of a differential type driven by P-channel MOS transistors, the output amplitude is biased to the vicinity of the ground voltage, as shown by the voltage of the node NB. Therefore, since the voltage of the node NB is at the ground voltage at the time t 1 to t 2 , the N-channel MOS transistor 78 of the output stage can be cut off by inputting this voltage to the N-channel MOS transistor 78 .
[0055] Subsequently, when the voltage of the input signal IN becomes lower than the reference voltage VREF at the time t 2 , the voltages of the nodes NA, NB come to a H-level in accordance therewith. In this case, since the voltage of the node NA is equal to the power supply voltage Vcc, the P-channel MOS transistor 76 can be cut off by giving this voltage to the gate of the P-channel MOS transistor 76 . Therefore, the input signal can be correctly transmitted to the output signal OUT.
[0056] Further, since the differential amplification circuits 32 , 34 have respective complementary output signals, a complementary output signal /OUT can be created by giving a signal to the gates of the P-channel MOS transistor 80 and the N-channel MOS transistor 82 . With the use of a clock buffer circuit having a construction described above, the output signals OUT, /OUT can be correctly output even if the threshold value of the inverter is varied due to production variations, so that the clock signals CLKI, /CLKI can be correctly generated.
[0057] Here, in this embodiment, an example is shown in which the input buffer circuit shown in FIG. 2 is used as a clock buffer; however, the usage is not limited to clock buffers alone, and it can be used as another input buffer that receives an input signal from outside.
[0058] Next, explanation will be given on an advantage of the case in which a buffer circuit having such complementary outputs is used.
[0059] [0059]FIG. 4 is a circuit diagram illustrating a construction of a flip-flop 6 a which is included in the control signal input buffer 6 in FIG. 1 and which receives a control signal from outside and takes it in with an internal clock.
[0060] Referring to FIG. 4, the flip-flop 6 a includes an inverter 92 that receives and inverts an input signal A, an N-channel MOS transistor 94 that transmits an output of the inverter 92 when the clock signal CLKI is at a H-level, an inverter 96 that inverts the output of the inverter 92 transmitted by the N-channel MOS transistor 94 , an inverter 98 that feeds an output of the inverter 96 back to an input part of the inverter 96 , an inverter 100 that receives and inverts the output of the inverter 96 , an N-channel MOS transistor 102 that is conducted in accordance with a clock signal /CLKI and transmits an output of the inverter 100 , an inverter 104 that receives and inverts the output of the inverter 100 transmitted by the N-channel MOS transistor 102 and outputs a signal B, and an inverter 106 that feeds an output of the inverter 104 back to an input of the inverter 104 .
[0061] By supplying complementary clocks with the use of a clock buffer such as shown in FIG. 2, the flip-flop 6 a need not incorporate a phase splitter that generates complementary internal clocks from the clock signal. In other words, in many cases, a flip-flop usually incorporates a phase splitter such as an inverter that inverts the clock signal. Therefore, by omitting the inverter, the circuit construction can be simplified.
[0062] [0062]FIG. 5 is a circuit diagram illustrating a construction of an inside of the input buffer 22 shown in FIG. 1.
[0063] Referring to FIG. 5, the input buffer 22 includes an input buffer circuit 112 that receives the data strobe signal DS and outputs the signals IDS, /IDS, and a latch circuit 114 that takes in the data signal DQ in accordance with the signals IDS, /IDS and outputs an even data signal DATAE and an odd data signal DATAO.
[0064] The input buffer circuit 112 has a construction similar to that of the clock buffer 4 shown in FIG. 2, so that an explanation thereof will not be repeated.
[0065] The latch circuit 114 includes an N-channel MOS transistor 116 that is conducted in accordance with the signal /IDS and transmits the data signal DQ, an inverter 118 that receives and inverts the signal transmitted by the N-channel MOS transistor 116 and outputs the even data signal DATAE, and an inverter 120 that receives the output of the inverter 118 and feeds the output to an input of the inverter 118 .
[0066] The latch circuit 114 further includes an N-channel MOS transistor 122 that transmits the data signal DQ in accordance with the signal IDS, an inverter 124 that receives and inverts the data signal DQ transmitted by the N-channel MOS transistor 122 and outputs the odd data signal DATAO, and an inverter 126 that receives the output of the inverter 124 and feeds the output to an input of the inverter 124 .
[0067] By adopting such a construction, complementary latch signals are supplied to the latch circuit 114 , thereby eliminating the need for incorporating a phase splitter in the inside. This can simplify the circuit construction.
[0068] [0068]FIG. 6 is a view for explaining a part of the address buffer 2 shown in FIG. 1.
[0069] Referring to FIG. 6, the address buffer 2 includes an input buffer circuit 132 that receives address signals A 0 to A 2 and outputs complementary signals AD 0 to AD 2 , /AD 0 to /AD 2 . Here, the input buffer circuit 132 includes an input buffer having a construction similar to that of the clock buffer 4 shown in FIG. 2 and corresponding to each of the address signals A 0 to A 2 , so that an explanation thereof will not be repeated.
[0070] [0070]FIG. 7 is a circuit diagram illustrating a construction of a predecoding circuit 142 which is disposed near to the memory array and which predecodes an address.
[0071] Referring to FIG. 7, the predecoding circuit 142 includes a NAND circuit 144 that receives signals /AD 0 , /AD 1 , /AD 2 , an N-channel MOS transistor 146 that is conducted in accordance with the clock signal CLKI and transmits an output of the NAND circuit 144 , an inverter 148 that receives and inverts the output of the NAND circuit 144 transmitted by the N-channel MOS transistor 146 and outputs a predecoded signal AX 0 , and an inverter 150 that receives and inverts an output of the inverter 148 and feeds the output to an input of the inverter 148 .
[0072] The predecoding circuit 142 further includes a NAND circuit 154 that receives signals /AD 0 , /AD 1 , /AD 2 , an N-channel MOS transistor 156 that is conducted in accordance with the clock signal CLKI and transmits an output of the NAND circuit 154 , an inverter 158 that receives and inverts the output of the NAND circuit 154 transmitted by the N-channel MOS transistor 156 and outputs a predecoded signal AX 1 , and an inverter 160 that receives and inverts an output of the inverter 158 and feeds the output to an input of the inverter 158 .
[0073] The predecoding circuit 142 further includes a NAND circuit 164 that receives signals AD 0 , AD 1 , AD 2 , an N-channel MOS transistor 166 that is conducted in accordance with the clock signal CLKI and transmits an output of the NAND circuit 164 , an inverter 168 that receives and inverts the output of the NAND circuit 164 transmitted by the N-channel MOS transistor 166 and outputs a predecoded signal AX 7 , and an inverter 170 that receives and inverts an output of the inverter 168 and feeds the output to an input of the inverter 168 .
[0074] Here, although not illustrated, the predecoding circuit 142 further includes circuits that output predecoded signals AX 2 to AX 6 in accordance with the output of the input buffer circuit 132 .
[0075] As described above, by inputting an address signal with the use of a construction such as shown in FIGS. 6 and 7, the address can be predecoded at a high speed before it is latched with the clock signal, thereby raising a speed of the address signal processing.
[0076] Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
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An output circuit is driven by means of a first differential amplification circuit having an N-channel differential amplification stage that compares a reference voltage VREF with an input signal IN, and a second differential amplification circuit having a P-channel differential stage. An output of the first differential amplification circuit is given as the gate voltage of P-channel MOS transistors in the output circuit, and an output of the second differential amplification circuit is given as the gate voltage of N-channel MOS transistors in the output circuit. This realizes an input buffer with reduced error operations even under threshold voltage variations caused by process variations and others.
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BACKGROUND OF THE INVENTION
All types of electrical connectors are attached to ends of wires by crimping a suitable portion of the connector; e.g., a wire barrel around the wire with sufficient force to permanently join the connector and wire. Rapid semi- or fully automatic crimping operations require the use of power actuated presses. Such presses in turn require suitable safety guards to prevent injury to the operators. One type of guard involved was placing plastic guards across the front with a hole therethrough. The operator had to place the connector on the end of the wire, pass that loose assembly through the hole and remotely guide it onto the press anvil. Then, while still holding onto the length of cable the operator hit the foot button to operate the press. Obviously this method resulted in very slow application rates and in addition, many connectors would be improperly crimped due to being shifted slightly by the operator due to fatigue, disinterest and so forth. The solution to this problem basically required the means which would result in removing the plastic guards, having the operator place the loose assembly directly onto the anvil, securely holding the assembly mechanically and then requiring the use of both hands at a remote station to energize the press.
Accordingly the present invention provides a crimping press which includes a lever arm which locates and securely holds the loose assembly on the press anvil and which further requires the operator to push two widely spaced buttons simultaneously to actuate the press.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the crimping press incorporating the present invention;
FIG. 2 is an elevation, partially cross-sectioned view of the present invention;
FIG. 3 is a perspective view of the crimping press of FIG. 1 fully loaded with a connector; and
FIG. 4 is a perspective view of the crimping press of FIG. 1 and the dual buttons required for the press operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Crimping press 10, appearing in FIGS. 1 and 3-5 embody many elements found in conventional presses. the crimping die anvil assembly 12 rests on a pedestal-base 14 which may be bolted to the press frame (FIG. 5). The crimping die nest assembly 16 is removably mounted on the bottom of a reciprocating ram 18. As is well known in the art, crimping of a connector about a wire occurs by advancing ram 18 toward the base 14 whereby the anvil assembly 12 and nest assembly 16 squeeze the appropriate portions of the connector between them to affect the crimp. Whereas presses such as crimping press 10 crimp many types of connectors onto many types of wires and cables, crimping press 10 has been developed to crimp UHF connectors about coaxial cable. Thus the following description will be concerned about such connectors. However, it is to be understood that the invention can be applied to most any type of crimping press.
With specific reference to FIG. 1, the anvil assembly 12 includes a front plate 20 behind which is center pin anvil 22 of the center pin crimping die. A notch 24 having two sides at right angles to each other occupy generally the center of the upper edge of a vertical wall 26. A shelf 28 extends rearwardly from the base of the wall. A spring biased lever arm 30, positioned over the shelf 28, extends laterally from a spring housing 32 located to one side of the center pin anvil and behind plate 20. The arm is pivotably mounted to the spring housing by pin 34. The lower edge of the lever arm contains a rounded indent 36.
A recess 38 separates center pin anvil 22 from ferrule anvil 40 of the ferrule crimping die. The ferrule anvil has on its upper surface a three-sided notch 42 with an arcuate relief 44 immediately in front.
The insulation anvil 46 is located behind ferrule anvil 40, separated therefrom by a gap 48. A three-sided notch 50 crosses the upper surface of the insulation anvil.
The three notches 24, 42 and 50 are concentric but lie at different elevations with respect to the base so as to accommodate the various portions of the UHF connector as will be seen below.
The nest assembly 16 contains the center pin nest 52, a recess 54, ferrule nest 56 and insulation nest 58. Generally the nests reflect the same structure as the anvils 22, 40 and 46 and also contain identical notches 24, 42 and 50. Two exceptions are (1) there is no shelf on the center pin nest 52 and (2) no lever arm 30 and its accouterments. The absence of the shelf provides space for the lever arm as the nest assembly 16 is brought down onto the anvil assembly 12.
FIG. 2 shows the details to the lever arm 30. The view shown is looking at this unit from the back of the press and is sectioned, such sectioning being normal to the longitudinal axis of the anvil assembly 12.
Using the pivot pin 34 as the dividing point, lever arm 30 can be described as having a handle section 60 to the left of the pin and a biased section 62 to the right. The biased section is contained within a slot 64 which bisects housing 32 and which deepens towards its right side.
A deep aperture 66 is provided in the housing and therein resides coil spring 68. As the drawing shows, the spring bears against the bottom edge of the biased section 62 of the lever arm. A pin 70, anchored in the housing 32 and crossing the aperture 66 and over the biased section through notch 72, limits the angular movement of the arm in one direction. The bottom of slot 64 limits the movement in the other direction.
The handle section 60 of the lever arm 30 has an upwardly angled free end 74 to facilitate sliding a UHF connector inbetween the arm and the center pin anvil 22.
FIG. 3 shows the press 10 of FIG. 1 with the addition of a UHF connector 76 positioned in the anvil assembly 12. A coaxial cable 78 has been loosely fitted into connector 76 preparatory to the crimping operation. The connector components include the coupling nut 80, shell member and dielectric unit 82, center pin 84 and ferrule member 86. The ferrule member includes a braided shield section 88 and insulating section 90. The forward end of center pin 84 lies in notch 24 in anvil 22, the ferrule's braided section 88 lies in notch 42 in anvil 40 and the ferrule's insulating section 90 lies in notch 50 in anvil 46. The coupling nut 80 occupies recess 38. Under the biasing of coil spring 68, handle section 60 of lever arm 30 bears down against the center pin which is lodged in indent 36. Clearly the UHF connector 76 is securely restrained between the lever arm and the three notches on the anvil assembly.
FIG. 4 illustrates the crimping press 10 provided with dual electrical push buttons 92 and 94. Both buttons need to be pushed simultaneously to actuate press 10. Clearly, the spaced buttons means that the operator must use both hands to depress the buttons together. With the addition of lever arm 30, the use of such buttons is feasible.
In actual use of the press employing the present invention, a thirty percent increase in application rates were achieved. Further, misalignments have been eliminated. Obviously crimping press 10 reduces the cost of a terminated coaxial cable.
The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitation should be understood therefrom, as some modifications will be obvious to those skilled in the art.
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This invention relates to a press useful for terminating or crimping an electrical connector to a cable. More particularly the press includes die members which crimp the connector about the cable. The press further contains a lever arm adapted to securely hold the connector in crimping position so that conventional guards normally employed with crimping presses are not now necessary.
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PRIORITY CLAIM
[0001] This application claims the benefit of Provisional U.S. Patent Application No. 60/304,244, filed Jul. 10, 2001, entitled “Electrostatic Discharge Suppression Termination Resistor” and having an attorney docket No. 112690-192.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to termination resistors. More particularly, the present invention relates to an improved voltage variable material (“VVM”) that is employed additionally as a termination resistor.
[0003] Electrical overstress transients (“EOS transients”) produce high electric fields and high peak powers that can render circuits, or the highly sensitive electrical components in the circuits, temporarily or permanently non-functional. EOS transients can include transient voltages or current conditions capable of interrupting circuit operation or destroying the circuit outright. EOS transients may arise, for example, from an electromagnetic pulse, an electrostatic discharge, e.g., from a device or a human body, lightning, a build up of static electricity or be induced by the operation of other electronic or electrical components. An EOS transient can rise to its maximum amplitude in subnanosecond to microsecond times and have repeating amplitude peaks.
[0004] The peak amplitude of the electrostatic discharge (“ESD”) transient wave may exceed 25,000 volts with currents of more than 100 amperes. There exist several standards which define the waveform of the EOS transient. These include IEC 61000-4-2, ANSI guidelines on ESD (ANSI C63.16), DO-160, and FAA-20-136. There also exist military standards, such as MIL STD 883 part 3015.
[0005] Materials exist for the protection against EOS transients (“EOS materials”), which are designed to rapidly respond (i.e., ideally before the transient wave reaches its peak) to reduce the transmitted voltage to a much lower value and clamp the voltage at the lower value for the duration of the EOS transient. EOS materials are characterized by having high electrical impedance values at low or normal operating voltages. In response to an EOS transient, the materials switch essentially instantaneously to a low electrical impedance state. When the EOS threat has been mitigated these materials return to their high impedance state. These materials are capable of repeated switching between the high and low impedance states, allowing circuit protection against multiple EOS events.
[0006] EOS materials also recover essentially instantaneously to their original high impedance value upon termination of the EOS transient. EOS materials can switch to the low impedance state thousands of times, withstanding thousands of ESD events, and recover to the high impedance state after providing protection from each of the individual ESD events.
[0007] Circuit components utilizing EOS materials can shunt a portion of the excessive voltage or current due to the EOS transient to ground, protecting the electrical circuit and its components. The major portion of the threat transient, however, is reflected back towards the source of the threat. The reflected wave is either attenuated by the source, radiated away, or re-directed back to the surge protection device which responds to each return pulse until the threat energy is reduced to safe levels.
[0008] One voltage variable material or composition for providing protection against electrical overstress is disclosed in U.S. Pat. No. 6,251,513 B1, entitled, “Polymer Composites for Overvoltage Protection”, assigned to the assignee of this invention, the teachings of which are incorporated herein by reference. Other voltage variable materials, the teachings of which are incorporated herein by reference, include the following.
[0009] U.S. Pat. No. 2,273,704, issued to Grisdale, discloses granular composites which exhibit non-linear current/voltage relationships. These mixtures are comprised of conductive and semiconductive granules that are coated with a thin insulative layer and are compressed and bonded together to provide a coherent body.
[0010] U.S. Pat. No. 2,796,505, issued to Bocciarelli, discloses a non-linear voltage regulating element. The element is comprised of conductor particles having insulative oxide surface coatings that are bound in a matrix. The particles are irregular in shape and make point contact with one another.
[0011] U.S. Pat. No. 4,726,991 issued to Hyatt et al., discloses an EOS protection material comprised of a mixture of conductive and semiconductive particles, all of whose surfaces are coated with an insulative oxide film. These particles are bound together in an insulative binder. The coated particles are preferably in point contact with each other and conduct preferentially in a quantum mechanical tunneling mode.
[0012] U.S. Pat. No. 5,476,714, issued to Hyatt, discloses EOS composite materials comprised of mixtures of conductive and semiconductive particles sized to be in a 10 to 100 micron range. The materials also include a proportion of insulative particles. All of these materials are bonded together in an insulative binder. This invention includes a grading of particle sizes such that the composition causes the particles to take a preferential relationship to each other.
[0013] U.S. Pat. No. 5,260,848, issued to Childers, discloses foldback switching materials which provide protection from transient overvoltages. These materials are comprised of mixtures of conductive particles in the 10 to 200 micron range. Semiconductor and insulative particles are also employed in these compositions. The spacing between conductive particles is at least 1000 angstroms.
[0014] Additional EOS polymer composite materials are also disclosed in U.S. Pat. Nos. 4,331,948, 4,726,991, 4,977,357, 4,992,333, 5,142,263, 5,189,387, 5,294,374, 5,476,714, 5,669,381 and 5,781,395, the teachings of which are specifically incorporated herein by reference.
[0015] Data communication circuits often require the use of resistors to perform termination, impedance matching, pull-up or pull-down functions. These techniques are well known and are applied in a wide variety of serial and parallel data bus architectures. These resistors commonly take the form of discrete components or arrays of multiple resistors which may be mounted to a printed circuit board (“PCB”), wherein the PCB also holds data transmission receiver and transmitter circuitry. It is this circuitry that is often the most vulnerable to the damaging effects of ESD, since it is connected to the outside environment by a bus or metallic conductors that are used for data transmission.
[0016] A common technique to protect the circuitry against ESD damage is the use of discrete ESD suppressors or arrays of multiple suppressors mounted on the PCB. The suppressors are electrically connected from the data lines to system ground or a voltage supply line. In many cases, the suppressors can be connected in parallel with the aforementioned resistors since they are themselves connected between the data lines and system ground or the voltage supply line.
[0017] One problem with connecting the suppressors in parallel with the resistors is that the resistors and suppressors consume valuable space on the PCB, which adds to system size and cost. Another problem involves the circuit board traces that interconnect termination resistors, suppressors, data lines, and system ground or supply lines. At high frequency and data rates, these traces can introduce parasitic impedance effects, which can degrade suppressor effectiveness and data signal integrity.
[0018] As mentioned earlier, the techniques associated with data line resistors are practiced in spite of the size, cost and interconnection problems. This is due to the essential nature of impedance matching, termination, and logic level pull-up and pull-down functionality in various data transmission schemes.
[0019] It would be desirable to have an apparatus and method to combine the transient suppression capability of an EOS or VVM material with the functionality of a data line resistor. This would enable one device or apparatus to perform multiple functions, reduce size and cost of the PCB and enhance performance. The range of resistances required to perform the described data line functions is generally in the range of 50 to 100,000 ohms. Until now, the high impedance of the normal state for known VVM's has been too great by orders of magnitude for this application.
SUMMARY OF THE INVENTION
[0020] The present invention provides an improved electrical overstress (“EOS”) or voltage variable material (“VVM”). More specifically, the present invention provides a polymer VVM that has been formulated with a high percentage loading of conductive and/or semiconductive particles. The conductivity of this VVM is in the range of 10 to 100 ohms per a selected application area. The exact resistance for an application of this material is therefore determined by the area of material applied. A known length and width of the material is placed between adjacent electrodes to produce a desired resistance. One application for this “resistor” is the termination of a transmission line to prevent unwanted reflections and distortion of high frequency signals. In an embodiment, the transmission line is a printed circuit board trace. This resistor behaves according to Ohm's Law at normal circuit voltages, but has the ability to switch to a drastically lower resistance when exposed to an ESD transient or event.
[0021] To this end, in one embodiment of the present invention, a resistor providing protection against an electrical overstress event is provided. The resistor includes an insulating binder. Conductive particles having a volume percentage range of 20 to 72% are mixed with the insulating binder. A quantity of the conductive particles and the binder is then deposited in a specific geometric size to achieve a desired resistance.
[0022] In an embodiment, the conductive particles include a material selected from the group consisting of: nickel, carbon black, aluminum, silver, gold, copper and graphite, zinc, iron, stainless steel, tin, brass, and alloys thereof, and conducting organic materials, such as intrinsically conducting polymers.
[0023] In an embodiment, the conductive particles have a bulk conductivity greater than 1×10 (ohm-cm) −1 .
[0024] In an embodiment, the insulating binder includes a material selected from the group consisting of: thermoset polymers, thermoplastic polymers, elastomers, rubbers and polymer blends.
[0025] In an embodiment, the insulating binder includes a silicone resin.
[0026] In an embodiment, semiconductive particles are mixed with the binder and the conductive particles.
[0027] In an embodiment, the semi-conductive particles include silicon carbide.
[0028] In an embodiment, the semi-conductive particles have a bulk conductivity in a range of 10 to 1×10 −6 (ohm-cm) −1 .
[0029] In an embodiment, insulating particles are mixed with the binder and the conductive particles.
[0030] In an embodiment, the binder and the conductive particles are enclosed in a discrete housing.
[0031] In an embodiment, the housing is surface mountable to a printed circuit board.
[0032] In an embodiment, the resistor is a pull-up/pull-down resistor.
[0033] In another embodiment of the present invention, a data line resistor and electrical overstress (“EOS”) protection device for a transmission line is provided. The device includes a pair of electrodes. A resistor composed of a voltage variable material (“VVM”) electrically couples to the electrodes. The voltage variable material of the resistor is applied in a quantity that provides a desired resistance.
[0034] In an embodiment, the voltage variable material includes an insulating binder and conductive particles mixed with the insulating binder, the particles having a volume percentage range of 20 to 72%.
[0035] In an embodiment, the semiconductive particles mixed with the binder and the conductive particles are enclosed in a housing.
[0036] In an embodiment, the housing is surface mountable to a printed circuit board.
[0037] In an embodiment, the VVM resistor electrically communicates with a ground contact.
[0038] In an embodiment, the data line resistor and EOS protection device includes a capacitor that electrically communicates with the VVM resistor and a ground contact.
[0039] In an embodiment, the data line resistor and EOS protection device includes a plurality of VVM resistors that each electrically communicate with a separate pair of electrodes. In an embodiment, one electrode of each pair of electrodes couples to a unique transmission line.
[0040] In an embodiment, the data line resistor and EOS protection device includes at least one capacitor that electrically communicates with the VVM resistors.
[0041] In an embodiment, the data line resistor and EOS protection device includes a plurality of VVM resistors that electrically communicate with a plurality of ground contacts.
[0042] In an embodiment, the binder mixed with the conductive particles is enclosed in a housing.
[0043] In an embodiment, the housing is surface mountable to a printed circuit board located inside the connector.
[0044] In yet another embodiment of the present invention, a resistor providing protection against an electrical overstress is provided. The resistor includes a printed circuit board (“PCB”). A pair of pads are etched onto the PCB. A resistor electrically connects to the pads. A quantity of voltage variable material is applied to electrical connections between the resistor and the pads.
[0045] It is therefore an advantage of the present invention to provide a VVM material as a resistor.
[0046] Another advantage of the present invention is to provide a VVM material as a termination device for data transmission lines.
[0047] A further advantage of the present invention is to provide a VVM material as a “pull up” or “pull down” resistor in a data or signal line.
[0048] Yet another advantage of the present invention is to provide a VVM resistor that can be directly applied to a printed circuit board or other type of circuit substrate.
[0049] Yet a further advantage of the present invention is to provide a VVM resistor in a surface mountable device.
[0050] Moreover, it is an advantage of the present invention to provide a multiple function electrical device that takes up less PCB space.
[0051] Additionally, it is an advantage of the present invention to provide a multiple function electrical device that improves system performance.
[0052] Additional features and advantages of the present invention will be described in, and apparent from, the following Detailed Description of the Preferred Embodiments and the Drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0053] [0053]FIG. 1A through 1C are schematic electrical diagrams of data network circuits employing known termination resistor techniques.
[0054] [0054]FIG. 2 is a schematic illustration of one embodiment of the voltage variable resistor of the present invention.
[0055] [0055]FIG. 3 is a circuit diagram illustrating a VVM resistor in a pull-up resistor application.
[0056] [0056]FIG. 4 is an alternative circuit diagram illustrating a VVM resistor in a pull-up resistor application.
[0057] [0057]FIG. 5 is a percolation curve of normalized normal state resistivity versus conductive filler concentration for a typical EOS material.
[0058] [0058]FIGS. 6A through 6C illustrate an alternative VVM resistor of the present invention, which employs a VVM material having a high resistivity in its normal state.
DETAILED DESCRIPTION OF THE INVENTION
[0059] Referring now to the drawings and in particular to FIGS. 1A through 1C, schematic diagrams of three commonly used data transmission termination techniques and employing a voltage variable material (“VVM”) resistor 12 (symbol illustrated is a combination of the resistor symbol plus a circuit protection device symbol) of the present invention are illustrated. In FIG. 1A, a data network circuit 10 includes a driver 20 , which can be a variety of known digital data driver integrated circuits. The circuit 10 also includes a load 16 , which is any type of data input circuit.
[0060] Transmission lines 18 that couple the driver 20 to the load 16 may each consist of a single conductor referenced to ground, differential pairs, or multiple single conductors each referenced to ground. The conductors are conductive, i.e., are metallic and in an embodiment are configured as circuit board traces. Alternatively, transmission lines 18 are single or multiple conductor cables, twisted pair cables, coaxial cables or any combination thereof.
[0061] As shown in the circuit 10 of FIG. 1A, a single VVM resistor 12 is applied to each data transmission line 18 . The nominal resistance of the VVM resistor 12 is normally chosen to match the characteristic impedance of the respective transmission line 18 to minimize signal reflection due to an impedance mismatch. During an ESD event, the VVM resistors 12 switch to low resistance values and provide high conductance paths to respective circuit grounds 22 . After the ESD event, the VVM resistors 12 return to their nominal resistance values. It should be appreciated that the VVM resistors 12 of the circuit 10 perform multiple functions, i.e., impedance matching and providing ESD protection.
[0062] [0062]FIG. 1B shows a circuit 30 employing the VVM resistor 12 in series combination with a capacitor 14 to form an AC termination network. Typically, the nominal resistance of the VVM resistor 12 is equal to the characteristic impedance of its respective data transmission line 18 . The methodology of selecting a capacitance value for the capacitor 14 is known to those of skill in the art, and as is chosen to minimize waveform distortion and power consumption. During an ESD event, the VVM resistors 12 of the circuit 30 switch to a low impedance state. In this state, the series combination of each resistor 12 and capacitor 14 constitutes a highly conductive path to ground during the fast rise, short duration ESD event. Again, the VVM resistors 12 of the circuit 30 perform the dual functions of impedance matching and providing circuit protection.
[0063] [0063]FIG. 1C shows a circuit 40 employing the VVM resistors 12 in a common Thevenin, or dual termination scheme, which requires two resistors for each line. The parallel combination of the resistors matches the characteristic impedance of the respective data transmission line 18 . The advantages of Thevenin termination is that the resistors also serve as pull-up and pull-down resistors. It should be noted that Vcc 42 , the system voltage supply line, is in effect at system ground potential for high frequency signals and fast rise, short duration ESD events. Therefore, in one embodiment employing Thevenin termination, both resistors are VVM resistors 12 , wherein two paths to ground exist (one to circuit ground 22 and one to Vcc 42 ) for the ESD energy. Alternatively, one of the two resistors is a conventional resistor with a fixed resistance, while the other resistor is the VVM resistor 12 , in which case there is one preferred path to ground for ESD energy. In this latter embodiment, the fixed resistor (not illustrated) is preferably connected between the transmission line 18 and Vcc 42 , while the VVM resistor 12 is connected between the transmission line 18 and ground 22 .
[0064] Referring now to FIG. 2, one embodiment of the VVM resistor 12 of the present invention is illustrated. Once the desired nominal resistance is known, the length and width of the application area for the VVM resistor 12 can be determined. The VVM of the present invention has a known and desired resistivity as described in more detail below. The desired nominal resistance is the resistance that will match the impedance of the transmission scheme. The desired nominal resistance divided by the resistivity of the VVM provides the necessary length of application, i.e., the distance of the gap G between electrodes 50 and 52 . The resistor 12 can therefore be provided in different sizes to cover different sized gaps depending on the characteristic impedance value of the data transmission scheme.
[0065] The present invention contemplates: (i) directly coupling the VVM resistor 12 by laying and trimming, if necessary a layer of VVM having a known resistivity across the gap “G” between electrodes 50 and 52 on a PCB, polyimide, polymer, flex circuit, any combination of these or other type of substrate or (ii) packaging the VVM material in a housing. One apparatus and method for directly coupling the VVM resistor 12 to the substrate is set forth in U.S. Provisional Patent application No. 60/370,975, entitled “Voltage Variable Material for Direct Application and Devices Employing Same”, assigned to the assignee of the present invention. This VVM intrinsically adheres to surfaces, such as a conductive, metal surface or a non-conductive, insulative surface or substrate, and cures without additional processing. Devices employing this VVM can be cured however to speed the manufacturing process of same. The binder disclosed in the provisional application can be used in combination with the VVM formulation set forth below to produce a directly applying, self-curable VVM resistance material for the resistor 12 . The resistance material does not require a device housing but can otherwise have a protective encapsulant, such as an epoxy.
[0066] The self-curing and self-adhering insulative binder of the VVM disclosed in Provisional Patent application No. 60/370,975 includes a polymer or thermoplastic resin, such as polyester, which is dissolved in a solvent. The polyester resin has a glass transition temperature in the range of 6° C. to 8° C. and a molecular weight between 15,000 and 23,000 atomic mass units (“AMU's”). One suitable solvent for dissolving the polymer is diethylene glycol monoethyl ether acetate, commonly referred to as “carbitol acetatate”. In an embodiment, a thickening agent is added to the insulative binder, which increases the viscosity of the insulative binder. For example, the thickening agent can be a fumed silica, such as that found under the tradename Cab-o-Sil TS-720.
[0067] The insulative binder of the present invention has a high dielectric breakdown strength, a high electrical resistivity and high tracking impedance. The insulative binder provides and maintains sufficient interparticle spacing between the other possible components of VVM 100 , such as conductive particles, insulating particles, semiconductive particles, doped semiconductive particles and various combinations of these. The interparticle spacing, the resistivity and dielectric strength of the insulative binder each affect the high impedance quality of the VVM in its normal state. In an embodiment, the insulative binder has a volume resistivity of at least 10 9 ohm-cm. It is possible to blend different polymers in the binder and to cross-link same.
[0068] Likewise, one device or housing for enclosing a quantity of VVM material is disclosed in U.S. Pat. No. 6,191,928 B1, entitled Surface-Mountable Device for Protection Against Electrostatic Damage to Electronic Components, assigned to the assignee of this invention, the teachings of which are incorporated herein by reference. The referenced patent involves a VVM having a very high normal impedance, which is not applied in a specific quantity to provide a desired Ohmic resistance. The housing of the present invention may have different sizes to house different sized quantities of VVM so as to provide a desired resistance, e.g., between 50-100,000 ohms.
[0069] Referring now to the high impedance gate 100 of FIG. 3, as described above another application of the present invention is to employ the VVM resistor 12 of the present invention as a pull-up or pull-down resistor. Pull-up resistors are well known in the art and are normally used to insure that given no other input, a circuit assumes a default value, such as the system supply voltage or Vcc 108 . That is, pull-up circuits prevent input lines from floating. The VVM resistor in the circuit 100 prevents too much current from flowing through the circuit. The resistor 12 may be employed as either a pull-up resistor or a pull-down resistor. Their function is the same, to create a default value for a circuit, but one pulls a line high, the other pulls it low, usually to system ground.
[0070] In FIG. 3, high impedance gate 100 has an input 102 and an output 104 . The high impedance input state of gate 100 means it provides no real power of its own. If nothing is connected to input 102 , the value of the input is considered to be floating (most gates will float towards a high state), wherein any electrical noise could cause input 102 to switch (e.g., go low). When a switch 106 is closed (on), the input state at input 102 is stable, since there is a definite connection to an electrical potential. When switch 106 open (off), input 102 is susceptible to a wide array of electrical problems if the VVM resistor 12 in the pull-up arrangement to Vcc 108 (+5 volts) does not exist. The traces or wires connected to input 102 may allow enough electrical noise in (by acting as little antennas) to cause device 124 to incorrectly switch states.
[0071] The pull-up VVM resistor 12 enables the input 102 to keep a steady state by connecting to an electrical potential, i.e., Vcc 108 , when switch 106 is open. Since input 102 is a high impedance input, it shows Vcc (+5v) when switch 106 is open. When switch 106 is closed (on), input 102 has a direct connection to ground 110 . The input 102 side of VVM resistor 12 also has a direct connection to ground when the switch 106 is closed, so that current flows from Vcc 108 , through resistor 12 , to ground. Resistor 12 is sized appropriately, e.g., 100 to 100,000 ohms, to limit the amount of current and prevent a short circuit.
[0072] The well known (but less used) alternative pull-down resistor (not illustrated) essentially involves reversing the relative positions of the VVM resistor 12 and the switch 106 as they are illustrated in FIG. 3. Just like the pull-up resistor embodiment, a VVM resistor 12 in the pull-down arrangement limits the current that can flow between Vcc 108 and ground 110 . Though less often used, it is still a valid application for the VVM resistor 12 . Further, although not illustrated, the VVM resistor 12 of the present invention may be employed as a well known current limiting resistor or in any other known application for a resistor.
[0073] An alternative pull-up arrangement is illustrated by the circuit 120 in FIG. 4, wherein the VVM resistor 12 establishes a voltage V+ 122 as the input for the device 124 , regardless of the voltage Vin 126 . The device 128 includes an open collector output transistor 130 . When the transistor 130 is open, the input line is pulled up to Vin 126 so that Vin=V+. When transistor 130 is closed, the input line is pulled down to ground so that Vin=0.
[0074] Many digital circuits use a 10kΩ or a 47kΩ resistor for pull-ups (and pull-downs). The exact value does not actually matter, as long as the resistance of the VVM resistor is high enough to prevent too much current from flowing. 10kΩ is likely the most common value, however, the 47kΩ resistor saves more power. Higher values for the VVM resistor 12 are possible depending on the characteristics of the chip.
[0075] As before, the pull-up VVM resistor 12 may also be applied directly, e.g., to a PCB or to another suitable substrate, such as a polymide or other polymer, as set forth in U.S. Provisional Patent application No. 60/370,975. The VVM resistor 12 in a pull-up or pull-down arrangement may further be implemented in a housing or device, which is soldered or otherwise electrically bound to a suitable substrate.
[0076] The VVM resistor includes an EOS switching material that uses conductive particles in an insulating binder via standard mixing techniques. In an embodiment, semiconductive particles and/or insulating particles may be added to the mixture. Tile insulating binder is chosen to have a high dielectric breakdown strength, a high electrical resistivity and high tracking resistance. The switching characteristics of the composite material are determined by the nature of the conductive, semiconductive, and insulative particles, the particle size and size distribution, and the interparticle spacing.
[0077] The interparticle spacing depends upon the percent loading of the conductive, semiconductive, and insulative particles and on their size and size distribution. In an embodiment, interparticle spacing is greater than 100 angstroms or 500 angstroms. Additionally, the insulating binder provides and maintains sufficient interparticle spacing between the conductive and semiconductive particles to provide a desired normal state resistance. The desired normal state resistance is also effected by the resistivity and dielectic strength of the insulating binder. The insulating binder material in an embodiment, has a volume conductivity of at most 1×10 −6 (ohm-cm) −1 .
[0078] Suitable insulative binders for the VVM include thermoset polymers, thermoplastic polymers, elastomers, rubbers, or polymer blends. The polymers may be cross-linked to promote material strength. Likewise, elastomers may be vulcanized to increase material strength. In an embodiment, the insulative binder comprises a silicone rubber resin manufactured by, for example, Dow Corning STI and marketed under the tradename Q4-2901. This silicone resin is cross-linked with a peroxide curing agent; for example, 2,5-bis-(t-butylperoxy)-2,5-dimethyl-1-3-hexyne, available from, for example, Aldrich Chemical.
[0079] The choice of the peroxide curing agent is partially based on desired cure times and temperatures. Many binders may be employed, however, as long as the material does not preferentially track in the presence of high interparticle current densities. In another embodiment, the insulative binder comprises silicone resin and is manufactured by, for example, General Electric and marketed under the tradename SLA7401-D1. Another binder that is self-curable and suitable for direct application to a substrate is discussed above and disclosed in Provisional U.S. Patent Application No. 60/370,975.
[0080] In an embodiment, the conductive particles have bulk conductivities greater than 1×10 (ohm-cm) −1 . In an embodiment, the conductive particles have an average particle size of less than 1000 microns. In an embodiment, 95% of the conductive particles have diameters no larger than 20 microns. In another embodiment, the particles are less than 10 microns in diameter.
[0081] Conductive materials that are suitable for use in the present invention include nickel, copper, aluminum, carbon black, graphite, silver, gold, zinc, iron, stainless steel, tin, brass, and metal alloys. In another embodiment, conducting polymer powders, such as doped polypyrrole or polyaniline may also be employed, as long as they exhibit stable electrical properties. In an embodiment, the conductive particles are nickel manufactured by for example, Atlantic Equipment Engineering, and marketed under the tradename Ni-120 and have an average particle size in the range of 10-30 microns. In another embodiment, the conductive particles comprise aluminum and have an average particle size in the range of 1-5 microns.
[0082] The semiconductive particles contemplated for use in the present invention have an average particle size less than 100 microns. In an embodiment, the bulk conductivity of the semiconductor particles is in the range of 10 to 1×10 −6 (ohm-cm) −1 . However, in order to enhance particle packing density and obtain optimum clamping voltages and switching characteristics, the average particle size of the semiconductive particles in an embodiment is in a range of about 3 to about 5 microns, or even less than 1 micron. Semiconductive particle sizes down to the 100 nanometer range and less are also suitable for use in the present invention.
[0083] One suitable semiconductive material is silicon carbide. The semiconductive materials, however, alternatively include: oxides of bismuth, copper, zinc, calcium, vanadium, iron, magnesium, calcium and titanium; carbides of silicon, aluminum, chromium, titanium, molybdenum, beryllium, boron, tungsten and vanadium; sulfides of cadmium, zinc, lead, molybdenum, and silver; nitrides such as boron nitride, silicon nitride and aluminum nitride; barium titanate and iron titanate; suicides of molybdenum and chromium; and borides of chromium, molybdenum, niobium and tungsten.
[0084] In an embodiment, the semiconductive particles are silicon carbide manufactured by for example, Agsco, #1200 grit, having an average particle size of approximately 3 microns, or silicon carbide manufactured by for example, Norton, #10,000 grit, having an average particle size of approximately 0.3 microns. In another embodiment, the compositions of the present invention include semiconductive particles formed from mixtures of different semiconductive materials; e.g., silicon carbide and at least one of the following materials: barium titanate, magnesium oxide, zinc oxide, and boron nitride.
[0085] In the VVM of the VVM resistor 12 of the present invention, the insulating binder is in a proportion of about 5 to about 70% by volume of the total composition. The conductive particles may comprise from about 10 to about 70% by volume of the total composition. The semiconductive particles may comprise from about 2 to about 70% by volume of the total composition.
[0086] According to another embodiment of the present invention, the VVM further includes insulative particles having a bulk conductivity of about 1×10 −6 (ohm-cm) −1 . An example of a suitable insulating particle is titanium dioxide having an average particle size from about 300 to about 400 angstroms produced by, for example, Nanophase Technologies. Other examples of suitable insulating particles include, oxides of iron, aluminum, zinc, titanium and copper and clay such as montmorillonite type produced by, for example, Nanocor, Inc. and marketed under the Nanomer tradename. The insulating particles, if employed in the composition, are in an embodiment present in an amount from about 1 to about 15%, by volume of the total composition.
[0087] Through the use of a suitable insulating binder and conductive particles, semiconductive particles and possibly insulating particles, having the preferred particle sizes and volume percentages, compositions of the present invention generally can be tailored to provide a range of clamping voltages from about 30 volts to greater than 2,000 volts. Further, combining proper concentrations of a suitable insulating binder, conductive particles, semi-conductive particles and possibly insulating particles, compositions of the present invention can be tailored to provide a range of useful resistivities for the VVM resistor of the present invention. In an embodiment, the VVM of the resistor 12 includes only conductive particles or conductive particles having an insulative coating mixed into an insulative binder.
[0088] Referring now to FIG. 5, a percolation curve plots a normalized resistivity of the VVM material when no EOS transient is present as a function of the percentage by volume of a suitable conductive filler. For purposes of illustration, the conductive filler may be assumed to be any of the conductive particles having one of the sizes disclosed above. The vertical axis shows normalized resistivity with wherein the value “one” represents the resistivity of the insulative binder, and the value “zero” represents the resistivity of the bulk filler. It should be noted that the percolation curve for the system could be shown in terms of absolute resistivity, in which case the vertical axis would span several orders of magnitude.
[0089] The concentration of conductive filler needed to significantly change the normal state resistance typically ranges from about 15 to 20% by volume, depending on the nature of the other ingredients present in the formulation. In a typical application requiring a very high resistivity, a conductive fill concentration of less than 20% typically provides a very high resistance, which may change very rapidly. As the concentration increases from 20% to 60 or 70%, the curve flattens significantly. An EOS material having 40% to 60 or 72% by volume conductive filler therefore produces a material having a discernable and repeatable resistivity.
[0090] By selecting and manufacturing a concentration in this range, a VVM resistor of a known and repeatable resistivity can be made. Moreover, VVM resistors having resistivities commonly used in known termination resistors, pull-up/pull-down resistors and current limiting resistors can be made. Of course, the overall resistance provided by the material is also a function of the amount used. A VVM resistor having a known and repeatable resistance can therefore be made by supplying a known quantity of a material of known resistivity. It should be appreciated then that knowing: (i) the desired resistance for the VVM resistor and (ii) the desired amount or the available space for application of the VVM resistor, a particular resistivity can be calculated and a particular conductive filler concentration can be extrapolated.
[0091] As observed in FIG. 5, a dip in resistivity occurs when the concentration of the conductive filler reaches approximately 65 to 72%. It is within this range when complete contact of the conductive metal spheres occurs. The dip in resistivity levels off at the bulk resistivity of the conductive filler. After reaching the complete contact concentration, the resistivity is essentially the resistivity of bulk metal, e.g., bulk nickel. The bulk metal resistivity is on the order of 1×10 −6 (ohm-cm) −1 , which is likely to be too low for most applications. For this reason, the upper end of the conductive filler concentration for the VVM resistor is preferably at or before the bulk metal dip, i.e., 65 to 72%. The particle size for the conductive component is one important factor determining where, within the 65 to 72% range, the dip will occur.
[0092] Referring now to FIGS. 6A to 6 C, an alternative application using known voltage variable materials, i.e., high resistance materials, is illustrated. That is, the VVM resistors 12 (FIGS. 1A to 1 C, 2 , 3 and 4 ) as heretofore described employ a VVM having a higher conductivity, i.e., having a lower resistivity when no EOS transient is present than in known applications of VVM. The VVM 152 of the alternative VVM resistor 150 illustrated in FIG. 6B, however, employs the VVM material, which is highly resistive upon the occurrence of an EOS transient, e.g., as disclosed in U.S. Pat. No. 6,251,513 B1, which has been incorporated by herein reference above.
[0093] [0093]FIG. 6A illustrates a known surface mount resistor 154 , which is soldered to a PCB 160 or other type of substrate, such as a flex-circuit or polymide (referred to herein as PCB 160 for ease of illustration), via electrodes 156 and 158 as is well known in the art. The resistor 154 includes a material having a fixed resistivity. FIG. 6B illustrates a sectioned view of the alternative VVM resistor 150 . A PCB 160 has a plurality of conductive, e.g., etched, mounting pads 162 and 164 . The electrodes 156 and 158 of the fixed resistor 154 are electrically coupled to the pads 162 and 164 , respectively, via solder fillets 166 and 168 . A layer of VVM 152 having a high resistance when no EOS transient is present is applied over the assembly to form the VVM resistor 150 . Normally, current flows through the resistor 154 , not the VVM 152 . During an ESD event, the layer of VVM 152 creates a highly conductive path from the pad 162 to the pad 164 . As described above, the VVM material 152 may be directly applied to the PCB 160 or the alternative VVM resistor 150 may be housed in a body (not illustrated), which solders to PCB 160 or other substrate.
[0094] Referring now to FIG. 6C, an equivalent circuit for the alternative VVM resistor 150 is illustrated. When no EOS transient is present, no current or little current flows through high resistivity VVM material 152 and the fixed resistor 154 performs its Ohmic function. As disclosed above, fixed resistor 154 may be a termination resistor, a pull-up or pull-down resistor, a current limiting resistor or be employed in any resistor application. When an ESD event occurs, the VVM material switches to a low resistivity, high conductivity state, so that the EOS transient may dissipate. As illustrated, the alternative VVM resistor 150 places the VVM material 152 in parallel with the fixed resistor 154 .
[0095] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages.
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The present invention provides a multifunction resistor having an improved voltage variable material (“VVM”). More specifically, the present invention provides a polymer VVM that has been formulated with a high percentage loading of conductive and/or semiconductive particles. A known length of the relatively conductive VVM is placed between adjacent electrodes to produce a desired Ohmic normal state resistance. When an electrostatic discharge event occurs, the VVM of the multifunctional resistor becomes highly conductive and dissipates the ESD threat. One application for this “resistor” is the termination of a transmission line, which prevents unwanted reflections and distortion of high frequency signals.
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This application claims priority to U.S. provisional application Ser. No. 60/435,210 filed Dec. 19, 2002.
BACKGROUND OF THE INVENTION
This application relates to a gas pin valve for a gas cylinder and specifically to a gas pin valve for a gas cylinder including tamper resistance and tamper evident features.
Typically, a gas cylinder is filled with a liquid or gas under a desired pressure. The gas cylinder is designed to withstand specific pressures and to deliver the gas and liquid at pressure to specific devices. Commonly, devices such as paintball guns or fire extinguishers use the pressurized gas within the cylinder to propel a paintball in the case of the paintball gun, or a fire suppression chemical in the case of a fire extinguisher. In any device, it is desired to maintain the gas or liquid within the cylinder at a given pressure until use. It is known to use a pin-type valve threaded into the outlet of the gas cylinder to control the outlet of gas pressure from the cylinder.
Typically, a pin valve includes a piston held against a seal by a spring. The spring is trapped between the piston and a threaded screw and provides a sufficient force within the gas cylinder to prevent unwanted expulsion of gas from the gas cylinder. Typically, gas pressure within the cylinder acts in concert with the spring to bias the piston against the seal. Gas is only expelled from the gas cylinder by overcoming the force of the spring and pressure exerted by gas within the cylinder.
The pin valve is threaded into the outlet of the gas cylinder and includes a threaded member having an inlet hole. When it is desired to release pressure from the cylinder, a pin extending from the piston through the opening is pushed downward. By pushing downward on the pin, the piston is lifted off the seal and gas pressure is allowed to escape through the inlet. The pin portion of the piston extends through the opening and is of a diameter smaller than the opening to allow gas pressure to be released from the gas cylinder.
As is appreciated, the spring force exerted by the spring onto the piston contributes a substantial portion of the biasing force used to maintain gas within the cylinder. The spring force exerted against the piston is determined by a distance between a rear end of the piston and a threaded member threaded into the body of the pin valve. Currently, the threaded member is machined with outer threads that are mated to internal threads that are fabricated within the body of the pin valve. The threaded member is then machined with an allen-type tool interface for assembly within the pin valve body against the force of the spring. As appreciated, machining of internal and external threads require expensive and time consuming machining operations. Further, such pin valves are commonly assembled to gas cylinders used in recreational devices where cost is a great factor determining commercial success. As appreciated, it is always desirable to decrease the cost of producing consumer goods.
Further, in some applications it is desirable to inhibit or evidence tampering of preset conditions. As appreciated, the preset spring force of the pin valve determines the amount of and point at which gas is exhausted from the gas cylinder. In some instances, tampering with this pin valve and the point and pressure required to release gas from within the gas cylinder can cause harm or injury. In such instances, it is desirable to evidence tampering by an operator in order to limit liability. Further, it is also desirable to prevent tampering by designing a mechanism that is destroyed upon modification and rendered unusable.
Accordingly, it is desirable to develop and design a pin valve that reduces production costs while also preventing and evidencing tampering.
SUMMARY OF THE INVENTION
An embodiment of this invention is a pin valve assembly including a plastic insert for holding a piston spring and piston against a seal.
A pin valve assembly includes a spring biasing a piston against a seal to seal a gas cylinder. The spring compresses a length determined by a distance between the insert and the plunger. The insert is pressed into an opening opposite the plunger and held in place by at least one barb extending inward from an inner diameter of a body of the insert.
The insert includes an opening to allow communication of gas pressure to a rear portion of the piston. The insert includes an outer diameter sized to correspond with an inner diameter of the body of the pin valve assembly. The inner diameter of the pin valve assembly includes at least one barb disposed to secure and prevent and evidence removal of the insert. The inset is pushed and pressed in opposite the piston to compress the spring and hold the piston against a seal. The insert is held in place by one or a series of barbs machined within the inner diameter of the pin valve body.
Accordingly, the pin valve assembly of this invention prevents and evidences tampering while reducing manufacturing costs.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:
FIG. 1 is a cross-sectional view of a gas cylinder and valve assembly according to this invention;
FIG. 2 is a cross-sectional view of the pin valve assembly of this invention;
FIG. 3 is an enlarged cross-sectional view of the pin valve assembly and delron insert; and
FIG. 4 is another embodiment of the pin valve assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , a gas cylinder assembly 11 is shown in cross section and includes a cylinder 13 and a pin valve assembly 10 . The pin valve assembly 10 is received within a threaded interface with the cylinder 13 . The pin valve assembly 10 includes a piston 28 with a pin portion 58 extending from an opening. The piston 28 is movable within the valve assembly 10 to control the flow of gas from the cylinder 13 .
Referring to FIG. 2 , the pin valve assembly 10 includes a body 12 that defines a first bore 14 and a second bore 16 . The outer features of the body 12 include a first threaded section 22 and a second threaded section 24 . Each of the sections are designed to accommodate either the specific gas cylinder or the specific device to which this pin valve 10 is attached. Preferably, the threads 22 are adapted and configured for mating to a gas cylinder (not shown). The threads 24 are adapted and configured to mate to the device to which the gas pressure held within the gas cylinder (not shown) is used. The body portion 12 also includes a hex nut portion 26 .
The hex nut portion 26 is adaptable for use by a tool to tighten and affix the pin valve assembly 10 either to the gas cylinder or to a device using the pressure within the gas cylinder. Further, other features on the body 12 include an o-ring land 44 adapted to fit a specific o-ring that would seal the device against the pin valve 10 . As appreciated, the external feature of the pin valve 10 can be of any type adapted for fitting to either the gas cylinder or the device using pressure within the gas cylinder. Note that it is within the contemplation of this invention that the external features of the pin valve 10 may be of any type and configuration known to one skilled in the art adapted to fit to either a gas cylinder or a device using pressure within the gas cylinder.
The piston 28 is of a length 52 that corresponds with a spring 30 and the insert 40 . The piston 28 includes a pin section 36 . The pin section 36 extends through an opening 58 in the body 12 . In this embodiment, the body 12 includes a concave portion 42 disposed in the opening area 58 . The concave portion 42 cooperates with the device using the pressure within the gas cylinder. The piston 28 is forced downward against a seal 32 . The seal 32 prevents the escape of gas pressure. The piston 28 is held against the seal 32 in part by the spring 30 . The piston 28 is also held against the seal 32 by gas pressure indicated by arrows 60 exerted on a rear portion of the piston 28 .
Threading a device onto the pin valve assembly 10 causes the pin portion 36 to engage a feature of the device that will push the piston 28 upward off of the seal 32 against the force of the gas pressure indicated at 60 and force of the spring 30 . This action opens gas pressure to be released into the device using pressure stored within the gas cylinder 13 .
The length between the upper portion of the piston 28 and the bottom portion of the insert indicated at 50 sets the amount of spring force exerted on the piston 28 against the seal 32 .
Holding the spring 30 downward against the piston 28 is the insert 40 . The insert 40 is pressed within an inner diameter 14 of the body 12 . Disposed on the inner diameter 14 of the body 12 are barbs 46 . At least one barb 46 disposed within this diameter to prevent and hold the insert 40 within the body 12 .
The insert 40 also includes an opening or inner diameter 38 to which gas pressure is communicated to a rear portion of the piston 28 . As appreciated, the insert 40 is held in place by the barbs 46 and does not require a plurality of threads either disposed on the exterior of the insert or interior of the insert. The insert 40 is simply pressed to a stop. The stop is a shoulder 62 that is disposed between inner diameters 14 and 16 .
Referring to FIG. 3 , the body 12 is shown in an enlarged view highlighting the diameter 14 into which the insert 40 is pressed. The insert 40 includes an outer diameter 48 that corresponds to the inner diameter 14 of the body 12 . The inner diameter 14 includes at least two barbs 46 . As appreciated, two barbs 46 are used, however, it is within the contemplation of this invention that only one barb may be used, or several barbs may be used as is required by the specific application and configuration. A worker skilled in the art would understand that the number of barbs is determinative only in regard to the specific application and that several barbs may be required in order to prevent removal of the insert 40 . However, in some applications only one barb 46 may be required to prevent and evidence removal of the insert 40 .
The insert 40 is preferably fabricated from a plastic material. Delron is preferred because it has specific properties that prevent the plastic deformation or creep over time. Other materials that exhibit similar characteristics may also be used for fabrication of the insert such as plastic material. The insert 40 includes chamfers 56 on each side to allow the inserts to be fully seated on the shoulder 60 . Preferably, similar chamfers 56 are disposed on each end of the insert 40 to allow for assembly of the insert 40 in any direction. The inner diameter 38 of the insert 40 is sized to correspond to the desired amount of gas pressure exerted on the back of the piston 28 . The inner diameter of the body 12 , 16 corresponds with the piston 28 and pressure exerted by gas within the gas cylinder as indicated by 60 .
In operation, the delron insert 40 is machined to the proper dimensions with a desired outer diameter 48 that corresponds to the inner diameter 14 . The insert 40 is then pressed within the body 12 to the stops 62 . The insert is pressed into the pin valve 12 after the seal 32 ; piston 28 and spring 30 have been installed within the insert body 12 . Pressing of the insert 40 into the inner diameter 14 engages the barbs 46 with the insert 40 . The barbs 46 are positioned and configured such that as the insert 40 is pushed within the diameter 14 , rearward movement or movement to remove the insert 40 is substantially prevented and not possible without completely destroying the insert 40 .
Referring to FIG. 4 , another embodiment of this invention is illustrated where the barbs 66 are disposed on the insert 40 . In this embodiment, the barbs 66 correspond with undercuts 64 within the inner diameter 14 of the body 12 . The insert 40 is pressed within the body 12 and the inner diameter 14 where the barbs 66 engage the undercut 64 to prevent removal of the insert 40 . An undercut 64 is all that is required on the inner diameter 14 of the body 12 and the barbs 66 are machined on the outer diameter 48 of the insert 40 . This embodiment, however, does require that the insert 40 be inserted into the inner diameter 14 in a specific direction in order for the barbs 66 to properly engage and prevent removal of the insert 40 .
As appreciated, many different configurations of barbs and undercuts are within the contemplation of this invention and a worker skilled in the art would understand that the specific configuration of the barbs relative to the body and insert are application specific and are within the scope of this invention.
The foregoing description is exemplary and not just a material specification. The invention has been described in an illustrative manner, and should be understood that the terminology used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, one of ordinary skill in the art would recognize that certain modifications are within the scope of this invention.
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A pin valve assembly includes a spring biasing a piston against a seal to seal an opening of a gas cylinder. The spring compresses a length determined by a distance between the insert and the plunger. The insert is pressed into an opening opposite the plunger and held in place by at least one barb extending inward from an inner diameter of a body of the insert. The insert includes an opening to allow communication of gas pressure to a rear portion of the piston. The inner diameter of the pin valve assembly includes at least one barb to secure and prevent removal of the insert.
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TECHNICAL FIELD
This invention relates generally to devices for assisting one in climbing and supporting oneself on a ladder, and particularly to devices of this category which are adapted to be strapped to each of one's feet.
PRIOR ART
Ladders are constructed with spaced foot supports, or rungs, extending between two frame members. In order to achieve portability, ladders are made lightweight; and to assist in this, the rungs, upon which one must stand, have a small cross section and thus supporting surface, particularly when compared with the area of the bottom of one's foot. Thus, when one climbs or stands on a rung of a ladder, his weight must be transmitted through a relatively small region of his foot, and this can be quite uncomfortable. In addition to this problem, unless one has his feet planted just right on a ladder, there is a tendency for the feet, or, in climbing, one foot, to rock; and, if one is not careful, he may actually slip from the ladder.
While the applicant is aware of there having been described in the patent literature certain portable platforms to assist one's stance on a ladder, e.g., U.S. Pat. Nos. 2,282,133 and 2,772,927, the applicant is unaware of there having been developed any device which would enable one to comfortably and securely climb and stand on a ladder.
It is an object of this invention to meet these deficiences and to provide a comfortable and safe foot support for climbing and standing on a ladder.
SUMMARY OF THE INVENTION
In accordance with this invention, a foot support is constructed to include a rigid, generally planar platform sized to approximate, or be slightly larger than, the area of the bottom of a shoe, this platform being adapted to generally rest on one rung of a ladder. Additionally, the platform is supported on a second and upper rung of a ladder by a bracket which is attached to a front end of the platform and extends upward and over the upper rung. The shoed foot of a wearer is secured to the platform by straps attached to the platform.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view, partially cut away, illustrating an embodiment of the invention.
FIG. 2 is a partial bottom view of the embodiment of the invention shown in FIG. 1, and particularly showing a front portion of the embodiment.
FIG. 3 is a pictorial view, partially cut away, illustrating another embodiment of the invention.
FIG. 4 is a bottom pictorial view, partially cut away, of the embodiment illustrated in FIG. 3.
FIG. 5 is a pictorial view of yet another embodiment of the invention.
FIG. 6 is a bottom pictorial view of the embodiment illustrated in FIG. 5.
FIG. 7 is a pictorial view, partially cut away, illustrating still another embodiment of the invention.
FIG. 8 is a detailed view, partially cut away, of the buckle assembly.
FIG. 9 is a side view illustrating yet another embodiment of the invention.
FIG. 10 is a bottom view of the embodiment illustrated in FIG. 9.
FIG. 11 is a top view, partially cut away, of the embodiment illustrated in FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIGS. 1 and 2, a ladder foot support stand 10 is constructed having a platform 12, typically made of wood, metal, or plastic and configured rectangularly to have an aproximate length of 10 to 15 inches and a width of approximately 4 to 5 inches and thus sufficiently to cover the dimension of most size shoes. A block 14, typically of the same material as platform 12, or as an extension of it, is positioned across the rear of platform 12, extending upward a distance of approximately 1/2 to 3/4 inch. It functions to provide a heel stop against which the rear of heel 16 of shoe 18 of a wearer is supported.
A first or rear pair of lace or tie-type straps 20 and 22 are each secured on end 24 to the rear side 26 of platform 12 by staples 28. When in use, as shown, these tie straps extend over block 14 and around opposite sides of shoe 18 and are tied together by knot 30 around the ankle of a user's foot 32. In this manner, the combination of block 14 and straps 20 and 22 effectively secure heel 16 of shoe 18 against movement on platform 12.
A second or front pair of lace tie-type straps 34 and 36 secure the front of a user's foot 32 on platform 12. One end of each of straps 34 and 36 are secured to a discrete side of sides 38 and 40 of platform 12 by staples 42. As shown, these straps then extend across and over the front or toe region 44 of user's shoe 18 and are tied together in a knot 46. Thus, the front region of a user's foot 32 is laterally secured, particularly being secured against side-to-side movement of the foot on platform 12.
The bottom side 48 of platform 12 generally rests on rung 50 of ladder 52. Typically, the area of contact with rung 50 is along a transverse narrow region of bottom side 48 somewhat closer to rear side 26 of platform 12 between front side 54 and rear side 26 of platform 12. The front region of platform 56 is supported on a second or upper rung 58 of ladder 52, this being accomplished by a curved bracket 60 which is attached to platform 12. Bracket 60 (FIG. 2) is generally flat over one end region 62 and is secured by bolts 64 to bottomside 48 of platform 12. Bolts 64 are arranged in a pattern which prevents bracket 60 from pivoting on platform 12. This feature may be enhanced by countersinking bracket 60 into bottom side 48 of platform 12. The mid region 66 of bracket 60 is curved upward, and an opposite end region 68 is curved outward and downward in the shape of a hook, and hook 70 is sized to engage rung 58 of ladder 52. By the combination of support from rungs 50 and 58, portions of one's weight are distributed between and on rungs 50 and 58.
In actual use, a user would employ a ladder foot support stand 10 on each foot 32, with each stand 10 being secured as shown in FIG. 1. To climb a ladder as, for example, ladder 52, the user would lift one foot sufficiently high and appropriately positioned to enable hook 70 to extend and lock around rung 58, rung 58 being just above a lower rung 50, on which platform 12 would make contact. Then, typically, the user would raise his other foot and repeat the process with it, except that the second foot would be raised to a point where the platform attached to it would initially be raised just above rung 58, and curved bracket 60 attached to it would be hooked over the next rung up from rung 58. Then, the platform on the second foot would be lowered to rest on rung 58. The process would be continued by elevating the first foot, and so on.
Alternately, a user is able to climb ladder 52 in a normal fashion without securing hook 70 around the next higher rung above that rung upon which platform 12 contacts. This manner of climbing, although not as safe and secure as that manner mentioned above, is faster and permits a user to reach his working elevation quickly and with a minimum of effort.
When one reaches the desired height, both feet are raised such that platforms 12 on both feet rest on the same rung with brackets 60 from each stand 10 being hooked over the next higher rung. For a comfortable and secure stance, the user causes the foot supports to tilt forward slightly and thereby distribute the user's weight between upper and lower rungs of a ladder. This incline enhances the safety of the user since the axis of his body is not vertical but pitched forward between a vertical line and the longitudinal axis of the ladder.
Whenever the user wishes to move to a different elevation, either upward or downward, he lifts each of his feet, one at a time, to unhook bracket 60 from the next higher rung and then moves to a new location, either upward or downward. Once at the new location, the user simply hooks brackets 60 over the next higher rung, as previously described.
Referring now to FIGS. 3 and 4, there is illustrated a second embodiment of the invention. In this embodiment, the top surface 100 of platform 102 is formed having a heel indentation 104 in end region 106. This indentation 104 and its stop surface 108 are sized to accept the heel of a user's shoe 18 and prevent heel 16 from sliding on platform 102 in any direction. Additionally, tie straps 20 and 22 function directly to hold the heel of a shoe down into indentation 104, and in keeping with this, tie straps 20 and 22 are attached by staples 24 to the sides 110 and 112 of platform 102, as particularly illustrated in FIG. 4. Otherwise, the structure of the embodiment shown in FIG. 3 is identical to the embodiment shown in FIG. 1, and the same component designations are employed.
Referring now to FIG. 5, there is illustrated a third embodiment of the invention which incorporates three variations in structure from that shown in FIG. 1. First, heel stop or block 200 is modified to provide a curved front surface 202, and by it (as shown) there is a greater area of contact between the heel 16 of user's shoe 18 and heel block 200 and thus greater protection against lateral slippage of the shoe. Second, a notch is formed transversely in the underside 204 of platform 206, being positioned approximately 30% of the length of platform 206 from the back of platform 206. Notch 208 is sized to fit on and around a rung of a ladder to prevent platform 206 from sliding either toward or away from the ladder. Third, the toe or front tie straps as employed in the embodiments of FIGS. 1 and 3 are replaced by a single strap 210 which is attached, such as by screws 212, to opposite sides 214 and 216 of platform 206 (FIG. 6). Typically, strap 210 would be 1 to 11/2 inches in width and constructed of a yieldable material to thus accommodate different size shoes. Alternately, it may be rigid or semi-rigid and taper forward to totally enclose the front of one's shoe.
Referring now to FIG. 7, there is illustrated a fourth embodiment of the invention which incorporates a variation in structure from that shown in FIG. 5. Heel stop or block 300 is modified to consist of a unitary piece of material which is bolted or otherwise secured to the rear portion 302 of platform 304 by bolts 306. One end region 308 of block 300 is turned upward approximately 90° with respect to the top 309 of platform 304, and this end region 308 is configured to provide a curved front surface 310 which increases the area of contact between heel 16 of user's shoe 18 and heel block 300.
Referring now to FIG. 8, there is illustrated an embodiment for securing user's foot 32 to foot support stand 10. In this embodiment, the tie-type straps previously mentioned are replaced with a buckle-type clasp 400 which includes a lace 402 having a buckle 404 secured to end 406 and a lace 408 having a plurality of spaced holes 410 therein. These holes 410 are sized so as to allow engagement of lace 408 with buckle 404, and thus, when laces 402 and 408 are positioned around user's foot 32 and are secured to each other, they secure user's foot 32 to support stand 10.
Referring now to FIGS. 9-11, there is shown another embodiment of the invention. As illustrated, the bottom surface 501 of foot support 500 is configured similar to the bottom of a regular shoe having a heel end region 502, a toe region 504, and an intermediately notched region 506. This notced region 506 would engage the rung of a ladder to support the user and prevents foot support 500 from sliding forward on the ladder rung. Notched region 506 permits foot support 500 to partially pivot on the ladder rung while still providing adequate support to the user. This allows the user to pivot a foot, and thus a foot support 500, while standing on a ladder without affecting the support provided him.
Toe region 504 is curved having an upwardly tapered surface 508 which contacts the ground as a user walks in these foot supports. Thus, tapered surface 508 is rolled forward during the walking process, and heel end region 502 pivots upward as would normally be the case while walking. The curvature of tapered surface 508 thus aids a user in walking with these foot supports strapped to his feet. A front portion 510 of toe region 504 is connected to bracket 512 via bolts or fasteners 514 (FIG. 10). These bolts 514 secure bracket 515 to bottom surface 501 of foot support 500.
As is better illustrated in FIG. 11, heel end region 502 has a notched heel stop 516 that provides lateral support in addition to back support for heel 518 of user's foot 520. Heel stop 516 need not rise significantly above the top of foot support 500 to be effective since its purpose is to provide a stop surface for user's foot 520 and to prevent this foot from sliding backward on foot support 500.
Front and back straps 522 and 524 restrain user's foot 520 onto the top of foot support 500, and these straps are secured to foot support 500 such as by bolts 526, as shown. Front strap 522 is illustrated as being a fixed continuous toe strap, but it may be made adjustable, such as by adding a buckle or snap assembly, if desired. Back strap 524 is illustrated as being adjustable by buckle assembly 528, but back strap 524 may also be made adjustable by being tied or otherwise secured by means not shown.
From the foregoing, it is to be appreciated that the applicant has provided a practical solution to the problem of comfortable and safe climbing and standing on a ladder, and the device which he has developed to do this is simple and inexpensive to manufacture.
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A foot support adapted to be employed with a ladder which employs a generally flat plate member attachable to a shoe and a bracket extending upward and then hooking downward from the toe end of the support. By this configuration, the foot and shoe of a user would basically be supported by a support resting on one rung of a ladder, and further support being provided by the bracket hooking over the next upper rung of the ladder.
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BACKGROUND OF THE INVENTION
This invention relates to brake and clutch assemblies and, more specifically, to piston operated brake and clutch assemblies wherein the clutch and brake are alternately engaged. The most pertinent prior art known to the applicant includes U.S. Pat. Nos. 3,177,994 to Jewson; 3,262,525 to Ehlke et al; and 3,696,898 to Sommer.
Various types of hydraulic clutch and brake mechanisms have long been employed where intermittent drive and braking is required for satisfactory operation. For example, such combination clutch and brake mechanisms are frequently employed in saw mills, in connection with rock crushers, and other similar applications.
Perhaps a more prominent field of use of such mechanisms has been their use as combination steering clutch and brake assemblies for controlling the locomotion and direction of crawler-type tractors.
Heretofore, difficulty has been encountered in attempting to design a satisfactory clutch and brake unit. Typical problems encountered are providing such a mechanism that is easily manufactured and subsequently serviced. One frequent cause for service is the failure of actuating pistons and seals since many such units employ pistons which experience both axial and rotary movement within the bores in which they travel.
A further problem of substantial moment has been providing such a mechanism that is axially compact, that is, of minimum size from its input shaft to its output shaft.
SUMMARY OF THE INVENTION
It is the principal object of the invention to provide a new and improved combination clutch and brake mechanism. More specifically, it is an object of the invention to provide such a mechanism wherein actuating pistons are not subject to rotational as well as axial movement to prolong the life thereof and wherein the axial dimension of the assembly is minimized.
An exemplary embodiment of the invention achieves the foregoing object in a structure including a rotatable input shaft and a rotatable output shaft coaxial therewith. A first pack of clutch elements is carried by the input shaft while a second pack of clutch elements is carried by the output shaft.
In addition, a first pack of brake discs is carried by the output shaft while a second pack of brake discs is carried by stationary structure. The arrangement is such that when the packs of clutch elements are compressed against each other, the output shaft will be driven while when the packs of brake discs are compressed upon each other, the output shaft will be braked.
An actuator, mounted for axial movement relative to the shafts and is operable in one direction of movement thereof to compress the clutch elements, while being operable in another direction of movement thereof to compress the brake elements. A piston is provided for axially shifting the actuator in either of the aforementioned directions and the same is located radially inwardly with respect to the shafts of either the clutch elements or the brake elements and further is non-axially spaced from the pack of elements with respect to which it is radially inwardly located.
According to one embodiment, the piston is single-acting and the assemblage is provided with a return spring while according to another embodiment, the piston is double-acting.
Where a single-acting piston is employed, a thrust bearing interconnects the piston and the actuator so that the actuator may rotate relative to the piston and not cause the piston to rotate within the chamber in which it is received. When the piston is double-acting, it is mounted for rotation with the output shaft in such a way as to be non-rotatable within the chamber in which it is received.
According to either embodiment, it is preferred that the actuator comprise a single pressure plate sandwiched between the clutch packs and brake packs to minimize axial length of the assemblage.
Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of one embodiment of a combination brake and clutch assemblage employing a single-acting piston; and
FIG. 2 is a sectional view of another embodiment of the invention employing a double-acting piston.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An exemplary embodiment of a brake and clutch mechanism made according to the invention employing a single-acting piston is illustrated in FIG. 1 and is seen to include an input shaft, generally designated 10, which is adapted to be driven and an output shaft, generally designated 12, which is adapted to be selectively coupled to the input shaft 10 or braked in a manner to be described more fully hereinafter.
The general organization further includes an outer clutch drum, generally designated 14, carried by the input shaft 10 and an inner clutch drum, generally designated 16, carried by the output shaft 12. A pack of clutch elements, generally designated 18, may be compressed in a manner to be described in greater detail hereinafter to couple the inner drum 16 to the outer drum 14.
In general terms, the mechanism further includes an outer, stationary brake drum, generally designated 20, which is secured by any suitable means to fixed structure and an inner brake drum, generally designated 22, carried by the output shaft 12. A pack of brake elements, generally designated 24, may be compressed to provide a braking function to brake the output shaft 12.
The general organization is completed by a reciprocal actuator, generally designated 26, which is operative to alternately press the clutch elements 18 and the brake elements 24 and which is operated by a reciprocal, single-acting piston, generally designated 28, which is operable to drive the actuator 26 in the direction of the clutch elements 18. A return spring 30 is provided for driving the actuator 26 in the direction of the brake elements 24.
Turning now to the input shaft 10, the same is journalled by any suitable bearings 31 in a sleeve 32 received within an appropriate opening in a housing 34 and retained therein by means of a nut 36. One end of the output shaft 10 is splined as at 38 to receive a hub 40 which is retained on the input shaft for rotation therewith by means of a nut 42.
The hub 40, near its radially outer extremity, mounts the outer clutch drum 14 by means of bolts 42. The outer clutch drum 14 includes a generally annular, inner surface provided with splines 44 which, in turn, slidably receive alternate ones of friction discs comprising the clutch pack 18. More specifically, a series of discs 46 are coupled to the outer clutch drum 14 for rotation therewith but may slide axially with respect thereto by reason of their engagement with the splines 44.
Interleaved with the discs 46 are friction discs 48 forming the remaining elements of the clutch pack 18. The discs 48 are slidably received on splines 50 on the cylindrical outer surface of the inner clutch drum 16 so as to be rotatable therewith and axially movable thereon.
As generally alluded to previously, the inner clutch drum 16 is carried by the output shaft 12 and, to this end, the latter includes a splined end 52 receiving the hub-like center 54 of the inner clutch drum 16. Retention is accomplished by a nut 56.
As a result of the foregoing construction, those skilled in the art will appreciate that when the clutch pack 18 and the discs 46 and 48 comprising the same are compressed against each other, the output shaft 12 will be rotationally coupled to the input shaft 10, while when there is no such compression, the input shaft 10 may continue to rotate without driving the output shaft 12.
If desired, one or more spacer plates 58 appropriately splined to the clutch components may be included.
Turning now to the actuator 26, the same is essentially a pressure plate having one pressure applying surface 60 facing the clutch pack 18 and an opposite pressure applying surface 62 facing the brake pack 24 and splined to the inner clutch drum 16 as at 63. The surfaces 60 and 62 are on opposite sides of the actuator 26 to define essentially a single pressure plate. When the actuator moves to the left as viewed in FIG. 1, the aforementioned compression of the clutch pack 18 occurs, while when moved to the right, the clutch will be disengaged and the brake engaged.
As can be seen in FIG. 1, the inner brake drum 22 is integral with the actuator 26. Like the inner clutch drum 16, the inner brake drum 22 carries radially outwardly extending splines 70 which engage brake discs 72 which rotate therewith and yet may move axially thereon. The brake discs form part of the brake pack 24 and are interleaved with the brake discs 76 and are splined by means of a splined surface 78 to the outer brake drum 20.
As generally alluded to previously, the outer brake drum 20 is fixed against rotation and, to this end, by means of bolts 80 and nuts 82, the same may be fixed in a series of peripheral locations to the stationary structure somewhat schematically indicated at 84. No reservation, however, is intended to the specific mode of attachment illustrated in FIG. 1. For example, as will be seen in connection with the embodiment illustrated in FIG. 2, it oftentimes is desirable to provide for axial adjustment of the location of the outer brake drum 20.
From the foregoing description, it will be appreciated that when the actuator 26 is moved to the right as viewed in FIG. 1, compression of the brake discs 76 and 72 upon themselves and upon the end of the stationary brake drum 20 will result in the braking of the output shaft 12. On the other hand, movement of the actuator 26 to the left will release the brake. Thus, the arrangement shown will cause alternate braking and coupling depending upon the position of the actuator 26 with respect to the clutch pack 18 and the brake pack 24.
The housing 34 includes a further opening opposite the opening receiving the input shaft 10 for mounting a cylinder structure, generally designated 90, which in turn mounts suitable bearings 92 for journalling the output shaft 12. Within the cylinder structure, seals 94 are provided to seal the interface of the cylinder structure 90 and the output shaft 12. The cylinder structure 90 may be formed of casting or the like and includes a fluid port 96 in communication with an annular chamber 98. Emerging from the chamber 98 and to the left thereof, as viewed in FIG. 1, is an annular cylinder 100 which receives one end of the piston 28. Suitable seals 102 are provided at the interface of the cylinder 100 and the piston 28.
The piston 28 is formed with an annular, radially outwardly extending flange 104 which is in engagement with the inner race 106 of a thrust bearing 108. Suitable pins 110 firmly secure the inner race 106 to the piston 28.
The outer race 112 of the thrust bearing 108 is in firm engagement with a shoulder 114 in the actuator 26 radially inwardly of the surfaces 60 and 62.
As a result of the foregoing construction, it will be appreciated that when fluid under pressure is passed through the port 96 to the chamber 98, the piston 28 will be directed to the left and such movement will be transmitted through the thrust bearing 108 to the actuator 26 to cause compression of the clutch pack 18 and relaxation of the brake pack 24. Because of the presence of the thrust bearing 108, rotational movement of the actuator 26 with the output shaft 112 will not cause rotation of the piston 28 within the cylinder 100. Thus, the piston 28 and associated seals 102 are subject to wear caused only by reciprocal movement and are not subject to wear caused by a combination of reciprocal and rotary movement within the cylinder 100.
To cause movement of the actuator 26 toward the right, as viewed in FIG. 1, when fluid under pressure is not being applied to the chamber 98, the return spring 30 is interposed between a web 120 extending between the inner clutch drum 16 and the hub 54, as well as an inwardly directed annular flange 122 forming a part of the actuator 26.
It should be observed that the configuration of the combination actuator 26 and inner brake drum 22 is such that thrust bearing 108 is located radially inwardly of the brake pack 24 and is not axially spaced therefrom. This enables the piston 28 to be similarly located, that is, radially inwardly from the brake pack 24 and not axially spaced therefrom. Consequently, the axial length of the assemblage, namely, the length from the end of the input shaft 10 to the end of the output shaft 12, is substantially reduced from prior art structures. Moreover, the unique arrangement of the piston 28 and the return spring 30 enables the use of a single piston 28 to cause alternate engagement of the clutch and brake of the invention.
Suitable manual control is also schematically illustrated in FIG. 1 in terms of a hydraulic system including a pump 130 associated with a reservoir 132 and a control valve 134. By manipulating the valve 134 so as to direct fluid under pressure from the pump 130 through a line 136 to the port 96, the clutch may be engaged and the brake disengaged. Conversely, by shifting the valve 134 so as to establish fluid communication with the reservoir 132, pressurization of the piston 26 may be relaxed, allowing the return spring to cause disengagement of the clutch and engagement of the brake.
Turning now to FIG. 2, a further embodiment of a combination brake and clutch mechanism made according to the invention is illustrated. The embodiment illustrated in FIG. 2 employs a double-acting piston with the consequence that the structure thereof differs in many respects from the structure illustrated in FIG. 1. However, for the sake of brevity, those structural components identical to or very nearly similar to those described previously in connection with the embodiment of FIG. 1 will be given like, but primed, reference numerals.
The output shaft 12' at its splined end 52' mounts an inner hub member 150 which, in turn, supports the inner clutch drum 16'. Unlike the embodiment in FIG. 1, in the embodiment in FIG. 2, the inner clutch drum 16' is separate from the inner hub 150 and is secured to the latter by means of a series of bolts 152. The purpose of this construction is to enable assembly of the mechanism to include a double-acting piston 154. More specifically, the hub 150 includes a conduit 156 having a port 158 facing the output shaft 12'. The latter, in turn, includes a central bore 160 which terminates in a radially extending segment 162 in alignment with the port 158 so that fluid under pressure may be directed through the interior of the output shaft 12' to the conduit 156.
The conduit 156 terminates in an annular chamber 170 defined in part by the hub 150 and in part by a radially inner portion of the inner clutch drum 16'.
A radially inwardly directed, annular lip 172 on the inner clutch drum 16' defines the radially outer wall of an annular cylinder receiving the piston 154 while a surface 174 on the hub 150 defines the radially inner wall of such cylinder. Suitable seals 176 are appropriately provided.
Intermediate its ends, the piston 154 includes a radially outwardly extending, peripheral flange 178 which, by a series of bolts 180, mounts the actuator 26'. A ring-like casting 190 is secured by means of a series of bolts 192 to the right-hand end of the hub 150 for rotation therewith. A formation on the casting 190 along with a formation on the right-hand end of the hub 150 define a chamber 196 adjacent the opposite end of the piston 154. The passage 198 in the casting 190 terminates in an annular, radially outwardly open recess 200 which is adapted to communicate with a conduit 202 extending to a port 204 in a stationary part of the mechanism.
A radially inwardly directed lip 206 on the casting 190 defines the opposite end of the aforementioned annular cylinder in connection with the right-hand portion of the surface 174 for receipt of the other end of the piston 154.
A valve 210 that is manually operable is employed for control purposes. Typically, the valve 210 will be a four-way valve or the like and includes a line 212 to the bore 160 as well as a line 136' to the port 204. A return line 138' to the reservoir 132' is provided and the latter is joined with a pump 130' in fluid communication with the valve 210. The arrangement is such that for one setting of the valve, fluid under pressure will be directed through the line 136' to the right-hand end of the piston 154 as viewed in FIG. 2, while the left-hand end of the piston 154 will be connected to the reservoir 132' through the line 212. This will cause the actuator 26' to shift to the left to engage the clutch.
In another position of the valve 210 fluid under pressure will be directed through the line 212 to the left-hand end of the piston 154 while the right-hand end of the piston will be connected through the line 136' to the reservoir 132' allowing disengagement of the clutch and engagement of the brake.
It will also be noted from the above-described construction, that the piston 154 does not rotate within its cylinder, both rotating together with the shaft 12.
It will also be recognized that the embodiment of FIG. 2 advantageously locates the piston 154 radially inwardly of the brake pack 24' and is non-axially spaced therefrom for the purpose of minimizing the axial length of the assemblage.
FIG. 2 also illustrates an advantageous feature that may be employed where required. More specifically, a portion of fixed structure 230, by means of a pin 232, pivotally mounts a link 234. The link 234 has its opposite end connected by a pivot pin 236 to a link 238 intermediate the ends of the latter. One end of the link 238 is connected by a pin 240 to an eye 242 on the exterior surface of the outer brake drum 20'. The opposite end of the link 238 is connected by a pivot pin 244 to the rod 246 of a single-acting cylinder 248.
In actuality, a plurality of the components 230-248, inclusive, are employed about the periphery of the outer brake drum 20'. The same serve to hold the outer brake drum 20' against rotation but allow controlled axial movement depending upon selective actuation of the cylinder 248 by a control system.
Thus, by extending the rods 246 of the cylinders 248, the outer brake drum 20' may be axially advanced towards the clutch as desired. This structure can be advantageously employed to adjust to an optimum degree, the length of axial travel of the actuator 26' between clutching and braking positions. Moreover, it provides the capability of allowing the output shaft 12' to be braked without disengagement of the clutch where such an operation is required simply by energization of the cylinder 248.
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An axially compact clutch and brake mechanism. Inner and outer concentrically mounted clutch and brake drums intermittently coupled respectively by packs of interleaved friction discs and plates are operated by a pressure plate disposed intermediate the clutch and brake disc and plate packs and responds to an annular hydraulic piston to alternately engage the clutch or engage the brake. Brake and clutch packs are axially spaced along the length of concentric input and output shafts while the piston is located radially inwardly of one of the packs and is not axially spaced therefrom so as to reduce the axial length of the assemblage. The mechanism further includes structure whereby the piston is not forced to rotate within its cylinder to thereby lengthen the life of the same.
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BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a suspension system for vehicles. More particularly, the present invention relates to a suspension system for vehicles that can be mounted utilizing a minimal amount of space and in which irregularities in the road surface are not directly transmitted to a frame of the vehicle.
(b) Description of the Related Art
The suspension system in vehicles improves ride comfort by absorbing shocks received through the wheels when the same encounter surface irregularities in the road. In addition to this main capability, suspension systems must also be designed to provide directional control, ease of handling, safety and stability.
Suspension systems comprise one or more control arms connecting the frame to the wheels, and springs and shock absorbers to absorb shocks transmitted from the road surface in the vertical direction. Accordingly movement of the wheels in relation to the frame is fully supported such that shocks and vibrations resulting from surface irregularities of the road are absorbed, and stability is provided when steering the vehicle.
The suspension system must satisfy three basic criteria: (1) ability to absorb shocks caused by road surface irregularities to provide ride comfort to the driver and passengers; (2) ability to prevent swaying of the vehicle during cornering, acceleration and braking; and (3) ability to maintain an appropriate level of vertical load on a surface of the wheel contacting the road such that vehicle stability is provided while turning, braking and accelerating, even when surface irregularities in the road are encountered.
To improve the above capabilities, those in the industry have put forth much effort into overall improvement and refinement of the suspension system, and in the development of improved springs and damping mechanisms.
The single control arm suspension system, also called the McPherson strut suspension system, is one example of a conventional suspension system. As shown in FIG. 11, the conventional strut-type suspension system comprises a strut assembly 212 consisting of a shock absorber 204 and a coil spring 202, the coil spring 202 surrounding the shock absorber 204; an insulator 206 interposed between a vehicle body 208 and an upper end of the strut assembly 212; a wheel carrier 210 fixed to a lower end of the shock absorber 204 and to which a wheel is rotatably mounted; and a lower control arm 216 which connects a lower portion of the wheel carrier 210 to a sub-frame 214.
With this structure, upward movement of the wheel and wheel carrier 210 caused by surface irregularities in the road is absorbed by the strut assembly 212. Accordingly, only a minimal amount of shock is transmitted to the vehicle body 208 and the frame 214.
However, problems result from such mounting of the strut assembly 212 in a vertical or slightly slanted state. That is, because of this vertical or near-vertical mounting of the strut assembly 212, a substantial amount of space is used by the suspension system. As a result, the vehicle body 208 must be large to provide sufficient clearance for the suspension system to operate. This acts to reduce the size of the engine and passenger compartments and limits the free layout design of the suspension system.
Further, as a substantial load is concentrated on the area of the vehicle body 208 to which the upper end of the strut assembly 212 is mounted, this area can weaken and eventually become damaged from the stress received. This results in the generation of vibrations such that handling and ride comfort are negatively affected, and noise is generated.
To remedy the above problem, some conventional configurations reinforce this area of the wheel carrier 208 to which the strut assembly 212 is mounted. However, such an addition increases overall manufacturing costs and the weight of the vehicle.
In the above, although the strut-type suspension system was given by way of example, the same drawbacks apply to all vertically-mounted suspension systems including the double wishbone suspension system and the multi-link type suspension system.
SUMMARY OF THE INVENTION
The present invention has been made in an effort to solve the above problems.
It is an object of the present invention to provide a suspension system for vehicles that can be mounted utilizing a minimal amount of space while maintaining its shock-absorbing and stabilizing capabilities such that the engine and passenger compartments can be enlarged.
It is another object of the present invention to provide a suspension system for vehicles in which shocks received from irregularities in the road surface are not directly transmitted to a vehicle body, thereby preventing damage to the vehicle body and improving handling and ride comfort.
It is still another object of the present invention to provide a suspension system for vehicles in which adjustments in shock-absorbing and clearances levels can be made to enable wide application of the suspension system to various types of vehicles.
To achieve the above objects, the present invention provides a suspension system for vehicles including a wheel carrier for rotatably supporting a wheel; an upper control arm having a first end connected to an upper end of the wheel carrier and a second end pivotally connected to a frame of the vehicle; a lower control arm having a first end connected to a lower end of the wheel carrier and a second end extending toward the frame of the vehicle; and a damper for converting an up-and-own motion of the lower control arm caused by shock transmitted from a road surface into a linear motion in a longitudinal direction of the vehicle and cushioning the linear motion the damper being mounted on a side member and connected to the lower control arm.
According to a feature of the present invention, a shock absorber is connected to the lower control arm and to the frame of the vehicle.
According to another feature of the present invention, the damper can be fixedly mounted to an exterior of a side member of the frame, or can be fixedly mounted within the side member of the frame.
In one aspect, the damper includes an upper casing fixedly mounted to a side member of the frame, the upper casing being hollow; a lower casing integrally formed downward from a right end portion of the upper casing and having a bottom end bent toward the second end of the lower control arm, the lower casing being hollow; a first shaft fixedly connected to the second end of the lower control arm and extending into the bottom end of the lower casing, a first gear being formed on an end of the first shaft extending into the lower casing; a second shaft extending along a length of the lower casing and into the upper casing, and having a second gear formed on a bottom end thereof to mesh with the first gear of the first shaft and a pinion formed on a top end thereof; an elastic member provided in a leftward end of the upper casing; and a rack bar having a stopper on a left end and a rack portion on a right end, the stopper contacting a right end of the elastic member and the rack portion meshing with the pinion of the second shaft.
According to another feature of the present invention, the elastic member is a coil spring.
According to yet another feature of the present invention, the damper further comprises an inner casing mounted in the leftward end of the upper casing, the elastic member being provided in the inner casing.
According to still yet another feature of the present invention, the damper further comprises a disc-shaped piston of a predetermined thickness provided between the elastic member and the stopper of the rack bar.
In another aspect, the damper includes an upper casing fixedly mounted to a side member of the frame, the upper casing being hollow; a lower casing integrally formed downward from a right end portion of the upper casing and having a bottom end bent toward the lower control arm, the lower casing being hollow; a beam fixedly mounted on the lower control arm and extending into the bottom end of the lower casing, a first gear being formed on an end of the first shaft extending into the lower casing; a first shaft extending along a length of the lower casing and into the upper casing, and having a second gear formed on a bottom end thereof to mesh with the first gear of the beam and a third gear formed on a top end thereof, a fourth gear rotating on a shaft mounted to an interior of the damper and meshed with the third gear; a second shaft provided extending between the lower casing and the upper casing, and having a fifth gear on a lower end thereof meshing with the fourth gear and a pinion on an upper end thereof; an elastic member provided in a leftward end of the upper casing; and a shock absorber mounted in the upper casing and having a damper rod extending in a leftward direction to be fixed to a left end of the upper casing and a rack bar extending in a rightward direction such that a rack portion formed thereon meshes with the pinion of the second shaft, the damping rod of the shock absorber extending through a middle of the elastic member.
According to a feature of the present invention, the elastic member is a coil spring.
According to another feature of the present invention, a cavity is formed between the upper casing and the lower casing, the third gear of the first shaft, the fourth gear, and the fifth gear of the second shaft being provided in the cavity.
According to yet another feature of the present invention, a guide member supports the shock absorber to enable the same to slide within the upper casing and prevent the shock absorber from sliding in a vertical direction.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and other advantages of the present invention will become apparent from the following description in conjunction with the attached drawings, in which:
FIG. 1 is a perspective view of a suspension system according to a first preferred embodiment of the present invention;
FIG. 2 is a front view of the suspension system shown in FIG. 1;
FIG. 3 is a sectional view taken along line III--III of FIG. 2;
FIG. 4 is a sectional view similar to FIG. 3 for illustrating the operation of a first damper during a jounce phase;
FIG. 5 is a sectional view similar to FIG. 3 for illustrating the operation of the first damper during a rebound phase;
FIG. 6 is a perspective view of a suspension system according to a second preferred embodiment of the present invention;
FIG. 7 is a front view of the suspension system shown in FIG. 6;
FIG. 8 is a sectional view taken along line VIII--VIII of FIG. 7;
FIG. 9 is a sectional view similar to FIG. 8 for illustrating the operation of a damper during a jounce phase;
FIG. 10 is a sectional view similar to FIG. 8 for illustrating the operation of the damper during a rebound phase; and
FIG. 11 is a front view of a conventional McPherson strut suspension system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
Certain terminology will be used in the following description for convenience and reference only and will not be limiting. The words "right", "left", "upper" and "lower" will designate directions in the drawings to which reference is made.
FIG. 1 shows a perspective view of a suspension system according to a first preferred embodiment of the present invention, and FIG. 2 is a front view of the suspension system shown in FIG. 1.
As shown in the drawings, the suspension system according to the first preferred embodiment of the present invention comprises a wheel carrier 2, an upper control arm 4 connecting an upper end of the wheel carrier 2 to a frame of the vehicle, a lower control arm 6 connecting a lower end of the wheel carrier 2 to the frame, and first and second dampers 8 and 10 which absorb shocks and vibrations received as a result of surface irregularities in the road.
The wheel carrier 2 rotatably supports a wheel 13 (see FIG. 2) on a support plate 12 thereof. Further, a hole 14 is formed in a center of the support plate 12 of the wheel carrier 2 such that, in the case where the suspension system is provided to drive wheels, a drive shaft (not shown) is inserted through the hole 14 of the support plate 12 to drive the wheel 13.
The upper control arm 4 connects the wheel carrier 2 to the frame. The upper control arm 4 is parabolic, and has a center connecting portion 16 provided approximately at its vertex and end connecting portions 18 and 20 formed on opposing ends of the upper control arm 4. The center connecting portion 16 is coupled to the upper end of the wheel carrier 2 using, for example, a ball-joint assembly, and the end connecting portions 18 and 20 are joined to the frame through, for example, bushing assemblies. With regard to the end connecting portions 18 and 20, it is possible to use other coupling structures that enable pivoting of the wheel carrier 2 in a vertical direction.
The lower control arm 6 extends from the wheel carrier 2 to the first damper 8 and includes an appendage 25 that branches off in a direction away from the first damper 8. The lower control arm 6 includes a first end 22 connected to the lower end of the wheel carrier 2 through, for example, a ball-joint assembly; a second end 24 connected to the first damper 8; and a third end 26 provided at an extremity of the appendage 25 and connected to the frame using, for example, a ball-joint assembly. The coupling of the second end 24 of the lower control arm 6 will be described in more detail hereinafter.
The second damper 10 is connected to the lower control arm 6 and a side member (S) of the frame. The second damper 10 includes a shock absorber 11, a lower connector 13 coupling the shock absorber 11 to the lower control arm 6, and an upper connector 15 joining the shock absorber 11 to the side member (S) of the frame. The lower connector 13 is connected to the lower control arm 6 at a position inward from the first end 22 of the same. With this configuration, the shock absorber 11 can be significantly shorter than that used in the conventional vertically-mounted suspension system. As the structure and operation of the shock absorber 11 is substantially identical to that used in the prior art, a more detailed description thereof will be omitted herein.
The first damper 8 is clamped to the side member (S) of the frame using, for example, a U-shaped clamp 9. The clamp 9 surrounds part of an exterior of the first damper 8 and is fixed to the side member (S). As shown in the drawings, the clamped portion of the first damper 108 is provided within the side member (S). However, the present invention is not limited to this structure and it is possible to mount the first damper 108 to an exterior of the side member (S) of the frame. Further, it is possible to use other mounting configurations to couple the first damper 8 to the side member (S) of the frame as long as the first damper 8 is securely fasted thereon.
FIG. 3 shows a sectional view taken along line III--III of FIG. 2. As shown in the drawing, the first damper 8 is tubular and its exterior is defined by an upper casing 30 and a lower casing 40, the upper and lower casings 30 and 40 being integrally formed. The upper casing 30 is mounted to the side member (S) of the frame by the clamp 9 (see FIGS. 1 and 2). The lower casing 40 extends downward from the upper casing 30 at a right end thereof, and a lower end of the lower casing 40 bends and extends in a rightward direction toward the second end 24 of the lower control arm 6 such that an L-shape is formed by the lower casing 40.
Extending from the second end 24 of the lower control arm 6 and entering the lower casing is a first shaft 36. One end of the first shaft 36 is fixedly mounted in the second end 24 of the lower control arm 6, and a first gear 42 is formed on an opposite end of the first shaft 36, the first gear 42 being, for example, a bevel gear. A second shaft 37 is provided extending across a length of the lower casing 40, the second shaft 37 protruding into the upper casing 30 and ending at a point corresponding to where the lower casing 40 bends. A second gear 44 is formed on a lower end of the second shaft 37 to mesh with the first gear 42 of the first shaft 36, the second gear 44 being, for example, a bevel gear. A pinion 46 is formed on an upper end of the second shaft 37.
Fixedly mounted in a leftward end of the upper casing 30 of the first damper 8 is an inner casing 32. A coil spring 28 is provided in the inner casing 32, and a piston 34 is positioned on a rightward end of the coil spring 28 such that the coil spring 28 provides biasing force against the piston 34 in a rightward direction.
A rack bar 48 is slidably provided in the upper casing 30. A rack portion 50 of a predetermined length is formed on a right end of the rack bar 48 and a stopper 52 is formed on a left end of the same. The rack portion 50 is meshed with the pinion 46 of the second shaft 37, and the stopper 52 contacts the piston 34. Here, the piston 34 is maintained in close contact with the stopper 52 by the biasing force of the coil spring 28.
With the above configuration, upward movement of the wheel 13 on the wheel carrier 2 is transmitted via the lower control arm 6. (see FIGS. 1 and 2) to the first damper 8 to be absorbed by the coil spring 28 provided therein. Also, downward force is applied on the wheel 13 even when the same follows a downward depression in the road by the transmission of the biasing force of the coil spring 28 such that sufficient vertical load on the surface of the wheel 13 contacting the road is maintained, thereby providing vehicle stability. Both the cushioning and maintaining of downward force on the wheel 13 is assisted by the second damper 10.
The operation of the first damper 8 will be described in more detail hereinafter.
FIG. 4 is a sectional view similar to FIG. 3 for illustrating the operation of the first damper 8 during a jounce phase. Referring to FIGS. 1, 2 and 4, when the wheel 13 encounters a bump in the road causing the same to travel upward, the wheel carrier 2 and the lower control arm 6 also move in the upward direction. As a result, the first shaft 36 fixedly provided in the second end 24 of the lower control arm 6 rotates in a direction as indicated by the arrow in the drawing.
Accordingly, the second shaft 37 rotates in a counterclockwise direction (in the drawing) such that the pinion 46 of the second shaft 37 moves the rack bar 48 in a direction toward the coil spring 28 as shown by the arrow. That is, by the meshing of the pinion 46 of the second shaft 37 with the rack portion 50 of the rack bar 48, the counterclockwise rotation of the second shaft 37 acts to move the rack bar 48 in a leftward direction. As a result, the stopper 52 of the rack bar 48 pushes the piston 34 against biasing force of the coil spring 28 such that the same is compressed. This acts to cushion the bounce of the wheel 13 when the same encounters irregularities in the surface of the road that force the wheel 13 upward.
FIG. 5 shows a sectional view similar to FIG. 3 for illustrating the is operation of the first damper 8 during a rebound phase. Referring to FIGS. 1, 2 and 5, when the wheel 13 travels downward as a result of a depression in the surface of the road, the wheel carrier 2 and the lower control arm 6 move downward together with the wheel 13. Accordingly, the second end 24 of the lower control arm 6 rotates in a direction as shown by the arrow in the drawing such that the first damper 8 operates in an fashion opposite to that described with reference to FIG. 4. As a result, the coil spring 28 rebounds and provides additional force to move the rack bar 48 in a rightward direction such that downward pressure is given to the wheel 13. Therefore, vertical load is applied on the surface of the wheel 13 contacting the road.
The above operation of the first damper 8 is continuously repeated as the vehicle is being driven, thereby fully absorbing shocks and providing stability as a result of the vertical load maintained on the surface of the wheel. As mentioned above, the operation of the first damper described with reference to FIGS. 4 and 5 is aided by the second damper 10.
Different springs with differing spring rates can be used for the coil spring 28 of the first damper 8 to vary the level of shock-absorbing strength and clearance of the vehicle. Accordingly, the first damper 8 can be made to be compatible to many different kinds of vehicles with different weights, and shock-absorbing and stability requirements.
FIG. 6 is a perspective view of a suspension system according to a second preferred embodiment of the present invention, and FIG. 7 is a front view of the suspension system shown in FIG. 6.
As shown in the drawings, the suspension system according to the second preferred embodiment of the present invention comprises a wheel carrier 102, an upper control arm 104 connecting an upper end of the wheel carrier 102 to the frame of the vehicle, a lower control arm 106 connecting a lower end of the wheel carrier 102 to the frame, and a damper 108 which absorbs shocks and vibrations received from surface irregularities in the road.
The wheel carrier 102 rotatably supports a wheel 113 (see FIG. 7) on a support plate 112 thereof. Further, a hole 114 is formed in a center of the support plate 112 of the wheel carrier 102 such that, in the case where the suspension system is provided supporting drive wheels, a drive shaft (not shown) is inserted through the hole 114 of the support plate 112 to drive the wheel 113.
The upper control arm 104 connects the wheel carrier 102 to the frame. The upper control arm 104 is parabolic, and has a center connecting portion 116 provided approximately at its vertex and end connecting portions 118 and 120 formed on opposing ends of the upper control arm 104. The center connecting portion 116 is coupled to the upper end of the wheel carrier 102 using, for example, a ball-joint assembly, and the end connecting portions 118 and 120 are joined to the frame through, for example, bushing assemblies. With regard to the end connecting portions 118 and 120, other coupling structures enabling pivoting of the wheel carrier 2 in a vertical direction can be used.
The lower control arm 106 extends from the wheel carrier 102 to be connected to the frame, and includes an appendage 125 that branches off in a rightward direction. The lower control arm 106 includes a first end 122 connected to the lower end of the wheel carrier 102 through, for example, a ball-joint assembly; a second end 124 connected to the frame using, for example, a bushing assembly, and a third end 126 provided at an extremity of the appendage 125 and connected to the frame using, for example, a ball-joint assembly.
In addition, a bar 138 is provided extending from the lower control arm 106 to the damper 108. One end of the bar 138 is fixedly connected to the lower control arm 106 and the other end of the bar 138 is inserted in the damper 108. The bar 138 is bent two times at substantially right angles such that upward and downward movement of the lower control arm 106 is transmitted as counterclockwise and clockwise rotation, respectively, with respect to the front view of FIG. 7.
The first damper 108 is fixedly mounted to the side member (S) of the frame using, for example, a U-shaped clamp 109 The clamp 109 surrounds part of an exterior of the first damper 108 and is fixed to the side member (S). As shown in the drawings, the clamped portion of the first damper 108 is provided within the side member (S). However, the present invention is not limited to this structure and it is possible to mount the first damper 108 to the exterior of the side member (S) of the frame. In addition, it is possible to use other mounting configurations to couple the first damper 8 to the side member (S) of the frame.
FIG. 8 shows a sectional view taken along line VIII--VIII of FIG. 7. As shown in the drawing, the first damper 108 is tubular and its exterior is defined by an upper casing 132 and a lower casing 140, the upper and lower casings 132 and 140 being integrally formed. The upper casing 132 is mounted to the side member (S) of the frame by the clamp 109 (see FIGS. 6 and 7), and the lower casing 140 extends downward from the upper casing 132 at a right end thereof. A lower end of the lower casing 140 bends and extends in a rightward direction toward the lower control arm 106 such that an L-shape is formed by the lower casing 140. Further, a cavity 141 is formed between the lower casing 140 and the upper casing 132, the use of which will be described hereinafter.
The bar 138 connected to the lower control arm 6 extends into the damper 108. That is, the bar 138 extends into the lower casing 140 and ends; at a position corresponding to where the same bends. A first gear 142 is formed on the end of the bar 138 inserted in the lower casing 140, the first gear 142 being, for example, a bevel gear. A first shaft 136 is provided extending across a length of the lower casing 140 and ends at a position in the cavity 141 formed between the lower casing 140 and the upper casing 132. A second gear 144 is formed on a lower end of the first shaft 136 to mesh with the first gear 142 of the bar 138, the second gear 44 being, for example, a bevel gear. A third gear 146 is formed on an upper end of the first shaft 36.
Provided adjacent to the third gear 146 of the first shaft 136 in the cavity 141 is a fourth gear 152. The fourth gear 152 is meshed with the third it gear 146, and these two gears 146 and 152 rotate in opposite directions as a result of their adjacent positioning. In addition, provided extending from the cavity 141 and into the upper casing is a second shaft 150. A fifth gear 154 is formed on a lower end of the second shaft 150 and a pinion is formed on an upper end of the same. The fifth gear 154 is provided adjacent to and meshing with the fourth gear 152. With the fourth gear 152 provided between the third gear 146 and the fifth gear 154, the latter two gears 146 and 154 rotate in the same direction.
Fixedly provided on a leftward end of the upper casing 132 is a first spring support 160. One end of a coil spring 128 is supported by the first spring support 160, and the other end of the coil spring 128 is supported by a second spring support 162. The second spring support 162 is integrally formed on a shock absorber 130. That is, the shock absorber 130 extends across a length of the upper casing 132 from the rightward end of the coil spring 128, which the shock absorber 130 supports with the second spring support 162, to approximately the right end of the upper casing 132.
A rack bar 147 is formed on a right end of the shock absorber 130, and a rack portion 148 of a predetermined length which meshes with the pinion 156 of the second shaft 150 is formed on the rack bar 147. In addition, a damping rod 129 of the shock absorber 130 extends from a middle area of the shock absorber 130, approximately where the second spring support 162 is formed, passes through a middle of the coil spring 128 and the first spring support 160, and is fixed to the left end of the upper casing 132. Also, a guide member 131 is provided at a portion of the shock absorber 130 between the second spring support 162 and the rack bar 147. The guide member 131 acts to support the shock absorber 130 as it undergoes sliding motion within the upper casing 132, and to prevent the shock absorber 130 from moving in a vertical direction therein.
With the above configuration, upward movement of the wheel 113 on the wheel carrier 102 is transmitted via the bar 138 mounted on the lower control arm 6 (see FIGS. 6 and 7) to the damper 108 to be absorbed by the shock absorber 130 and the coil spring 128 provided therein. Also, downward force is applied on the wheel 113 even when the same follows a downward depression in the road by the transmission of the biasing force of the shock absorber 130 and the coil spring 128 such that sufficient vertical load on the surface of the wheel 113 contacting the road is maintained, thereby providing vehicle stability.
The operation of the first damper 8 will be described in more detail hereinafter.
FIG. 9 shows a sectional view similar to FIG. 8 for illustrating the operation of the damper 108 during a jounce phase. Referring to FIGS. 6, 7 and 9, when the wheel 113 encounters a bump in the road causing the same to travel upward, the wheel carrier 102 and the lower control arm 106 also move in the upward direction. As a result, the end of the bar 138 connected to the lower control arm 106 also moves in an upward direction such that the end of the bar 138 provided in the lower casing 140 of the damper 108 rotates in a direction as shown by the arrow in FIG. 9.
Accordingly, the first gear 142 of the bar 138 rotates the second gear 144 of the first shaft 136 such that the same rotates in a clockwise direction (in FIG. 9). As a result, the clockwise rotation of the third gear 146 of the first shaft 136 rotates the adjacent fourth gear 152 in a counterclockwise direction (in FIG. 9). This, in turn, rotates the fifth gear 154 of the second shaft 150 in a clockwise direction (in the drawing) such that the pinion 156 of the second shaft 150 moves the shock absorber 130 in a leftward direction. That is, by the meshing of the pinion 156 of the second shaft 150 on the rack portion 148 of the rack bar 147 of the shock absorber 130, the clockwise rotation of the second shaft 150 acts to move the shock absorber 130 in a leftward direction.
As a result of the above, the second spring support 162 of the shock absorber 130 pushes against the biasing force of the coil spring 128 to compress the same, and the damping rod 129 of the shock absorber 130 is forced in to the same such that the cushioning action of the shock absorber 130 is operated. This acts to absorb the bounce of the wheel 113 when the same encounters irregularities in the surface of the road that force the wheel 113 upward.
FIG. 10 shows a sectional view similar to FIG. 8 for illustrating the operation of the damper 108 during a rebound phase. Referring to FIGS. 6, 7 and 10, when the wheel 113 travels downward as a result of a depression in the surface of the road, the wheel carder 102 and the lower control arm 106 move downward together with the wheel 113. Accordingly, the end of the bar 138 extending into the lower casing 140 of the damper 108 rotates in a direction shown by the arrow in FIG. 10 such that the damper 108 operates in an fashion opposite to that described with reference to FIG. 9. As a result, the shock absorber 130 and the coil spring 28 rebound and act to provide downward force to the wheel 113, thereby applying vertical load on the surface of the wheel 113 contacting the road.
The above operation of the first damper 108 is continuously repeated as the vehicle is being driven, thereby fully absorbing shocks, and providing stability as a result of the vertical load maintained on the surface of the wheel contacting the road.
Here also, as in the first embodiment, different springs with differing spring rates can be used for the coil spring 128 of the damper 108 to vary the level of shock-absorbing strength and clearance of the vehicle. Accordingly, the first damper 108 can be made to be compatible to many different kinds of vehicles with different weights, and shock-absorbing and stability requirements.
Although preferred embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concepts herein taught which may appear to those skilled in the present art will still fall within the spirit and scope of the present invention, as defined in the appended claims.
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Disclosed is a suspension system for vehicles including a wheel carrier for rotatably supporting a wheel; an upper control arm having a first end connected to an upper end of the wheel carrier and a second end pivotally connected to a frame of the vehicle; a lower control arm having a first end connected to a lower end of the wheel carrier and a second end extending toward the frame of the vehicle; and a damper for converting an up-and-down motion of the lower control arm caused by shock transmitted from a road surface into a linear motion in a longitudinal direction of the vehicle and cushioning the linear motion, the damper being mounted on a side member and connected to the lower control arm.
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BACKGROUND, SUMMARY AND OBJECTS OF THE INVENTION
This invention relates to improvements in chain saw design and more particularly, to a novel chain saw structure comprising flexible and resilient skid and vibration isolating skid mountings which cooperate to:
1. reduce handle vibration,
2. eliminate certain resonance, and
3. reduce tendencies for the saw to creep while resting on the ground and idling.
It is well known that internal combustion engine powered chain saws tend to produce vibrations which may cause the operator of the chain saw to become somewhat fatigued. In response to this problem, vibration isolation systems have been provided which, in general, are interposed between the drive assembly of the chain saw and the handles so that vibration is reduced in the handle portions of the chain saw. Examples of such vibration isolation systems are disclosed in U.S. Pat. Nos. 3,813,766 (June 4, 1974), 3,652,074 (Mar. 28, 1972), 3,698,455 (Oct. 17, 1972) and 3,542,095 (Nov. 24, 1970), all to Frederickson et al. and U.S. Pat. No. 3,972,119 (Aug. 3, 1976) to Bailey.
In addition, chain saws typically have a flat surface on the bottom portion of the engine housing or other structure upon which the chain saw may be rested when not in use. If the engine is idling, vibrations may resonate through the flat surface and cause the saw to creep or "walk" to a different orientation or location.
In most chain saws of this type, the crank shaft of the engine is oriented transversly to the longitudinal, front-to-back, central axis of the saw. It is the motion of the piston, connecting rod, and crank shaft which produce vibrations which contribute to handle vibration and to "creeping" effect.
In order to reduce the magnitude of these problems and in order to achieve other significant advantages, the invention provides a novel skid and skid mounting for use with a chain saw.
A major advantage of the novel, flexible and resilient skid presented through the invention, and its integrally associated, stress relieving mounting means (affording torsional stress relief at the rear chain saw handle and axial stress relief at the front chain saw handle) entails a marked reduction in chain saw handle vibration and an elimination of certain resonance, with a consequent reduction in operator fatigue.
The skid comprises a structure which is preferably made of elastically flexible sheet material and which preferably spans the length of the chain saw drive assembly below the chain saw. The skid may have a flat portion upon which the saw may be rested, including a foot rest portion which the operator can utilize to anchor the saw while he starts the engine by pulling on a conventional starter cable. The skid is attached to a front handle, and both the skid and handle are linked to a drive assembly by a first attachment means which provides stress relieving action with respect to both the front handle and the skid. Preferably, the first attachment means includes means for providing axial stress relieving action longitudinally of the saw and resiliently cushioned radial relative movement between the drive assembly and the handle and the skid, with respect to the longitudinally extending, axial stress relieving axis.
The skid also comprises a rear portion which extends upwardly from the foot rest portion and is connected to a rear handle of the chain saw by a second attachment means which provides torsional stress relieving action between the rear handle and the skid. Preferably, the second attachment means also comprises a resilient member which provides resiliently cushioned radial and axial relative movement between the rear handle and the skid.
In a preferred embodiment of the invention, the skid is formed from a single sheet of resilient, preferably metallic, leaf spring-like material. Bumpers are interposed between the skid and the lower portion of the drive assembly, which bumpers, together with the resilient members forming the parts of the respective attachment means, provide vibration isolating skid support means and reduce resonant vibration.
The front attachment means preferably comprises a slide bar rigidly connected to the drive assembly and oriented substantially parallel to the chain saw's longitudinal axis. Resilient sliding means in the form of a rubber diaphragm is mounted for axial sliding movement on the slide bar and connected to the front handle and to the skid. The preferred construction for the second attachment means comprises a shaft connected to the rear handle of the saw and having a central axis which may be inclined with respect to the saw's longitudinal axis. A resilient annular member is mounted for axial rotation on the shaft and is connected to the upwardly extending rear portion of the skid. Furthermore, in the preferred flexible skid, the body of the springlike skid, due to its flexibility, provides a lowered spring rate and hence a lowered vibration and a reduction or elimination of resonant frequency vibration tendencies.
The rear portion of the skid and the foot rest together serve as a guard for the hand of the user and provide protection against accidental actuation of the trigger by an obstruction when the saw is set on the ground.
The novel structural concepts heretofore set forth are intended to produce, as primary objects of the invention, a chain saw structure characterized by a reduction or minimization of handle vibration and a reduction or minimization of resonant frequency vibrations in the chain saw.
An additional object of the invention is to provide a skid upon which a chain saw may be rested and which is substantially vibrationally isolated from the drive assembly of the saw such that vibration of the skid is prevented or inhibited.
Another object of the invention is to prevent vibrational creep of a chain saw, while the chain saw is resting on the ground.
Still another object is to provide structure on a chain saw which performs the multiple functions of acting as a guard for the trigger and hand of the user, acting as a foot rest for aid in starting the motor, and acting as a rest surface for placing the chain saw on the ground.
These and other objects and features of the invention will be apparent to those skilled in the art from the following detailed description of the invention and from the drawing.
DRAWINGS
FIG. 1 is a side elevation of a chain saw fitted with a structure embodying the invention illustrating its relationship to the chain saw;
FIG. 2 is a top plan view of a preferred embodiment of the skid of the invention;
FIG. 3 is a simplified side elevation of a chain saw schematically illustrating the various type of relative motion between the skid and chain saw drive assembly;
FIG. 4 is a detailed side view in cross section of the second attachment means connecting the skid to the rear handle;
FIG. 5 is a detailed front plan view of the first attachment means linking the skid and the front handle of the chain saw with the drive assembly; and
FIG. 6 is a detailed side elevation view of the first attachment means of FIG. 5 showing certain parts in cross section.
DETAILED DESCRIPTION OF THE INVENTION
Before treating the improved aspects of the invention, a brief summary of the preferred chain saw context of the invention will be discussed.
PREFERRED CHAIN SAW CONTEXT OF THE INVENTION
The chain saw with which the instant invention may be used is of a type disclosed in the aforementioned United States Frederickson et al. U.S. Pat. Nos. 3,813,776 (June 4, 1974), 3,652,074 (Mar. 28, 1972), 3,698,455 (Oct. 17, 1972), and 3,542,095 (Nov. 24, 1970), the disclosures of which are hereby incorporated by reference.
As generally set forth in these patents, a chain saw 1 comprises a vibration generating drive assembly 2 which includes a piston and connecting rod driven crank shaft (not shown) having a rotational axis generally depicted by reference number 4, and a longitudinal axis 5.
Chain saw 1 additionally includes a cutter chain means 6 comprising a guide bar 7 upon which a cutter chain 8 is slideably supported. By virtue of transmission means now well known in the art, an internal combustion engine within the drive assembly 2 serves to drivingly cooperate with the cutter chain means 6.
The chain saw features a laterally extending front handle 9 which, on one side, is attached to a fuel tank assembly 11, providing an inertia or dampening function as described in the aforesaid Frederickson et al. patents. Handle 9 extends laterally around the chain saw and may be spaced radially forward of axis 4. As shown in FIG. 1, the front handle 9 has a flattened mounting portion extending in a direction parallel to axis 4 and passing beneath the drive assembly 2 where, as is explained more fully below, it attaches to certain parts of the structure of the invention.
The chain saw further includes a rear handle 10 which extends backwardly and slightly downwardly from inertia means 11 and serves as a housing for throttle trigger 12. Vibration isolating means 13 and 14 are interposed between the top of the engine drive assembly 2 and beneath the inertia or fuel tank means 11. A general appreciation of the structure and mounting for a suitable vibration isolating means 13 and 14 may be gained by making reference to the aforementioned Frederickson et al. patents.
The foregoing description briefly discloses the preferred chain saw context of the instant invention. However, it should be understood that the invention may be used with other chain saw designs, consisting with the overall teaching of this invention.
IMPROVED STRUCTURE OF THE INVENTION
As shown in FIG. 1, a skid 100 formed from a single piece of leaf-spring, sheet-like metallic material is connected to the chain saw by a first attachment means designated 102, and a second attachment means designated 104.
The skid 100 is preferably fabricated from resilient sheet metal such as aluminum (or possibly steel) but may be cast from metal or plastic. It comprises a front shield portion 106 which has a cut-out 108 allowing access to the front attachment means 102, an inverted channel portion 110 for receiving the bottom portion of front handle 9, a flat portion 112 upon which the chain saw may be rested, a foot rest portion 114 located below the rear handle 10 and to the rear of drive assembly 2, and an upwardly extending rear portion 116 which connects foot rest portion 114 to attachment means 104.
As seen in FIGS. 1 and 2, the skid has a second channel portion 118 defining a pair of holes 120 which accept shock absorbing and anti-rattling buttons or snubbers 122. A preferred structure for such buttons or snubbers is disclosed in the aforementioned U.S. Pat. No. 3,652,074 to Frederickson et al.
As illustrated in FIG. 2, the uppermost section of the rear portion 116 of the skid 100 has a hole 124 for receiving certain parts of second attachment means 104. Also, the inverted channel portion 110 has a pair of holes 126 for securing first connection means 102 thereto.
As can be seen from FIG. 2 the lateral dimensions of skid 100 may be varied to match the contours of the other parts of the chain saw for aesthetic and desired elasticity considerations. However, skid 100 must have sufficient width such that it can support the chain saw when rested on the ground without tipping and effectively shield the operators hand and the throttle zone. Preferably, skid portion 114 is substantially as wide as engine assembly 2 and considerably wider than handle 10. The thickness of the skid and the elasticity thereof will be selected to provide a leaf-spring action.
Rear portion 116 and foot rest 114 together function as a hand guard to prevent contact between the hand of the chain saw operator and brush, etc., during use. Further, rear portion 116 and foot rest 114 provide protection against accidental actuation of the throttle trigger 12 by warding off possible interfering objects as are often encountered in wooded areas.
From FIG. 3, the various relative movements between the skid 100 and the drive assembly 2 can be readily appreciated. To minimize handle vibration and vibration induced creep, it is believed to be important to isolate axial vibrations (indicated by arrow 120) from the front of the skid and torsional vibrations (indicated by arrow 118) from the rear of the skid. Moreover, with the structure herein described, radial vibrations at the front and rear of the skid of a lateral or vertical nature (indicated by arrows 126 and 128) will be restrained, as will axial stress indicated by arrow 130 at the rear of the skid and torsional stress indicated by arrow 116 at the skid front end, to the extent that it should be present.
First and second attachment means 102 and 104, as will become apparent from the detailed description set forth below, are specially designed to inhibit transmission of these variously directed vibrations, generated in the drive assembly and transmitted from the drive assembly to the skid.
In addition, the skid 100 can act as a leaf spring of desired elasticity operating in series with resilient members in the attachment means to reduce vibration and resonance. While, the optimum skid material is flexible it retains overall structural integrity, and operates to reduce overloading of the shock mounts 13 and 14 when the chain saw is being manipulated.
Axial vibration of the drive assembly causes relative movement in the directions of arrow 120 between the front of the skid and the front of engine assembly 2. Such axial vibration is largely dissipated and transmitted only slightly by friction between the skid and the front handle and engine assembly. Any axial vibration transmitted to the skid despite the stress relieving action of attachment means 102 is further absorbed as a consequence of the flexibility of the skid.
The generally free, axial sliding, stress relieving action of the components of front mount 102 serves another significant function. This freedom of axial movement, generally longitudinally of the chain saw, allows an axial stress relieving elastomeric diaphragm in mount 102 to remain relatively unstretched in an axial direction, when the saw is working. This serves to maintain the spring constant of the diaphragm at a desirably low level. This phenomena is believed to be particularly important during "bucking" and is believed to materially contribute to a reduction in vibration acceleration to below a "2G" level.
Attachment means 102 and 104 should preferably be designed to provide some degree of resiliently cushioned radial shock absorbing action between the skid and chain saw structure, in relation to radial vibrations depicted by arrows 126 and 128.
Lastly, it is also advisable to include structure in attachment means 104 to provide some resiliently cushioned axial stress relieving action between the rear handle 10 and the rear skid portion 116, in relation to axial stress 130.
The foregoing requirements are met by the inclusion of attachment means constructed as follows.
Referring to FIGS. 5 and 6, the front attachment means 102 is shown in detail.
As shown in FIGS. 5 and 6, mount 102 may comprise a slide bar or tube 200 rigidly mounted on drive assembly 2 by a bolt 201 and having a central axis 202 extending longitudinally of axis 5 of the chain saw 1. A nylon bushing 204 may be freely journaled and slide mounted on slide bar 200 and forms an annular socket for an annular rubber diaphragm 206. Diaphragm 206 may conform generally to the diaphragm structures featured in FIG. 2 of Frederickson et al. U.S. Pat. No. 3,813,776.
As can be seen in FIG. 6, the diaphragm, in cross section, may have a flared configuration which tapers outwardly. Diaphragm 206 and bushing 204 together comprise a relatively unrestrained slider means. A two part, annular case 208 supports the outer periphery of the slider means and connects it through bolt 210 to the inverted channel portion 110 of skid 100. Bolts 210 pass through skid holes 126, and through aligned holes of the flattened portion 212 of tubular front handle 9. In a modification of attachment means 102, a generally cylindrical steel ring (not shown) may circle and be bonded to the outer periphery of the diapgragm 206, as depicted in Frederickson et al U.S. Pat. No. 3,813,776.
As will be appreciated from the foregoing, this construction provides multiple degrees of relative movement or stress relieving capability between the skid 100, handle 9, and the engine assembly 2, as generally depicted by the arrows 116, 120, and 126, the primary freedom of action involving free axial movement 120 and resiliently cushioned radial movement 126.
Referring to FIG. 4, a cross section detail of the second attachment means 104 is shown.
A shaft 300 of mount 104 may be threaded into a bore 302 in the end of handle 10 and has a central axis 304 and an enlarged end 306. A sleeve 308, coaxial with shaft 300, may be journaled on the shaft and thus be rotatably mounted thereon. A washer 310 may rest against the inward side of enlarged end 306 and abuts sleeve 308. A generally annular resilient rubber member 312 may be provided which forms a grommet, surrounding sleeve 308 and thereby rotatably journaled on shaft 300. In this connection, sleeve 308 prevents significant axial "squeezing" of grommet 312. Member 312 may be restrained from axial translation by a washer 310 and the end of handle 10. Resilient member 312 is journaled within the interior of the skid hole 124 and thereby is connected to rear portion 116 of skid 100.
From the foregoing it can be seen that in response to torsional vibration in handle 10, the shaft 300 can rotate within the grommet 312, thus providing torsional stress relieving action between the skid and drive assembly. Furthermore, the resilience of rubber grommet 312 provides resiliently cushioned radial (illustrated by arrows 128) and axial (arrows 130) stress relieving, relative movement between the parts interconnected by attachments means 104.
In operation, the operator rests the saw on flat portion 112, places his foot on foot rest 114, and starts the engine of the chain saw by pulling on a starter cable (not shown). With one hand on handle 9 and the other on handle 10, the user depresses throttle trigger 12, thereby actuating chain cutting means 6. During use, rear portion 116 and foot rest 114 together protect the hand of the user from contact with interfering brush. When the chain saw is put down, it is again rested on flat portions 112-114 of skid 100 and may be left idling with very little "walking" or "creeping" along the ground occurring due to vibrations in the drive assembly 2. The resilient rubber grommet 312 of second attachment means 104, the rubber bumpers 122, and the rubber diaphragm 206 of first attachment means 102, and in particular the torsional stress relief of rear mount 104 and the axial stress relief of front mount 102 reduce handle vibrations and resonance tendencies.
The provision of attachment means 104, with its associated torsional stress relieving action, allows rotary motion of the handle about the axis 304 of shaft 300. This is believed to substantially eliminate a torsional resonance vibration in handle 10. In addition, the flexibility of skid 100 is believed to be responsible for a significant reduction in vibration transmitted from the power head 2 to the handle assembly.
SUMMARY OF MAJOR ADVANGAGES OVERALL SCOPE, AND UNOBVIOUSNESS OF THE INVENTION.
In describing the invention, various advantageous aspects have been delineated.
Primary advantages of the flexible skid and stress relieving skid mount invention reside in a reduction in handle vibration and an elimination of certain resonance.
The leaf-spring resilient flexibility of skid 100 advantageously eliminates certain resonance that would be present in rigid skid structures and reduces vibration transmission.
The freedom of axial movement of radial stress relieving diaphragm 206 operates to maintain a desirable, low spring rate characteristic in vibration isolating unit 102.
Another major advantage of the invention is believed to reside in the cooperation of the two attachment means 102 and 104, with rear attachment 104 providing a significant degree of torsional stress relieving action or torsional "decoupling" between handle 10 and skid 110. This "decoupling" is believed to eliminate certain resonance and handle vibration.
Other advantages of the invention are believed to reside in the basic simplicity and ease of fabrication of the skid and vibration isolation system.
In addition, the invention advantageously provides a guard for the hand of the user during operation of the saw, a foot rest to facilitate chain saw starting, and a trigger guard which protects against accidental actuation of the throttle trigger by an obstruction when the saw is set on the ground.
The flexibility of the skid and the axial and radial stress relieving and/or vibration isolating actions of the skid attachments are also deemed to be both collectively and individually noteworthy in relation to their vibrations and/or shock and/or rattle isolating and minimizing tendencies.
Significantly, the overall advantages outlined above are achieved through a marked departure from such prior art teachings as those exemplified by United States Nagashima et al. U.S. Pat. No. 3,945,119 (Mar. 23, 1976). Such prior art wholly fails to disclose or suggest the torsional and axial freedom of action provided respectively, by the attachments 104 and 102 of the present invention or the flexible, broad skid concept of this invention.
As will be apparent, advantages such as those summarized above may be achieved through configurations and arrangements differing from the disclosed and preferred embodiment.
For example, the slider means 204, 206 might be carried by the power head 2, with slide mount 200 being carried by the front handle/skid combinations.
In addition, grommet 312 might be carried by handle 10, with skid 100 supporting a grommet shaft akin to means 300/308.
Thus, those skilled in the chain saw vibration isolating art and familiar with this disclosure will readily envision additions, deletions, substitutions, reversals, or other modifications with respect to the disclosure heretofore set forth, all of which fall within the perview of the invention as set forth in the appended claims.
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A chain saw including a flexible, resilient skid mounted by means providing torsional and axial stress relieving action whereby enhanced vibration isolation is obtained and certain resonant vibration is eliminated.
A skid for use in a chain saw powered by a vibration inducing drive assembly. The skid has a flat portion for resting the saw on a surface, a foot rest portion, and an upwardly directed rear portion, and is connected to the remainder of the chain saw structure by a pair of attachment means. The first attachment means connects a front portion of the skid and a front handle to the drive assembly and provides for axial stress relieving relative motion between the skid and drive assembly. A second attachment means connects the upwardly directed rear portion of the skid to a rear handle and provides for torsional stress relieving relative motion between the skid and the handle.
The skid and its attachment means cooperate to reduce handle vibration, eliminate certain resonance problems, and minimize vibrationally induced creep tendencies when the chain saw is resting on the ground with its engine idling.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] N/A
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] N/A
BACKGROUND OF THE INVENTION
[0003] Field of the Invention
[0004] The present disclosure relates to space barrier devices, more particularly to a retractable space barrier installed at the entrance of a space wherein said space barrier is easily operated and secured so as to prevent others from using a private or reserved space.
[0005] Discussion of the Background
[0006] Unfortunately, reserve spots/spaces tend to be occupied by unauthorized users unless a guard or parking attendant is present. In an attempt to prevent unauthorized uses of reserved spaces, it has been proposed to provide at least barrier devices which normally block such reserved spaces, and which can be selectively moved to a non-blocking position only by a person authorized to do so.
[0007] Usually the devices used for reserving spaces are set in the ground within the determined area of the space and include a swingable portion which may be pivoted from a substantially horizontal position adjacent to the ground in which the vehicle can pass over the barrier to a substantially vertical position in which it blocks entry or exit of a vehicle from the space.
[0008] One of the disadvantages of the current barriers is the fact that a person needs to bend in order to pull up the barrier to put it in a vertical position. Another disadvantage is the use of an efficient locking mechanism in order to hold the barrier in position, more particularly in a vertical position.
[0009] Therefore there is a need to provide a space barrier installed in a space having a raising mechanism which is easily operated and secured so as to prevent others from using a private or reserved space.
SUMMARY OF THE INVENTION
[0010] The object of the present invention is to provide a simple and inexpensive space barrier that can be easily raised and lowered by an authorized user to provide access to an assigned space.
[0011] Specifically, it is an object of this invention to provide a space barrier device that is set into the pavement or ground level outside the space and which will prevent unauthorized entry into the space.
[0012] It is a further object of the invention to provide a space barrier device that may be locked against swinging motion by a non-authorized person.
[0013] To enable a better understanding of the objectives and features of the present disclosure, a brief description of the drawing below will be followed by a detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a general view the first exemplary space barrier guarding a space in accordance with the principles of the present disclosure.
[0015] FIG. 2 shows a general view of preferred displacement of the first exemplary space barrier embodiment in accordance with the principles of the present disclosure.
[0016] FIGS. 3A-3B show general views of the first exemplary space barrier embodiment in vertical position in accordance with the principles of the present disclosure.
[0017] FIGS. 4A-4C show detail views of the first exemplary space barrier embodiment in vertical position in accordance with the principles of the present disclosure.
[0018] FIGS. 5A-5D show general views of the preferred displacement of the locking bar mechanism in accordance with the principles of the present disclosure.
[0019] FIGS. 6A-6B show general views of the first exemplary space barrier embodiment in transitional position in accordance with the principles of the present disclosure.
[0020] FIGS. 7A-7D show detail views of the first exemplary space barrier embodiment in vertical position in accordance with the principles of the present disclosure.
[0021] FIGS. 8A-8B show perspective views of the first exemplary space barrier embodiment in horizontal position in accordance with the principles of the present disclosure.
[0022] FIGS. 9A-9D show detail views of the first exemplary space barrier embodiment in horizontal position in accordance with the principles of the present disclosure.
[0023] FIGS. 10A-10C are detail views of the actuator of the first preferred embodiment in vertical position in accordance with the principles of the present disclosure.
[0024] FIGS. 11A-11B are perspective views of exemplary structure applying the first preferred embodiment in accordance with the principles of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0025] As shown in FIG. 1 , the barrier 1 is intended to provide protection to an open space O while being configured to provide access when needed. The barrier 1 used for reserving a space comprises a base B, a display D, a main body or housing 20 , a locking bar mechanism 5 , a pivot member 3 and an actuator 4 . The barrier 1 is intended to be positioned at a horizontal position to permit access to the open space O and a vertical position to avoid access to the open space O. FIG. 2 shows the process of the barrier 1 moving from the horizontal position 1 A, to a transitional position 1 B and ending in the vertical position 1 C. The barrier 1 is intended to comprise a main body 20 , wherein said main body 20 comprises a first distal end 21 and a second distal end 22 . The material used for the barrier 1 is preferred to be a material that withstand variable weather conditions, such as hot weather, snow, dust and rain. Further main body 20 comprises a hollow main body and the at least said first distal end 21 is mechanically coupled to said pivot member B 1 . The second distal end 22 of said main body 20 comprises a display plate D. The display plate D comprises at least a recess to attach any desired member through said recess D 1 .
[0026] The main body 20 , as shown in FIG. 3A trough 3 B, is intended to achieve a vertically position with respect to the base B and floor. The base B, which is preferred to be fixed to the floor, supports the pivot member 3 which is attached to said base B. The pivot member 3 , as shown in FIG. 4A through 4C , comprises at least two vertical elements 30 , 31 fixed to base B and said vertical elements extends perpendicular to the base B or floor. At least one of the two vertical elements 30 , 31 comprises holes 301 , 300 . The holes 301 , 300 are configured to provide a locking feature depending on the position of the main body 20 . The dimension of the two vertical elements 30 , 31 extended perpendicular to the base B. Specifically the height and length of the two vertical elements 30 , 31 , depends on the dimensions of the main body 20 . For example, when the main body 20 is in horizontal position, as shown below, the main body 20 rests on top of the floor or base B, wherein the height of at least one two vertical elements extends vertically away from the main body 20 . Further when the main body 20 is in vertical position, as shown in FIG. 4A , with respects to the floor or base B, the length of at least one of the two vertical elements extends horizontally away from the main body 20 . In the instant case the first hole 301 is away from the main body 20 in order to provide enough space to engage a locking device, such as a padlock L. Therefore one of the purposes of the extension of the vertical elements 30 , 31 is to provide a locking mechanism for the horizontal position and vertical position of the main body 20 .
[0027] The pivot member 3 further comprises a pivot element B 1 that is mechanically coupled to the first distal end 21 of the main body 20 . The first distal end 21 comprises at least connection plates 200 , 201 with perforations that allow the pivot element B 1 to pass through. In the present disclosure the term “mechanical coupled” refers to a coupling between both parts maintaining a continuous connection while allowing a radius displacement or rotational motion of at least one of the elements. In the instant case the main body 20 is coupled to the pivot member 3 by means of the pivot element B 1 . The pivot element B 1 maintains a continuous connection between the pivot member 3 and the first distal end 21 but at the same time allows the radius displacement of the main body 20 in such way that a horizontal and vertical position of the main body 20 is achieved. The main body 20 is configured to provide a shape that wherein it is placed in vertical position rests on top of the base or floor B, as show in FIG. 3B . The vertical elements 30 , 31 are separated at a distance that is plenty to fit the first distal end 21 between said vertical elements 30 , 31 . The actuator 4 is further mechanically coupled to at least one of the vertical elements 30 , 31 by means of said pivot element B 1 , as show in FIG. 4C . The actuator 4 , which is explained below, comprises a pedal-plate element 42 , a fixing plate 40 and a pull-plate element 41 .
[0028] The locking bar mechanism 5 , as shown in FIGS. 5A through 5D , comprises an extended locking bar 50 and a pivot locking mechanism 500 . The extended locking bar 50 is positioned inside the main body 20 hollow body. The extended locking bar 50 is mechanically coupled to the pivot locking mechanism 500 by means of a second pivot element B 2 . The pivot locking mechanism 500 allows the radius displacement of the extended locking bar 50 simultaneously with the main body 20 displacement. The pivot locking mechanism 500 comprises a protrusion P. The protrusion P is vertically extended with respect to the base B. The protrusion P is located on top of the base B at a position that allows the main body 20 to rest on top of the floor while it is in horizontal position and to be covered by the main body 20 while it is in vertical position, as shown in FIG. 5A through 5C .
[0029] The extended locking bar 50 comprises a first end 51 and a second end 52 , wherein said second end 51 includes at least a hole R, as shown in FIG. 5D . The extended locking bar 50 is configured to extend away from the main body 20 during the vertical position, as shown in FIGS. 5A and 5D . The extension of the extended locking bar 50 is the result of the protrusion P extension with respect to the base B, as shown in exploded view of FIG. 5D . Due to the configuration and arrangement of the protrusion P, the extension of the main body 20 surrounds the extended locking bar 50 while it is positioned in the horizontal position. However, the extension of said extended locking bar 50 , more particularly said second end 52 extends away from the main body 20 providing a second location wherein the main body 20 is locked in said vertical position.
[0030] FIGS. 6A and 6B are directed to the transitional position of the space barrier 1 . The displacement of the main body 20 is assisted by an actuator 4 , as defined below. During the transitional position the actuator 4 pushes up the main body 20 by means of the pull-plate element 41 . As shown in FIGS. 7A through 7D , the main body 20 is located between the vertical elements 30 , 31 wherein said pull-plate element 41 contacts the main body 20 and pushes it up providing a radius displacement. The pivot element B 1 , which is mechanically coupled to the base B by means of the vertical elements 30 , 31 , assists to avoid vertical or horizontal displacement of the main body 20 , with respects to the base B and the actuator 4 , therefore allowing the rotational movement of both pieces.
[0031] FIGS. 8A and 8B are directed to the horizontal position of the space barrier 1 . As mentioned, the displacement of the main body 20 is assisted by an actuator 4 . During the horizontal position the actuator 4 is resting under the main body 20 . As shown in FIGS. 9A through 9D , the main body 20 is located between the vertical elements 30 , 31 wherein said pull-plate element 41 is at its lowest position and the pedal-plate element 42 is at its highest position with respects to the base B. The protrusion P is on top of the base B, mechanically coupled to the locking bar 50 and said locking bar 50 extends inside the hollow body of the main body 20 . The second pivot element B 2 , which mechanically couples the protrusion P and said locking bar 50 , is rotationally aligned with the first pivot element B 1 . In other word, the second pivot element B 2 is not vertically nor horizontally aligned with the first pivot element B 1 but the radius displacement in said first pivot element B 1 is aligned with the radius displacement of the main body 20 . As mentioned above, another feature of the space bar is to provide a vertical element which extends away from the main body for locking purposes. As shown in FIG. 9D , when the main body 20 is in horizontal position at least one two vertical elements' height extends vertically away from the main body 20 .
[0032] Another important feature, as shown in FIG. 10A through 10C , is the actuator 4 which assist the user to move the space barrier 1 into a vertical position for reserving spots, more particularly pulls up the main body 20 from a horizontal position to a vertical position. Mainly the actuator 4 comprises a pedal-plate element 42 , a fixing plate 40 and a pull-plate element 41 . The fixing plate 40 is mechanically coupled to the first pivot element B 1 . The pull-plate element 41 is fixed to the fixing plate 40 and extends perpendicularly and away from said fixing plate 40 towards the main body 20 . The pull-plate 41 is intended to contact the main body 20 while the main body 20 is in horizontal position and transitional position, wherein said pull-plate 41 is located between the main body 20 and the base B and/or floor. The pedal-plate element 42 is fixed to the fixing plate 40 and extends vertically away from the fixing plate 40 and the main body 20 . The purpose of the pedal-plate element 42 is to provide a surface wherein the user applies force using the foot and said force is transmitted to the pull-plate 41 which in turns pulls ups the main body 20 in order to achieved a vertical portion.
[0033] Further, FIG. 11A through 11B , shows different shapes for the main body 20 . The actuator 4 , similar to previous description, is intended to contact the main body 20 and pull up said main body 20 . The main body is a hollow body wherein said locking bar 50 extends in the vertical position. A padlock L, as mentioned above, is used to lock the main body 20 in a vertical position.
[0034] While the invention has been described as having a preferred design, it is understood that many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art without materially departing from the novel teachings and advantages of this invention after considering this specification together with the accompanying drawings. Accordingly, all such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by this invention as defined in the following claims and their legal equivalents. In the claims, means-plus-function clauses, if any, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.
[0035] All of the patents, patent applications, and publications recited herein, and in the Declaration attached hereto, if any, are hereby incorporated by reference as if set forth in their entirety herein. All, or substantially all, the components disclosed in such patents may be used in the embodiments of the present invention, as well as equivalents thereof. The details in the patents, patent applications, and publications incorporated by reference herein may be considered to be incorporable at applicant's option, into the claims during prosecution as further limitations in the claims to patentable distinguish any amended claims from any applied prior art.
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A space barrier for preventing the unauthorized use of reserved spaces comprising a vertical locking mechanism and a raising mechanism. The raising mechanism comprising at least a pedal-like component welded to a push up member for displacing in a rotational matter the space barrier from a horizontal position to a vertical position. The raising mechanism is useful for avoiding lower back injuries or for assisting user with lower back injuries. Further the locking mechanism assist the parking barrier to hold the vertical position while avoiding the entry or exit of a vehicle from the parking space.
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RELATED APPLICATION
[0001] This application is a U.S. national stage application of International Application No. PCT/US2008/066742 filed Jun. 12, 2008, which designates the United States of America, and claims the benefit of U.S. Provisional Patent Application Ser. No. 60/943,507, filed Jun. 12, 2007, the entire disclosure of which is hereby incorporated by reference.
TECHNICAL FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to recombinant DNA molecules encoding plasmids in Escherichia coli, including a new inducible expression plasmid and methods for protein production as well as protein purification of a protein expressed by an expression plasmid of the disclosure (e.g. the large fragment of Thermus aquaticus DNA polymerase I).
BACKGROUND OF THE DISCLOSURE
[0003] Enzyme structure and function studies require increasingly large amounts of pure enzymes. For example, to crystallize more complicated structures such as a DNA polymerase in a ternary complex with DNA plus an in-coming nucleotide, multi-milligram quantities of the enzyme are necessary to define and to optimize crystallization strategies, or to measure individual steps in an enzyme reaction pathway, transient kinetic methods require that the enzyme be present in reagent concentrations. It is common for research enzymology labs to use recombinant DNA technology to produce workable amounts of enzymes typically using Escherichia coli ( E. coli ) because it is inexpensive and easy to culture in shake-flasks. In addition, over the course of the past two decades much attention has been focused on strong promoter systems to improve heterologous gene expression in E. coli. High yields have been reported for many different enzymes but this usually refers to a high yield per cell in relatively low cell density cultures. Overall yields per culture batch or cycle were typically a few to tens of milligrams which were sufficient in most cases for starting crystallization efforts or for several kinetic experiments. The production of hundreds of milligram quantities of an enzyme using E. coli usually requires fermentation technology, equipment, and methods such as stirred fermenters with nutrient feeding capabilities that are unavailable to the average enzymology laboratory that must rely, instead on floor model gyratory shaker-incubators.
[0004] Existing expression vector systems based upon the strong and tightly controllable promoters from bacteriophage, e.g., phage lambda, have been widely used for high specific cell yields of recombinant products. These vectors are typically controlled by the temperature-sensitive lambda repressor gene, λcI857, that may be located in the host chromosome, on an accessory plasmid, or on-board the expression vector itself. While popular, cI857-controlled expression vectors can only be induced by a temperature jump typically requiring a rapid temperature increase from a non-permissive 32° C. to 42° C. to inactivate the repressor. Rapid temperature jumps are, however, difficult to accomplish in multi-vessel, shaker-incubators.
SUMMARY OF THE DISCLOSURE
[0005] The present disclosure provides, in some embodiments, a high copy number expression plasmid, that is may be inducible by chemical induction and/or temperature induction or both, that may have a moderate to high cell density capability in shake-flasks, may have host strain “portability” and may provide high yield of recombinant products.
[0006] In some embodiments, a vector of the disclosure may comprise a promoter, e.g. a powerful rightward promoter from bacteriophage lambda, cloned into the high copy-number plasmid, pUC19. This promoter/copy-number combination may provide high levels of transcription following induction. The promoter/gene transcriptional unit may be separated from the plasmid origin of replication by the T1T2 transcription terminators from the rrnB operon of E. coli thus preventing post-induction transcription from interfering with plasmid replication/stability. Expression may be controlled by a modified lambda repressor gene, λcI ts ind + , “on-board” the plasmid thus making it possible to rapidly screen a variety of host strains to optimize expression yields, stability, and the solubility of recombinant products. This repressor may allow use of chemical or temperature induction or both in recA + strains which may be more robust than typical recA − cloning hosts. The disclosure describes, in one example, use of a plasmid, pcI ts ind + , to express a modified version of the large fragment of Taq DNA polymerase I, as a test enzyme, using all three modes of induction, chemical alone, temperature alone, or both, in shake-flasks routinely achieving final cell densities of 9 to 12 A 600 /ml and yields of purified enzyme in the range of 30 to 35 mg/liter of culture and 100 to 300 mg per batch.
[0007] In some embodiments, the compositions, systems and methods disclosure relates to an isolated DNA comprising a sequence of SEQ ID NO: 1. The disclosure provides a recombinant plasmid comprising an isolated DNA comprising a sequence of SEQ ID NO: 1. In some embodiments, the plasmid is a vector. The vector may be a cloning vector and/or an expression vector. The disclosure also related to a microorganism comprising DNA comprising a sequence of SEQ ID NO: 1.
[0008] In some embodiments, the disclosure relates to a self-replicating nucleic acid molecule comprising: a promoter; at least one inducible repressor; a high copy number origin of replication; a sequence able to prevent transcription from the promoters from entering the region comprising the origin of replication; and a multiple cloning site wherein at least one nucleic acid encoding a protein of interest may be cloned. The promoter may be a promoter of the bacteriophage lambda and may be exemplified in non-limiting embodiments by the rightward promoter of bacteriophage lambda or the leftward promoter of bacteriophage lambda.
[0009] In some embodiments, the compositions, systems and methods of the disclosure relate to inducible repressor may be a temperature-inducible repressor. In some embodiments, the inducible repressor is a chemically-inducible repressor. The inducible repressor may be a temperature and chemically-inducible repressor. For example, a temperature and chemically-inducible repressor may be a lambda repressor λcI ts ind + . In some embodiments, the promoter is controlled by the repressor.
[0010] The disclosure also provides methods of producing at least one protein, comprising inducing expression of the at least one protein using a recombinant plasmid comprising an isolated DNA having a sequence of SEQ ID NO: 1, wherein inducing comprises temperature induction. In some embodiments, inducing further comprises chemical induction. The recombinant plasmid comprising an isolated DNA having a sequence of SEQ ID NO: 1 may further comprises at least one nucleic acid encoding the at least one protein that is being produced by the method.
[0011] In some embodiments, methods of the disclosure relate to of producing at least one protein, comprising inducing expression of the at least one protein using a recombinant plasmid comprising an isolated DNA having a sequence of SEQ ID NO: 1, wherein inducing comprises chemical induction. The inducing may further comprises temperature induction.
[0012] The disclosure also relates to protein production systems comprising a self-replicating nucleic acid molecule comprising: a promoter of bacteriophage lambda; a high copy number origin of replication; a sequence able to prevent transcription from said promoters from entering the region comprising the origin of replication; and a multiple cloning site; and an inducible repressor located on a chromosome.
[0013] In some embodiments, the self-replicating nucleic acid molecule and the repressor may be located in a living organism. In some embodiments, the repressor may be located on a host chromosome in the living organism.
[0014] In some embodiments, a protein production system is provided comprising a self-replicating nucleic acid molecule comprising: a promoter of bacteriophage lambda; a high copy number origin of replication; a sequence able to prevent transcription from said promoters from entering the region comprising the origin of replication; a multiple cloning site; and an inducible repressor.
[0015] The disclosure also relates to methods for protein purification comprising: a) obtaining a cell lysate from a cell comprising DNA having a sequence of SEQ ID NO: 1; b) treating the cell lysate with heat to denature cellular proteins; c) precipitating and removing cellular DNA thereby obtaining a supernatant comprising the denatured cellular proteins; d) applying the supernatant on a system of two chromatography columns, the first column comprising a cation-exchanger and the second column comprising an affinity-chromatography column; and eluting the proteins, thereby obtaining purified proteins. In some examples, the method may be used with the protein production system of the disclosure. Thereby proteins that are produced using the inducible, high-copy number expression plasmids of the disclosure may be purified. In some embodiments, the purification methods are rapid and efficient.
[0016] In one embodiment, which may use materials and methods of the embodiments described above, an E. coli -based protein production system is provided. The system may include an E. coli cell having a self-replicating nucleic acid molecule. The self-replicating nucleic acid molecule may include: a promoter of bacteriophage lambda, a high copy number origin of replication, a sequence able to prevent transcription from said promoters from entering the region comprising the origin of replication, and a sequence encoding an LdK39 protein or fragment thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Some specific example embodiments of the disclosure may be understood by referring, in part, to the following description and the accompanying drawings, wherein:
[0018] FIG. 1 shows a diagram depicting a partial restriction site map for pcI ts ,ind + modKlenTaqI showing the restriction sites used for the insertion of the modified KlenTaq I gene, mKlenTaqI; as well as transcription terminators, T1T2; origin of replication, pUC19 ori; the β-lactamase gene, AMP; the lambda repressor, pcI ts ,ind + ; and the rightward promoter, λP R in accord with one embodiment of the present disclosure;
[0019] FIG. 2 shows growth curves comparing the cell density of temperature-induced cells with chemically-induced cells over time in accordance with one embodiment of the present disclosure;
[0020] FIG. 3 depicts a comparison of protein yields for both temperature-induced cells and chemically-induced cells in accord with one embodiment of the present disclosure;
[0021] FIG. 4 depicts protein yields for cells that were both temperature- and chemically-induced in accordance with one embodiment of the present disclosure;
[0022] FIG. 5 shows a growth curve for large-scale shake-flask expression using chemical- and temperature-induction in accordance with one embodiment of the present disclosure;
[0023] FIG. 6 depicts protein yields for large-scale shake-flask expression using chemical and temperature induction in accordance with one embodiment of the present disclosure;
[0024] FIG. 7 depicts an elution profile where the major peak corresponds to purified modKlenTaq1 in accordance with one embodiment of the present disclosure;
[0025] FIG. 8 shows a gel analysis of the column fractions used in the preparation of FIG. 7 wherein 5 μl aliquots from peak column fractions were analyzed by 12% SDS-PAGE, in accordance with one embodiment of the present disclosure;
[0026] FIG. 9 shows a diagram depicting another partial restriction site map in accordance with one embodiment of the present disclosure;
[0027] FIG. 10 shows a diagram of a partial restriction map of the Leishmania donovani kinesin 39 (LdK39) gene;
[0028] FIG. 11 shows an expression vector containing a portion of the LdK39 gene, according to an embodiment of the present disclosure;
[0029] FIG. 12 shows a growth curve for the vector of FIG. 11 in E. coli in small-scale shake-flask expression using chemical only- and chemical and temperature-induction in accordance with one embodiment of the present disclosure;
[0030] FIG. 13 depicts protein yields for small-scale shake-flask expression of the vector of FIG. 11 in E. coli using chemical and temperature induction in accordance with one embodiment of the present disclosure;
[0031] FIG. 14 depicts antibody detection of a Flag-tag added to the LdK39 protein as expressed in a vector similar to that of FIG. 11 (the vector of FIG. 11 with Flag sequences added) in E. coli.
[0032] While the present disclosure is susceptible to various modifications and alternative forms, specific example embodiments thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific example embodiments is not intended to limit the disclosure to the particular forms disclosed herein, but on the contrary, this disclosure is to cover all modifications and equivalents.
DETAILED DESCRIPTION
[0033] Current methods to produce useful amounts of enzymes or other proteins, such as immunogenic proteins may often be expensive, time consuming and/or require expensive laboratory equipment and expertise. New methods may contribute to inexpensive or easy production of useful amounts of enzymes or other proteins, such as immunogenic proteins and/or reduced costs. Embodiments of the present disclosure provide a system and method that remains simple while achieving increased yields and/or final cell densities when compared to alternative systems.
[0034] When used herein, the following abbreviations and/or acronyms indicated the terms identified below:
[0035] ATCC refers to American Type Culture Collection;
[0036] CV, column volume;
[0037] DNAP, DNA polymerase;
[0038] ΔΔ, heat-treated protein sample;
[0039] EDTA, ethylenediamine tetraacetic acid;
[0040] LB, Luria-Bertani medium;
[0041] LdK39, Leishmania donovani kinesin 39;
[0042] OD 600 , optical density at 600 nm;
[0043] PAGE, polyacrylamide gel electrophoresis;
[0044] PCR, polymerase chain reaction;
[0045] PEI, polyethyleneimine;
[0046] PMSF, phenylmethane sulfonyl fluoride;
[0047] SDS, sodium dodecyl sulfate;
[0048] TBS, Terrific Broth plus Salts medium;
[0049] TCP, Total cell protein;
[0050] TRIS, tris hydroxymethylaminoethane; and
[0051] TYE, tryptone-yeast extract medium.
[0052] The present disclosure provides expression vectors and methods that may comprise the following characteristics: 1) chemical and/or temperature induction; 2) moderate to high cell density capability in shake-flasks; 3) host strain “portability;” and 4) high specific cell yield of one or more proteins that are being expressed. An expression vector of the disclosure may take advantage of the powerful rightward promoter from bacteriophage lambda cloned into a high copy-number plasmid, pUC19. This promoter/copy-number combination may provide high levels of transcription following induction. The promoter/gene transcriptional unit may be separated from the plasmid origin of replication by the T1T2 transcription terminators from the rrnB operon of E. coli thereby preventing post-induction transcription from interfering with plasmid replication/stability. Furthermore, transcription may be controlled by a modified lambda repressor “on-board” the plasmid allowing rapid screening of a variety of host strains to optimize expression yields, stability, and solubility of recombinant products. This repressor makes it possible to use either chemical or temperature induction or both in recA + strains which may be far more robust than typical recA − cloning hosts.
[0053] This disclosure describes methods using a plasmid, e.g. pcI ts ind + , to express a modified version of the large fragment of Taq DNA polymerase I, as a test enzyme, using all three modes of induction, chemical alone, temperature alone, and both, in shake-flasks routinely achieving final cell densities of 9 to 12 A 600 /ml and yields of purified enzyme in the range of 30 to 35 mg/liter of culture and 100 to 300 mg per batch. It should be noted, however, that persons having ordinary skill in the art will be able to apply the teachings of the present disclosure using additional test enzymes and with a wide range of results. One of skill in the art, in light of this disclosure, will also recognize that other promoters, origins of replication, transcription terminators, repressors, and the like may be used.
Examples
[0054] Some specific embodiments of the disclosure may be understood, by referring, at least in part, to the following examples. These examples are not intended to represent all aspects of the disclosure in its entirety. Variations will be apparent to one skilled in the art. The examples described herein may describe techniques, materials, processes and/or other concepts used in at least one example of practice of the teachings of the present disclosure, but should, however, not be construed to limit the scope of the those teachings.
Example 1
Materials and Methods
Materials
[0055] Bacteriophage lambda DNA, λcI857 ind 1 Sam7, pUC19 DNA, chemically competent E. coli C2984H cells (K12 F − proA + B + lacI q Δ (lac-proAB) glnV zgb-210::Tn10(Tet R ) endA1 thi-1 Δ(hsdS-mcrB)5 recA + ), and all restriction enzymes were obtained from New England Biolabs. DH5α (K12 F − 80ΔlacZ M15(lacZYA-argF) U169 recA endA1 hsdR17(r K12 − m K12 − ) phoA supE44 thi-1 gyrA96 relA1) chemically competent cells were purchased from Invitrogen. Thermus aquaticus YT-1 lyophilized cells (ATCC #25104) were obtained from the American Type Culture Collection and grown in Castenholtz 1% TYE medium at 70° C. Chromosomal DNA was isolated using the Genomic DNA Purification Protocol and columns from Qiagen Inc.
Culture Media
[0056] Transformed E. coli cells were grown in TBS medium or on LB plates at appropriate temperatures as are known in the art. Ampicillin (100 μg/ml) was added as required for ampicillin selection. Thermus aquaticus YT-1 cells were grown in Castenholtz 1% TYE plus vitamins and salts as described in the ATCC literature (recipe #461) with gentle shaking at 70° C.
Cloning Thermus Aquaticus DNA Polymerase I
[0057] The chromosomal DNA region spanning the DNA polymerase gene, Taq DNAP I, of Thermus aquaticus was isolated by PCR amplification using the DNAP I primers as shown in Table I and purified chromosomal DNA as template. The amplicon was cut with Bgl2 and Sph1 and subcloned into pUC19. The modified KlenTaq (“modKlenTaq1”) version of this polymerase gene was constructed by PCR amplification of the catalytic domain region using the modKlenTaq Primer and DNAP I Reverse Primer as shown in Table I. The forward primer adds an Nde1 site at the start of the coding region for the truncated version of the enzyme plus seven additional amino acids. The reverse primer adds an Sph1 site immediately adjacent to the stop codon. This amplicon was cut with Nde1 and Sph1 and subcloned into a modified pUC19 vector containing the T1T2 transcription terminator region from the rrnB operon of E. coli between the multi-cloning site and the origin of replication region in the plasmid. This formed the “base” plasmid which was used to construct the final expression vector by methods described below.
Expression Vector Construction
[0058] The region of the lambda genome containing the repressor gene, cI857 ind 1, and the rightward promoter, λP R , was isolated as a PCR amplicon spanning bases λ37151-λ38039 using the primers shown in Table I and purified lambda DNA as template. The reverse primer (λ37151) was designed to generate an Nde1 site at the original start codon for the λcro gene (“CAT ATG ”). The forward primer (λ38039) was designed to add a Kas1 site 3′ to the λcI857 ind 1 gene.
[0059] However, Kas1 digests of the amplicon generated a shorter than expected fragment indicating additional cutting within the coding region of the repressor gene. Therefore, the amplicon was cut with Mfe1 (originally at λ37186) plus Nde1 and subcloned into the “base” plasmid described above that was cut with EcoR1 and Nde1 generating pcI857 ts ind1-mKlenTaq1. The lambda repressor ind 1 mutation originally at position λ37589 was “back-mutated” to the wild-type sequence from T to C (with subsequent loss of the Hind3 site originally at λ37584) using site-directed mutagenesis forming the expression plasmid, pcI ts ind + modKlenTaqI as shown in FIG. 1 . This plasmid was then used for expression testing.
Expression Testing
[0060] The plasmid, pcI ts ind + modKlenTaqI, was transformed into chemically competent C2984H (recA + ) or DH5α (recA − ) cells, spread onto LB plus ampicillin plates, and incubated at 30° C. Ampicillin resistant colonies were selected and used to inoculate expression cultures in 75 ml TBS in 500-ml baffle-bottomed Erylenmeyer flasks shaken at 150 rpm at 30 or 32° C. When the cultures reached a cell density of 4 A 600 /ml, the cells were induced by one of three methods: 1) chemical-induction which was achieved, in one example, by addition of nalidixic acid to about 50 μg/ml; 2) temperature-induction which was achieved, in one example, by rapidly changing the temperature to 42° C. by swirling flasks in a water bath and maintaining for 20 minutes after which incubation was continued at 37° C.; or 3) by both chemical- and temperature-induction, which was achieved, in one example, by adding nalidixic acid to the culture and the temperature setting was increased to 37° C. from a starting temperature of 32° C. or 30° C.
Gel Samples
[0061] At appropriate times shown in the Figures, samples were removed from the cultures and placed on ice. Cells were pelleted at 6000×g for 5 minutes at room temperature. Cell pellets were resuspended in Lysis Buffer (50 mM TRIS, 2 mM EDTA, pH 8) plus lysozyme (0.5 mg/ml) and incubated at 37° C. for 10 minutes. Sodium chloride was added to the lysate to a final concentration of 500 mM to prevent the polymerase from binding to DNA in the pellets. After briefly sonicating the lysate to reduce viscosity, an aliquot was removed as the “Total Cell Protein Sample.” The remainder of the lysate was centrifuged at 13,000×g for 10 minutes at room temperature and an aliquot was removed from the supernatant to represent the “Soluble Protein Sample”. The remainder of the supernatant was heat treated at 75° C. for 45 minutes. Insoluble material was pelleted at 13,000×g for 5 minutes at room temperature and an aliquot was removed from the supernatant as the “Heat-treated Protein Sample.” Protein samples were analyzed by 8% SDS-PAGE. Protein concentrations were determined by Bradford assay (BioRad, Richmond, Calif.).
Large-Scale Cultures
[0062] Six 2.8-liter baffle-bottomed Fernbach flasks (Bellco BioTech) each containing 1.5-liters of TBS and ampicillin were used to grow C2984H cells transformed with pcI ts ind + modKlenTaqI at 30° C. with shaking at 150 rpm. When the cultures reach cell densities above 3 OD 600 /ml, the cultures were induced using temperature induction and chemical induction by either raising the shaker incubator temperature setting to 37° C. or by adding nalidixic acid to a final concentration of 50 mg/liter. Pre-induction and Harvest Samples were removed and processed as described above for SDS-PAGE. The cells were harvested at 24 hours post inoculation by centrifugation at 6,000×g for 20 minutes at 4° C. Cell pellets were weighed and stored at −20° C.
Purification
[0063] Frozen cell pastes were resuspended on ice in 5 volumes of Lysis Buffer (50 mM TRIS, 2 mM EDTA, 50 mM NaCl, 50 μM PMSF, pH 8) and lysozyme was added to 0.15 mg/ml. After 30 minutes, the lysate was sonicated to reduce viscosity. Sodium chloride was added to a final concentration of 0.25 M, and the sonicate was slowly added to an equal volume of Lysis Buffer in a water bath at 80° C. The temperature was kept above 60° C. during additions. After all the lysate was added, the mixture was incubated at 80° C. for an additional 45 minutes to precipitate host proteins. The heat treated lysate was cooled on ice and 10% polyethyleneimine was added to a final concentration of 0.3%. After 30 minutes, cell debris and denatured protein were pelleted at 10,000×g for 30 minutes at 4° C. The supernatant was diluted 3-fold with column buffer (20 mM TRIS, 1 mM EDTA, 0.05% TWEEN-20, 1% glycerol, pH 8.0) and loaded onto tandem BioRex-70 (2.6×20 cm) and Heparin-agarose (2.6×15 cm) columns. After washing with column buffer plus 100 mM NaCl until the OD 280 returned to background, modKlenTaq1 was eluted from the Heparin-agarose column using a 5.5 CV linear gradient (100 to 650 mM NaCl). The major peak eluting from the affinity column was modKlenTaq1 as shown in FIG. 7 . Each fraction was around 14 ml. Aliquots from the fractions were analyzed by 12% SDS-PAGE as shown in FIG. 8 . Peak fractions were pooled and flash frozen in liquid nitrogen, and stored at −80° C.
[0064] The examples resulting from at least one use of the process or materials described above were analyzed as described below. Although the results disclosed may be representative of the results expected when practicing the teachings disclosed herein, they should not be construed as limiting to the scope of the process. For instance, persons having ordinary skill in the art may be able to adjust process steps and/or constituents without departing from the scope of the present disclosure.
[0000] TABLE 1 Oligodeoxynucleotide Primers DNAP I Forward Primer gcatcagaagctcAGATCTacctgcctgag DNAP I Reverse Primer cagcaataGCATGCtcactccttggcggagagcca mod-KlenTaq Primer cgatgaCATATGggtaaacgtaaatctactgcctttctggagaggct lambda 37151 agctctaaGGCGGCggagtgaaaattcccctaattcgatgaagattct lambda 38039 ttgatacCATATG aacctccttagtacatgcaaccatt
Table 1 lists the primers used to construct and modify the expression plasmid, pcIts ind+ modKlenTaq1. Primers that have “cryptic” restriction sites to facilitate insertions are shown in CAPS. Underlined bases represent portions of coding regions for the genes indicated.
Example 2
Expression Plasmid Construction and Testing
[0065] The segment of phage lamdba genome spanning the λcI repressor, λO R and λP R region may be used for the design and construction of expression plasmids because it functions as a “self-contained” transcriptional control unit. The repressor protein may have very tight control over transcription from the rightward promoter. Using PCR primers containing cryptic restriction sites as shown in Table I and purified lambda DNA, an amplicon was generated that had modified ends for subcloning. By changing the bases just before the start codon of the λcro gene, a unique Nde1 site was introduced, which was used for the insertion of heterologous coding sequences.
[0066] FIG. 1 shows a partial restriction map for the plasmid, pcI ts ind + modKlenTaq1. The diagram shows the restriction sites used for the insertion of the modified KlenTaq I gene, mKlenTaq1, as well as transcription terminators, T1T2; the origin of replication, pUC19 ori; the β-lactamase gene, AMP; the lambda repressor, pcI ts ind + ; and, the rightward promoter, λP R . The map shows that there are two Hind3 sites but only one site (equivalent to λ37459) in the repressor gene because the ind 1 to ind + “back-mutation” eliminates the second site (equivalent to λ37589, T to C) that was originally in the λcI857 gene.
[0067] The transcriptional control unit consists of a fragment of the lambda genome spanning bases λ37187 to λ38043 as described above in Materials and Methods. The λcI857 ind 1 repressor originally has two Hind3 restriction sites at λ37584 and λ37459. The former site contains the ind 1 mutation that renders the repressor resistant to cleavage by RecA protein. Using site-directed mutagenesis, the final T of that Hind3 site was mutated to a C, eliminating the restriction site, and restoring sensitivity to RecA cleavage, the ind + phenotype.
[0068] FIG. 2 shows growth curves comparing the cell density of temperature-induced cells versus chemically-induced cells over time in accordance with teachings of the present disclosure. An overnight culture of C2984H cells transformed with pcI ts ind + modKlenTaqI was used to inoculate 225 ml TBS plus ampicillin (100 μg/ml) and grown at 32° C. (solid circles in FIG. 2 ). At a cell density of 4 OD 600 /ml (arrow), the culture was split into two subcultures: A) Chemical Induction Alone; solid squares (addition of nalidixic acid to 50 μg/ml and 30° C. for the duration of the experiment); and, B) Temperature Induction Alone; open circles (swirling in a 42° C. water bath for 20 minutes followed by incubation at 37° C. for the duration of the experiment).
[0069] C2984H cells transformed with pcI ts ind + modKlenTaq1 were used to test different modes of induction as shown in FIG. 2 . A 500-ml baffle-bottomed Erlenmeyer flask containing 225 ml of TBS plus ampicillin was inoculated from an overnight culture of C2984K[pcI ts ind + modKlenTaq1] and incubated at 32° C. with shaking at 150 rpm. When the cell density reached 4 OD 600 /ml, a Pre-induction Sample was removed and held on ice while the remainder of the culture was split into two subcultures, 100 ml each: 1) Chemical Induction Alone; and, 2) Temperature Induction Alone. In the case of the Chemical Induction Alone culture, nalidixic acid was added to a final concentration of 50 μg/ml and incubation was continued at 32° C. As a control, the Temperature Induction Alone culture was transferred to a 42° C. water bath, swirled for 20 minutes and then incubated at 37° C. with shaking for the duration of the experiment. This temperature induction regimen is used for lambda promoter-based expression plasmids under the control of a temperature sensitive lambda repressor. The cultures showed very similar growth curves. The nalidixic acid treated culture lagged behind the temperature induced culture. This may have been due to different incubation temperatures following induction. This may also be the result of induction of the SOS response by nalidixic acid. Nalidixic acid is a DNA gyrase inhibitor and the concentration used is sufficiently high to eventually inhibit chromosomal DNA replication.
[0070] FIG. 3 depicts a comparison of protein yields for temperature-induced cells and chemically-induced cells in accordance with some embodiments of the present disclosure. Samples were removed from the cultures described in FIG. 2 at the times indicated (“Pre”: just prior to induction; 1, 2, 4, and 22 hours post induction) and processed as described above in Materials and Methods. Aliquots from the heat-treated samples equivalent to 0.1 OD 600 units of cells were analyzed by 8% SDS PAGE. Arrows indicate the expected migration position for modKlenTaq1, ˜64,000 Da.
[0071] Samples were removed at the times indicated and processed as described above in Materials and Methods for analysis by 8% SDS-PAGE as shown in FIG. 3 . The gel shows only the heat treated samples for a comparison of the yields of modKlenTaq1. Each lane represents the protein from a cell sample equivalent to 0.1 OD 600 units. The banding patterns show that there was a low but detectable level of expression before induction. This may be due to partial inactivation of the repressor at 32° C. since subsequent experiments in which the cells were incubated at 30° C. showed no detectable expression in the pre-induction samples. Lambda expression systems generally have a single copy of the repressor as part of a pro-phage or cryptic lysogen. The results above indicate a higher concentration of repressor protein relative to other lambda expression systems even when the repressor gene was on-board the plasmid. This may be due to insufficient active repressor availability to fully inhibit transcription at 32° C.
[0072] The gel in FIG. 3 shows that the temperature-induction culture steadily accumulated modKlenTaq1 over the entire 26 hour time course of the experiment. Whereas, the chemically-induced culture showed slower accumulation with a maximum that occurred at 4 hours or at some time point between 4 and 26 hours since the 26 hour sample showed less staining than the 4 hour time point. Gels resolving the Total Cell Protein and Soluble Protein samples showed that modKlenTaq1 was only detected in the Total Cell Protein and Soluble Protein Samples and not lost to insoluble material (data not shown). Microscopic examination of the cells also indicated that the cells did not accumulate refractile bodies or become filamentous in either case following induction (data not shown). Since the repressor gene was present on the plasmid but there was only a single copy of the recA gene in the host chromosome, nalidixic acid induction alone may have been less efficient than temperature induction. Nevertheless, the 4 hour Chemical Induction Alone and the 4 hour Temperature Induction Alone samples are comparable.
[0073] FIG. 4 depicts protein yields for cells that were induced by both chemical and temperature methods in accordance with some embodiments of the present disclosure. C2984H cells transformed with pcI ts ind + modKlenTaq1 were grown in 100 ml of TBS plus ampicillin in a 500-ml baffle-bottomed Erlenmeyer flask at 32° C. with shaking at 150 rpm. When the cells reached a density of 4 OD 600 /ml the cultures were induced by adding nalidixic acid to a final concentration of 50 μg/ml as well as by increasing the incubator temperature to 37° C. Small shake-flasks under these conditions changed temperature from 32° C. to 37° C. Samples were removed at the times indicated and processed as described above in Materials and Methods and resolved on an 8% SDS-PAGE. Each lane represents the equivalent of 0.1 OD 600 of cells. FIG. 4 shows “TCP” (Total Cell Protein) and “ΔΔ” (Heat-treated Samples) for each of the time points. The arrow indicates the band for modKlenTaq.
[0074] FIG. 4 shows the effects to both adding nalidixic acid and simply increasing the incubator temperature dial to 37° C. The lanes represent the Total Cell Protein, “TCP,” and the Heat Treated Samples, “ΔΔ.” Following induction, the accumulation profile for modKlenTaq1 was comparable to that observed for the Temperature Alone experiments described above.
Example 3
Large Scale Shake Flask Cultures
[0075] FIG. 5 shows a growth curve for large-scale shake-flask expression using chemical- and temperature-induction in accordance with some embodiments of the present disclosure. One of six 2.8-liter baffle-bottomed Fernbach flasks each containing 1.5 liters of TBS plus ampicillin (100 μg/ml) was monitored for cell growth. Pre-induction growth was at 30° C. with shaking at 125 rpm. At an OD 600 /ml of 3, nalidixic acid was added to a final concentration of 50 μg/ml for chemical-induction and the temperature setting was increased to 37° C. for temperature-induction. The arrow indicates the time of induction. The final cell density was 11.2 OD 600 Units/ml; final cell wet weight was 96 gm.
[0076] FIG. 5 shows the growth curve for one of six identical 2.8-liter baffle-bottomed Fernbach flask cultures each containing 1.5 liters of TBS plus ampicillin and inoculated with C2984H cells carrying pcI ts ind + modKlenTaq1. The pre-induction incubation temperature was 30° C. to prevent pre-induction expression. One of the six flasks was used to monitor cell growth and to provide samples for gel analyses. The cells grew logarithmically up to a density of approximately 1.5 OD 600 /ml with a doubling time of about 50 minutes. At cell densities above 1.5 OD 600 /ml, in these large shake-flask cultures, the growth rate typically showed a steady decline. Smaller scale cultures using the same medium sustained logarithmic growth to a cell density above 8 OD 600 /ml. This may be an effect cells being starved for oxygen rather than of the medium being depleted of an essential nutrient. When the cell density reached 3 OD 600 /ml in the large shake-flasks (depicted by the arrow in FIG. 5 ), nalidixic acid was added to a final concentration of 50 μg/ml and the incubator temperature was increased to 37° C. The Lab-Line Model 3530-1 Orbital Shaker used in these experiments was able to increase the chamber temperature from 30° C. to 37° C. in 6 minutes. The temperature change within the flasks was much slower taking approximately 20 minutes. After 22 hours of incubation, the final cell density was 11.2 OD 600 /ml and the final cell yield was 96 gm wet weight. All six flasks showed comparable growth.
[0077] FIG. 6 depicts protein yields for large-scale shake-flask expression using temperature and chemical induction in accordance with some embodiments of the present disclosure. Samples were removed from the monitored flask described in FIG. 5 at the times indicated and processed as described above in Materials & Methods. Lanes 1-2: Pre-induction Total Cell Protein (TCP) and Heat-treated (ΔΔ); Lanes 3-4: 1 Hour TCP and ΔΔ; Lanes 5-6: 2 Hour TCP and ΔΔ; Lanes 7-8: 4 Hour TCP and ΔΔ; and, Lanes 9-10: 16.5 Hour TCP and ΔΔ. A sample equivalent 0.2 OD 600 /ml was loaded onto each lane on an 8% gel as in shown FIG. 3 . The arrow indicates modKlenTaq1 bands.
[0078] Samples were removed at the times indicated in FIG. 6 for gel analysis as described above. The gel shows Total Cell Protein and Heat-treated samples. Each lane was equivalent to 0.1 OD 600 units of cells. The gel shows no detectable accumulation of modKlenTaq1 in the pre-induction sample indicating more efficient control over transcription from the λP R promoter at 30° C. Accumulation of modKlenTaq1 was much slower in the large flasks compared to the rate of accumulation observed for the smaller-scale cultures, however, the final yield after 22 hours of incubation was comparable in terms of cell-specific yield and final cell density.
Example 4
Purification of modKlenTaq1
[0079] Thermus aquaticus DNA polymerase 1 is known to be a remarkably thermostable enzyme. Its large fragment has been shown to be extremely thermostable. A two-step rapid purification protocol is disclosed, the protocol may be scaled-up. Frozen cell pellets were resuspended in Lysis Buffer and treated with lysozyme followed by sonication on ice to shear the DNA and reduce viscosity. The sonicate was slowly poured into an equal volume of Lysis Buffer in a water bath maintained at 80° C. forming a stirred slurry. The temperature of the slurry was never allowed to fall below 60° C. to ensure immediate denaturation of host proteins, especially proteases. Upon addition of the entire sonicate, the slurry was incubated with stirring at 80° C. for an additional 45 minutes. Following incubation, the slurry was cooled, the salt concentration was increased, and PEI was added drop wise to precipitate DNA. High salt prevented modKlenTaq1 from binding to the DNA in the PEI-precipitate. After centrifugation, the supernatant was loaded onto two tandem columns: a weak cation exchanger, BioRad-70; followed by an affinity column, Heparin-sepharose. The cation exchanger acted as a pre-column for the Heparin-sepharose column removing excess PEI. After washing both columns in tandem until the OD 280 returned to baseline, the affinity column was isolated.
[0080] FIG. 7 shows an elution profile of the purification of modKlenTaq1 in accordance with some embodiments of the present disclosure. A sample equivalent to 48 gm of cell wet weight was processed as described above in Materials and Methods and following centrifugation, the supernatant was pumped directly onto tandem BioRex-70 and Heparin-sepharose columns. After washing until the OD 280 signal returned to baseline, a 100 to 650 mM NaCl-gradient was used to elute only the Heparin-sepharose column. ModKlenTaq1 eluted from the column at approximately 400 mM. Each column fraction was 14 ml. ModKlenTaq1 was eluted from the Heparin-sepharose column using a 5.5 CV linear gradient (100 mM to 650 mM NaCl) as shown in FIG. 7 .
[0081] FIG. 8 depicts gel analysis of the column fractions. Five μL aliquots from peak column fractions were analyzed by 12% SDS-PAGE. The arrow indicates the modKlenTaq1 band. The major peak was modKlenTaq1 as shown by gel analysis in FIG. 8 . The final yield of purified modKlenTaq1 was 285 mg.
[0000] modKlenTaq1 Expression Using Chemical vs. Temperature Induction
[0082] The lambda rightward promoter, λP R , is normally active during the lytic cycle of this temperate bacteriophage and is repressed during lysogeny. Efficient repression is necessary to maintain the lysogenic state and is provided by binding of the lambda repressor, λcI, to the λO R operator which, in turn represses the so-called anti-terminator gene, λcro. As long as the repressor concentration is moderately high, λcro remains repressed. Therefore, the region of the lamdba genome spanning the λcI repressor, λO R and λP R sequences is of special interest as a self-contained transcriptional control unit. The wild-type λcI repressor may be inactivated through self-proteolysis via a host encoded, activated RecA protein that acts as a co-protease. Treatment of E. coli with mitomycin-C or nalidixic acid induces recA expression and has been used to induce phage production from lysogens and to induce heterologous gene expression on plasmid constructs. For example, the leftward promoter has been used to overexpress the gene encoding transcription factor rho to very high levels using nalidixic acid for chemical-induced in recA + host cells that were also lambda cI + cryptic lysogens. Taq DNA polymerase has been expressed at 1-2% of the total cellular protein using a pPR-TGATG-1 expression vector with the temperature sensitive lambda repressor, λcI857, onboard the plasmid. Most expression vectors utilizing either of the lambda promoters, λP L or λP R or both, have been controlled by the temperature sensitive λcI857 repressor and unless the repressor is on-board the plasmid are limited to lysogenic hosts. The λcI857 repressor carries two mutations, temperature sensitivity (A67T) and ind 1 (E118K) or resistance to RecA protein cleavage. An expression system that relies on the λcI857 repressor may be induced using temperature.
[0083] Raising the temperature of several flasks rapidly has been a problem using shake-flask cultures. The teachings of the present disclosure, in some embodiments, provide a novel expression construct that comprises a lambda repressor gene, λcI ts ind + , that provides for temperature and/or chemical induction. As shown in FIG. 1 , the expression vector, pcI ts ind + , comprises a region from lambda, λcI857 ind 1 Sam7, that includes the λcI857 ind 1 repressor, the λP R promoter and the start codon of the λcro gene. In some embodiments, the repressor may be back-mutated to be ind + while maintaining the temperature sensitive phenotype. Restoring ind + may remove a Hind3 restriction site (T to C at λ37589) thereby enabling a method to identify back-mutation clones. In some embodiments, the coding region for the λcro gene may be deleted and a unique Nde1 insertion restriction site constructed to overlap its ATG initiation codon. This construction may add an additional base and change a base in the sequence between the Shine-Dalgarno site and the initiator codon ( . . . AGGAGGTTGT-ATG . . . to . . . AGGAGGTTcaT-ATG . . . ).
[0084] Despite the high percentage of GC content of the coding sequence for modKlenTaq1, it may not be necessary to use a “stutter-stop-start” pre-coding segment to avoid secondary structure in the mRNA. In some embodiments, the coding sequence for modKlenTaq1 may be linked directly to the ATG start codon at the Nde1 site described above. In some embodiments, a unique Sph1 3′-insertion restriction site may be constructed immediately ahead of the T1T2 ribosomal terminators from the E. coli rrnB operon in the plasmid pUC19-T1T2. This plasmid has as its origin of replication the high copy number pUC ori. In some embodiments, a portion of the Taq DNA polymerase 1 gene may be amplified using PCR primers containing the same cryptic restriction sites to allow insertion of the modKlenTaq 1 coding region into the Nde1 and Sph1 sites as shown in FIG. 1 generating the plasmid, pcI ts ind + modKlenTaq1. This version of the Taq DNAP1 gene encodes the C-terminal amino acids 281-832 plus 7 additional amino acids added at its N-terminal end for improved solubility, MGKRKST.
[0085] In some embodiments, the expression plasmid, pcI ts ind + modKlenTaq1, may be transformed into C2984H cells (recA + ). recA + hosts may be far more robust than recA − hosts that may be used for expression of recombinant enzymes. C2984H grown at 30° C. showed doubling times as short as recA − strains like DH5α cells grown at 37° C.
[0086] For example, small volume cultures were used to survey the effects of temperature- vs. chemical-induction. FIG. 2 shows that the growth curves for either type of induction were similar. FIG. 3 shows a gel for the heat-treated samples removed at the various times as indicated from each culture. In initial experiments, the pre-induction incubation temperature was 32° C. and a low level of expression was observed in the pre-induction samples. All large scale experiments described herein were conducted at a pre-induction temperature of 30° C. and no pre-induction expression was detected. FIG. 3 shows that both induction schemes were successful in expressing modKlenTaq1. In some embodiments, temperature-induction alone was more efficient than chemical-induction alone with respect to the accumulation rate and final overall specific cell yield of modKlenTaq1 as observed from the about 2 to 3-fold darker staining bands for all samples taken from the temperature-induced culture. A temperature shift may inactivate all repressor molecules at the time of induction. The presence of a single copy of the recA gene in the host chromosome relative to the lambda repressor present on a high copy number plasmid, may result in low level of expression of RecA as compared to the level of repressor molecules in the cell. In some embodiments, continued incubation at lower temperatures following the addition of nalidixic acid may allow continued expression of active repressor. In some embodiments, chemical-induction induced modKlenTaq1 to high specific cell yields and the 4 hour time points were comparable.
[0087] In some embodiments, combined induction may be more efficient as accumulation of modKlenTaq1 in chemically-induced cultures lagged behind the rate observed for temperature-induced cultures (where levels of RecA protein were overwhelmed by repressor concentrations and by continued synthesis of active repressor). FIG. 4 shows the Total Cell Protein and Heat-treated Protein samples for a small scale culture that was induced by the addition of nalidixic acid and increasing the incubator temperature to 37° C. The accumulation and final specific cell yield of modKlenTaq1 were comparable to the results shown in FIG. 3 for the Temperature Induction Alone culture. Increased temperature (37° C. following the addition of nalidixic acid) reduces the number of active repressor molecules that were cleaved by RecA protein. In some embodiments, the disclosure provides a scaled-up method for producing larger quantities of the protein using the expression vector of the disclosure comprising a) addition of nalidixic acid; and b) raising the incubator temperature, suing more than one shake-flasks with larger volumes. In some embodiments, the method may involve a “temperature-jump” to 42° C. In some embodiments, the scaled-up method for production is easier to perform than the temperature jump method.
Example 5
Large-Scale Shake-Flask Expression Using Both Chemical and Temperature Induction
[0088] FIG. 5 shows a growth curve for one of 6 flasks (each 1.5 liters of TB with Salts and Ampicillin). The pre-induction incubation temperature was 30° C. The cells showed a doubling time of approximately 50 minutes during log phase growth up to a density of about 2 OD 600 /m. Unlike the small volume cultures, the larger volume flasks showed decreasing growth rates above a cell density of 2 A 600 /ml. Since the smaller volume cultures were able to sustain logarithmic growth to a cell density above 8 A 600 /ml as shown in FIG. 2 , the decreasing growth rate may be due to the larger volume flasks being less efficient at air exchange rather than the cultures being depleted of an essential nutrient. As the growth rate showed a steady decline at cell densities above 2 OD 600 /ml, induction was performed earlier. At a cell density of 3 OD 600 /ml, nalidixic acid was added to a final concentration of 50 μg/ml and the temperature controller on the shaker incubator was raised to 37° C. Samples were removed and processed as described at the times indicated in FIG. 6 . The final cell density after 22 hours of growth (16.5 hours elapsed time from the time of induction) reached 11.2 A 600 /ml yielding 96 gm total cell wet weight or 10.6 gm/liter. Samples were processed for Total Cell Protein and Heat Treated Supernatant. ModKlenTaq1 was not detectable before induction. Post induction, modKlenTaq1 appeared at 2 hours and steadily increased for the duration of the experiment as shown in both the Total Cell Protein and Heat Treated fractions.
Example 6
Purification of modKlenTaq1
[0089] Taq DNA polymerase is a thermostable enzyme and has been shown to have a half-life in excess of 60 minutes at 95° C. The present disclosure provides a rapid two-step purification protocol including a heat-treatment step plus affinity chromatography to purify modKlenTaq1. The cell lysate was incubated at 80° C. for 45 minutes to precipitate most E. coli proteins. DNA was removed by precipitation with polyethyleneimine and the resulting supernatant after pelleting cell debris and denatured proteins was pumped directly onto two columns in tandem: the first column was a weak-cation exchanger to remove excess polyethyleneimine (BioRex-70) and the second column was an affinity column, Heparin-sepharose. ModKlenTaq1 bound tightly to the affinity column, eluting at 0.4 M NaCl as the major peak with a small shoulder representing a faster migrating species on SDS-PAGE. The final total yield of purified modKlenTaq1 was 285 mg from 9 liters of culture in 6 flasks or 31.6 mg/L or 3 mg/gm cell wet weight.
[0090] One example of a plasmid sequence as described above is as follows:
[0000]
(SEQ ID NO: 1)
1
CATATGGGTA AACGTAAATC TACTGCCTTT CTGGAGAGGC TTGAGTTTGG
51
CAGCCTCCTC CACGAGTTCG GCCTTCTGGA AAGCCCCAAG GCCCTGGAGG
101
AGGCCCCCTG GCCCCCGCCG GAAGGGGCCT TCGTGGGCTT TGTGCTTTCC
151
CGCAAGGAGC CCATGTGGGC CGATCTTCTG GCCCTGGCCG CCGCCAGGGG
201
GGGCCGGGTC CACCGGGCCC CCGAGCCTTA TAAAGCCCTC AGGGACCTGA
251
AGGAGGCGCG GGGGCTTCTC GCCAAAGACC TGAGCGTTCT GGCCCTGAGG
301
GAAGGCCTTG GCCTCCCGCC CGGCGACGAC CCCATGCTCC TCGCCTACCT
351
CCTGGACCCT TCCAACACCA CCCCCGAGGG GGTGGCCCGG CGCTACGGCG
401
GGGAGTGGAC GGAGGAGGCG GGGGAGCGGG CCGCCCTTTC CGAGAGGCTC
451
TTCGCCAACC TGTGGGGGAG GCTTGAGGGG GAGGAGAGGC TCCTTTGGCT
501
TTACCGGGAG GTGGAGAGGC CCCTTTCCGC TGTCCTGGCC CACATGGAGG
551
CCACGGGGGT GCGCCTGGAC GTGGCCTATC TCAGGGCCTT GTCCCTGGAG
601
GTGGCCGAGG AGATCGCCCG CCTCGAGGCC GAGGTCTTCC GCCTGGCCGG
651
CCACCCCTTC AACCTCAACT CCCGGGACCA GCTGGAAAGG GTCCTCTTTG
701
ACGAGCTAGG GCTTCCCGCC ATCGGCAAGA CGGAGAAGAC CGGCAAGCGC
751
TCCACCAGCG CCGCCGTCCT GGAGGCCCTC CGCGAGGCCC ACCCCATCGT
801
GGAGAAGATC CTGCAGTACC GGGAGCTCAC CAAGCTGAAG AGCACCTACA
851
TTGACCCCTT GCCGGACCTC ATCCACCCCA GGACGGGCCG CCTCCACACC
901
CGCTTCAACC AGACGGCCAC GGCCACGGGC AGGCTAAGTA GCTCCGATCC
951
CAACCTCCAG AACATCCCCG TCCGCACCCC GCTTGGGCAG AGGATCCGCC
1001
GGGCCTTCAT CGCCGAGGAG GGGTGGCTAT TGGTGGCCCT GGACTATAGC
1051
CAGATAGAGC TCAGGGTGCT GGCCCACCTC TCCGGCGACG AGAACCTGAT
1101
CCGGGTCTTC CAGGAGGGGC GGGACATCCA CACGGAGACC GCCAGCTGGA
1151
TGTTCGGCGT CCCCCGGGAG GCCGTGGACC CCCTGATGCG CCGGGCGGCC
1201
AAGACCATCA ACTTCGGGGT CCTCTACGGC ATGTCGGCCC ACCGCCTCTC
1251
CCAGGAGCTA GCCATCCCTT ACGAGGAGGC CCAGGCCTTC ATTGAGCGCT
1301
ACTTTCAGAG CTTCCCCAAG GTGCGGGCCT GGATTGAGAA GACCCTGGAG
1351
GAGGGCAGGA GGCGGGGGTA CGTGGAGACC CTCTTCGGCC GCCGCCGCTA
1401
CGTGCCAGAC CTAGAGGCCC GGGTGAAGAG CGTGCGGGAG GCGGCCGAGC
1451
GCATGGCCTT CAACATGCCC GTCCAGGGCA CCGCCGCCGA CCTCATGAAG
1501
CTGGCTATGG TGAAGCTCTT CCCCAGGCTG GAGGAAATGG GGGCCAGGAT
1551
GCTCCTTCAG GTCCACGACG AGCTGGTCCT CGAGGCCCCA AAAGAGAGGG
1601
CGGAGGCCGT GGCCCGGCTG GCCAAGGAGG TCATGGAGGG GGTGTATCCC
1651
CTGGCCGTGC CCCTGGAGGT GGAGGTGGGG ATAGGGGAGG ACTGGCTCTC
1701
CGCCAAGGAG TGAGCATGCA GTAGGGAACT GCCAGGCATC AAATAAAACG
1751
AAAGGCTCAG TCGAAAGACT GGGCCTTTCG TTTTATCTGT TGTTTGTCGG
1801
TGAACGCTCT CCTGAGTAGG ACAAATCCGC CGGGAGCGGA TTTGAACGTT
1851
GCGAAGCAAC GGCCCGGAGG GTGGCGGGCA GGACGCCCGC CATAAACTGC
1901
CAGGCATCAA ATTAAGCAGA AGGCCATCCT GACGGATGGC CTTTTTGCGT
1951
TTCTACAAAC TCTTTTTGTT TATTTTTCTA AATACATTCA AATATGTATC
2001
CGCTCATGAG ACAATAGATC TAAGCTTGGC GTAATCATGG TCATAGCTGT
2051
TTCCTGTGTG AAATTGTTAT CCGCTCACAA TTCCACACAA CATACGAGCC
2101
GGAAGCATAA AGTGTAAAGC CTGGGGTGCC TAATGAGTGA GCTAACTCAC
2151
ATTAATTGCG TTGCGCTCAC TGCCCGCTTT CCAGTCGGGA AACCTGTCGT
2201
GCCAGCTGCA TTAATGAATC GGCCAACGCG CGGGGAGAGG CGGTTTGCGT
2251
ATTGGGCGCT CTTCCGCTTC CTCGCTCACT GACTCGCTGC GCTCGGTCGT
2301
TCGGCTGCGG CGAGCGGTAT CAGCTCACTC AAAGGCGGTA ATACGGTTAT
2351
CCACAGAATC AGGGGATAAC GCAGGAAAGA ACATGTGAGC AAAAGGCCAG
2401
CAAAAGGCCA GGAACCGTAA AAAGGCCGCG TTGCTGGCGT TTTTCCATAG
2451
GCTCCGCCCC CCTGACGAGC ATCACAAAAA TCGACGCTCA AGTCAGAGGT
2501
GGCGAAACCC GACAGGACTA TAAAGATACC AGGCGTTTCC CCCTGGAAGC
2551
TCCCTCGTGC GCTCTCCTGT TCCGACCCTG CCGCTTACCG GATACCTGTC
2601
CGCCTTTCTC CCTTCGGGAA GCGTGGCGCT TTCTCATAGC TCACGCTGTA
2651
GGTATCTCAG TTCGGTGTAG GTCGTTCGCT CCAAGCTGGG CTGTGTGCAC
2701
GAACCCCCCG TTCAGCCCGA CCGCTGCGCC TTATCCGGTA ACTATCGTCT
2751
TGAGTCCAAC CCGGTAAGAC ACGACTTATC GCCACTGGCA GCAGCCACTG
2801
GTAACAGGAT TAGCAGAGCG AGGTATGTAG GCGGTGCTAC AGAGTTCTTG
2851
AAGTGGTGGC CTAACTACGG CTACACTAGA AGAACAGTAT TTGGTATCTG
2901
CGCTCTGCTG AAGCCAGTTA CCTTCGGAAA AAGAGTTGGT AGCTCTTGAT
2951
CCGGCAAACA AACCACCGCT GGTAGCGGTG GTTTTTTTGT TTGCAAGCAG
3001
CAGATTACGC GCAGAAAAAA AGGATCTCAA GAAGATCCTT TGATCTTTTC
3051
TACGGGGTCT GACGCTCAGT GGAACGAAAA CTCACGTTAA GGGATTTTGG
3101
TCATGAGATT ATCAAAAAGG ATCTTCACCT AGATCCTTTT AAATTAAAAA
3151
TGAAGTTTTA AATCAATCTA AAGTATATAT GAGTAAACTT GGTCTGACAG
3201
TTACCAATGC TTAATCAGTG AGGCACCTAT CTCAGCGATC TGTCTATTTC
3251
GTTCATCCAT AGTTGCCTGA CTCCCCGTCG TGTAGATAAC TACGATACGG
3301
GAGGGCTTAC CATCTGGCCC CAGTGCTGCA ATGATACCGC GAGACCCACG
3351
CTCACCGGCT CCAGATTTAT CAGCAATAAA CCAGCCAGCC GGAAGGGCCG
3401
AGCGCAGAAG TGGTCCTGCA ACTTTATCCG CCTCCATCCA GTCTATTAAT
3451
TGTTGCCGGG AAGCTAGAGT AAGTAGTTCG CCAGTTAATA GTTTGCGCAA
3501
CGTTGTTGCC ATTGCTACAG GCATCGTGGT GTCACGCTCG TCGTTTGGTA
3551
TGGCTTCATT CAGCTCCGGT TCCCAACGAT CAAGGCGAGT TACATGATCC
3601
CCCATGTTGT GCAAAAAAGC GGTTAGCTCC TTCGGTCCTC CGATCGTTGT
3651
CAGAAGTAAG TTGGCCGCAG TGTTATCACT CATGGTTATG GCAGCACTGC
3701
ATAATTCTCT TACTGTCATG CCATCCGTAA GATGCTTTTC TGTGACTGGT
3751
GAGTACTCAA CCAAGTCATT CTGAGAATAG TGTATGCGGC GACCGAGTTG
3801
CTCTTGCCCG GCGTCAACAC GGGATAATAC CGCGCCACAT AGCAGAACTT
3851
TAAAAGTGCT CATCATTGGA AAACGTTCTT CGGGGCGAAA ACTCTCAAGG
3901
ATCTTACCGC TGTTGAGATC CAGTTCGATG TAACCCACTC GTGCACCCAA
3951
CTGATCTTCA GCATCTTTTA CTTTCACCAG CGTTTCTGGG TGAGCAAAAA
4001
CAGGAAGGCA AAATGCCGCA AAAAAGGGAA TAAGGGCGAC ACGGAAATGT
4051
TGAATACTCA TACTCTTCCT TTTTCAATAT TATGTAAGCA GACAGTTTTA
4101
TTGTTCATGA TGATATATTT TTATCTTGTG CAATGTAACA TCAGAGATTT
4151
TGAGACACAA CGTGGCTTTG TTGAATAAAT CGAACTTTTG CTGAGTTGAC
4201
TCCCCGCGCG GACATTAATT GCGTTGCGCT CACTGCCCGC TTTCCAGTCG
4251
GGAAACCTGT CGTGCCAGCT GCATTAATGA ATCGGCCAAC GCGCGGGGAG
4301
AGGCGGTTTG CGTATTGGGC GCCATAGACG TCTTTGAATT GTTATCAGCT
4351
ATGCGCCGAC CAGAACACCT TGCCGATCAG CCAAACGTCT CTTCAGGCCA
4401
CTGACTAGCG ATAACTTTCC CCACAACGGA ACAACTCTCA TTGCATGGGA
4451
TCATTGGGTA CTGTGGGTTT AGTGGTTGTA AAAACACCTG ACCGCTATCC
4501
CTGATCAGTT TCTTGAAGGT AAACTCATCA CCCCCAAGTC TGGCTATGCA
4551
GAAATCACCT GGCTCAACAG CCTGCTCAGG GTCAACGAGA ATTAACATTC
4601
CGTCAGGAAA GCTTGGCTTG GAGCCTGTTG GTGCGGTCAT GGAATTACCT
4651
TCAACCTCAA GCCAGAATGC AGAATCACTG GCTTTTTTGG TTGTGCTTAC
4701
CCATCTCTCC GCATCACCTT TGGTAAAGGT TCTAAGCTCA GGTGAGAACA
4751
TCCCTGCCTG AACATGAGAA AAAACAGGGT ACTCATACTC ACTTCTAAGT
4801
GACGGCTGCA TACTAACCGC TTCATACATC TCGTAGATTT CTCTGGCGAT
4851
TGAAGGGCTA AATTCTTCAA CGCTAACTTT GAGAATTTTT GTAAGCAATG
4901
CGGCGTTATA AGCATTTAAT GCATTGATGC CATTAAATAA AGCACCAACG
4951
CCTGACTGCC CCATCCCCAT CTTGTCTGCG ACAGATTCCT GGGATAAGCC
5001
AAGTTCATTT TTCTTTTTTT CATAAATTGC TTTAAGGCGA CGTGCGTCCT
5051
CAAGCTGCTC TTGTGTTAAT GGTTTCTTTT TTGTGCTCAT ACGTTAAATC
5101
TATCACCGCA AGGGATAAAT ATCTAACACC GTGCGTGTTG ACTATTTTAC
5151
CTCTGGCGGT GATAATGGTT GCATGTACTA AGGAGGTT
Example 7
Construction of LdK39 Vector
[0091] FIG. 10 depicts a partial restriction map of the LdK39 gene. A nucleic acid containing the LdK39 gene was cut with the restriction enzymes Nde1 and Sph1 to yield a fragment. This fragment was subcloned into pUC19. This formed a base plasmid from which a final expression vector was prepared.
[0092] The final expression vector was prepared as shown in FIG. 11 . The pUC19 vector containing the LdK39 gene fragment was cut with Nde1 and Sph1 to free the LdK39 fragment. This fragment was then subcloned into Nde1 and Sph1 cut fragment of the pcl ts Taq G46D W645C vector. The resulting final vector contained an LdK39 fragment able to code a 745 amino acid protein in a pcl ts ind + vector.
Example 8
Expression Testing
[0093] C2984H cells were transformed with the pcl ts ind + LdK39-745 vector of Example 7. A 500-ml baffle-bottomed Erlenmeyer flask containing 125 mL of TBS plus ampicillin was inoculated from an overnight culture of C2984H[pcl ts ind + LdK39-745] and incubated at 30° C. with shaking at 150 rmp. When cell density reached 4 OD 600 /mL, a Pre-induction sample was removed and held on ice while the remainder of the culture was split into two subcultures, 60 mL each: 1) Chemical Induction Alone; and 2) Temperature and Chemical Induction. In the case of both samples, nalidixic acid was added to a final concentration of 50 μg/mL. For the Chemical Induction Alone sample, incubation was continued at 30° C. For the Temperature and Chemical Induction sample, the culture was transferred to a 42° C. water bath, swirled for 20 minutes, and then incubated at 37° C. with shaking for the duration of the experiment. Samples were taken from both cultures 1, 2, 4 and 26 hours post-induction
[0094] FIG. 12 shows growth curves for these samples. The final OD/mL for the Chemical Induction Only sample was 7. The final OD/mL for the Temperature and Chemical Induction sample was 8.9.
[0095] FIG. 13 depicts a comparison of protein yields for the two samples at the times tested. Samples were processed as described in Example 1. Aliquots from each sample equivalent to 0.1 OD 600 units of cells were analyzed by 8% SDS PAGE. Arrows indicate the expected migration position for the 745 amino acid LdK39 protein.
[0096] The pcl ts ind + LdK39-745 vector was modified to add a Flag-tag to the LdK39 protein. C2984H cells were transformed with this modified vector and grown as described previously in this example. The cells were subject to both chemical and temperature induction. Cell protein was extracted as described in the “Gel Samples” portion of Example 1. Samples representing total cell protein, soluble protein, and insoluble protein were prepared. The samples were also eluted through an affinity column as described in Example 1. Both the cell protein and affinity column samples were used to prepare a Western blot that was then probed with an anti-Flag antibody (Sigma, St. Louis, Mo.). Flag-tagged LdK745 was clearly identified in the samples that had been induced and was absent in the pre-induction samples.
[0097] Thus, the pcl ts ind + LdK39-745 vector or similar vectors containing LdK fragments may be used for high-yield production of LdK protein or protein fragments. These LdK proteins or protein fragments may be immunogenic and may be useful in inducing a protective immune response.
[0098] As will be understood by those skilled in the art, other equivalent or alternative methods, devices, systems and compositions for generating workable amounts of enzymes according to embodiments of the present disclosure may be envisioned without departing from the essential characteristics thereof. For example, where a range is disclosed, the end points may be regarded as guides rather than strict limits. In some embodiments, methods, compositions, devices, and/or systems may be adapted to accommodate ergonomic interests, aesthetic interests, scale, or any other interests. Such modifications may influence other steps, structures and/or functions (e.g., positively, negatively, or insubstantially). A negative influence on function may include, for example, a loss of fractionation capacity and/or resolution. Yet, this loss may be deemed acceptable, for example, in view of offsetting ergonomic, aesthetic, scale, cost, or other factors.
[0099] In some embodiments, a device of the disclosure may be manufactured in either a handheld or a tabletop configuration, and may be operated sporadically, intermittently, and/or continuously. Individuals skilled in the art would recognize that additional separation methods may be incorporated, e.g., to partially or completely remove proteins, lipids, carbohydrates, nucleic acids, salts, solvents, detergents, and/or other materials from a test sample. Also, the temperature (e.g. incubation temperature or induction temperature), pressure, and acceleration at which each step is performed may be varied.
[0100] All or part of a system of the disclosure may be configured to be disposable and/or reusable. From time to time, it may be desirable to clean, repair, and/or refurbish at least a portion of a device and/or system of the disclosure. For example, a reusable component may be cleaned to inactivate, remove, and/or destroy one or more contaminants. Individuals skilled in the art would recognize that a cleaned, repaired, and/or refurbished component is within the scope of the disclosure.
[0101] These equivalents and alternatives along with obvious changes and modifications are intended to be included within the scope of the present disclosure. Moreover, one of ordinary skill in the art will appreciate that no embodiment, use, and/or advantage is intended to universally control or exclude other embodiments, uses, and/or advantages. Expressions of certainty (e.g., “will,” “are,” and “can not”) may refer to one or a few example embodiments without necessarily referring to all embodiments of the disclosure. Accordingly, the foregoing disclosure is intended to be illustrative, but not limiting, of the scope of the disclosure.
REFERENCES
[0102] The following references, to the extent that they provide exemplary procedural or other details supplementary to those set forth herein, are specifically incorporated herein, in their entirety, by reference:
[0103] A. Villaverde, A. Benito, E. Viaplana, R. Cubarsi. Fine regulation of cI857-controlled gene expression in continuous culture of recombinant Escherichia coli by temperature. Appl. Environ. Microbiol. 59 (1993) 3485-3487.
[0104] A. Dey, P. Sharma, N. S. Redhu, S. Singh. Kinesin Motor Domain of Leishmania Donovani as future vaccine candidate. Clin. Vaccine Immunology, online pre-publication, Mar. 19, 2008.
[0105] C. Yanish-Perron, J. Vieira, J. Messing. Improved M13 phage and host strains: nucleotide sequences of the M13mp18 and pUC19 vectors. Gene 33 (1985) 103-119.
[0106] D. R. Engleke, A. Krikos, M. E. Bruck, D. Ginsburg. Purification of Thermus aquaticus DNA polymerase expressed in E. coli. Analyt. Biochem. 191 (1990): 396-400.
[0107] E. Remaut, P. Stanssens, W. Fiers. Plasmid vectors for high-efficiency expression controlled by the PL promoter of coliphage lambda. Gene 15 (1981) 81-93.
[0108] F. Baneyx. Recombinant protein expression in Escherichia coli. Curr. Opin. Biotechnol. 10 (1999) 411-421.
[0109] J. Brosius, A. Ulrich, M. A. Baker, A. Gray, T. J. Dull, R. G. Gutell, H. F. Noller. Construction and fine mapping of recombinant plasmids containing the rrnB ribosomal RNA operon of E. coli. Plasmid 6 (1981) 112-118.
[0110] J. A. Mustard, J. W. Little. Analysis of Escherichia coli recA interactions with lexA. λcI, and ummD by site-directed mutagenesis of recA. J. Bacteriol. 182 (2000) 1659-1670.
[0111] J. E. Mott, R. A. Grant, Y.-S. Ho, T. Platt. Maximizing gene expression from plasmid vectors containing the λP L promoter: Strategies for over producing transcription terminator factor ρ. Proc. Natl. Acad. Sci. USA 82 (1985) 88-92.
[0112] J. H. Miller. Experiments in Molecular Genetics. (1972) Cold Spring Harbor Laboratory Press, NY.
[0113] J. W. Roberts and R. Devoret (1983) in Lambda II, Hendrix, R., Roberts, J., Stahl, F., and Weisberg, R., eds. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., pp. 130-133.
[0114] K. A. Johnson. Rapid quench kinetic analysis of polymerases, adenosinetriphosphatases, and enzyme intermediates. Methods in Enzymol. 249 (1995) 38-61.
[0115] K. D. Tartoff, C. A. Hobbs. Improved media for growing plasmid and cosmid clones. Bethesda Research Labs Focus 9 (1987) 12.
[0116] L. I. Patrushev, A. G. Valiaev, P. A. Golovchenko, S. V. Vinogradov, M. L. Chikindas, V. I. Kieselev. Cloning of the gene for thermostable Thermus aquaticus YT-1 DNA polymerase and its expression in Escherichia coli. Mol. Biol. (Mosk) 27 (1993) 1100-1112.
[0117] N. Gerald, I. Coppens, D. Dwyer. Molecular dissection and expression of the LdK39 kinesin in the human pathogen, Leishmania donovani. Molec. Microbio. 63 (4) (2007) 962-979.
[0118] S. Korolev, N. Murad, W. M. Barnes, E. DiCera, G. Waksman. Crystal structure of the large fragment of Thermus aquaticus DNA polymerase 1 at 2.5 A: Structural basis for thermostability. Proc. Natl. Acad. Sci. USA 92 (1995) 9264-9268.
[0119] S. C. Makrides. Strategies for achieving high-level expression of genes in Escherichia coli. Microbiol. Rev. 60 (1996) 512-538.
[0120] T. D. Brock, H. Freeze. Thermus aquaticus gen. n. and sp. n., a non-sporulating extreme thermophile. J. Bacteriol. 98 (1969) 289-297.
[0121] U. K. Laemmli. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227 (1970) 680-685.
[0122] W. M. Barnes. The fidelity of Taq polymerase catalyzing PCR is improved by an N-terminal deletion. Gene 112 (1992) 29-35.
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The present disclosure relates to nucleic acids comprising a sequence of SEQ ID NO: 1. The nucleic acid may be an isolated DNA and/or may be in the form of a plasmid or an expression vector. It may also be comprised in a microorganism. The nucleic acid may further comprise sequences that encode a protein. The self-replicating expression plasmid comprising a DNA sequence of the disclosure may be used to produce one or more protein. The production of one or more protein by a plasmid of the disclosure may be controlled by temperature and/or chemical induction. The disclosure also provides methods of obtaining high yields of proteins and methods for purifying such proteins, such as the LdK39 protein or a fragment thereof.
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FIELD OF THE INVENTION
The invention relates generally to work vehicles such as tractors. More particularly, it relates to vehicle mounts or hitches for hitching other devices to such work vehicles.
BACKGROUND OF THE INVENTION
Vehicles such as tractors often need to be attached to implements. The implements may be towed on their own wheels or may be mounted in a fixed manner to the rear of the chassis or frame of the tractor. The former include wagons, carts, material spreaders, mowers and the like. The latter include pavement breakers, backhoe attachments, grading blades, ground breakers and plows, among other devices.
These different implements are affixed to the vehicle in different ways depending upon the desired flexibility and rigidity of the coupling between them. For a relatively rigid connection, such as for implements like plows or cultivators that need to be raised and lowered with some regularity, the chassis of frame of the vehicle is coupled to a three-point hitch assembly, which often includes an adjuster such as an adjustable eye or a hydraulic actuator that permit the hitch to be raised and lowered with respect to the vehicle's chassis.
Other implements such as wagons and carts can be coupled to the tractor simply by providing a bracket (or “drawbar”) with a hole through which a pin can be inserted. These couplings are used to connect the tongues of wagons or other vehicles that do not need the vertical or lateral support of the rigid frame or chassis of the tractor.
These two couplings—the drawbar and the three-point hitch, are the generic couplings provided on most modern tractors. This is not to say, however, that the rear structures of the chassis or frame to which these are mounted are the same. Each tractor may be manufactured differently, and may have different and unique structures at the rear of the chassis or frame. Nonetheless, the vast majority include brackets or linkages affixed to the chassis or frame that provide the three point arrangement or have a drawbar receiving aperture.
Many tractors, due to the specialized uses for which they are sold, do not come equipped with a three-point hitch assembly mounted onto the chassis or frame. These tractors are often too small in practice to pull the kind of implements (plow, cultivator, etc) that are fixed to three point hitches. Furthermore, they are often bought with other specialized applications in mind that do not couple to a three point hitch. Examples include ditch digging attachments, backhoe attachments, pavement breaking attachments, pavement cutting attachments, road grading attachments and the like.
One difficulty with such vehicles is the lack of a standard hitching structure that a variety of these specialized attachments or implements can be fixed to. The traditional three point hitch is large and often unwieldy on such small tractors, and a simple means of towing the implement, while necessary, is not enough to support the implement.
Several systems for attaching an implement to a vehicle are worth mentioning.
U.S. Pat. No. 5,779,429 illustrates a system for quickly attaching an implement to a tractor. This device includes an elongated rectangular channel to which four hooks extend upward. The device is fixed to the tractor and the implement rests on the four upwardly extending hooks.
U.S. Pat. No. 3,876,092 illustrates an implement connecting coupler mechanism that is structured generally as a four bar linkage having one bar coupled to the frame of the tractor and the opposing bar of the linkage configured to be rapidly connected to an implement. A hydraulic cylinder is coupled to and extends between the two links to permit the implement link to be raised and lowered with respect to the tractor.
U.S. Pat. No. 3,912,092 is directed to a tractor lift, including a tubular framework that is coupled to the free ends of a three-point hitch A scoop-shaped enclosure is pivotally fixed to the bottom of this framework. The scoop-shaped enclosure has a lip along its upper edge that is hooked over the top of the framework.
U.S. Pat. No. 4,986,722 is directed to a mounting structure for a loading attachment. The structure includes two opposing tubular extensions at the bottom front ends of a pair of tractor loader arms and a shallow upwardly facing trough at the top of the ends of the loader arms. An implement, here shown as bucket, has an elongated tubular section that is sized to fit in the trough. The implement is supported by the trough. When the arms are lifted, the bucket pivots inward toward the tractor along its bottom edge and has horizontal slots that engage the two opposing tubular extensions extending from the bottom of the free ends of the loader arms.
U.S. Pat. No. 5,088,882 is directed to a universal coupling for coupling a front end working member, such as a bucket or other implement, to the ends of the loader lift arms of a tractor. The implement includes two downwardly opening hooks extending directly from the surface of the bucket and two lower more widely spaced-apart eyes. The hooks engage a short tubular member fixed to and extending between two vertically extending spaced apart plates. The plates are spread apart at their bases and define two slots therebetween for receiving the eyes of the bucket. There are holes in the plates for receiving laterally extending elongate members such as pins, bolts or the like that extend through the plates and through the eyes to hold them together. In this manner, the bucket or other implement is fixed to the ends of the vehicle's loader arms.
U.S. Pat. No. 5,403,144 is directed to a blade tilt assembly for a front end loader. The assembly includes a generally flat plate that extends laterally and vertically with respect to a skid steer vehicle. The plate has a laterally and horizontally extending top edge and a bottom edge that supports pins that can be extended downwardly. This plate is fixed to the ends of the vehicle's loader lift arms to couple a bucket to the skid steer vehicle. A rectangular metal frame is fixed to the back of the bucket, sized to receive the plate fixed to the loader lift arms. The frame includes a downwardly facing slot that receives the top edge of the plate. It also includes two vertically oriented holes that receive the two pins extending from the bottom of the plate. In this manner the top and the bottom of the plate are fixed to the ends of the loader lift arms.
U.S. Pat. No. 5,685,689 is directed to a quick attach system for a front end loader. It includes a blade for a front end loader that has horizontally extending tubular structures along its upper edge. The blade also has two eyes extending outward from and away from the rear of the blade. The loader arms have a framework that receives the blade. This framework includes an elongate tubular member to which are coupled two vertically extending members on each end. These vertically extending members have laterally extending trough-like structures that cradle the tubular structures to support the tubular structures and the blade to which they are coupled. The bottom of the vertically extending members supports slideable pins that engage the eyes on the blade.
U.S. Pat. No. 5,779,329 is directed to a mechanism allowing quick implement attachment to tractors. It includes a framework of a laterally extending rectangular tubular member that is fixed to two vertically extending members at each end of the tubular member. These vertically extending members have hooks at their upper ends and lower ends that face upward to receive laterally extending tubular structures of an implement. The framework is fixed to the ends of jointed arms that extend outward from the rear of a tractor and hold the implement to the ends of the arm. Latches extending across the open tops of the upper hooks hold the implement in place.
U.S. Pat. No. 6,422,805 is directed to a quick coupler for bucket excavators. It is directed to a latch for latching to a tubular structure, for example, a tubular structure on an implement.
U.S. Pat. No. 6,533,319 is directed to a ballast attachment for attaching a ballast to a rear three-point hitch of a tractor. A rod extends longitudinally between the two lower arms of a three-point hitch. A downwardly-facing notch or groove in a ballast receives the rod and rests upon it. In this manner the three-point hitch supports the ballast.
U.S. Patent Application Publication Number US2003/0005605 A1 is directed to a mounting plate for quick attachment bracket and bucket construction.
None of the foregoing references provide an adequate system for coupling directly to the frame or chassis of a tractor or other work vehicle to support an implement. Most disclose structures that are not attached directly to the frame or chassis of the vehicle to provide a mounting point for implements, but are attached to the implements themselves, such as couplings for attaching buckets to the end of implements such as loader arms already attached to the vehicle—they do not disclose a way of attaching the implement itself to the frame or chassis.
What is needed therefore is a hitching structure fixed to the rear of a tractor's frame or chassis for coupling an implement directly to the frame or chassis of the vehicle.
What is also needed is a structure that can be attached quickly and with a minimum of effort to the rear frame of a tractor and to a variety of implements.
What is also needed is a structure having surfaces that are readily couplable to a variety of implements.
It is an object of this invention to satisfy the foregoing needs by providing a system that, in one or more of its claimed embodiments, solves the problems described above. It should be recognized, however, that not every arrangement claimed below addresses all of the needs and provides all of the benefits identified above.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention, a quick attachment system for a work vehicle having a frame defining an upper pair and a lower pair of holes formed in opposing pairs of vertically and longitudinally extending frame plates, the upper pair of holes having a first common horizontal and laterally extending axis and the lower pair of holes having a second common horizontal and laterally extending axis, the system including a first elongate member extending between a nd coupling the upper pair of holes; a first hook that opens downward to engage the first elongate member adjacent a first of the upper pair of holes; a second hook that opens downward to engage the first elongate member adjacent a second of the upper pair of holes; a first eye having a first hole configured to be disposed adjacent to a first of the lower pair of holes; a second eye having a second hole configured to be disposed adjacent to a second of the lower pair of holes; and a plate that is coupled to and between the first and second eyes and the first and second holes.
The plate may be configured to extend generally perpendicularly to the longitudinal axis of the vehicle. The first hook and the first eye may be disposed on a first elongate member fixed to the plate, and the second hook and the second eye may be disposed on a second elongate member fixed to the plate. The first and second elongate members may extend vertically along the plate. The system may further include a drawbar, and the plate may include an aperture disposed along the lower edge of the plate that is configured to receive the drawbar and support the drawbar in a generally horizontal and longitudinally extending position. The plate may include a plurality of holes configured to receive threaded fasteners to fix an implement directly to the plate. The draw bar may be disposed to extend underneath the implement.
In accordance with a second aspect of the invention, a quick attachment system for coupling a drawbar and an implement directly to a frame of a work vehicle, where the frame includes two laterally opposed frame plates that extend longitudinally and are perpendicular to the ground, each of the frame plates having an upper hole and a lower hole disposed one above the other at the rear edge of the frame plate, and where the upper holes of the frame plates share a first laterally extending horizontal axis and where the lower holes share a second laterally extending horizontal axis, the system including at least a first laterally extending member coupled to the upper holes of the frame plates; at least a second laterally extending member coupled to the lower holes of the frame plates; a first hook that opens downward to engage the at least a first member adjacent a first of the upper pair of holes; a second hook that opens downward to engage the at least a first member adjacent a second of the upper pair of holes; a first eye having a first hole engaging the at least a second member; a second eye having a second hole engaging the at least a second member; and an implement mounting plate coupled to and between the first and second eyes and the first and second holes, the plate having mounting holes for attaching an implement thereto and an aperture for receiving a drawbar.
The mounting plate may extend perpendicular to the longitudinal axis of the vehicle. The first hook and the first eye are disposed on a first elongate member fixed to the plate, and further the second hook and the second eye are disposed on a second elongate member fixed to the mounting plate. The at least a first member may be a single cylindrical pin extending between and coupling the upper holes, and the at least a second member may include a first lower pin coupling the first eye to one of the lower holes of the frame plates and a second lower pin coupling the second eye to another of the lower holes of the frame plates. The system may also include a drawbar, and the mounting plate may include an aperture that is configured to receive the drawbar and support the drawbar in a generally horizontal and longitudinally extending position. The mounting plate may define a plurality of holes extending therethrough and the mounting plate may be configured to receive threaded fasteners to fix an implement directly to the mounting plate. The draw bar may be disposed to extend underneath the implement.
In accordance with a third aspect of the invention, a quick attachment system is provided for a work vehicle having a frame defining an upper and a lower pair of coupling holes formed in opposing pairs of vertically and longitudinally extending frame plates, the upper pair of holes having a first common horizontal and laterally extending axis and the lower pair of holes having a second common horizontal and laterally extending axis, the system including a means for coupling the upper pair of holes; a first means for engaging the first elongate member adjacent a first of the upper pair of holes; a second means for engaging the first elongate member adjacent a second of the upper pair of holes; a third means disposed adjacent to a first of the lower pair of holes for coupling to the first hole of the lower pair of holes; a fourth means disposed adjacent to a second of the lower pair of holes for coupling the second of the lower pair of holes; and a means for coupling the first second, third and forth means together and for attaching to and supporting an implement.
The first means and second means may include two parallel spaced-apart downwardly opening hooks. The third and fourth means include two parallel space-apart eyes. The first of each of the two hooks and two eyes may be disposed together on a first elongate member fixed to the means for coupling, and further, a second of each of the two hooks and two eyes may be disposed together on a second elongate member fixed to the means for coupling. The system may include a drawbar, and the means for coupling may include at least one mounting plate, and the at least one mounting plate may include an aperture disposed along the lower edge of the at least one mounting plate that is configured to receive and support the drawbar. The system may include an implement drawbar, and further the at least one mounting plate may include an aperture disposed along the lower edge of the at least one mounting plate that is configured to receive the drawbar and support the drawbar in a generally horizontal and longitudinally extending position.
BRIEF DESCRIPTION OF THE FIGURES
Preferred exemplary embodiments of the present invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout.
FIG. 1 is a side view of a vehicle train, including a work vehicle having a hitching structure fixed to the rear of its frame, an implement mounted on the hitching structure, and a wheeled vehicle pivotally coupled to the hitching structure by a drawbar.
FIG. 2 is a perspective exploded view of the rear of the tractor of FIG. 1 , showing the two plates that form the rear of the frame, the hitching structure, the pins that couple the hitching structure to the chassis, the ballast that is coupled to the hitching structure, and the drawbar that is coupled to the hitching structure.
FIGS. 3 , 4 , and 5 are bottom, front and left side views of the hitching structure as it would be fixed to the frame of the tractor of FIGS. 1–2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1–5 , a work vehicle, shown as tractor 100 in FIGS. 1 and 2 , has a frame 102 to which a hitching structure 104 is mounted. An implement 106 (here shown as a ballast or counterweight) is fixed to the hitching structure. A drawbar 110 is also fixed to hitching structure 104 and extends rearward underneath implement 106 whereat it is coupled to the tongue 108 of a towed implement 112 (here shown as a four-wheel trailer).
Tractor 100 is a New Holland Model LV-70 tractor. It has a frame 102 that includes two elongated rearwardly extending members. These members extend both vertically and generally fore-and-aft to define two spaced-apart plates 114 , and 116 at the rear of the tractor.
Frame plates 114 and 116 each include two holes for mounting attachments to the vehicle. Plate 114 has an upper hole 118 and a lower hole 120 . Hole 118 is disposed vertically above hole 120 . Each of these two holes extends laterally through plate 114 , and each hole 118 , 120 defines a generally laterally extending and horizontal axis. Plate 116 has an upper hole 122 and a lower hole 124 . Hole 122 is disposed vertically above hole 124 . Each of these two holes 122 , 124 extends laterally through plate 116 , and each hole 122 , 124 defines a generally laterally extending and horizontal axis. Holes 118 and 122 are coaxial. Holes 120 and 124 are also coaxial. Each of holes 118 , 120 , 122 , and 124 extends through semicircular protrusions from the generally vertical rear edge 125 of their respective frame plates.
The hitching structure 104 is coupled directly to frame 102 of vehicle 100 by an upper pin 126 , a left side lower pin 128 , and a right side lower pin 130 . Each of these three pins is fixed in place by snap rings 132 that are installed in grooves at both ends of each pin. These snap rings prevent the pin from being withdrawn once it is in place.
The upper pin is a laterally extending member coaxial with the two upper holes. While a single pin is preferred, separate pins or laterally extending members may be fixed to or engaged with the upper holes to support the hooks of the hitching structure 104 .
The lower pins are laterally extending members coaxial with the lower holes. While two pins are preferred, a single pin or laterally extending member may be employed to couple the eyes of the hitching structure to their respective lower holes.
The hitching structure includes two hooks, a left-hand hook 134 and a right-hand hook 136 , disposed on the left and the right side of the hitching structure 104 , respectively. Hooks 134 and 136 open downwardly to receive and be supported by a cylindrical structure (in this case upper pin 126 ) when the hitching structure is lowered down upon pin 126 . The internal radius of the hooks is nominally +25 mm, slightly larger than the 50 mm outer diameter of pin 126 .
The hooks are coaxial and parallel to each other. The inner radial surfaces of both hooks are defined by a laterally extending horizontal axis 138 .
When mounted on the tractor 100 , hooks 134 , 136 face forward to engage the pin along the length of the pin that extends between frame plates 114 and 116 . Hooks 134 , 136 are 30 mm thick as measured in the lateral direction.
Below each of the two hooks 134 , 136 , are two corresponding eyes 140 , 142 that are parallel to each other and in a spaced-apart relation. Eye 140 is disposed directly below hook 134 and eye 142 disposed directly below hook 136 . Holes 144 , 146 , that define respective eyes 140 , 142 , are coaxial, sharing a common laterally extending longitudinal and horizontal axis 148 . Axis 148 , which passes through and defines holes 144 and 146 , is directly below and parallel to axis 138 that defines the curved inner surface of hooks 134 and 136 .
Eyes 140 and 142 are secured to holes 120 and 124 by pins 128 and 130 , respectively. Pin 128 passes through and couples holes 144 and 120 . Pin 130 passes through and couples holes 146 and 124 .
Hooks 134 and 136 are spaced apart such that they both just fit between plates 114 and 116 with hook 134 adjacent to and abutting frame plate 114 , and hook 136 adjacent to and abutting frame plate 116 . Eyes 140 and 142 are similarly spaced apart such that they both just fit between plates 114 and 116 with eye 140 adjacent to and abutting frame plate 114 and eye 142 adjacent to and abutting frame plate 116 . The clearance between the hooks and eyes, and the plates is on the order of 0.5 to 2.0 millimeters. This close spacing prevents the hooks and eyes from sliding laterally and rubbing against the pins that support them.
In the preferred embodiment, left side hook 134 and eye 140 are formed from a single elongate member, here shown as a vertically extending elongate bar of steel 149 . Similarly, right side hook 136 and eye 142 are preferably formed from a single elongate member, shown here as a vertically extending elongate bar of steel 150 .
In addition to elongate members 149 and 150 , hitching structure 104 includes a vertically and laterally extending plate 152 to which member 149 and 150 are fixed (by welding in this case). Plate 152 has four through-holes 154 , 156 , 158 , 160 , that are arranged in a rectangular pattern. The holes are laterally spaced apart about 320 mm and are vertically spaced apart 280 mm.
Threaded fasteners 162 , 164 , 166 , and 168 are inserted through these through-holes to fasten plate 152 (and hence hitching structure 104 ) to implement 106 . In the embodiment of FIGS. 1 and 2 , implement 106 is a ballast used to anchor the rear wheels more firmly on the ground.
Plate 152 has a lateral width of 580 mm, a thickness of 20 mm and a height of 465 mm. This provides a suitable area for coupling an implement to, whether that implement is a ballast, such as illustrated here, a backhoe attachment, a pavement breaker, saw or other device.
Hitching structure 104 also includes a horizontal rib 170 that extends horizontally across the forward face of plate 152 . This rib is disposed generally perpendicularly to the surface of the plate extending outward and forward from plate 152 . It is fixed (preferably by welding) on each end to vertical hook and eye members 149 and 150 .
Hitching structure 104 further includes a vertical rib 172 that is also fixed (preferably by welding) to the forward surface of plate 152 . Rib 172 is disposed along the lateral centerline of plate 152 and is fixed (preferably by welding) at its upper end to rib 170 .
Hitching structure 104 also includes an upper drawbar coupling 174 that is fixed (preferably welded) to plate 152 just above the bottom edge of plate 152 . Drawbar coupling 174 is preferable formed as a single horizontally extending elongate member that is fixed (preferably by welding) to plate 152 and to vertical members 149 and 150 at each of the ends of coupling 174 .
Coupling 174 has a vertically extending hole 176 that passes through coupling 174 forward of plate 152 . Hole 176 is sized to receive a standard drawbar coupling pin 190 passing therethrough.
Hitching structure 104 includes a second drawbar coupling 178 that is also fixed (preferably welded) to a downwardly extending protrusion 180 of plate 152 just above the bottom edge of plate 152 . Drawbar coupling 178 is preferable formed as a single horizontally extending member. Coupling 178 like coupling 174 has a vertically extending hole 182 that is coaxial with and directly underneath hole 176 such that drawbar coupling pin 190 passing through hole 176 will continue on into hole 182 .
The bottom of plate 152 includes an aperture 184 , here shown as a slot, which is formed therein. This aperture is configured to receive drawbar 110 to which vehicle 112 or other implement may be coupled.
To couple an implement to the tractor, drawbar 110 is first coupled to hitching structure 104 . Drawbar 110 is an elongate member having an aperture 188 that is sized to receive a pin passing through holes 176 and 182 of the drawbar couplings. The forward end of drawbar 110 is passed through aperture 184 of plate 152 until aperture 188 is axially aligned with holes 176 and 182 . Once in this position, a pin 190 is passed through and retained in holes 176 , 182 and aperture 188 . Pin 190 prevents drawbar 110 from being withdrawn from hitching structure 104 . The opposite end of drawbar 110 includes a second aperture 191 to which a towed implement 112 is coupled.
Drawbar 110 extends completely underneath the implement fixed to plate 152 (e.g. the ballast) and out from under the rear of the implement. In this manner, the rear end 192 of drawbar 110 can be easily coupled to various towed implements and also can be easily removed prior to the removal of hitching structure 104 from frame 102 of tractor 100 .
The combined vehicle in FIG. 1 may be assembled as follows. First, the operator inserts upper pin 126 through holes 118 and 122 in plates 114 and 116 . The operator also fixes retaining rings 132 to both of the free ends of pin 126 to prevent pin 126 from slipping out of holes 118 and 122 .
The operator also attaches hitching structure 104 to implement 106 by passing threaded fasteners 162 , 164 , 166 , and 168 through holes 154 , 156 , 158 , 160 , respectively, and threading them into corresponding threaded holes 196 , 198 , 200 , 202 in implement 106 .
The operator then lifts combined implement 106 and hitching structure 104 and maneuvers the combined structure into position until the open ends of hooks 134 and 136 are disposed above pin 126 . The operator then lowers the combined implement and hitching structure until the root of hooks 134 , 136 , rests on pin 126 supporting the weight of implement 106 .
Once a portion of the weight of the combined structure 104 and 106 is resting on pin 126 , lower holes 120 , 124 of plates 114 , 116 can be readily aligned with holes 144 , 146 of eyes 140 , 142 , respectively. This is true since the vertical spacing between holes 118 , 122 and holes 120 , 124 is the same as the spacing between the cylindrical root of hooks 134 , 136 and holes 144 , 146 , respectively. Resting hooks 134 , 136 on pin 126 automatically aligns the lower holes with a modicum of implement pivoting.
With the implement pivoted into the proper position to align the lower holes, the operator inserts pin 128 through holes 120 and 144 , and inserts pin 130 through holes 124 and 146 . The operator then attaches retaining rings 132 to the free ends of pins 128 and 130 to hold them in the holes.
At this point, the implement is fixed to the rear frame of the tractor with one intermediate structure: hitching structure 104 . It cannot move relative to the tractor frame. It cannot be raised or powered by hydraulic cylinders or other adjusting devices.
With the implement in place, the operator can then release the implement (which has most probably been lifted in place by other mechanical means, such as a chain fall, crane, forklift, telehandler, or improvised lifting device such as the bucket of another tractor), and let the tractor support the entire weight of the implement.
With the hitching device and implement securely fixed to the back of the tractor, there is room for the operator to reach under implement 106 and insert drawbar 110 through aperture 184 of plate 152 . The operator slides the drawbar 110 forward until holes 176 and 182 are aligned with aperture 188 of drawbar 110 .
The operator then inserts pin 190 through holes 176 , 182 and aperture 188 and secures the pin in place.
With the drawbar in position, the operator then attaches tongue 108 of towed implement 112 to the free rear end 192 of drawbar 110 . The entire vehicle shown in FIG. 1 is now assembled and ready for transport.
While the embodiments illustrated in the FIGURES and described above are presently preferred, it should be understood that these embodiments are offered by way of example only. The invention is not intended to be limited to any particular embodiment, but is intended to extend to various modifications that nevertheless fall within the scope of the appended claims.
For example, while two upper hooks and two lower eyes are illustrated, two upper eyes and two lower hooks may be employed instead, or four upper and lower eyes, or four upper and lower hooks employed.
While the hooks and eyes are illustrated as parts of two vertically extending members, each hook and eye may be separately attached to the mounting plate of the hitching structure.
While there are four mounting holes illustrated in the figures, a mounting plate with no holes may be provided, for example, to attach the mounting plate to an implement by welding, or by using threaded fasteners that extend through the implement and thence into the mounting plate. Alternatively, several holes may be provided in the mounting plate, but they may be disposed in a different pattern unlike the rectangular pattern illustrated here.
The mounting plate, while shown here as flat, may be somewhat curved, for example to accommodate a curved cast portion of an implement. It may also be less than perfectly flat by defining mounting pads, lands, ribs or other structures rising above the surface of the mounting plate for engaging with similar pads, lands or ribs on an implement.
A variety of generally cylindrical structures may be employed in place of the pins shown herein, such as bolts, screws, or other threaded fasteners; spring pins; generally cylindrical nipples, cones or other protrusions that may be inserted into the upper or lower holes and mate with them.
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A system for quickly coupling a mounted implement and a towed implement to a tractor frame or chassis includes a hitching bracket with two hooks and two eyes that are fixed to the frame of the tractor and a plate that is fixed to the hooks and eyes to provide a mounting surface for the implement. The plate also includes a slot for inserting a drawbar that can be attached to a towed vehicle. The drawbar is positioned underneath the implement.
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BACKGROUND OF THE INVENTION
The invention relates to a device for feeding a pulp suspension to a dewatering installation, particularly for a tissue machine.
This type of device, also known as a headbox, has a major influence on paper formation and thus, on paper quality. In the headboxes used to date, the pressure provided practically the only means of controlling the flow rate of the pulp suspension. In two-layer and multi-layer headboxes, however, which provide a means of influencing the quality of the paper surface, it is not possible to run the different flow rates needed to obtain, for example, different qualities of top and bottom layer.
SUMMARY OF THE INVENTION
The aim of the invention is thus to improve the field of application for and the means of controlling headboxes.
The invention is thus characterized by one or several one-piece, wedge-shaped, steel lamella tip(s) being provided to separate the individual sectors in a two-layer or multi-layer headbox. In this way it is possible to achieve stable layer separation and thus, a constant setting of the slice gap heights, even at different feed pressures, with the effect that a differential speed can be set between the individual suspension streams.
An advantageous further development of the invention is characterized by the lamella tip(s) being attached under pre-stress by a tie rod to the partition of the feed device. This allows the setting of the slice gap heights to be particularly stable and as a result, precise.
A favorable configuration of the invention is characterized by the spacing of the bottom lip and/or the top lip to the lamella tip being adjustable. In this way, the lamella tip can be securely fixed and made very stable.
An advantageous configuration of the invention is characterized by an eccentric shaft being provided to set the slice gap between a minimum and a maximum height. By setting the height of the slice gap, the flow rate of the suspension stream can easily be adjusted to the needs of the final product. Since an eccentric shaft is used, this guarantees high-precision adjustment of the slice gap.
A favorable further development of the invention is characterized by the top lip being adjustable using an eccentric shaft, where the bottom lip can also be made adjustable with an eccentric shaft either as an alternative or in addition. The facility for setting the top and/or bottom lip, depending on whether the headbox is of two-layer or multi-layer design, permits optimum conditions for regulating the flow rate for the individual layers.
A favorable configuration of the invention is characterized by a partition and lamella tip unit being adjustable by means of an eccentric shaft.
An advantageous configuration of the invention is characterized by the eccentric shaft being supported at several points over the machine width, where these supports can be positioned at regular intervals.
A favorable further development of the invention is characterized by the eccentric shaft being connected to a gear motor. In this way the slice gap and thus, the flow rate of the pulp suspension can also be set or adjusted accordingly while the paper machine is in operation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in examples and referring to the drawings, where
FIG. 1 is a cross-sectional view of a two-layer headbox in accordance with the invention;
FIG. 2 is a cross-sectional view of a three-layer headbox in accordance with the invention;
FIG. 3 is cross-sectional view along the line III—III of FIG. 2;
FIG. 4 is an enlarged cross-sectional view of the upper and lower lips, the lamella tip, tie rods and outlet chambers of the headbox of FIG. 1; and
FIG. 5 is an enlarged cross-sectional view of the upper and lower lips, the lamella tips, tie rods and outlet chambers of the headbox of FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a device for feeding pulp suspensions to a dewatering installation, particularly for a tissue machine, in the form of a two-layer headbox. Here the suspension is fed in through two channels 1 simultaneously at right angles to the machine direction, then the flow direction of the suspension is turned through 90 degrees into the machine direction. The suspension is then fed through two turbulence chambers 2 into the outlet chambers 3 , 4 , which are designed as nozzle areas, with the suspension leaving the device at the end of these chambers and entering the dewatering installation. The two nozzle areas 3 , 4 are divided by a partition 8 which is attached under pre-stress to the supporting structure 10 by means of hollow screws 9 . At the outlet end of the partition 8 there is a one-piece, wedge-shaped lamella tip 12 made of stainless steel, which is attached under pre-stress to the partition 8 by tie rods 13 . When assembled, the partition 8 and the lamella tip 12 form a fixed dividing element between the two nozzle areas 3 and 4 . Since this element is attached under pre-stress to the supporting structure 10 , it is possible to apply different operating pressures (up to 0.5 bar) and thus, different suspension flow speeds for each layer.
In order to do this, the slice gaps a and b of the two nozzles areas 3 , 4 must be set at different heights. For this purpose the top lip 18 and the bottom lip 18 ′ are pivoted round the articulated joints 14 and 14 ′. This pivoting movement is implemented by an eccentric shaft 16 , 16 ′, which is supported in bearings 17 , 17 ′ on the rigid cover plates 20 , 20 ′ of the device at regular intervals over the machine width. Due to the eccentricity e of the shafts, the slice gaps a and b can be set between a minimum and a maximum height.
The structure is designed such that the top lip 18 and the bottom lip 18 ′ never touch the lamella tip 12 and thus no damage can occur, even when the eccentric shaft 16 , 16 ′, is rotated continuously by a drive 22 .
Due to this adjustment of the top and bottom lip using eccentric shafts 16 , 16 ′, the contour angle α at the two-layer headbox is smaller than in conventional adjustments using gear motors. This permits a substantial reduction in the length of the free flow path f of the pulp jet from the headbox outlet until coming into contact with the wires or felts running over the rolls. This then leads to improved stability in the free-flow jet and thus, to an improvement in paper quality.
Due to the rigid lamella tip 12 and the resulting means of providing different suspension flow rates in the two chambers (nozzle areas) 3 , 4 , there is an improvement in paper quality in the operating mode for “same pulp types” in both chambers and very good separation (covering) of the layers in the operating mode for “different pulp types” in both chambers compared with single-layer and multi-layer headboxes with flexible partition elements at the nozzle area outlets, which do not permit any difference between the two pulp layers.
FIG. 4 shows a detail of the slice gap in FIG. 1 . The difference in size between the slice gaps a (nozzle area 3 ) and b (nozzle area 4 ) is clearly shown here.
FIG. 2 now shows a three-layer headbox, where the suspension is fed into the device through three channels 1 simultaneously at right angles to the machine direction, then the direction of flow is turned through 90 degrees into the machine direction. The suspension then flows through three turbulence chambers 2 into the outlet chambers, known as nozzle areas 3 , 4 , 5 , at the end of which it leaves the device and enters the dewatering machine. Here, the suspension is injected into the gap between two wires which run over two rolls.
The two nozzle areas 4 , 5 are separated by a partition 8 , the same as the design in FIG. 1 . At the end of this partition 8 there is a one-piece, wedge-shaped lamella tip 12 made of stainless steel. When assembled, the partition 8 and the lamella tip 12 form a fixed, non-adjustable dividing element between the two nozzle areas 4 , 5 . Since this element is attached under pre-stress to the supporting structure 10 , it is possible to obtain differences of up to 0.5 bar and thus, different flow rates in the pulp suspension for the two layers.
The two nozzle areas 3 , 4 are separated by a partition 6 which pivots round an axis 7 . At the outlet end of the partition 6 there is also a one-piece lamella tip 12 ′ made of stainless steel, which is attached under pre-stress to the partition 6 by tie rods 11 . The partition 6 and the lamella tip 12 ′ thus form a rigid dividing element which can, however, be pivoted in one piece round the axis 7 . This pivoting movement is effected by an eccentric shaft 15 , which is supported in bearings 19 on the rigid rear wall 23 of the device at regular intervals over the machine width.
Due to this eccentricity e, the slice gap c of the nozzle area 4 can be set between a minimum and a maximum height and secured at the height selected. The slice gaps a and b of the two nozzle chambers 3 and 5 can also be set and secured between a minimum and a maximum height. In order to do this the top lip 18 and the bottom lip 18 ′ are pivoted round the articulated joints 14 , 14 ′. This pivoting movement is effected by an eccentric shaft 16 , 16 ′, supported in bearings 17 , 17 ′ on the rigid cover plates 20 , 20 ′ of the device at regular intervals over the machine width. The eccentricity e of the shafts 16 , 16 ′ allows the slice gaps a and b to be set between a minimum and a maximum height.
The structure is designed such that the top lip 18 and the bottom lip 18 ′ never touch the lamella tip 12 , 12 ′, and thus no damage can occur, even when the eccentric shaft 16 , 16 ′ is rotated continuously by a drive 22 . The same applies for all positions of the adjustable partition 6 with lamella tip 12 ′.
Due to this adjustment of the top and bottom lip using eccentric shafts 16 , 16 ′, the contour angle β at the three-layer headbox is smaller than in conventional adjustments using gear motors. This also permits a substantial reduction in the length of the free flow path f of the pulp jet from the headbox outlet until coming into contact with the wires or felts running over the rolls. This then leads to improved stability in the free-flow jet and thus, to an improvement in paper quality.
As a result, it is also possible to operate the three-layer headbox with different flow speeds for the inner and for the two outer layers.
In addition to the advantages already mentioned for the two-layer headbox, such as paper quality, covering and separation of layers, a further advantage with a three-layer headbox is that poorer quality pulp can be used for the middle layer without this having a detrimental effect on the quality of the paper.
FIG. 5 shows a detail of the slice gap illustrated in FIG. 2 . Here we can see different settings of slice gap heights a (nozzle area 3 ), b (nozzle area 5 ), and c (nozzle area 4 ).
FIG. 3 shows a section through the line marked III—III in FIG. 1 and also in FIG. 2 . The eccentric shaft 16 is shown here, supported in bearings 17 at several points over the machine width. A gear motor 22 is also shown for setting the height of the slice gap.
The invention is not limited to the examples described. Other forms of lip adjustment device can also be provided.
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The invention refers to a device for feeding a pulp suspension to a dewatering installation, particularly for a tissue machine. It is mainly characterized by one or several one-piece, wedge-shaped, steel lamella tip(s) being provided to separate the individual sectors in a two-layer or multi-layer headbox.
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TECHNICAL FIELD
The present invention generally concerns firearm equipment. More particularly, the present invention relates to a firearm handguard assembly.
BACKGROUND OF THE INVENTION
Traditionally, a handguard is mounted to a firearm using an assembly that uses a basic clamp on the handguard (which may or may not be integrated with the handguard itself) with a slice-bottom design, wherein the bottom portion of the clamp is held together with screws, a two-sided slice design, or a multi-part clamp design. When the screws are tightened, the clamp bears down on the handguard, holding the handguard to the barrel nut. The barrel nut holds the barrel of the firearm in place and is attached to the upper receiver. However, this design is problematic. The tension created by the clamp holds the handguard in place on the barrel nut, but places stress on the upper area of the handguard, which is weaker due to design constraints. This area expands as the clamping mechanism is tightened and more so when the firearm is in use due to the heat generated between the barrel of the firearm, which causes the stress imparted by the clamp to relax as the parts expand due to heat. Traditional designs have placed their hardware in a disadvantaged location due to the lack of clearance available between the various components on top of the barrel nut. There is, therefore, a need for an improved firearm handguard assembly system that obviates the shortcomings of the traditional clamping design.
Similarly, even when a handguard is properly mounted to a firearm, the movement of the handguard may loosen the barrel nut and could result in damage to the firearm. Several solutions have been offered to index the handguard to the upper receiver of the firearm. The most common solution is an anti-slip plate that is affixed to the barrel nut using several screws. This type of assembly can be complicated and time-consuming for the user. Yet another design is a handguard with an indexing tab (or “finger”) that extends from the handguard and indexes to the upper receiver of the firearm. Therefore, there is a need for an indexing system that is simple and user-friendly.
The present invention is aimed at one or more of the problems identified above.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1A illustrates an exploded view of an exemplary handguard assembly according to a first embodiment;
FIG. 1B illustrates a side perspective view of an index block of an exemplary handguard assembly according to a first embodiment;
FIG. 1C illustrates a front view of an index block and a barrel nut of an exemplary handguard assembly according to a first embodiment;
FIG. 1D illustrates a back view of an index block and a barrel nut of an exemplary handguard assembly according to a first embodiment;
FIG. 1E illustrates a top view of an index block of an exemplary handguard assembly according to a first embodiment;
FIG. 1F illustrates a bottom view of an index block of an exemplary handguard assembly according to a first embodiment;
FIG. 1G illustrates a perspective view of a fully assembled exemplary handguard assembly system according to a first embodiment;
FIG. 1H illustrates a cross-sectional view of a of a fully assembled exemplary handguard assembly system according to a first embodiment;
FIG. 1I illustrates a fully assembled firearm handguard assembly system on an exemplary firearm according to a first embodiment;
FIG. 2A illustrates an exploded view of an exemplary handguard assembly according to a second embodiment;
FIG. 2B illustrates a side perspective view of an index block of an exemplary handguard assembly according to a second embodiment;
FIG. 2C illustrates a front view of an index block and a barrel nut of an exemplary handguard assembly according to a second embodiment;
FIG. 2D illustrates a back view of an index block and a barrel nut of an exemplary handguard assembly according to a second embodiment;
FIG. 2E illustrates a top view of an index block of an exemplary handguard assembly according to a second embodiment;
FIG. 2F illustrates a bottom view of an index block of an exemplary handguard assembly according to a second embodiment;
FIG. 2G illustrates a perspective view of a fully assembled exemplary handguard assembly system according to a second embodiment;
FIG. 2H illustrates a cross-sectional view of a of a fully assembled exemplary handguard assembly system according to a second embodiment; and
FIG. 2I illustrates a fully assembled firearm handguard assembly system on an exemplary firearm according to a second embodiment.
Corresponding reference characters indicate corresponding parts throughout the drawings.
SUMMARY OF THE INVENTION
In one aspect of the present invention, a firearm handguard assembly system is disclosed. The system comprises a handguard, a barrel nut, and an index block. The handguard has at least four apertures. The barrel nut has first threaded end and a second smooth end. The threaded end is coupled to the handguard. The index block includes at least four apertures. The index block is coupled to the handguard by at least four screws. Each screw has a head and a tip. The tip of each screw is threaded through one of the apertures on the index block and one of the apertures on the handguard.
In another aspect of the present invention, a firearm is disclosed. The firearm includes an upper receiver, a handguard including at least four apertures; and a handguard assembly system. The handguard assembly system is used for mounting the handguard to the upper receiver. The handguard assembly system includes a barrel nut having a first threaded end and a second smooth end, the threaded end coupled to the handguard. The handguard assembly system further includes an index block including at least four apertures. The index block is coupled to the handguard by at least four screws, each screw having a head and a tip. The tip of each screw is threaded through one of the apertures on the index block and one of the apertures on the handguard.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention provide a handguard assembly and system and method of mounting the assembly to a firearm. Persons of ordinary skill in the art will realize that the following description of the presently invention is illustrative only and not in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled persons.
Other improved designs have included the use of clamp blocks, cross bolts, and an indexing plate, as described in U.S. Pat. No. 8,904,691, issued to Eric S. Kincel, which is incorporated herein by reference. The design of the present invention uses screws and an index clamp rather than cross bolts and a plurality of clamp blocks.
Referring now to FIG. 1A , illustrating an exploded view of a firearm handguard assembly system according to a first embodiment, a handguard 100 is coupled to a threaded end of barrel nut 102 to mount the upper receiver of a firearm ( FIG. 1I ) to handguard 100 .
It is contemplated that any handguard may be used in connection with the present invention. In a preferred embodiment, the handguard is made from magnesium rather than aluminum, the typical material for handguards in the industry. Magnesium is lighter than aluminum by a ratio of 1:3, and is therefore an ideal structural material for handguards because it reduces strain on the firearm user during use. However, handguards made from any suitable structural material may be used in connection with the present invention, including without limitation steel (carbon and stainless), aluminum, and titanium.
It is also contemplated that the handguard may contain KeyMod holes, a picatinny rail (also known as a MIL-STD-1913 accessory rail), Magpul® M-LOK® System, GIBBZ Arms™ Modular Attachment (GAMA) System, and/or any other interface system currently available or later developed.
According to the first embodiment, the threaded end of barrel nut 102 is placed inside a first end of handguard 100 . Without an index block or plate, the movement of the handguard may loosen the barrel nut and could result in damage to the firearm. Use of index block 104 eliminates rotation of handguard 100 during use.
A first end of handguard 100 contains a first aperture 106 and a second aperture 108 on a first side, and a third aperture 110 and a fourth aperture 112 on a second side. Index block 104 contains a first aperture 114 and a second aperture 116 on a first side, and a third aperture 118 and a fourth aperture 120 on a second side. Index block 104 is placed inside the first end of handguard 100 such that first aperture 114 of index block 104 is aligned with first aperture 106 of handguard 100 and second aperture 116 of index block 104 is aligned with second aperture 108 of handguard 100 . On the second side of index block 104 , third aperture 118 of index block 104 is aligned with third aperture 110 of handguard 100 and fourth aperture 120 of index block 104 is aligned with fourth aperture 112 of handguard 100 .
A first screw 122 is threaded through first aperture 106 of handguard 100 and first aperture 114 of index block 104 . A second screw 124 is threaded through second aperture 108 of handguard 100 and second aperture 116 of index block 104 . A third screw 126 is threaded through third aperture 110 of handguard 100 and third aperture 118 of index block 104 . A fourth screw 128 is threaded through fourth aperture 112 of handguard 100 and fourth aperture 120 of index block 104 .
Index block 104 further includes feet, one of which is labeled 130 , which interface with barrel nut 102 .
During threading as described above, screws 122 , 124 , 126 , and 128 preclude longitudinal movement of handguard 100 , while clamping down on the body of handguard 100 to cause residual force between barrel nut 102 and handguard 100 . On an AR-15 platform, the mounting force is spread around the firearm's gas tube (see FIG. 1H ). The residual mounting force prevents the handguard from flexing or growing, which ultimately prevents rotation and slippage during use.
Referring now to FIG. 1B , a side perspective view of index block 104 and barrel nut 102 of an exemplary handguard assembly according to the first embodiment is shown. Screws 122 , 124 , 126 , and 128 are threaded through index block 104 . Feet 130 of index block 104 interface with barrel nut 102 in a groove 132 between a first lip 134 of the threaded end barrel nut 102 and a second lip 136 of the smooth end of barrel nut 102 .
Referring now to FIGS. 1C and 1D , a front view and a back view of index block 104 and barrel nut 102 of an exemplary handguard assembly according to the first embodiment are shown, respectively.
Referring now to FIGS. 1E and 1F , a top view and a bottom view of index block 104 of an exemplary handguard assembly according to the first embodiment are shown, respectively.
Referring now to FIG. 1G , illustrating a fully assembled firearm handguard assembly system according to the first embodiment, the barrel nut 102 is secured inside handguard 100 with screws 122 , 124 , 126 , and 128 , and with indexing block 104 in place, allowing handguard 100 to be fully indexed to the upper receiver of the firearm ( FIG. 1I ). The design of the firearm handguard assembly strengthens the grip of the handguard on the barrel nut, by eliminating non-continuous features within the clamping area of the handguard body, keeping the handguard tensioned in place even under high stress and heat when the firearm is in use.
Referring now to FIG. 1H , illustrating a cross-sectional view of a of a fully assembled exemplary handguard assembly system according to the first embodiment, the handguard 100 includes gas tube 138 and barrel 140 .
Referring now to FIG. 1I , illustrating a fully assembled firearm handguard on an exemplary firearm according to the first embodiment, the handguard 100 is secured to exemplary firearm 142 at its upper receiver with index block 104 and screws 122 , 124 , 126 , and 128 in place.
Referring now to FIG. 2A , illustrating an exploded view of a firearm handguard assembly system according to a second embodiment, a handguard 200 is coupled to a threaded end of barrel nut 202 to mount the upper receiver of a firearm ( FIG. 2I ) to handguard 200 .
The threaded end of barrel nut 202 is placed inside a first end of handguard 200 . Without an index block or plate, the movement of the handguard may loosen the barrel nut and could result in damage to the firearm. Use of index block 204 eliminates rotation of handguard 100 during use.
A first end of handguard 200 contains a first aperture 206 and a second aperture 208 on a first side, and a third aperture 210 and a fourth aperture 212 on a second side. Index block 204 contains a first aperture 214 and a second aperture 216 on a first side, and a third aperture 218 and a fourth aperture 220 on a second side. Index block 204 is placed inside the first end of handguard 200 such that first aperture 214 of index block 204 is aligned with first aperture 206 of handguard 200 and second aperture 216 of index block 204 is aligned with second aperture 108 of handguard 200 . On the second side of index block 204 , third aperture 218 of index block 204 is aligned with third aperture 210 of handguard 200 and fourth aperture 220 of index block 204 is aligned with fourth aperture 212 of handguard 200 .
A first screw 222 is threaded through first aperture 206 of handguard 200 and first aperture 214 of index block 204 . A second screw 224 is threaded through second aperture 208 of handguard 200 and second aperture 216 of index block 204 . A third screw 226 is threaded through third aperture 210 of handguard 200 and third aperture 218 of index block 204 . A fourth screw 228 is threaded through fourth aperture 212 of handguard 200 and fourth aperture 220 of index block 204 .
During threading as described above, screws 222 , 224 , 226 , and 228 preclude longitudinal movement of handguard 200 , while clamping down on the body of handguard 200 to cause residual force between barrel nut 202 and handguard 200 . On an AR-10 platform, the mounting force is spread under the gas tube (see FIG. 2H ). The residual mounting force prevents the handguard from flexing or growing, which ultimately prevents rotation and slippage during use.
Referring now to FIG. 2B , a side perspective view of index block 204 and barrel nut 202 of an exemplary handguard assembly according to the second embodiment is shown. Screws 222 , 224 , 226 , and 228 are threaded through index block 204 . Index block 204 interfaces with barrel nut 202 in a groove 232 between a first lip 234 of the threaded end barrel nut 202 and a second lip 236 of the smooth end of barrel nut 202 .
Referring now to FIGS. 2C and 2D , a front view and a back view of index block 204 and barrel nut 202 of an exemplary handguard assembly according to the second embodiment are shown, respectively.
Referring now to FIGS. 2E and 2F , a top view and a bottom view of index block 204 of an exemplary handguard assembly according to the second embodiment are shown, respectively.
Referring now to FIG. 2G , illustrating a fully assembled firearm handguard assembly system according to the second embodiment, the barrel nut 202 is secured inside handguard 200 with screws 222 , 224 , 226 , and 228 , and with indexing block 204 in place, allowing handguard 200 to be fully indexed to the upper receiver of the firearm (see FIG. 2I ). The design of the firearm handguard assembly strengthens the grip of the handguard on the barrel nut, by eliminating non-continuous features within the clamping area of the handguard body, keeping the handguard tensioned in place even under high stress and heat when the firearm is in use.
Referring now to FIG. 2H , illustrating a cross-sectional view of a of a fully assembled exemplary handguard assembly system according to the second embodiment, the handguard 200 includes gas tube 238 and barrel 240 .
Referring now to FIG. 2I , illustrating a fully assembled firearm handguard on an exemplary firearm according to the second embodiment, the handguard 200 is secured to exemplary firearm 242 at its upper receiver with index block 204 and screws 222 , 224 , 226 , and 228 in place.
An exemplary firearm may be an AR-10, AR-15, or a variant thereof. The present invention may also be used with any firearm that uses a threaded portion of the forward area of the upper receiver and/or action over which may pass any portion of the operating assembly. By way of example, and not limitation, these firearms may include bolt action rifles for which the user may desire a handguard or fore-end with a top rail and superior clamping force to the receiver. Exemplary embodiments are illustrated herein. The first embodiment, illustrated by FIGS. 1A-1I , shows the present invention on an AR-15 platform. The second embodiment, illustrated by FIGS. 2A-2B , shows the present invention on the AR-10 platform.
Although the exemplary embodiments described herein contain a block and screw assembly that requires one block and four screws, it is contemplated that more or less than four screws may be used. It is also contemplated that the block may be integrated into the handguard body.
The barrel nuts shown in FIGS. 1A-1I and FIGS. 2A-2I use a radial groove long and deep enough to pass a multitude of screws. Alternative embodiments of the barrel nut include, but are not limited to, a barrel nut design containing a plurality of apertures to allow the screws to pass through the apertures and engage the index block; a barrel nut design with a plurality of flat cuts that create clearance for the screws to pass; a barrel nut design with no forward flange but with a protrusion to support the screws; a barrel nut design without any forward flange, no clearance cuts, and which may have screws passing only in front of, or in front of and behind, the barrel nut in order to engage the apertures on either side of the handguard. The barrel nut and related metal mounting hardware made from any suitable structural material may be used in connection with the present invention, including without limitation steel (carbon and stainless) and titanium.
The above description is illustrative and not restrictive. Many variations of the invention will become apparent to those of skill in the art upon review of this disclosure. While the present invention has been described in connection with a variety of embodiments, these descriptions are not intended to limit the scope of the invention to the particular forms set forth herein. To the contrary, the present descriptions are intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claim and otherwise appreciated by one of ordinary skill in the art.
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A firearm handguard assembly system is disclosed. The system comprises a handguard including at least four apertures, a barrel nut having a first threaded end and a second smooth end, the threaded end coupled to the handguard, and an index block including at least four apertures, the index block coupled to the handguard by at least four screws, each screw having a head and a tip, the tip threaded through: one of the at least four apertures on the index block, and one of the at least four apertures on the handguard.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a Divisional of U.S. patent application Ser. No. 10/799,780, filed Mar. 15, 2004, and is based upon and claims the benefit of priority from the prior Japanese Patent Application No. P2003-352628 filed on Oct. 10, 2003. The entire contents of these applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device and a manufacturing method of the same, and particularly, to a technology employing a fine gate forming process using a sidewall pattern transfer method.
2. Description of the Related Art
In recent years, the performance of a large scale integrated circuit (LSI) formed on a silicon substrate has been significantly increased due to a finer device used for the LSI. In other words, the performance has been improved by reducing, based on a so-called scaling law, a gate length of a metal oxide semiconductor field effect transistor (MOSFET) used for a logic circuit or for a memory device such as a static random access memory (SRAM). Alternatively, the performance may have been improved by thinning a gate insulator.
Among the above, with regard to the reduction of the gate length, it has become more and more difficult to form a fine gate electrode pattern along with changes in generations. In some cases, the gate electrode has become so fine that a resolution limit of optical lithography has already been exceeded. Accordingly, it has become extremely difficult to form a thinner pattern by a conventional combination of resist coating and ultraviolet light exposure and to control a spatial fluctuation of a pattern formed by the above combination.
Therefore, in stead of directly forming a thin gate pattern by using resist, a method has been recently proposed in which: a dummy pattern is first formed; an insulator film, polysilicon, amorphous silicon or the like is deposited onto the dummy pattern; entirely perform reactive ion etching (RIE), which is also called as a sidewall leaving process, to form sidewall portions formed of the deposited film around the sidewalls of the dummy pattern; the dummy pattern is removed thereafter; and a gate electrode or a silicon substrate is processed using the thin sidewall patterns as masks.
For example, a method of processing a silicon substrate by the above method is disclosed in “p. 421, IEDM 2001 Tech. Dig., by Y, -K. Choi, et al.” This method will be hereinafter referred to as a sidewall pattern transfer method. According to this method, the thin pattern formed by the sidewall leaving process is formed basically depending only on the film thickness of the deposited film and an etching condition. In addition, a thin line can be formed even if the fine gate pattern is not formed using resist. In practice, this portion requires a large pattern formation using resist because a contact region for connecting a metal wiring portion with the gate electrode is necessary. However, a thin line pattern of the gate electrode portion to be a channel portion can be formed without using lithography.
Meanwhile, a fin field effect transistor (FinFET), which is one of three dimensional MOSFETs and utilizes as channels side portions of a device region thinly cut out into oblong strips, is described in “p. 1032, IEDM 1998, by D. Hisamoto et al.”
FIG. 29 shows an example of a typical layout of a complementary metal oxide semiconductor (CMOS) inverter (inverter chain) made up of conventional MOSFETs. In this CMOS inverter, a gate electrode region 201 is connected to a drain region 203 of a p-channel MOSFET (pFET), a drain region 202 of an n-channel MOSFET (nFET), and a pad region 209 of a gate electrode. A plurality of source regions 205 of the pFETs and a plurality of source regions 204 of the nFETs are arranged in parallel. Similarly, a plurality of drain regions 202 of the nFETs and a plurality of drain regions 203 of the pFETs are arranged in parallel. A metal wiring 206 supplying a power supply voltage (Vcc) is connected to the source region 205 of the pFET through a pad region 208 . Moreover, a metal wiring 207 supplying a ground voltage (Vss) is connected to the source region 204 of the nFET through the pad region 208 . In this way, only one gate electrode 201 is disposed in one device region. Here, the pad region 209 of the gate electrode is shared by the nFET and the pFET. It is possible to divide the gate electrode into two separate gate electrodes one of which is for the nFET and one for the pFET, and also possible to connect the separate gate electrodes with the metal wiring 206 and 207 , respectively. Further, if a gate length between the adjacent MOSFETs is Lg, a device isolation width 210 is Li, a source region length (channel length direction) is Ls and a drain region length (channel length direction) is Ld, an area occupied by one CMOS inverter is proportional to Li+Ls+Ld+Lg, which determines a pitch between the inverters.
By contrast, FIG. 1 of Japanese Patent Laid-Open Hei 7-202146 (Technical Literature 1) discloses a technology in which a gate electrode encloses a region surrounding a source or drain region in order to suppress a gate resistance increase attributable to a finer gate length in a highly integrated CMOS logic LSI. Here, the gate electrode has an electrically closed loop shape.
However, the gate pattern formed by the sidewall pattern transfer method forms the sidewall portions over the entire dummy pattern. Therefore, the gate electrode here is connected to form a loop shape along the shape of the dummy pattern unlike the conventional straight gate electrode.
Therefore, the gate electrode cannot be formed using the layout of the MOSFET, where the conventional gate electrode structure is employed, as it is. If this layout should be used, a process of processing the gate electrode is further required. Paradoxically, it is clear that, if the shape of the gate electrode formed by the sidewall pattern transfer method is employed as it is, a basic logic circuit such as an inverter cannot be constituted in the layout of the conventional transistor.
SUMMARY OF THE INVENTION
An aspect of the present invention provides a semiconductor device that includes a first transistor including a source region, a drain region provided in a same device region as the source region, and a loop-shaped gate electrode region, and a second transistor sharing, with the first transistor, the loop-shaped gate electrode region and the source region or the drain region.
Another aspect of the present invention provides a semiconductor device that includes a device region where each of a plurality of source regions and each of a plurality of drain regions of transistors are alternately included, and a plurality of loop-shaped gate electrode regions of the transistors which are formed on the device region and part of which are disposed onto two positions between the source regions and the drain regions.
A further aspect of the present invention provides a semiconductor device that includes a first device region including a plurality of source regions and a plurality of drain regions of first conductivity type transistors, a plurality of loop-shaped gate electrode regions of the fist conductivity type transistors, the gate electrode regions being formed on the first device region, a second device region including a plurality of source regions and a plurality of drain regions of second conductivity type transistors, a plurality of loop-shaped gate electrode regions of the second conductivity type transistors, each of the gate electrode regions being formed on the second device region and electrically coupled to each of the gate electrode regions of the first conductivity type transistors, a first wiring configured to supply a first voltage to at least one of the source regions of the first device region, a second wiring configured to supply a second voltage to at least one of the source regions of the second device region, and a third wiring electrically coupled to the drain regions of the first and second device regions and to the gate electrode regions of the first and second conductivity type transistors.
An aspect of the present invention provides a manufacturing method of a semiconductor device that includes depositing a hard mask material on a gate electrode material, forming a dummy gate pattern on the deposited hard mask material, depositing a material for forming a sidewall around the dummy gate pattern, etching the material for forming the sidewall while the sidewall is left, selectively removing the dummy gate pattern, depositing resist, by lithography, to form a region coupling a gate electrode with a metal wiring, processing a hard mask of a gate electrode region, removing the resist, and processing the gate electrode region using the hard mask.
Here, a first conductivity type and a second conductivity type are opposite to each other. In other words, if the first conductivity type is an n-type, the second conductivity type is a p-type, and if the first conductivity type is a p-type, the second conductivity type is an n-type.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing a layout of a semiconductor device according to a first embodiment.
FIG. 2 is a view showing a layout of a semiconductor device according to a second embodiment.
FIG. 3 is a view showing a layout of a semiconductor device according to a third embodiment.
FIG. 4 is a view showing a semiconductor device of a fourth embodiment, and specifically, a CMOS inverter layout using a FinFET.
FIG. 5 is a view showing a cross-section of the nFET or pFET in a I-I section of FIG. 4 .
FIG. 6 is a view showing a layout of a semiconductor device of a fifth embodiment, and is a layout where the three-way NAND gate is formed by using FinFET.
FIG. 7 is a top view for describing that device regions are formed on the upper side of a device isolation region.
FIG. 8 is a view showing a cross-section in a II-II section of FIG. 7 .
FIG. 9 is a sectional view where a gate insulator 123 is formed on top of the cross-section in the II-II section shown in FIG. 7 .
FIG. 10 is a top view where polysilicon film is formed on the upper side of the device isolation region 120 .
FIG. 11 is a view showing a cross-section in a III-III section of FIG. 10 .
FIG. 12 is a top view where dummy patterns are formed after a film to be a material for a hard mask is formed.
FIG. 13 is a view showing a cross-section in a IV-IV section of FIG. 12 .
FIG. 14 is a top view where a film made of a material to form sidewalls around the dummy patterns is formed.
FIG. 15 is a view showing a cross-section in a V-V section of FIG. 14 .
FIG. 16 is a top view where RIE is performed while the sidewalls of the dummy patterns are left.
FIG. 17 is a view showing a cross-section in a VI-VI section of FIG. 16 .
FIG. 18 is a sectional view where the dummy patterns 126 are removed from the cross-section in the VI-VI section of FIG. 16 .
FIG. 19 is a top view where a resist pattern is formed.
FIG. 20 is a view showing a cross-section in a VII-VII section of FIG. 19 .
FIG. 21 is a top view where resist patterns are formed.
FIG. 22 is a view showing a cross-section in a VIII-VIII section of FIG. 21 .
FIG. 23 is a top view where RIE is performed to the polysilicon film 124 .
FIG. 24 is a view showing a cross-section in a IX-IX section of FIG. 23 .
FIG. 25 is a view where the resist region is removed from the cross-section in the IX-IX section of FIG. 23 .
FIG. 26 is a view showing a cross-section in a IX-IX section of FIG. 23 .
FIG. 27 shows an example of layout of an inverter chains according to an embodiment.
FIG. 28 is a sectional view where the contact regions and the wiring regions 130 are provided in the section of FIG. 26 .
FIG. 29 shows an example of a typical layout of a complementary metal oxide semiconductor inverter chain made up of conventional MOSFETs.
DETAILED DESCRIPTION OF EMBODIMENTS
Various embodiments of the present invention will be described with reference to the accompanying drawings. It is to be noted that the same or similar reference numerals are applied to the same or similar parts and devices throughout the drawings, and the description of the same or similar parts and devices will be omitted or simplified.
FIG. 1 is a view showing a layout of a semiconductor device according to a first embodiment. In this semiconductor device, two device regions (dotted regions in the drawing) are respectively formed, and gate electrode regions 101 are provided thereon. The device regions 102 and 103 surrounded by the gate electrode regions 101 form a drain region 102 of an nFET and a drain region 103 of a pFET, respectively. Furthermore, the respective device regions not surrounded by the gate electrode regions 101 form source regions. Specifically, a region 104 which is the device region not surrounded by the gate electrode region 101 forms a source region 104 of the nFET, while a region 105 which is the device region not surrounded by the gate electrode region 101 forms a source region 105 of the pFET. The source region 104 of the nFET is coupled to a ground wiring 107 through a contact region 108 a . The source region 105 of the pFET is coupled to a power supply wiring 106 through a contact region 108 b . A plurality of wirings 111 disposed in the center of the drawing are coupled to the drain regions 102 of the nFETs through contact regions 108 c and to the drain regions 103 of the pFETs through contact regions 108 d . In addition, the wirings 111 are coupled to the gate electrode regions 101 through pads 109 .
Thus, in the semiconductor device of the present embodiment, the gate electrode region 101 is formed by the sidewall pattern transfer method. Therefore, the gate electrode region 101 is formed in a loop shape. Moreover, the pad 109 is disposed onto part of the loop-shaped gate region as a connection region to connect the gate region with the metal wiring. Additionally, inverter chains are formed in the semiconductor device of this embodiment. As a consequent, each inverter shares the source region 104 or 105 with the inverter in the next stage.
Since the semiconductor device has such a structure, if the area of the drain region is the same as that of a conventional type, an electric current to drive junction capacitance per unit area is twice as large as that of a conventional MOSFET. Therefore, switching delay time can be improved. Moreover, since a mechanical strength of the gate can be improved by forming the gate in a loop-shape, the pattern of the ultra-fine gate region 101 can be prevented from falling down. Furthermore, since two gate electrodes are connected in parallel, parasitic resistance of the gate electrodes can be reduced. In addition, a MOSFET suitable to a gate electrode forming process employing the sidewall pattern transfer method can be formed using the loop-shaped gate electrode.
In this way, the drain region is formed inside the region surrounded by the gate electrode region connected in a loop-shape. That is, the drain region is formed inside the loop-shaped gate electrode. Thus, contribution of the junction capacitance can be seemingly reduced, which contributes to speeding-up of the semiconductor device.
Here, the configuration of the loop-shaped gate electrode region forming the nFET and that of the loop-shaped electrode region forming the pFET, as well as the configuration of the device region of the nFET and that of the device region of the pFET may be asymmetrical to each other, respectively. When the asymmetrical gate and device configurations are employed, a ratio between effective channel widths of the nFET and pFET can be adjusted.
Meanwhile, the source region is formed outside the region surrounded by the gate electrode region connected in the loop-shape. That is, the source region is arranged outside the gate electrode. Thus, a structure where an electric current as large as that of an ordinary MOSFET is applied is available. Alternatively, a structure where an electric current twice as large as that of the ordinary MOSFET is applied to the drain per unit area is available.
The regions connected in the loop-shapes that are the gate electrode regions may be formed so that the lengths thereof are the same on the device regions and a device isolation region.
Moreover, the gate electrode region of the pFET and that of the nFET may be coupled to each other through a region made of a same material as one forming these regions. Examples of the material include polysilicon and self-aligned silicide (salicide).
Furthermore, the substrate of the semiconductor device of the present invention may be a bulk substrate or a silicon-on-insulator (SOI) substrate.
In the case of the inverter chains of FIG. 1 , a region corresponding to the device isolation region 210 of FIG. 29 illustrating a conventional technology can be omitted. Therefore, if a source region length (channel length direction) is Ls′ and a drain region length (channel length direction) is Ld′, the area occupied by one CMOS inverter is proportional to Ls′/2+Ls′/2+Ld′=Ls′+Ld′. Accordingly, depending on a design rule, even when an inequality Ls<Ls′ or Ld<Ld′ is true, the layout can be one where an area equivalent to the device isolation region is reduced. This also contributes to higher integration of the semiconductor device.
Moreover, in the technology described in Technical Literature 1, one closed loop gate region serves as one gate. Specifically, in FIG. 1 of the foregoing Technical Literature 1, only one line of one closed loop becomes a gate. The present embodiment is different in that two lines of one closed loop serve as the gates. Therefore, there is an effect that the layout area can be made smaller.
FIG. 2 is a view showing a layout of a semiconductor device according to a second embodiment. The layout shown by the second embodiment is a layout of a three-way NAND gate. In this semiconductor device, a plurality of device regions 104 are formed on the right side of the drawing and a device region 105 is formed on the left side thereof. A plurality of gate electrode regions 101 are provided on these device regions. The device regions 102 and 103 surrounded by the gate electrode regions 101 form a drain region 102 of the nFET and a drain region 103 of the pFET, respectively. In addition, each of regions that are device regions not surrounded by the gate electrode regions 101 forms a source region. Specifically, the region 104 not surrounded by the gate electrode region 101 forms the source region 104 of the nFET, and the region 105 not surrounded by the gate electrode region 101 forms the source region 105 of the pFET.
The source regions 104 of the nFET are coupled to a ground wiring 107 through contact regions 108 a . Further, the source regions 105 of the pFETs are respectively coupled to a power supply wiring 106 through contact regions 108 b . Wirings 111 a and 111 b are coupled to the source regions 104 of the nFETs through contact regions 108 c , and coupled to the drain regions 102 of the nFETs through contact regions 108 d . Moreover, a wiring 111 c is coupled to three drain regions of the pFETs through contact regions 108 e , and coupled to the drain region 102 of the nFET through a contact region 108 f . A plurality of wirings 111 d connecting the gate electrode regions of the pFETs with the gate electrode regions of the nFETs are coupled to the gate electrode regions 101 through pads 109 . Three wiring regions 113 are coupled to the wirings 111 d through via regions 112 .
In the three-way NAND gate circuit, the adjacent nFETs are connected in series and the adjacent pFETs are connected in parallel. In FIG. 2 , the source regions 105 of the pFETs between the adjacent pFETs are connected and shared therebetween. However, the source regions 105 can be separated to be two adjacent regions with a device isolation region interposed therebetween. Moreover, as for the nFET, due to the circuit configuration, MOSFETs are not connected and each of which has two source regions 104 and one drain region 102 .
Here, a metal wiring layer other than the ones coupled to the drains may be disposed above the drain regions. Thus, a wiring against the gate electrode can be laid above the drain regions, whereby gate resistance can be reduced.
An input to the three-way NAND gate is coupled to the gate electrode 101 through the wiring 113 which is a wiring of a second layer, the via region 112 , the wiring 111 d which is a first metal wiring layer, and the pad 109 . Further, in this case, an output from a drain electrode region of the nFET is inputted to two points in the source region of the nFET in the next stage. Moreover, a NOR-type logic gate circuit can be formed by switching the nFET with pFET based on the layout of FIG. 2 . Therefore, it is possible to form a gate electrode using the sidewall pattern transfer technology even in the NOR circuit.
FIG. 3 is a view showing a layout of a semiconductor device according to a third embodiment. Specifically, this drawing shows a layout of pair MOSFET devices of a common gate used for some of current mirror-type differential amplifiers or the like. In this embodiment, a plurality of device regions surrounded by a gate region 101 are separately disposed. The device regions 102 a and 102 b surrounded by the gate electrode region 101 form drain regions 102 a and 102 b of the nFET. On the other hand, regions not surrounded by the gate electrode region 101 form source regions 104 a and 104 b of the nFET. The source regions 104 a and 104 b of the nFET are coupled to a ground wiring 107 through contact regions 108 a and 108 b . Moreover, wirings 111 a and 111 b are coupled to the drain regions 102 a and 102 b of the nFET through contact regions 108 c and 108 d , respectively. A wiring 113 is coupled to the gate electrode region 101 through a pad 109 .
Thus, this semiconductor device includes two drain regions 102 separated inside the loop-shaped gate electrode region 101 . These drain regions 102 are coupled to respective different output terminals. The source regions 104 may have a common electric potential or have respective different electric potentials. The electric potential can be changed by changing a way of connecting the metal wiring 107 . In this way, a fine gate length with which a gate electrode can be created by sidewall pattern transfer can be realized.
FIG. 4 is a view showing a semiconductor device of a fourth embodiment, and specifically, a CMOS inverter layout using a FinFET. The FinFET is one of three dimensional MOSFETs and utilizes as a channel side portion of a device region thinly cut out into oblong strips.
In this semiconductor device, a plurality of device regions 114 a and 114 b each of which includes a plurality of rectangular strip Fins are respectively formed. Gate electrode regions 101 are provided on these device regions. Device regions 102 and 103 surrounded by the gate electrode regions 101 form a drain region 102 of the nFET and a drain region 103 of the pFET, respectively. Further, regions 104 and 105 not surrounded by the gate electrode regions 101 form a source region 104 of the nFET and a source region 105 of the pFET, respectively. The source region 104 of the nFET is coupled to a ground wiring 107 through a contact region 108 a , while the source region 105 of the pFET is coupled to a power supply wiring 106 through a contact region 108 b . A wiring 111 is coupled to the drain region 102 of the nFET through a contact region 108 c and to the drain region 103 of the pFET through a contact region 108 d . Moreover, the wiring 111 is coupled to the gate electrode region 101 through a pad 109 .
As shown above, in the semiconductor device of the present embodiment, a plurality of device regions each including rectangular strip Fins are provided. Thus, the channel region of the device is formed in a plane perpendicular to a substrate, and a flowing direction of an electric current is horizontal to the substrate.
Here, when processing the substrate, a height at which the substrate is cut out may be limited due to a restriction on a process such as RIE. The height is typically on the order of several tens nm to 1 μm or less. However, a height outside the above range may be adopted. To obtain an electric current sufficient to drive an external load, it is preferable to form channel regions constituted of a plurality of Fins.
Meanwhile, in the device regions, it is preferable to provide relatively wide active regions in portions other than the channel portions in order to leave spaces for the contact regions. Thus, by adopting the layout shown in FIG. 4 , a logic circuit can be formed by using the sidewall pattern transfer method even when the FinFET is employed. The sidewall pattern transfer technology is also used when forming the Fin of the FinFET. Hence, ultra-fine Fin is formed. It is clear that this kind of layout is preferable to reduce drain junction capacitance of the relatively wide active regions as in the case of FIG. 1 .
Here, a single source region, a single drain region and a plurality of channel regions formed in a plane perpendicular to the substrate may be formed, a flowing direction of an electric current is horizontal to the substrate, and the channel regions may be depleted during operation.
Further, a ratio β of effective channel widths of the nFET and pFET (=Wp/Wn) can be changed by changing the number of Fins in the case of FinFET. That is:
Wp =(height of Fin)*2*(number of Fins of pFET)
Wn =(height of Fin)*2*(number of Fins of nFET)
Here, if the heights of the Fins are the same, the ratio of the effective channel widths will be a ratio of the number of Fins of the pFET to the number of the Fins of the nFET.
As a result, since a β value suitable to an inverter and a β value suitable to a later-described NAND gate or the like are different, it is required to make a layout where the numbers of Fins are different according to circuits therein.
Here, a dummy Fin that is not intended to be used may be formed in view of uniformity in a lithography process and in an RIE process. Specifically, when forming a Fin, on both sides of the Fin to be used, one or several Fins having a similar shape to the Fin to be used are formed. In this way, the foregoing uniformity in the lithography and RIE processes can be realized. Moreover, damage to the devices attributable to excessive polishing during chemical mechanical polishing (CMP) can be born by the dummy Fins formed on both sides of the Fin actually used. Thus, the damage to the Fin due to the excessive polishing can be prevented.
FIG. 5 is a view showing a cross-section of the nFET or pFET in a I-I section of FIG. 4 . This semiconductor device includes a buried oxide (BOX) region 116 on a substrate region 117 and a plurality of Fin regions 114 on the buried oxide region 116 . A cap insulator film region 115 is provided on each of the Fin region to insulate the top surface of the Fin region. In addition, the gate electrode region 101 is provided to cover the Fin regions 114 and the cap insulator film regions 115 . A predetermined region between the buried oxide region 116 and the gate electrode region 101 is provided as a device isolation region 110 that isolates the buried oxide region 116 from the gate electrode region 101 .
In this manner, a structure where channels are formed only in a plane perpendicular to the substrate and not on the top surfaces of the Fins can be made in the case of the FinFET. Thus, a so-called double-gate MOSFET device, which has an immunity for the short channel effect, can be formed. In this case, in the gate electrode region, the channels are formed in the plane perpendicular to the substrate. Further, in a region sandwiched between the device isolation regions, the channel portions and the gate electrode regions are alternately formed. A wide connection portion to connect the metal wiring portion with the source and drain regions with respect to each Fin of the FinFET makes a large region, and no device isolation region is formed therein. Moreover, the pad portion of the gate electrode portion is formed on the device isolation region.
FIG. 6 is a view showing a layout of a semiconductor device of a fifth embodiment, and is a layout where the three-way NAND gate is formed by using FinFET.
In this semiconductor device, device regions 114 a and 114 b each of which includes a plurality of rectangular strip Fins are respectively formed. Gate electrode regions 101 are provided on these device regions. Device regions 102 and 103 surrounded by the gate electrode regions 101 form a drain region 102 of the nFET and a drain region 103 of the pFET, respectively. In addition, each device region not surrounded by the gate electrode region 101 forms a source region. Specifically, regions 104 and 105 not surrounded by the gate electrode regions 101 form a source region 104 of the nFET and a source region 105 of the pFET, respectively. Three sets of the above formations are provided.
Two of the source regions 104 of the nFET are coupled to a ground wiring 107 through contact regions 108 a . Moreover, the source regions 105 of the pFET are respectively coupled to a power supply wiring 106 through contact regions 108 b . Wirings 111 a and 111 b are coupled to the source regions 104 of the nFETs through contact regions 108 c and to the drain regions 102 of the nFETs through contact regions 108 d . A wiring 111 c is coupled to the three drain regions 103 of the pFETs through pads 109 and to the drain region 102 of the nFET through a contact region 108 f . Moreover, a plurality of wirings 111 d connecting the gate electrode regions of the pFETs with the gate electrode regions of the nFETs are coupled to the gate electrode regions 101 through the pads 109 . Three wiring regions 113 are coupled to the wirings 111 d through via regions 112 to be coupled to the gate electrode regions 101 . In this embodiment, a plurality of the via regions 112 are provided. Further, each of the three wiring regions 113 is coupled to the wiring loll through the two via regions 112 .
In the case of this embodiment, the wiring regions 113 are coupled to the gate electrodes 101 at a plurality of points through the via regions 112 and the contact regions. Therefore, parasitic resistance of the gate electrode can be reduced, whereby switching delay time is improved. Moreover, in this embodiment, the wiring regions 113 are placed on top of the drain regions. Accordingly, a plurality of contact regions coupled to the gate electrodes can be provided with almost no increase in the layout area. As a consequence, lower resistance can be achieved. In addition, the adjacent source regions of the pFETs can be made into one region to be shared as in the case of the NAND gate circuit in FIG. 3 , whereby the device isolation region can be omitted. Furthermore, a similar layout to the one in FIG. 6 described in this embodiment can be applied to a NOR circuit where the nFET and pFET of FIG. 6 are switched.
Manufacturing Method of A Semiconductor Device
Next, a manufacturing method of a semiconductor device according to an embodiment will be described with reference to the drawings. In this embodiment, one example of manufacturing method of a CMOS, which has the layout of the semiconductor device described in detail in FIG. 1 , will be described in order.
FIG. 7 is a view for describing that device regions are formed on the upper side of a device isolation region. First, device regions 122 are formed on the upper side of a device isolation region 120 . In this embodiment, two device regions are formed. Then, gate oxide film (not shown) is formed on the top surfaces of the device regions.
FIG. 8 is a view showing a cross-section in a II-II section of FIG. 7 . As shown in the drawing, the device regions 122 are formed on the upper side of the device isolation region 120 .
FIG. 9 is a sectional view where a gate insulator 123 is formed on top of the cross-section in the II-II section shown in FIG. 7 . As shown in the drawing, the gate insulator 123 is formed on the top surfaces of the device regions 122 . Here, the gate insulator includes a gate oxide film (for example, SiO 2 ) and a high-dielectric-constant film. However, if chemical vapor deposition (CVD) is employed to form the high-dielectric-constant film, the gate insulator will be formed also on the sidewalls of the silicon nitride films 122 .
FIG. 10 is a view where polysilicon film is formed on the upper side of the device isolation region 120 . The gate insulator (not shown) is formed on top of the device isolation region 120 where the device regions 122 are formed. Thereafter, a polysilicon film 124 to serve as a gate electrode is formed. Here, a material used for the polysilicon film 124 includes polysilicon germanium, a stacked structure of polysilicon and polysilicon germanium or the like.
FIG. 11 is a view showing a cross-section in a III-III section of FIG. 10 . As shown in the drawing, the device regions 122 are formed on the upper side of the device isolation region 120 , and the gate insulator 123 is formed on the top surfaces of the device regions 122 . On top of that, the polysilicon film 124 to be gate electrode is then formed. In this drawing, the upper surface of the polysilicon film 124 is flat. However, the film may not be flat like this in an actual case. Here, the polysilicon film 124 is shown as a flat film for convenience of illustration.
FIG. 12 is a top view where dummy patterns are formed after a film to be a material for a hard mask is formed. In this process, onto the polysilicon film (not shown), the hard mask material 125 and also a material 126 having a high etching selective ratio relative to the hard mask material are sequentially deposited. Here, a stacked layer structure of SiO 2 and SiN can be adopted for the hard mask material. Moreover, tetraethyl orthosilicate tetraethoxysilane (TEOS) can be used for the hard mask material and material having the high selective etching ratio relative to the hard mask material. Thereafter, the dummy patterns 126 are formed by patterning the TEOS layer by lithography.
FIG. 13 is a view showing a cross-section in a IV-IV section of FIG. 12 . As shown in the drawing, the hard mask material 125 and also the material having the high selective etching ratio relative to the hard mask material are sequentially deposited onto the polysilicon film 124 . Then, the dummy patterns 126 are formed by patterning.
FIG. 14 is a top view where a film made of a material to form sidewalls around the dummy patterns is formed. In this process, after the dummy patterns are formed, the film of the material 127 to form the sidewalls around the dummy patterns is formed. Here, for example, amorphous silicon can be used for the material 127 .
FIG. 15 is a view showing a cross-section in a V-V section of FIG. 14 . As shown in the drawing, after the dummy patterns 126 are formed, the film made of the material 127 to form the sidewalls around the dummy patterns 126 is formed.
FIG. 16 is a top view where RIE is performed while the sidewalls of the dummy patterns are left. In this process, RIE is performed to the material 127 with the sidewalls left, whereby the amorphous silicon sidewalls are formed around the dummy patterns 126 .
FIG. 17 is a view showing a cross-section in a VI-VI section of FIG. 16 . As shown in the drawing, the sidewall materials 127 are formed on the sidewalls of the dummy patterns 126 .
FIG. 18 is a sectional view where the dummy patterns 126 are removed from the cross-section in the VI-VI section of FIG. 16 . As shown in the drawing, regions that have been the dummy patterns 126 are removed by selective etching, and the materials 127 provided as the sidewalls are left.
FIG. 19 is a top view where a resist pattern is formed. In this process, the TEOS regions which have been the dummy patterns are selectively etched. Then, the left amorphous sidewall regions 127 are used as masks to transfer patterns to the SiN hard mask. Here, the mask material is processed by RIE.
FIG. 20 is a view showing a cross-section in a VII-VII section of FIG. 19 . As shown in the drawing, the materials 125 are left at predetermined portions by a patterning process using the sidewall materials 127 as masks. If a fine line gate electrode is required, a process to reduce the dimension of the material 125 can be added.
FIG. 21 is a top view where resist patterns are formed. In this process, portions to be the contact regions of the gate electrodes are patterned using the resist.
FIG. 22 is a view showing a cross-section in a VIII-VIII section of FIG. 21 . Since part of the hard mask patterns of the gate electrodes need to contact with the contact regions of the gate electrodes, the part are to be covered by the resist regions 128 . In this example, each of the contact regions 128 simultaneously covers the gate electrodes on the left and right sides thereof. However, the contact region 128 may be provided to each of the gate electrodes and later connected with each other by the metal wirings.
FIG. 23 is a top view where RIE is performed to the polysilicon film 124 . In this process, the polysilicon film of the gate electrode is processed by RIE using the resist pattern made up of the SiN 125 and contact regions. Thus, a configuration as shown in the drawing is obtained.
FIG. 24 is a view showing a cross-section in a IX-IX section of FIG. 23 . Here, the SiN 125 to serve as the hard masks and the resist region 128 are used as a mask to process the polysilicon region 124 by RIE, and thus a configuration as shown in the drawing is obtained.
FIG. 25 is a view where the resist region is removed from the cross-section in the IX-IX section of FIG. 23 . Here, the SiN and the resist region are removed from the top surface of the polysilicon film. Thus, a sectional configuration as shown in the drawing is formed. It goes without saying that, on other cross-sections, the polysilicon film exists on the device regions 122 with the gate insulator interposed therebetween.
FIG. 26 is a view showing a cross-section in a IX-IX section of FIG. 23 . As shown in the drawing, an interlayer dielectric 129 is formed after ordinary manufacturing processes of a MOSFET (ion implantation into an S/D extension, gate sidewall forming, ion implantation into an S/D region, activation, salicide process and the like) are performed subsequent to the above processes.
After wiring the metal wirings as shown in FIG. 27 , inverter chains are finally formed in this case. FIG. 28 is a sectional view where the contact regions and the wiring regions 130 are provided in the section of FIG. 26 . Here, the contact regions and the wiring regions 130 for electrical connection are provided to the polysilicon film 124 b in the interlayer dielectric 129 and to the silicon nitride films 122 .
In this embodiment, silicon nitride, TEOS and amorphous silicon are used as the materials for the hard mask material 125 , the dummy pattern 126 and the sidewall material 127 , respectively. However, the materials are not limited to this combination. For example, the combination of the materials for the hard mask material 125 , dummy pattern 126 and sidewall material 127 may be silicon nitride-TEOS-amorphous silicon, silicon nitride-TEOS-amorphous silicon germanium, TEOS-amorphous silicon germanium-silicon nitride or the like.
The manufacturing process is not limited to the above method, and the order of some of the processes can be changed. In addition, here, the semiconductor device is limited to the one having a simple rectangular device region. However, the semiconductor device can be formed by a similar process even when the device region has a device form including a plurality of Fins.
Thus, according to the manufacturing method of the semiconductor device of the present embodiment, the loop gate electrode region is formed by the sidewall pattern transfer method. Therefore, when the area of the drain region is the same as that of the conventional type, the electric current to drive the drain junction capacitance is twice as large as that of the conventional MOSFET. Thus, switching delay time can be improved. Moreover, the mechanical strength can be increased by making the gate into a loop shape. Accordingly, it is possible to prevent the pattern of the ultra-fine gate region 101 from falling down. Moreover, since the two gate electrodes are connected in parallel, parasitic resistance of the gate electrode can be reduced. Furthermore, by employing the loop gate electrode, a MOSFET suitable to a gate electrode forming process adopting the sidewall pattern transfer method can be achieved.
As described above, according to the semiconductor device and the manufacturing method of the same of the present invention, it is possible to provide a semiconductor device and a manufacturing method of the same where a logic circuit can be formed even when a fine gate forming process adopting the sidewall pattern transfer method is employed.
The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the present invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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A semiconductor device includes a first device region including a plurality of source regions and a plurality of drain regions of first conductivity type transistors, a plurality of loop-shaped gate electrode regions of the first conductivity type transistors, a second device region including a plurality of source regions and a plurality of drain regions of a second conductivity type transistors, a plurality of loop-shaped gate electrode regions of the second conductivity type transistors, a first wiring configured to supply a first voltage to at least one of the source regions of the first device region, a second wiring configured to supply a second voltage to at least one of the source regions of the second device region, and a third wiring electrically coupled to the drain regions of the first and second device regions and to the gate electrode regions of the first and the second conductivity type transistors.
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TECHNICAL FIELD
The present invention is directed to a double alkali process employing limestone to regenerate spent sodium sulfite and to recirculate the unreacted limestone to thereby attain a high internal stoichiometry and high limestone utilization.
BACKGROUND OF THE PRIOR ART
An aqueous solution of sodium sulfite is often used in a countercurrent absorption tower to absorb sulfur dioxide from flue gas according to the following reaction:
(1) Na 2 SO 3 +H 2 O+SO 2 →2NaHSO 3
If oxygen is also present in the gas stream (such as flue gases) some sulfite is oxidized to sulfate.
(2) 2Na 2 SO 3 +O 2 →2Na 2 SO 4
The spent absorbent contains an aqueous solution of NaHSO 3 , Na 2 SO 4 and Na 2 SO 3 .
To regenerate the sodium sulfite the spent absorbent is reacted with calcium carbonate.
The primary reactions, shown below, take place in the regenerators external from the absorber loop so that solids do not enter the absorber.
(3) 2NaHSO 3 +CaCO 3 →CO 2 +Na 2 SO 3 +CaSO 3 .1/2H 2 O+1/2H 2 O
(4) 4NaHSO 3 +Na 2 SO 4 +2CaCO 3 →3Na 2 SO 3 +CaSO 3 .1/2H 2 O.CaSO 4 .1/2H 2 O+CO 2 +H 2 O
Existing technology on regeneration of sodium sulfite in the U.S. employe, in the regenerators, lime. However, limestone is far less expensive than lime and reduces the regeneration cost. Japanese processes use limestone to regenerate sodium sulfite but the conditions do not maximize the amount of sodium sulfate coprecipitated by Reaction (4). To remove the sodium sulfate the Japanese FGD (flue gas desulfurization) plants use a costly sulfate removal process that requires sulfuric acid.
BRIEF SUMMARY OF THE INVENTION
The present invention provides high limestone utilization, high sulfite conversion, precipitation of sulfate as calcium sulfate at a rate equal to sulfate formation by oxidation, and removal of some of the magnesium in the limestone by coprecipitation with calcium as mixed crystals of sulfites and sulfates.
These and other advantages are brought about by carrying out the regeneration of the sodium sulfite in a plurality of reactors and separation of the slurry from the reactors in at least one hydroclone. The at least one hydroclone has two primary functions: one to promote the reaction of NaHSO 3 , which reduces the reactor volumes and reduces the temperature of conversion; and two, to reduce the concentration of the limestone overflow, thus increasing the limestone utilization.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more particularly described in reference to the drawings wherein:
FIG. 1 is a process diagram of one form of the invention employing four reactors and one hydroclone; and
FIG. 2 is a modified process diagram employing four reactors and three hydroclones.
DETAILED DESCRIPTION OF THE INVENTION
As hereinbefore set forth the present invention is for a process to economically (i.e. high reagent utilization) regenerate sodium sulfite using limestone as the reagent in relatively short resident time (2-3 hr) reactors (typically agitated, baffled vessels) where the temperature is similar to the spent absorbent (50°-55° C.) thereby eliminating the need for external heat.
Referring to FIG. 1 of the drawing, 10 designates a flue gas/SO 2 absorber, wherein flue gas containing SO 2 enters the bottom of the absorber as indicated by arrow 12 and flue gas stripped of its SO 2 content exists at the top of the absorber as indicated by directional arrow 14. A sodium carbonate scrubbing slurry enters the absorber as indicated by arrow 16 and the partially spent scrubbing slurry is removed from the sump 18 via line 22 and pump 24. A portion of the slurry removed from the sump 18 is redirected into the absorber along with makeup sodium carbonate via conduit 26. Another portion of the spent and partially spent absorbent is directed via conduit 28 into a first reactor vessel 30 which preferably is provided with an agitator, not shown, and suitable baffles to decrease the reaction time. Also directed into the reactor 1 is ground limestone via conduit 32 and unreacted limestone from the bottom of the hydroclone 34 via conduit 36 as to be more fully described hereinafter.
Overflow from the reactor #1, designated 30, flows by gravity into reactor 2 thence into reactors 3 and 4. From the reactor 4, the reacted slurry is pumped via conduits 40 and 42 and pump 44 to the inlet 46 of the hydroclone 34.
The underflow from the hydroclone, comprising a slurry consisting of mainly of unreacted limestone (particles sizes of 12-44 micron, is returned to the first reactor as hereinbefore set forth. The hydroclone overflow solids exiting the hydroclone via conduit 48 consists mainly of CaSO 3 .1/2H 2 O (particle size of 3-12 microns).
Some of the overflow is sent via conduit 50 to the last reactor, reactor 4. The amount of the overflow returned to reactor 4 is determined by a liquid level controller 52 connected to valve 54 in line 50. The remainder of the hydroclone overflow is directed to a thickener 56. The sludge from the thickner 56 is directed to a filter generally designated 58 and the overflow from the thickener 56 and the liquid withdrawn by the filter 58 are directed and utilized as part of the make up liquid for the absorber 10 via conduits 60, 62 and 64. The cake from the filter 58 comprises waste sludge.
Typically the sodium sulfite regeneration is carried out in a relatively short residence time of about 2 to 3 hours in the four reactors, illustrated in FIG. 1 where the temperature is about the temperature of the spent absorbent, that is, about 50°-55° C., where the composition of the spent absorbent is typically 3% wt NaHSO 3 , 2.2% wt Na 2 SO 3 , 12.5% wt Na 2 SO 4 .
Typically at the filter 58 the solids are concentrated at about 50% solids and the cake can be washed as illustrated to recover sodium salts. The wash water may be combined with the filtrate and returned to the absorber and the small amount of sodium lost in the discharged waste sludge is replaced with makeup sodium carbonate.
Table 1 contains data on test runs listing operating conditions, where high reagent utilization, efficient bisulfite conversion and high amounts of sulfate coprecipitate are achieved simultaneously.
Variations of the processes described in reference to FIG. 1 can incorporate differing numbers of hydroclones and reactors and a 4 reactor 3 hydroclone system is illustrated in FIG. 2. In FIG. 2, like equipment is provided with reference characters ending in -2 which correspond to that described in reference to FIG. 1. In FIG. 2, the 3 hydroclones designated 70, 72 and 74 are positioned between reactors 2 and 3; 3 and 4; and following reactor 4.
It will be noted that hydroclone 70 has its underflow directed to reactor 1 via conduit 76 and its overflow directed to reactor 2 as controlled by the liquid controller 78 and valve 80 or via conduits 82 and 84 to reactor 3.
The underflow from hydroclone 72 is directed to reactor 2 via conduit 86 and the overflow 88 is directed to reactor 4 via conduits 90 and 92 and/or to reactor 3 as controlled by liquid controller 94 and its connected valve 96.
Hydroclone 74 is like hydroclone 34 of the form of the invention illustrated in FIG. 1 in that of the overflow from the hydroclone is directed at least in part, via conduit 98 to the thickner 56-2 thence to the filter 58-2 , with the filtrate and washwater being directed via conduits 60-2, 62-2 and 64-2 to the absorber 10-2. Another portion of the overflow from the hydroclone 74 is directed to reactor 4 as controlled by liquid controller 100 and valve 102.
In this form of the invention, as in the form described in reference to FIG. 1, the hydroclones serve two important functions:
(1) They increase the internal limestone stoichiometry (defined as moles CaCO 3 /moles NaHSO 4 in the reactors) thereby promoting Reaction (4), the regeneration of Na 2 SO 3 . This permits reduced reactor volume and reduced temperature to achieve the same extent of conversion of NaHSO 3 to Na 2 SO 3 compared to a system without the hydroclones.
(2) Hydroclone's overflow which has a much lower concentration of CaCO 3 than the last reactor is the only stream sent to the dewatering system for ultimate disposal of the solids. This gives much higher limestone utilization than if no hydroclones were used.
The high ratio of Na 2 SO 4 /Na 2 SO 3 in the spend absorbent increases the extent of Reaction 5 so that a sufficient (about 7-9%) fraction of the Na 2 SO 4 is converted to CaSO 4 1/2H 2 O. For most FGD systems this rate of sulfate removal (as CaSO 4 1/2H 2 O) equals its formation by oxidation (Reaction 2). Therefore, no costly auxiliary step is needed for sulfate removal.
TABLE I__________________________________________________________________________OPERATING CONDITIONS AND LIMESTONE UTILIZATION TEMP. IN HSO.sub.3 LIME LIMESTONERUN REACTOR MG++ HSO.sub.3 CONCENTRATION REACTED STONE UTILIZA-NO. °C. (PPM) ABSORBER REACTOR 4 % SR TION, % f__________________________________________________________________________T-1 65 666 0.583 0.089 84.8 0.99 84.3 --T-2 70 450 0.491 0.068 86.1 1.18 81.1 8.4T-3 54 673 0.537 0.131 75.6 1.14 85.2 9.9T-4 55 660 0.542 0.130 76.0 1.19 82.7 7.9T-5 54 655 0.578 0.146 74.8 1.02 90.6 7.6__________________________________________________________________________ Remarks: 1. Data for Run T1 based on 1st eight hour period. 2. Bisulfite concentration in absorber for Runs T3, T4 and T5 were corrected for dilution because of fresh water used to slurry limestone. Runs T1 and T2 used centrate to slurry limestone so no correction factors was used. 3. Mg++ are based on average concentration for all reactors as reported i Table B1. 4. Only Run T5 used hydroclone to recover unreacted limestone. 5. Limestone SR is the moles limestone/moles SO.sub.2 fed. 6. f = mole % of reacted limestone that formed coprecipitated calcium sulfate. 7. The average concentration of Na.sub.2 SO.sub.4 was 1.0 molar.
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A double alkali process employs limestone to regenerate spent sodium sulfite and then recirculates the unreacted limestone to attain a high internal stoichiometry and high limestone utilization. The regeneration of the sodium sulfite is carried out in a plurality of reactors and separation of the slurry from the reactors is carried out in at least one hydroclone. The at least one hydroclone has two primary functions: one to promote the reaction of Na 2 SO 3 , which reduces the reactor volumes and reduces the temperature of conversion; and two to reduce the concentration of the limestone overflow, thus increasing the limestone utilization.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 09/942,247, filed Aug. 29, 2001, now U.S. Pat. No. 6,525,943, issued Feb. 25, 2003, which is a continuation of application Ser. No. 09/344,284, filed Jun. 30, 1999, now U.S. Pat. No. 6,297,960, issued Oct. 2, 2001, which claimed the benefit of U.S. Provisional Application No. 60/091,156 filed Jun. 30, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for providing heat sinks or heat spreaders for stacked semiconductor devices.
2. State of the Art
Semiconductor device packages or integrated circuit packages typically contain small integrated circuits on a silicon substrate, or the like, typically referred to as IC chips, or die or dice. Such IC dice come in an infinite variety of forms, including, for example, Static Random Access Memory (SRAM) dice, Synchronous DRAM (SDRAM) dice, Static Random Access Memory (SRAM) dice, Sequential Graphics Random Access Memory (SGRAM) dice, flash Electrically Erasable Programmable Read-only Memory (EEPROM) dice, and processor dice.
Packaged IC dice communicate with circuitry external to their packages through lead frames embedded in the packages. These lead frames generally include an assembly of leads that extend into the packages to connect to bond pads on the IC dice through thin wire bonds or other connecting means and extend from the packages to terminate in pins or other terminals that connect to the external circuitry. Exemplary conventional lead frames include paddle-type wire-bond lead frames, which include a central die support and leads which extend to the perimeter of IC dice and connect to the dice through thin wire bonds, Leads-Over-Chip (LOC) lead frames, having leads which extend over an IC die to attach to and support the die while being electrically connected to the die through wire bonds or other connecting means, and Leads-Under-Chip (LUC) lead frames, having leads which extend under an IC die to attach to and support the die from below while being connected to the die typically through wire bonds.
As with all conductors, the leads in lead frames have an inductance associated with them that increases as the frequency of signals passing through the leads increases. This lead inductance is the result of two interactions: the interaction among magnetic fields created by signal currents flowing to and from an IC die through the leads and magnetic fields created by oppositely directed currents flowing to and from ground (known as “self” inductance).
While lead inductance in IC packages has not traditionally been troublesome because traditionally slow signal frequencies have made the inductance relatively insignificant, the ever-increasing signal frequencies of state of the art electronic systems have made lead inductance in IC packages significant.
In an attempt to eliminate such problems, IC dice are being mounted on substrates, such as printed circuit boards, using flip-chip type mounting arrangements. This allows for a high density of mounting arrangements for the IC die in a small area and solder balls or conductive epoxy to be used for the connections between the IC die and the substrate. However, the high density of the IC die on the substrate with increased operating speeds for the IC die cause a great amount of heat to be generated in a small confined area which can be detrimental to the operation of the IC die and substrate as well as surrounding components. Such heat must be dissipated as effectively as possible to prevent damage to the IC die.
Various arrangements have been suggested for use in dissipating heat from IC dice on substrates.
U.S. Pat. No. 5,239,200 illustrates an apparatus for cooling an array of integrated circuit chips mounted on a substrate comprising a thermally conductive cooling plate which has a plurality of integral, substantially parallel, closed-end channels for the circulation of a cooling medium therethrough.
U.S. Pat. No. 5,379,191 is directed to an adapter for an integrated circuit chip which may be used in a package arrangement for the chip. The package may include a heat sink or heat spreader on the top of the chip.
U.S. Pat. No. 5,396,403 is directed to a heat sink assembly for a multi-chip module. A thermally conductive plate is bonded to integrated circuit chips on a multi-chip module by indium solder. The plate, in turn, is thermally coupled to a heat sink, such as a finned aluminum member by thermal paste.
U.S. Pat. No. 5,291,064 is directed to a packaged semiconductor device having a wired substrate. A plurality of semiconductor device chips are connected to the wiring substrate by the use of bumps. A heat sink is bonded through a high heat conductive bonding layer to a surface of each of the semiconductor device chips.
However, in each instance of the prior art discussed above, the IC die or semiconductor devices are installed on the substrate in a single layer for the cooling thereof.
A need exists for the cooling of semiconductor devices on a substrate where the substrates and devices are vertically stacked. In such an arrangement the dissipation of the heat from the conductor devices is of concern.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to an apparatus and method for providing heat sinks or heat spreaders for stacked semiconductor devices. Alignment apparatus may be include for the alignment of the stacked semiconductor devices. An enclosure may be used for the heat sink or heat spreader.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a first embodiment of the present invention;
FIG. 2 is a cross-sectional view of a second embodiment of the present invention;
FIG. 3 is a cross-sectional view of a third embodiment of the present invention;
FIG. 4 is a cross-sectional view of fourth embodiment of the present invention;
FIG. 5 is a top view of a heat transfer member of the present invention;
FIG. 6 is a top view of an alternative heat transfer member of the present invention;
FIG. 7 is a top view of an alternative heat transfer member of the present invention;
FIG. 8 is a top view of an alternative heat transfer member of the present invention;
FIG. 9 is a cross-sectional view of a fifth embodiment of the present invention;
FIG. 10 is a top view of the fifth embodiment of the present invention; and
FIG. 11 is a cross-sectional view of the sixth embodiment of the present invention.
The present invention will be better understood when the drawings are taken in conjunction with the description of the invention hereafter.
DESCRIPTION OF THE INVENTION
Referring to drawing FIG. 1, a first embodiment of the present invention is shown. The stacked assembly 10 having heat transfer members therewith is illustrated on a substrate 12 . The substrate 12 contains a plurality of apertures 14 therein in which the ends of alignment pins 16 are retained, such as using an interference fit, adhesive bonding, threaded connections, etc. The alignment pins 16 may be of any suitable material for use in the aligning of the substrates 12 having sufficient strength and heat conductivity, such as metal, high temperature plastic, etc. The substrate 12 further includes a plurality of circuit traces 18 thereon. Stacked on substrate 12 are a plurality of semiconductor device assemblies 100 , each assembly 100 including a semiconductor device or die 102 mounted on a substrate 104 having a plurality of circuits thereon connected to bond pads on the semiconductor device 102 . The substrate further includes a plurality of vias or circuits therein for connection to other adjacent substrates by suitable connections therewith. Such suitable connections may be made by the use of reflowed solder balls 106 . As illustrated, located between vertically adjacent assemblies 100 are heat transfer plates 50 . The heat transfer plates 50 are formed having apertures 52 therein through which alignment pins 16 extend and elongated slots 54 through which reflowed solder balls 106 extend to make contact with circuits on adjacent substrates 104 . The heat transfer plates 50 have a portion thereof in contact with the inactive surface of the semiconductor device 102 of the assembly 100 to transfer the heat therefrom during the operation of the semiconductor device 102 . If desired, a thermal grease may be applied to the inactive surface of the semiconductor device 102 and/or the portion of the heat transfer plate 50 which contacts the inactive surface of the semiconductor device 102 to facilitate the transfer of heat from the semiconductor device 102 . The elongated slots 54 have sufficient width to allow no electrical contact from the reflowed solder balls 106 extending therethrough. The reflowed solder balls 106 extending from the bottom surface of the substrate 104 of the lowest assembly 100 in the vertical stack electrically and mechanically contact circuit traces 18 on the upper surface of the substrate 12 . The alignment apertures 52 in the heat transfer plates 50 are typically circular to closely mate with the alignment pins 16 to align the heat transfer plates 50 on the substrate 12 which, in turn, aligns the assemblies 100 located between the heat transfer plates 50 on the substrate 12 .
To provide additional heat transfer from the upper semiconductor device 102 which has no heat transfer plate 50 associated therewith, a finned heat transfer member 60 having a plurality of fins 62 thereon and alignment apertures 64 therein is placed into contact with the inactive surface of the semiconductor device 102 . The fins 62 may be integrally formed on the heat transfer member 60 or may be secured thereto by any suitable means, such as welding, or the like. The fins 62 may extend in any desired direction of the heat transfer member 60 . The alignment apertures 64 are used to locate the heat transfer member 60 using alignment pins 16 secured to the substrate 12 . A thermal grease may be applied to the inactive surface of the semiconductor device 102 and/or a portion of the lower surface of the heat transfer member 60 to aid in heat transfer from the semiconductor device 102 . If desired, a heat transfer plate 50 (shown in dotted lines) such as described herein, may be used between upper semiconductor device 102 and heat transfer member 60 for additional heat transfer from the upper semiconductor device 102 . If desired, a thermal grease may be used between the upper semiconductor device 102 and the heat transfer plate 50 and the heat transfer member 60 .
Referring to drawing FIG. 2, a second embodiment of stacked assembly 20 of the present invention is illustrated. The second embodiment of stacked assembly 20 of the present invention being the same as the first embodiment of stacked assembly 10 of the invention except as described hereinafter. A plurality of assemblies 100 is vertically stacked on a substrate 12 having a plurality of circuit traces 18 on the upper surface thereof and alignment pins 16 extending therefrom. The heat transfer plates 50 in the second embodiment of the invention illustrated include a plurality of annular heat conductive members 108 therebetween which are retained on the alignment pins 16 between adjacent heat transfer plates 50 in the plurality of vertically stacked assemblies 100 . The annular heat conductive members 108 may be comprised of any suitable material, such as easily deformable metal, a reinforced heat conductive elastomeric material, such as silicon rubber, having an annular spirally wound spring 110 therein, etc. The annular heat conductive members 108 help to transfer heat from one heat transfer plate 50 to an adjacent heat transfer plate 50 and to the heat transfer member 60 to provide an additional heat transfer path for the stacked assemblies 100 .
Referring to drawing FIG. 3, a third embodiment of stacked assembly 30 of the present invention is illustrated. The third embodiment of stacked assembly 30 of the present invention is the same as the first and second embodiments of stacked assemblies 10 and 20 of the present invention except as described hereinafter. The stacked assembly 30 of the present invention includes a plurality of vertically stacked assemblies 100 connected to a substrate 12 being aligned thereon by alignment pins 16 . An additional heat transfer path for conducting heat from the individual semiconductor devices or dice 102 connected to substrates 104 is provided by the inclusion of heat transfer spacers 112 located between adjacent heat transfer plates 50 and the bottom of adjacent substrates 104 of assemblies 100 . The heat transfer spacers 112 may be of any suitable material, such as an easily deformable metal, silicon rubber, an annular elastomeric member filled with thermal grease, etc. In this manner, heat transfer from the semiconductor device 102 is provided by heat transfer plate 50 , heat transfer member 60 , annular heat conductive members 108 , and heat transfer spacers 112 to the ambient atmosphere and through heat transfer member 60 to the ambient atmosphere.
Referring to drawing FIG. 4, a fourth embodiment of stacked assembly 40 of the present invention is illustrated. The fourth embodiment of stacked assembly 40 of the present invention comprises vertically stacked assemblies 100 as described hereinbefore on substrate 12 using alignment pins 16 . The assemblies 100 are in contact with heat transfer plates 50 and heat transfer members 60 . If desired, annular heat transfer members 108 (shown in dotted lines) may be used as well as heat transfer spacers 112 (shown in dotted lines) as described hereinbefore for the transfer of heat from semiconductor devices or dice 102 during operation.
Referring to drawing FIG. 5, a heat transfer plate 50 is illustrated. The heat transfer plate 50 is generally rectangular in shape having alignment apertures 52 therethrough, and having elongated slots 54 therein. The heat transfer plate 50 may be of any desired thickness sufficient for the effective heat transfer from semiconductor device 102 (not shown) in contact therewith.
Referring to drawing FIG. 6, an alternative heat transfer plate 50 ′ is illustrated. The alternative heat transfer plate 50 ′ is generally shaped having the crossbars of the T's located at each end and the stems of the T's joined with alignment apertures 52 formed therein. In this manner, additional clearance for the reflowed solder balls 106 is provided.
Referring to drawing FIG. 7, another alternative heat transfer plate 50 ″ is illustrated. The heat transfer plate 50 ″ is generally circular in shape having alignment apertures 52 therein and elongated slots 54 formed therein. The circular shape of the heat transfer plate 50 ″ provides additional material for the transfer of heat away from the semiconductor device 102 (not shown) which contacts the plate 50 ″.
Referring to drawing FIG. 8, yet another alternative heat transfer plate 50 ′″ is illustrated. The heat transfer plate 50 is generally elliptical in shape having alignment apertures 52 therein and elongated slots 54 formed therein. The circular shape of the heat transfer plate 50 provides additional material for the transfer of heat away from the semiconductor device 102 (not shown) which contacts the plate 50 .
Referring to drawing FIG. 9, a fifth embodiment of stacked assembly 80 of the present invention is illustrated. The fifth embodiment of stacked assembly 80 includes a plurality of vertically stacked assemblies 100 . Each assembly 100 includes a semiconductor device 102 mounted on a substrate 104 as described hereinbefore. Each assembly 100 is electrically and mechanically connected to an adjacent assembly 100 by means of reflowed solder balls 106 extending therebetween. Each substrate 104 of the assembly 100 having circuits thereon, circuits therein, and vias extending therethrough, as required, to make electrical contact as required with the semiconductor device 102 . Surrounding each substrate 104 is a heat transfer member 150 . Each assembly 100 is contained or installed in, or has extending therearound, a heat transfer member 150 . The heat transfer member 150 comprises a member of suitable metal having downwardly extending retention T-shaped flanges 152 , upon a portion of which a substrate 104 sits, and upwardly extending L-shaped members 154 , the upper portion 156 serving as support for the assembly 100 located thereabove having a heat transfer member 150 located therearound. The upper portion 156 of L-shaped members 154 having an area 158 into which lower portion 160 of retention T-shaped flanges 152 extends to locate, position, and retain the heat transfer member 150 in position with respect to an adjacent heat transfer member 150 as well as locating and positioning the assembly 100 within the heat transfer member 150 with respect to an adjacent assembly 100 in its heat transfer member 150 .
Referring to drawing FIG. 10, an assembly 100 having heat transfer member 150 located therearound is illustrated. In addition to retention T-shaped flanges 152 and L-shaped members 154 retaining the assembly 100 in the heat transfer member 150 , additional L-shaped members 164 are used on the other sides of the heat transfer member 150 , not illustrated in drawing FIG. 9, to retain the substrate 104 of the assembly 100 in position in the heat transfer member 150 . Some of the additional L-shaped members 164 extend over or above the assembly 100 while other L-shaped members 164 extend therebelow to act as a ledge or support for the substrate 104 of the assembly 100 when it is installed in the heat transfer member 150 . As illustrated, the reflowed solder balls 106 extend in two rows along two portions of the substrate 104 .
Referring to drawing FIG. 11, a sixth embodiment of stacked assembly 180 of the present invention is illustrated. The sixth embodiment of stacked assembly 180 includes a plurality of assemblies 100 comprising substrates 104 having semiconductor devices 102 thereon, each substrate 104 being electrically and mechanically connected to an adjacent substrate 104 by reflowed solder balls 106 extending therebetween. The plurality of assemblies 100 are contained within an enclosure 170 having a plurality of vertical heat transfer fins 172 thereon and a plurality of horizontal heat transfer fins 174 extending thereacross. The lowermost assembly 100 is formed having substantially the same shape as opening 178 of the enclosure 170 so that the plurality of assemblies 100 may be retained therein, except for the bottom of the substrate 104 of the lowermost assembly 100 and the reflowed solder balls 106 thereon, and a seal 176 is used to sealingly engage the substrate 104 and enclosure 170 to form an enclosed, lead free member. The enclosure 170 may be made of any suitable material, such as metal, plastic, etc., and may be of any desired suitable geometric shape. Any desired number of heat transfer fins 172 and 174 may be used on the enclosure 170 . The heat transfer fins 172 and 174 may have any desired shape suitable for use on the enclosure 170 . The heat transfer fins 172 and 174 may be integrally formed on the enclosure 170 or attached thereto using any desired suitable attachment devices, such as adhesives, soldering, etc. Any desired number of assemblies 100 may be used in the enclosure 170 . The enclosure 170 may be filled with a suitable heat transfer fluid, such as thermal grease, oil, etc.
The present invention may include changes, additions, deletions and modifications which are within the scope of the invention.
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An apparatus for providing heat sinks or heat spreaders for stacked semiconductor devices. Alignment apparatus may be included for the alignment of the stacked semiconductor devices. An enclosure may be used as the heat sink or heat spreader.
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RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 10/025,425, filed Dec. 19, 2001, which claims the benefit of U.S. Provisional Application Serial No. 60/265,443, filed on Jan. 31, 2001, and said applications are herein incorporated by reference in their entirety.
FIELD OF THE INVENTION
The invention relates to a new process for preparing a scopine ester useful as an intermediate in preparing (1α,2β,4β,5α,7β)-7-[(hydroxydi-2-thienylacetyl)oxy]-9,9-dimethyl-3-oxa-9-azoniatricyclo[3.3.1.0 2,4 ]nonane-bromide.
BACKGROUND OF THE INVENTION
The compound (1α,2β,4β,5α,7β)-7-[(hydroxydi-2-thienylacetyl)oxy]-9,9-dimethyl-3-oxa-9-azoniatricyclo[3.3.1.0 2,4 ]nonane-bromide is known from European Patent Application EP 418 716 A1 and has the following chemical structure:
The compound has valuable pharmacological properties and is known by the name tiotropium bromide (BA679). Tiotropium bromide is a highly effective antichoinergic and can therefore provide therapeutic benefit in the treatment of asthma or COPD (chronic obstructive pulmonary disease).
Tiotropium bromide is preferably administered by inhalation. Suitable inhalable powders packed into appropriate capsules (inhalettes) may be used, which are administered using corresponding powder inhalers. Alternatively, it may be administered by the use of suitable inhalable aerosols. These also include powdered inhalable aerosols which contain, for example, HFA134a, HFA227 or mixtures thereof as propellant gas.
In view of its great efficacy, tiotropium bromide can be used in low therapeutic doses. On the one hand this imposes particular demands on the pharmaceutical production of the formulation to be used, and on the other hand it is particularly necessary to develop an industrial process for synthesising tiotropium bromide which ensures that the product is prepared not only in a good yield but also with exceptional purity.
European Patent Application EP 418 716 A1 discloses a method of synthesising tiotropium bromide. It corresponds to the method diagrammatically shown in Diagram 1.
Diagram 1
In a first step, scopine (II) is reacted with methyl di-(2-thienyl)-glycolate-(III) to form di-(2-thienyl)-glycolic acid scopine ester (IV), which is then quaternized to form tiotropium bromide.
DETAILED DESCRIPTION OF THE INVENTION
It has been found that, surprisingly, tiotropium bromide can be obtained in much purer form if it is synthesised by a different method from that described in EP 418 716 A1. This alternative and surprisingly more advantageous method is diagrammatically illustrated in Diagram 2.
Diagram 2
Starting from the tropenol (V) known in the art and reacting with di-(2-thieny)-glycolic acid derivatives (VI), first the tropenol di-(2-thienyl)-glycolate (VII) is formed. This is converted into the corresponding scopine ester (IV) by epoxidation of the olefinic double bond.
Accordingly, the present invention relates to a process for preparing tiotropium bromide (I)
characterised in that the tropenol ester of formula (VII)
is oxidised to form the scopine ester of formula (IV)
which is then quaternized with methyl bromide to form tiotropium bromide (I).
Because of the central importance of the tropenol ester of formula (VII) according to the invention, in another aspect, the present invention relates generally to the use of the tropenol ester (VII), optionally in the form of the acid addition salts thereof, for preparing tiotropium bromide (I). In another aspect, the present invention relates to the use of the tropenol ester (VII), optionally in the form of the acid addition salts thereof, for preparing the scopine ester of formula (IV).
When tropenol ester (VII) is used in the form of an acid addition salt for preparing the scopine ester (IV), this acid addition salt is preferably selected from among hydrochloride, hydrobromide, hydrogen phosphate, hydrogen sulphate, tetrafluoroborate and hexafluorophosphate; the hydrochloride and hydrobromide are particularly preferred.
According to another aspect, the present invention relates to a process for preparing tiotropium bromide of formula (I)
characterised in that in a first step tropenol of formula (V),
optionally in the form of the acid addition salts thereof, is reacted with an ester of formula (VI)
wherein R denotes a group selected from among hydroxy, methoxy, ethoxy, O—N-succinimide, O—N-phthalimide, phenyloxy, nitrophenyloxy, fluorophenyloxy, pentafluorophenyloxy, vinyloxy, —S-methyl, —S-ethyl and —S-phenyl, to form the tropenol ester of formula (VII)
which is then epoxidised in a second step to form the scopine ester of formula (IV)
and this is then quaternized in a third step using methylbromide to obtain tiotropium bromide (I).
Because of the central importance of the tropenol (V) as a starting material for preparing tiotropium bromide (I), in another aspect the present invention further relates to the use of tropenol (V), optionally in the form of the acid addition salts thereof, as a starting material for preparing tiotropium bromide (I).
To prepare the tropenol ester (VII), tropenol, optionally in the form of an acid addition salt thereof selected from among the hydrochloride, hydrobromide, hydrogen phosphate, hydrogen sulphate, tetrafluoroborate and hexafluorophosphate, preferably in the form of the hydrochloride or hydrobromide, most preferably in the form of the hydrochloride, is taken up in a suitable organic solvent, preferably in a solvent selected from among toluene, benzene, n-butylacetate, dichloromethane, THF, dioxane, dimethylacetamide, DMF and N-methylpyrrolidinone, preferably selected from among toluene, benzene, THF, dioxane, dimethylacetamide, DMF and N-methylpyrrolidinone, most preferably toluene or benzene, toluene being most particularly preferred as the solvent. According to the invention, 0.5-3 l, preferably 0.75-2.5 l, most preferably between 1.25 and 1.75 l of organic solvent are used per mol of tropenol (V) put in.
If tropenol is used in the form of an acid addition salt thereof, a base is added to the resulting mixture to liberate the tropenol. Suitable bases according to the invention are inorganic or organic bases, organic amines being particularly preferred. Organic amines which may be used include triethylamine, diisopropylethylamine, pyridine, dimethylaminopyridine, N-methylpyrrolidine, N-methylmorpholine or ammonia, the use of triethylamine, diisopropylethylamine, pyridine or ammonia being particularly preferred, while ammonia is most particularly preferred. At least 1 mol, preferably 1.25 to 2.5 mol, most preferably 1.5 to 2 mol of amine are added, per mol of tropenol salt used. The amine may be added at temperatures of between 0 and 60° C., preferably 15 to 50° C., most preferably 20 to 30° C. After the amine has been added, the suspension obtained is stirred at constant temperature for between 0.1 to 5 h, preferably between 0.5 to 2.5 h, most preferably between 0.75 and 1.5 h.
The ammonium salt thus obtained is filtered off and optionally washed with the organic solvent mentioned above. Between 0.1 and 1.5 l, preferably 0.3-1.0 l of solvent are used per mol of tropenol (V) put in.
Some of the solvent is distilled off in vacuo at elevated temperature, preferably at 30-80° C., most preferably at 40 to 60° C. The distillation temperature naturally depends on the choice of solvent used. Depending on the choice of solvent, the vacuum is adjusted so that distillation takes place in the temperature range specified above. Between 0.25 and 2 l, preferably 0.5-1.5 l of solvent are distilled off per mol of tropenol (V) put in. After the specified amount of solvent has been distilled off, the reaction solution is cooled to a temperature range of from 0-50° C., preferably to 15-35° C., and the di-(2-thienyl)glycolic acid derivative (VI) is added. Di-(2-thienyl)glycolic acid derivatives (VI) which may be used according to the invention are those compounds wherein R denotes hydroxy, methoxy, ethoxy, O—N-succinimide, O—N-phthalimide, phenyloxy, nitrophenyloxy, fluorophenyloxy, pentafluorophenyloxy, vinyloxy, —S-methyl, —S-ethyl or —S-phenyl. It is particularly preferred to use the compound (VI) wherein R denotes hydroxy, methoxy or ethoxy , most preferably methoxy or hydroxy. If the compound wherein R is hydroxy is used as the compound (VI), the reaction may be carried out in the presence of coupling reagents such as carbonyldiimidazole, carbonyldi-1,2,4-triazole, dicyclohexylcarbodiimide or ethyl-dimethylaminopropylcarbodiimide. Between 1 and 2 mol of compound (VI) are used per mol of tropenol (V) put in. Preferably, 1-1.5 mol of (VI) are used, and most preferably stoichiometric amounts of (VI) compared with (V) are used according to the invention. The reaction mixture obtained may optionally be heated to form a solution. A temperature in the range from 30-80° C., preferably from 40-60° C., most preferably about 45-55° C. is chosen.
The solution thus obtained is then added to another solution or mixture of an inorganic or organic base in one of the abovementioned solvents, preferably in the solvent which is used to prepare the mixture of (V) and (VI). Between 0.2 and 2.0 l, preferably 0.4-1.5 l, most preferably 0.5 to 1.0 l of solvent are used per mol of tropenol (V) put in, in order to prepare the solution or mixture containing a base. Where R equals methoxy, ethoxy, vinyloxy, phenyloxy, —S-methyl, —S-ethyl or —S-phenyl the reaction is carried out in the presence of an organic or inorganic base. The organic bases used are preferably organic amines, most preferably diisopropylethylamines, triethylamines, cyclic amines such as DBU or pyridine. Suitable inorganic bases are the alkali metal or alkaline earth metal carbonates, the alkoxides and hydrides of lithium, sodium, potassium, calcium such as sodium carbonate, lithium carbonate, potassium carbonate, calcium carbonate, sodium hydride, potassium hydride, calcium hydride, sodium methoxide, sodium ethoxide, potassium methoxide or potassium ethoxide. Most preferably, the inorganic base used is one of the abovementioned hydrides or alkoxides, preferably one of the abovementioned hydrides, the use of sodium hydride being particularly preferred according to the invention. At least stoichiometric amounts of base are used per mol of tropenol (V). Preferably, 1-3 mol, most preferably 1.25-2.5 mol, even more preferably 1.5 to 2 mol of base are used per mol of tropenol (V).
The solution of (V) and (VI) is combined with the base-containing solution or mixture described above, preferably over a period of 0.2-2.0 h, preferably over a period of 0.5 to 1.5 h. If an ester in which R denotes methoxy or ethoxy is used as the compound (VI), for example, it may be necessary to distil off the resulting alcohol at 40-90° C., preferably at 50 to 80° C., most preferably at 60-75° C. in vacuo, preferably at 150 to 500 mbar, most preferably at 200-350 mbar, particularly preferably at 250-300mbar. This procedure shifts the equilibrium of the reaction towards the tropenol ester (VII). Under these reaction conditions, some of the solvent is also distilled off. After the distillation is complete (about 5 to 10 h), the quantity of solvent distilled off can be added to the reaction solution if desired.
In any case, once distillation is complete, the solution obtained is cooled down again to a temperature range of below 40° C., preferably 0-35° C., most preferably 10-25° C. Hydrochloric acid is added to this mixture at constant temperature over a period of 0.2 to 2 h, preferably 0.4-0.6 h. The hydrochloric acid may be added either in the form of aqueous solutions or as a gas; the addition of aqueous solutions is preferred. Preferably, concentrated hydrochloric acid (36%) dissolved in water is added. Between 1 and 4 mol, preferably 1.5-3 mol, most preferably 2.0 to 2.5 mol HCl are preferably added per mol of tropenol (V) used. Preferably, 0.1-0.4 kg, most preferably 0.15-0.25 kg of 36% aqueous hydrochloric acid dissolved in 10-20 litres, preferably in 12-17 litres of water are added per mol of tropenol (V).
After everything has been added and the mixture has been thoroughly stirred the aqueous phase is separated off. It is then washed with a suitable water-immiscible organic solvent. The preferred solvent is a water-immiscible solvent selected from among methylene chloride and n-butylacetate, preferably methylene chloride. If desired, the first organic phase used to extract the aqueous phase is discarded and the extraction process is repeated once more.
The aqueous phase, optionally after previously being washed with one of the abovementioned water-immiscible solvents, is mixed once more with the water-immiscible solvent. Preferably 1-5 l, preferably 2-4 l, most preferably 2.5-3.5l of the water-immiscible solvent are used per mol of tropenol (V) originally put in. The mixture thus obtained is combined with an inorganic base, preferably selected from the alkali metal or alkaline earth metal carbonates of lithium, sodium, potassium, calcium such as, for example, sodium carbonate, lithium carbonate, potassium carbonate or calcium carbonate, sodium carbonate being particularly preferred, and thus adjusted to a pH of 7.5 to 11, preferably 8 to 10. The inorganic base is preferably added in the form of aqueous solutions. For example, according to the invention, it is particularly preferable to add 0.05 to 0.4 kg, preferably 0.1 to 0.2 kg of inorganic base dissolved in 0.25 to 1.5 l, preferably in 0.5 to 1 l, most preferably in 0.7 to 0.8 L of water per mol of tropenol (V) used.
After thorough mixing of the reaction mixture obtained, the aqueous phase is separated off and extracted one or more times with the water-immiscible solvent mentioned earlier. A total of 1-8 l, preferably 2-6 l, most preferably 3-5 l of the abovementioned water-immiscible solvent are used to extract the aqueous phase per mol of tropenol (V) originally used. The combined organic phases are subsequently freed from solvent by distillation at elevated temperature, preferably at 30-90° C., most preferably at 50-70° C. The temperature ranges specified above are highly dependent on the choice of solvent used, as will be apparent to anyone skilled in the art. If desired, a vacuum may also be applied for this distillative elimination of the solvent so as to keep the temperature within the temperature ranges defined hereinbefore. With solvents which are distilled off below the maximum temperature ranges defined above, the maximum distillation temperature will naturally be the boiling point of the solvent in question.
The residue remaining after distillation is taken up in an organic solvent. This solvent can be selected from among the solvents which may be used according to this specification to carry out the reaction of (V) and (VI) to form (VII). Preferably the same solvent is used as in this reaction. 1-5 l, preferably 1.5-4 l, preferably 2-3 l of solvent are used to dissolve the residue per mol of tropenol (V) originally used. The solution thus obtained is heated, to not more than the boiling temperature of the solvent, preferably to a range of from 50-100° C., most preferably 80-95° C. The heated solution is slowly cooled to a temperature in the range from −10° C. to 20° C., preferably 0-10° C. The tropenol ester (VII) is obtained in the form of colourless crystals which are separated off and dried. Drying is preferably carried out under inert gas at temperatures from 30-50° C.
The tropenol ester (VII) thus obtained is then epoxidised as described hereinafter to form the scopine ester (IV). A suitable solvent, preferably selected from among water, dimethylformamide, acetonitrile, dimethylacetamide and N-methylpyrrolidinone, most preferably dimethylformamide, is placed in a suitable reaction apparatus and heated to a temperature in the range from 30-70° C., preferably 40-60° C. 2-10 l, preferably 3-8l, preferably 4-7 l, most preferably 5-6 l of solvent are used per mol of tropenol ester (VII) used. The tropenol ester (VII) is added to the solvent which has been heated as described above and the resulting mixture is stirred at constant temperature until a clear solution is obtained.
An epoxidising agent is then added batchwise to this solution at a temperature in the range from 20-50° C., preferably at 35-45° C. The preferred epoxidising agent is preferably vanadium pentoxide mixed with H 2 O 2 , most preferably an H 2 O 2 -urea complex in combination with vanadium pentoxide. Preferably, the hydrogen peroxide urea complex and vanadium pentoxide are added batchwise alternately, most preferably water is also added. 0.1-0.5 kg, preferably 0.15-0.3 kg of hydrogen peroxide-urea complex, 0.1-1.0 l, preferably 0.15-0.7 l, most preferably 0.2-0.4 l water as well as 0.001-0.1 kg, preferably 0.005-0.05 kg, most preferably 0.01-0.025 kg of vanadium pentoxide are used per mol of tropenol ester (VII) used. After everything has been added, the mixture is stirred for a period of 1-6 h, preferably 1.5-4 h, preferably 2-3 h at a temperature of 30-70° C. preferably 40-60° C., most preferably 45-55° C.
It is then cooled to a temperature in the range from 10-30° C., preferably to 15-25° C. and adjusted to a pH of 2.5-5.5, preferably a pH of 3.5-4.5 with hydrochloric acid. The hydrochloric acid may be added either in the form of aqueous solutions or as a gas, the addition of aqueous solutions being preferred. Preferably, concentrated hydrochloric acid (36%) dissolved in water is added. After thorough mixing, an inorganic salt is added, preferably sodium hydrogen sulphite. This is preferably added in the form of aqueous solutions. Most preferably, 20-100 g, preferably 30-80 g, most preferably 40-60 g of inorganic salt dissolved in 0.1-1 l, preferably 0.3-0.7 l of water (in each case per mol of compound (VII) used) are added per mol of tropenol ester (VII) used. Some of the solvent is distilled off at an internal temperature of 20-50° C., preferably 30-40° C. About 2-8 l, preferably 3-6 l of the solvent is eliminated per mol of compound put in. After cooling to about 15-25° C. Clarcel (Celite) is added (in an amount of about 40-100 g, preferably 60-80 g per mol of compound (VII) put in). By again adding hydrochloric acid, preferably dilute aqueous hydrochloric acid, a pH of 1-3, preferably 1.5-2.5 is obtained. Preferably, 10-30 g, preferably 15-20 g of 36% hydrochloric acid, dissolved in 5-15 l, preferably 8-12 l of water (per mol of (VII) put in) are used per mol of compound (VII) used.
The solution obtained is filtered and optionally extracted one, two or three times with a suitable, water-immiscible solvent. Preferably, a water-immiscible solvent selected from among methylene chloride and n-butylacetate, preferably methylene chloride, is used. The organic phases used to extract the aqueous phase are discarded.
The aqueous phase is mixed once again with the water-immiscible solvent, optionally after previous washing with one of the water-immiscible solvents mentioned above. Preferably, 1-5 l, preferably 2-4 l, most preferably 2.5-3.5 l of the water-immiscible solvent are used per mol of tropenol ester (VII) originally put in. The resulting mixture is combined with an inorganic base, preferably selected from the alkali metal or alkaline earth metal carbonates of lithium, sodium, potassium or calcium, such as, for example, sodium carbonate, lithium carbonate, potassium carbonate or calcium carbonate, sodium carbonate being particularly preferred, and adjusted to a pH of 8 to 11, preferably 9 to 10.5. The inorganic base is preferably added in the form of aqueous solutions. For example and according to the invention, most preferably, 0.05 to 0.4 kg, preferably 0.15 to 0.3 kg of sodium carbonate dissolved in 0.25 to 2 l, preferably in 0.75 to 1.25 l are added per mol of ester (VII) used.
After thorough mixing of the reaction mixture obtained, the aqueous phase is separated off and extracted one or more times with the water-immiscible solvent mentioned earlier. A total of 1-5 l, preferably 2-4 l of the abovementioned water-immiscible solvent are used to extract the aqueous phase per mol of tropenol ester (VII) originally used. The combined organic phases are subsequently freed from solvent by distillation at preferably 25-50° C., most preferably at 30-40° C. The temperature ranges specified above are highly dependent on the choice of solvent used, as will be apparent to anyone skilled in the art. If desired, a vacuum may also be applied for this distillative elimination of the solvent so as to keep the temperature within the temperature ranges defined hereinbefore. Preferably, distillation is carried out under a slight vacuum at 500-800 mbar, preferably at 600-700 mbar. About 2-6 l, preferably 3-5 l of the solvent is distilled off per mol of the ester (VII) originally put in.
It may possibly be necessary to eliminate impurities in the form of secondary amines at this point. This is done, according to the invention, by using organic carboxylic acid halides, preferably acid chlorides selected from among acetyl chloride, propionic acid chloride or butyric acid chloride. Acetyl chloride is preferably used. Usually, between 5 and 30 g, preferably 10-20 g of carboxylic acid halide are used per mol of ester (VII) originally used. After the addition of the carboxylic acid halide at 15-25° C. the mixture is stirred for 15 minutes to 1.5 h, preferably between 30 and 45 minutes at constant temperature.
Then the mixture is brought to a temperature in the range from 10-30° C., preferably to 15-25° C., and adjusted to a pH of 1-3, preferably a pH of 1.5-2.5 with hydrochloric acid. The hydrochloric acid may be added either in the form of aqueous solutions or as a gas; it is preferably added as an aqueous solution. Preferably, concentrated hydrochloric acid (36%) dissolved in water is added. Preferably, 0.05-0.5 kg, preferably 0.075-1.25kg of 36% hydrochloric acid, dissolved in 5-15 l, preferably 8-12 l of water (per mol of (VII) used) are used per mol of compound (VII) put in. The organic phase is separated off and discarded.
The aqueous phase is mixed once again with the water-immiscible solvent, optionally after previous washing with one of the water-immiscible solvents mentioned above. Preferably 1-5 l, preferably 2-4 l, most preferably 2.5-3.5 l of the water-immiscible solvent are used per mol of tropenol ester (VII) originally put in. The resulting mixture is combined with an inorganic base, preferably selected from the alkali metal or alkaline earth metal carbonates of lithium, sodium, potassium or calcium, such as, for example, sodium carbonate, lithium carbonate, potassium carbonate or calcium carbonate, sodium carbonate being particularly preferred, and adjusted to a pH of 8 to 11, preferably 9 to 10.5. The inorganic base is preferably added in the form of aqueous solutions. For example and according to the invention, most preferably, 0.05 to 0.4 kg, preferably 0.1 to 0.2 kg of sodium carbonate dissolved in 0.25 to 2 l, preferably in 0.7 to 1.2 l are added per mol of ester (VII) used.
After thorough mixing of the reaction mixture obtained, the aqueous phase is separated off and extracted once or preferably twice with the water-immiscible solvent mentioned earlier. A total of 0.5-2.5 l, preferably 1-2 l of the abovementioned water-immiscible solvent are used to extract the aqueous phase per mol of tropenol ester (VII) originally used. The combined organic phases are subsequently freed from solvent by distillation at preferably 25-50° C., most preferably at 30-40° C. (about 1-3 l, preferably 1.5-2.5 solvent are eliminated per mol of ester (VII) used). A solvent selected from among dimethylformamide, dimethylacetamide, N-methylpyrrolidinone or dichloromethane, preferably dimethylformamide, is then added. Between 1 and 5 kg, preferably between 1.5 and 4 kg, most preferably between 2 and 3 kg of solvent are used per mol of ester (VII) put in. The remaining traces of the water-immiscible solvent used previously for extraction are distilled off from this solution under a slight vacuum (600-700 mbar) and at a temperature of 30-40° C. The solution of scopine ester (IV) thus obtained is used directly in the next step without any further isolation of the intermediate compound.
In order to prepare tiotropium bromide (I), methyl bromide is introduced into the scopine ester solution obtainable according to the instructions provided hereinbefore at 10-30° C., preferably at 15-25° C. As a solution of scopine ester (IV) is used in this step without any measurement of the yield of the preceding step, the quantities specified below relate to the tropenol ester (VII) originally put in. At least 1 mol of methylbromide is used per mol of scopine ester (IV). 0.1-0.2 kg, preferably 0.11-0.15 kg of methylbromide are preferably used according to the invention per mol of tropenol ester (VII) used. After all the methylbromide has been added the mixture is stirred at 15-35° C. for 1-3 days, preferably for 48-72 hours. Then the solvent dimethylformamide is partly distilled off in vacuo at 30-60° C., preferably at 45-55° C. The vacuum is selected so that the solvent is distilled off within the temperature ranges mentioned above. About 0.5-2.0 l, preferably 1.0-1.75 l of solvent are distilled off per mol of tropenol ester (VII) used and then cooled to about 5-20° C., preferably 10-15° C. At this temperature, the mixture is stirred until the crude product has fully crystallised and the crystals precipitated are separated off and dried at 30-50° C. under inert gas, preferably nitrogen.
The product may be further purified by crystallisation from methanol. About 2-8 l, preferably 3-7 l, most preferably 4-5 l of methanol are used per 1 mol of tiotropium bromide (I) and the mixture thus obtained is refluxed until the product dissolves. It is then cooled to 0-1 5° C., preferably 3-7° C. and the product crystallises with stirring. After total crystallisation, the crystals are separated off and finally dried at 30-50° C. under an inert gas, preferably nitrogen.
The product thus obtained may optionally be converted into its monohydrate. To do this, the following method may be used.
In a reaction vessel of suitable size the solvent is mixed with tiotropium bromide. 0.4 to 1.5 kg, preferably 0.6 to 1 kg, most preferably about 0.8 kg of water are used as solvent per mol of tiotropium bromide used. The resulting mixture is heated with stirring, preferably to more than 50° C., most preferably to more than 60° C. The maximum temperature which can be used is determined by the boiling point of the water used as solvent. Preferably the mixture is heated to a range of 80-90° C.
Activated charcoal, dry or moistened with water, is added to this solution. Preferably, 10 to 50 g, most preferably 15 to 35 g, particularly preferably 25 g of activated charcoal are used per mol of tiotropium bromide put in. If desired, the activated charcoal may be suspended in water before being added to the solution containing tiotropium bromide. 70 to 200 g, preferably 100 to 160 g, most preferably about 135 g of water are used per mol of tiotropium bromide put in, in order to suspend the activated charcoal. If the activated charcoal is suspended in water before being added to the solution containing tiotropium bromide, it is advisable to rinse with the same amount of water.
Stirring is continued for between 5 and 60 minutes, preferably between 10 and 30 minutes, most preferably about 15 minutes at constant temperature after the addition of the activated charcoal and the resulting mixture is filtered to eliminate the activated charcoal. The filter is then rinsed with water. This is done using 140 to 400 g, preferably 200 to 320 g, most preferably about 270 g of water per mol of tiotropium bromide used. The filtrate is then slowly cooled, preferably to a temperature of 20-25° C. Cooling is preferably carried out at a cooling rate of 1 to 10° C. per 10 to 30 minutes, preferably 2 to 8° C. per 10 to 30 minutes, most preferably 3 to 5° C. per 10 to 20 minutes, particularly preferably 3 to 5° C. per 20 minutes approximately. If desired, the cooling to 20 to 25° C. may be followed by further cooling to below 20° C., most preferably to 10 to 15° C. After the cooling has taken place, the mixture is stirred for between 20 minutes and 3 hours, preferably between 40 minutes and 2 hours, most preferably about one hour, in order to complete the crystallisation.
Finally, the crystals formed are isolated by filtering or suction filtering of the solvent. If it proves necessary to subject the crystals obtained to another washing step, it is advisable to use water or acetone as washing solvent. 0.1 to 1.0 l, preferably 0.2 to 0.5 l, most preferably about 0.3 l of solvent may be used per mol of tiotropium bromide used in order to wash the tiotropium bromide monohydrate crystals obtained. If desired, the washing step may be repeated.
The product obtained is dried in vacuo or using circulating hot air to achieve a water content of 2.5-4.0%.
The Examples which follow serve to illustrate some methods of synthesis carried out by way of example in order to prepare tiotropium bromide. They are intended to be taken as possible methods provided by way of example, without limiting the invention to their content.
Preparation of the Tropenol Ester (VII)
Ammonia (1.8 kg) is added to 10.9 kg of tropenol hydrochloride in toluene (95 l) at 25° C. The suspension obtained is stirred at constant temperature for about 1 h. The ammonium hydrochloride formed is then filtered off and rinsed with toluene (26 l). At an external temperature of about 50° C. some of the toluene (about 60 l) is distilled off in vacuo. After cooling to about 25° C., 15.8 kg of methyl di-(2-thienyl)glycolate is added and the resulting mixture is heated to 50° C. to dissolve it. Toluene (40 l) is placed in another apparatus and sodium hydride (2.7 kg) is added thereto at about 25° C. The solution previously prepared from tropenol and methyl glycolate is added to this solution within 1 hour at 30° C. After it has all been added the mixture is heated to 75° C. at reduced pressure for about 7 hours with stirring. The methanol formed is distilled off. The mixture remaining is cooled and added to a mixture of water (958 l) and 36% hydrochloric acid (13.2 kg). The aqueous phase is then separated off and washed with methylene chloride (56l). After the addition of some more methylene chloride (198 1) the mixture thus obtained is adjusted to pH=9 with prepared soda solution (9.6 kg of soda in 45 l of water). The methylene chloride phase is separated off and the aqueous phase is stirred with methylene chloride (262 L). The methylene chloride phase is evaporated down to the residue at 65° C. The residue is taken up in toluene (166 l) and heated to 95° C. The toluene solution is cooled to 0° C. The crystals obtained are separated off, washed with toluene (33 l) and dried at about 50° C. for a maximum of 24 hours in a nitrogen current.
Yield: 18.6 kg (83%); melting point: about 160° C. (measured by DSC at a heating rate of 10 K/min);
Preparation of the Scopine Ester (IV)
260 l DMF are placed in a suitable reaction apparatus and heated to 50° C. Then 16.2 kg of tropenol ester (VII) are added and the mixture is stirred until a clear solution is obtained. After cooling to 40° C., hydrogen peroxide-urea complex (10.2 kg), water (13 l) and vanadium-(V)-oxide (0.7 kg) are added successively and in batches and the contents of the apparatus are heated to about 50° C. After 2-3 h stirring at constant temperature the mixture is cooled to about 20° C. The reaction mixture obtained is adjusted to a pH of about 4.0 with hydrochloric acid (36%). Prepared sodium bisulphite solution (2.4 kg in 24 l of water) is added. At an internal temperature of 35° C. the solvent is partly distilled off in vacuo (about 210 l). The mixture is cooled to about 20° C. again and Clarcel (3.2 kg) is added. The resulting mixture is adjusted to a pH of about 2.0 with dilute hydrochloric acid (36%, 0.8 kg in about 440 l of water). The solution obtained is filtered and extracted with methylene chloride (58 l). The methylene chloride phase is discarded. Methylene chloride (130 l) is again added to the aqueous phase and a pH of about 10.0 is obtained using a prepared soda solution (11.0 kg in 51 l of water). The methylene chloride phase is separated off and the aqueous phase is extracted with methylene chloride (136 l). Methylene chloride (about 175 l) is distilled off from the combined methylene chloride phases in a slight vacuum (600-700 mbar) at 40° C. The contents of the apparatus are cooled to 20° C., acetyl chloride (about 0.5 kg) is added and the mixture is stirred for about 40 minutes at 20° C. The reaction solution is transferred into a second apparatus. The pH is adjusted to 2.0 with a prepared hydrochloric acid solution (4.7 kg of hydrochloric acid, 36% strength in 460 l water) at 20° C. The methylene chloride phase is separated off and discarded. The aqueous phase is washed with methylene chloride (39 l). Then methylene chloride (130 l) is added and a pH of 10.0 is obtained with a prepared soda solution (7.8 kg of soda in 38 l water) at 20° C. After 15 minutes' stirring the organic phase is separated off and the aqueous phase is washed twice with methylene chloride (97 l and 65 l). The methylene chloride phases are combined and some of the methylene chloride (90 l) is distilled off in a slight vacuum at a temperature of 30-40° C. Then dimethylformamide (114 kg) is added and the remaining methylene chloride is distilled off in vacuo at 40° C. The contents of the apparatus are cooled to 20° C.
Preparation of the Tiotropium Bromide (I)
Methyl bromide (5.1 kg) is added to the scopine ester solution obtained according to the procedure described above at 20° C. The contents of the apparatus are stirred at 30° C. for about 2.5 days. At 50° C., 70 l of DMF are distilled off in vacuo. The solution is transferred into a smaller apparatus. It is rinsed with DMF (10 l). More DMF is distilled off at 50° C. in vacuo until a total of about 100 l of distillate is obtained. It is cooled to 15° C. and stirred for another 2 hours at this temperature. The product is isolated using suction dryers, then washed with cold DMF (10 l) at 15° C. and cold acetone (25 l) at 15° C. It is dried at a maximum temperature of 50° C. for not more than 36 hours in a nitrogen current.
Yield: 13.2 kg (88%); melting point: 200-230° C. (depending on the purity of the crude product);
The crude product thus obtained (10.3 kg) is added to methanol (66 l). The mixture is refluxed to dissolve it. The solution is cooled to 7° C. and stirred for 1.5 h at this temperature. The product is isolated using suction dryers, washed with cold methanol (11 l) at 7° C. and dried for max. 36 h at about 50° C. in a nitrogen current.
Yield: 9.9 kg (96%); melting point: 228° C. (determined by DSC at a heating rate of 10 K/min).
If desired, the product thus obtained can be converted into the crystalline monohydrate of tiotropium bromide. This can be done as follows.
15.0 kg of tiotropium bromide are added to 25.7 kg of water in a suitable reaction vessel. The mixture is heated to 80-90° C. and stirred at constant temperature until a clear solution is formed. Activated charcoal (0.8 kg), moistened with water, is suspended in 4.4 kg of water, this mixture is added to the solution containing tiotropium bromide and rinsed with 4.3 kg of water. The mixture thus obtained is stirred for at least 15 min at 80-90° C. and then filtered through a heated filter into an apparatus which has been preheated to an outer temperature of 70° C. The filter is rinsed with 8.6 kg of water. The contents of the apparatus are cooled to a temperature of 20-25° C. at a rate of 3-5° C. per 20 minutes. The apparatus is further cooled to 10-15° C. using cold water and the crystallisation is completed by stirring for at least one hour. The crystals are isolated using a suction drier, the isolated crystal slurry is washed with 9 l of cold water (10-15° C.) and cold acetone (10-15° C.). The crystals obtained are dried at about 25° C. over about 2 hours in a nitrogen current.
Yield: 13.4 kg of tiotropium bromide monohydrate (86% of theory)
Melting point: 230° C. (determined by DSC at a heating rate of 10 K/min).
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The invention relates to a new process for preparing a scopine ester useful as an intermediate in preparing (1α,2β,4β,5α,7β)-7-[(hydroxydi-2-thienylacetyl)oxy]-9,9-dimethyl-3-oxa-9-azoniatricyclo[3.3.1.0 2,4 ] nonane-bromide.
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FIELD OF THE INVENTION
This invention relates to a process for dimerizing esters of acrylic acid and methacrylic acid to esters of, respectively, hexenedioic acid and dimethylhexenedioic acid.
BACKGROUND OF THE INVENTION
There are several references in the literature to the use of palladium compounds for the dimerization of acrylate esters. For example, U.S. Pat. No. 4,451,665, issued May 29, 1984, disclosed the use of tetrakis(hydrocarbylnitrile)palladium(II)tetrafluoroborate as a catalyst for the dimerization of acrylate and methacrylate esters. Oehne and Pracejus, in Tetrahydron Letters (1979, pp 343-348) discloses the use of a dimerization catalyst prepared from bis(benzonitrile)palladium(II)dichloride and silver tetrafluoroborate. Alderson et al, Journal of the American Chemical Society (1965) 87 pp 5638-5645 discloses the use of rhodium chloride in an uncomplexed form to dimerize methyl acrylate.
Dialkyl hexenedioates are readily convertible to adipic acid (hexanedioic acid) by hydrogenation and subsequence hydrolysis. Adipic acid in turn is used in large volume in the production of the condensation polymers, particularly Nylon 66. Therefore, even a small improvement in any method for making dialkyl hexenedioates can be of major commercial significance.
A system that will catalyze the dimerization of methacrylate esters to "linear" diesters, that is, 2,5-dimethylhexenedioates, which are the products having the longest possible chain with terminal alkoxycarbonyl groups, is also a desirable objective. 2,5-Dimethylhexanedioic acid, available from dialkyl 2,5-dimethylhexenedioates, is also useful in making condensation polymers such as polyamids and polyesters.
SUMMARY OF THE INVENTION
The instant invention relates to a process for dimerizing a lower alkyl acrylate or a lower alkyl methacrylate to the corresponding dialkyl hexenedioates and dialkyl 2,5-dimethylhexenedioates by contact with a catalyst prepared by reacting chloroobis(ethylene)rhodium(I)dimer and silver tetrafluoroborate. The instant catalyst provides an alternative to known palladium catalysts and provides a dimerization process with high selectivity to "linear" that is, unbranched, dimers at low dimerization temperatures with high conversions and yields.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention resides in the process which comprises contacting a lower alkyl acrylate or lower alkyl methacrylate, with lower alkyl being alkyl of 1 to 8 carbon atoms with a catalyst prepared by reacting chlorobis(ethylene)rhodium(I)dimer with silver tetrafluoroborate, optionally in the presence of a free radical inhibitor for acrylate or methacrylate polymerization inhibition, which process is carried out at a temperature between about 0° C. to about 150° C., more preferably between about 20° C. and about 75° C., to produce one or more dialkyl hexenedioates (from the alkyl acrylate) or a dialkyl 2,5-dimethylhexenedioates (from the alkyl methacrylate).
The size of the alkyl group in the alkyl acrylate or alkyl methacrylate is not critical. However, lower alkyl, of one to eight carbon atoms, acrylates and methacrylates are preferred because of their availability, and the methyl and ethyl esters are especially preferred because of the ease of isolation of the resultant reaction products. Particularly preferred are the methyl acrylates and methyl methacrylates. The alkyl group can be substituted with any group that does not interfere with the desired reaction.
The catalyst used in the instant dimerization process is typically prepared by reacting chlorobis(ethylene)rhodium(I)dimer, ((C 2 H 2 ) 2 RhCl) 2 , and silver tetrafluoroborate, AgBF 4 , in the presence of an olefin to retard decomposition to the metal. The catalyst may be prepared in situ in the presence of the methacrylate or acrylate to be dimerized, or more preferably the catalyst may be prepared utilizing another olefin, and the total reaction mixture is then used then to catalyze the dimerization reaction. One advantage of the instant catalyst is that it is particularly suited for the selective dimerization of acrylates and methacrylates even in the presence of other olefins. Thus, the use of an olefins such as, hexene or octene in the catalyst preparation technique does not effect the subsequent dimerization of the acrylate or the methacrylate to give a pure hexenedioate product. Both the chlorobis(ethylene)rhodium(I)dimer and the silver tetrafluoroborate are readily available commercially. Typically, about one mole of tetrafluoroborate is used with half a mole of the dimer although differing amounts, particularly, greater amounts can be utilized.
The amount of rhodium catalyst charged depends largely on the amount of alkyl acrylate or methacrylate used, and the ratio of moles of alkyl acrylate or alkyl methacrylate to gram atoms of rhodium can vary widely. Usually, to permit efficient use of the catalyst, the ratio is at least about 10:1 and can be as high as about 10000:1, more preferably between about 20:1 to about 1000:1. It is also desirable in the reaction mixture to add a sufficient amount of a free radical inhibitor to prevent polymerization of the acrylates and methacrylates. These inhibitors are well known in the art and include for example, hydroquinone, 2,4,6-tri(tertiarybutyl)phenol, 2,6-di(isobutyl)-4-tertiary butyl phenol, and the like. Typically, amounts of inhibitor utilized comprise less than about 1 mole percent of the initial acrylate or methacrylate charge.
The instant process can be conducted over a rather broad range of temperature, for example, from about 0° C. to about 150° C., although 100° C. is a preferred maximum. The temperature chosen will depend on such variables as the particular acrylate or methacrylate to be dimerized, the catalyst concentration, and the time over which it is convenient or desired to operate the process. For example, when methacrylate is dimerized a convenient temperature of operation ranges from about 35° C. to about 75° C. The times of reaction can very widely, from a few minutes to several days. Preferably, the reaction is carried out in about 15 minutes to about 72 hours.
The process of the instant invention is illustrated by the following example which is provided for illustration only and is not to be construed as limiting the invention.
EXAMPLE I
The following example describes the preparation of the catalyst and its use in the dimerization of methyl acrylate.
To an 80 ml autoclave were added 36.4 ml of 1-octene, 1.90 g (5 mmole) of chlorobis(ethylene)rhodium(I)dimer obtained from steam Chemicals, 1.9 g (10 mmole) of silver tetrafluoroborate and 5 ml of cyclohexane to be used as a marker in subsequent product analysis. The reactor was sealed and stirred at ambient temperature in order to allow the catalyst reaction to take place. Then, 15 ml of methacrylate containing 0.02%w hydroquinone were added to the autoclave. The autoclave was heated to about 48° C. for about 1.3 hours and then cooled and a sample removed. The autoclave was reheated to 68° F. for about 1.3 hours, then cooled, sampled, and reheated to 78° C. for about 14.5 hours. Results for these experiments are shown in the table following. The quantitative data for the dimethyl hexenedioate was obtained by assuming the same GC factor as was established for methyl acrylate. The identity of the dimethyl hexenedioate was confirmed by GC/MS and NMR.
COMPARATIVE EXAMPLE A
In this example, only bischloro(ethylene)rhodium(I)dimer was utilized as the catalyst and no silver tetrafluoroborate was used. In this case the reaction temperature had to be raised to over 100° C. in order to obtain significant conversions. Results are shown in the table. Without the use of the silver tetrafluoroborate, significant quantities of the "linear" hexenedioate are not obtained.
______________________________________ Turnovers (hr.sup.-1)Catalyst Deg C Hrs % Conv.sup.a % Yield.sup.b MeAcr..sup.c Ester.sup.d______________________________________I 48 1.3 37 48 4.7 2.2 68 1.3 73 64 4.7 3.7 78 14.5 100 60 0.3 0.14A 101 1.0 4 41 0.7 0.3 143 0.8 16 27 2.5 0.6 152 16.0 33 21 0.2 0.03______________________________________ .sup.a Percent methyl acrylate converted. .sup.b Moles ester product formed per 100 moles methyl acrylate converted where ester product = dimethylhexenedioate for I (corr. for stoichiometry = methylundecenoate for A. .sup.c Incremental moles methyl acrylate converted/mole catalyst/hour. .sup.d Incremental moles ester product formed/mole catalyst/hour. where ester product = dimethylhexenedioate for I. = methyl undecenoate for A.
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A process is disclosed for dimerizing lower alkyl acrylates or lower alkyl methacrylates utilizing a bis(ethylene) rhodium tetrafluoroborate catalyst.
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RELATED APPLICATION
This application is a continuation of application Ser. No. 939,984 filed Dec. 10, 1986, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a frame retractable blind or screen which can be gathered up. One general type of such a frame has an upper head-rail consisting of a hollow profile, and a bottom rail which can be raised and lowered, and which forms the bottom of the frame, and which can be actuated for the purposes of raising and lowering the blind. Lateral profiles, though which cords run, are attached to the head-rail by means of corner members.
It is known to provide, for example, slatted Venetian blinds, particularly for fixing to the insides of inclined skylights, having metal profiles fixed laterally to their top horizontal head-rail by means of corner members. Each of these lateral, obliquely extending profiles has a cavity in which in each case a carriage is guided, these carriages supporting the bottom strip, cf German Utility Model 8110574.
Widely varying methods are known for actuating known Venetian blinds and for providing stability in the case of special Venetian blinds such as for roof windows, skylights, etc. Each of these forms of actuation requires different means of guiding the cords used. The conventional frames for retractable blinds are restricted to one, or at most two, forms of actuation so that alternative forms of actuation are not possible or require different structural parts.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a frame for retractable blinds of the type initially mentioned which permits the most varied forms of actuation and fixing and a wide variety of guide arrangements for the cords used for the purpose.
According to the invention there is provided a frame for a retractable screen which can be gathered together. The frame comprises an upper head-rail consisting of a hollow profile, a bottom rail which can be raised and lowered and which forms the bottom of the frame, lateral profiles, corner members connecting the head-rail to the lateral profiles, longitudinal channels in said longitudinal profiles, draw cords passing through the lateral channels, a plurality of cord passages in the corner members, all of which are connected to one another via a common space and a sliding surface associated with each cord passage to deflect the draw cords, as they pass from the head-rail to the associated lateral profile.
A design of this type permits a very wide variety of guideways for the draw cords, which term is used to include actuating, tensioning and/or guiding cords, so that a high degree of variability of actuation of the retractable screen such as a Venetian blind is achieved, in particular, by means of the assembly. This means not only that the form of actuation can be changed after installation, but also that the widest variety of versions of Venetian blinds or roller blinds can be offered and sold without requiring different individual parts. Passages are understood to mean the paths to be followed by the cords.
Thus, draw cords can be brought out at the top corner member or at a bottom foot member or at both in order to be manipulated. They can however also be actuated by an operating slide guided in the lateral profile, or the bottom rail can be moved directly by hand and merely guided by the tensioning cords, it being possible for these tensioning cords to be fixed or movable. Tensioning and/or guiding cords can also be used in addition to actuating cords, specifically in the case of obliquely or horizontally positioned blinds. Each of these forms of actuation requires very different guidings of the cords, all of which can be implemented by means of the invention.
It is particularly advantageous in this context if a plurality of passages extend from the common space to the head-rail and to the lateral profile. It is also proposed for this purpose that a plurality of passages leading from the common space to the front outer face should be provided.
It is advantageous if at least one passage terminates in the interior of the lateral profile. In this case the lateral profile can have two or more longitudinal channels, and one passage of each of the corner member can terminate in each of these channels. It is also proposed that upper passages, opposite to each other when viewed in the lengthwise direction of the head-rail, should be provided in the corner member, one of these passages in each case terminating in the head-rail. It is particularly advantageous if each of the opposing passages forms a plurality of exit directions and has corresponding sliding surfaces. In this case a passage can lead off from the upper passages and terminate at the front of the corner.
It is particularly advantageous if the passages are formed by a separate moulding which is fixed in the interior of the corner member. A moulding of this type, lying in the corner member, may be produced from particularly hard-wearing material, and especially from plastic which is resistant to cord friction, so that the degree of wear is low. In this context it is also proposed that two projections should be formed on the top of the moulding, forming between them a U-shaped passage, particularly a passage to the front. These upper projections ensure that the various cords are securely guided and do not become tangled, and these projections also form stops for the corner member.
Simple and secure fixing of the moulding is achieved, because the moulding can be pushed into the lateral profile from above by means of a projection.
Simple assembly and a large number of variations are achieved if a foot member is attached to the bottom end of each of the lateral profiles, this foot member having a plurality of passages for the cords. In this case at least one passage can terminate in the interior of the lateral profile. It is also proposed in this context that the lateral profile should have two longitudinal channels and that one passage of each foot member should terminate in each of these longitudinal channels. Moreover, a passage can terminate at the front of the foot member. A passage can also terminate at the side facing the side-piece of the window. In a further alternative it is proposed that a passage terminates horizontally in the side facing the opposite foot member.
In an advantageous embodiment it is proposed that, where the lateral profiles have two longitudinal channels, at least the rear one of these is open to the back over its entire length, and that a carriage be guided in the rear longitudinal channel, the bottom rail being fixed to this carriage. In this case the carriage can be fixed to the bottom rail via a tubular hollow bolt in which a draw-cord can be inserted, this draw-cord passing transversely through the bottom rail or being attached thereto. This results in a particularly simple and easily installed guiding of the cords. In this case the carriage may have a horizontal aperture into which the hollow bolt can be pushed, and a passage provided for the cords on or in the carriage is connected to the aperture.
In order that the invention will more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1a is a perspective view of one embodiment of slatted Venetian blind, according to the invention partly broken away, and with the slats removed;
FIG. 1b is a horizontal section to a reduced scale through the Venetian blind of FIG. 1;
FIG. 2a, 2b and 2c are a front view, a side view and a plan view of the left corner member;
FIG. 3a is an bottom view of the moulding which is fixed within the corner member;
FIG. 3b is a lateral view of the moulding;
FIG. 3c is a section along A--A in FIG. 3d;
FIG. 3d is a plan view of the moulding;
FIG. 4a is a view from below of the left foot member of the Venetian blind;
FIG. 4b and 4c are a side view and a front view of the foot members;
FIG. 4d is a section along A--A of FIG. 4e;
FIG. 4e is a plan view of the foot member;
FIG. 5 is a perspective view of the carriage of the frame;
FIG. 5a is a side view of the carriage;
FIG. 6 is an enlarged section through a lateral profile of the blind;
FIG. 7a is a lateral view of an end cap which can be pushed on either end of the bottom rail; and
FIG. 7b is a section along A--A on FIG. 7a.
DETAILED DESCRIPTION OF THE INVENTION
A variety of retractable screens, such as a slatted Venetian blind, a folding Venetian blind, a folding curtain or a roller blind may be used with the frame disclosed herein. The invention is described below with reference to a slatted Venetian blind which, relative to other retractable screens, merely has an additional tilting device for the slats. The slatted Venetian blind shown with the frame in FIG. 1a is preferably fixed on the inside of an oblique roof window, particularly such a window which can also be tilted. The frame has a horizontal head-rail 1 which is U-shaped in cross-section, and from which ladder-cords 2 hang down, these ladder-cords being indicated in broken lines in FIG. 1a and holding the individual slats, which are not shown, at the necessary distance apart. A longitudinal tilt rod (not shown) is mounted in a conventional manner in the head-rail 1 and can be rotated by means of a tilt bar 3 in order to turn the slats by means of the ladder-cords 2.
Projections 5 formed in corner members 4 are pushed into the ends of the head-rail 1 (cf FIGS. 2a and 2c). These corner members 4 provide a means of connection between the head-rail 1 and lateral profiles 6. The lateral profiles 6 are fixed to the lower parts of the generally square-shaped corner members 4 and extend downwards along both sides of the window, so that in the case of a sloping roof window, the profiles 6 are arranged parallel to the sloping window side-pieces.
The two lateral profiles 6 each form a front and rear channel 6a, 6b, through which the Venetian blind draw-cords can run (FIG. 6). These channels are open to the front and rear respectively over their entire length. Each corner member 4 has a hole 7 passing through the corner part from bottom to top, this hole being oblique and hence not parallel to the profile 6, and it being possible to push a wood screw into this hole in order to fix the corner member 4 to the top frame of the window.
A moulding 8 fits snugly in the interior of the hollow plastic corner member 4, this moulding 8 consisting either of a metallic material or of a plastic which has high wear resistance to the friction of the draw-cords and forming the passages for the draw-cords through the corner member 4. The moulding 8 has a projection 9 (FIGS. 3a-3c) on its lower side, this projection resting in the rear longitudinal channel 6b of the profile 6. In order to form the passages, the moulding 8 has two downward-extending channels 10, 11 (FIGS. 3c, 3d) which terminate in the longitudinal channels 6a, 6b of the profile 6. The channels 10, 11 extend from a central region of the moulding 8, and three additional passages 12, 13, 14 also start from this region, of which the passage 12 extends horizontally to the interior of the head-rail 1 and the passage 13 extends horizontally outwards in the opposite direction. A passage 14 also begins in the central region of the moulding 8, extends to the front of the corner member 4 and terminates through an aperture 15 in the corner member 4 (FIG. 2a). The passages 10-14 are thus all connected to each other in the interior of the moulding 8 and hence also in the interior of the corner members 4, and extend from this central region with two passages 10, 11 downwards into the channels of the profile 6, to both sides (passages 12, 13) and forwards (passage 14). Since a draw-cord passing through one of the passages into the interior of the moulding 8 can emerge again through one of the other passages, and since these passages are at right angles to each other, curved sliding surfaces 16 are arranged as the transition between the passages in order to guide the draw-cord in question. Because of the many types of connection between the passages, the moulding has a total of six sliding surfaces 16a.f. Because of the high slip and wear resistance of the moulding, the draw-cords can be drawn over these sliding surfaces without significant friction.
The moulding 8 has projections 8a, 8b moulded onto its top and extending upwards, the passage 14 running between these projections which, with their tops, form stops for the surface of the corner member 4. These projections 8a, 8b form the slip surfaces 16a, 16f with their longitudinal edges, which run approximately vertically.
At the bottom of each of the profiles 6 a foot member 17, having projections 18, is pushed into the longitudinal channels 6a, 6b. In a similar manner to the corner part 4, the foot part 17 has a plurality of passages for the draw-cords (FIGS. 4a-4e). The passages 20, 21 extending parallel to the profiles 6 lead to the interior of the foot members 17, from which passages 22, 23 extend to the side or forward. In this case, the passage 22 leads towards the opposite foot member. It is important that, in the same way as in the case of the moulding 8, all passages are connected to one another via the internal cavity of the foot member 17, so that a draw-cord entering the interior of the foot part through one of the passages can emerge through one of the other passages. An additional frame profile (not shown) can, if required, be provided between the foot parts 17 at the level of the foot parts. A further passage 19 can also terminate at the side facing the side-piece of the window, in a region covered by the lateral profile.
A carriage 24 lies slidingly in the rear longitudinal channel 6b of the profile 6, it being possible for upward or downward extending draw-cords which run in the rear channel 6b to be attached to this carriage 24. A hollow bolt 25 is horizontally attached to the carriage 24 and passes axially into the bottom rail 26 of the Venetian blind. For this purpose the end parts 27 pushed onto both ends of the bottom rail 26 have apertures 27a (FIGS. 7a-7b). Draw-cords can run through these hollow bolts 25, and rest in the interior of the bottom rail 26 and, after emerging on the outside from the hollow bolts 25, are deflected via slip surfaces 28 of the carriage 24 into the rear channel 6b of the profile 6. The continuous draw-cords can be fixed under tension by means of tension springs 29 which may be located in the bottom rail 26.
A operating slide 30 is slidingly mounted in the front longitudinal channel 6a of the left profile 6, this slide 30 being manually pushed downwards in order to move the bottom rail 26 upwards and being pushed upwards in order to lower the bottom rail. The slide 30 has a top aperture 30a, in which two cords I, IV extending downwardly from above are clamped, and a bottom aperture 30b in which two cords II, III extending upwardly from below through the profile 6 are clamped. The slide 30 can be clamped to the profile 6 by means of a lock (rotating knob) 31, so that the bottom rail can be immovably locked. In the clamped state, the cords I-IV can be released, i.e. can rest movably in the apertures 30a, 30b of the slide 30, so that the bottom strip 26 can be moved up and down by pulling alternately on these cords.
The cords I-IV can be threaded through the parts of the frame in a variety of ways. One of the methods of fixing and laying the cords is described below, reference being made to FIGS. 1a and 1b. To the right-hand carriage 24 is fixed, in particular, the end of the cord I which rests in the rear channel 6b of the profile 6 and is guided upwards through this channel. The right-hand moulding 8 deflects the cord I into the head-rail 1, and the cord I runs through the interior of the head-rail 1 to the left-hand moulding 8, which guides the cord I into the front channel 6a of the left-hand profile 6. From the channel 6a the cord I passes to the slide 30, to which it is attached, or through which it can be pulled in the clamped position of the slide. In the same way a cord IV is attached to the left-hand carriage 24, particularly at the top, this cord IV passing through the rear channel 6b of the left-hand profile, through the left-hand moulding 8 and through the front channel 6a to the handle 30. The bottom rail 26 can be pulled up via the carriages 24 by means of the two cords I, IV if the handle is pushed downwards or if the cords are pulled forwards out of the slide when the latter is locked.
On the bottom rail 26, two further cords II, III, are attached, in particular, to the carriage 24 or are attached to the springs 29. The right-hand cord II is guided downwards through the rear channel 6b of the right-hand profile 6 to the right-hand foot member 17, deflected by this into the channel 6c of the profile, guided upwards through the channel 6c to the right-hand moulding 8, from there through the head-rail to the left-hand moulding 8 and into the channel 6c of the left-hand profile 6 to the left-hand foot member 17 which deflects the cord II into the front channel 6a and upwards to the slide 30. In the same manner, a cord III is attached to the left-hand spring 29 or carriage 24 and enters the rear channel 6b of the left-hand profile 6 via the left-hand carriage 24, this channel 6b guiding it to the left-hand foot member 17 which deflects the cord III into the front channel 6a and upwards towards the slide 30. Pulling on the cords II, III by moving the slide 30 upwards or by directly pulling these cords out of the slide 30 when it is locked results in the lowering of the bottom rail 26.
The mouldings 8, foot members 17 and profiles 6 permit numerous other ways of guiding and actuating the Venetian blind and cords. For example, cords can emerge, for the purposes of actuation, from one of the corner members 4 or foot members 17 and can also pass transversely through the bottom rail 26.
It is particularly important that the carriages 24 are slidingly guided in the rear channels 6b and the cords starting from there extend in the first region in these channels 6b, and that the slide 30 is slidingly guided in one of the two front channels 6a and the cords starting from the said handle slide in these channels 6a in the first region.
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A frame for a retractable blind which can be gathered together, said frame comprises an upper head-rail consisting of a hollow profile, a bottom rail which can be raised and lowered and which forms the bottom of the blind, lateral profiles, corner members connecting the head-rail to the lateral profiles, longitudinal channels in said lateral profiles, draw cords passing through the lateral channels, a plurality of cord passages in said corner parts, all of which are connected to one another via a common space and a sliding surface associated with each cord passage to deflect the draw cords, as they pass from the head-rail to the associated lateral profile.
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FIELD OF THE INVENTION
The present invention relates to practice or training weapons and, more particularly, to a practice grenade which forcefully disperses a colored liquid marking medium by the action of a spring driven piston and which includes an inertial delay mechanism.
BACKGROUND OF THE INVENTION
In the past, war games in military training were often judged or scored by umpires based on troop strength and tactical position and statistical analysis thereof. More currently, special training weapons are often employed in such training to sharpen combat skills and to provide a mechanism for objectively scoring proficiency in such skills. For example, rifles having the look and feel of currently employed combat rifles are fitted with laser emitters, and combatants wear laser receivers which record a "kill" when a laser signal is received. Such an arrangement develops the aiming skill of the shooter while providing an objective indication of a "casualty".
In recent years, a combat type sport has developed in which the principal equipment or weapon is a gun which shoots paintballs. The propellant in the gun is compressed air or carbon dioxide cartridges. The paintballs are substantially spherical capsules, often formed of pharmaceutical capsule type gelatin, filled with a washable, pigmented liquid, resembling latex type paint in some respects. Currently, the principal participants are civilians grouped in teams who execute strategies and tactics, according to established rules, in competition with an opposing team. If a player is shot by a paintball, the player is considered a casualty and is unable to further assist his team. Because of the bright colors of the paints used and the difficulty of removing the results of a hit in the field, scoring of hits or casualties can be accomplished objectively.
In the area of anti-personnel weapons, such as grenades, mines, and the like, it has generally been difficult to devise safe simulation devices with which casualties can be objectively scored. Generally, devices which emit a loud report and/or smoke are employed, and scoring is done on a basis of survival statistics within a given radius of the weapon simulated.
At least one toy grenade is known which disperses a dye liquid upon detonation. The grenade body is filled with the dye liquid and compressed air and has a valve controlling flow of the liquid to dispersion orifices. The valve is controlled by a trigger mechanism which extends from the lower end of the grenade when armed. The grenade body is weighted so that, at least theoretically, when the grenade is thrown, it lands on the lower end and actuates the trigger. One inherent problem with this grenade is that the liquid releasing valve is at the top of the liquid chamber such that if the grenade lands as intended, when the valve opens, the compressed air escapes first and is unavailable for propelling a major portion of the liquid. And unless the grenade lands lower side down, actuation of the trigger mechanism is not assured.
SUMMARY OF THE INVENTION
The present invention provides a liquid dispersing training grenade in which the propelling force is provided by a compressed spring which drives a piston to forcefully rupture a pellet containing a pigmented liquid or paint. Passages extend in universal directions from an end of a central bore in which the paint pellet is located. The piston is initially held by a release lever releasably pivoted on the grenade body. A delay mechanism is provided which temporarily prevents movement of the piston when the release lever is disconnected from the grenade body and separated.
The delay mechansim includes a plurality of delay levers pivoted within the grenade body and engaging the piston. The ends of the delay levers have delay wheels mounted thereon which engage tracks within the grenade body. The delay wheels are configured to have substantial angular inertia which must be overcome to initiate rotation thereof. The delay levers have fulcrum pivots positioned to multiply the inertial resistance force of the delay wheels back to the piston. The delay levers are also configured such that they must be pivoted to a certain angle before the piston can slide by them. The delay wheels are preferably pinion gears meshed with rack gears within the grenade body.
OBJECTS OF THE INVENTION
The principal objects of the present invention are: to provide an improved training grenade type device; to provide such a grenade which is non-pyrotechnic and non-lethal; to provide such a grenade which gives a clear indication of "hits" for military type training; to provide such a grenade which forcefully disperses a charge of a pigmented colorant or paint upon "detonation"; to provide such a grenade wherein the colorant is inert, non-poluting, and washable; to provide such a grenade wherein the colorant is contained within a rupturable and replaceable pellet; to provide such a grenade wherein the mechanism for releasing the colorant includes a piston driven by a compressed spring; to provide such a grenade including a pinned release lever which safely maintains the spring in a compressed state and which is used as a lever to facilitate the final stage of compressing the spring; to provide such a grenade wherein the release lever reliably releases the piston to crush the colorant pellet; to provide such a grenade including a delay mechanism to provide a short delay between separation of the release lever and actual release of the piston to allow the grenade to be thrown before dispersion of the colorant occurs; to provide such a grenade wherein the delay mechanism exploits the startup angular momentum of friction wheels or gears in cooperation with lever arms to provide the delay; to provide such a grenade which can be conveniently disassembled, washed, and reloaded for reuse; and to provide such a training paint grenade which is economical to manufacture, reliable in operation, and which is particularly well adapted for its intended purpose.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a paint dispersing training grenade embodying the present invention.
FIG. 2 is an enlarged cross sectional view illustrating a paint pellet, a spring driven pellet rupturing piston, and an inertial delay mechanism of the grenade.
FIG. 3 is a fragmentary view similar to FIG. 2 and shows the piston in an extended position and the pellet collapsed.
FIG. 4 is a conical sectional plan view taken at a reduced scale on a surface described by lines 4--4 of FIG. 2 and illustrates a pattern of paint dispersion passages of the grenade.
FIG. 5 is an enlarged fragmentary sectional view of a modified delay component of the grenade incorporating a rack and pinion.
FIG. 6 is an enlarged fragmentary cross sectional view similar to FIG. 2 and illustrates further details of the modified delay mechanism of the grenade of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Referring to the drawings in more detail:
The reference numeral 1 generally designates a paint dispersing training grenade according to the present invention. The grenade 1 generally includes a grenade body 2 having a central cavity or bore 3 with a paint pellet 4 positioned therein, a pellet crushing piston 5 positioned in the bore 3 and urged toward the pellet 4 by a cOmpressed spring 6, a release lever 7 attached to the grenade body 2 and engaging an upper end of the piston 5 to prevent it from moving, and a delay mechanism 8 engaged between the grenade body 2 and the piston 5. Upon separation of the release lever 7 from the grenade body 2 and piston 5, the spring 6 urges the piston 5 against the delay mechanism 8 which, after a short delay, pivots out of the way of the piston 5. Thereafter, the piston 5 is driven against the pellet 4, rupturing same, and propelling a colorant or paint 9 therein out of the grenade body 2 through dispersion passages 10 communicating between the bore 3 and an external surface 11 of the grenade 1.
The grenade body 2 may be formed in any practical shape such as spherical, cylindrical, stepped cylindrical, or ovoid, i. e. egg-shaped, as is illustrated. Preferably, the grenade body 2 is shaped and balanced similar to the actual weapon it is intended to simulate, especially for military training purposes. The grenade body 2 is preferably formed of a high strength and durability plastic material. It may be formed in halves (not shown), for more convenient manufacture and access to the interior for cleaning and repair, and assembled by suitable fasteners (not shown).
The bore 3 extends centrally through the grenade body 2. A lower end of the bore 3 has internal threads 14 to receive a plug 15 against which the pellet 4 will be crushed. The plug 15 has dispersion passages 16 formed therethrough. A slot 17 may be formed in a lower surface of the plug 15 to receive a screwdriver or coin to facilitate installation and removal of the plug 15. The removable plug 15 is provided for access to the bore 3 to facilitate re-arming or resetting the grenade 1 and for cleanup thereof and replacement of pellet 4 after use. Immediately above the threads 14, a circumferential paint distribution channel 20 is formed which communicates with the paint dispersion passages 10.
At the opposite end of the bore 3 from the plug 15, an annular shoulder is formed by a ring 22 attached to the grenade body 2. The spring 6 bears against the ring 22 when it is compressed. The spring 6 is a helical compression spring and resiliently engages the piston 5 to urge it against the paint pellet 4. The piston 5 has a piston shaft 24 extending thereabove which terminates in a disk shaped abutment 25 which is engaged by the release lever 7 to resist the force of the spring 6 until simulated detonation of the grenade 1 is desired. The abutment 25 has a smaller diameter than the inner diameters of either the ring 22 or the spring 6 in order to pass easily therethrough.
The release lever 7 is curved to roughly conform to the external surface 11 of the grenade body 2 and has a forked upper end 27 to straddle the piston shaft 24. The lever 7 is perferably formed of metal to avoid being bent. The release lever 7 must be connected to the grenade body 2 in at least two places to prevent it from being pivoted by the force of the spring 6. A release lever pivot pin 28 is mounted in a pair of ears 29. The release lever 7 is provided with a pivot hook 30 which forms a partial pivot for the release lever. Since the hook 30 is open toward the upper end 27 of the release lever 7, pivoting of the release lever through a small angle causes the lever 7 to be released from the grenade assembly to prevent the upper end 27 from blocking movement of the piston abutment 25. A second connection point for the release lever 7 is provided by cooperating tabs 31 and 32 positioned respectively on the grenade body 2 and the release lever 7 and an arming pin 33 which preferably includes a ring 34 to facilitate gripping. The illustrated grenade 1 includes a lanyard 36, which may be elastic, attaching the release lever 7 to the grenade body 2 to prevent loss of the release lever.
The illustrated pellet or colorant container 4 is substantially cylindrical with hemispherical ends and is sized to fit within the bore 3 with a small clearance between it and the surface of the bore 3. The pellet 4 may be formed of any material which is durable in storage and which will not be softened by interaction with the colorant or paint 9 but which will easily rupture under the pressure of the piston 5. The material forming the pellet 4 may be pharmaceutical capsule type gelatin, a suitable plastic, or the like. The colorant 9 is preferably a pigmented, low viscosity liquid which will not react with the pellet material. Low viscosity is desirable to facilitate propulsion of the colorant 9 through the dispersion passages 10. The colorant or paint 9 is preferably pigmented densely enough for good visibility without appreciably increasing the viscosity thereof. Bright colors, such as yellow, orange, white, and the like, are preferred for high visibility. The paint 9 is formulated to be washable to avoid permanent staining of uniforms and components of the grenade 1, to be nonpolluting, and to be noninjurious, nontoxic, and nonirritating. Even so, it is recommended that eye protection, such as goggles, be worn during use of the grenade 1 to avoid possible eye injury from the colorant 9 travelling at high velocities upon detonation of the grenade. An alternative to the illustrated pellet 4 and colorant 9 is a pellet employing two compartments (not shown) for containing two liquids, one containing a pigment or dye, which are mixed when the pellet is crushed to form an effervescent liquid to provide an additional propulsive force to the colorant from the grenade 1.
The delay mechanism 8 may be any type of mechanism which provides a short delay between release of the release lever 7 and rupture of the pellet 4, to allow time for the grenade 1 to be thrown before bursting of the pellet occurs. The illustrated delay mechanism 8 includes a pair of delay levers 39 pivotally mounted in sector shaped cavities 40 formed within the grenade body 2 by delay pivots 41 and positioned for engagement by the piston 5 to block same. Outer ends of the levers 39 have delay wheels 42 rotatably mounted thereon which rollingly engage a surface 43 within the cavities 40. In FIGS. 2 and 3, the wheels 42 frictionally engage the surface 43 while FIGS. 5 and 6 show one of the wheels 42 as a pinion 45 meshed with a curved rack gear 46 formed or positioned on the surface 43 of the cavity 40. Outer ends 47 of the delay levers 39 are angled off or ramp shaped such that the delay levers must be pivoted to a selected angle before the piston 5 is cleared to move by the delay levers (see FIG. 3). The delay levers 39 are urged toward their blocking positions by delay lever orienting torsion springs 48 (FIG. 6) to avoid movement of the delay mechanisms 8 to their nonblocking positions by gravity if the grenade 1 has been in an inverted orientation prior to use.
The illustrated delay mechanism 8 exploits the angular momentum of the wheels 42 to provide the delay. The rotational startup inertia of the wheels 42 must be overcome by the force of the spring 6 in order to pivot the delay levers 39 out of the way of the piston 5. The force of resistance to pivoting of the delay levers 39 provided by the delay wheels 42 is multiplied by the ratio of the moment arms of the portions of the delay levers on opposite sides of the pivots 41. Referring to FIG. 6, a wheel lever arm 50 extending between the pivot 41 and the point of contact of the wheel 42 with the surface 43 is considerably longer than a piston lever arm 51 extending between the pivot 41 and the point of contact of the piston 5 with the delay lever 39. The spring constant of the delay lever orienting spring 48 contributes a negligible amount of resistance to pivoting of the delay lever 39 because its moment arm is comparable to that of the piston lever arm 51. Although the resistance force developed by the rotational startup inertia of the wheels 42 is small compared to the force of the spring 6, overcoming the resistance force to pivot the delay levers 39 to a release angle requires a finite amount of time.
A sufficient number of passages 10 and 16 are formed in the grenade 1 and plug 15 to provide for dispersion of the colorant 9 in universal directions from the grenade 1. As illustrated in FIGS. 1, 2, and 4, the passages 10 in the grenade body 2 are arranged in conical layers. Different layers may have different numbers of passages 10 according to the transverse diameter of the grenade body 2 at a given level. FIG. 4 illustrates twelve passages 10 extending radially from the central bore 3; however, a greater or lesser number of passages 10 may be provided, according to the propelling force available from the spring 6 employed, the diameter of the passages 10, and the viscosity of the colorant 9. Preferably, the passages 10 have a diameter which is inversely related to their length for equivalent flow resistance among the passages 10 so that the colorant 9 is dispersed with approximately uniform velocity in all directions.
The grenade 1 is set for operation by removing the plug 15, pivoting the delay levers 39 out of the bore 3, placing the spring 6 in the bore, and placing the piston 5 in the bore by extending the abutment disk 25 through the spring 6. The piston 5 is urged against the spring to extend the abutment disk 25 clear of the bore 3. The outer end 27 of the release lever is inserted under the abutment disk 25, and the hook 30 of the release lever is engaged with the pivot pin 28. The release lever 7 is employed to urge the piston assembly to its final position past the delay levers 39. A piston lever arm 54 of the release lever 7, extending between the pivot hook 30 and the point of contact between the end 27 and the abutment disk 25, is shorter than an opposite hand lever arm 25 of the release lever. The leverage provided by this relationship facilitates the final positioning of the piston assembly. The release lever 7 is then fixed in place by insertion of the release pin 33 through the tabs 31 and 32. A capsule 4 is inserted in the bore 3, and the plug 15 is replaced to complete the operational assembly of the grenade 1.
When the grenade 1 is to be used, it is held with the hand gripping the grenade body 2 and the release lever 7, and the ring 34 is grasped to remove the pin 33. When the grenade 1 is thrown, the release lever 7 separates from the grenade body 2 thereby disengaging the end 27 from the abutment disk 25. The spring 6 then urges the piston 5 toward the pellet 4 against the resistance created by the angular inertia of the wheels 42 of the delay mechanisms 8. When this inertia has been overcome, the piston 5 is driven forcefully against the pellet 4, rupturing it and forcing the colorant 9 toward the distribution channel 20 and, from there, out of the grenade body 2 through the dispersion passages 10. Because the dispersion passages 10 extend in approximately universal directions, successful dispersion of the colorant 9 is not dependent upon the orientation of the grenade 1 when it lands on the ground. Any opposing combatants marked by the colorant 9 are clearly discernible as casualties.
After use of the grenade 1, it may be cleaned by removal of the plug 15 and the other internal parts and immersion in water. Rearming of the grenade 1 may then be accomplished by the same steps as in the initial assembly described above.
While the present invention has been described and illustrated by the embodiment of the grenade 1, the arrangements of the components of the present invention are also applicable to other types of simulated weapons, such as paint dispersing "anti-personnel" mines and the like. Therefore, such other embodiments are intended to be encompassed within the spirit of the present invention.
It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.
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A paint dispersing training grenade includes a grenade body having dispersing passages extending between a central bore and an external surface of the grenade body, a plug threadedly received in one end of the bore, a piston resiliently urged by a spring toward the plug, a rupturable colorant containing capsule positioned between the piston and the plug, a separable release lever releasably pivotal on the grenade body and engaged with an abutment disk on a shaft extending from the piston, and an inertial delay mechanism engaged between the grenade body and the piston. The delay mechanism includes pivotable delay levers engaged with the piston at one end and having wheels rollably engaging a surface of the grenade body at another end. When the release lever is separated, movement of the piston by the spring is resisted by startup inertia of the wheels in rotating. When the inertia is overcome, the piston forceably ruptures the capsule and propels the colorant out of the grenade body through the dispersion passages.
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CROSS REFERENCE TO RELATED DOCUMENT
The present application is a division of application Ser. No. 10,087,236, filed on Mar. 1, 2002, now U.S. Pat. No. 6,703,746.
TECHNICAL FIELD
The present invention relates generally to electric or hybrid electric vehicle propulsion systems. More specifically, the present invention relates to the design of electric traction motors or machines for use in electric or hybrid vehicles.
BACKGROUND OF THE INVENTION
In today's automotive market, there exists a variety of electric propulsion or drive technologies used to power vehicles. The technologies include electric traction motors such as DC motors, AC induction motors, switched reluctance motors, synchronous reluctance motors, brushless DC motors and corresponding power electronics. Brushless DC motors are of particular interest for use as traction motors in an electric vehicle because of their superior performance characteristics, as compared to DC motors and AC induction motors. Brushless DC motors typically operate with a permanent magnet rotor. A permanent magnet rotor may be configured as a surface mount or interior/buried permanent magnet rotor. An interior permanent magnet (IPM) motor or machine has performance attributes, when compared to DC motors and AC induction motors, that include relatively high efficiency, relatively high torque, relatively high power densities, and a long constant power operating range which make an IPM machine attractive for vehicle propulsion applications.
Permanent magnets buried inside a rotor for a brushless DC motor exhibit high reluctance directly along the magnetic axis or the d-axis due to the low permeability of the permanent magnets. While along the q-axis, between the magnetic poles or magnetic barriers of an IPM rotor, there is no magnetic barrier and reluctivity to magnetic flux is very low. This variation of the reluctance around the rotor creates saliency in the rotor structure of an IPM machine. Therefore, the IPM rotors have reluctance torque in addition to the permanent magnet torque generated by the magnets buried inside the rotor. Reluctance in the d-axis can be created by one magnet such as found in a single barrier rotor design.
A single magnet of the one barrier rotor design can also be split into several layers creating a multi-barrier design. The multi-barrier design reduces leakage and improves the rotor saliency. Accordingly, motors having multi-barrier rotors have numerous performance advantages over a single barrier rotor design, including relatively high overall efficiency, extended high speed constant power operating range, and improved power factor. Improved saliency of the multi-barrier rotor helps to lower the amount of magnets or magnetic material in an IPM machine, as compared to a single barrier IPM machine or surface-mounted permanent magnet machine, by reducing dependency on magnetic torque. The amount of magnetic material needed to generate a specific torque and wattage rating depends on the level of saliency of the rotor. The higher the rotor saliency, the lower the magnetic material usage for the same overall machine performance. Electric motors having a multi-barrier rotor design, as compared to single barrier design, generate higher rotor saliency.
Magnets in an IPM machine can be pre-magnetized and then inserted inside the rotor. This magnet insertion is a complex and relatively costly step that adds manufacturing steps to the assembly of the IPM machine.
Post-magnetization of inserted magnetic material is possible if the magnets are inserted near the rotor surface. For post-magnetization, magnetic material may be preformed outside of the rotor, inserted into the rotor, and then magnetized. This is usually the case with sintered magnets, which require a certain orientation. A further type of magnetic material used that may be used in an IPM rotor is bonded magnets, which are usually mixed with a plastic, such as PPS, and may also be preformed outside of the rotor and then inserted into the rotor. However, generally bonded magnetic material is injected into the rotor cavities under high temperature and pressure.
Electric motors having multi-layer buried magnets in their rotors, as shown in FIG. 2 , exhibit excellent performance characteristics for vehicle propulsion application. The problems associated with post-magnetizing high energy magnetic material in such a barrier or rotor geometry would result in a large amount of magnetic material buried deep within the rotor that may only partially magnetize or not magnetize at all. The strength of a magnet is typically defined by the magnetic energy product (MEP). MEP is proportional to the product of magnetic remnant flux density, B r , and the coercivity, H c . MEP is measured in units of energy per unit volume. High energy magnetic material needs a relatively high magnetizing field during the magnetizing process. In present post-magnetization processes, the magnetizing field has difficulty reaching deep in the rotor because of the saturation of the magnetic circuit. Post-magnetization works efficiently for high energy magnetic material buried or located near the surface of the rotor, but for high energy magnetic material buried relatively deep in the rotor, post-magnetization is difficult due to the weakening of the magnetizing field.
SUMMARY OF THE INVENTION
The present invention includes a method and apparatus for the design of an IPM machine rotor. The present invention varies the type and strength of magnetic material in different regions of the rotor. In one embodiment of the present invention, NdFeB material or other high energy magnetic materials are configured in the entire outer barrier of the rotor of FIG. 2 where they may be easily magnetized. However, high energy magnetic material in the middle section or the inner regions of the rotor may not be exposed to a magnetizing field strong enough to fully magnetize a high energy magnetic material. In the present invention, low energy magnetic material is placed in those areas of the rotor that are difficult to magnetize, as they require a relatively smaller magnitude magnetizing field, as compared to the high energy magnetic material. Accordingly, the low energy magnetic material in the inner region may be fully magnetized. Low energy magnets in the inner region do not contribute to the air gap flux. However, the low energy magnets ensure bridge saturation, which is important to ensure high saliency corresponding to better performance. A non-magnetized high energy magnet in the inner region may contribute to a waste of valuable magnetic material and also inadequate bridge saturation. This inadequate bridge saturation will lower the rotor saliency and motor performance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic cross-sectional drawing of a permanent magnet motor and control system;
FIG. 2 is a cross section of a multi-layer interior or buried magnet motor geometry; and
FIG. 3 is a cross section of a multi-layer interior or buried magnet motor with bottom barriers filled with low energy magnetic material and upper barriers filled with high energy magnetic material.
DESCRIPTION OF THE PREFERRED EMBODIMENT
U.S. Ser. No. 09/952,319, assigned to assignee of this invention, includes a detailed description of multi-layer motor geometry and is hereby incorporated by reference in its entirety.
FIG. 1 is a diagrammatic drawing of a permanent magnet motor 10 having a wound stator 12 and permanent magnet rotor 14 . A power supply and inverter 16 commutate and control the speed and torque of the motor 10 in response to feedback including, but not limited to, an encoder, resolver, tachometer, proximity switch and tooth set, and back electromotive force (emf) detection. The motor may be characterized as a brushless DC motor with square wave or sinewave excitation provided by the power supply and inverter 16 .
FIG. 2 is a cross section of a multi-layer or barrier buried magnet rotor geometry. Regions 26 of the magnetic material layers or barriers 24 will be difficult to fully magnetize because of the distance from the rotor 14 surface. The magnetic material layers 24 surface may be magnetized by a magnetizing fixture or the wound stator 12 during a post-magnetization process. The post-magnetization process in one embodiment of the present invention includes positioning a magnetizing fixture around the rotor 14 to magnetize the magnetic material in the rotor 14 . Magnetizing fixtures similar to the stator 12 contain windings which are used for the magnetization process. The stator 12 may also be used to magnetize the rotor 14 instead of a magnetizing fixture in alternate embodiments of the present invention. The magnetizing fixture includes enough iron to prevent it from becoming saturated. Windings in the magnetizing fixture are placed such that the magnetic field is guided along a desired magnetization direction.
In a preferred embodiment of the present invention, magnetic powder mixed with plastic may be injected into the rotor 14 cavities under high temperature and pressure, allowing the material to bond and form inside the rotor 14 cavity. This process is desirable for large scale production. As mentioned earlier, post-magnetization of high energy magnetic material is currently only practical if the magnetic material is buried near the rotor surface.
Magnetic material, depending on its composition, requires varying magnetic field strengths to become fully magnetized. The high energy magnets which are preferred for variable speed motor drive applications due to their higher demagnetization strength require very high magnetic fields to saturate the magnetic material to become fully magnetized. The magnetic field is produced by the flow of current in the stator 12 winding or in a magnetizing fixture. Usually, a very high current burst is needed for a very short period of time to magnetize the rotor 14 . If the stator 12 lacks sufficient iron, it may become saturated during this process, preventing the generated magnetic field from penetrating into the rotor 14 .
As described previously, multi-layer or barrier geometry for an IPM rotor improves the rotor 14 saliency. Accordingly, the rotor 14 geometry of FIG. 2 has the advantage of having relatively high saliency, improving the machine torque density and lowering the magnetic material volume requirements for a specific torque or wattage motor rating. Lower magnetic material volume requirements reduce the motor cost and also alleviate the problems associated with high flux PM machines, such as short circuit and open circuit fault problems, and spin losses (eddy current induced losses) due to the presence of the permanent magnet field.
FIG. 3 is a cross section of a multi-layer or barrier buried magnet motor 10 with bottom barriers filled with low energy magnetic material 40 and upper barriers filled with high energy magnetic material 42 . The present invention removes high energy magnetic material from areas of the rotor 14 , such as regions 26 in FIG. 2 , where it is difficult to magnetize the high energy magnetic material and replaces the high energy magnetic material with a low energy magnetic material. The high energy magnetic material 42 may comprise a material requiring a magnetizing field more than 2000 kA/m to become magnetized. The low energy magnetic material 40 may comprise a material requiring a magnetizing field less than 2000 kA/m. Low coercivity of the low energy magnetic material 40 allows easier magnetization. In the preferred embodiment of the present invention, the high energy magnetic material 42 is NdFeB and the low energy magnetic material 40 is ferrite, but any other high energy or low energy magnetic material is considered within the scope of the present invention.
The low energy magnetic material 40 placed near the center of the rotor 14 can be fully magnetized by the magnetizing fixture because of its lower magnetizing field. The main performance contribution of the magnetic material 40 is to saturate the bridges 22 between barriers 24 and therefore ensure the saliency of the rotor 14 . These bridges 22 also ensure the mechanical strength of the rotor 14 . The mechanical strength of the low magnetic material 40 that is placed near the center of the rotor is sufficient to fulfill this function.
While this invention has been described in terms of some specific embodiments, it will be appreciated that other forms can readily be adapted by one skilled in the art. Accordingly, the scope of this invention is to be considered limited only by the following claims.
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An electric traction motor for a vehicle including a housing, a wound stator field located in the housing, a rotor magnetically interacting with the wound stator field, high energy magnets configured in the rotor, and low energy magnets configured in the rotor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of cooling hot briquetted sponge iron as well as an arrangement for carrying out the method.
2. Description of the Related Art
For the safe and economically justifiable transportation and storage of hot briquetted sponge iron, the latter must be subjected to cooling following upon the production of the sponge iron as immediately as possible.
To cool hot burnt material, for instance, sinters or pellets, it is known (AT-B358.617) to conduct the hot material through a shaft cooler and to direct cooling air through the shaft cooler in counterflow. To efficiently cool the material down to the final temperature desired, for instance ranging between 70 and 80° C., it is necessary to press a large amount of cooling air through the shaft cooler, to which end a high energy input is necessary. Furthermore, the high air speeds involved give rise to an increased discharge of material along with the cooling air emerging from the shaft cooler, in particular, if the grain size of the material is only very small.
From DE-C-29 35 707 it is known to cool hot briquetted sponge iron by introducing the same into a quenching tank, in which it is cooled to the final temperature desired. DE-C-29 35 707, furthermore, mentions that the quenching tank also may be replaced with an air cooling.
From DE-C-29 28 501 and DE-C-26 25 223 it is, furthermore, known to conduct hot briquetted sponge iron through a quenching tank by aid of a conveying belt, the sponge iron briquets incurring at a temperature of between 550 and 700° C. being cooled to approximately 80 to 90° C. After delivery of the sponge iron briquets from the quenching tank, the sponge iron briquets dry up by the residual heat present within the same.
Such known water cooling by immersion involves the disadvantage that the mechanical parts destined for the transport of the hot sponge iron briquets alternately get into contact with hot water having high contents of solids, CO 2 and suspended matter and with ambient air such that these parts are subject to intensive wear. Due to the very hot sponge iron briquets contacting cooling water, water gas reactions are likely to occur. Moreover, water cooling is poorly efficient due to the Leidenfrost phenomenon, which occurs very intensively in such a high temperature range. The insulating layer thus formed of water vapor on the surface of the sponge iron briquets has strongly adverse effects on the heat transfer in the high temperature range. In addition, the quality of the product will be deteriorated due to the still hot sponge iron briquets getting into contact with the cooling water, namely by material chipping off the sponge iron briquets. As a result, a very large amount of fine material incurs, which is detrimental to the functioning of mechanically moved parts of the conveying installations, etc., and frequently likewise is undesired in the further processing of the sponge iron briquets, in particular, in the further processing of sponge iron briquets.
From DE-C-29 28 501 it is, furthermore, known to charge a briquet strip onto a conveyor and spray the same with liquid, the briquet strip thus being cooled to a temperature ranging from 250 to 350° C. This, again, involves the above-described disadvantages, i.e., water gas reactions, the occurrence of the Leidenfrost phenomenon and hence non-uniform and insufficient cooling as well as thermal stresses and hence chipping off.
The briquetted sponge iron is to exhibit a high product quality, the formation of fine particles during cooling being avoided as far as possible. The arrangement for carrying out the method is to be subject to slight wear, thus having a long service life.
SUMMARY OF THE INVENTION
The invention overcomes the disadvantages of the prior art, such as those noted above, by providing methods and apparatus of cooling hot briquetted sponge iron which enable the troublefree progression of cooling at the optimum utilization of the capacity of the cooling means.
In accordance with the invention, this object is achieved by the combination of the following characteristic features:
the hot briquetted sponge iron, in a first cooling step, is passed exclusively by a gaseous cooling medium, preferably cooling air, while being gently cooled,
whereupon, in a second cooling step, the briquetted sponge iron is sprayed with a liquid cooling medium, preferably cooling water, thus being intensively cooled to the final temperature desired.
In doing so, the briquetted sponge iron, preferably during the second cooling step, additionally is passed by a gaseous cooling medium so as to provide for a particularly intensive contact between the sponge iron and the cooling medium.
Suitably, the hot briquetted sponge iron, during the first cooling step, is cooled to a temperature amounting to at least half the temperature of the hot briquetted sponge iron, preferably to a temperature below this temperature, which renders the use of the liquid cooling medium particularly efficient, primarily because the intensity at which the Leidenfrost phenomen occurs as well as its insulating effect are substantially slighter at lower temperatures than at high temperatures.
Preferably, the first cooling step is carried out over a longer period of time than the second cooling step, preferably over a period of time of more than 60% of the overall cooling time.
In order to ensure a particularly good contact between the gaseous cooling medium and the sponge iron, feeding of gaseous cooling medium, according to a preferred embodiment, is effected by pressing or sucking, the sponge iron being deposited on a gas-permeable support in the form of a bed.
A preferred mode of feeding liquid cooling medium to the briquetted sponge iron is realized by injecting liquid cooling medium into an air flow through nozzles. Again, it is feasible to largely avoid an insulating effect caused by water vapor forming on the surface of the sponge iron.
In order to reduce the load of dust on the cooling air and to save the arrangement, dust collection by exhaust ventilation advantageously is carried out prior to the first cooling step.
An arrangement for carrying out the method is characterized by the combination of the following characteristic features:
a gas-permeable support for the briquetted sponge iron, by which the sponge iron is capable of being moved through the arrangement,
a gas conduction means at least partially surrounding the support and destined for supplying a gaseous cooling medium to the briquetted sponge iron,
spraying nozzles for spraying a liquid cooling medium on the briquetted sponge iron,
the spraying nozzles being arranged only in the second half--viewed in the direction of movement of the support entraining the sponge iron--of the arrangement.
A preferred embodiment of the arrangement is characterized in that the support is comprised of a continuous conveying belt, such as a plate belt, whose upper belt side serves to receive the hot briquetted sponge iron.
Another preferred embodiment comprises a grating designed as a rotary cooler as the support for the sponge iron.
Preferably, the gas conduction means also extends over the area of the spraying nozzles.
Suitably, the support receiving the sponge iron passes through a dust extraction means after charging of the sponge iron and before entry into the gas conduction means.
To apply the liquid cooling medium, either mono-component or two-component nozzles are provided, both liquid cooling medium and gaseous cooling medium being feedable to the briquetted sponge iron via the latter.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be explained in more detail by way of the drawing, wherein:
FIG. 1 schematically illustrates a cooling arrangement according to the invention in the side view and
FIG. 2 illustrates the principal temperature course adjusting over the length of the cooling path
FIG. 3 shows the structural configuration of a cooling arrangement according to the invention, also in the side view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the embodiment represented in the drawing, FIG. 1, the cooling arrangement is equipped with a continuously and uniformly driven continuous conveying belt 1, such as a plate belt, whose upper belt side 2 serves as a support for hot sponge iron briquets 3. This sponge iron 3 is charged onto the gas-permeable continuous conveying belt 1 suitably in strip form, e.g., at a layer height 4 of about 200 mm and at a width corresponding to the belt width, such as, e.g., approximately 1000 mm. Charging of the sponge iron 3 is effected through charging chutes 5 in several layers so as to form a sponge iron strip 9 as uniform as possible.
When moving the sponge iron 3 in the direction of arrow 6 by entrainment with the continuous conveying belt 1, the sponge iron, at first, is guided through a dedusting zone 7, which comprises a hood 10 connected to a dust exhaust ventilation 8 and covering the sponge iron strip 9. In the dedusting zone, the fine material adhering to the surfaces of the sponge iron particles, such as, e.g., on the surfaces of the briquets, is removed by suction.
After this, the sponge iron strip 9 is moved through an air cooling zone 11, in which the hot sponge iron 3--which has a temperature T A ranging between 580 and 720° C. when being deposited on the continuous conveying belt 1--is cooled to about 350° C. exclusively by aid of cooling air, according to FIG. 1 by aid of cooling air pressed through the sponge iron strip 9 from below. The cooling air is compressed by means of a compressor 12 and is supplied to the upper belt side 2 via an air conduction means 13 in a manner that the air is forced to flow through the sponge iron strip 9.
The cooling air system comprises a sound absorber, a volume flow control means as well as collecting and distributing channels not illustrated in detail, including the necessary shut-off devices and control means.
In the approximately third third of the upper belt side 2 a water cooling zone 14 is provided, in which the sponge iron 3 is intensively cooled to a surface temperature of approximately 85° C. by means of sprayed-on water. Water spraying is effected via a distribution system 15 through several spraying nozzles 16, which are designed either as one-component nozzles or as two-component nozzles. If two-component nozzles are employed, these are fed with treated water and compressed air.
According to the embodiment illustrated in FIG. 1, the air supply also extends over the water cooling zone 14 such that an additional cooling effect by cooling air is achieved in the water cooling zone 14.
The air pressed through the hot sponge iron 3 and the vapor forming are collected in an exhaust hood 17 and are carried off via an exhaust ventilation including a purification means not illustrated in detail.
After the sponge iron 3 has left the continuous conveying belt 1 and is conveyed further via a discharge chute 18, drying of the sponge iron 3 is effected by the residual heat still contained within the same.
From FIG. 2, the particularly high efficiency of the cooling method according to the invention is clearly apparent. The temperature course on the surface of the sponge iron 3 over the length of the cooling arrangement is indicated by full, uninterrupted line I. It can be seen that the sponge iron 3 undergoes gentle and careful cooling in the air cooling zone 11, in which cooling is effected exclusively by air. It is only when the sponge iron 3, by exclusive air cooling, has reached a temperature amounting to approximately half of the initial temperature T A or less that the invention provides for water cooling, which causes relatively harsh and intensive cooling of the sponge iron 3 as compared to air cooling. The final temperature of the sponge iron 3 thereby reached after a relatively short cooling period is denoted by T E .
The temperature course of the sponge iron 3 that would occur with exclusive air cooling over the total length of the upper belt side 2 is illustrated in FIG. 2 by broken line II. The final temperature T' E of the sponge iron attained in that case clearly lies above the final temperature T E attained according to the invention. In order to be able to attain the final temperature T E according to the invention exclusively by air cooling, the arrangement would have to extend over a substantially greater length and/or the air flow rate would have to be substantially increased in terms of quantity and the layer height 4 of the sponge iron strip 9 and hence the specific flow rate would have to be reduced.
A cooling curve that would result from cooling of the sponge iron 3 if the sponge iron 3 in an initial zone were sprayed exclusively with liquid cooling medium, i.e., cooling water, is illustrated in FIG. 2 by dot-and-dash line III. It will be appreciated that, at first, harsher cooling occurs than with air, but that, due to the occurrence of the Leidenfrost phenomenon to an increased extent, the effectiveness of cooling cannot come up to that of the cooling effect according to the invention, i.e., the final temperature T" E attainable exclusively by means of liquid cooling medium likewise lies above the final temperature T E attained according to the invention; thus, the cooling arrangement would have to be designed longer and the sponge iron would have to be exposed to cooling medium over a longer period of time also in that case.
In addition, there is the danger of water gas reactions forming and of product qualities deteriorating, because harsh cooling in the high temperature range T A with sponge iron may lead to chipping off and hence to the formation of fine portions in inadmissible amounts.
The invention is not limited to the exemplary embodiment illustrated in the drawing, but may be modified in various aspects. It is, for instance, possible to replace the continuous conveying belt 1 with a rotary cooler comprised of a gas-permeable grate and rotating slowly, wherein the sponge iron deposited on the grate, during a rotation of the grate, for instance by 260°, is cooled by means of cooling air and subsequently by means of cooling water. Furthermore, it is also possible to realize air cooling merely in the air cooling zone 11 and to operate exclusively with one-component or two-component nozzles in the consecutively arranged water cooling zone 14. The cooling air may be directed through the sponge iron belt 9 from bottom or from top by suction or pressing.
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In order to attain as low a final temperature as possible after as short a period of time as possible in a method of cooling hot briquetted sponge iron (3) under optimum utilization of the cooling medium, the hot briquetted sponge iron (3), in a first cooling step (11), is passed exclusively by a gaseous cooling medium while being gently cooled and subsequently, in a second cooling step (14), is sprayed with a liquid cooling medium, thus being intensively cooled to the final temperature desired.
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1. FIELD OF INVENTION
[0001] The invention relates an improved musical instrument bow having different sections of hair identified, a modular hair device for use in the improved musical instrument bow, and a method of teaching use of a stringed instrument using the improved musical instrument bow.
BACKGROUND OF THE INVENTION
[0002] Stringed instruments, such as the violin, viola, cello, and bass are typically played using a bow. The bow consists of a bowstick having a frog at one end and a tip at an opposing end. Hairs are held between the frog and tip of the bowstick. At the tip end of the bowstick, the hairs are usually held in place by inserting an end of the hairs into a hole and then inserting a plug into the hole. At the frog end of the bowstick, the hairs are usually mounted to a ferrule on the frog and the entire frog moved relative to the tip by use of a screw device to apply tension to the hairs. Alternatively, the hairs can be passed through a ferrule and then wound on a screw device used to apply desired tension to the hairs. Rosin is usually applied to the hairs to provide tackiness and heighten friction between the hairs and instrument strings.
[0003] During play of the stringed instruments different sections of the hairs must contact the strings. For example, strong sound is usually produced by contacting a center section of the hairs with the strings. In the playing of staccato one usually uses the tip or base sections of the hairs. Students learning to play stringed instruments have difficulty distinguishing the different sections of the hairs to contact the strings. Furthermore, teachers also have difficulty showing students where the different sections on the hairs are delineated. Often tape or other marks are made on the bowstick to show approximately where on the hairs the different sections are located. However, such marks on the bowstick are far removed from the hairs and, thus, there still remains ambiguity as to where on the hairs the sections are delineated.
[0004] There are many known devices for use in teaching students how to use a bow on stringed instruments, as shown in U.S. Pat. Nos. 6,977,600; 5,670,727; 5,355,757; 5,301,589; 4,854,212; and Des. 322,270. However, the devices are difficult to adapt to different sized bows and techniques, and do not provide an efficient and easy method for distinguishing the different sections of the bow hairs.
[0005] U.S. Pat. No. 6,280,654 discloses the use of glow in the dark rosin that is suitable for use on violin bow strings. However, this patent does not teach or suggest using the rosin to identify different sections of the bow hairs.
[0006] There is a need for a simple and effective way to unambiguously distinguish the different sections of hairs mounted on a bow.
SUMMARY OF INVENTION
[0007] An objective of the present invention is to provide a simple and effective way to unambiguously distinguish different sections of the hairs of a musical instrument bow.
[0008] Another objective of the present invention is to provide a simplified modular hair device.
[0009] A further objective of the present invention is to provide a simple and effective method for teaching students how to play stringed instruments.
[0010] These objectives and other objectives are met by a musical instrument bow comprising:
[0011] a plurality of hairs having playing sections of the hairs identified to distinguish different playing sections of the hairs that contact strings of a musical instrument during playing of the instrument; and
[0012] a bowstick constructed and arranged to hold the plurality of hairs, the bowstick having a frog at one end and a tip at an opposing end, the plurality of hairs being held between the frog and tip.
[0013] The above objects are also met by a modular musical instrument bow hair device comprising:
[0014] a plurality of musical instrument bow hairs having playing sections thereof identified; and
[0015] a first binder at one end of the hairs for binding the hairs and preventing relative movement among the hairs.
[0016] The above objectives are also met by a method of teaching use of a stringed instrument comprising:
[0017] instructing a student to contact a stringed instrument with different playing sections of bow hairs, wherein the different playing sections of the bow hairs are identified to distinguish the playing sections from one another.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 illustrates a musical instrument bow having different sections of the hairs identified; and
[0019] FIG. 2 illustrates a modular musical instrument bow hair device.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] The invention will be described with reference to the attached Fig.s without being limited thereto.
[0021] FIG. 1 illustrates a musical instrument bow 1 having a bowstick 2 . The bowstick 2 has a tip 4 at one end and a frog 6 at an opposing end. The frog 6 is located near the base 10 and finger rest 12 of the bow and usually has an eye 8 . A plurality of hairs 14 are held between the frog 6 and tip 4 . At the tip 4 , the hairs 14 are held in place by inserting an end of the hairs 14 into a hole 5 and then inserting a plug into the hole 5 . While a hole 5 and plug are shown, any suitable structure for fastening the hairs 14 to the tip 4 can be used. At the frog 6 , the hairs 14 are fastened to a ferrule 7 . Alternatively, the hairs can be passed through a ferrule and then wound on a screw device (not shown). The fastening of the hairs 14 to a frog 6 is now well known and any means for fastening the hair to the frog can be utilized as desired. A screw device 9 is used to apply desired tension to the hairs 14 by moving the frog 6 closer or farther from tip 4 depending on the direction the screw device 9 is turned. However, any suitable means for tensioning the hairs 14 can be utilized as desired, even the tensioning means shown in U.S. Pat. No. 5,918,297.
[0022] Different sections of the hairs 14 are identified so that they can be easily distinguished from one another, for example, by color. As shown in FIG. 1 , for example, three sections are identified, the base section 20 , the center section 22 , and the tip section 24 . The term sections is understood to mean different portions of the hairs 14 in a lengthwise direction when they are mounted between the frog 6 and tip 4 . While three sections are preferred, more or less sections can be identified using the present invention, with two sections being the minimum number.
[0023] Preferably, the sections 20 , 22 and 24 are identified using colors. When only colors are used to distinguish sections, adjacent sections should be different colors. While use of colors is preferred, the different sections can be identified as desired using any combination of marks such as numbers, lines, letters, colors, patterns, etc. Preferably, the marks on the hairs do not interfere with or substantially alter playing of the instrument.
[0024] If desired, an up section 28 of hairs 14 can be identified according to the present invention and a down portion 26 of hairs 14 left unmarked, since the down portion 26 is usually covered with resin. The down portion 26 of hairs is well known to be those hairs that contact the strings and the up portion 28 are those that are visible to the player.
[0025] Preferably, the exact center of the hairs is marked with a line 30 .
[0026] While a plurality of hairs 14 has been shown and are preferred, the invention is application to a single string bow. Furthermore, the hairs 14 can be formed from any desired synthetic or natural material as desired. Preferably, the hairs 14 comprise horse hair.
[0027] The hairs 14 can be identified using any conventional method of applying markings, such as dying, screening, printing, coloring, and drawing, as desired, which are well within the skill of those skilled in the art.
[0028] Loose hairs 14 are difficult for students install on the bowstick 1 and, thus, often instructors or professional specialist technicians must install the hairs 14 . With the addition of indentifying sections of the hairs 14 according to the present invention, the installation of the hairs 14 is now even more difficult since the sections of individual hairs 14 must be aligned before mounting them on the bowstick 2 .
[0029] As shown in FIG. 2 , the invention also provides a musical instrument bow hair device 35 comprising bound hairs 14 , such that the individual hairs cannot move relative to one another. The hairs can be bound at one end or at both ends using binders. In this manner, the bound hairs can easily be installed on the bowstick 2 . The binder(s) can further have the function of a mount for the hairs to the bowstick 2 . For example, instead of using a hole and plug at the tip, the hairs 14 can inserted in a hole and a first binder 40 at one end of the hairs 14 used to bind the hairs to the tip 4 . A second binder 42 at the other end of the hairs can be used to bind the hairs 14 to the frog 6 . In this embodiment, the second binder 42 is capable of passing through the hole 5 at the tip 4 , whereas the first binder 42 cannot pass through the hole 5 . For example, simple crimping binders can be used. Other binding means can also be used as desired, such as fasteners, clamps, clasps, screws, glues, and melts. Other means for mounting the first binder 40 to the tip can also be used, such as screws, clamps, notches, and clasps, as desired. Similarly, any desired means for mounting the second binder 42 to the frog 6 can be used.
[0030] While the claimed invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one of ordinary skill in the art that various changes and modifications can be made to the claimed invention without departing from the spirit and scope thereof.
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Provided are an improved musical instrument bow having different sections of hair identified, a modular hair device for use in the improved musical instrument bow and a method of teaching use of a stringed instrument using the improved musical instrument bow.
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[0001] This application claims priority under 35 U.S.C. §119 to U.S. Provisional Application No. 61/782,941, which was filed on Mar. 14, 2013, and is herein incorporated by reference in its entirety.
BACKGROUND
[0002] Percutaneous introduction of the needles and catheters into the deep vessels (jugular, subclavian, femoral and other) requires detailed knowledge of the anatomy of the region and specialized training.
[0003] The insertion can be associated with numerous potential complications including: bleeding, lacerations of the neighboring arteries or veins, injury to the nerves, pneumothorax and death.
[0004] Recently, use of ultrasound for guiding the insertion has improved the safety of those procedures. However, presently available ultrasonic transducers and ultrasonic systems require triangulation of the needle insertion in relation to the ultrasonic image. Further, the quality of the image presented to the user during such procedure is poor (grainy and with poor resolution). Thus, additional ultrasonic image interpretation training is necessary for any user attempting to perform ultrasound guided insertion of the needle.
SUMMARY
[0005] Various embodiments are directed to a disk-shaped probe having an ultrasonic transducer and a central channel or opening within the disk to accommodate a needle (including, for example, a penetration sensor-equipped needle) or other instrument, such as a catheter. The probe may be used for guided introduction or insertion of the instrument, via the central channel, into a vessel or other anatomical structure of a patient. Some embodiments provide a computer-enhanced graphic image of the vessels and other structures in the area covered by ultrasonic probe. The image may be used, for example, by a user for manually positioning and orienting the instrument, using the probe, with respect to the target structure so that the tip of the instrument can be introduced or inserted into the desired area.
[0006] The size and location of the structures in the image can change as the user moves the probe around the area to determine the optimum needle insertion point and/or angle. Additionally, in some embodiments, a crosshair, or other suitable symbol, can be located in the center of the image indicating exact point of the penetration of the vessel or other structure when the needle is inserted through the channel in the center of the transducer. In some embodiments, data from the sensor-equipped needle can be transmitted during insertion of the needle and incorporated into the image on the screen, which gives a user indication that the tip of the needle has reached the lumen of the vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:
[0008] FIG. 1 is a perspective view of an example of an ultrasonic transducer, in accordance with an embodiment.
[0009] FIG. 2A is a perspective view of the ultrasonic transducer of FIG. 1 .
[0010] FIG. 2B depicts one example of a graphical image representing a structure detected by the ultrasonic transducer of FIG. 1 , in accordance with an embodiment.
[0011] FIG. 3A is a perspective view of the ultrasonic transducer of FIG. 1 .
[0012] FIG. 3B depicts another example of a graphical image representing a structure detected by the ultrasonic transducer of FIG. 1 , in accordance with an embodiment.
[0013] FIG. 4A is a perspective view of the ultrasonic transducer of FIG. 1 .
[0014] FIG. 4B depicts yet another example of a graphical image representing a structure detected by the ultrasonic transducer of FIG. 1 , in accordance with an embodiment.
[0015] FIGS. 5, 6 and 7 are different perspective views of an example of an ultrasonic transducer, in accordance with an embodiment.
DETAILED DESCRIPTION
[0016] FIG. 1 depicts an example of a needle-accommodating ultrasonic probe, or transducer 100 , according to an embodiment. It will be appreciated that, according to various embodiments, various instruments, such as needles, catheters and the like, can be utilized, and the present disclosure is not intended to limit such instruments to needles. The transducer 100 may include, for example, a flat disk approximately 2 cm to 5 cm thick connected by the lateral power/data cord 102 to an external ultrasound unit 104 . The thickness of the disk can be varied to accommodate various needles or other instruments such that the needle or instrument is stably aligned when inserted through the disk for guiding the introduction of the needle or instrument into an anatomical structure of a patient, such as described below.
[0017] The disk/transducer 100 can contain two or more linear arrays 106 of crystal (also referred to herein as transducer elements) that emit and then receive ultrasonic sound waves. For example, the ultrasonic transducer 100 may include a disk that contains two or three linear arrays 106 that are parallel to each other and located approximately 1 cm apart. The disk/transducer 100 includes an opening 108 or channel passing through the disk for accommodating the passage of a needle or other instrument, and a sterile channel, sleeve, sheet or other material (not shown in FIG. 1 ) for separating the transducer disk 100 from the instrument and for providing a sterile environment for the portion of the instrument passing through the opening 108 . The opening 108 may, for example, be oriented substantially perpendicular to a surface 112 of the disk/transducer 100 . In some embodiments, the disk 100 includes a split 110 forming two portions or halves that can be separated from each other. The split 110 may pass through or adjacent to the opening 108 , as shown, for example, in FIG. 5 .
[0018] FIG. 2A depicts another view of the transducer 100 , and FIG. 2B depicts an example of a graphical image 200 generated from signals received by the transducer. The arrays 106 can be configured to fire sequentially such that each array 106 transmits and receives ultrasonic signals independently of and without interference by the other arrays. The ultrasound image can be rendered as two or three images 202 , 204 , 206 of the area underneath the transducer 100 . Each image 202 , 204 , 206 may, for example, include a graphical representation of at least a portion of the vessel or other structure detected by the corresponding array 106 . The graphical representation may be, for example, an artificial or simplified representation of the actual vessel 120 or other structure being imaged (e.g., not a literal representation of the actual vessel).
[0019] The images 202 , 204 , 206 can be summarized (e.g., in an overlay or additive manner) on a display 208 and presented in the form of graphic image of the target area (e.g., the vessel 120 or other structure) by a processor. If the arrays 106 are aligned at approximately 90 degrees to the longitudinal axis 122 of the vessel 120 , the images 202 , 204 , 206 will be almost identical. The images 202 , 204 , 206 can then be graphically summarized on the screen 208 showing a segment of the vessel 120 user is trying to access and a cross-hair 210 or other marker indicating an executable needle insertion site. The cross-hair 210 may, for example, indicate the point of penetration of the needle or instrument into the vessel or other structure if the needle is inserted through the opening 108 . If the transducer 100 is not aligned at 90 degrees to the longitudinal axis of the vessel, the graphic summary will not be displayed and there will be no executable needle insertion site, such as shown in FIGS. 3A and 3B (zero degrees), and FIGS. 4A and 4B (between zero and 90 degrees), where the disk/transducer 100 is oriented at an angle other than 90 degrees. In use, manual manipulation of the transducer 100 for adjusting the position and angle can ultimately align longitudinal axis of the vessel at 90 degrees to the transducer and that will create executable needle insertion site.
[0020] In some embodiments, the disk/transducer 100 can be constructed to orient the needle at substantially perpendicular to (e.g., approximately 90 degrees) or at an angle other than 90 degrees (e.g., any angle between zero and 90 degrees) with respect to the longitudinal axis of the vessel 120 or other structure. For instance, the opening 108 may be formed at an angle other than 90 degrees with respect to the surface 112 of the disk/transducer 100 .
[0021] FIGS. 5, 6 and 7 are perspective views of various examples of the transducer 100 . In some embodiments, the disk/transducer 100 has open channel 108 at the center able to accommodate sterile sheet or sterile tube 130 to allow insertion of a needle 140 or catheter in the sterile fashion. The channel 108 is at 90 degrees to the surface plane 112 of the disk/transducer 100 . The disk/transducer 100 can, in some embodiments, be divided into hinged halves, or other suitable portions of the circle allowing opening of the disk/transducer 100 to allow insertion of the sterile sheet or tube 130 into the center opening 108 of the disk/transducer 100 , after such insertion the disk/transducer 100 can be closed and ready to use. Such splitting of the disk/transducer 100 advantageously facilitates ease of access to the center opening 108 for inserting or removing the sterile tube 130 and for removing the disk/transducer 100 from the needle 140 after the needle has been inserted into the patient.
[0022] In use, a user can take the disk/transducer 100 and place it at the surgically prepped desired region of the patient for the particular vascular or other access. Sterile ultrasonic coupling gel may be used between the disk/transducer 100 and the skin of the patient. The user can scan the area under the transducer 100 by manipulating the position, location and the angle of the disk/transducer 100 pressed against the skin. The image on the monitor can display the underlying structures with the cross-hair symbol 210 hovering in the center of the image if the disk/transducer 100 is properly aligned with the underlying vessel 120 or structure. Once the suitable insertion point is identified, the user can insert the needle 140 through the sterile channel 130 in the center of the disk/transducer 100 and advance it until the lumen of the vessel 120 or other desired structure is reached. The reaching can be confirmed by a sensor signal in the needle 140 , or by the withdrawal of blood or fluid through the needle. Once the insertion is confirmed, the disk/transducer 100 can be opened (i.e., the split portions separated from each other), decoupled from the needle 140 and removed from the field.
[0023] Having thus described several exemplary embodiments of the disclosure, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. For example, a computer-enhanced image of the target vessel, organ or other structure, such as the image in display 200 described above with respect to FIGS. 2B, 3B and 4B , can simplify insertion decision making process for the user and reduce the amount of additional training required to perform the procedure. Two- or three-dimensional color or black and white graphic representations of the structures in the region can, in some embodiments, replace conventional black and white grainy ultrasonic images. In some embodiments, gender and weight specific databases of the structures for the particular region (e.g., femoral triangle, neck, subclavian region) can be pre-loaded to a memory of a logic unit or processor. After the user keys in the insertion region and inputs patient gender and weight, stored data can be preloaded as a base matrix. Real-time ultrasound generated data can be then incorporated into the matrix and imaged into the graphic on the screen.
[0024] Accordingly, the foregoing description and drawings are by way of example only.
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An ultrasound probe system for guiding introduction of an instrument into a patient includes a disk having a surface and an open channel passing axially through the disk and at least two ultrasound transducer elements disposed on the surface of the disk in a parallel arrangement. The open channel is configured to receive the instrument therethrough to permit alignment of the instrument with respect to the disk. Each of the ultrasound transducer elements is configured to transmit and receive ultrasonic waves for detecting an anatomical structure. A graphical representation of at least a portion of the anatomical structure can be provided for guiding the introduction or insertion of the instrument into the anatomical structure.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a table and more particularly to a table which is mounted on an automobile trunk enclosure.
2. Description of the Prior Art
An activity which has grown in popularity over the past several years, includes the gathering of fans at their automobiles for eating and dining prior to certain athletic events. Such picnics are particularly common at football games and have become frequently known as "tail-gate" parties. Since the tail gate parties frequently occur in parking lots, dining tables are not normally readily accessible. Thus, people store their food and beverages in their trunks and "eat out of their trunks." Others open foldable tables, which are stored in their automobile trunk, and set food and drink on the tables which are positioned adjacent to the rear of the automobile.
Such picnics may also be enjoyed in various remote areas, such as a woods, picnic grounds, amusement parks, etc.
DESCRIPTION OF THE PRIOR ART
The apparatus constructed according to the present invention comprises a table which can be mounted on the rear wall of a trunk enclosure. U.S. Pat. No. 4,494,465 issued to Charles M. Fick, Jr., on Jan. 22, 1985, discloses a prior table for mounting on an automobile trunk, however, it incorporates a rather complicated leg arrangement for supporting the table on the ground. It frequently occurs that, at the areas where "tail-gaters" eat and dine, the ground surface is uneven, soft and otherwise not readily adaptable for mounting a table leg. U.S. Pat. No. 3,011,847 issued to R.C. Rader on Dec. 5, 1961, disclose a trunk mounted automobile table which necessitates modification of the automobile by mounting hooks in the bott.om wall of the trunk enclosure. Such hooks are relatively complicated to install, unsightly and interfere with luggage storage. The apparatus constructed according to the present invention contemplates a table which is cantileverly mounted on the trunk so that no vertical support legs are necessary for mounting in the trunk or for supporting the table on the ground.
Other prior art U.S. patents known to applicant are as follows:
______________________________________U.S. Pat. No. PATENTEE ISSUE DATE______________________________________2,451,275 J. M. Cercownay Oct. 12, 19482,718,445 E. A. Wilson Sep. 20, 19552,721,777 J. L. Willis Oct. 25, 19552,833,608 J. C. Tobias May 6, 19583,709,159 Oglesby, Jr. Jan. 9, 19733,896,742 Ferraro Jul. 29, 19754,418,626 Semien Dec. 6, 19834,452,151 Jarrard Jun. 5, 1984______________________________________
It is an object of the present invention to provide a new and novel tail gate table.
It is another object of the present invention to provide a new and novel table for mounting on a trunk enclosure of an automobile.
It is a further object of the present invention to provide a new and novel table for mounting on an upstanding rear wall of a trunk enclosure.
It is a further object of the present invention to provide the new and novel tail gate table which is cantileverly mounted on a rear wall of an automobile trunk enclosure.
A further object of the present invention is to provide a new and novel tail gate table which is cantileverly mounted on a rear wall of a trunk enclosure and which can be longitudinally adjusted to any selected one of a plurality of different front-to-rear spaced positions.
Other objects and advantages of the present invention will become apparent to those of ordinary skill in the art as the description thereof proceeds.
SUMMARY OF THE INVENTION
A tail gate table for mounting on an automobile trunk enclosure having an upstanding rear wall comprising a table top and cantilever mount mechanism depending from the table top and adapted to receive the rear wall for cantileverly mounting the table top on the upstanding rear wall.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention-may be more readily understood by referring to the drawings, in which:
FIG. 1 a side sectional view, taken along the line 1--1 of FIG. 2, of a table, constructed according to the present invention, mounted on an upstanding rear wall of an open automobile trunk;
FIG. 2 is a top plan view of the table constructed according to the present invention, taken along the line 2--2 of FIG. 1, parts of the table top being broken away to better illustrate a portion underlying mounting structure; and
FIG. 3 is a rear end sectional view thereof, taken along the line 3--3 of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
A tail gate table, generally designated 10, constructed according to the present invention, is particularly adapted for use with an automobile (not shown) having an automobile trunk enclosure, generally designated 12, including opposed side walls 14 spanned by a rear upstanding wall 16 and a bottom wall 18. A top trunk deck lid (not shown) which includes a depending rear wall portion that complements rear wall portion 16, completes the trunk enclosure as usual. The automobile also includes a rear bumper 21 having a top wall 19 as usual. The trunk enclosure 12 defines an internal compartment 20 in which the table 10, when not in use, as well as luggage, food, etc. can be stored.
The table 10 includes a table top, generally designated 22, including a generally planar panel 24, having a predetermined thickness 25, and an integral perimetrically extending retaining flange, generally designated 27. The flange 27 is illustrated as having an inverted U-shaped cross section, and includes an annular inner side wall 26 integral with a bottom wall 26a , an annular integral horizontal, parallel, top wall, generally designated 28, and a downwardly extending, integral annular outer wall 30. The top wall 28 includes a pair of generally parallel top, wall side portions 28a of a predetermined width W and a pair of generally parallel, horizontal, end wall portions 28b of a greater predetermined width X. A plurality of recessed portions or cup receiving wells 33 are provided in the end top wall flange portions 28b for receiving drinking containers (not shown).
The table top 22 is mounted on the upstanding trunk wall 16 via a cantilever mount, generally designated 31. The cantilever mount 31 includes a pair of longitudinally extending slides or rails 36 slidingly, snuggly, frictionally received by a pair of laterally spaced, downwardly opening T-shaped slots, generally designated 40, provided in the bottom wall 42 of the panel 24. A brace member 49a spans the legs 49 to improve rigidity of the table. The slots 40 each have a main slot portion 39 of a predetermined width 43 and a reduced lower neck 41 of a lesser width 45 which communicate with one of the main slot portions 39 along the length of the bottom wall 42.
The cantilever mount 31 includes a pair of longitudinally spaced front and rear mount legs 46, 49 respectively, coupled to the underside of each of the slides 36. The front to rear distance 47 between the depending mount legs 46, 49 in each pair is sufficient to freely receive therebetween a trunk wall 16 of various thicknesses 56.
To insure that the table 10 is secure when the trunk wall thickness 56 is relatively thin, a threaded clamping rod 48 is threadedly mounted in the front mount leg 46 for engaging the inside surface 50 of the upstanding trunk wall 16 to urge the rear mount leg 49 forwardly, in the direction of the arrow 52, into tight clamping engagement with the outer surface 53 of the trunk wall 16. The inner surface 55 of the outer mount leg 49 may be lined with a layer 57 of fabric, felt or other material which will not mar the outer trunk surface 53.
It should be noted that the rearward or outermost leg 49 of each pair of legs is of sufficient vertical length that the lower terminal edge E thereof bears on the upper surface 19 of the bumper 21.
The leg 49 includes an upper rod portion 51 and a lower hollow cylindrical leg 54 telescopingly received thereon for vertical adjustment. A thumb screw 55 is threaded through the sidewall 60 of the cylindrical leg portion 53 to selectively secure the leg portions 51, 53 together in any selected one of a plurality of different vertically adjusted positions.
The rails 36 are snuggly, slidingly, frictionally mounted in the slots 40 such that the table 10 can be moved forwardly, in the direction of the arrow 52, or rearwardly in a direction of the arrow 54 to any selected one of a plurality of different longitudinally spaced positions relative to the rear wall 16 and the cantilever mount means 31. Because of the tight frictional relation between the rails 36 and the slots 40, the table 10 will tend to remain stationary in any of the longitudinally adjusted positions.
OPERATION
The table 10 can typically be stored in the trunk enclosure 12. When it is desired to use the table 10, the clamping screw 48 is turned out of the inner depending leg 46 and the legs 46 and 49 are disposed on opposite sides of the rear trunk wall 16. The thumb screw 59 is turned out of the bottom cylindrical leg portion 58 which is vertically adjusted relative to the upper rod portion 51 so that the lower terminal edge E thereof is supported by the bumper top wall 19, as illustrated in FIG. 1. The screw 59 is then tightened. The screw 48 is then turned inwardly to the position illustrated in FIG. 1 to engage the inner surface 55 of wall 16 to force the other leg 49 forwardly into clamping engagement with outer surface 53 of the trunk wall 16. The table top 22 can be moved relative to the trunk enclosure 12 by sliding the panel 24 relative to the guide rails 36.
When the tail gate party is finished, the users need merely unclamp the screws 48 and return the table 10 to the trunk enclosure.
It is to be understood that the drawings and descriptive matter are in all cases to be interpreted as merely illustrative of the principles of the invention, rather than as limiting the same in any way, since it is contemplated that various changes may be made in various elements to achieve like results without departing from the spirit of the invention or the scope of the appended claims.
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A tailgate table for mounting on the rear upstanding wall of an automobile truck enclosure including: a table top, and mount mechanism depending from the table top to receive the rear wall for cantileverly mounting the table top on the upstanding rear wall.
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BACKGROUND
1. Field of the Invention
The present invention relates to a flat bed knitting machine with at least two carriages arranged on an elongated needle bed, the two carriages being reciprocally driven along the needle bed to produce knitted fabrics.
2. Description of the Related Art
Flat bed knitting machines generally include an elongated needle bed usually consisting of front and rear needle assemblies and a carriage which slides over the needle bed. With this arrangement, knitted fabrics can be knitted, the maximum width of which corresponds to the operative width of the needle bed. Typically, such flat bed knitting machines have a needle bed whose width is about 100 cm to 230 cm to accommodate the largest knitted fabric envisioned.
A single carriage provided on a needle bed has long been recognized as wasteful when the machine is only used to produce a knitted fabric of the maximum width. A solution that has been proposed provides two carriages on the needle bed, each carriage performing the same knitting task as the other carriage but at a separate areas of the needle bed. This permits two identical knitted fabrics to be produced, each having a maximum width of slightly less than one-half the operative width of the entire needle bed, that is, approximately 100 cm each. (The reduction from exactly one-half corresponds to the space which must be maintained between the knitted fabrics to insure that one carriage does not affect the stitches in the fabric knitted by the other carriage.)
For example, U.S. Pat. No. 4,640,103, issued to Hans Schreiber on Feb. 3, 1987, describes a double carriage flat bed knitting machine in which one carriage is selectably removable. When both carriages are present, the knitting stroke is shortened, thereby permitting two identical knitted fabrics to be produced. When only one carriage is present, the entire operative width of the needle bed is available for the production of a knitted fabric. This patent is said to provide the advantages of both a single- and a double-carriage knitting machine.
Whatever advantages might be obtained from the arrangement shown in U.S. Pat. No. 4,640,103, still only one knitted fabric, or two identical knitted fabrics, may be produced. This limits the type of knitted fabric that may be produced by such knitting machines to those fabrics producible by a single head, and makes production of certain weaves (for example, cabling and other complex stitch constructions) very difficult.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a flat bed knitting machine capable of overcoming these and other difficulties now found in the art.
It is a further object of the present invention to provide a flat bed knitting machine having a plurality of carriages arranged on a needle bed, the carriages being independently driven both as to direction and as to length of reciprocal stroke.
It is a further object of the present invention to provide a flat bed knitting machine having a plurality of carriages arranged on the needle bed, individual ones of the carriages being independently driven across the whole length or any part of the whole length of the machine in both directions using the whole length or any part of the machine without interfering or colliding with each other. The speeds at which the carriages are driven are totally independent of each other.
It is a further object of the present invention to provide a flat bed knitting machine in which a plurality of carriages arranged on a needle bed are operable to produce two or more different knitted fabrics, or are cooperable to produce a single knitted fabric in the same area of the needle bed.
These and other objects of the present invention are obtained by the provision of a flat bed knitting apparatus in which a plurality of carriages are provided on a needle bed, each of the carriages mounted for movement in a longitudinal direction of the needle bed. Plural driving means, one corresponding to each one of said plurality of carriages, are provided for the carriages, each of the driving means for reciprocally driving its corresponding carriage on the needle bed, and each of the driving means being operable independently with respect to the other driving means. A controller is provided that is operable to control the driving means and the carriages so that each carriage can execute a different knitting task. Preventing means are also provided to prevent the carriages from interfering with each other. Variable take-up means for taking the knitted fabric out of the flat bed knitting apparatus is also provided. The variable take-up means is adapted to allow the knitted fabric to be removed from the apparatus at a rate that corresponds to the rate at which it is used.
The objects of the invention are also achieved through a process of producing one or more knitted fabrics, including complex knits (such as Jacquard and Intarsia) and complex weaves (such as cabling and other stitch constructions), through the step of independently and reciprocally driving a plurality of carriages on a single needle bed. When necessary, coordination of the plurality of carriages is achieved by preventing the carriages from interfering with each other. The knitted fabric so produced is removed from the flat bed knitting machine at different rates along the needle bed, the different rates corresponding to the rate at which the fabric is produced.
This brief summary is provided so that the nature of the invention may be understood quickly. However, the invention is described in significantly more detail in the following Detailed Description of the Preferred Embodiment in conjunction with the accompanying drawings, both of which form a complete part of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partly schematic, cross-sectional elevational view of an apparatus according to the present invention in which the connecting member for the second carriage is shown in dotted lines;
FIG. 2 is a front elevational view, partly cut away, of the apparatus of FIG. 1;
FIG. 3 is a top plan view of the apparatus of FIG. 1;
FIG. 4 is a schematic, perspective view of the apparatus of FIG. 1; and
FIG. 5, comprising FIGS. 5a, b and c, is a diagram for explaining some of the possibilities for carriage movement in an apparatus according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, front and rear needle assemblies 11 are arranged opposite one another with gap 12 therebetween so as to form needle bed 14. As is known, the needle bed includes a large number of parallel needles lowerable in respective needle grooves of the needle bed; the lowerable needles are brought into engaging positions by selector arrangements (not shown) included in carriages 15a and 15b.
Carriages 15a and 15b (see FIG. 2) are mounted for movement on the needle bed 14 by means of a support rod 16 accepted in hole 17 at the top of each of the carriages. The support rod 16 extends across the operative width of needle bed 14, and allows the carriages to be moved as desired.
Each of the carriages 15a and 15b may be provided with a plurality of knitting systems to permit more or less complicated manipulation of the needles in needle bed 14, as desired.
Various yarn feeders (not shown) are also conveniently mounted on rod 16. However, the specific manner in which yarn is provided to the carriages and the needle bed forms no part of the invention per se, and further discussion thereof will be omitted.
Referring again to FIG. 1, carriage 15a is provided at a lower inside extremity thereof with connecting member 19. The connecting member 19 permits attachment of carriage 15a to reciprocal driving means. In the present embodiment, the driving means is in the form of a toothed resilient belt 20 which, in connection with reversing drive motor 24 described herein below, permits selective adjustment of the stroke for carriage 15a, and permits reciprocal movement of carriage 15a across needle bed 14.
In a similar manner, carriage 15b is provided at the upper inside extremity thereof with a connecting member 21 that permits attachment of carriage 15b to drive means, comprising toothed resilient belt 22 and reversing drive motor 26 so as to permit selective adjustment of the stroke for carriage 15b and to permit reciprocal movement of carriage 15b across needle bed 14.
As shown in FIG. 2, toothed belt 20 is provided at its left-most extremity with reversing drive motor 24, and at its right-most extremity with a pivot point 25. Adjacent drive motor 24 is a sensor 23a that defines a home position for carriage 15a and generates a signal when carriage 15a is in its home position. In like manner, toothed belt 22 is provided at its right-most extremity with reversible drive motor 26, and at its left-most extremity with pivot-point 27. Adjacent drive motor 26 is a sensor 23b that defines a home position for carriage 15b and generates a signal when carriage 15b is in its home position. The various belts, drive motors, pivot points and sensors are provided in a mirror image arrangement so as to reduce the spacing between belts 20 and 22.
In the present embodiment, drive motors 24 and 26 are pulse motors. As known, such motors respond with a predetermined rotational angle for every pulse applied thereto. Thus, through the provision of separate carriages 15a and 15b, as well as their associated drive belts and reversible drive motors, each of the carriages is provided with fully independent reciprocal drive over the length of needle bed 14, and each carriage may be moved at mutually different speeds.
Each of motors 24 and 26, as well as carriages 15a and 15b, are operated under the control of a controller, preferably a digital microcomputer. The controller is shown schematically at 29. Control over one carriage to direct its knitting task and over its associated drive to move the carriage appropriately is conventional and a detailed description will be omitted. In the present invention, however, controller 29 is provided with two such controls, one for each of carriages 15a and 15b and their associated drive means. As such, controller 29 is capable of independently controlling carriages 15a and 15b with respect to their relative knitting tasks, and is capable of independently controlling the drive means associated with carriages 15a and 15b so as to move the carriages independently and at different speeds, as appropriate.
In addition to individual control over the drive motors and the carriages, the controller permits coordination between the operation of carriages 15a and 15b. That is, since the full bed is available to both carriages 15a and 15b, means must be provided to prevent the carriages from interfering with each other. Such means permit both carriages to operate simultaneously to produce complex patterns, weaves or shapes in a single knitted fabric, or permit the carriages collectively to use the entire operative width of the needle bed 14 to produce a plurality of knitted fabrics. By preventing carriages 15a and 15b from interfering with each other, the knitted fabric being produced by carriage 15a can be closely placed to the knitted fabric being produced by carriage 15b, since there is no need to be concerned about collision of the carriages.
In the present embodiment of the invention, the means for preventing interference between the heads is provided by a position monitor within controller 29 for each of the carriages. The position monitor functions in accordance with the control exerted over drive motors 24 and 26 to produce a signal indicative of the position of each of carriages 15a and 15b. More specifically, by counting the pulses, both positive and negative, that are applied to drive motors 24 and 26, a signal may be formed for each motor that indicates the relative displacement of each carriage from its home position, as determined by signals from sensor 23a and 23b.
By properly considering the width of each of carriages 15a and 15b, controller 29 can exert control over drive motors 24 and 26 in such a manner that carriages 15a and 15b will not interfere with each other. For example, by assigning carriage 15a a higher priority for control than that for carriage 15b, the movement of carriage 15b can be subordinated to that of carriage 15a. Thus, if the carriages are being moved toward each other, the position monitor will allow controller 29 to anticipate that the carriages will interfere with each other, and temporarily stop movement of carriage 15b until carriage 15a has completed its movement and is at a position where it will not interfere with further movement of carriage 15b.
Other means for preventing interference of the carriages are also possible. For example, if it is not important to utilize the entire useful area of needle bed 14, mechanical stops may be provided at appropriate positions on the needle bed to prevent the carriages from moving beyond predetermined boundaries.
As a further example of a means for preventing, an area detector actuated by movement of the carriages may be placed at potentially interfering areas. This detector would define a "hot zone" which, once entered by one of the carriages, would signal to controller 29 that the other carriage should be kept clear of the "hot zone".
FIG. 5 is a diagrammatic representation of the versatility of an apparatus according to the present invention. In FIG. 5, single headed arrows depict movement of carriage 15a, while double headed arrows depict movement of carriage 15b. As shown, for example, in FIG. 5a, carriages 15a and 15b can be moved in opposite directions relative to each other while executing different or the same tasks. If the widths of both knitted fabrics are the same, the carriages will remain more-or-less in coordination with each other.
As shown in FIG. 5b, however, when knitted fabrics of different widths are produced, carriage 15b can move to-and-fro on the needle bed much more rapidly than carriage 15a. Operation in this manner clearly allows more efficient production from the knitting machine.
Finally, in FIG. 5c, carriage 15a can be utilized in cooperation with carriage 15b to produce complex patterns, weaves or shapes in the knitted fabric, such as Jacquard, Intarsia, cabling, etc. Thus, as shown in FIG. 5c, when carriage 15b is off to the right and not in a position to interfere with carriage 15a, carriage 15a may be brought over to the complex knitted fabric and perform a knitting operation there. As it is moved away from the complex knitted fabric, carriage 15a is no longer in a position to interfere with carriage 15b, and carriage 15b may thereby be brought to complete the pattern, weave or shape. Meanwhile, as carriage 15a is away from the complex pattern, it may be used to knit a more simple pattern in another area of the needle bed 14.
As will be evident from the foregoing description, the great versatility of an apparatus according to the present invention will yield knitted fabrics from the flat bed knitting machine at vastly different rates. It is therefore necessary to provide take-up means that extend across the length of needle bed 14 and that take-up knitted fabric at a rate that is equal to the rate at which the knitted fabric is produced.
A suitable form for such variable take-up means is shown in FIG. 1. As fabric 28 is produced from gap 12, it is received between two counter-rotating rollers 32. The rollers 32 are loosely and frictionally coupled to shaft 34 which provides the rotating drive force for the rollers. Because there is no rigid attachment between the rollers 32 and the drive shaft 34, the rollers 32 slip with respect to rotation of drive shaft 34, to provide a suitable tension for fabric 28 as it is produced by machine, and to allow the fabric to be taken up in an "on-demand" basis.
As further shown in FIG. 2, the take-up mechanism is segmented into short segments 35 along the length of needle bed 14. Thus, the take-up mechanism comprises a plurality of short segments 35 of rollers 32. Each segment operates independently of the other segment since each segment is slip fit with respect to shaft 34. Thus, a variable take-up mechanism is provided across the length of needle bed 14.
The above description of the preferred embodiment, and indeed the best embodiment known to me, has been provided so that a detailed understanding of the present invention may be obtained. However, modifications of the embodiment that do not depart from the scope of the appended claims should be evident to those skilled in the art. For example, the independent drive means for each of the plurality of carriages need not be arranged in a mirror-image fashion, as described above. Instead, one carriage can expediently be provided with a drive means above needle bed 14, while the other can be driven from below the needle bed 14. Similarly, while a toothed belt driven by reversible drive motors has been shown as the drive means for the carriages, suitable replacements, for example a self-contained drive motor within the carriage driving a gear that bears against a fixed gear, will readily be appreciated by those skilled in the art.
Similarly, other modifications of the invention will be apparent to those skilled in the art, and the embodiment described above should not be considered as limiting but only illustrative. Instead, the scope of the invention should be determined solely with reference to the claims attached hereto.
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A flat bed knitting machine having plural carriages that are independently controllable, preferably both as to movement along a needle bed and as to the knitting task performed thereby. A separate driver is provided for each of the carriages to move the carriages independently and reciprocally along the needle bed. A preferred embodiment includes a device for preventing the carriages from interfering with one another as they are moved along the needle bed.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for forming a nozzle employed in continuously casting for the purpose of obtaining a mold member of a submerged nozzle, a long nozzle or the like.
In general, the nozzle employed in continuously casting is constituted by employing various powdered refractory materials having different characteristics in a body portion, an edge portion, an inner hole portion, and a powder (slag line) portion in accordance with a necessary function on practical use. A mold member of a conventional nozzle of this type is obtained through a process of filling with necessary powdered refractory materials regulated in grain size one after another while employing a suitable dividing plate inside a rubber mold charging a mandrel (metal mold), and then pressing with hydrostatic pressure.
Particularly, as shown in FIG. 9, a lower end portion of a cylindrical rubber mold 21 is blocked with a disk-shaped rubber mold 22. A mandrel 23 is charged into the cylindrical rubber mold 21, so that a cylindrical mold hole is formed between the cylindrical rubber mold 21 and mandrel 23. A powdered refractory material 25 for the edge portion is filled to a predetermined height inside the cylindrical mold hole, while employing a hopper 24 mounted on an upper end portion of the cylindrical rubber mold 21. Furthermore, a powdered refractory material 26 for the body portion is filled to a predetermined height.
At the next step, a cylindrical dividing plate 27 is concentrically arranged on an outer periphery of the mandrel 23, so that a cylindrical space is formed between the dividing plate 27 and mandrel 23. A powdered refractory material 28 for the inner hole portion is filled to a predetermined height inside the cylindrical space, while employing a hopper (not shown) mounted on an upper end portion of the dividing plate 27. Furthermore, the hopper is removed, and then an upper end portion of the dividing plate 27 is blocked with a disk-shaped dividing plate 29.
At the further step, the cylindrical dividing plate 27 is concentrically arranged on an outer periphery of the mandrel 23. A powdered refractory material 28 for the inner hole portion is filled to a predetermined height inside a cylindrical space formed between the cylindrical dividing plate 27 and rubber mold 21, while employing a hopper 24 mounted on a upper end portion of the rubber mold 21. Furthermore, a powdered refractory material 30 for the powder portion is filled to a predetermined height, and then the powdered refractory material 26 is filled to the height equal to the powdered refractory material 28 for the inner hole portion.
Next, after the disk-shaped dividing plate 29 is removed and the cylindrical dividing plate 27 is released, the powdered refractory material 26 for the body portion is filled to a predetermined height. Furthermore, as shown in FIG. 10, the upper end portion of the cylindrical rubber mold 21 is blocked with the disk-shaped rubber mold 31, and then each powdered refractory materials is formed by pressing with hydrostatic pressure.
As shown in FIG. 11, each of the rubber molds 21, 22 and 31 is released after pressing with hydrostatic pressure. The mandrel 23 is further released, so that a mold member 32 for the continuous casting nozzle is formed as shown in FIG. 12. Finally, the mold member is mechanically processed into the nozzle employed in continuously casting by machining appearances and holes thereon after firing.
However, the conventional method for forming the nozzle employs the dividing plates for filling each powdered refractory material at the necessary position as described above. Therefore, there is a problem that the forming process is complicated, and the powdered refractory materials segregate at boundary portions thereof, due to releasing of the dividing plates. Moreover, there is another problem in that the powdered refractory material for each portion is incorrectly arranged.
SUMMARY OF THE INVENTION
With the above problem and difficulty accompanying the conventional method for forming a nozzle employed in continuously casting, an object of the present invention is to provide a method for forming a nozzle employed in continuously casting in which the forming process is simplified, powdered refractory materials do not segregate at boundary portions thereof. Moreover, another object of the present invention is to provide the method for forming the nozzle employed in continuously casting in which the powdered refractory material for each portion is correctly arranged at the desired position.
To achieve the above object, according to the present invention, the method for forming the nozzle employed in continuously casting is provided through a process in which necessary powdered refractory materials are pressed with lower hydrostatic pressure, thereby to form preliminary mold members or preforms for an edge portion, an inner hole portion, and a powder line portion, and then these preforms are combined one after another while filling a powdered refractory material for a body portion by employing a suitable mandrel inside a rubber mold, and a substantial mold member or nozzle configuration is formed by pressing with higher hydrostatic pressure.
According to the method of the present invention, a surface of the preform for each portion operates as a dividing member between the powdered refractory material for the body portion and the preform.
A forming pressure for a preliminary mold member or preform (lower hydrostatic pressure forming) is desired to be 250 Kgf/cm 2 in terms of handling efficiency and adhesiveness.
A forming pressure for a substantial mold member or nozzle configuration (higher hydrostatic pressure forming) is desired to be 1500 Kgf/cm 2 in terms of quality characteristic value and joint strength for each portion.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings;
FIG. 1 is a partially broken plan view showing a preliminary mold member or preform for an edge hole portion, obtained at a previous step according to an method for forming a nozzle employed in continuously casting of the present invention;
FIG. 2 is a partially broken plan view showing a preliminary mold member or preform for an inner hole portion, obtained at the previous step according to the method of the present invention;
FIG. 3 is a partially broken plan view showing a preliminary mold member or preform for a powder line portion, obtained at the previous step according to the method of the present invention;
FIGS. 4 to 7 are partially broken plan views showing later steps combining the preliminary mold members or preforms one after another while filling a powdered refractory material according to the method of the present invention;
FIG. 8 is a partially broken plan view showing a substantial mold member or nozzle configuration formed after pressing with higher hydrostatic pressure according to the method of the present invention;
FIGS. 9 to 11 are partially broken plan views showing each step for forming a mold member according to a conventional method; and
FIG. 12 is a partially broken plan view showing the mold member formed according to the conventional method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of a method for forming a nozzle employed in continuously casting according to the present invention will now be described in detail with reference to accompanying drawings.
A powdered refractory material (for example, alumina-carbon-zirconia series) for an edge portion is filled inside a rubber mold charging a mandrel, and then pressed with lower hydrostatic pressure of about 250 Kgf/cm 2 , so that a preform 1 for the edge portion is formed as shown in FIG. 1. On the other hand, a powdered refractory material (for example, alumina-carbon-zirconia series) for an inner hole portion is filled inside a rubber mold charging a mandrel, and then pressed with lower hydrostatic pressure of about 250 Kgf/cm 2 , so that preform 2 for the inner hole portion is also formed as shown in FIG. 2. Furthermore, a powdered refractory material (for example zirconia-carbon series) for a powder line portion is filled inside a rubber mold charging a mandrel, and then pressed with lower hydrostatic pressure of 250 Kgf/cm 2 , so that a preform 3 for the powder line portion is further formed as shown in FIG. 3. As a result, the preforms 1, 2, and 3 are obtained by operating the above forming process separately. Moreover, a surface roughing process is performed with a sandblast on joint surfaces thereof corresponding to a powdered refractory material for a body portion as described in the following.
As shown in FIG. 4, a lower end portion of a cylindrical rubber mold 4 is blocked with a disk-shaped rubber mold 5. After a mandrel 6 is charged thereinto, the preforms 1 for the edge portion is received inside the rubber mold 4 while engaging with the mandrel 6 so that the surface on which the surface roughing process was preformed is an upper surface. Furthermore, a powdered refractory material 7 (for example, alumina-carbon series) for the body portion is filled to the predetermined height in a space formed between the rubber mold 4 and mandrel 6, while employing a hopper (not shown) mounted on an upper end portion of the rubber mold 4. Moreover, the preforms 2 for the inner hole portion is received inside the rubber mold 4 while engaging with the mandrel 6 and contacting to the powdered refractory material 7 for the body portion, and then the powdered refractory material 7 is filled to the predetermined height as shown in FIG. 5.
As shown in FIG. 6, the preform 3 for the powder line portion is received inside the rubber mold 4 while engaging with the preform 2 for the inner hole portion and contacting to the powdered refractory material 7. Furthermore, the powdered refractory material 7 is filled to the predetermined height. Moreover, the upper end portion of the cylindrical rubber mold 4 is blocked with a disk-shaped rubber mold 8 as shown in FIG. 7, and then pressed with higher hydrostatic pressure of about 1500 Kgf/cm 2 .
As shown in FIG. 8, each of the rubber molds 4, 5 and 8 is released after pressing with higher hydrostatic pressure, so that a substantial mold member nozzle configuration 9 for the necessary nozzle is formed. Furthermore, the nozzle containing all necessary features for use in continuously casting is obtained by mechanically processing required appearances and holes thereon after the nozzle configuration 9 is fired. The nozzle formed as described above has a mechanical strength one and a half times as strong as that obtained by firing a mold member formed by means of the conventional method.
Although the preforms 1, 2, and 3 are formed by pressing with lower hydrostatic pressure of about 250 Kgf/cm 2 in the first embodiment as described above, according to second embodiment of the present invention, the preforms 1, 2, and 3 are formed by pressing with hydrostatic pressure of about 200 Kgf/cm 2 . The nozzle formed from the mold members of the second embodiment has a mechanical strength 1.3 times as strong as that obtained by means of the conventional method.
To raise the joint strength of the preforms joining to each other and between the powdered refractory material for the body portion and the preform, a surface roughing process is desirable to perform on the joint surface thereof. The surface roughing process is achieved by roughing the joint surface after the preform is formed. As the other surface roughing process, is minute unevenness is previously provided onto a surface of the mandrel (metal mold) or the rubber mold for the preform.
Moreover, to raise the joint strength of the preforms joining to each other and between the powdered refractory material and the preform a small amount of an addition of a pitch, a boron carbide (B 4 C) or the like is desirable to add to the boundary portion. A mortar or the other application may be applied on the joint surface thereof.
Table 1 described in the following shows the characteristics of examples 1 and 2 according to the first and second embodiments of the present invention, respectively. Table 1 further includes a comparative example of the present invention and conventional example for a comparison.
TABLE 1______________________________________ Compar- Conven- Example Example ative tional 1 2 example example______________________________________Preliminary formingpressure (Kgf/cm.sup.2)preform1 250 200 150 Not2 250 200 150 Prelimi-3 250 200 150 narily formingProducts strength 1.5 1.3 1.1 1.0ratioSegregation in None None None Onegrain size pointDeviation of an Maxi- Maxi- Maxi- Maxi-arranged height mum mum mum mum 2 mm 2 mm 3 mm 20 mmDegree of an None None None Maxi-eccentricity mum 2 mm______________________________________
In Table 1, the comparative example needs the difficulty to handle particularly thin products due to the small joint strength of the preforms. The characteristics of each example are shown in the following manner. The number of the preform corresponds with FIGS. 1 to 3. The products strength ratio is a ratio of a compressing strength letting that of conventional products be 1.0. The segregation in grain size is compared by eyes through a X-ray fluoroscopy. The deviation of the arranged height is measured through a X-ray fluoroscopy. The degree of the eccentricity is measured through a X-ray computerized tomography. The forming pressure for the substantial mold member is 1500 Kgf/cm 2 in all examples.
As described above, according to the present invention, since a surface of the preform for each portion operates as a dividing member between the powdered refractory material for the body portion and preliminary mold member, the method of the present invention does not require a dividing plate as employed in the conventional method. Therefore, the method of the present invention can effectively simplify the forming process without segregating the powdered refractory materials at boundary portions thereof and producing traces. Moreover, the method of the present invention can arrange the powdered refractory material for each portion at the desired position.
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A method for forming a nozzle employed in continuous casting is provided in which powder refractory materials are pressed with low hydrostatic pressure to produce preforms for an edge portion, an inner hole portion, and a powder line portion, these preforms are combined one after another in a rubber mold employing a mandrel while filling the rubber mold with a powdered refractory material for a body portion of the nozzle, and then a nozzle configuration is formed by pressing the rubber mold with a higher hydrostatic pressure than that used to produce the preforms.
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BACKGROUND OF THE INVENTION
The present invention relates to a needle selection structure for a circular knitting machine, and more particularly to such a needle selection structure which is suitable for use in a rib knitting machine or interlocking knitting machine for a yarn into a ribbed or interlocking fabric.
A ribbed fabric has a certain flexibility and thickness, and is suitable for making clothes. When using a ribbed fabric to make clothes, it is not necessary to iron or calender the ribbed fabric because the rib border of a ribbed fabric does not curve. Because a ribbed fabric can easily be cut subject to the desired pattern, it is widely accepted by overcoat manufacturers. Because a rib-knitting machine is comprised of two sets of needles, it is superior over a plain knitting machine in pattern variation. A rib knitting machine is practical for knitting elastic fabric for making clothes, as well as for knitting a rib collar, rib cuff, rib trim, rib top, etc. Further, an interlocking knitting machine is similar to a rib-knitting machine. In early days, interlock fabrics were used for making underwear. Nowadays, interlock fabrics have been intensively used for making clothes. When a rib knitting machine or interlocking knitting machine is operated to knit a fabric, cylinder needles are lifted by cylinder cam, and plate needles are pushed outwards by a needle cam at a cover plate. The pattern formed by the knitting operation of the plate needles and the cylinder needles is determined subject to the paths of the cylinder cam and the needle cam. When changing to another pattern, the paths of the cylinder cam and the needle cam must be changed. It is time and labor consuming to change the path of the cylinder cam and the needle cam.
SUMMARY OF THE INVENTION
The present invention has been accomplished under the circumstances in view. The present invention provides a computer-controlled selection unit installed in the knitting machine. The needle selection unit is controlled by an external computer to drive plate needles, causing the plate needles to match with cylinder needles in knitting a yarn into a ribbed or interlocking fabric. According to the present invention, the needle selection structure comprises a computer-controlled needle selection unit. The computer-controlled needle selection unit comprises a selecting device, and a set of selection jacks driven by the selecting device. The selecting device is controlled by an external computer, having a plurality of needle selection legs corresponding to the butt at each of the selection jacks. Each needle selection leg has a sloping face for the passing of the butt of the corresponding selection jack. Each selection jack comprises a jack body moved on the upper needle dial. The jack body comprises a front coupling portion for coupling to a rear coupling portion at the rear end of the corresponding plate needle, a rear guide butt moved with the jack body in a track at a cap, and a bearing butt spaced between the front coupling portion and the rear guide butt for pushing by one needle selection leg of the selecting device. The cap is provided beneath the cover plate, comprising a track, which receives each selection jack, and a return portion sloping in one direction for guiding the rear guide butt of the selection jack back to the cap.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing showing the position of the computer-controlled selector unit at the upper needle dial.
FIG. 2 is an extended out view of FIG. 1.
FIG. 3A is a side view of the present invention.
FIG. 3B is similar to FIG. 3A but showing the computer-controlled selector unit operated.
FIG. 3C is a top view of FIG. 3A.
FIG. 3D is an enlarged view of a part of FIG. 3C.
FIGS. 4A-4C show the knitting operation of the plate needles and the cylinder needles according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a computer-controlled needle selection unit is designed for use in a rib-knitting machine or interlocking knitting machine The knitting machine comprises a needle dial 1, a set of plate needles 2 arranged on the needle dial 1, a needle cylinder 3, and a set of cylinder needles 4 arranged on the needle cylinder 3. During knitting, the cylinder needles 4 are lifted by a needle lifting cam (not shown), and plate needles 2 are pushed outwards by a needle push jack at a cover plate 5, therefore loop-forming knitting are simultaneously or alternatively achieved. However, this knitting method can only produce a single ribbed or interlocking texture. In order to provide the ribbed or interlocking texture with a jacquard pattern, the present invention adds a computer-controlled needle selection unit 6 to the cover plate 5 above the upper needle dial 1.
The computer-controlled needle selection unit 6 comprises a selecting device 61, and a set of selection jacks 62 driven by the selecting device 61. The selecting device 61 is controlled to operate by an external computer, having a plurality of needle selection legs 611. Each of the needle selection legs 611 has a sloping face 612. Each selection jack 62 comprises a jack body 622 moved on the upper needle dial 1. The jack body 622 comprises a front coupling portion 623 for coupling to a rear coupling portion 21 at the rear end of the corresponding plate needle 2, a rear guide butt 624 moved with the jack body 622 in a track 71 at a cap 7, and a bearing butt 621 spaced between the front coupling portion 623 and the rear guide butt 624 for pushing by one needle selection leg 611 of the selecting device 61.
The cap 7 is provided beneath the cover plate 5, comprising a track 71, which receives the selection jack 62, and a return portion 72 sloping in one direction for guiding the rear guide butt 624 of the selection jack 62 back to the cap 7.
Referring to Figures from 3A through 3D, during loop knitting, the cylinder needles 4 are lifted by the needle cam (not shown) at the needle cylinder 3, and the plate needles 2 are pushed outwards by the needle cam 8 at the front side of the cover plate 5, thereby causing the plate needles 2 and the cylinder needles 4 to alternatively hook up the yarn 9, then the plate needles 2 are retracted and the cylinder needles 4 are lowered, thereby causing loops to be alternatively or simultaneously formed (see FIGS. 4A, 4B and 4C).
When the external computer is operated to control the selecting device 61, the needle selection legs 611 are turned up and down. When turning upwards, the needle selection legs 611 are moved to the selection jack 62, and the sloping face 612 of one needle selection leg 611 is pressed on the bearing butt 621 at the selection jack 62, causing the selection jack 62 to sink (see FIGS. 3B and 3C). When the selection jack 62 is lowered, the rear guide butt 624 of the selection jack 62 is moved away from the track 71 at the cap 7 (see FIG. 3D), and therefore the rear guide butt 624 of the selection jack 62 passes through the outside of the track 71, and the selection jack 62 does not push the corresponding plate needle 2 to make a jacquard knitting, i.e., the corresponding plate needle 2 is reciprocated in the track 81 at the needle cam 8. After the end of the aforesaid action, the return portion 72 of the cap 7 guides the guide butt 624 of the selection jack 62, thereby causing the selection jack 62 to be moved back to the cap 7.
When turning downwards, the needle selection legs 611 are moved through the gaps between each two selection jacks 62, and the guide butt 624 is moved with the respective selection jack 62 in the track 71 at the cap 7, and when the cam 711 of the track 71 is moved to the guide butt 624, the corresponding plate needle 2 is pushed outwards by the cam 82 at the track 81 at the needle cam 8 to achieve a jacquard knitting action.
As indicated above, when the selection jack 62 is not selected, the corresponding plate needle 2 achieves a jacquard knitting at the cam 711 in the track 71 at the cap 7. If the selection jack 62 is selected, the corresponding plate needle 2 is moved subject to the track 81 at the needle cam 8. Under the control of the external computer, the computer-controlled needle selection unit 6 is operated to selectively move the plate needles 2, causing the plate needles 2 and the cylinder needles to knit the yarn into a ribbed or interlocking fabric.
While only one embodiment of the present invention has been shown and described, it will be understood that various modifications and changes could be made thereunto without departing from the spirit and scope of the invention disclosed.
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A needle selection structure used in a rib knitting machine or interlocking knitting machine, which includes a computer-controlled needle selection unit arranged on a cover plate above a needle dial, and controlled by an external computer to move selection jacks, enabling plate needles to be selectively extended out to act with cylinder needles in knitting a yarn into a ribbed or interlocking fabric.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of copending U.S. patent application Ser. No. 07/609,683, filed Nov. 6, 1990, now abandoned.
FIELD OF THE INVENTION
This invention relates to reactors in which fluid reactants flow through a bed of catalytic material More particularly, it relates to a method and means for redistributing flow through the bed.
BACKGROUND OF THE INVENTION
The design of reactors used in chemical processes varies widely in accordance with the particular reactions taking place. In general, however, most involve the use of at least one bed of catalyst particles through which the reactants flow. The catalyst particles are supported on a grate or other open support means which enables fluid to flow through the catalyst bed and its support to the reactor outlet. A fluid distribution device is normally provided between the reactor inlet and the catalyst bed in order to uniformly distribute fluid to the catalyst bed.
Despite the initial uniform flow of fluid into the catalyst bed, higher localized flow rates within the bed are quite often encountered, causing less than optimum operation of the reactor since the time of contact of the reactants with the catalyst material will vary depending upon the section of the catalyst bed through which the reactants flow. Measures to provide a more uniform reactor flow have been suggested, but these typically involve the use of complicated mechanical designs for altering and controlling fluid flow prior to entry into the catalyst bed. Although satisfactory to a degree, such measures still are not capable of satisfactorily controlling the flow within the catalyst bed itself.
It would be desirable to be able to efficiently control reactor flow within the catalyst bed to make it more uniform, and to do so by economical means which does not require a special design of reactor.
BRIEF SUMMARY OF THE INVENTION
The invention provides means for applying a uniform flow resistance across a catalyst bed so that any localized high flow rates will encounter higher flow resistance than at other locations, causing a redistribution of the flow to a more uniform pattern. This is carried out by providing a transversely extending layer of spaced barriers to fluid flow within the catalyst bed. The barriers are structurally unconnected to the reactor, thus obviating the need for a special reactor design. The spacing between the barriers is such that the barriers do not impede flow through the catalyst bed, but will cause localized high flow currents encountering them to be slowed.
Preferably, the barriers take the form of disks attached to a support, such as a mat. The disks are made of a material which is able to withstand the operating conditions of the reactor while the support is made of a material which is unable to withstand one or more of the operating conditions, such as temperature, pH or some other condition. After placing the support within the bed and activating the reactor, operating conditions are reached within the reactor which destroy the support, leaving the disks in place to provide the desired flow resistance. The disks can be removed from the reactor upon removing the spent catalyst particles.
The cost of the flow redistribution means of the invention is minimal, yet the invention provides the necessary degree of flow resistance to obtain a more uniform flow pattern through the reactor without interfering with the operation of the reactor.
The various features of the invention which enable more uniform flow through a reactor to be achieved are brought out in more detail in the description which follows, wherein the above and other aspects of the invention, as well as other benefits thereof, will readily be apparent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified longitudinal sectional view of a reactor incorporating the flow redistribution means of the invention;
FIG. 2 is an enlarged view of the area enclosed in the circle 2 of FIG. 1;
FIG. 3 is an enlarged sectional view taken on line 3--3 of FIG. 2;
FIG. 4 is a pictorial view of a mat to which the disks used as flow barriers are attached;
FIG. 5 is an enlarged sectional view taken on line 5--5 of FIG. 4;
FIG. 6 is a sectional view similar to that of FIG. 2, but showing the disks in place within a catalyst bed before the reactor has been activated; and
FIG. 7 is a plan view of a portion of a support mat, showing disks of different shape.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a reactor 10 comprises a vessel 12 having an inlet 14 at one end and an outlet 16 at the other end. Although structure denoting the particular operational details of the reactor have not been shown since it is not pertinent to the invention, it will be understood that the reactor would be provided with all the necessary accessories, including conduits, heaters and controls, to make it operable. A catalyst bed 18 is supported on grate 20, which includes open areas 21, while an upper frame 22, also including open areas 23, is in contact with the upper end of the bed. The frame 22 may be designed to distribute reactant fluid uniformly over the surface of the catalyst bed 18 or additional structure may be provided for this purpose. In either case, the normal design of the reactor would provide for such uniform distribution of the fluid.
Referring to FIGS. 1, 2 and 3, in accordance with the invention a layer 24 of spaced disks 26 is provided intermediate the ends of the catalyst bed. The disks are located so that fluid flowing down through the upper portion of the bed 18 will contact them and be forced to flow around them through the spaces between them. As illustrated, the disks are embedded among the catalyst particles P and are greater in diameter than the diameter of the particles, with the spaces between the disks preferably also being greater than the size of the particles. This arrangement maintains the reactant fluid in contact with the catalyst particles throughout its path through the catalyst bed. Moreover, any tendency for fluid to flow more rapidly through one section of the bed than another will be met by an increase in pressure, with a corresponding resistance to flow, which is felt by the fluid in the area in question as it encounters the disks. This causes the fluid to seek other less resistant paths and results in a smoothing or redistribution of the flow to a more uniform pattern.
In order to place the disks in a catalyst bed so that they are properly spaced and in their desired locations, the disks 26 are attached to a flexible support such as the mat 28 shown in FIG. 4. The flexible support will provide negligible flow resistance to fluid flow through reactor 10. Accordingly, mat 28 is preferably a mesh, network or screen constructed from, for example, plastic, silk, synthetic fibers, such as, nylon or rayon, or mixtures thereof. Further exemplary, the screen may have 1 cm dimensioned apertures uniformly spaced across the dimensions thereof. The apertures present in the screen may have any suitable peripheral configuration as will be evident to the skilled artisan. In the illustration of FIG. 5, the disks are attached to the mat 28 by adhesive 30. Any other suitable attachment means may be used, such as for example by attaching the disks to a plastic mat by means of a heat seal. The mat is preferably flexible because a flexible form facilitates placement in the catalyst bed. Consistent with this, the mat 28 is depicted in FIG. 4 as being in roll form.
The disks are comprised of a material which can tolerate the operating conditions, such as high temperatures, acidity, alkalinity, etc., encountered in a reactor, while the support mat is comprised of a material which cannot tolerate all such conditions and which disintegrates when exposed to the condition it cannot tolerate. For example, the mat may melt at temperatures encountered in a reactor, may be solubilized by fluids in the reactor, may be solubilized by an acidic or basic fluid in the reactor, or may be otherwise destroyed by some intolerable condition encountered in the reactor. The disks are installed by placing the mat 28 and attached disks 26 on the bed of catalyst particles at an intermediate point in the construction of the bed, and then completing the construction of the bed. Preferably, the mat should extend out to the walls of the reactor vessel 12 in order to locate the disks across the entire bed. This leaves the mat and attached disks in the condition shown in FIG. 6, lying intermediate the ends of the catalyst bed in a location within the bed as illustrated by the layer of disks in FIG. 1.
Within a relatively short period of time after activating the reactor e.g., less than one hour, the mat material will be melted or otherwise destroyed due to its inability to tolerate the condition(s) within the reactor, leaving the disks in place, spaced according to the same spatial relationship as when they were attached to the mat. It will be understood that the spatial relationship of the disks may be engineered specifically for each application. The disks are able to remain in position during operation of the reactor due to the weight of the catalyst particles holding them in place and to the shifting of the particles into the spaces between the disks as the mat is destroyed, thereby preventing the disks from shifting. It will also be understood that the mat will not discernibly affect fluid flow through the reactor during the relatively short period of time after reactor activation and before the intolerable condition(s) within the reactor are achieved and the mat is destroyed.
The disks may be formed from any material capable of withstanding the operating conditions of the reactor and capable of being produced in the desired shape and dimensions. A suitable ceramic material or catalyst be used to form the disks. Preferably the disks are formed from the same catalyst composition used for the particles of the catalyst bed.
As previously indicated, the disks should be of a size to provide greater flow resistance than the particles are able to provide in order to redistribute the flow when local high flow rates occur. This means that they should be larger in diameter than the size of the catalyst particles. In a typical arrangement, in a catalyst bed employing particles having an average size of 1/4 inch, circular disks having a diameter of 1 inch may be provided on 11/2 inch centers. This leaves a 1/2 inch gap between the closest points of adjacent disks and ensures that the layer of disks, while providing the desired level of flow resistance, does not interfere with the continuous flow of fluid through the reactor. Such an arrangement also enables the disks to be removed along with the spent catalyst particles through the catalyst exhaust nozzle 32 shown in FIG. 1. The exhaust nozzle is illustrated as being located above the catalyst support grate 20 to enable removal of the relatively large disks. The nozzle may instead be located below the catalyst bed, if preferred, in which case a bed of inert support balls of a size capable of passing through the exhaust nozzle would be provided to support the bed of catalyst particles. Such an arrangement, which is well known to those skilled in the art, would permit removal of the disks along with the support balls. The disks in addition should be of such thickness as to provide adequate strength to resist the stresses to which they might be subjected during attachment to the mat and installation in the catalyst bed. A thickness of about 1/4 inch would be typical.
Although the disks shown in FIGS. 1-6 of the drawing are circular in shape, they may be provided in other shapes as well. For example, the arrangement of FIG. 7, wherein square disks 34 are attached to the support mat 28, may be used. Still other shapes, such as any polygonal form, may be employed, keeping in mind that whatever their shape the disks still have to be properly sized and spaced to permit the desired flow during operation of the reactor. As applied to shapes other than circular, the disks should be spaced apart a distance greater than the average diameter of the catalyst particles, and the average diameter or width of the disks should be greater than the average diameter of the catalyst particles.
The invention has been described in connection with the illustrations in the drawing wherein a single layer of disks is provided at an intermediate point shown as being at the approximate midpoint of the length of the catalyst bed. It should be understood that while this arrangement may be preferred in some reactors, other locations may be preferred in other reactor installations. A main consideration is to locate the layer of disks at a point where they are able to best provide the amount of flow resistance necessary without hindering the continuous flow of fluid through the reactor. Another consideration is to locate the layer at a point where the weight of the catalyst particles above the disks is sufficient to hold the disks in place. This may correspond to the midpoint of the catalyst bed, but it does not necessarily have to be there. If the flow objectives are better met with a layer of disks closer to one of the ends of the catalyst bed than the other, that arrangement would be contemplated by the invention. If it is found necessary to provide more than one layer of disks in order to best accomplish the flow objectives of a particular reactor, the invention is also broad enough to encompass such an arrangement.
Although the invention has been described in connection with a vertical reactor, the layer of disks can be incorporated in other reactor alignments as well. For example, if a normally horizontal reactor would benefit from the flow concepts of the present invention, the layer of disks could be incorporated in the catalyst bed provided that sufficient pressure is exerted on the ends of the bed to maintain the disks in place after destruction of the support mat occurs. This vertical configuration may require use of a more rigid, but still destructable, support base instead of a flexible mat. This rigid support base provides negligible flow resistance to fluid flow through the reactor and preferably is a mesh, network or screen.
It can now be appreciated that the invention provides a novel, economical and highly effective way to redistribute the flow in a reactor to a more uniform pattern by applying a uniform flow resistance across the catalyst bed. The use of spaced disks to provide such flow resistance is possible because there is no connecting structure between the disks to interfere with the flow of reactant fluid. Further, because the layer of disks does not depend on a structural connection to the reactor vessel, the reactor structure need not be modified in order to implement the invention.
Although the invention has been described in some detail in connection with the preferred embodiment, it will be appreciated that the invention need not necessarily be limited to all such details, and that changes to certain features of the preferred embodiment which do not alter the overall basic function and concept of the invention may be made without departing from the spirit and scope of the invention as defined in the claims.
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Method and means for redistributing fluid flow through a catalyst bed in a reactor by applying uniform flow resistance. A mat to which a series of uniformly spaced disks are adhered is placed within the catalyst bed. The disks are formed of a material capable of withstanding the temperatures within the reactor, while the mat is formed of a material which is not. The mat is destroyed by the heat of the reactor, leaving the disks in place. Localized high flow rates are smoothed out by the flow resistance provided by the disks, with flow taking place between the disks. Since the disks are small relative to the opening used to dump the spent catalyst, special consideration for disk recovery and handling are not necessary as the disks flow out the opening with the spent catalyst.
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